Staphylococcus

J Infect Dis, 1996 Oct, 174(4), 777 - 85
Differential activation of extracellular signal-regulated kinase (ERK) 1, ERK2, p38, and c-Jun NH2-terminal kinase mitogen-activated protein kinases by bacterial peptidoglycan; Dziarski R et al.; Soluble staphylococcal peptidoglycan (sPGN) is an inducer of cytokine secretion and may activate macrophages through the CD14 lipopolysaccharide (LPS) receptor . To elucidate sPGN-activated signal transduction pathways, stimulation of mitogen-activated protein (MAP) kinases by sPGN was studied in mouse RAW264.7 macrophages . sPGN strongly activated extracellular signal-regulated kinase (ERK) 1 and ERK2, moderately activated c-Jun NH2 terminal kinase (JNK), and weakly activated p38 MAP kinase, in contrast to LPS, which strongly activated all of these kinases, and phorbol 12,13-dibutyrate (PDB), which strongly activated ERK1 and ERK2 but did not activate p38 or JNK . sPGN- and LPS-induced activation of ERK1 and ERK2, unlike PDB-induced activation, was sensitive to inhibition by herbimycin A and insensitive to inhibition by increased intracellular cAMP . These results demonstrate differential activation of MAP kinases by sPGN, similar but not identical activation of signal transduction pathways by sPGN and LPS, and different mechanisms of MAP kinase activation by bacterial stimulants and phorbol esters.

J Bacteriol, 1996 Oct, 178(20), 6070 - 3
IS257-mediated cointegration in the evolution of a family of staphylococcal trimethoprim resistance plasmids; Leelaporn A et al.; Analyses of the Staphylococcus epidermidis multiresistance plasmids pSK697 and pSK818 have revealed them to be closely related to the trimethoprim resistance plasmid pSK639, also isolated from S . epidermidis . pSK697 and pSK818 were found to contain a cointegrated copy of a second plasmid related to the S . epidermidis multidrug antiseptic and disinfectant resistance plasmid pSK108 and the S . aureus tetracycline resistance plasmid pT181, respectively . In contrast to pSK639, both plasmids were found to contain a third copy of IS257, such that the integrated plasmids in both cases are flanked by a copy of this element . This organization and the presence of duplicated sequences at the extremities of the integrated plasmids implicate IS257 in the formation of these cointegrate plasmids . Sequence analysis of the IS257 elements from these plasmids has provided insights into the probable mechanism of cointegration, viz., nonresolved replicative transposition of IS257.

J Immunol, 1996 Oct 1, 157(7), 2982 - 8
Staphylococcal protein A simultaneously interacts with framework region 1, complementarity-determining region 2, and framework region 3 on human VH3-encoded Igs; Potter KN et al.; Staphylococcal protein A (SPA) is a B cell superantigen that binds to human VH3-encoded Igs independently of the D- and JH-encoded regions and light chain sequences . The SPA-binding structure formed by VH3-encoded Igs remains controversial . We localized the regions in a VH3-encoded Ab required for SPA binding by producing mutant Abs in the baculovirus expression system in which regions of a human-derived Ab known to bind SPA were exchanged with those from a mouse Ab of the J558 family, a family not associated with SPA binding . The pattern of SPA binding indicates not only that residues in FR1, CDR2, and FR3 are involved but also that the three regions are required to interact simultaneously with SPA for binding to occur . When any one of the three regions was replaced with the corresponding region from the nonbinding Ab, SPA binding was severely disrupted . These data indicate that SPA requires simultaneous interaction with three distinct regions of a VH3 structure, which together in three-dimensional space form an extended solvent-exposed surface . These studies more precisely define the genetic requirements for VH3-encoded Ig binding to SPA.

J Immunol, 1996 Oct 1, 157(7), 2976 - 81
Differential binding avidities of human IgM for staphylococcal protein A derive from specific germ-line VH3 gene usage; Hakoda M et al.; Human IgM that express the variable region genes of the VH3 family bind staphylococcal protein A (SPA) . We previously reported that the SPA-binding IgM can be divided into two groups based on the differential binding avidities for solid-phase SPA . To study the molecular basis for these differences, we cloned B cells from human blood by EBV transformation . The nucleotide sequences of the expressed Ig heavy chain genes were determined on 20 B cell clones that produce SPA-binding IgM . The germ-line VH3 gene usage in IgM with high avidities for SPA were distinct from the germ-line VH3 genes used in IgM with low avidities for SPA . There was no correlation in the usage of D or JH genes or in the usage of light chains in IgM according to the SPA binding avidity . These results suggest that the differential binding avidities for SPA are at least partly due to specific germ-line VH3 gene usage . An investigation of direct binding of SPA to the synthetic peptides corresponding to the portions of the variable regions of SPA-binding and non-SPA-binding IgM showed that the peptides corresponding to the VH3 family specific framework region 3 sequences had significant SPA binding capacities, while the peptides corresponding to the other subdomains and those corresponding to framework region 3 of the reported VH3 sequences from non-SPA-binding IgM showed little or no binding . It is of interest that the Ig-framework region 3 subdomain corresponds to the fourth hypervariable region, which in the TCR-beta chain has been implicated as a critical site for T cell superantigen binding.

J Immunol, 1996 Oct 1, 157(7), 2857 - 63
Regulation of superantigen-induced T cell activation in the absence and the presence of MHC class II; Lando PA et al.; To study MHC class II-dependent and -independent SAg2 activation and the relative importance of CD80/CD28 costimulation, staphylococcal enterotoxin A (SEA) was presented to T cells as a fusion protein containing the Fab fragment of an mAb directed against the CA215 glycoprotein . Chinese hamster ovary (CHO) cells transfected with HLA-DR4, CA215, and CD80, individually or in combinations, were used as presenting cells . A strong T cell proliferation was obtained when C215Fab-SEA fusion proteins were presented by CHO-DR/CD80 or CHO-CA215/CD80 double transfectants, whereas only low levels of proliferation were seen in the absence of CD80 . Large amounts of IL-2, IFN-gamma, and TNF were produced in addition to an increase in IL-2 mRNA as a result of CD80 costimulation . Only approximately 50% of the SEA-reactive T cells responded by expression of IL-2 receptor chains and by blast formation when activated with SEA in the absence of MHC class II . Reverse transcription-PCR-assisted repertoire analysis of SEA-reactive TCR V beta families showed that the CA215-dependent activation involved an expansion of fewer TCR V beta families compared with MHC class II-dependent activation . One-half of the six analyzed TCR V beta families were expanded independently of class II . This indicates that MHC class II has only a partial influence on the TCR V beta repertoire imprinted by SAg . This finding redefines the role of MHC class II in SAg presentation . It is suggested that MHC class II molecules are selected as SAg-binding molecules mainly as a suitable targeting receptor for professional APC expressing costimulatory molecules such as CD80 and CD86.

Presse Med, 1996 Sep 28, 25(28), 1276 - 80
{Outcome of cardiac valve ring abscesses after medical treatment: attempt to identify criteria of favorable prognosis}; Tribouilloy C et al.; OBJECTIVES: Identify factors predicting favorable outcome after medical management of valve ring abscesses in order to propose a surveillance schedule for conservative treatment . METHODS: A multicentric study conducted from July 1989 to February 1996 included 28 patients (mean age 64 +/- 16 years, range 26-83) hospitalized for active endocarditis and valve ring abscesses diagnosed at transthoracic or transesophageal echography . Conservative medical therapy was given because of a decision of the medico-surgical team (n = 9), high surgical risk (n = 12), or patient refusal of surgery (n = 7) . Outcome was favourable in 18 patients (Group I) and unfavorable in 10 (Group II) due to death (n = 9) or subsequent surgery (n = 1) . Univariate and multivariate analysis were used to determine differences between the groups in terms of clinical and laboratory data . RESULTS: Mean follow-up in Group I was 33 +/- 18 months and 15 +/- 10 months in Group II . Univariate analysis showed significant differences between Group I and II respectively for age (59 +/- 18 yr vs 72 +/- 10, p = 0.04), delay to apyrexia after antibiotics (4.3 +/- 2.8 vs 8.3 +/- 2.4 days, p < 0.0008), heart failure (5% vs 70%, p = 0.003), grade III or IV valvular regurgitation (5% vs 60%, p < 0.04), and mean surface area of the abscess (1.5 +/- 1.2 vs 5.4 +/- 6.4 cm2, p < 0.03) . Independent factors at multivariate analysis were by decreasing order: lack of heart failure at admission, delay to apyrexia, abscess surface area, and age . Outcome was favorable (mean follow-up 33 +/- 10 months) in all patients with an abscess surface area < 1.5 cm2, no signs of heart failure, no grade III or IV valvular regurgitation, apyrexia after less than 8 days on antibiotics and no staphylococcus positive blood culture . CONCLUSION: Medical management of valve ring abscesses may be indicated in selected patients in care units with rigorous surveillance facilities . Further studies are needed to precisely identify surveillance and treatment criteria.

Int J Cancer, 1996 Sep 27, 68(1), 109 - 13
Immune response during tumor therapy with antibody-superantigen fusion proteins; Rosendahl A et al.; To engineer superantigens (SAg) to express tumor reactivity, we genetically fused the Fab-part of the tumor-reactive MAb C215 and the bacterial SAg staphylococcal enterotoxin A (SEA) . Treatment of mice carrying established lung micrometastases of the C215-transfected syngeneic B16 melanoma with 3-4 daily injections of C215Fab-SEA resulted in strong antitumor effects, while only moderate effects were seen when treatment was given every 4th day (intermittent treatment) . High serum levels of IL-2, TNF-alpha, IFN-gamma and strong induction of CTLs (cytotoxic T lymphocytes) were noted after priming with the fusion protein . T cells responded well to 3 daily injections of C215Fab-SEA and then gradually entered a hyporesponsive state, characterized by a reduced ability to produce IL-2, TNF-alpha and IFN-gamma and failure to mediate cytotoxicity in vitro . Intermittent treatment was characterized by increased levels of IL-10, concomitant with accentuated loss of IL-2, TNF-alpha and IFN-gamma production . A 10-fold increase in SEA-reactive TCR V(beta)3+ CD4+ cells was observed in the spleen, while a loss of TCR V(beta)3+ CD8+ and V(beta)11+ CD8+ cells was noted . This is in striking contrast to injections of native SEA which induced a marked deletion of TCR V(beta)3+ CD4+ T cells, but not of CD8+ cells . Recovery of the TH1 cytokine profile occurred within 1-2 weeks, while restoration of cytotoxicity required several months and correlated with recovery of TCR V(beta)3+ CD8+ and TCR V(beta)11+ CD8+ T cells . These results show that the temporal relationship of SAg stimulations dictates the cytokine profile . Moreover, different mechanisms appear to regulate hyporesponsiveness in CD4+ and CD8+ T cells.

Cell Immunol, 1996 Sep 15, 172(2), 254 - 61
The immunodominant region of Staphylococcal nuclease is represented by multiple peptide sequences; Nikcevich KM et al.; Several published reports have lead to the characterization of naturally processed peptides that are presented in association with either class I or class II MHC molecules . Most peptides isolated from class II molecules are heterogeneous in length and exhibit ragged amino and carboxy termini . An intriguing finding was that one region of a molecule was often represented by many distinct peptides, rather than by a single dominant peptide species . Each of the peptides representing this dominant region exhibited a common core of amino acids, suggesting that this core may play a significant role in the binding of the peptide to class II and the recognition by peptide-specific T cells . Work from our laboratory has focused on the mechanisms involved in the immunodominance of antigenic determinants using the bacterial antigen Staphylococcal nuclease (Nase) as a model . Using truncated synthetic peptides, we have identified the immunodominant determinant of Nase to be located within the region 81-100 with a minimal antigenic core of 91-100 as determined . Addition of five residues to the carboxy terminus of this peptide had a negative effect on T cell recognition of this region . The present studies were undertaken in an effort to determine the sequence of the naturally processed immunodominant Nase determinant(s) presented in association with I-Ek class II . Our results indicate that the dominant region of the Nase molecule is represented by at least four distinct peptide species that are predicted to lie between residues 86 and 106 with a common core sequence of 91-96 . These results indicate that the negative effects of flanking regions are dependent upon length and amino acid composition, and thus the use of truncated peptides to study minimal antigenic determinants may be misleading.

Minerva Chir, 1996 Sep, 51(9), 707 - 11
{A rare case of primary abdominal actinomycosis}; Lazzaretti MG et al.; The authors describe a case of primary abdominal actinomycosis operated on because of peritonitis sustained by a tubo-ovarian abscess . They discuss the pathogenesis of the case: the patient had been on intrauterine device contraception till two months earlier and had been operated on for breast cancer . Preoperative diagnosis is quite impossible and only the microscopic observation of the specimen can show the causative agent . Surgical options are reported, stressing the need for an adequate period of antimicrobial therapyPIP: In September 1993 a 43-year-old female patient with cancer underwent left mastectomy followed by immediate reconstruction . 6 days passed without problems, but then she presented at the emergency ward with abundant exudation of serous material from the cicatrices . Microbiological test showed evidence of Staphylococcus epidermitis . Drainage of the skin and smooth muscle was performed and the secretion was immediately reduced and seemed to disappear in a short time . In the next 3 days fever arose accompanied by abdominal pain . Blood test showed leucocytosis (24,500 GB), increase of the suppressor lymphocytes (CD8) and the reduction of CD4/CD8 ratio . Abdominal-pelvic echogram showed evidence of an enlarged right adnexum as well as that of the homolateral tube, but no discharge of fluid in the pelvic cavity . Gynecological examination in this patient, who had worn an IUD two months prior, excluded lesions in the portio or vagina and the vaginal flora did not show fungi or parasites . Diagnostic laparoscopy followed, which demonstrated in the pelvic cavity a large para-uterine tumefaction . The pelvic organs were adhering to the parietal layer of the peritoneum and in the whole peritoneal cavity, including the interhepatic-diaphragmatic space, fibrin plaque and pus was observed . Laparotomy was performed, which confirmed a parauterine mass and a tubo-ovarian complex with numerous recesses containing fetid, grayish pus . Complete right adnexectomy was carried out with abundant lavage and multiple drainage of the peritoneal cavity . Subsequently, the abdominal situation improved, but a new examination of drained liquid showed the presence of cutaneous bacterial flora but no fungi or parasites . Ovarian actinomycotic abscess with acute peritonitis and salpingitis was demonstrated . Subsequent antibiotic therapy consisted of piperacilline for 15 days, and 4 months after the episode the patient was well without return of the foci of infection .

Diagn Microbiol Infect Dis, 1996 Sep, 26(1), 43 - 5
The utility of non-beta-lactam antimicrobial MICs as markers to distinguish oxacillin-resistant from oxacillin-susceptible strains of Staphylococcus epidermidis; Fass RJ et al.; Among 6,068 strains of Staphylococcus epidermidis, 75.5% were oxacillin-resistant . Oxacillin-susceptible strains were more frequently susceptible to erythromycin, clindamycin, ciprofloxacin, trimethoprim/sulfamethoxazole, gentamicin, and tetracycline than oxacillin-resistant strains . With the exception of erythromycin, non-beta-lactam MICs were less discriminatory for identifying oxacillin-resistant strains with oxacillin MICs < or = 2 micrograms/ml than for those with oxacillin MICs > or = 4 micrograms/ml.

ASAIO J, 1996 Sep-Oct, 42(5), M881 - 4
Evidence that bacteria prefer to adhere to thrombus; Bos HM et al.; This study was undertaken to investigate the possible association between thrombosis and infection using an in vitro test model in which fresh bovine blood was recirculated through test conduits (3.5 mm inner diameter) containing stent-like devices . Anticoagulation was adjusted so that the recirculating blood deposited thrombi on the stent to cause gradual occlusion, thus impeding the flow . Four stent-like devices were placed in separate conduits in each experiment, and blood was recirculated with the help of pneumatically driven ventricles . Flow through these conduits was monitored by ultrasonic flow detection . To quantitate bacterial interaction with thrombi, Staphylococcus epidermidis (15E10(9)) was labeled with 111Indium-oxine and added to the blood . Experiments lasted until the flow in the test conduits dropped to 10% of the starting flow . During this recirculation, as flow gradually decreased, one stent was taken out when flow was still at 100%, the second at 75%, the third at 50%, and the fourth at 10% of the starting flow . The number of bacteria associated with the thrombus was measured by gamma counting . The following observations were made: 1) the amount of thrombus increased with time in all experiments (this was confirmed in separate experiments by using autologous 111Indium labeled platelets); 2) bacterial adhesion showed a concomitant increase as thrombus size increased (this was confirmed by using 111Indium labeled bacteria), and 3) bacterial incorporation into the thrombus occurred regardless of whether they were viable or pretreated with the antibiotic rifampin . These observations suggest that as thrombi develop, they may preferentially attract micro-organisms . This suggests that devices with adherent thrombi may have greater susceptibility for infection.

ASAIO J, 1996 Sep-Oct, 42(5), M645 - 8
Immunoadsorption with protein A in humoral rejection of kidney transplants; Pretagostini R et al.; The presence of alloantibodies may play a role in accelerated or acute humoral rejection . Different therapeutic strategies based on a removal of anti donor antibodies and prevention of their resynthesis have been used in the management of transplant rejection episodes . Immunoadsorption with staphylococcal protein A, a method to selectively remove immunoglobulin G, may represent a new treatment to reverse humoral rejection in kidney transplantation . From 1991 to January 1996, such a method was used in 23 patients in whom an acute humoral rejection developed over a mean period of 14.1 +/- 9.5 days after operation . Twenty-two patients had been transplanted from living donors and one from a cadaveric donor . The ages ranged from 23 to 58 years (mean, 34 +/- 10 years) . All transplants were performed according to a negative direct crossmatch . Basic immunosuppression included cyclosporine, steroids, azathioprine, and antilymphocyte globulin or monoclonal antibodies (OKT3) . Rejection was diagnosed on the basis of hematochemical tests, Doppler ultrasonography, and kidney biopsy . Only steroid and monoclonal and polyclonal antibody resistant rejections with > 165% positive direct crossmatches against the donor were treated with Protein A immunoabsorption . The procedure used is based on the treatment of 2-3 plasma volumes for the first 2 days and then every other day until a negative crossmatch is obtained, together with improvement in clinical status (mean treatments, 7.3 +/- 4.5 {range, 4-23}; mean duration of treatment, 12.3 +/- 10.2 days {range, 3-44}) . From the start of treatment, azathioprine is replaced by cyclophosphamide at a dose of 1-2 mg/kg/day . During treatment, a remarkable fall in immunoglobulin G levels is achieved on the first day, whereas immunoglobulin M titers remain constant, with a slight decrease in serum albumin . Immediately after treatment, a negative crossmatch was found in 22 (95.6%) of 23 patients . In six patients (26%), graft function did not recover, and one patient (4.3%) died . Preliminary results show that immunoabsorption with staphylococcal protein A may be an effective support in the treatment of humoral acute rejection, particularly when it is performed as soon as an early diagnosis of humoral rejection is made . In fact, such treatment has a highly selective adsorption, allows treatment of large volumes of plasma, and can achieve a rapid decrease in the titer of circulating immunoglobulins.

Toxicol Pathol, 1996 Sep-Oct, 24(5), 619 - 26
Potentiation of inhaled staphylococcal enterotoxin B-induced toxicity by lipopolysaccharide in mice; LeClaire RD et al.; Nonhuman primates are the established model for evaluating toxic responses to staphylococcal enterotoxins (SEs), as they react similarly to humans . Rodents are generally considered unresponsive to SEs . Binding affinities and T-cell reactivity suggest that SE binds more efficiently to primate major histocompatability complex class II receptors than to mouse receptors . We investigated the potentiation of staphylococcal enterotoxin B (SEB) inhalation toxicity by lipopolysaccharide (LPS) in BALB/c mice . Lethality occurred only when SEB was potentiated by LPS . Neither SEB nor LPS produced lethal effects alone . Temporal responses of interleukin 1 alpha, tumor necrosis factor alpha, interleukin 2, and interferon-gamma evoked by inhaled SEB were enhanced by LPS . By 24 hr after intoxication, serum cytokines decreased to baseline levels, and consistent pulmonary perivascular leukocytic infiltrates were evident histologically . Histologic lesions induced by inhalation exposure to SEB by mice, with or without potentiation by LPS, were similar to those in the rhesus monkey . Predominant pulmonary lesions included severe, diffuse interstitial and alveolar pulmonary edema, leukocytic infiltrates, mild perivascular edema, and alveolar fibrin deposition . Although the mechanism of aerosolized SEB-induced toxicity has not been completely resolved, similarities in histologic lesions, cytokine responses, and acute dose-response suggest the LPS-potentiated mouse model may be a credible alternative to the nonhuman primate model.

J Perinatol, 1996 Sep-Oct, 16(5), 331 - 5
Vancomycin cerebrospinal fluid concentrations after intravenous administration in premature infants; Reiter PD et al.; OBJECTIVE: Staphylococcal species are the most common cause of nosocomial infections in the neonate . Because of staphylococcal resistance patterns, vancomycin has become the drug of choice for treatment . Although the blood stream is the usual site of infection, premature infants are at increased risk for the development of meningitis . The aim of this study was to determine vancomycin cerebrospinal fluid (CSF) concentration and penetration following intravenous (IV) administration in critically ill premature infants . STUDY DESIGN: A multiple-dose, open-label, case series was performed at a level III neonatal intensive care unit in a university teaching hospital . Three critically ill premature infants, 26 to 31 weeks of gestation requiring a course of IV vancomycin for suspected or proved sepsis were studied . Vancomycin was administered intravenously at 20 mg/kg, every 18 to 24 hours over 60 minutes . Serum and CSF vancomycin concentrations were obtained and pharmacokinetic analysis and CSF penetration was calculated . RESULTS: Serum vancomycin pharmacokinetics were consistent with those previously reported . CSF vancomycin concentrations ranged from 2.2 to 5.6 micrograms/ml and the calculated vancomycin CSF penetration ranged from 26% to 68% . CONCLUSIONS: CSF penetration of vancomycin after IV administration was much higher than that reported in older infants and children . This higher penetration may improve clinical outcomes in neonates with central nervous system infections . These data should be encouraging to clinicians who choose to use IV vancomycin for neonatal meningitis.

Perit Dial Int, 1996 Sep-Oct, 16(5), 505 - 10
Continuous peritoneal dialysis-associated peritonitis of nosocomial origin; Troidle L et al.; OBJECTIVE: To describe our experience with nosocomial continuous peritoneal dialysis (CPD)-associated peritonitis focusing on the incidence, possible risk factors, spectrum of organisms, and outcome . DESIGN: Retrospective review of the medical records of our CPD patients admitted to an acute-care hospital between November, 1993 and December, 1994 . SETTING: University-associated acute-care hospitals in New Haven, Connecticut . PATIENTS: One hundred and eighty-eight patients maintained on CPD therapy and admitted to an acute-care hospital . RESULTS: Nineteen patients (5%) developing nosocomial peritonitis (NP) were identified from the 408 admissions occurring during the study period . Patients developing NP were older than the hospitalized CPD patients not developing NP (65.5 +/- 14.6 vs 58.4 +/- 14.7 years, p < 0.05) . Comorbid diseases including diabetes, peripheral vascular disease, gastrointestinal disease, cardiovascular disease, and human immunodeficiency virus seropositivity were not more common in the patients developing NP . Patients developing NP were hospitalized significantly longer than the CPD patients not developing NP (39.5 +/- 46.5 days vs 12.7 +/- 12.4 days, p < 0.001) . The mean serum albumin was lower in the NP patients than in the CPD patients not developing NP (2.35 +/- 0.52 g/dL vs 3.02 +/- 0.60 g/L, p < 0.001) . Antecedent antibiotic use and performance of invasive procedures were noted in 89% and 68% of the patients developing NP, respectively . Staphylococcal species, enterococcal species, and gram-negative organisms accounted for 26%, 21%, and 53% of the episodes of NP, respectively . Furthermore, two strains of Enterococcus resistant to vancomycin were cultured . Eight patients developing NP expired, 8 patients continued CPD therapy, 2 patients transferred to hemodialysis, and one patient recovered renal function . CONCLUSION: We conclude that NP is uncommon . Increased age, increased length of hospital stay, and hypoalbuminemia may predispose patients to the development of NP . Further studies with case controls should help to clarify whether antecedent antibiotics or prior performance of invasive procedures predispose patients to the development of nosocomial peritonitis . The spectrum of organisms accounting for NP is different than the spectrum of organisms causing community-acquired CPD-associated peritonitis . Some of these organisms may be resistant to standard antibiotic therapies . Patients developing NP do poorly, with 42% expiring while being treated for NP.

Clin Exp Rheumatol, 1996 Sep-Oct, 14(5), 507 - 12
Experimental septic arthritis in rabbits treated by a combination of antibiotic and steroid drugs; Wysenbeek AJ et al.; OBJECTIVES: Intraarticular steroid injection is traditionally contraindicated during acute septic arthritis . However, there is abundant evidence which proves that the damage to the joint is not only due to the direct effect of bacteria, but also to the local protective mechanisms evoked by the organism . There is, therefore, theoretical justification for a combined therapy of systemic antibiotics and intraarticular corticostertoids in septic arthritis . METHODS: Experimental arthritis was induced by the intraarticular injection of Staphylococcus epidermidis in rabbits . The experimental scheme included three groups of animals: animals that were infected but not treated (group 1); animals treated with systemic antibiotics (group 2); and animals treated with systemic antibiotics and intraarticular steroids (group 3) . Nine days later the animals were sacrificed and joint histopathological-histochemical indices were calculated . RESULTS: Animals from groups 2 and 3 had a smaller pannus, reduced proteoglycan loss, no loss of cartilage height and diminished synovial inflammation in comparison to the animals from group 1 . The animals from groups 2 and 3 were identical in terms of cartilage cellularity, surface erosion, chondrocyte cloning, pannus formation and proteoglycan loss . Synovial inflammation appeared to be less pronounced in group 3 animals when compared to animals of group 2 . CONCLUSION: Concomitant antibiotic-steroid treatment of septic arthritis seems to be harmless in this experimental setting.

Optom Vis Sci, 1996 Sep, 73(9), 590 - 4
Factors affecting Staphylococcus epidermidis adhesion to contact lenses; Fleiszig SM et al.; BACKGROUND: Staphylococcus epidermidis is a major causative agent of infectious keratitis associated with contact lens wear . Adhesion of this bacterium to contact lenses may contribute to the pathogenesis of infection and could be influenced by lens surface properties, packaging/storage solutions, and vary among different strains according to the level or type of adhesins expressed . METHODS: Adhesion of six clinical isolates of S . epidermidis to three different contact lens materials was tested . Adhesion assays were performed on lenses immediately after removal from their packages, and also after lenses were soaked in sterile phosphate buffered saline (PBS) for 7 days to dilute the packaging solution . RESULTS: For lenses tested immediately upon removal from their packaging, adhesion to polymacon (in PBS with 0.1% polyvinyl alcohol) was significantly greater than to etafilcon A (in borate buffered saline) and vifilcon A (in PBS) . After soaking, adhesion to polymacon lenses was significantly less than to the other lens materials . This pattern was consistent for all strains, although major differences in baseline adhesion levels existed between strains, with exopolysaccharide (slime)-positive bacteria being more adherent to lenses . CONCLUSIONS: Properties of contact lens materials were not the sole determinant of viable S . epidermidis adhesion to lenses . Strain variability, including levels of exopolysaccharide expression, and the solution used for lens immersion also influenced adhesion.

Protein Sci, 1996 Sep, 5(9), 1942 - 6
A fragment of staphylococcal nuclease with an OB-fold structure shows hydrogen-exchange protection factors in the range reported for "molten globules"; Alexandrescu AT et al.; Hydrogen-exchange rates for an OB-fold subdomain fragment of staphylococcal nuclease have been measured at pH 4.7 and 4 degrees C, conditions close to the minimum of acid/base catalyzed exchange . The strongest protection from solvent exchange is observed for residues from a five-stranded beta-barrel in the NMR structure of the protein . Protection factors, calculated from the experimental hydrogen-exchange rates, range between 1 and 190 . Similarly small protection factors have in many cases been attributed to "molten globule" conformations that are supposed to lack a specific tertiary structure . The present results suggest that marginal protection from solvent exchange does not exclude well-defined structure.

Protein Sci, 1996 Sep, 5(9), 1898 - 906
A dynamic bundle of four adjacent hydrophobic segments in the denatured state of staphylococcal nuclease; Wang Y et al.; In an earlier study of the denatured state of staphylococcal nuclease (Wang Y, Shortle D, 1995, Biochemistry 34:15895-15905), we reported evidence of a three-strand antiparallel beta sheet that persists at high urea concentrations and is stabilized by a local "non-native" interaction with four large hydrophobic residues . Because the amide proton resonances for all of the involved residues are severely broadened, this unusual structure is not amenable to conventional NMR analysis and must be studied by indirect methods . In this report, we present data that confirm the important role of interactions involving four hydrophobic residues (Leu 36, Leu 37, Leu 38, and Val 39) in stabilizing the structure formed by the chain segments corresponding to beta 1-beta 2-beta 3-h, interactions that are not present in the native state . Glycine substitutions for each of these large hydrophobic residues destabilizes or disrupts this beta structure, as assessed by HN line sharpening and changes in the CD spectrum . The 13C resonances of the carbonyl carbon for several of the residues in this structure indicate conformational dynamics that respond in a complex way to addition of urea or changes in sequence . Studies of hydrogen exchange kinetics in a closely related variant of staphylococcal nuclease demonstrate the absence of the stable hydrogen bonding between the strands expected for a native-like three-strand beta sheet . Instead, the data are more consistent with the three beta strand segments plus the four adjacent hydrophobic residues forming a dynamic, aligned array or bundle held together by hydrophobic interactions.

J Hosp Infect, 1996 Sep, 34(1), 31 - 42
A comparison of methods to determine whether clinical isolates of Staphylococcus epidermidis from the same patient are related; Hedin G; Staphylococcus epidermidis is a major cause of hospital-acquired infections but also part of the normal skin flora . A common clinical question is whether repeated isolation of S . epidermidis from one patient represents the same strain; because if different strains are isolated, they are often thought to be contaminants . In this study, different typing methods were compared to answer this question . Twenty isolates of S . epidermidis from five different patients were investigated . The isolates from each patient had identical or very similar antibiograms, and were recovered on different occasions . Typing was performed by antibiogram, biotype, slime production, plasmid profile, and pulsed-field gel electrophoresis (PFGE) banding pattern of SmaI digests of chromosomal DNA . In addition, the level of resistance to methicillin was determined by growth curves in broth containing methicillin for a series of different inocula for each isolate . The results showed that the isolates from each patient belonged to the same clone, but examples of instabilities in their antibiograms, plasmid profiles, as well as their PFGE banding patterns were seen . A change in the level of methicilli, resistance was observed in one strain; otherwise this characteristic was found to be strain-specific and stable in vivo . It was concluded that in combination with biotyping and antibiotic resistance testing the level of resistance to methicillin could be used as an aid to distinguish between two or more clinical isolates of S . epidermidis from the same patient.

Int J Food Microbiol, 1996 Sep, 32(1-2), 59 - 71
The combined effects of environmental conditions on lipolysis of pork fat by lipases of the meat starter culture organisms Staphylococcus xylosus and Debaryomyces hansenii; Sorensen BB et al.; The effects of environmental conditions on lipolysis by cell-free extracts from the meat starter culture organisms Staphylococcus xylosus and Debaryomyces hansenii were studied using pork fat emulsions as model systems . For the individual effects of temperature and pH it was found that the optimal conditions for the lipolysis by S . xylosus lipase were 37 degrees C and pH 7.0, and 37 degrees C and pH 6.5 for the lipolysis by D . hansenii lipase . For the combined effects of conditions relevant to meat fermentation, i.e . 10-30 degrees C, pH 4.7-6.0, 2.5-7.5% (w/v) NaCl and incubation times of 2-6 days, the empirical models indicated that temperature, pH and incubation time had important effects on total lipolysis whereas NaCl concentration had little effect . For both cultures lipolysis was strongly inhibited at conditions of meat fermentation compared to optimal conditions . For any set of the conditions which were examined the total lipolysis caused by D . hansenii lipase was lower than that caused by S . xylosus lipase.

Antimicrob Agents Chemother, 1996 Sep, 40(9), 2224 - 5
Macrolide-lincosamide-streptogramin B resistance in Staphylococcus lentus results from the integration of part of a transposon into a small plasmid; Werckenthin C et al.; The 8.0-kb macrolide-lincosamide-streptogramin B resistance plasmid pSES20 from Staphylococcus lentus harbored part of a Tn917-like transposon including the left terminal repeat, a gene almost identical to ermB, and its regulatory region, as well as the internal direct repeat . Homology between pSES20 and Tn917 ended at a sequence closely related to those of the resolution sites of Tn917 and Tn552 and staphylococcal recombination sites.

Chemotherapy, 1996 Sep-Oct, 42(5), 384 - 90
Antimicrobial prophylaxis with ceftriaxone in neurosurgical procedures . A prospective study of 100 patients undergoing shunt operations; Arnaboldi L; Shunt infection is a major complication of shunt implantation, with Staphylococcus epidermidis found in almost 45% of infected shunts . This pathogen produces an extracellular slime that enables it to adhere to implantable devices and resist antibiotic therapy . Antimicrobial prophylaxis can prevent slime production . In this paper we report the results of a prospective study involving 100 shunt operations . The objective was to evaluate the efficacy of a single preoperative dose of ceftriaxone (2 g, i.v.) in preventing shunt infection . Ceftriaxone was chosen for its pharmacokinetic properties . No shunt infection was observed over a 4-year follow-up period . On the basis of these results we recommend prophylaxis with ceftriaxone as a safe and effective way of preventing shunt infection . In addition, one-shot prophylaxis with ceftriaxone is more cost-effective than multiple-dose antibiotic regimens.

Hum Immunol, 1996 Sep 1, 49(2), 113 - 21
Human CD4-reactive antibodies from SLE patients induce reversible inhibition of polyclonal T lymphocyte proliferation; Lenert G et al.; We report on isolation of human polyclonal CD4-reactive antibodies of IgM and/or IgG isotypes from several SLE patients . These antibodies bound specifically to CD4-expressing cell lines and to rCD4 in ELISA and immunoblots . Saturation of CD4-binding sites occurred at antibody concentrations between 5 and 15 micrograms/ml . Anti-CD4 antibodies, in a dose-dependent manner, suppressed the proliferative responses of human peripheral blood mononuclear cells (PBMC) to superantigens (Staphylococcal enterotoxins A and B), anti-CD3 antibodies, and mitogens (PWM and Con A, but not PHA) . They could also inhibit the proliferation of highly purified human T cells induced by immobilized anti-CD3 antibodies . To promote their effects on T cells, human anti-CD4 antibodies had to be present at lymphocyte cultures before or at the time of priming . There was no significant inhibition when antibodies were added more than 24 h following T cell activation . Substantial evidence that the immunosuppression induced by anti-CD4 antibodies was due to their direct effect on T cells was obtained . Down-regulatory effect of anti-CD4 antibodies could be significantly reversed by addition of exogenous IL-2 and by preincubation with soluble recombinant (r)CD4 . Interestingly, at least one affinity-purified anti-CD4 antibody could costimulate the T cell proliferation induced by superantigens or anti-CD3 antibodies, especially when used at subsaturating concentrations (1-4 micrograms/ml) and when added subsequently to the initiation of cultures.

J AOAC Int, 1996 Sep-Oct, 79(5), 1095 - 101
Immunoenzymatic detection of staphylococcal enterotoxins: international interlaboratory study; Lapeyre C et al.; An international interlaboratory study was performed by 13 laboratories to validate a commercially available, rapid enzyme immunoassay for detection of staphylococcal enterotoxins A, B, C, D, and E in foods . The 5 enterotoxin serotypes were detected at a level of 0.5 ng/g in mushrooms and ravioli, 0.8 ng/g in meat, 1 ng/mL in milk, and 1.5 ng/g in raw milk cheese when these foods were artificially contaminated with enterotoxin A . Enterotoxins A, B, C, D, or E were also detected in culture supernatants with no protein A interference when normal rabbit serum was used . This method was validated by the French Normalization Agency for the identification of staphylococcal enterotoxins in foods and culture fluids.

Eur J Immunol, 1996 Sep, 26(9), 2075 - 80
Synergistic effect between CD40 and class II signals overcome the requirement for class II dimerization in superantigen-induced cytokine gene expression; Mehindate K et al.; Although staphylococcal enterotoxin A (SEA), B (SEB), and toxic shock syndrome toxin 1 (TSST-1) bind to major histocompatibility complex (MHC) class II molecules, they differ in their mode of binding . Signaling induced by these toxins via MHC class II molecules seems to be largely mediated by their mode of interaction . In the present study, we have demonstrated that contrary to SEA, stimulation of the human monocytic cell line THP-1 with SEB or TSST-1 failed to induce interleukin-1 beta or tumor necrosis factor-alpha gene expression . Treatment of THP-1 cells with interferon-gamma increased the level of MHC class II expression but did not enhance the SEB and TSST-1 response . However, cross-linking of SEB or TSST-1 bound to MHC class II molecules with specific antibodies leads to cytokine gene expression, indicating that dimerization of class II molecules is a requirement for this superantigen-induced response . The presence of anti-CD40 antibodies in the course of SEB or TSST-1 stimulation overcomes this requirement, indicating that certain signal(s) induced via CD40 molecules can replace those induced by dimerization of class II molecules . Pretreatment with anti-lymphocyte functional antigen-1 (LFA-1) antibodies completely inhibited SEA-induced response as well as that induced by SEB or TSST-1 in the presence of CD40 antibodies, supporting the involvement of LFA-1 intercellular adhesion molecule system in these responses . The entirety of these results demonstrate clearly that dimerization of class II molecules is a prerequisite for superantigen-induced T cell-independent cytokine gene expression which can be replaced by signaling via CD40 in an LFA-1-dependent system.

Arthritis Rheum, 1996 Sep, 39(9), 1499 - 506
Increased responsiveness of rheumatoid factor-producing B cells in seronegative and seropositive rheumatoid arthritis; He X et al.; OBJECTIVE: To compare the frequencies and responsiveness of rheumatoid factor (RF)-producing B cells in the peripheral blood of patients with seronegative and seropositive rheumatoid arthritis (RA) . METHODS: Frequencies of IgM+, IgG+, and RF+ B cells were determined by limiting-dilution analysis of purified peripheral blood B cells from 6 patients with seropositive RA, 8 patients with seronegative RA, and 7 normal controls . B cell help was provided by cloned T helper cells, which were stimulated by either anti-CD3 or the bacterial superantigen staphylococcal enterotoxin D (SED) . IgM and IgG antibodies and RF in culture supernatants were detected by enzyme-linked immunosorbent assay . RESULTS: In the presence of anti-CD3-stimulated T helper cells, 2-10% of B cells from normal individuals secreted IgM and IgG antibodies . The frequency of RF+ B cells was low and ranged from 1:182 to 1:885 (RF+: IgM+) B cells . In patients with seropositive RA, the numbers of Ig-producing B cells were reduced by a factor of 2, while the fraction of RF+ B cell precursors was expanded by more than 50-fold (7-20% of IgM+ B cells; P = 0.004) . Patients with seronegative RA had higher frequencies of RF-producing B cells (1.5-6% of IgM+ B cells) than normal individuals (P = 0.002), but not to the same extent as seropositive patients (P = 0.002) . Stimulation of B cells using SED preferentially induced RF+ B cells in normal controls and in patients with seronegative and seropositive RA . CONCLUSION: B cell precursors with the potential to secrete RF were detectable in high frequencies in normal individuals and in patients with seropositive and seronegative RA . In all donors, these B cells could be stimulated with the bacterial superantigen SED . In normal individuals, RF+ B cells remained nonresponsive to help provided by anti-CD3-activated T cells, but were responsive in RA patients . Seronegative and seropositive RA form a continuous spectrum of disease, with a higher number of RF-secreting B cells in the seropositive patients.

Immunity, 1996 Sep, 5(3), 275 - 83
The involvement of an ATP-gated ion channel, P(2X1), in thymocyte apoptosis; Chvatchko Y et al.; In the immune system, apoptosis is involved in intrathymic elimination of self-reactive thymocytes and in peripheral T cell tolerance to exogenous antigens . Here, we describe the role in T cell apoptosis of P(2x1), a nonselective cation channel activated by ATP . P(2X1) molecules are up-regulated in thymocytes during dexamethasone-induced apoptosis, and antagonists to these receptors protect thymocytes from cell death . Moreover, P(2X1) mRNA and protein levels increase in thymocytes induced to die in vivo by the superantigen staphylococcal enterotoxin B . In contrast, T cells undergoing apoptosis in the periphery do not express P(2X1) . The demonstration that P(2X1) ion channels play a role in the apoptosis of thymocytes but not peripheral T cells illustrates a novel mechanism contributing to thymocyte cell death and opens new possibilities for investigating clonal deletion in the thymus.

Am J Kidney Dis, 1996 Sep, 28(3), 428 - 36
Risk factors for peritonitis in long-term peritoneal dialysis: the Network 9 peritonitis and catheter survival studies . Academic Subcommittee of the Steering Committee of the Network 9 Peritonitis and Catheter Survival Studies; Golper TA et al.; To determine factors involved in peritoneal dialysis-associated peritonitis and catheter loss, all point prevalent peritoneal dialysis patients in Health Care Finance Administration (HCFA) end-stage renal disease (ESRD) Network 9 were followed throughout 1991 for peritonitis events and throughout 1991 to 1992 for catheter survival . Data were collected by questionnaires compiled by the dialysis facility and validated by network staff . Peritonitis was reported 1,168 times in 729 of the 1,930 patients . By gamma-Poisson regression, a significantly increased risk for peritonitis was observed for patients with previous peritonitis, black race, and those dialyzing with standard connectors or cyclers compared with disconnect systems . Decreased risks were observed for patients with longer ESRD experience and when prophylactic antibiotics were administered before catheter insertion . Postinsertion leakage, diabetes, visual problems, previous or current immunosuppression, and physical activity were not risk factors . Infection of any kind caused the removal of 68% of the 414 catheters lost . Patients with downward-directed tunnels were less likely to experience concomitant exit site/tunnel infections associated with peritonitis . Peritonitis episodes with Staphylococcus epidermidis-like organisms were more likely to resolve with a single course of antibiotics . Perhaps because of their higher infection rate, blacks were more likely than whites to use a disconnect system . In general, the outcome of peritonitis in blacks was similar to that in whites, except that blacks were less likely to be hospitalized and were less likely to die.

Scand J Immunol, 1996 Sep, 44(3), 252 - 60
Monocyte-dependent costimulatory effect of TGF- beta 1 on rat T-cell activation; Schiott A et al.; TGF- beta 1 is known to have suppressive effects on both T-cell proliferation and effector functions, but costimulatory effects have also been reported . In the present investigation the effect of TGF- beta 1 is studied in vitro on T-cell proliferative responses of rat spleen cells and of lymph node cells to alloantigens (MLR), the superantigen Staphylococcal enterotoxin A (SEA) or IL-2 . Without addition of TGF- beta 1, adherent, freshly isolated rat spleen monocytes have a suppressive effect on T-cell activation, which upon addition of TGF- beta 1 is reversed to a strong costimulatory effect . The costimulatory effect of TGF- beta 1 is shown to be entirely dependent on the presence of fresh monocytes . Costimulation is demonstrated when TGF- beta 1 is added to spleen cells at the start of the in vitro assays but not when added more than 24 h after the start . Costimulation is not demonstrable when TGF- beta 1 is added to lymph node cells alone but is readily detectable after admixture of freshly isolated spleen monocytes to the lymph node cells . TGF- beta 1 added at the end of culture induces suppression of T-cell activation irrespective of the presence or absence of monocytes . When TGF- beta 1 is added both at the start of an MLC and again after 4 days, the costimulatory effect is maintained, although somewhat moderated . The costimulatory effect of TGF- beta 1 is demonstrated as an increase of the T blast cell population of both CD4+ IL-2R+ and CD8+ IL-2R+ T-cell subsets, whereas the suppressive effect of TGF-beta 1 is shown as reduction of the same parameters.

Scand J Immunol, 1996 Sep, 44(3), 229 - 38
Requirement of CD80 and CD86 molecules for antigen presentation by eosinophils; Tamura N et al.; The authors analysed the antigen-presenting ability of eosinophils purified from peritoneal exudate cells of interleukin-5 (IL-5) transgenic mice . The granulocyte-macrophage colony-stimulating factor (GM-CSF)-treated eosinophils induced proliferative responses of primed lymph node T cells and thymus T cells to staphylococcal enterotoxin B (SEB), while untreated eosinophils induced little or no response . GM-CSF-treated eosinophils also induced proliferation of ovalbumin (OVA)-primed lymph node T cells to OVA . Although untreated eosinophils expressed no MHC class II molecule on the surface the eosinophils could be induced to express major histocompatibility complex (MHC) class II molecules when treated with GM-CSF . In the present study, anti-I-Ak monoclonal antibodies (MoAbs) strongly inhibited proliferation of thymus T cells and proliferation of OVA-primed lymph node T cells in response to OVA, but weakly inhibited proliferation of primed T cells in response to SEB . Furthermore, CD80 (B7-1) and CD86 (B7-2) were expressed on the surfaces of untreated eosinophils . The expression of those two molecules on the eosinophils was increased by incubation with GM-CSF . Moreover, anti-CD80 or anti-CD86 MoAbs blocked proliferative responses of primed lymph node T cells and thymus T cells to SEB, and also blocked responses of primed lymph node T cells to OVA . Thus, CD80 and CD86 play an important role in stimulation of T cells by eosinophils.

J Immunol, 1996 Sep 1, 157(5), 1935 - 43
Switching on of the proliferation or apoptosis of activated human T lymphocytes by IFN-gamma is correlated with the differential expression of the alpha- and beta-chains of its receptor; Novelli F et al.; To find out how physiologically secreted IFN-gamma controls either the proliferation or the apoptosis of human T lymphocytes, the kinetics of expression of the alpha- and beta-chains of its receptor (IFN-gamma R) were sequentially followed on T lymphocytes first activated with PHA and then cultured in the presence of IL-2, and related to the kinetics of expression of Fas, Bcl-2, and IL-2R p55 chain . Both IFN-gamma R chains were poorly expressed on the membrane of resting T lymphocytes . Following their stimulation with PHA, IFN-gamma R alpha but not IFN gamma R beta-chain up-modulated before T lymphocyte entry into the S phase, and then IFN-gamma R alpha down-modulated when they passed through the S and G2/M . The ensuing proliferative response was inhibited by an anti-IFN-gamma R alpha mAb that impeded the binding of IFN-gamma . When PHA-activated T lymphoblasts were cultured for 16 days with IL-2, IFN-gamma R alpha expression increased, whereas that of the beta-chain remained barely detectable . Fas and Bcl-2 were both highly expressed . When these T lymphoblasts were restimulated by PHA, OKT3, or Staphylococcus enterotoxin beta-pokeweed mitogen, both chains up-modulated and most cells underwent apoptosis in a way apparently independent of Bcl-2, but not of Fas . This apoptosis, too, was prevented by the anti-IFN-gamma R alpha mAb . Physiologically secreted IFN-gamma is thus involved in the activation of resting T lymphocytes and in the apoptosis of reactivated lymphoblasts . However, high expression of IFN-gamma R beta took place when IFN-gamma induced apoptosis, but not when it induced proliferation . In conclusion, a correlation exists between differential expression of the IFN-gamma R beta-chain and the delivery by IFN-gamma of proliferative or apoptotic signals.

Infect Immun, 1996 Sep, 64(9), 3893 - 6
The hemagglutinin of Staphylococcus saprophyticus is a major adhesin for uroepithelial cells; Meyer HG et al.; The 160-kDa hemagglutinin of Staphylococcus saprophyticus also serves as a fibronectin-binding protein, and the two activities may be present on different parts of the molecule . Bacteria expressing the 160-kDa hemagglutinin bound in large numbers to histological sections of human ureters, whereas nonhemagglutinating bacteria did not bind . Binding was decreased by an antiserum to the 160-kDa protein and by a preparation of sheep erythrocyte membranes . Fibronectin had no effect . We therefore conclude that binding of S . saprophyticus to uroepithelial cells is mediated by the hemagglutinating activity of the 160-kDa surface protein.

J Urol, 1996 Sep, 156(3), 991 - 4
A randomized prospective comparison of antibiotic tissue levels in the corpora cavernosa of patients undergoing penile prosthesis implantation using gentamicin plus cefazolin versus an oral fluoroquinolone for prophylaxis; Schwartz BF et al.; PURPOSE: We performed a prospective randomized trial comparing the efficacy, safety and cost of parenteral antibiotics and oral fluoroquinolones for prophylaxis in penile prosthesis surgery . MATERIALS AND METHODS: We prospectively randomized 20 consecutive patients undergoing penile prosthesis surgery to receive ofloxacin orally or gentamicin and cefazolin parenterally followed by cephradine orally . Intraoperatively corpora cavernosa tissue and simultaneous peripheral serum samples were evaluated for antibiotic levels . Median followup was 16 months (range 8 to 21, mean 15.35) . RESULTS: There were no implant losses or reoperations and complications were comparable in the 2 groups . The difference in mean serum-to-tissue ratios of ofloxacin versus the combination of cefazolin and gentamicin was statistically significant (p < 0.03) . The minimum inhibitory concentrations of ofloxacin met or exceeded those of the 2 most common offending organisms, Staphylococcus epidermidis and Escherichia coli, in 80% of patients, which was comparable to the results of the parenteral regimen . Cost savings of the medications alone were more than $250,000 in the ofloxacin group . By eliminating a hospital stay of the 25,000 cases of penile prosthesis placement in the United States yearly a total cost savings of more than $36 million would be realized . CONCLUSIONS: When oral ofloxacin is given for prophylaxis in penile implant surgery, the procedure may be performed on an outpatient basis and health care dollars are saved.

J Biol Chem, 1996 Aug 30, 271(35), 21075 - 80
Limited proteolysis of rat phosphatidylinositol transfer protein by trypsin cleaves the C terminus, enhances binding to lipid vesicles, and reduces phospholipid transfer activity; Tremblay JM et al.; Rat phosphatidylinositol transfer protein (PITP) is a 32-kDa protein of 271 amino acids that transfers phosphatidylinositol and phosphatidylcholine between membranes . The alpha isoform of rat PITP was expressed in Escherichia coli and purified in high yields . The purified protein contained 1 mol of phosphatidylglycerol and had a transfer activity for phosphatidylinositol and phosphatidylcholine equal to or greater than that of PITP purified from mammalian brain . Limited protease digestion was used to further define structure, activity, and function relationships in PITP . PITP alone is relatively resistant to digestion by chymotrypsin, trypsin, and Staphylococcus V8 protease but is readily cleaved by subtilisin . Phospholipid vesicles containing phosphatidic acid enhance susceptibility to digestion by all four proteases . In the presence of vesicles, PITP, which migrates as a 36-kDa protein in SDS-polyacrylamide gel electrophoresis, is cleaved rapidly by trypsin to a form that appears to be 2-3 kDa smaller than the native form . The tryptic fragment retains partial phospholipid transfer activity and shows an enhanced affinity for phospholipid vesicles containing phosphatidic acid . Analysis of the tryptic digestion products by immunoblotting, N-terminal sequencing, and electrospray mass spectrometry showed that trypsin cleaves the C terminus of PITP at Arg253 and Arg259 . Thus, removal of the C terminus enhances the affinity of PITP for vesicles and results in a dimunition of transfer activity . Overall, the data show that PITP undergoes conformation changes and that the C terminus becomes more accessible to trypsin when bound to vesicles . Hence, the C terminus is not an essential component of the membrane binding site and may be located distal to it.

Cell Immunol, 1996 Aug 25, 172(1), 135 - 8
Anti-HLA class I antibody inhibits Staphylococcus enterotoxin A (SEA)-induced proliferation of human PBMC; Baskar P et al.; The antigen-presenting role of major histocompatibility complex (MHC) Class I molecules in the activation of appropriately restricted T cells is well documented . Now growing evidence indicates that MHC Class I molecules can, in addition, exert a regulatory effect and influence the resulting immune responses . In this report we show that a monoclonal antibody (mAb) directed against a conserved region of the human leukocyte antigens (HLA)-A, -B, and -C was able to inhibit proliferation of human peripheral blood mononuclear cells induced by the superantigen, Staphylococcus enterotoxin A . While anti-HLA inhibition was associated with a decrease in IL-2 receptor (IL-2R) expression, the addition of exogenous IL-2 did not restore the proliferative response in the presence of anti-HLA mAb . The inhibition of DNA synthesis was also associated with a decrease in the expression of the early activation marker CD69 . These results suggest a critical role for HLA Class I molecules in the early events of human lymphocyte activation and proliferation as well as in their expression of the IL-2R.

Vet Rec, 1996 Aug 24, 139(8), 185 - 7
Tylosin in the treatment of canine superficial pyoderma; Harvey RG; Thirty dogs with superficial pyoderma were treated orally with tylosin at a dose of 20 mg/kg twice daily for three weeks . Staphylococcus intermedius was recovered from 21 (70 per cent) of the dogs . Twenty-two of the dogs were free of clinical signs after three weeks of treatment and two dogs responded to a further two weeks of treatment, giving a total response rate of 80 per cent . Five cases (16.6 per cent) failed to respond and three of these subsequently responded to other antibacterial treatment . One dog suffered transient gastritis after the doses of tylosin and subsequently responded to a different antibacterial agent.

J Mol Biol, 1996 Aug 23, 261(3), 372 - 85
Capsid targeting sequence targets foreign proteins into bacteriophage T4 and permits proteolytic processing; Mullaney JM et al.; A membrane-independent morphogenetic viral signal peptide is identified within bacteriophage T4 internal protein III (IPIII) . Utilizing a phagederived expression-packaging-processing system, which packages foreign proteins fused with IPIII into the phage capsid, a synthetic cleavage site introduced at the C terminus of IPIII, is demonstrated to be functional and permits processing of fusion proteins . IPIII, which possesses a native P21 cleavage site at its N terminus, is altered to possess a second P21 cleavage site at its C terminus where cleavage occurs by means of the scaffold proteinase P21 within the capsid . The altered IPIII was inserted into an expression vector to permit the creation of fusion proteins with staphylococcal nuclease, EcoRI endonuclease, beta-globin, and luciferase . Western immunoblot analysis of packaged T4eG326 indicates that the IPIII:fusion-proteins are packaged into phage and proteolytically processed, thus the synthetic P21 cleavage site positioned at the C terminus of IPIII is demonstrated to be functional, and 20 to 200 protein molecules are packaged per capsid . Truncation experiments identified the minimal portion of IPIII required to achieve targeting into the phage capsid as a ten amino acid residue from the N terminus, which includes the N-terminal methionine residue and the proteinase P21 cleavage site, designated the CTS (capsid targeting sequence) . The addition of the CTS to a fragment of luciferase permits the protein to be packaged and processed, which demonstrates that the CTS is by itself sufficient to target foreign protein to the capsid . The imputed dual function of the CTS is supported by site-directed PCR mutagenesis, which reveals two functionally separate domains of the CTS for targeting and processing . The CTS appears to function in a core-related targeting mechanism that directs a polymorphic set of proteins into the T-even capsid or scaffold . Although structure formation is often assumed to involve extended protein interfaces, the analysis shows that a limited but specific sequence, the CTS, drives the interaction required to achieve targeting.

Eur J Biochem, 1996 Aug 15, 240(1), 215 - 22
The use of photolabelled peptides to localize the substance-P-binding site in the human neurokinin-1 tachykinin receptor; Girault S et al.; The amino acid p-benzoyl-L-phenylalanine, (p-Bz)Phe, has been incorporated into substance P (SP), Arg-Pro-Lys-Pro-Gln-Gln-Phe-Phe-Gly-Leu-Met-NH2, to localize the agonist-binding domains of the human neurokinin-1 (NK-1) receptor overexpressed in a transfected mammalian cell line . The NK-1-specific agonist {Pro9}SP was modified at position 8 by (p-Bz)Phe and acylated at the N-terminus by a biotinyl sulfone reporter via a 5-aminopentanoyl spacer . After photolysis, the biotinyl sulfone moiety allowed easy and efficient removal of biotinylated fragments from the complex incubation mixture with streptavidin-coated beads . Direct elution from the beads with the matrix used for matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOFMS), which was facilitated by saturation of streptavidin sites with biotin, and subsequent MALDI-TOF mass spectrometry analysis allowed identification of the NK-1 fragments obtained after photolysis and proteolytic digestion . Trypsin digestion and combined trypsin/Staphylococcus aureus V8 protease enzymatic cleavage established that the site of covalent attachment of the photolabelled SP resides in the second extracellular loop Thr173-Arg177 . Cyanogen bromide cleavage shows that the probe is covalently attached to the methyl group of a methionine residue from human NK-1 . These experiments identified Met174 as the modified residue.

FEMS Microbiol Lett, 1996 Aug 15, 142(1), 59 - 63
Attachment of bacteria to model solid surfaces: oligo(ethylene glycol) surfaces inhibit bacterial attachment; Ista LK et al.; Bacterial cell attachment to the surfaces of self-assembled monolayers formed by the adsorption of omega-substituted alkanethiols on transparent gold films has been studied under defined bacterial culture and flow conditions . Phase contrast microscopy was used to quantify the attachment of two organisms, one of medical (Staphylococcus epidermidis) and one of marine (Deleya marina) importance . Self-assembled monolayers terminated with hexa(ethylene glycol), methyl, carboxylic acid and fluorocarbon groups were investigated . Over the range of experimental conditions, self-assembled monolayers formed from HS(CH2)11(OCH2CH2)6OH were found to be uniformly resistant to bacterial attachment, with a 99.7% reduction of attachment for both organisms when compared to the most fouled surface for each organism . On other surfaces, S . epidermidis and D . marina were shown to exhibit very different attachment responses to the wettability of the substratum . While the attachment of S . epidermidis correlated positively with surface hydrophilicity, D . marina showed a preference for hydrophobic surfaces . This study suggests that surfaces incorporating high densities of oligo(ethylene glycol) are good candidates for surfaces that interact minimally with bacteria.

J Immunol, 1996 Aug 15, 157(4), 1758 - 72
Inhibition of superantigen-induced proinflammatory cytokine production and inflammatory arthritis in MRL-lpr/lpr mice by a transcriptional inhibitor of TNF-alpha; Edwards CK 3rd et al.; We have used fas-defective MRL-lpr/lpr mice to study the effects of the staphylococcal enterotoxin superantigens on the development of autoimmune, inflammatory joint disease in animals that are susceptible to the development of rheumatoid arthritis-like disease . We show that systematic administration by a single i.p . injection of staphylococcal enterotoxin B (SEB; 10 micrograms/mouse) caused a mild, inflammatory arthritis +30 days postchallenge in the knee joints of young (< 2-mo-old) MRL-lpr/lpr mice, but not aged-matched MRL +/+ mice . In aged (> 8-mo-old) MRL-lpr/lpr mice, but not in aged MRL +/+ mice, SEB caused a severe, inflammatory arthritis, as assessed histologically, and systemic autoimmune disease, including glomerulonephritis and autoantibody production . Furthermore, in aged MRL-lpr/lpr mice, SEB but not heat-denatured SEB caused acute weight loss and elevated levels of serum proinflammatory cytokines . Compared with highly purified peritoneal macrophages obtained from either aged MRL +/+, young MRL-lpr/lpr, or young MRL +/+, peritoneal macrophages obtained from aged MRL-lpr/lpr mice constitutively expressed 2- to 10-fold greater levels of TNF-alpha, IL-1 beta, IL-6, and IL-10, and produced elevated amounts of these cytokines when treated in vitro with SEB . SEB-challenged aged MRL-lpr/lpr mice treated with anti-TNF mAb (100 micrograms/mouse; every other day), anti-V beta 8 TCR mAb (250 micrograms/mouse; every other day), or orally with the novel TNF-alpha inhibitor MDL 201,449A (9-{(1R, 3R)-trans-cyclopentan-3-ol} adenine; 25 mg/kg/day) exhibited reduced inflammatory arthritis, autoantibody formation, and serum TNF-alpha levels, but not IL-10 levels, after +30 days of treatment . These data suggest that SEB is an extremely potent macrophage-activating factor in vitro and in vivo, enhancing several aspects of autoimmune disease in MRL-lpr/lpr mice, and that anti-TNF therapies may have potential use in inflammatory arthritis.

J Immunol, 1996 Aug 15, 157(4), 1422 - 31
Implantation of IL-2-containing osmotic pump prolongs the survival of superantigen-reactive T cells expanded in mice injected with bacterial superantigen; Kuroda K et al.; In the present study we investigated the mechanism of deletion of superantigen (sAg)-reactive T cells expanded in sAg-injected mice . In staphylococcal enterotoxin A (SEA)-injected mice, IL-2 activity in serum peaked at 1 to 3 h and the expression of IL-2R alpha-chain (IL-2R alpha) on SEA-reactive (V beta 3+, or V beta 11+) T cells peaked at 6 to 12 h after the injection . Expansion of V beta 3+ or V beta 11+ T cells peaked at 2 days after the injection when most of these T cells were IL-2R alpha negative, and IL-2 activity was not detected at all in serum, suggesting the involvement of IL-2 deprivation in the deletion of expanded T cells . Implantation of an osmotic pump containing human rIL-2 (IL-2 pump) prolonged the expanded states of V beta 3+ or V beta 11+ T cells in SEA-injected C57BL/6 mice and of V beta 8+ T cells in SEB-injected MRL +/+ and Fas Ag-defective MRL-Ipr/Ipr mice . Adult thymectomy did not change at all the effect induced by implantation of IL-2 pump . DNA fragmentation was blocked substantially in mice co-treated with SEA and IL-2 pump . In addition, CD4+ T cell blasts, obtained by in vitro stimulation with rIL-2 of splenic CD4+ T cells from mice co-treated with SEA and IL-2 pump, produced substantial amounts of IL-2 upon restimulation with SEA . These results indicate that deprivation of IL-2 is deeply involved in the deletion of expanded sAg-reactive T cells and their anergy induction in sAg-injected mice.

Cancer Res, 1996 Aug 15, 56(16), 3731 - 6
Augmentation of antitumor immunity with bacterial superantigen, staphylococcal enterotoxin B-bound tumor cells; Shimizu M et al.; We have examined the effectiveness of a bacterial superantigen, staphylococcal enterotoxin B (SEB)-coupled tumor cells, to induce antitumor activity . SEB was chemically conjugated to tumor cells using a heterobifunctional cross-linking agent acting through NH2 and SH groups . V beta 8+ T cells were activated and increased in number after the culture with SEB-bound Meth A cells . The cultured T cells exhibited an antitumor activity in the Winn assay . Interleukin 2 (IL-2) receptor alpha + (IL-2R+) V beta 8+ T cells but not IL-2R+ V beta 6+ T cells increased in number in mice injected with SEB-bound Meth A cells . However, the percentages of V beta 8+ and V beta 6+ T cells did not change by this immunization . The antitumor effector cells were V beta 7- 8- CD4+ T cells . In vivo immunization with SEB-bound cells induced a strong antitumor activity, i.e., tumor-free mice/total mice = 14 of 15 (93%) for Meth A and 7 of 15 (47%) for hepatoma MH134 . The induced antitumor activity was both dose dependent and tumor specific . Treatment with SEB-bound cells prolonged the survival days of Meth A-bearing mice by 62% . These results suggest that SEB-bound tumor cells may be a powerful method for induction of in vivo antitumor activity.

Biochemistry, 1996 Aug 13, 35(32), 10441 - 7
Identification from a phage display library of peptides that bind to toxic shock syndrome toxin-1 and that inhibit its binding to major histocompatibility complex (MHC) class II molecules; Sato A et al.; Phage display technique is a powerful tool with which to identify novel binding sequences for antibody and receptor targets . Few studies, however, have used this technology to select affinity peptides for ligand molecules . Here, we screened a peptide phage library for binding to toxic shock syndrome toxin 1 (TSST-1) to examine whether peptide ligands for TSST-1 which mimic the structure of major histocompatibility complex (MHC) class II receptors could be identified . After three cycles of biopanning, four potent sequences reactive with TSST-1 were isolated (designated phages 2, 3, 8, and 11) . Selected phage were found to react specifically with TSST-1 but not with other staphylococcal exotoxins . A synthetic peptide (pep3) corresponding to the most frequently identified sequence (phage3) was shown to inhibit binding of all four isolated phage to TSST-1, suggesting that they bind to a common site on TSST-1 . Furthermore, pep3 was shown to compete with MHC class II molecules for binding to TSST-1 in a concentration-dependent manner . Comparison of their sequences with MHC class II molecules revealed that phage8 shared sequence homology with two regions of the beta chain of MHC class II molecules: amino acids 57-62, containing a residue (Tyr-60) involved in TSST-1 binding as suggested by X-ray crystallographic data of TSST-1-MHC class II complex; and amino acids 188-193, a region not previously known as a contact domain . These results suggest that the selected sequences recognized the MHC class II binding site on TSST-1 . Thus, affinity selection for peptides binding to ligand molecules (e.g., TSST-1) rather than their cognate receptors (e.g., MHC class II) from a random phage display library represents a useful approach to understanding receptor-ligand interactions.

Biochemistry, 1996 Aug 13, 35(32), 10328 - 38
Engineered disulfide bonds in staphylococcal nuclease: effects on the stability and conformation of the folded protein; Hinck AP et al.; Efforts to enhance the stability of proteins by introducing engineered disulfide bonds have resulted in mixed success . Most approaches to the prediction of the energetic consequences of disulfide bond formation in proteins have considered only the destabilizing effects of cross-links on the unfolded state (chain entropy model) {Pace, C . N., Grimsley, G . R., Thomson, J . A., & Barnett, B . J . (1988) J . Biol . Chem . 263, 11820-11825: Doig, A . J., & Williams, D . H . (1991) J . Mol . Biol . 217, 389-398} . It seems clear, however, that disulfide bridges also can influence the stability of the native state . In order to assess the importance of the latter effect, we have studied four variants of staphylococcal nuclease (V8 strain) each containing one potential disulfide bridge created by changing two wild-type residues to cysteines by site-directed mutagenesis . In each case, one of the introduced cysteines was within the type VIa beta turn containing cis Pro117, and the other was located in the adjacent extended loop containing Gly79 . In all four cases, the overall loop size was kept nearly constant (the number of residues in the loop between the two cysteines varied from 37 to 42) so as to minimize differences from chain entropy effects . The objective was to create variants in which a change in the reduction state of the disulfide would be coupled to a change in the position of the equilibrium between the cis and trans forms of the Xxx116-Pro117 peptide bond in the folded state of the protein . The position of this equilibrium, which can be detected by NMR spectroscopy, has been shown previously to correlate with the stability of the native protein . Its determination provides a measure of strain in the folded state . The thermal stabilities and free energies for unfolding by elevated temperature and guanidinium chloride were measured for each of the four mutants under conditions in which the introduced cysteines were cross-linked (oxidized) and unlinked (reduced) . In addition, reduction potentials were determined for each mutant . Formation of the different disulfide bridges was found to induce varying levels of folded state strain . The stabilization energy of a given disulfide bridge could be predicted from the measured perturbation energy for the peptide bond isomerization, provided that energetic effects on the unfolded state were calculated according to the chain entropy model . Undiagnosed strain in native states of proteins may explain the variability observed in the stabilization provided by engineered disulfide bridges.

Biochemistry, 1996 Aug 6, 35(31), 10234 - 9
Testing the correlation between delta A and delta V of protein unfolding using m value mutants of staphylococcal nuclease; Frye KJ et al.; The application of hydrostatic pressure to aqueous protein solutions results in the unfolding of the protein structure because the protein-solvent system volume is smaller for the unfolded state . Contributions to this decrease in volume upon unfolding (delta Vu) derive from altered interactions of the protein with solvent and are presumed to include electrostriction of charged residues, elimination of packing defects, and hydration of hydrophobic surfaces upon unfolding . If the contribution of hydrophobic surface area solvation to the observed volume change of unfolding were large and negative, as is generally assumed, then one would expect to find a correlation between the amount of surface area exposed on unfolding, delta A(u), and the volume change, delta Vu . In order to test this correlation, we have determined delta Vu for two mutants of staphylococcal nuclease, A69T + A90S and H121P, whose unfolding by denaturant is, respectively, either significantly more (28%) or significantly less (28%) cooperative than that observed for wild-type (WT) . This cooperativity coefficient or m value has been shown to correlate with delta A(u) . If, in turn, delta Vu is correlated with delta A(u), we would expect the m+ mutant, A69T + A90S, to exhibit a delta Vu that is more negative than WT nuclease, while the delta Vu for the m- mutant, H121P, should be smaller in absolute value . To verify the correlation between m value and delta A(u) for these mutants, we determined the xylose concentration dependence of the stability of each mutant at atmospheric pressure and as a function of pressure . The efficiency of xylose stabilization was found to be much greater for the m+ mutant than for WT, consistent with an increase in delta A(u), while that of the m- mutant was found to be only slightly greater than for WT, indicating that other factors may contribute to the denaturant m value in this case . Regardless of the denaturant m value or the effect of xylose on stability, the volume changes upon unfolding for both mutants were found to be within error of that observed for WT . Thus, there does not appear to be a correlation between the volume change and the change in exposed surface area upon unfolding . We have previously shown a lack of pH dependence of the volume change, ruling out electrostriction as a dominant contribution to delta Vu of nuclease . These studies implicate either compensation between polar and nonpolar hydration or excluded volume effects as the major determinant for the value of delta Vu.

Exp Eye Res, 1996 Aug, 63(2), 129 - 36
Aqueous and vitreous penetration of ciprofloxacin following different modes of systemic administration; Madu AA et al.; The overall importance of the peak or the mean serum concentrations as predictors of ocular drug penetration is unknown . To address this fundamental question with an agent which shows promise as adjunctive therapy in the treatment of endophthalmitis, we studied the penetration of ciprofloxacin into the aqueous and vitreous humors following three different modes of systemic administration . New Zealand white rabbits received either a single bolus dose (40 mg kg-1), three intermittent doses of 13.33 mg kg-1 evenly spaced over an 8 hr period, or a continuous infusion of 40 mg kg-1 over an 8 hr period . Pharmacokinetic analysis was performed using RSTRIP II, a non-linear, least square regression model analysis program . The serum area under the concentration-time curve (AUC) values for each mode of drug administration were similar: 32.9 micrograms hr ml-1 for single dose, 31.9 micrograms hr ml-1 for intermittent dose, and 33.8 micrograms hr ml-1 for continuous infusion modes . The percentage penetration into the aqueous and vitreous were also similar; 30.5% and 6.5% for a single dose, 31.6% and 7.4% for intermittent doses and 30.0% and 7.5% for continuous infusion . The penetration into the aqueous and vitreous humors was not influenced by mode of administration . As with other quinolones we have studied, elimination rates were similar for the central and peripheral compartments in the post-distributive phase . Vitreous humor ciprofloxacin concentrations achieved were below that which inhibits most Staphylococcus epidermidis, the most common isolate in patients with post-operative endophthalmitis.

Vet Immunol Immunopathol, 1996 Aug, 52(4), 301 - 11
Analysis of monoclonal antibodies reactive with molecules upregulated or expressed only on activated lymphocytes; Davis WC et al.; Monoclonal antibodies potentially specific for antigens expressed or upregulated on activated leukocytes were selected for further analysis from the panel submitted to the third international workshop on ruminant leukocyte antigens . The kinetics of expression of these activation antigens on resting peripheral mononuclear cells (PBMC) and PBMC stimulated with concanavalin A or staphylococcal superantigen SECI for 4, 24 or 96 h were compared, as well as their appearance on various subsets of cells . For some of them, a molecular mass could be determined after immunoprecipitation from radio-labeled, lectin-stimulated cells . Based on the results from the clustering, kinetic studies and biochemical data, evidence was gathered for assigning two additional mAbs to cluster BoCD25 (IL-2 receptor) and two mAbs to cluster BoCD71 (transferrin receptor) . Four mAbs recognized an early activation antigen predominantly expressed on gamma delta T cells in short-term cultures . A number of other activation antigens were further characterized.

Immunology, 1996 Aug, 88(4), 611 - 7
Isotype and antibody specificity of spontaneously formed immunoglobulins in pig fetuses and germ-free piglets: production by CD5- B cells; Cukrowska B et al.; Pig fetuses, colostrum-deprived newborns and germ-free (GF) piglets, animals in which B-cell development is not influenced by maternal regulatory factors, were employed to study the occurrence and specificity of natural antibodies (NAb) . Serum immunoglobulins of all isotypes were found in 44-day-old fetuses (the gestation period in pigs lasts 114 days) and their level, with predominating IgM, was increased during fetal ontogeny . In sera of fetuses at the end of embryonic life as well as of newborns and older GF piglets, antibody activity against autoantigens (thyroglobulin, hormones, ssDNA), phylogenetically conserved proteins (myosin), haptens (trinitrophenyl; TNP) and bacterial components (Escherichia coli O86, tetanic anatoxin) was detected by enzyme-linked immunosorbent assay . The antigen-biding activity of IgM NAb increased after isolation of the serum immunoglobulins on a Staphylococcus Protein A (SPA)-Sepharose column . IgM reactivity similar to that detected in serum was found in supernatants from polyclonally stimulated cultures of spleen of 8- and 12-day-old GF piglets . Pig fetal liver IgM+ B cells, which were able to produce IgM after polyclonal stimulation, did not express the CD5 molecule . Our results indicate that pig preimmune repertoire is comparable to that described in humans and mice, although in contrast to these species pig B-1 cells do not express CD5.

Immunology, 1996 Aug, 88(4), 586 - 92
Activation by mitogens and superantigens of axolotl lymphocytes: functional characterization and ontogenic study; Salvadori F et al.; Urodele amphibians have weak and slow immune responses compared to mammals and anuran amphibians . Using new culture conditions, we tested the ability of lymphocytes of a well-studied salamander, the Mexican axolotl (Ambystoma mexicanum) to proliferate in vitro with diverse mitogenic agents . We demonstrated that the axolotl has a population of B lymphocytes that proliferate specifically and with a high stimulation index to the lipopolysaccharide (LPS) known as a B-cell mitogen in mammals . This proliferative capacity is observed without significant changes throughout ontogenesis . In the presence of LPS, axolotl B lymphocytes are able to synthesize and secrete both isotopes of immunoglobulin described in this species, IgM and IgY . Moreover, a distinct lymphocyte subpopulation is able to poliferate significantly in response to the mitogens usually known as T-cell specific in mammals, phytohaemagglutinin (PHA) and concanavalin A (Con A) . The activated cells are T lymphocytes, as shown by depletion experiments performed in vitro with monoclonal antibodies, and in vivo by thymectomy . Splenic T lymphocytes of young axolotls (before 10 months) do not have this functional ability, which suggests maturation and/or migration phenomena during T-cell ontogenesis in this species . Axolotl lymphocytes are able to proliferate in vitro with a significant stimulation index to staphylococcal enterotoxins A and B (SEA and SEB) . These products act on mammalian lymphocytes as superantigens: in combination with products of the major histocompatibility complex (MHC), they bind T-cell receptors with particular V beta elements . The fact that these superantigens are able to activate lymphocytes of a primitive vertebrate suggests a striking conservation of molecular structures implied in superantigen presentation and recognition.

Alcohol Clin Exp Res, 1996 Aug, 20(5), 900 - 7
Regulation of human monocyte functions by acute ethanol treatment: decreased tumor necrosis factor-alpha, interleukin-1 beta and elevated interleukin-10, and transforming growth factor-beta production; Szabo G et al.; We and others have previously shown that even acute ethanol exposure has the capacity to modulate immune functions, particularly monocyte functions . Herein, we tested the hypothesis that acute ethanol treatment inhibits inflammatory, while increasing inhibitory cytokine production in human blood monocytes that, in turn, could contribute to the overall immune abnormalities seen after alcohol use . Our data show that in vitro treatment of blood monocytes with a physiologically relevant dose of alcohol (25 mM) results in significantly decreased induction of tumor necrosis factor-alpha (TNF alpha) and interleukin (IL)-1 beta by bacterial stimulation of either Gram-positive {staphylococcal enterotoxin B (SEB), 1 microgram/ml of SEB} or Gram-negative {lipopolysaccharide (LPS), 1 microgram/ml of LPS} origin both at the protein and mRNA levels . In contrast, acute ethanol treatment induces monocyte production of mediators with immunoinhibitory potential, including transforming growth factor-beta and IL-10 . We further show that ethanol not only induces monocyte/macrophage (Mo) IL-10 and transforming growth factor-beta, but even augments bacterial (both LPS and SEB) stimulation-induced production of both of these cytokines . IL-10 is a potent inhibitor of Mo TNF alpha production . We found that ethanol-induced elevation in Mo IL-10 levels contributes to the decreased Mo TNF alpha production to bacterial challenge in ethanol-exposed Mo . However, mRNA levels for TNF alpha are downregulated as early as 1.5 hr after ethanol treatment, suggesting that ethanol likely has an IL-10 independent, direct effect on early signaling events of TNF alpha induction.

J Dairy Res, 1996 Aug, 63(3), 361 - 8
Field study on the relationship between teat thickness changes and intramammary infections; Zecconi A et al.; The aim of this study was to describe the results of teat thickness measurement applied routinely in three commercial dairy herds and to evaluate the influence of machine-induced teat thickness changes on intramammary infection and the frequency of new infection . A total of 1018 fore milk samples and the same number of teat apex measurements have been evaluated . Overall, relative teat thickness changes were normally distributed (mean -0.16%, SD 10.15%), while a specific pattern could be observed within herds . Increases in teat thickness of > 5% were significantly associated with infection and new infection (odds ratio > 1), but the association was not significant when teat thickness decreased by more than 5% . When results were classified according to aetiology, analysis showed that coagulase-negative staphylococcal infections were significantly associated with both increases and decreases in teat thickness numerically greater than 5%.

Spine, 1996 Aug 1, 21(15), 1820 - 3
Conservative therapy of atlantoaxial osteomyelitis . A case report; Lam CH et al.; STUDY DESIGN: A rare case of C1-C2 vertebral osteomyelitis treated conservatively is described . The radiologic findings as well as the follow-up evaluation are reported . OBJECTIVE: To increase knowledge about the pathogenesis and treatment of vertebral osteomyelitis in the high cervical region . SUMMARY OF BACKGROUND DATA: This is one of the first cases reported of successful conservative treatment of osteomyelitis at this level . METHODS: In a 58-year-old man with lumbar staphylococcal infection, a subsequent cervical infection developed . Because the lumbar spondylitis was treated promptly, the cervical osteomyelitis was treated at a very early stage of development . RESULTS: Operative decompression is the treatment most often used in osteomyelitis at the C1-C2 level . This is an extremely unusual circumstance in which early treatment of the infection negated the need for surgery . CONCLUSION: Conservative treatment of osteomyelitis at the C1-C2 level can be efficacious in the correct setting.

Protein Sci, 1996 Aug, 5(8), 1737 - 41
Crystal structure of a biologically inactive mutant of toxic shock syndrome toxin-1 at 2.5 A resolution; Papageorgiou AC et al.; Toxic shock syndrome toxin-1 (TSST-1) is one of a family of staphylococcal exotoxins recognized as microbial superantigens . The toxin plays a dominant role in the genesis of toxic shock in humans through a massive activation of the immune system . This potentially lethal illness occurs as a result of the interaction of TSST-1 with a significant proportion of the T-cell repertoire . TSST-1, like other superantigens, can bind directly to class II major histocompatibility (MHC class II) molecules prior to its interaction with entire families of V beta chains of the T-cell receptor (TCR) . The three-dimensional structure of a mutant (His-135-Ala) TSST-1 was compared with the structure of the native (wild-type) TSST-1 at 2.5 A resolution . The replacement of His 135 of TSST-1 with an Ala residue results in the loss of T-cell mitogenicity and toxicity in experimental animals . This residue, postulated to be directly involved in the toxin-TCR interactions, is located on the major helix alpha 2, which forms the backbone of the molecule and is exposed to the solvent . In the molecular structure of the mutant toxin, the helix alpha 2 remains unaltered, but the His to Ala modification causes perturbations on the neighboring helix alpha 1 by disrupting helix-helix interactions . Thus, the effects on TCR binding of the His 135 residue could actually be mediated, wholly or in part, by the alpha 1 helix.

Nippon Kyobu Geka Gakkai Zasshi, 1996 Aug, 44(8), 1185 - 92
{A case report of active aortic prosthetic valve endocarditis due to methicillin-resistant Staphylococcus epidermidis}; Asakura T et al.; A 71-year-old woman with active aortic prosthetic endocarditis due to Methicillin-resistant Staphylococcus epidermidis (MRSE) and subannular mycotic aneurysm and paravalvular leakage and acute mitral regurgitation underwent emergent surgical treatment . The mycotic aneurysm was closed using a prosthetic patch after surgical debridement . Re-aortic valve replacement with a 21-mm Hancock II prosthesis was performed at the paraannular position by utilizing the patch . Mitral valve was also replaced with a 27-mm Hancock II prosthesis . Antibiotic therapy was provided by vancomycin combined with rifampicin and gentamicin . The following regimen was given, vancomycin 1 g i.v . q12h for 6 weeks plus gentamicin 80 mg/day i.v . for 4 weeks plus rifampicin 450 mg/day orally for 6 weeks . Vancomycin and gentamicin doses were modified appropriately according to the monitored serum levels in the patient with renal failure . Postoperative course was uneventful . The patient is doing well 11 months after surgery and no recurrence of infection has been seen . We conclude that prompt surgical removal of the infected sources and appropriate antibiotic therapy based on the bacteriology may be the only curative treatment for uncontrolled infection at the active phase of MRSE prosthetic endocarditis.

Cell Immunol, 1996 Aug 1, 171(2), 240 - 5
Superantigen-induced Langerhans cell depletion is mediated by epidermal cell-derived IL-1 alpha and TNF alpha; Shankar G et al.; The purpose of this study was to examine the role of cytokines in staphylococcal enterotoxin-A (SEA)-induced epidermal Langerhans cell (LS) depletion . This was accomplished by analyzing the effect of SEA on cytokine secretion by cultured epidermal cell populations by means of ELISA and by assessing the capacity of cytokines and cytokine-specific antibodies to affect epidermal LC density (as measured by immunoperoxidase staining of epidermal cells bearing surface Ia) . The results of this study indicate that SEA induces the secretion of IL-1 alpha and TNF alpha by epidermal cells, that these cytokines induce LC depletion from epidermis, and that antibodies specific for these agents inhibit the depletion of LC by SEA . Taken together, these findings suggest that IL-1 alpha and TNF alpha may play essential roles in SEA-mediated depletion of LC from murine epidermis.

J Pharmacol Exp Ther, 1996 Aug, 278(2), 800 - 7
Agonist synergism in airway smooth muscle contraction; Gerthoffer WT; Hyperreactive responses of asthmatics to bronchoconstrictor agonists are caused by mediators produced by a variety of cell types within the airways . Nerves, mast cells, eosinophils, airway epithelia and airway smooth muscle cells probably all interact to increase bronchomotor tone in response to challenge with allergenic stimuli . In addition to important cell-cell interactions, there may be a significant postjunctional component of airway hyperreactivity in which mediators interact at the level of airway smooth muscle cells . To test this hypothesis, I investigated synergistic interactions of methacholine (MCH), histamine and serotonin using intact and chemically skinned canine tracheal smooth muscle . A threshold concentration of histamine (100 nM) significantly increased force when it was added 20 min after or 10 min before stimulation with low concentrations of MCH (1-10 nM) . A threshold concentration of serotonin (10 nM) also significantly increased contractions induced by MCH . Serotonin (10 nM) added during a steady-state contraction induced by 6 or 10 nM MCH increased force and increased fura-2 fluorescence, which suggests that force increases in part because myoplasmic Ca++ increases . I also tested the hypothesis that mechanisms beyond the initial steps of signal transduction contribute to synergism by permeabilizing tracheal smooth muscle fibers with staphylococcal alpha-toxin . Histamine (30 microM), MCH (1 microM), GTP-gamma-S (100 microM) and phorbol dibutyrate (1 microM) all potentiated contractions induced by 1 microM Ca++ in skinned fibers . These data suggest that postjunctional components of airway hyperreactivity may be a combination of synergistic effects of agonists occurring at the level of excitation-contraction coupling as well as sensitization of contractile proteins to Ca++.

J Exp Med, 1996 Aug 1, 184(2), 725 - 33
Function of the p55 tumor necrosis factor receptor "death domain" mediated by phosphatidylcholine-specific phospholipase C; Machleidt T et al.; Tumor necrosis factor (TNF) is a pleiotropic mediator of inflammation that has been implicated in the pathogenesis of devastating clinical syndromes including septic shock . We have investigated the role of a TNF-responsive phosphatidylcholine-specific phospholipase C (PC-PLC) for the cytotoxic and proinflammatory activity of TNF . We show here that the cytotoxicity signaled for by the so-called "death domain" of the p55 TNF receptor is associated with the activation of PC-PLC . The xanthogenate tricyclodecan-9-yl (D609), a specific and selective inhibitor of PC-PLC, blocked the cytotoxic action of TNF on L929 and Wehi164 cells . In vivo, D609 prevented both adhesion molecule expression in the pulmonary vasculature and the accompanying leukocyte infiltration in TNF-treated mice . More strikingly, D609 protects BALB/c mice from lethal shock induced either by TNF, lipopolysaccharide, or staphylococcal enterotoxin B . Together these findings imply PC-PLC as an important mediator of the pathogenic action of TNF, suggesting that PC-PLC may serve as a novel target for anti-inflammatory TNF antagonists.

Infect Immun, 1996 Aug, 64(8), 3410 - 5
Purification and characterization of the staphylococcal slime-associated antigen and its occurrence among Staphylococcus epidermis clinical isolates; Baldassarri L et al.; The Staphylococcus epidermidis slime-associated antigen (SAA) was purified and characterized . N-Acetyl-glucosamine accounted for 70% of the dry weight of SAA, which was immunolocalized on the ruthenium red-positive material produced by slime-positive strains . A total of 59% of slime-producing S . epidermidis clinical isolates expressed SAA, while the phenotype slime- SAA+ was never recovered.

J Immunol, 1996 Aug 1, 157(3), 1200 - 6
Complement activation by a B cell superantigen; Kozlowski LM et al.; Staphylococcal protein A (SpA), acting as a B cell superantigen, binds to the Fab region of human VH3+ Igs . Using SpA abrogated of its IgG Fc binding activity (Mod SpA) as a model B cell superantigen, we determined whether such an interaction causes complement activation . Addition of Mod SpA to human serum led to complement consumption and the generation of C3a . To determine whether this complement activation 1) was due to an interaction between VH3+ Igs and the Fab binding site of SpA and 2) proceeded via the classical complement pathway, we tested a panel of monoclonal IgM proteins for the ability to hind C1q following interaction with SpA . C1q binding was restricted to SpA-reactive, VH3+ IgM proteins . To formally determine whether the binding of SpA to the reactive VH3+ IgM proteins led to complement activation, we reconstituted the serum from a hypogammaglobulinemic patient with monoclonal IgM proteins and measured complement consumption and C3a generation following the addition of Mod SpA . We observed complement consumption and C3a production only in Mod SpA-treated serum reconstituted with a VH3+, SpA-binding, IgM protein . Taken together, these results provide compelling evidence that the interaction of the Fab binding site of SpA and VH3+ Igs can lead to complement activation via the classical pathway . This novel interaction may have significant implications for the in vivo properties of a B cell superantigen.

Am J Pathol, 1996 Aug, 149(2), 629 - 38
Prelabeled glycoprotein Ib/IX receptors are not cleared from exposed surfaces of thrombin-activated platelets; White JG et al.; The present investigation has re-examined the hypothesis proposing that glycoprotein (GP)Ib/IX receptors for von Willebrand factor are rapidly cleared from exposed surfaces to internal membrane systems after activation of platelets by thrombin in suspension . Platelets were prelabeled with either a polyclonal antibody to GPIb alpha, antiglycocalicin (A-Gl), or a cocktail of two monoclonal antibodies, AP1 and 6D1, exposed to 0.1 or 0.2 U/ml thrombin for 5 or 10 minutes, fixed and stained with Staphylococcus protein A coupled to gold to detect A-Gl or goat anti-mouse IgG bound to gold particles to locate AP1 and 6D1 before or after preparation of frozen thin sections or embedding for plastic thin sections . The frequency and distribution of protein-A-gold markers for GPIb/IX on thrombin-activated platelets viewed in thin plastic sections did not differ from the density on resting platelets stained with A-Gl . Cryosections of A-Gl-prelabeled platelets labeled again on cryosections revealed GPIb present on linings of the open canalicular system of resting and activated platelets, but the density of gold in interior channels and frequency of gold particles on exterior surfaces were not altered by thrombin stimulation . Platelets prelabeled with the cocktail of 6D1 and AP1 and studied in cryosections also failed to reveal uptake of GPIb/IX receptors into the open canalicular system after activation by thrombin . The findings do not support the concept that thrombin causes clearance of GPIb/IX receptors from exterior surfaces to interior membranes of activated platelets.

J Infect Dis, 1996 Aug, 174(2), 338 - 45
Superantigen vaccines: a comparative study of genetically attenuated receptor-binding mutants of staphylococcal enterotoxin A; Bavari S et al.; Superantigens exert their pathologic effects by direct binding to major histocompatibility complex (MHC) class II molecules and T cell antigen receptors (TCR), thus circumventing the normal, antigen-specific immune response . A direct link between disease and toxin suggests an excellent opportunity for vaccine intervention . Site-directed mutants of staphylococcal enterotoxin A (SEA) that have attenuated binding to either the TCR or the MHC class II molecule were developed . Both kinds of SEA mutants induced high levels of antibody against SEA when used as vaccines, and the immunized animals were fully protected when challenged with wild type toxin . However, a residual lethality was associated with the attenuated TCR-binding mutant . These results, combined with an understanding of the molecular nature of superantigen and receptor interactions, indicate that targeting MHC class II binding by site-directed mutagenesis will produce the most effective vaccine.

Gastroenterology, 1996 Aug, 111(2), 462 - 71
Interferon gamma plays a critical role in T cell-dependent liver injury in mice initiated by concanavalin A; Kusters S et al.; BACKGROUND & AIMS: T cell-dependent liver injury involving endogenous tumor necrosis factor (TNF) alpha can be induced by either concanavalin A in naive mice or by activating anti-CD3 antibody or staphylococcal enterotoxin B in D-galactosamine-sensitized mice . In this study, the role of interferon gamma (IFN-gamma) in these T-cell models was addressed . METHODS: Mice were pretreated with a neutralizing anti-mouse IFN-gamma antiserum before injection of T cell-activating agents . Plasma cytokine and transaminase levels were determined . Apoptotic cell death was assessed by hepatic DNA fragmentation . RESULTS: Anti-IFN-gamma antiserum significantly protected mice from concanavalin A-induced liver injury . Circulating IFN-gamma was completely suppressed, and TNF was reduced by 50% . Recombinant TNF-alpha administered to mice treated with concanavalin A and anti-IFN-gamma antiserum failed to initiate liver injury . Similar results were obtained with recombinant IFN-gamma in concanavalin A-challenged mice under the condition of TNF neutralization . Neither hepatic DNA fragmentation nor release of transaminases was inhibited by anti-IFN-gamma antiserum when liver injury was induced by staphylococcal enterotoxin B or anti-CD3 antibody in D-galactosamine-sensitized mice . CONCLUSIONS: Both TNF as well as IFN-gamma are critical mediators of liver injury in concanavalin A-treated mice, whereas hepatic DNA fragmentation and liver failure in the D-galactosamine models depend only on TNF.

J Biotechnol, 1996 Jul 31, 48(3), 241 - 50
Integrated production of human insulin and its C-peptide; Nilsson J et al.; The potential for the development of an integrated process for production of human insulin and its C-peptide in Escherichia coli has been investigated . Human proinsulin was produced intracellularly in E . coli fused to two synthetic IgG-binding domains (ZZ) derived from staphylococcal protein A . High expression levels (3 g/l culture) of the gene product, which accumulated as inclusion bodies, was obtained . Solubilization of inclusion bodies by oxidative sulfitolysis and subsequent renaturation was performed directly after cell lysis and pellet wash . IgG affinity chromatography was used for efficient recovery of pure proinsulin fusion protein in a single step . Monomers of the proinsulin fusion protein constituted approximately 70% . A single step conversion of the fusion protein into insulin and C-peptide by trypsin and carboxypeptidase B treatment was achieved by engineering the junction between proinsulin and its affinity handle, ZZ . Characterization of the cleavage products by reversed phase chromatography (RPC) verified that human insulin and C-peptide were generated and that the ZZ affinity handle was resistant to cleavage . Human insulin and C-peptide were recovered with high yields by preparative reversed-phase high performance liquid chromatography (RP-HPLC) . The potential use of the presented scheme for large-scale production of recombinant insulin and/or its C-peptide is discussed.

J Mol Biol, 1996 Jul 26, 260(4), 570 - 87
Accretion of structure in staphylococcal nuclease: an 15N NMR relaxation study; Alexandrescu AT et al.; 15N main-chain dynamics are compared in four forms of staphylococcal nuclease with different stabilities to unfolding: (1) SN-T, the ternary complex of the protein, Ca2+, and the inhibitor thymidine 3', 5'-bisphosphate; (2) SN, the protein in the absence of added ligands; (3) SN-OB, a folded fragment that corresponds to an "OB-fold" subdomain; (4) delta 131 delta, a denatured 131-residue fragment . SN-T exhibits very little internal motion on the nanosecond timescale . In SN, a moderate increase in flexibility is observed for the first three strands of the five-stranded beta-sheet, and for a loop between strands 4 and 5 . In SN-OB, the loops between strands 3 and 4, and between strands 4 and 5, are extremely flexible on the nanosecond timescale . While the beta-sheets of SN-OB and SN have comparable dynamics on the nanosecond timescale, the beta-sheet in SN-OB experiences additional motion on a slower timescale of 330(+/-170) microseconds . We attribute the latter to interconversion between a major folded (> or = 98%) and a minor unfolded (> or = 2%) conformation . In delta 131 delta, the first three strands of beta-sheet experience conformational averaging on the millisecond timescale . Most of the remainder of the polypeptide chain is highly flexible on the nanosecond timescale . When all four forms of nuclease are considered, there is an increase in the proportion of residues with large amplitude internal motions (low order parameters) as the stability of the folded state is decreased . Residues with low order parameters cluster to distinct regions of the chain, and have H alpha chemical shifts and 3JHN-H alpha coupling constants that tend towards "random coil" values . Conversely, a trend towards uniformly high order parameters suggests a consolidation of structure with increasing stability to denaturation.

Int J Cancer, 1996 Jul 17, 67(2), 232 - 7
Tumor-infiltrating lymphocytes can be activated in situ by using in vivo activants plus F(ab')2 bispecific antibodies; Thibault C et al.; In vitro-activated T lymphocytes can be retargeted with anti-CD3 x anti-tumor bispecific antibodies (BsAb) to kill tumor cells in vitro and in vivo . The purpose of the present study was to examine the systemic and intra-tumor effects of in vivo T-cell activation with BsAb, staphylococcal enterotoxin B (SEB), and beta-glucan in combination with BsAb as a retargeting agent . CL-62 melanoma cells were injected subcutaneously into C3H/ HeN mice . Mice were subsequently treated with BsAb alone or with SEB or beta-glucan plus BsAb . Fresh splenocytes, lymph-node cells and tumor-infiltrating lymphocytes (TIL) were tested for their proliferative response using incorporation of 3H-thymidine, and for their ability to lyse CL-62 cells in the presence or absence of BsAb in 4-hr 51Chromium release assays . Toxicity of treatments was assessed in a D-galactosamine model . BsAb, alone or combined with beta-glucan, had essentially no effect on systemic T-cell cytotoxicity, and essentially no effect on systemic proliferation, unless exogenous IL-2 was provided . At the tumor site, BsAb alone, BsAb plus beta-glucan, and SEB plus BsAb all significantly increased BsAb-mediated TIL cytotoxicity . In contrast to the TIL-limited effects of BsAb and of BsAb plus beta-glucan, SEB plus BsAb markedly increased both systemic and intra-tumor T-lymphocyte activation . Toxicity correlated with measures of systemic activation, with limited effects from BsAb alone and from beta-glucan plus BsAb, and with marked lethality from SEB plus BsAb . Overall, these results suggest moderate intra-tumor activation of TIL, but no measurable systemic activation after in vivo treatment with BsAb or beta-glucan plus BsAb . SEB plus BsAb results in complete T-cell activation in both systemic and intra-tumor compartments, but at the expense of increased systemic toxicity . In conclusion, TIL can be activated in situ with different combinations of in vivo activants . In vivo-activated TIL can be retargeted with bispecific antibodies to lyse tumor cells, and may be an alternative to ex vivo T-cell activation and adoptive transfer therapy.

J Mol Biol, 1996 Jul 5, 260(1), 22 - 33
Sequence-specific DNA binding of the phage Mu C protein: footprinting analysis reveals altered DNA conformation upon protein binding; Ramesh V et al.; The mom gene of bacteriophage Mu, which codes for a DNA modification function, is regulated in a complex manner at both transcriptional and translational levels . The phage-encoded C protein functions as an activator of mom transcription . The mom promoter has features of an activator-dependent weak promoter, and the C binding site is located upstream and overlapping the -35 region and includes the palindromic sequence TTAT(N)6ATAA . The interactions of this activator protein at its binding site in Pmom has been investigated using four different chemical footprinting reagents . The protein footprint spans a region of 18 to 25 bp, depending on the nature of the chemical reagent used . Dimethylsulfate protection experiments revealed the base-specific interactions . The protected guanines are separated by 15 bp and are located beyond the interrupted palindromic sequence . A tripartite footprint was observed with hydroxyl radical, generated by Fe(II)-EDTA, which shows the binding of the protein to one face of the helix . The extent of protection conferred by the bound protein, however, is not uniform, suggesting that the interaction is asymmetric . The chemical nuclease 1,10-phenanthroline-copper, a minor groove specific ligand, shows hyper-reactivity upon protein binding in the top strand nucleotide triplet CAC, again confirming the protein-induced alterations in DNA conformation . Gel exclusion chromatography and chemical crosslinking experiment with the purified protein suggest that this mode of interaction is accomplished by a dimeric protein . This observation is supported by electrophoretic mobility shift assay using heterodimer of pure C protein and staphylococcal protein A-C fusion . The deletion analysis implicates a role for the carboxyl-terminal region of the protein in DNA binding.

Rom J Morphol Embryol, 1996 Jul-Dec, 42(3-4), 169 - 78
Anatomoclinical and bacteriological study on chronic marginal periodontal disease . Therapy with staphylococcic vaccine; Laky D et al.; Histological, histochemical and electronmicroscopic investigations were carried out on gum biopsies taken from cases with chronic marginal periodontal disease before and after the treatment with staphylococcic vaccine, thus, morphopathologically proving the findings of Gafar et al . (1985) and of Georgescu et al . (1973; 1974; 1975; 1979; 1995) . Before treatment, gum lesions were severe, consisting in an abundance of polymorphic inflammatory infiltrates in the chorion along with oedema and disorganised connective fibres, atrophies and ulceration of the mucosa, purulent deposits at the surface with bacteria and fungi . After the treatment with the staphylococcic vaccine, an epithelial regeneration was seen together with the absence of the chronic inflammation . The intensely fibroparius granulated tissue was also noted, in all cases observing abundant connective fibres, accounting for good results after treatment, notably the firmness of the tooth fitting.

Microb Drug Resist, 1996 Summer, 2(2), 239 - 43
An electron microscopic study of clinical and laboratory-derived strains of teicoplanin-resistant Staphylococcus haemolyticus; Giovanetti E et al.; Staphylococcal resistance to glycopeptides (which involves more teicoplanin than vancomycin) is uncommon and largely confined to Staphylococcus haemolyticus, an emerging nosocomial pathogen with a tendency to develop antibiotic resistance . In this study, six S . haemolyticus strains, including two isogenic pairs of teicoplanin-susceptible/-resistant strains and two resistant clinical isolates, were used in a morphologic and morphometric electron microscope investigation . Cells from both clinical and laboratory-derived teicoplanin-resistant strains exhibited abnormally roughened, irregular outlines when observed by transmission electron microscopy . However, no significant differences in cell wall thickness resulted from morphometric analysis when the susceptible/resistant cells of the two isogenic pairs were compared . By scanning electron microscopy, an abnormally roughened, blistered surface was associated with teicoplanin-resistant cocci . A certain variability was noted between strains, not clearly related to the resistance level . In freeze-fracture investigations, a higher number per square micrometer of intramembrane particles, more significant in the E than in the P membrane fracture face, was observed in the laboratory-derived resistant clones as compared to susceptible parent strains . Further studies are needed to understand the cause-effect relation between these ultrastructural alterations and staphylococcal resistance to teicoplanin (but not to vancomycin).

Zh Mikrobiol Epidemiol Immunobiol, 1996 Jul-Aug, (4), 71 - 4
{An immunomodifier--staphylococcal anatoxin--prevents the development of immunosuppression caused by informational stress in mice}; Ozherelkov SV et al.; The action of information stress for 14 days leads to the development of immunosuppression, which is manifested by the suppression of humoral response to sheep red blood cells (SRBC) and the decrease of resistance to Langat virus having low pathogenicity . As shown in this investigation, an immunomodifier, purified staphylococcal toxoid (PST), protects experimental animals from the immunosuppressive effect of information stress . After the injection of PST to stress-affected mice in doses of 15 or 1.5 binding units per animal on days 9, 11 and 13 of the experiment their humoral response to SRBC and resistance to Langat virus are partially restored (by 45-60%).

Izv Akad Nauk Ser Biol, 1996 Jul-Aug, (4), 499 - 501
{The effect of long-term UV radiation exposure on the skin autonomous microflora and on body nonspecific resistance}; Strzhizhovskii AD et al.; Hairless mice of strain HRS were exposed to vertical UV-B-irradiation (280-320 nm) at daily doses of 1 or 2 kJ/m2 (biologically effective doses 200 and 400 J/m2) five days a week for 13 and 6 weeks . As the length of exposure increased, the abundance of automicroflora of the dorsal skin first decreased, then exceeded the control value, was normalized, and remained at the normal level until the end of the experiment . The rates of effect appearance and disappearance, just as its amplitude, increased with the daily doses . No changes were found in resistance to staphylococcal alpha-toxin after its post-irradiation intraperitoneal injection.

Ann Cardiol Angeiol (Paris), 1996 Jul-Sep, 45(7), 369 - 76
{Mediastinitis after cardiac surgery . A 10-year evaluation (1985-1995)}; Valla J et al.; From June 1985 to May 1995, 9,814 patients were operated for a cardiac procedure with cardiopulmonary by-pass . Mean age was 61,3 years . The most frequent procedure was coronary surgery (45%), followed by valvular surgery (34%) then combined surgery (11%) and other surgery (4%) . 66 cases of mediastinitis were observed: 38 from June 1985 to May 1990 (first group), 28 from June 1990 to May 1995 (second group) . The changes between the two groups was antibiotic prophylaxis using Cefuroxime in the first group and Cefamandole in the second and also an impairment of general status of the patients in the second group . Staphylococcus remains the most frequent organism in both groups and for Gram negative bacteria was less frequent in the second group . Several risks factors mediastinitis were identified (males, emergency, diabetes mellitus, obesity, redo, patient of first group, duration of Cardiopulmonary by pass for 100 minutes, mechanical ventilation greater than 48 hours) and the most important factor was the need for mechanical ventilation for more than 48 hours . The mortality rate was 39.4% (26 patients) . Identified risk factors of mortality were age over 65 years, females, poor constitution, and cardio/thoracic ratio > 0.55 . CONCLUSION: Mediastinitis after cardiac surgery remains a serious complication . In this series we observed a decrease of mediastinitis rates, especially in the second group (p < 0.001) . In high risk patients, specific preoperative methods of patient care may be able to prevent such complications . When mediastinitis appears, and when debridement is necessary, a cover procedure seems necessary in elderly or poor constitution patients.

J Refract Surg, 1996 Jul-Aug, 12(5), 642 - 4
Bacterial keratitis after photorefractive keratectomy; Amayem A et al.; Two patients who had excimer laser photorefractive keratectomy (PRK) for myopia developed bacterial keratitis, one from Staphylococcus epidermidis and the other with a negative culture . Both were treated with topical antimicrobial agents . One eye recovered an uncorrected visual acuity of 20/20 . The other was left with a moderate subepithelial scar and an uncorrected visual acuity of 20/150.

Clin Exp Rheumatol, 1996 Jul-Aug, 14(4), 359 - 66
Superantigens and experimental SLE induced by idiotypic dysregulation; Baharav E et al.; OBJECTIVE: The effects of the superantigens (SAgs) Staphylococcal Enterotoxin B (SEB), Toxic Shock Syndrome Toxin-1 (TSST-1) and Mycoplasma Arthritidis Mitogen (MAM) were examined on the induction and on the course of experimental SLE-like disease . METHODS: Immunization of BALB/c mice with human anti-DNA mAb (MIV-7) carrying the pathogenic idiotype 16/6 emulsified in complete Freund's adjuvant (CFA), followed by a boost of MIV-7/PBS 3 weeks later, generated an experimental SLE via an idiotypic dysregulation . RESULTS: After immunization with MIV-7/SAg, replacing the MIV-7 boost by SAg, and then injecting SAg 7 weeks after the regular induction of the SLE-like disease, the mice failed to produce anti-hIgM and dsDNA Ab up to 6 months after the induction . The mice immunized with MIV-7/CFA and boosted with the SAg had high titers of anti-hIgM but no detectable anti-dsDNA Ab . In both experimental groups low titers of anti-CL Abs developed in 25/40 (62%) and 30/38 (79%) of the mice respectively, including the control mice immunized with non-pathogenic human IgM/SAg or PBS/SAg . The mice immunized according to the "classical" protocol showed increased titers of anti-dsDNA Ab (22%) and anti-CL Ab (28%) during 10 weeks of observation . In contrast SEB, TSST-1 and MAM induced a 29%, 1% and 17% reduction in the anti-DNA titers and a 32%, 15% and 12% reduction in the anti-CL titers, respectively . CONCLUSIONS: These data suggest that the SAg tested here cannot replace the effect of CFA in the induction of the primary humoral response . The SAgs TSST-1, SEB and MAM did not induce the SLE-like disease following idiotypic modulation . Moreover, they may have had a suppressive effect on the idiotypic network in our model . The appearance of anti-CL Abs in almost all the experimental groups including the naive mice supports the possibility that microbial SAgs can induce the production of autoantibodies by different mechanisms . The SAgs TSST-1, SEB and MAM reduced autoantibody production in the serologically established idiotypic-induced experimental SLE-like murine model . This beneficial effect may indicate new directions for research on the management of SLE.

J Vet Med Sci, 1996 Jul, 58(7), 711 - 3
Characterization of non-pigmented Staphylococcus chromogenes; Saito K et al.; A large number of non-pigmented Staphylococcus chromogenes were isolated from the skin of piglets with exudative epidermitis and healthy pigs . Their characteristics were homologous with S . chromogenes type strain, except for pigment production . Strains of non-pigmented S . chromogenes exhibited high levels of DNA homology with S . chromogenes type strain . The colony morphology and pigmentation of non-pigmented S . chromogenes was very similar to S . hyicus type strain, but their characteristics differ in hyaluronidase production, heat stable DNase, Tween 80 hydrolysis and bacitracin resistance . Further, DNA homology drew a distinction between non-pigmented S . chromogenes and S . hyicus type strain.

Bone Marrow Transplant, 1996 Jul, 18(1), 193 - 8
Thrombotic microangiopathy as a complication of high-dose chemotherapy for breast cancer; Fisher DC et al.; Five hundred and eighty-one patients with stage II-IV breast cancer were treated at Duke University Medical Center with high-dose chemotherapy, followed by hematopoietic support . All patients received a conditioning regimen of cyclophosphamide, cisplatin and carmustine . Of these patients, 15 (2.6%) developed symptoms similar to the hemolytic-uremic syndrome with evidence of thrombotic microangiopathy (TMA) . The time of onset ranged from 75 days to 281 days post-transplant, with a median of 143 days . Hemolytic anemia and thrombocytopenia, without alternative cause, were required for diagnosis . All patients were treated with steroid therapy . In addition, 12 patients were treated primarily with plasmapheresis, and received a median of 46 treatments . Additional therapy included staphylococcal protein A column apheresis (eight patients), vincristine (three patients) and danazol (one patient) . The mortality rate was 11 of 15 patients (73%) . These patients had a median survival of 41 days from diagnosis of TMA (range 2-76 days) . The four survivors are alive at 76, 186, 1837 and 2387 days from diagnosis of TMA . Three of these patients received twice daily plasmapheresis and protein A column apheresis therapy . One patient recovered without specific therapy . TMA is an infrequent complication of high-dose chemotherapy, but is associated with a high mortality . It frequently follows significant pulmonary drug toxicity . Survival may be improved with early diagnosis and aggressive plasmapheresis therapy.

Cancer Immunol Immunother, 1996 Jul, 42(6), 369 - 75
Further characterization of cytotoxic T cells generated by short-term culture of human peripheral blood lymphocytes with interleukin-2 and anti-CD3 mAb; Jacobs N et al.; In this study we have specifically investigated the participation of T cells in the cytotoxic activity of peripheral blood lymphocytes (PBL) activated by interleukin-2 (IL-2, 50 U/ml) alone or in combination with an anti-CD3 mAb (BMA030, 10 ng/ml, IgG2a) . Purified CD3+ T cells, incubated in the presence of the anti-CD3 mAb for 4 days, mediated a cytotoxic activity against HL60 and U937 tumor cell lines . Several findings suggested the involvement of a redirected-cytotoxicity phenomenon, since the lytic process was restricted to target cell lines bearing the high-affinity Fc gamma receptor (Fc gamma RI) and T lymphocytes stimulated by IL-2 alone did not lyse these cell lines . Furthermore, anti-CD3 mAb F(ab')2, anti-CD3 IgG1 (UCHT1), phytohemagglutinin or staphylococcal enterotoxin A did not induce a similar cytotoxic activity in T lymphocytes . The cytotoxic process occurred in the presence of a very low level of anti-CD3 antibodies (in the nanomolar range) . The cytotoxic activity of T cells stimulated by IL-2 or by IL-2 + BMA030, against OVCAR-3 cells (MOv18+ ovarian tumor cell line), was also compared in the presence of a bispecific antibody OC/TR, anti-CD3 x MOv18) . The stimulation by IL-2 + BMA030 induced approximately a twofold higher cytotoxic activity than IL-2-activated T cells . This could be related to the state of activation of effector cells stimulated by IL-2 + BMA030, since the phenotypic analysis showed an increased proportion of T cells expressing several activation/differentiation markers (CD25, HLA-DR, CD45R0, adhesion molecules) . These findings could be applied to the design of therapeutic protocols using anti-CD3 x antitumoral bispecific antibodies.

Kidney Int, 1996 Jul, 50(1), 290 - 7
Induction of glomerulonephritis in rats with staphylococcal phosphatase: new aspects in post-infectious ICGN; Yousif Y et al.; Staphylococcal neutral phosphatase (NPtase) is a highly cationic bacterial surface bound protein . It has significant affinity for human and rat immunoglobulins in vitro and an electrostatic interaction may be involved . Radioisotopic studies showed that NPtase had a high affinity for the polyanionic structures of the rat renal glomerulus . When the left kidneys of germ-free or naive (non-immune) Wistar rats were perfused with 80 micrograms of I125 NPtase, 21 micrograms of NPtase were found in the left kidneys and 11 micrograms in the isolated glomeruli 15 minutes after perfusion . Deposits of autologous immunoglobulin and C3 were seen in the glomeruli of rats immediately after perfusion with NPtase (15 min) and persisted throughout the 14-day observation period . Histologically, neutrophil influx into the glomerulus was seen at 15 minutes and increased until three hours; subepithelial electron-dense deposits were found after three days and were still visible on day 14 . Proteinuria started within the first 24 hours despite the absence of an immune response at this time and was still present on day 14 . Similar results were observed in immune deficient athymic nude rats in the early phase . Perfusion of heparin after NPtase inhibited the deposition of IgG and C3 and prevented proteinuria in naive but not in actively immunized rats . This result provides further evidence that specific antibodies to NPtase were not involved in the immune complex-like deposits seen in the early phase . NPtase is a novel molecule, as it reveals both high affinity for the GBM and binding of circulating immunoglobulins, by a non-antigen-antibody mechanism, to form IC-like deposits on the GBM . These deposits are capable of activating the complement system, thus triggering a series of events leading to glomerulonephritis . These results delineate an additional pathway for the pathogenesis of ICGN related to bacterial infection.

Immunology, 1996 Jul, 88(3), 441 - 6
Staphylococcal enterotoxin B-specific adhesion of murine splenic T cells to a human endothelial cell line; Kita M et al.; The presence of a putative autoantigen of autoimmune disorder in a target organ may cause accumulation of specific T cells in the inflammatory region . One of the mechanisms of such accumulation involves the migration of specific-circulating T cells through the endothelial cells into the target lesion . The presence of only a few specific T cells responsive to a putative autoantigen has hampered the investigation of specific migration of circulating T cells to the target organ . We used a superantigen to investigate specific T-cell adhesion to endothelial cells, because it stimulates a large proportion of T cells with particular V beta elements and adhesion of T cells to the endothelium is a vital step in the migration process . Adhesion of murine T cells to the human endothelial cell line, EA.hy926, was specifically increased in the presence of staphylococcal enterotoxin B (SEB) . The increase was interferon-gamma (IFN-gamma)-dependent, and consisted mainly of CD4+ T cells . V beta 8.1,2+ T cells preferentially adhered to endothelial cells in the presence of SEB compared with V beta 6+ T cells . Pretreatment of endothelial cells with SEB increased the adherence of V beta 8.1,2+ T cells, while anti-human leucocyte antigen (HLA)-DR and -DQ antibodies inhibited the increased adherence of V beta 8.1,2+ T cells . Our results demonstrate that increased T-cell adhesion to endothelial cells is SEB specific, and that the specificity is dependent on major histocompatibility complex (MHC) class II molecules expressed on endothelial cells and on the recognition of the SEB-MHC class II complex by V beta 8.1,2+ T cells.

Immunology, 1996 Jul, 88(3), 389 - 93
A sigma ligand, SR 31747A, potently modulates Staphylococcal enterotoxin B-induced cytokine production in mice; Bourrie B et al.; Sigma receptors originally described in distinct regions of the central nervous system are expressed on cells of the immune system . A sigma ligand, SR 31747A, was observed here to inhibit in vitro the Staphylococcal enterotoxin B (SEB)-driven lymphocyte proliferation . In mice, the drug confers a potent protection against the lethality induced by SEB, stimulates the SEB-induced serum release of interleukin (IL)-10 and inhibits at the same time the systemic release of IL-2, IL-4, granulocyte-macrophage colony-stimulating factor (GM-CSF), IL-6 and tumour necrosis factor-alpha (TNF-alpha) . The enhancement of IL-10 production by this compound is also effective in nude mice treated with SEB, indicating that IL-10 of T-cell origin is not involved in this process . The finding that a sigma ligand protects against the SEB-induced toxicity provides insights into the clinical use of this family of compounds, particularly in food poisoning and septic shock where Staphylococcal enterotoxins are involved . The observation that this compound stimulates IL-10 synthesis indicates that it could be a potent regulatory agent of chronic inflammatory diseases.

Eur J Immunol, 1996 Jul, 26(7), 1459 - 67
Mechanisms of peripheral T cell deletion: anergized T cells are Fas resistant but undergo proliferation-associated apoptosis; Miethke T et al.; The complementary receptor pair Fas ligand: Fas controls apoptosis during activation-induced cell death (AICD) of peripheral T cells sensitized for the Fas signal pathway by interleukin-2 (IL-2) . In the present study, we used the bacterial superantigen staphylococcal enterotoxin B (SEB) to anergize ligand-reactive peripheral T cells in wild-type and Fas-defective lpr mice . In a second step, we investigated whether apoptosis in anergized and thus operationally IL-2-defective peripheral T cells is triggered via the Fas signal pathway . We report here that SEB-driven anergy induction and deletion of anergized peripheral V beta 8+ T cells is similar in wild-type and healthy C3H/lpr mice . In monitoring SEB-driven V beta 8+ T cell apoptosis in situ, we observe in both wild-type and lpr mice an intimate association between proliferation and apoptosis of anergized V beta 8+ T cells . We further show that V beta 8+ T cells activated in vitro from wild-type mice express a Fas-sensitive phenotype determined by Fas cross-linking which causes apoptosis . In contrast, V beta 8+ T cells anergized in vivo from wild-type mice are Fas resistant . As expected, T cells from lpr mice activated in vitro or anergized in vivo are Fas resistant . Taken together, these data indicate that both in wild-type and Fas-defective C3H/lpr mice, anergized T cells become deleted via a Fas-independent, proliferation-associated apoptosis signal pathway.

Exp Toxicol Pathol, 1996 Jul, 48(5), 471 - 6
Immunotoxicology of T cell-dependent experimental liver injury; Tiegs G et al.; Microbial toxins as well as certain drugs and xenobiotics exert their toxic potential towards mammalian organisms by either activation or suppression of the immune system . We have investigated the immune stimulatory effect of either the bacterial superantigen staphylococcal enterotoxin B (SEB) or of the T cell activating anti-CD3 monoclonal antibody (alpha CD3-mAb) or of the T cell mitogenic plant lectin concanavalin A (Con A) in murine in vivo and in vitro systems . Any of these agents evoked a strong cytokine response in vitro and in vivo . Tumor necrosis factor-alpha (TNF) was identified as a common cytotoxic mediator which induced hepatocyte apoptosis as characterized by histological examination and internucleosomal DNA fragmentation, that preceded the release of liver specific enzymes into plasma and the histological appearance of necrosis . These mechanisms of acute liver failure observed under experimental conditions are discussed to account also for liver injury during acute episodes of autoimmune or viral hepatitis or rejection of liver grafts.

FEMS Microbiol Lett, 1996 Jul 1, 140(2-3), 253 - 9
Identification and analysis of a gene encoding a Fur-like protein of Staphylococcus epidermidis; Heidrich C et al.; A gene (fur) for a Fur-like protein was identified on a 1.1 kb chromosomal DNA fragment of Staphylococcus epidermidis BN 280; the fur gene is followed by an open reading frame coding for the N-terminus of a putative superoxide dismutase . Within the -35 promoter region of both genes, as sequence motif was detected with low similarity to Fur-binding regulatory DNA segments, the so-called Fur boxes . Fur titration in Escherichia coli strain H1717 demonstrated that the E . coli Fur protein binds to the Fur box of the promoter region of the S . epidermidis fur gene . The S . epidermidis Fur protein was expressed in E . coli as indicated by the formation of inactive dimers with the chimeric repressor CI(N)-Fur(C) (Stojiljkovic, I . and Hantke . K . (1995) Mol . Gen . Genet . 247, 199-205), but was not able to complement the Fur mutation in E . coli H1681.

Am J Physiol, 1996 Jul, 271(1 Pt 1), C61 - 73
Stimulation of gastric acid secretion by cAMP in a novel alpha-toxin-permeabilized gland model; Yao X et al.; It is generally believed that histamine-stimulated gastric acid secretion involves a transient elevation of intracellular Ca2+ and the adenosine 3',5'-cyclic monophosphate (cAMP)-dependent protein kinase (PKA) cascade through phosphorylation, whose actions ultimately effect the fusion of H(+)-K(+)-adenosinetriphosphatase (ATPase)-containing vesicles to the apical plasma membrane of parietal cells . To dissect the signaling events underlying gastric acid secretion, we have developed a permeabilized gastric gland model using Staphylococcus alpha-toxin . The advantage of this model is its ability to retain cytosolic components that are required for the secretory machinery . Here we show that acid secretion in alpha-toxin-permeabilized glands is a cAMP-dependent process, reaching a maximal stimulation at 100 microM cAMP . The cAMP-elicited acid secretion, as monitored by the accumulation of the weak base aminopyrine (AP), required functional mitochondria or exogenously supplied ATP . Maximal stimulation elicited by cAMP for AP uptake by permeabilized glands was 51-85% of intact glands . Moreover, secretory activity was potentiated by 0.1 mM ATP . The recruitment of H(+)-K(+)-ATPase-rich tubulovesicles into the apical plasma membrane was measured using biochemical and morphological assays, thus validating the cell activation processes in response to cAMP . From this permeabilized model, {gamma-32P}ATP was used to directly phosphorylate target proteins . A number of proteins whose phosphorylation-dephosphorylation is specifically modulated by cAMP were found . These studies establish the first permeabilized gland model in which the resting-to-secreting transition can be triggered and show that cAMP-mediated phosphorylation is correlated with secretory activity.

Kyobu Geka, 1996 Jul, 49(8 Suppl), 656 - 60
{Surgical-treatment for active infective endocarditis}; Yoshida M et al.; The results of surgical treatment of active native infective endocarditis in 24 patients were analyzed . Fifteen of 24 (63%) patients were successfully cured by operation . Three of the 8 patients with severe cardiac failure who underwent emergency operation died of low cardiac output syndrome and bleeding early postoperatively . One of the 6 patients with late death had preoperative cerebral embolism and died of multiple organ failure . Five of them had annular infection . Among 6 patients with annular infection, 3 patients who had Staphylococcus epidermidis and Gram negative bacterium as a causative microorganism had a short duration within 4 weeks from the onset to operation . Two died suddenly in the long-term period after surgery because of prosthetic valve detachment . The second operation were required for other 4 patients because of prosthetic valve endocarditis or perivalvular leakage . Three of them were lost from low cardiac output syndrome . These findings suggested that delayed surgical intervention may be a major causative factor resulting in high surgical mortality . For patients with active native infective endocarditis, an early aggressive operation should be considered prior to congestive heart failure and the destruction of the annulus.

J Virol, 1996 Jul, 70(7), 4800 - 4
A bispecific antibody recognizing influenza A virus M2 protein redirects effector cells to inhibit virus replication in vitro; Fernandez-Sesma A et al.; Bispecific antibodies can be used to redirect cytotoxic T cells to kill virus-infected cells, overriding the need for major histocompatibility complex restriction . We produced a bispecific antibody (3F12) which binds influenza virus M2 protein and the T-cell receptor and can redirect staphylococcal enterotoxin B-activated T cells to kill influenza virus-infected cells and inhibit virus replication in vitro.

J Virol, 1996 Jul, 70(7), 4329 - 37
Therapeutic effect of Gag-nuclease fusion protein on retrovirus-infected cell cultures; Schumann G et al.; Capsid-targeted viral inactivation is a novel protein-based strategy for the treatment of viral infections . Virus particles are inactivated by targeting toxic fusion proteins to virions, where they destroy viral components from within . We have fused Staphylococcus nuclease (SN) to the C-terminal end of Moloney murine leukemia virus Gag and demonstrated that expression of this fusion protein in chronically infected chicken embryo fibroblasts resulted in its incorporation into virions and subsequent inactivation of the virus particles by degradation of viral RNA . Release of particles incorporating Gag-SN fusion proteins into the extracellular milieu activates the nuclease and results in destruction of the virion from within . By comparing the effects of incorporated SN and SN*, an enzymatically inactive missense mutant form of SN, on the infectivity of virus particles, we have clearly demonstrated that nucleolytic activity is the antiviral mechanism . Expression of Gag-SN fusion proteins as a therapeutic agent causes a stable reduction of infectious titers by 20- to 60-fold . The antiviral effect of capsid-targeted viral inactivation in our model system, using both prophylactic and therapeutic approaches, suggests that a similar anti-human immunodeficiency virus strategy might be successful.

Arterioscler Thromb Vasc Biol, 1996 Jul, 16(7), 868 - 77
Uptake of vWF-anti-vWF complexes by platelets in suspension; White JG et al.; Efforts to identify the translocation of glycoprotein (GP) Ib/IX receptors, either bound to von Willebrand factor (vWF) or not, from exposed surfaces to interior membranes of thrombin-activated platelets in suspension have been unsuccessful . To observe vWF uptake by platelets, we added an anti-vWF antibody and staphylococcal protein A-gold (to act as a marker for the antibody) to an incubation medium containing washed platelets and bovine plasma vWF or ristocetin-activated human vWF . Thin sections of platelets incubated for 10, 20, or 30 minutes with vWF but without antibody revealed no internalization and minimal changes in the original discoid form . Over the same 30-minute period with anti-vWF, however, GPIb/IX-vWF-anti-vWF complexes were cleared from cell exteriors to channels of the open canalicular system . Engorgement of the open canalicular system with vWF multimers resulted in changes in shape, internal transformation, and degranulation . Physical changes associated with anti-vWF-induced uptake of vWF are not seen in platelets that are involved in hemostatic plug formation or clot retraction.

Biochem Biophys Res Commun, 1996 Jun 25, 223(3), 565 - 71
A neutralizing epitope of the superantigen SEA has agonist activity on T cells; Hobeika AC et al.; We have previously shown that sequence 121-149 of the staphylococcal enterotoxin superantigen SEA plays an important role in superantigen function . A synthetic peptide of this region, SEA(121-149), blocks SEA binding to class II MHC molecules and induces interleukin-1 and tumor necrosis factor production in monocytes . In this study, we further emphasize the structural and functional significance of this region of SEA by showing that the SEA(121-149) peptide induces T cell proliferation in a manner similar to that of SEA . SEA(121-149) reacted with antibodies produced to SEA, and the SEA(121-149) specific antibodies neutralized SEA mitogenic activity . A tetrameric form of SEA(121-149) showed increased binding to antibodies and enhanced T cell activation, consistent with the greater avidity associated with increased valency . These data suggest that the internal domain of SEA corresponding to residues 121-149 plays an important role in superantigen activity.

Orv Hetil, 1996 Jun 23, 137(25), 1355 - 8
{The use of teicoplanin for Gram-positive infections in patients with kidney transplantation}; Jakics J et al.; Teicoplanin was used for the treatment of multiresistant Gram-positive-Staphylococcus aureus, coagulase negative Staphylococcus and Enterococcus-infections in 15 cases of kidney transplantations . The motive of the application was the once per day dosage and the spare of the transplanted kidney . Nosocomial infections were the most common . Clinical and microbiological diagnosis was the criteria in order to begin the 5-21 days treatment . These patients which were infected with Gram positive bacteria, teicoplanin was also effective in methicillin-resistant cases . In some mixed infections, after several courses of antibiotics, teicoplanin even if combined with other antibiotics could not prevent fatal sepsis.

Biochemistry, 1996 Jun 18, 35(24), 8084 - 94
Thermodynamics of the unfolding and spectroscopic properties of the V66W mutant of Staphylococcal nuclease and its 1-136 fragment; Eftink MR et al.; Spectroscopic studies have been performed to characterize the solution structure of the V66W mutant of Staphylococcal nuclease and the corresponding 1-136 fragment, referred to as V66W' . Whereas wild-type nuclease has a single tryptophan residue at position 140, the V66W mutant has a second tryptophan residue at position 66, which is the only such residue in V66W' . Steady-state and time-resolved fluorescence studies show Trp-66 in V66W' to have a blue emission, a relatively large fluorescence quantum yield, a long lifetime, a significant degree of protection from solute quenchers, and to depolarize with a relatively long rotational correlation time . These results characterize Trp-66 in V66W' as being a buried residue, which indicates that this fragment retains some global structure . Circular dichroism (CD) data are consistent with the fragment having lost most of the alpha-helical content of the wild type, while retaining beta-sheet structure . The CD spectrum in the aromatic region also suggests that Trp-66 in the fragment experiences an asymmetric environment, which is not identical to that in the full length mutant, V66W . In addition, optical detection of triplet state magnetic resonance (ODMR) spectroscopy can clearly resolve the tryptophan residues and demonstrates differences between the local environment of Trp-66 in V66W and in V66W', as well as small differences in the Trp-140 environment in wild type and in V66W . Guanidine-HCl induced and thermally induced unfolding studies were performed by simultaneously acquiring CD and fluorescence data as a function of the perturbation and then performing a global analysis of such multiple data sets in terms of two-state and three-state unfolding models . Whereas data for wild-type nuclease and the V66W' fragment are well characterized by a two-state unfolding model, data for the V66W mutant are better characterized by a three-state process . That is, both the denaturant- and temperature-induced unfolding of V66W involves the significant population of an equilibrium unfolding intermediate . Our global analyses yield thermodynamic parameters for the unfolding transitions, and we show that the data for V66W can be described by a constrained three-state model in which the transition of the intermediate to the fully unfolded state is fixed to have the same thermodynamic parameters that describe the unfolding of the V66W' fragment.

J Immunol, 1996 Jun 15, 156(12), 4602 - 8
In vivo T cell response to viral superantigen . Selective migration rather than proliferation; Le Bon A et al.; Superantigens induce T cell activation and proliferation in vitro, and some also induce cell activation in vivo . MMTV(SW) is an infectious mouse mammary tumor virus (MMTV) encoding a superantigen with the same Vbeta specificity as MIs-1a (Mtv-7), which induces a strong local response in vivo . injection of MMTV(SW) into mouse footpads leads to accumulation of superantigen-reactive T cells (Vbeta6+CD4+) and B cells in the draining lymph nodes (LN) . We investigated the kinetics of this cell accumulation by measuring cell activation (blastogenesis, CD25 and CD69 expression), cell migration (using syngenic FITC-labeled CD4+ cells and L-selectin detection), and cell proliferation (using in vivo labeling with bromodeoxyuridine) . Specific T cells selectively migrated to the draining LN . Accumulating Vbeta6+CD4+ T cells were large CD69+ cells, but remained CD25 negative and showed down-regulated L-selectin expression . Their DNA synthesis rate, studied by pulse labeling and continuous administration of bromodeoxyuridine, was increased, but remained too low to explain the draining LN hyperplasia . These data show that the local T cell response to MMTV(SW) mainly consists of selective migration followed by local activation of reactive T cells, and that cell proliferation is only a minor component of the response . By contrast, the optimal dose of staphylococcal enterotoxin B that, nevertheless, leads to a lower reactive T cell accumulation in the draining LN induces a very high proliferation rate.

Presse Med, 1996 Jun 8, 25(20), 944 - 50
{Nosocomial pneumonia}; Jebrak G et al.; Second cause of nosocomial infections and certainly the most serious, pneumonia concerns nearly 1% of all hospitalized patients . The need for intensive care, especially mechanical ventilation, is the leading risk factor for acquiring nosocomial pneumonia . Clinical and radiological data are contributive but insufficient for diagnosis and correct selection of antibiotics . Many germs are potentially accountable for these diseases, especially Pseudomonas and Staphylococcus . The endobronchial protected brush has been considered as the gold standard for diagnosis by the fifth consensus report of SRDLF (Societe de Reanimation de Langue Francaise) . Other methods are currently proposed which are less traumatic, cheaper, easier to use and give quicker results, but their sensitivity and specificity are debated . The bacteriological results of these searches are precious guides to choose curative antibiotics . The prevention of nosocomial pneumonia has become an accepted priority for public health.

Mech Ageing Dev, 1996 Jun 7, 87(2), 99 - 114
Termination by early deletion of V beta 8 + T cells of aged mice in response to staphylococcal enterotoxin B; Hosono M et al.; The changes in the T cell repertoire of aging BALB/c mice include an increase of V beta 8 + T cells, most of which have a relatively low density of T cell receptors (TCR) . We investigated the response of V beta 8 + T cells to staphylococcal enterotoxin B (SEB), a superantigen from a common bacterium, the anamnestic response to which is thought usually to be part of the defense against infection . The injection of an amount of SEB optimum for V beta 8 + T cell proliferation in young mice induced little or no proliferative response in aged mice, and within one or two days they died in shock with apoptotic cells in the spleen, a sign of T cell-shock caused by SEB . Flowcytometry analysis (FCA) 15 h after SEB injection, when cell division had not yet started, revealed the loss of 90% of V beta 8 + T cells in the blood and of 50% in the spleen in mice of all ages tested . However, conspicuous in the remaining V beta 8 + T cells in the spleens of the young mice but not in those of the aged mice, was an increased cellular complexity, as shown by the fact that light was strongly side scattered in FCA, indicating intracellular re-organization . The remaining T cells in the young could include progenitors for the expanding population of V beta 8 + T cells . As seen in lethal shock, V beta 8 + T cells in the aged are not unresponsive to SEB in vitro . They responded to the antigen by increasing the amount of TCR up to the level of that in young mice, but without proliferation . The proliferation arrest of V beta 8 + T cells of aged mice was found to be an intrinsic defect in in vitro cell mixture experiments, in which they were cocultured with young spleen cells which provided a complete immune microenvironment . It was simultaneously found in vitro that most of the V beta 8 + T cells from aged mice disappeared after antigen stimulation and that their disappearance was prevented by the presence of spleen cells from young mice, although they still did not proliferate . Taken all together the findings suggest that V beta 8+ T cells in the aged are at the end state of maturation and terminate by apoptotic death, causing T-cell shock in response to SEB.

Gastroenterology, 1996 Jun, 110(6), 1683 - 95
Interleukin 4 in inflammatory bowel disease and mucosal immune reactivity; West GA et al.; BACKGROUND & AIMS: Interleukin (IL) 4 has immunoregulatory and anti-inflammatory activities, but little is known about IL-4 in the human gut . We investigated production of IL-4 by isolated lamina propria mononuclear cells (LPMCs) from normal and inflamed intestine and its capacity to modulate local immune responses . METHODS: IL-4 levels were measured by enzyme-linked immunosorbent assay in cultures of control and inflammatory bowel disease LPMCs, and the effect of IL-4 on LPMC proliferation and interaction with IL-2, IL-1 beta, lipopolysaccharide, bacterial antigens, superantigen, and antibodies to various T-cell receptors was investigated . RESULTS: Various stimuli induced LPMCs to produce IL-4, but inflammatory bowel disease cells expressed IL-4 messenger RNA and secreted protein in significantly lower amounts than control cells . IL-4 failed to stimulate proliferation by fresh LPMCs, but a vigorous dose-dependent response was observed after preactivation by phytohemagglutinin, IL-2, or IL-4 . When added to fresh LPMCs, IL-4 inhibited IL-2-induced proliferation . IL-4 amplified proliferation to IL-1 beta, lipopolysaccharide, peptidoglycan-polysaccharide complexes, staphylococcus enterotoxin A, and antibodies to the CD3 and CD28 receptors but not to tetanus toxoid . CONCLUSIONS: Decreased production of IL-4 in inflammatory bowel disease may cause defective immunosuppressive and anti-inflammatory mechanisms and may contribute to disease pathogenesis . The ability of IL-4 to differentially modulate LPMC reactivity probably influences mucosal immune homeostasis.

Pharmacology, 1996 Jun, 52(6), 377 - 86
The effect of SM-8849 on experimental arthritis in mice; Nagai H et al.; The effect of a novel thiazole derivative, SM-8849, on experimental arthritis in mice was studied and compared to that of prednisolone . SM-8849 and prednisolone reduced the incidence and severity of type II collagen-induced arthritis in mice, as assayed by clinical observation and histopathological studies . Although both agents inhibited type II collagen-induced delayed type hypersensitivity (DTH) in arthritic mice, SM-8849 did not affect the production of humoral antibodies to type II collagen . To examine the inhibitory mechanism of SM-8849, the effects on T cell-dependent allergic inflammation were studied . SM-8849 clearly inhibited T cell-dependent reactions including staphylococcal enterotoxin B (SEB)-induced arthritis, SEB-induced CD25 expression on T cells and sheep red blood cell (SRBC)-induced DTH reaction . SM-8849, however, had no effect on the production of humoral antibody forming cells in the spleen of mice immunized with SRBC . These results indicate that inhibition of type II collagen-induced arthritis by SM-8849 is mainly due to the inactivation of T cells that are related to DTH reaction.

In Vitro Cell Dev Biol Anim, 1996 Jun, 32(6), 322 - 8
Release of chromaffin granular content from staphylococcal enterotoxin B (SEB)-treated and -untreated PC12 cells; Hase T et al.; The release of chromaffin granular content from staphylococcal enterotoxin B (SEB)-treated and -untreated PC12 cells was studied by electron microscopy . The treatment of the cells with SEB at the concentration of 20 micrograms/ml caused marked increase of the chromaffin granules that either bound to the plasma membrane by the characteristic rods, measuring 15 to 20 nm in length and showing a tubular structure, or budded off at the free cell surface, surrounded by a layer of rod-containing cytoplasm and enclosed by the plasma membrane . The binding between the granular and plasma membranes by the rods did not lead to membrane fusion and exocytosis of the granular content . Many of the bound granules showed vesiculation with loss of the electron-dense core material; at the same time, some of the binding rods contained intraluminal electron-dense material similar to the granular core material . These findings suggested that the electron-dense material (i.e., norepinephrine) of the bound granules was released extracellularly through channels within the rods . Although the granules were bound to the plasma membrane with equal frequency at the free and contiguous cell surfaces, the granular budding occurred only at the free cell surface, indicating that it occurred incidentally to some granules bound at the free cell surfaces . On the basis of the morphological observations, it is postulated that the electron-dense material of the bound granule is selectively released extracellularly through the rods, leaving the vesiculated granules behind in the cytoplasm . The same mode of release of the granular content was observed, though less frequently, in the untreated control cells . No morphological evidence that indicated that the granular content was released extracellularly by exocytosis was found in the treated and control cells . The present observations indicated that the SEB treatment of PC12 cells stimulated the binding of chromaffin granules to the plasma membrane by the rods and the budding of the bound granules at the free cell surface.

Intern Med, 1996 Jun, 35(6), 478 - 81
Syndrome of inappropriate secretion of antidiuretic hormone in elderly patients with rheumatoid arthritis associated with infections: report of two cases; Furuta E et al.; Two rheumatoid arthritis (RA) patients with the syndrome of inappropriate secretion of antidiuretic hormone (SIADH) during the course of infection are herein reported . One patient developed SIADH during the course of a localized cutaneous herpes zoster infection while the other developed SIADH in conjunction with Staphylococcus simulans septicemia . We consider that the development of SIADH was strongly associated with superimposed infections in the underlying RA . This is the first report discussing the association of SIADH and infections in RA patients in which SIADH is diagnosed by measurement of plasma ADH.

Biochem Mol Biol Int, 1996 Jun, 39(3), 521 - 7
Phosphorylation of different human milk proteins by human catalytic secretory immunoglobulin A; Kit YYa et al.; The ability of secretory immunoglobulin A (slgA) from milk of healthy mothers to phosphorylate various milk proteins in the presence of gamma-{32P}-ATP was shown to be a property of the antibodies . The polyclonal slgA was purified by sequential chromatography on Protein-A Sepharose and DEAE-cellulose, and then separated by chromatography on the ATP-Sepharose . The preparations containing all milk proteins except for protein kinases {integrated milk proteins (IMP)} were obtained by extraction of the kinase activities from the milk using their affinity to the insoluble crosslinked staphylococcus . Addition of slgA fractions (having a different affinity to ATP) to the IMP led to phosphorylation of casein and several other milk proteins with different efficiencies.

Biochem Mol Biol Int, 1996 Jun, 39(3), 487 - 92
Expression of cecropin CMIV fusion protein in E . coli under T7 promoter; Xie W et al.; A synthetic gene coding for cecropin CMIV from Bombyx mori was cloned into plasmid pEZZ318 and fused to a DNA segment encoding the signal peptide of Staphylococcal protein A and IgG binding domain . The fusion gene was then subcloned into expression vector pET11c under the control of T7 promoter and expressed in E . coli . The fusion protein did not exhibit any antibacterial activity either in cell lysate or in medium . After cleavage from the fusion protein with CNBr the biological activity of recombinant cecropin CMIV was obtained.

Inflamm Res, 1996 Jun, 45(6), 293 - 8
The effects of mesoporphyrin on experimental arthritis in mice; Nagai H et al.; The effects of mesoporphyrin, a novel porphyrin derivative, on type II collagen-induced arthritis in mice were studied . Mesoporphyrin (10-30 mg/kg) and prednisolone (5 mg/kg; reference drug) reduced the incidence and severity of type II collagen-induced arthritis in mice, as assayed by clinical observation and histopathological studies . Although both agents inhibited type II collagen-induced delayed type hypersensitivity in arthritic mice, only prednisolone inhibited humoral immunity to type II collagen . The effects of mesoporphyrin on T cell dependent allergic inflammation were examined, in order to study the mechanism by which it inhibits arthritis . Staphylococcal enterotoxin B (SEB; superantigen)-potentiated collagen-induced arthritis and sheep red blood cell-induced delayed type hypersensitivity reaction were clearly inhibited by mesoporphyrin . Moreover, the superantigen-induced CD-25 expression on T cells was inhibited by mesoporphyrin . These results indicate that mesoporphyrin inhibits type II collagen-induced arthritis by inhibiting the activation of T cells.

Bone Marrow Transplant, 1996 Jun, 17(6), 1093 - 9
Autoimmune hemolytic anemia following T cell-depleted allogeneic bone marrow transplantation; Drobyski WR et al.; The development of immune-mediated hemolytic anemia is a well-recognized complication after allogeneic bone marrow transplantation (BMT) . The majority of reported cases, however, have been alloimmune in origin due to ABO or minor red blood cell antigen incompatibilities between the donor and recipient . In this study, we report seven adult patients who developed autoimmune hemolytic anemia (AIHA) between June 1985 and January 1993 . These patients were identified from a total of 236 adult patients who received T cell-depleted (TCD) grafts as graft-versus-host disease (GVHD) prophylaxis . The onset of AIHA was at a median of 10 months (range 7-25 months) post-transplant and occurred in 5% of all patients transplanted with TCD grafts who survived at least 6 months . Six patients had a warm reacting autoantibody, while one patient had a cold-reacting antibody with a thermal amplitude up to 30 degrees C . All were receiving immunosuppressive treatment for GVHD at the time of diagnosis . Initial treatment in all patients consisted of steroids . Three of the seven had a partial response while the four remaining patients failed to respond to corticosteroids . Splenectomy was performed in three patients with two partial responses . Four patients were treated with additional therapeutic interventions, including plasmapheresis, immunoglobulin infusions, staphylococcus protein A column, or other immunosuppressive agents . In five cases, erythropoietin was administered as adjunctive treatment to maintain adequate hematocrit levels . Two patients are presently in complete remission after prolonged courses of steroids, while a third patient has compensated hemolysis requiring low-dose steroids . Four patients died due to either infectious complications or disseminated intravascular coagulation secondary to cold agglutinin disease . These data indicate that AIHA is a clinically significant and not infrequent complication in allogeneic marrow transplant recipients . The response to conventional treatment is generally unsatisfactory as even patients who ultimately remit require prolonged courses of immunosuppressive therapy.

AIDS, 1996 Jun, 10(7), 729 - 37
Skewing of the T-cell receptor repertoire in the lung of patients with HIV-1 infection; Trentin L et al.; OBJECTIVES: A bias of the use of T-cell receptor (TCR) V beta regions has been reported both in peripheral blood and in several tissues in patients with AIDS, including lymph nodes, spleen and salivary glands . Although the disease is frequently characterized by an infiltration of T cells in the lung interstitium, no information is presently available on the configuration of the TCR repertoire in this microenvironment . This study was performed to address the question of whether a bias in T-cell selection occurs in the lung of patients with AIDS . METHODS: TCR beta-chain variable region (TCR-V beta) repertoire was analysed by flow cytometry and polymerase chain reaction (PCR) analyses in blood and lung lymphocytes of 13 patients with HIV-1 infection at different stages of the disease . Blood and lung lymphocytes were also assessed for their responsiveness to different superantigenic stimuli represented by staphylococcal enterotoxins (SEA, SEB, SEC1, SEC2, SED and SEE) . RESULTS: Flow cytometry analysis in AIDS patients demonstrated an overexpression of cells bearing V beta 2 and V beta 3 gene segments in the lung compared with peripheral blood of the same subjects, as well as to lung and blood lymphocytes of normal controls . PCR analysis performed in AIDS patients extended these observations and demonstrated a significant bias also in the use of T cells bearing V beta 7 and V beta 9 gene regions in the lung compartment with respect to the blood . Virtually all T cells bearing the overrepresented V beta segment belong to the CD8 subset . Interestingly, T-lymphocyte response to different superantigens demonstrated a low proliferative rate in the lung with respect to the blood in HIV-1-infected patients . CONCLUSIONS: These findings indicate a compartmentalization of cells bearing discrete V beta gene products in the pulmonary microenvironment of patients with AIDS and suggest that the expansion of specific-V beta region subsets occurring in the lung might result from triggering by a superantigen.

Vet Immunol Immunopathol, 1996 Jun 1, 51(3-4), 225 - 33
Restriction fragment length polymorphism of the T-cell receptor beta-chain gene in dogs; Tipold A et al.; Since T-cells and the T-cell receptor (TCR) play a pivotal role in the response of the immune system, they are a target for pathogenesis studies in immune mediated diseases and have been used to generate markers for T-cell dependent diseases in humans and dogs . TCR rearrangement is generated at the genomic DNA level and can be analyzed by Southern blotting techniques . In the present study this method to detect rearrangement of the TCR beta chain in the dog was critically examined . To search for restriction fragment length differences due to either inherited polymorphism or in diseases with suspected superantigen influence (X-linked severe combined immune deficiency and canine juvenile polyarteritis syndrome) 13 dog families of three different breeds were examined . In addition primary spleen cell cultures, stimulated with either phytohemagglutinin A (PHA) or staphylococcus enterotoxin A (SEA) and B (SEB) were studied . The germline digest pattern of the enzymes Pst I, Sst I, Bgl II, Eco RI and Eco RV were identical in all dogs examined with the exception of one dog with canine juvenile polyarteritis syndrome . In this dog an additional band was found in the Bgl II and Eco RV digestion suggestive of specific TCR rearrangement . Bam HI digestion revealed restriction fragment length polymorphisms (RFLPs) showing Mendelian inheritance . After digestion of the genomic DNA extracted from PHA, SEA or SEB stimulated spleen cells and Southern blot analysis, no differences in fragment patterns between the unstimulated cells and the stimulated cells could be detected . An important point to consider before a specific pattern variation between dogs is classified to be a marker for a specific disease or is used in pathogenesis studies, is the possibility of an inherited RFLP, especially after Bam HI digestion . In such studies the combined examination of the parents and the offspring must be recommended.

Z Gastroenterol, 1996 Jun, 34(6), 378 - 81
{Abscess development caused by ingrown nitinol spiral as a fatal complication of a partially deteriorated MEMOSOND-PEG}; Gossner L et al.; Percutaneous endoscopic gastrostomy (PEG) is a safe method with a low complication rate for providing enteral nutrition . While the "pull" method is the standard technique for PEG placement, alternatively "push" methods were developed in order to minimize peristomal wound infections caused by micro-organisms from the oropharyngeal cavity . Intragastral fixation of the "push" type PEG tube has always been a problem . The MEMOSOND-PEG uses a heat activated nitinol memory spiral as an anchor-like intragastral fixation . So far, an intraabdominal dislocation and a perforation have been reported as severe complications of this type of PEG tube . Five years after insertion we observed the development of an abscess induced by ingrowth of a nitinol spiral into the stomach wall as a further fatal complication in a patient with a MEMOSOND-PEG . The memory metal spiral had pierced the stomach wall after partial destruction of the polyurethane covering . The nitinol spiral was endoscopically extracted in several fragments . Ten days after extraction however, the patient died of combined kidney and liver failure due to a sepsis with Staphylococcus.

Protein Sci, 1996 Jun, 5(6), 1026 - 31
Mobile unnatural amino acid side chains in the core of staphylococcal nuclease; Wynn R et al.; The structures of several variants of staphylococcal nuclease with long flexible unnatural amino acid side chains in the hydrophobic core have been determined by X-ray crystallography . The unnatural amino acids are disulfide moieties between the lone cysteine residue in V23C nuclease and methane, ethane, 1-n-propane, 1-n-butane, 1-n-pentane, and 2-hydroxyethyl thiols . We have examined changes in the core packing of these mutants . Side chains as large as the 1-n-propyl cysteine disulfide can be incorporated without perturbation of the structure . This is due, in part, to cavities present in the wild-type protein . The longest side chains are not well defined, even though they remain buried within the protein interior . These results suggest that the enthalpy-entropy balance that governs the rigidity of protein interiors favors tight packing only weakly . Additionally, the tight packing observed normally in protein interiors may reflect, in part, the limited numbers of rotamers available to the natural amino acids.

Protein Sci, 1996 Jun, 5(6), 991 - 1000
Protein folding for realists: a timeless phenomenon; Shortle D et al.; Future research on protein folding must confront two serious dilemmas . (1) It may never be possible to observe at high resolution the very important structures that form in the first few milliseconds of the refolding reaction . (2) The energy functions used to predict structure from sequence will always be approximations of the true energy function . One strategy to resolve both dilemmas is to view protein folding from a different perspective, one that no longer emphasizes time and unique trajectories through conformation space . Instead, free energy replaces time as the reaction coordinate, and ensembles of equilibrium states of partially folded proteins are analyzed in place of trajectories of one protein chain through conformation space, either in vitro or in silico . Initial characterization of the folding of staphylococcal nuclease within this alternative conceptual framework has led to an equilibrium folding pathway with several surprising features . In addition to the finding of two bundles of four hydrophobic segments containing both native and non-native interactions, a gradient in relative stability of different substructures has been identified, with the most stable interactions located toward the amino terminus and the least stable toward the carboxy terminus . Hydrophobic bundles with up-down topology and stability gradients may be two examples of numerous tactics used by proteins to facilitate rapid folding and minimize aggregation . As NMR methods for structural analysis of partially folded proteins are refined, higher resolution descriptions of the structure and dynamics of the polypeptide chain outside the native state may provide many insights into the processes and energetics underlying the self-assembly of folded structure.

J Biomed Mater Res, 1996 Jun, 31(2), 149 - 55
Staphylococcus epidermidis adhesion to films deposited from hydroxyethylmethacrylate plasma; Morra M et al.; The adhesion of S . epidermidis ATCC 35984 strain on polystyrene (PS) disks coated by films deposited from hydroxyethylmethacrylate (HEMA) plasma was evaluated and compared to adhesion on untreated PS and oxygen-plasma-treated PS . Films were deposited keeping constant the monomer flow rate while the discharge power ranged from 40-100 W in order to obtain coating with different surface properties . Surface chemistry, energetics, and morphology were evaluated by Electron Spectroscopy for Chemical Analysis (ESCA), contact angle measurement, and Atomic Force Microscopy (AFM), respectively . Bacteria adhered more to the plasma-deposited or plasma-treated surfaces than to untreated PS, but no significant difference was recorded among the samples obtained using different deposition conditions . According to the surface energetic analysis, plasma-deposited and plasma-treated surfaces bear a strong Lewis-base character, so it is possible to hypothesize a marked contribution of electron donor-electron acceptor interactions to the mechanism(s) controlling adhesion between synthetic and bacterial surfaces.

Neth J Med, 1996 Jun, 48(6), 227 - 31
Vertebral bone destruction in sickle cell disease: infection, infarction or both; Kooy A et al.; Infectious and vaso-occlusive vertebral bone and joint destruction in two patients with sickle cell disease (SCD) are featured by H-shaped vertebrae, kyphotic angulation, osteolysis of endplates and collapse of intervertebral discs as shown by X-ray films and magnetic resonance imaging . Staphylococcal serology supported the diagnosis of staphylococcal osteomyelitis/spondylo-discitis in both SCD patients . The difficulties of establishing the causes and treatment of the osteoarthropathy in these particular cases are discussed in the light of the literature.

J Exp Med, 1996 Jun 1, 183(6), 2481 - 8
Induction of unresponsiveness and impaired T cell expansion by staphylococcal enterotoxin B in CD28-deficient mice; Mittrucker HW et al.; We used CD28-deficient mice to analyze the importance of CD28 costimulation for the response against Staphylococcal enterotoxin B (SEB) in vivo . CD28 was necessary for the strong expansion of V beta 8+ T cells, but not for deletion . The lack of expansion was not due to a failure of SEB to activate V beta 8+ T cells, as V beta 8+ T cells from both CD28-/- and CD28+/+ mice showed similar phenotypic changes within the first 24 h after SEB injection and cell cycle analysis showed that an equal percentage of V beta 8+ T cells started to proliferate . However, the phenotype and the state of proliferation of V beta 8+ T cells was different at later time points . Furthermore, in CD28-/- mice injection with SEB led to rapid induction of unresponsiveness in SEB responsive T cells, indicated by a drastic reduction of proliferation after secondary SEB stimulation in vitro . Unresponsiveness could also be demonstrated in vivo, as CD28-/- mice produced only marginal amounts of TNF alpha after rechallenge with SEB . In addition CD28-/- mice were protected against a lethal toxic shock induced by a second injection with SEB . Our results indicate that CD28 costimulation is crucial for the T cell-mediated toxicity of SEB and demonstrate that T cell stimulation in the absence of CD28 costimulation induces unresponsiveness in vivo.

Infect Immun, 1996 Jun, 64(6), 2322 - 30
Molecular cloning and sequence analysis of the gene encoding LipL41, a surface-exposed lipoprotein of pathogenic Leptospira species; Shang ES et al.; We report the cloning of the gene encoding a surface-exposed leptospiral lipoprotein, designated LipL41 . In a previous study, a 41-kDa protein antigen was identified on the surface of Leptospira kirschneri (D . A . Haake, E . M . Walker, D . R . Blanco, C . A . Bolin, J . N . Miller, and M . A . Lovett, Infect . Immun . 59:1131-1140, 1991) . We obtained the N-terminal amino acid sequence of a staphylococcal V8 proteolytic-digest fragment in order to design an oligonucleotide probe.A Lambda ZAP II library containing EcoRI fragments of L . kirschneri DNA was screened, and a 2.3-kb DNA fragment which contained the entire structural lipL41 gene was identified . The deduced amino acid sequence of LipL41 would encode a 355-amino-acid polypeptide with a 19-amino-acid signal peptide, followed by an L-X-Y-C lipoprotein signal peptidase cleavage site . A recombinant His6-LipL41 fusion protein was expressed in Escherichia coli in order to generate specific rabbit antiserum . LipL41 is solubilized by Triton X-114 extraction of L . kirschneri; phase separation results in partitioning of LipL41 exclusively into the detergent phase . At least eight proteins, including LipL41 and the other major Triton X-114 detergent phase proteins, are intrinsically labeled during incubation of L . kirschneri in media containing {3H} palmitate . Processing of LipL41 is inhibited by globomycin, a selective inhibitor of lipoprotein signal peptidase . Triton X-100 extracts of L . kirschneri contain immunoprecipitable OmpL1 (porin), LipL41, and another lipoprotein, LipL36 . However, in contrast to LipL36, only LipL41 and OmpL1 were exposed on the surface of intact organisms . Immunoblot analysis of a panel of Leptospira species reveals that LipL41 expression is highly conserved among leptospiral pathogens.

FEMS Microbiol Lett, 1996 Jun 1, 139(2-3), 149 - 53
The arsenical resistance operon of IncN plasmid R46; Bruhn DF et al.; The arsenical resistance operon of the IncN plasmid R46 consists of 4696 bp and starts with predicted transcriptional control and initiation signals, followed by five genes, arsD, arsA, and arsC . The corresponding Escherichia coli chromosomal ars operon and two staphylococcal ars operons lack arsA and arsD genes . The R46 system contains only the second known versions of arsA and arsD, after those of plasmid R773 . Western blot analysis identified the R46 proteins using antibodies against R773 ArsA, ArsD and ArsR.

J Immunol, 1996 Jun 1, 156(11), 4100 - 6
TCR-independent activation of human CD4+ 45RO- T cells by anti-CD28 plus IL-2: Induction of clonal expansion and priming for a Th2 phenotype; Brinkmann V et al.; In this study we show that uncommitted human CD4+ CD45RA+ RO- CD25- CD71- HLA-DR- T cells can be primed for a Th2 phenotype before they encounter TCR signals and before they are exposed to IL-4 . We found that >99% of uncommitted T cells proliferated upon costimulation by immobilized anti-CD3 plus anti-CD28 mAbs and differentiated into pure Th1 cells . In contrast, uncommitted T cells did not respond to stimulation by either anti-CD3 or anti-CD28, or by IL-2 alone . Interestingly, 5% of uncommitted T cells proliferated efficiently in response to stimulation by immobilized anti-CD28 plus IL-2 (in the absence of TCR/CD3 signals) and differentiated into pure Th2 "precursor" cells . Like murine CD4+ NK1.1+ T cells, human Th2 precursors promptly expressed mRNA for Th2 cytokines upon stimulation via the TCR/CD3 complex by anti-CD3 mAb or staphylococcal enterotoxin B, and secreted up to 50 ng of IL-4, IL-5, and IL-13 per 10(6) cells . Th2 "precursors" developed only in the complete absence of IL-4, as addition of 0.1 U (5 pg) of exogenous IL-4 suppressed their clonal expansion by >90%, whereas addition of neutralizing anti-IL-4 mAb had no effect . Together these results suggest that, in vivo, a significant fraction of uncommitted T cells may be primed for a Th2 phenotype independent of Ag and IL-4 if they are exposed to Th1 cell-derived IL-2 and simultaneously interact with accessory cells bearing the natural CD28 ligands B7-1 and B7-2 . When stimulated by specific Ag, such primed Th2 precursor cells may provide a source of IL-4 to promote Th2 immunity.

Proc Natl Acad Sci U S A, 1996 May 28, 93(11), 5425 - 30
Differential effects of staphylococcal toxic shock syndrome toxin-1 on B cell apoptosis; Hofer MF et al.; Superantigens, such as toxic shock syndrome toxin 1 (TSST-1), have been implicated in the pathogenesis of several autoimmune and allergic diseases associated with polyclonal B cell activation . In this report, we studied the in vitro effects of TSST-1 on B cell activation . We show herein that TSST-1 produced antagonistic effects on Ig synthesis by peripheral blood mononuclear cells (PBMC) from normal subjects, depending on the concentration used; Ig production was inhibited at 1000 pg/ml (P < 0.01) and enhanced at 1 and 0.01 pg/ml (P < 0.01) of toxin . Cultures of PBMC were then examined for morphologic features and DNA fragmentation characteristic for apoptosis . B cells exhibited a significantly higher (P < 0.01) incidence of apoptosis after stimulation with 1000 pg/ml of TSST-1 compared with 1 or 0.01 pg/ml of toxin or medium alone . Abundant expression of Fas, a cell surface protein that mediates apoptosis, was detected on B cells after stimulation with 1000 pg/ml of TSST-1 and was significantly higher on B cells undergoing apoptosis than on live cells (P = 0.01) . Additionally, increased Fas expression and B cell death occurred at concentrations of TSST-1 inducing the production of high amounts of gamma interferon (IFN-gamma), and both events could be blocked by neutralizing anti-IFN-gamma antibody . These findings suggest that high concentrations of TSST-1 can induce IFN-gamma-dependent B cell apoptosis, whereas at low concentrations it stimulates Ig synthesis by PBMC from normal subjects . These findings support the concept that staphylococcal toxins have a role in B cell hyperactivity in autoimmunity and allergy.

Biochemistry, 1996 May 21, 35(20), 6443 - 9
Contributions of the ionizable amino acids to the stability of staphylococcal nuclease; Meeker AK et al.; To quantitate the contributions of the ionizable amino acids to the stability of the native state of staphylococcal nuclease, each of the 23 lysines, 5 arginines, 4 histidines, 12 glutamic acids, and 8 aspartic acids was substituted with both alanine and glycine . This collection of 104 mutant proteins was analyzed by guanidine hydrochloride (GuHCl) denaturation, using intrinsic tryptophan fluorescence to quantitate the equilibrium between native and denatured states . From the analysis of these data, each mutant protein's stability in the absence of denaturant (delta GH2O) and sensitivity to changes in denaturant concentration {mGuHCl = d(delta G)/d{GuHCl}} were obtained . Several general trends in these values suggest that electrostatic interactions make only a minor contribution to the net stability of this protein . For the residue pairs that form ten salt bridges and ten charged hydrogen bonds between side chains, no correlation was observed between the stability losses (delta delta G) accompanying alanine substitution of each member of the pair . Little or no significant correlation was found between the magnitude of the loss in stability and the local electrostatic potential calculated from the three-dimensional structure by numerical and model dependent solutions of the linearized Poisson-Boltzmann equation . The structural parameters which correlated most strongly with stability loss are measures of the extent of burial of the residue in the native structure, as was previously observed for alanine and glycine substitutions of large hydrophobic residues {Shortle et al . (1990) Biochemistry 29, 8033} and of the polar, uncharged residues {Green et al . (1992) Biochemistry 31, 5717} . These results suggest that the ionizable amino acids contribute to stability predominantly through packing and bonding interactions that do not depend on their electrostatic charge.

J Physiol, 1996 May 15, 493 ( Pt 1), 199 - 209
Ca2+ loading reduces the tensile strength of sarcolemmal vesicles shed from rabbit muscle; Nichol JA et al.; 1 . Sarcolemmal vesicles shed by rabbit muscle were loaded with Ca2+ by means of A23187 or ionomycin . {Ca2+}0 was buffered between 0.8 and 20 microM . Membrane strength was measured by pipette aspiration . 2 . At 20 microM Ca2+ many vesicles underwent autolysis, or were so weak that they burst instantly on aspiration . Between 10 and 2 microM Ca2+ a graded decrease in membrane strength was demonstrable . At 0.8 microM Ca2+ the mechanical properties of the sarcolemma remained unaltered . 3 . Mg2+ carried by A23187 does not mimic the effect of Ca2+ . The ionophore itself similarly did not cause a decrease in membrane tensile strength . 4 . Pre-treatment with BAPTA-AM, so as to buffer internal Ca2+, partly protected vesicles against the decrease in membrane strength produced by Ca2+ loading . 5 . Membrane strength was not restored by adding excess BAPTA to the bathing solution, so as to reverse the Ca2+ gradient . An irreversible degradation of the membrane consequent upon raised {Ca2+}1 seems indicated . 6 . These findings are discussed in relation to the mechanisms which have been advanced to account for the role of elevated {Ca2+}1 in cell death . 7 . An attempt to use staphylococcal alpha-toxin as an alternative means to permeabilize the sarcolemma led to the incidental finding that this pore-forming protein itself greatly weakens the membrane in doses lower than required for effective permeabilization.

Ann N Y Acad Sci, 1996 May 15, 782, 486 - 94
Chaperone-like effect during in vitro refolding of insulin-like growth factor I using a solubilizing fusion partner; Samuelsson E et al.; A fusion partner, ZZ, derived from staphylococcal protein A, has earlier been shown facilitate the in vitro folding of human insulin-like growth factor I (IGF-I) . Although no solubilizing agents were used, there was no problem with precipitation, even at relatively high protein concentrations . We have here investigated this phenomenon further by characterizing the in vitro refolding of IGF-I fused to one or two solubilizing Z domains . The comparison also included IGF-I without a solubilizing fusion partner . Solubility studies of the reduced proteins were performed, in addition to an evaluation of the aggregation occurring during the refolding process . Fusion to one or two Z domains increased the solubility of reduced IGF-I more than 100-fold . In addition, the Z or ZZ fusion partners decreased aggregation of the IGF-I moieties during the renaturation . The fusion partner has an effect resembling that of a cis-acting chaperone during in vitro refolding and may be an alternative to overcome the problems of insolubility and aggregation.

J Immunol, 1996 May 15, 156(10), 3668 - 77
Specific regulation of VLA-4 and alpha 4 beta 7 integrin expression on human activated T lymphocytes; Hernandez-Caselles T et al.; Modulation of VLA integrins was studied in several human T cell clones upon specific and nonspecific cellular activation . Human activated T lymphocytes down-regulated both alpha 4 beta 1 and alpha 4 beta 7 integrins upon specific recognition of alloantigens (cytotoxic T cells) or in the presence of Staphylococcus enterotoxin B (superantigen recognizing noncytotoxic T cells) . In contrast, the expression of other membrane integrins, such as VLA-1 and VLA-5 integrins, was not modified . Down-regulation of alpha 4 beta 1 and alpha 4 beta 7 integrins was observed as early as 3 h after stimulation, lasted later than 72 h and was partially inhibited by cytochalasin D . Interestingly, neither target cells nor NK cells modulated CD49d expression after interaction with T cells of K562, respectively, suggesting that CD49d expression was linked to specific T cell activation . The down-regulation of the CD49d chain in T cell clones stimulated with immobilized anti-CD3 mAbs confirmed the role of TCR-mediated activation in CD49d regulation . However, the CD3-independent cellular aggregation induced by soluble anti-CD43 mAb was also able to strongly down-regulate alpha 4 beta 1 and alpha 4 beta 7 . The present work shows the first evidence that CD49d subunit-bearing integrin expression is distinctly regulated from other integrins after Ag or superantigen recognition by human activated T cells . CD49d modulation may be relevant for the traffic and tissue localization of locally activated T cells during immune responses.

J Immunol, 1996 May 15, 156(10), 3608 - 20
Staphylococcal enterotoxin D functions as a human B cell superantigen by rescuing VH4-expressing B cells from apoptosis; Domiati-Saad R et al.; Staphylococcal enterotoxins are potent superantigens, in that they activate T cells bearing specific V beta-chain gene segments . In this study, we analyzed the capacity of staphylococcal enterotoxin D (SED) to function as a B cell superantigen . SED induced T cell-dependent polyclonal proliferation and differentiation of B cells . In the absence of T cells, SED induced survival of B cells uniquely expressing VH4 containing IgM . The mechanism of survival of VH4-expressing B cells appeared to relate to the countering of apoptosis initiated by the engagement of HLA-DR by SED . Analysis of the VH4 gene products expressed by SED-stimulated B cells revealed the usage of six of the known functional VH4 genes with a variety of different CDR3 regions, employing different DH and JH gene segments . Moreover, the sequence analysis identified a possible site for SED binding of VH4 that includes the solvent-exposed surfaces of 3' CDR2/FR3 and/or FR1 . Thus, SED appears to function as a unique B cell superantigen by inducing survival of VH4-expressing B cells.

Klin Lab Diagn, 1996 May-Jun, (3), 35 - 7
{Chemiluminescent reaction of leukocytes stimulated with different agents in patients with erysipelas}; Krasnova EI et al.; Forty-three patients with erysipelas and 10 donors were examined using chemiluminescent analysis in the presence of latex and staphylococcal reagent containing protein A . Staphylococcal protein A proved to be a more potent activator of oxygen metabolites than latex . Heterogeneity of chemiluminescent response of leukocytes stimulated by different agents makes it possible to assess the functional reserve of neutrophils and differentiate between the hyper-, normo-, and hyporeactive forms of erysipelas.

Zh Mikrobiol Epidemiol Immunobiol, 1996 May-Jun, (3), 71 - 4
{The resident staphylococcal bacterial carriage in a human population as an index for the microecological monitoring of its habitat environment}; Bukharin OV et al.; The informative character of staphylococcal persistence factors (antilysozyme and "anti-interferon" signs) as the indices of resident staphylococcal carrier state in the microecological monitoring of the aerial environment was determined . In areas, ecologically unfavorable with respect to the occurrence of diseases of respiratory organs and to the level of air pollution, staphylococcal strains with persistence factors were isolated from children 3 times as often as in areas with low levels of morbidity in respiratory diseases and environmental pollution . The background level resident staphylococcal carrier state was determined (8.1%), permitting the evaluation of the ecological loading and the mapping of the monitored territories.

J Antimicrob Chemother, 1996 May, 37(5), 881 - 9
pH modulation of aminoglycoside resistance in Staphylococcus epidermidis harbouring 6'-N-aminoglycoside acetyltransferase; Culebras E et al.; The kinetic constants of the aminoglycoside-modifying enzyme 6'-N-aminoglycoside acetyltransferase (AAC(6')IV) from the clinical strain Staphylococcus epidermidis RYC 13036 differed depending on whether tobramycin and amikacin (glycosamine group) or gentamicin and netilmicin (garosamine group) were used as substrates . Acetylation of the glucosamine antibiotics was highly susceptible to substrate inhibition which increased with pH whereas the garosamine group compounds showed limited substrate inhibition over a wide pH range . These differences in activity correlated with MIC values of S . epidermidis RYC 13036 for different aminoglycosides . Aminosugars moiety and pH markedly influenced the AAC(6')IV-aminoglycoside interactions.

Spine, 1996 May 1, 21(9), 1090 - 3
Retroperitoneal pseudomeningocele complicated by meningitis following a lumbar burst fracture . A case report; Nairus JG et al.; STUDY DESIGN . This case report demonstrates an unusual complication after anterior decompression and fusion of a lumbar burst fracture . OBJECTIVES . The treatment of this patient involved placement of a computed tomography-guided percutaneous drain and intravenous antibiotics to treat an infected retroperitoneal pseudomeningocele . SUMMARY OF BACKGROUND DATA . A case of an anterior retroperitoneal pseudomeningocele complicated by meningitis is presented . This pseudomeningocele occurred in a patient after an L3 burst fracture associated with a dural laceration . METHODS . The patient was admitted to the authors' trauma unit after a motor vehicle accident with an acute L3 fracture associated with incomplete paraplegia . He underwent an urgent anterior corpectomy, strut grafting, and instrumentation . At surgery, he was noted to have a large anterior dural laceration . After surgery, a large retroperitoneal pseudomeningocele developed that became infected with Staphylococcus epidermidis . RESULTS . After placement of a computed tomography-guided percutaneous drain and intravenous antibiotics, the pseudomeningocele resolved . His anterior fusion healed uneventfully and his neurologic deficit improved dramatically . CONCLUSIONS . A case of an anterior retroperitoneal pseudomeningocele complicated by meningitis is presented . This pseudomeningocele occurred in a patient after an L3 burst fracture associated with a dural laceration . The patient was treated successfully with computed tomography-guided percutaneous drain placement and intravenous antibiotics . He made an excellent functional recovery after a severe neurologic injury.

Antimicrob Agents Chemother, 1996 May, 40(5), 1242 - 7
Population pharmacokinetic study of teicoplanin in severely neutropenic patients; Lortholary O et al.; The teicoplanin pharmacokinetics (PK) of 30 febrile and severely neutropenic patients (polymorphonuclear count, < 500/mm3) with hematologic malignancies were compared with those determined for five healthy volunteers (HV) . Neutropenic patients were given piperacillin combined with amikacin, and teicoplanin was added to the regimen the day fever developed in patients suspected of having a staphylococcal infection or 48 h later . Teicoplanin was given intravenously at a dosage of 6 mg/kg of body weight at 0, 12, and 24 h and once a day thereafter . Five to eleven blood samples per patient were collected . Teicoplanin concentrations were measured by liquid chromatography . A bicompartmental model was fitted to the data by a nonlinear mixed-effect-model approach . Multiple-linear regression analysis was applied in an attempt to correlate PK parameters to nine covariates . The mean trough concentrations of teicoplanin 48 h after the onset of treatment and 24 h after the last injection (last trough) +/- standard deviations were 8.8 +/- 4.1 and 17.5 +/- 13.5 mg/liter, respectively . A significant increase was noted in the mean rate of elimination clearance of teicoplanin in neutropenic patients compared with that of HV (0.86 versus 0.73 liter/h, P = 0.002), as was the case with rates of distribution clearance (5.89 versus 4.94 liter/h, P = 0.002); the mean half-life of distribution was significantly shorter in patients than in HV (0.43 versus 0.61 h, P = 0.002) . In contrast, the volumes of the central compartment (ca . 5.8 liters for both groups), the volumes of distribution at steady state (HV, 37.6 liters; patients, 55.9 liters), and the elimination half-lives (HV, 39.6 h; patients, 52.7 h) were not significantly different between HV and neutropenic patients . Interindividual variabilities of rates of clearance (coefficient of variation {CV}, 43%) and elimination half-lives (CV, 56%) were mainly explained by the variabilities among rates of creatinine clearance . Interindividual variabilities of the volumes of the central compartment (CV, 33%) and the volumes of distribution at steady state (CV = 51%) were correlated to interindividual variabilities among numbers of leukocytes and the ages of patients, respectively . On the basis of the population PK model of teicoplanin, simulations were made to optimize the dosing schedule . A supplemental 6 mg/kg dose of teicoplanin at 36 h resulted in a trough concentration at 48 h of 16.0 +/- 4.5 mg/liter, with only 7% of patients having a trough concentration of less than 10 mg/liter, compared with 46% of patients on the usual schedule.

Thorax, 1996 May, 51(5), 539 - 40
Radiographic features of staphylococcal pneumonia in adults and children; Macfarlane J et al.; BACKGROUND: Clinical and laboratory features do not accurately correlate with the cause of community acquired pneumonia . A study was performed to examine whether the radiographic features of staphylococcal pneumonia are sufficiently distinct to aid early diagnosis . METHODS: The chest radiographs of 34 patients (including eight children) with proven staphylococcal pneumonia were reviewed by two experienced observers using methods described previously . Features on presentation and follow up were noted . RESULTS: The most striking features were the presence of multilobar consolidation on presentation, cavitation, pneumatocoeles and spontaneous pneumothorax, together with a tendency to radiographic deterioration after admission in both adults and children . Some of these features are much less common with other causes of community acquired pneumonia . However, most of the cases did not have these classic features . CONCLUSIONS: The presence of certain radiographic features, including multilobar shadowing, cavitation, pneumatocoeles, and spontaneous pneumothorax, are seen with staphylococcal pneumonia in adults and children, but their absence does not exclude the diagnosis.

Immunology, 1996 May, 88(1), 13 - 9
Repopulation of blood lymphocyte sub-populations in rheumatoid arthritis patients treated with the depleting humanized monoclonal antibody, CAMPATH-1H; Brett S et al.; Patients with severe rheumatoid arthritis who had failed treatment with conventional therapies were treated with a course of five or 10 daily intravenous infusions of CAMPATH-1H, a humanized antibody against the CD52 antigen, resulting in profound depletion of peripheral blood mononuclear cells . During the subsequent 18 months, lymphocytes were analysed for sub-populations by fluorescence-activated cell sorter (FACS) and for proliferation in response to polyclonal T-cell stimulation with anti-CD3 or staphylococcal enterotoxin B (SEB) . Treatment resulted in almost complete depletion of lymphocytes from the blood followed by gradual repopulation . CD16+ natural killer (NK) cells and CD14+ monocytes returned to pretreatment levels within 1-2 months . CD19+ B cells returned to within 50% of pre-treatment levels by day 66 and to within normal range by day 150, whereas CD8+ T cells recovered to 50% of pretreatment levels by day 66, but did not show any further increase during the rest of the study period . The most profound effects were on the CD4+ T lymphocyte sub-population, as the mean CD4+ count did not increase above 20% of pre-treatment level at any time during the study period (550 days), at all the doses tested . The T cells which initially repopulated the blood 1-2 months after treatment, nearly all expressed the activation markers human leucocyte antigen (HLA)-DR and CD45RO, although the percentage of T cells expressing these molecules gradually declined to normal levels over time . Proliferative responses to polyclonal T-cell stimulation (anti-CD3 and SEB) were also significantly reduced in the first few months after treatment, but recovered to pre-treatment levels by day 250 . The relationship between these observations and the clinical response is discussed.

Clin Diagn Lab Immunol, 1996 May, 3(3), 301 - 4
Utility of flow cytometric detection of CD69 expression as a rapid method for determining poly- and oligoclonal lymphocyte activation; Simms PE et al.; CD69 is a lymphoid activation antigen whose rapid expression (< or = 2 h postactivation) makes it amenable for the early detection of T-cell activation and for subset activation analyses . In the present study we evaluated the utility of flow cytometric detection of CD69 expression by T cells activated with polyclonal stimuli (anti-CD3 and staphylococcal enterotoxin B {SEB}) and oligoclonal stimuli (tetanus toxoid and allogeneic cells) using flow cytometry . Following activation of T cells with anti-CD3 or SEB, CD69 is detectable at < or = 4 h following activation, with anti-CD3 peaks at 18 to 48 h . Dose titration experiments indicated that CD69 expression largely paralleled that in {3H}thymidine incorporation assays, although the former offered a more sensitive measure of T-cell activation at limiting doses of activator than {3H}thymidine incorporation when cells were activated with either anti-CD3 or SEB . However, activation of T cells with either tetanus toxoid or allogeneic stimulator cells failed to induce detectable CD69 expression at up to 7 days of culture . Subset analyses of anti-CD3- and SEB-activated T cells indicated that populations other than T cells can express CD69 following stimulation with T-cell-specific stimuli, indicating that CD69 can be induced indirectly in non-T cells present in the population . These findings indicate that CD69 is a useful marker for quantifying T-cell and T-cell subset activation in mixed populations but that its utility might be restricted to potent stimuli that are characterized by their ability to activate large numbers of cells with rapid kinetics.

J Mol Evol, 1996 May, 42(5), 543 - 51
Cloning and sequencing analysis of three amylase cDNAs in the shrimp Penaeus vannamei (Crustacea decapoda): evolutionary aspects; Van Wormhoudt A et al.; In Penaeus vannamei, alpha-amylase is the most important glucosidase and is present as at least two major isoenzymes which have been purified . In order to obtain information on their structure, a hepatopancreas cDNA library constructed in phage lambda-Zap II (Strategene) was screened using a synthetic oligonucleotide based on the amino acid sequence of a V8 staphylococcal protease peptide of P . vannamei alpha-amylase . Three clones were selected: AMY SK 37 (EMBL sequence accession number: X 77318) is the most complete of the analyzed clones and was completely sequenced . It contains the complete cDNA sequence coding for one of the major isoenzymes of shrimp amylase . The deduced amino acid sequence shows the existence of a 511-residue-long pre-enzyme containing a highly hydrophobic signal peptide of 16 amino acids . Northern hybridization of total RNA with the amylase cDNA confirms the size of the messenger at around 1,600 bases . AMY SK 28, which contains the complete mature sequence of amylase, belonged to the same family characterized by a common 3' terminus and presented four amino acid changes . Some other variants of this family were also partially sequenced . AMY SK 20 was found to encode a minor variant of the protein with a different 3' terminus and 57 amino acid changes . Phylogenetic analysis established with the conserved amino acid regions of the (beta/alpha) eight-barrel domain and with the total sequence of P . vannamei showed close evolutionary relationships with mammals (59-63% identity) and with insect alpha-amylase (52-62% identity) . The use of conserved sequences increased the level of similarity but it did not alter the ordering of the groupings . Location of the secondary structure elements confirmed the high level of sequence similarity of shrimp alpha-amylase with pig alpha-amylase.

J Leukoc Biol, 1996 May, 59(5), 623 - 30
Interleukin-12 protects thermally injured mice from herpes simplex virus type 1 infection; Matsuo R et al.; Severe burn injury is associated with increased susceptibility to severe herpesvirus infections . Type 2 cytokines {interleukin (IL)-4 and IL-10} released from burn-associated CD8+ type 2 T cells (BA-type 2 T cells) have been shown to play a role in the increased susceptibility of thermally injured mice (TI-mice) to herpes simplex virus type 1 (HSV-1) infection . Because IL-12 has been shown to inhibit the generation of type 2 T cells, murine rIL-12 was injected into TI-mice exposed to HSV-1 to determine whether IL-12 could influence HSV-1 infections in individuals bearing type 2 T cells . rIL-12 improved the resistance of TI-mice or mice inoculated with T6S cells (a BA-type 2 T cell clone) against HSV-1 infection . Type 2 cytokines were detected in sera of TI-mice or mice inoculated with T6S cells (T6S-mice) . However, treatment of TI-mice or T6S-mice with rIL-12 inhibited type 2 cytokine production in the sera of these mice . All TI-mice exposed to a lethal dose of HSV-1 survived when they were treated with a mixture of monoclonal antibodies (mAbs) against type 2 cytokines . Staphylococcal enterotoxin A {an interferon-gamma (IFN-gamma) inducer} stimulated serum IFN-gamma production in TI-mice and T6S-mice treated with rIL-12, whereas no IFN-gamma was produced in mice treated with saline . These results suggest that IL-12 has the potential to protect TI-mice infected with a lethal dose of HSV-1 via a shift to type 1 T cell responses from type 2 T cell responses.

Eur J Immunol, 1996 May, 26(5), 1170 - 4
The role of oxygen in thymocyte apoptosis; McLaughlin KA et al.; Signals generated by T cell receptor (TCR) cross-linking (or phorbol 12-myristate-13-acetate + Ca2+ ionophore), glucocorticoids or ionizing radiation all stimulate apoptotic cell death in thymocytes by signals that are initially distinct from each other . However, when these stimuli were administered to thymocyte cultures that were maintained under an atmosphere containing less than 20 ppm oxygen as opposed to one that contained 18.5% molecular oxygen, cell death was inhibited or abrogated, suggesting that the induction of death by all three different stimuli depend on the presence of molecular oxygen . Studies of the effects of the cysteine analog N-acetyl cysteine (NAC) with normal thymocytes demonstrated that this antioxidant inhibited the induction of death by each of the different stimuli in a manner the paralleled anaerobiosis . Furthermore, studies with thymocytes demonstrated that the induction of nur77, a gene shown to be involved in thymocyte apoptosis signaled through the TCR or its surrogates, is not inhibited by NAC or dependent upon molecular oxygen . The possible implications for negative selection of NAC-mediated inhibition of TCR-signaled thymocyte cell death was examined in thymic organ culture . Treatment of these cultures with NAC provided significant protection against staphylococcal enterotoxin B-mediated deletion of V beta 8-expressing thymocytes.

Eur J Immunol, 1996 May, 26(5), 1074 - 82
Human CD4 and human major histocompatibility complex class II (DQ6) transgenic mice: supersensitivity to superantigen-induced septic shock; Yeung RS et al.; Rodents are significantly less sensitive to enterotoxin-induced shock, and are thus not valid human disease models . Here, we describe a mouse strain carrying the human CD4 and human major histocompatibility complex (MHC) class II (DQ6) transgenes in an endogenous CD4- and CD8-deficient background . T lymphocytes from these animals react to minute amounts (10-100 times less than control mice) of staphylococcal enterotoxin B (SEB) in vitro, similar to concentrations to which human cells react . In vivo, these double-transgenic, double-knockout mice succumb to normally sublethal amounts of SEB . This sensitivity is not due to a biased T cell receptor V beta repertoire, increased T cell reactivity, or increased sensitivity to macrophage-derived cytokines . Rather, tumor necrosis factor (TNF)-alpha production by T cells and serum levels of TNF-alpha correlate precisely with the clinical syndrome, showing a biphasic T cell-dependent response . These data show that both human CD4 and MHC class II molecules can render mice supersensitive to superantigen-induced septic shock syndrome . This animal model mimics the progression of septic shock in man by transforming normally resistant mice into hypersensitive SEB responders, a trait that is characteristic of humans . Mice that have been humanized by exchanging autochthonous superantigen ligands by their human equivalents may be useful to decipher superantigen responses in vivo and to assess the pathogenesis of superantigen-associated diseases.

Br J Haematol, 1996 May, 93(2), 427 - 31
Fusidic acid induced acute immunologic thrombocytopenia; El-Kassar N et al.; Fusidic acid is used in hospitals as second-line therapy for multidrug-resistant staphylococcal infections . We report the first fully documented case of fusidic acid induced thrombocytopenia, in a 48-year-old patient . The thrombocytopenia was abrupt and severe but resolved spontaneously 7 d after drug withdrawal . The thrombocytopenia transiently relapsed 6 d later, when fusidic acid was reintroduced . Haemorrhagic signs were observed, but no severe bleeding occurred . Platelet transfusions failed to increase the platelet count . We detected an IgG platelet antibody in the patient's serum, that specifically recognized platelet glycoprotein IIb/IIIa only in the presence of fusidic acid . Fusidic acid induced thrombocytopenia should be considered as a possible cause for the thrombocytopenia frequently seen in the intensive care setting.

Scand J Immunol, 1996 May, 43(5), 545 - 50
In vivo activation of T-cell induction into the primed phenotype and programmed cell death by staphylococcal enterotoxin B; Aroeira LS et al.; The authors demonstrate that SEB immunization activates V beta 8+ T cells and induces the acquisition of the primed phenotype as defined previously by low MEL-14 and high Pgp-1 expression . SEB-activated spleen CD4+ and CD8V beta 8+ T cells have different population dynamics and regulate the expression of MEL-14 and Pgp-1 differentially, suggesting that the SEB-MHC class II complex preferentially activates CD4V beta 8+ T cells . Interestingly, at day 3 after SEB immunization, V beta 8+ T cells expressing low, but not high, levels of MEL-14 undergo apoptosis, indicating that T-cell activation is a prerequisite for triggering programmed cell death . These results might help to trace antigen-reactive cells to the activated or primed pool, as well as to identify those cells which will undergo programmed cell death.

J Infect Dis, 1996 May, 173(5), 1263 - 7
Staphylococcal food poisoning caused by imported canned mushrooms; Levine WC et al.; From February through April 1989, four outbreaks of staphylococcal food poisoning in the United States were associated with eating mushrooms canned in the People's Republic of China (PRC) . In the four outbreaks, 99 persons who ate at a suspect facility developed gastrointestinal symptoms within 24 h, including 18 who were hospitalized . Illness was associated with eating mushrooms at a university cafeteria (relative risk {RR} = 53.0), a hospital cafeteria (RR = 13.8), a pizzeria (odds ratio {OR} = infinity), and a restaurant (OR = infinity) (all P < .0001) . Staphylococcal enterotoxin A was found by ELISA in mushrooms at the sites of two outbreaks and in unopened cans from the three plants thought to have produced mushrooms implicated in outbreaks . These investigations led to multistate recalls and a US Food and Drug Administration order to restrict entry into the United States of all mushrooms produced in the PRC; until this action, the United States imported approximately 50 million pounds yearly.

Clin Exp Immunol, 1996 May, 104(2), 366 - 73
Human natural killer (NK) cells present staphylococcal enterotoxin B (SEB) to T lymphocytes; D'Orazio JA et al.; Superantigen-mediated T cell activation requires the participation of antigen-presenting cells (APC) . Once superantigen has bound class II MHC molecules on the surface of APC, it then can interact with the T cell receptor to induce T cell activation . Superantigen-mediated T lymphocyte activation, along with its consequent cytokine production is thought to be the basis for the pathophysiology of conditions such as toxic shock syndrome, Kawasaki's disease and possibly rheumatoid arthritis . We examined the role of CD56+ NK lymphocytes in the interaction between superantigens and T lymphocytes . First, we found that a subpopulation of CD56+ cells freshly isolated from human peripheral blood expressed class II MHC molecules . The amount of HLA-DR expression varied between individuals, ranging from 9.3% to 37.7% . CD56+ (NK) cells were purified from the peripheral blood by cell sorting and were tested for their ability to support SEB-mediated T cell activation as assessed by surface expression of IL-2 receptor alpha-chain (CD25) on CD3+ lymphocytes . We observed that when enriched T cells were incubated with SEB in the presence of NK cells, there was a significant up-regulation of CD25 expression of the T cells . When HLA-DR+ cells were removed from sorted CD56+ populations, the remaining HLA-DR- NK cells were unable to support SEB-mediated T cell activation . Also, SEB up-regulated the expression of HLA-DR on CD56+ cells in peripheral blood mononuclear cell (PBMC) populations after 24 h of incubation, implying that the ability of NK cells to function as superantigen-presenting cells is up-regulated by superantigens themselves . Together, these data demonstrate for the first time that human CD56+ HLA-DR+ NK cells can function as superantigen-presenting cells, and imply that NK cells may be involved in the activation of non-specific T cell reactivity during early host defences against superantigen-elaborating microorganisms in vivo . Furthermore, the physical linkage of NK cells and T cells by the interaction of superantigen with HLA class II molecules and T cell receptors, respectively, may lead to NK cell activation and augmented lytic potential, helping to clear the body of superantigen-elaborating microorganisms.

Am Fam Physician, 1996 May 1, 53(6), 2045 - 9
Endocarditis in injection drug users; DeWitt DE et al.; Injection drug use is an important risk factor for endocarditis . The clinical manifestations of endocarditis associated with injection drug use differ from those in person who do not use drugs . Endocarditis in drug users more often affects the right side of the heart and presents with fever and pulmonary emboli rather than left-sided emboli . Blood cultures and echocardiography are the mainstay of diagnosis; these tests are particularly helpful in identification of endocarditis associated with injection drug use because of the high frequency of right-sided valvular involvement and the low incidence of culture-negative endocarditis in this population . Since staphylococcal species are the dominant causative organism, penicillin and an aminoglycoside are the treatments of choice . Injection drug users with left-sided endocarditis or with symptomatic human immunodeficiency virus infection have poor prognoses.

Virology, 1996 May 1, 219(1), 307 - 13
Proteolytic activity of human immunodeficiency virus Vpr- and Vpx-protease fusion proteins; Wu X et al.; In addition to Gag, Pol, and Env, primate lentiviruses encode other virion-associated proteins, including Vpr, Vpx, and Vif . Vpr- and Vpx-staphylococcal nuclease and chloramphenicol acetyltransferase fusion proteins incorporate into human immunodeficiency virus (HIV) virions and retain enzyme activity when expressed in trans with HIV proviruses (Wu et al., J . Virol . 69, 3389, 1995) . To explore whether the viral protease (PR) could be expressed as a proteolytically active fusion protein, the HIV PR coding region was fused in-frame with the HIV-2 vpx and HIV-1 vpr genes . Using a vaccinia virus-T7 expression system, the Vpx-PR fusion protein was expressed and formed homodimers . Coexpression with Pr55Gag demonstrated that Vpx-PR possessed Gag-specific proteolytic activity and inhibited the production of Gag virus-like particles . Trans-expression of a PR-Vpr fusion protein with HIV-1 provirus caused a profound reduction in viral protein expression and virion production . Importantly, the PR-Vpr fusion protein caused a similar level of inhibition and intracellular cleavage of Pr55Gag precursor protein when coexpressed with protease defective HIV-1 provirus . The inhibitory effect of PR-Vpr expression on virion production was markedly greater than that of PR alone . These results indicate that Vpr arguments the intracellular proteolytic activity of PR when expressed as a fusion protein and thus may be relevant for the expression of PR in intracellular immunization strategies against HIV infection . Moreover, the ability to express and package enzymatically active PR-Vpr fusion protein, independent of Gag/Pol, may provide a novel means to study enzyme function.

J Am Acad Dermatol, 1996 May, 34(5 Pt 2), 911 - 4
Infectious complications of erythrodermic psoriasis; Green MS et al.; Severe morbidity and mortality may be associated with erythrodermic psoriasis, especially when complicated by septicemia . We describe five patients with erythrodermic psoriasis complicated by staphylococcal septicemia . In two, concurrent infection with HIV increased vulnerability to bacteremia.

Clin Immunol Immunopathol, 1996 May, 79(2), 122 - 33
In vitro inhibition by intravenous immunoglobulin of human T cell-dependent B cell differentiation induced by staphylococcal superantigens; Stohl W et al.; Treatment with intravenous Ig (IVIG) is efficacious not only in humoral immunodeficiency diseases but in several nonimmunodeficiency disorders as well . Since microbial superantigens (SAg) have been postulated to play a role in promoting in vivo pathogenic autoantibody production and since IVIG preparations are rich in anti-SAg antibodies, we tested whether IVIG could inhibit in vitro SAg-driven human T cell-dependent B cell differentiation . We demonstrate that IVIG inhibits such B cell differentiation by at least three different mechanisms . Early addition of IVIG inhibits B cell differentiation not only in SAg-stimulated PBMC cultures but in anti-CD3- and pokeweed mitogen (PWM)-stimulated cultures as well, pointing to a SAg-nonspecific inhibitory effect . However, anti-SAg antibodies contained in IVIG can also effect SAg-specific inhibition, since polyclonal rabbit anti-SAg antisera added early to peripheral blood mononuclear cell (PBMC) cultures inhibit neither anti-CD3- nor PWM-driven B cell differentiation and inhibit B cell differentiation triggered only by the specific SAg against which the individual antiserum was raised . Finally, late addition of IVIG at a time at which B cells have already committed to terminal differentiation inhibits SAg-driven, but not anti-CD3- or PWM-driven, generation of Ig-secreting cells (IgSC) . This late inhibition is associated with enhanced SAg-dependent cytolytic activity against Raji cell targets which is dramatic in PBMC cultures but is often not detectable in T + B cell cultures . Reconstitution of T + B cell cultures with natural killer cells restores the enhancing capacity of IVIG on SAg-dependent cytolytic activity as well as the late inhibitory effects of IVIG on IgSC generation . Understanding the multiple mechanisms through which IVIG can inhibit SAg-driven B cell differentiation may offer a rational basis for determining which patients are likely to favorably respond to IVIG administration.

Infect Immun, 1996 May, 64(5), 1706 - 13
Intranasal and intramuscular proteosome-staphylococcal enterotoxin B (SEB) toxoid vaccines: immunogenicity and efficacy against lethal SEB intoxication in mice; Lowell GH et al.; Intranasal or intramuscular (i.m.) immunization of mice and i.m . immunization of rabbits with formalinized staphylococcal enterotoxin B (SEB) toxoid in saline elicited higher anti-SEB serum immunoglobulin G (IgG) titers when the toxoid was formulated with proteosomes . In addition, intranasal immunization of mice with this proteosome-toxoid vaccine elicited high levels of anti-SEB IgA in lung and intestinal secretions, whereas the toxoid without proteosomes did not . Two i.m . immunizations with proteosome-toxoid plus alum also induced higher murine serum responses than alum-adjuvanted toxoid without proteosomes . Furthermore, proteosome-toxoid delivered intranasally in saline or i.m . with either saline or alum afforded significant protection against lethal SEB challenge in two D-galactosamine-sensitized murine models of SEB intoxication, i.e., the previously described i.m . challenge model and a new respiratory challenge model of mucosal SEB exposure . Efficacy correlated with the induction of high serum levels of anti-SEB IgG . In contrast, intranasal or i.m . immunization with toxoid in saline without proteosomes was not significantly protective in either challenge model . Proteosome-toxoid plus alum given i.m . also elicited more significant protection against respiratory challenge than the alum-adjuvanted toxoid alone . The capacity of proteosomes to enhance both i.m . and intranasal immunogenicity and efficacy of SEB toxoid indicates that testing such proteosome-SEB toxoid vaccines in the nonhuman primate aerosol challenge model of SEB intoxication prior to immunogenicity trials in humans is warranted . These data expand the applicability of the proteosome mucosal vaccine delivery system to protein toxoids and suggest that respiratory delivery of proteosome vaccines may be practical for enhancement of both mucosal and systemic immunity against toxic or infectious diseases.

J Mol Biol, 1996 Apr 19, 257(5), 1112 - 26
Stability changes upon mutation of solvent-accessible residues in proteins evaluated by database-derived potentials; Gilis D et al.; The stability changes in peptides and proteins caused by the substitution of a single amino acid, which can be measured experimentally by the change in folding free energy, are evaluated here using effective potentials derived from known protein structures . The analysis is focused on mutations of residues that are accessible to the solvent . These represent in total 106 mutations, introduced at different sites in barnase, bacteriophage T4 lysozyme and chymotrypsin inhibitor 2, and in a synthetic helical peptide . Assuming that the mutations do not modify the backbone structure, the changes in folding free energies are computed using various types of database-derived potentials and are compared with the measured ones . Distance-dependent residue-residue potentials are found to be inadequate for estimating the stability changes caused by these mutations, as they are dominated by hydrophobic interactions, which do not play an essential role at the protein surface . On the contrary, the potentials based on backbone torsion angle propensities yield quite good results . Indeed, for a subset of 96 out of the 106 mutations, the computed and measured changes in folding free energy correlate with a linear correlation coefficient of 0.87 . Moreover, the ten mutations that are excluded from the correlation either seem to cause modifications of the backbone structure or to involve strong hydrophobic interactions, which are atypical for solvent-accessible residues . We find furthermore that raising the ionic strength of the solvent used for measuring the changes in folding free energies improves the correlation, as it tends to mask the electrostatic interactions . When adding to these 106 mutations 44 mutations performed in staphylococcal nuclease and chemotactic protein, which were first discarded because some of them were suspected to affect the backbone conformation or the denatured state, the correlation between measured and computed folding free energy changes remains quite good: the correlation coefficient is 0.86 for 135 out of the 150 mutations . The success of the backbone torsion potentials in predicting stability changes indicates that the approximations made for deriving these potentials are adequate . It suggests moreover that the local interactions along the chain dominate at the protein surface.

J Mol Biol, 1996 Apr 5, 257(3), 497 - 9
The M32L substitution of staphylococcal nuclease: disagreement between theoretical prediction and experimental protein stability; Spencer DS et al.; The M32L substitution mutation of staphylococcal nuclease was made to test the theoretical prediction by Yamaotsu, Moriguchi and Hirono that it would be approximately 1.6 kcal/mol more stable than the wild-type protein . Instead M32L and the closely related M32I mutant were 0.8 and 0.6 kcal/mol less stable than the wild-type protein, respectively . The theoretical treatment had successfully predicted the stability effects of other mutations in staphylococcal nuclease . The discrepancy found here may be due to a general problem of the theoretical treatment, such as inadequate molecular dynamics simulation time, or possibly due to more specific difficulty in assessing the strength of the sulfur-aromatic interaction that is present in the wild-type.

Proc Natl Acad Sci U S A, 1996 Apr 2, 93(7), 3037 - 42
Major histocompatibility complex class I molecule serves as a ligand for presentation of the superantigen staphylococcal enterotoxin B to T cells; Haffner AC et al.; Superantigens, such as staphylococcal enterotoxin B (SEB), elicit a strong proliferative response in T cells when presented in the context of major histocompatibility complex (MHC) class II molecules . We observed a similar T-cell response, when MHC class II-negative epidermal cell lines were employed as antigen-presenting cells . Immunoprecipitation studies indicated that the ligand to which SEB bound had a molecular mass of 46 kDa . Radiolabeled SEB could be immunoprecipitated from isolated membrane proteins on the SCC13 epidermal cell line with a monoclonal antibody directed against the MHC class I molecule, and transfection of the K-562 cell line with MHC class I molecules showed a 75% increased SEB-binding capacity compared with the nontransfected MHC class I- and class II-negative counterpart . In functional studies, antibodies to the MHC class I molecule inhibited T-cell proliferation by at least 50% . From these studies, we conclude that MHC class I molecules on malignant squamous cell carcinomas serve as ligands for SEB, which, given the appropriate costimulatory signals, is sufficient to allow for superantigen-induced T-cell proliferation.

FEMS Microbiol Lett, 1996 Apr 1, 137(2-3), 279 - 84
Inducible production and cellular location of the epidermin biosynthetic enzyme EpiB using an improved staphylococcal expression system; Peschel A et al.; The antimicrobial peptide epidermin is distinguished by thioether amino acids such as meso-lanthionine, 3-methyl-lanthionine, and 2-aminovinylcysteine . The enzyme EpiB, encoded on a plasmid of the producing strain Staphylococcus epidermidis Tu3298, is very likely involved in the formation of these unusual amino acids . In order to obtain high-level production of EpiB, an improved staphylococcal expression vector based on the xylose-inducible xylA promoter of Staphylococcus xylosus was constructed . As shown by the expression of a lipase reporter gene, the new plasmid pTX15 mediated a considerably higher expression level after induction and a lower background expression level in the uninduced state than the previously described vector pCX15 . The epiB gene was inserted in pTX15 and expressed in Staphylococcus carnosus . The EpiB protein was detected both in the cytoplasmic and the membrane fraction and was partially purified in three steps.

J Clin Microbiol, 1996 Apr, 34(4), 993 - 4
Vertebral osteomyelitis due to Staphylococcus lugdunensis; Murdoch DR et al.; We present the first reported case of vertebral osteomyelitis due to Staphylococcus lugdunensis . The infection occurred in an 80-year-old woman who had been taking glucocorticosteroids . S . lugdunensis is a coagulase-negative staphylococcus with considerable potential as a human pathogen . Isolation of this organism should be regarded as significant unless evidence suggests otherwise.

Int J Food Microbiol, 1996 Apr, 29(2-3), 281 - 95
A collaborative study on the detection of staphylococcal enterotoxins in foods by an enzyme immunoassay kit (RIDASCREEN); Park CE et al.; The RIDASCREEN SET kit (R-Biopharm GmbH, Darmstadt, Germany), a commercial staphylococcal enterotoxin (SE) immunoassay kit, utilizes monovalent capture antibodies against SE types A to E (SEA to SEE); therefore, it simultaneously detects and identifies the enterotoxin types . A collaborative study was conducted to ascertain whether the specificity, sensitivity, repeatability and reproducibility of the kits would meet food safety criteria . Twelve Canadian laboratories participated in this study to analyze various foods to which 1.0 to 2.0 ng of SE/g had been added and negative control samples . The results indicate that the sensitivity and specificity of the kit were excellent; all collaborators were able to detect the minimum toxin levels of 1.0 ng SEA/g in ham and cheese, 1.0 ng SEB/g in salami and turkey, and 2.0 ng SED/g in other samples without any false-negative results . With regard to negative control samples, all analysts obtained correct results except for one analyst who recorded weak false-positive results with several foods detecting SEC or SEA . The overall rate of false-positive results was 0.7% for 600 triplicate assays . In addition, it was confirmed that the RIDASCREEN kit did not yield false-positive results with mussels in contrast to some other EIA kits . Overall repeatability and reproducibility of the kit were in the range of 11.69-42.57% and 17.25-68.05%, respectively.

J Autoimmun, 1996 Apr, 9(2), 193 - 204
Analysis of function, specificity and T cell receptor expression of cloned mucosal T cell lines in Crohn's disease; Prindiville TP et al.; Monoclonal populations of mucosal T cells were established from the earliest visible lesions in eight patients with well defined Crohn's disease . The FACS phenotype of all the mucosal derived clones to date are TCR alpha/beta+, CD3+, CD4+, and CD45RO+ memory cells . TCR variable region Beta chain analysis revealed predominantly V beta families 1, 2, 5.1, 5.2, 6, 7 and 8, with V beta family analysis supporting antigen expansion in the diseased mucosa . Putative autoreactivity was evaluated by stimulating individual clones with a battery of antigens and determining proliferation and IL-2 production by thymidine incorporation at 72 h . Antigens tested included crude Crohn's diseased (CD) colon and small bowel homogenates, CD brush border preparations, crude CD colon and small bowel mucin, and purified CD small bowel mucin . Controls included clone, APC, tetanus toxoid and either PHA or Staphylococcus enterotoxin B . A total of 200 clones were studied with 29.5% or 59 clones demonstrating proliferation and/or IL-2 production . T cell receptor V beta gene usage evaluated in a small number of reactive clones correlated with the expanded patient families . Seven of the fifteen represented families revealed diverse T cell receptor gene use and no disease overlap.

J Vet Pharmacol Ther, 1996 Apr, 19(2), 118 - 23
In vitro activity of fifteen antimicrobial agents against methicillin-resistant and methicillin-susceptible Staphylococcus intermedius; Piriz S et al.; In this study the susceptibility of 91 methicillin-resistant and -susceptible Staphylococcus intermedius strains (MRSI and MSSI, respectively) against 15 antimicrobial agents was determined . The activity of the antimicrobial agents was studied at pH 7.2 and pH 8.5 . Methicillin was more active at pH 7.2 (28 strains methicillin-resistant) than at pH 8.5 (55 strains methicillin-resistant) . Gentamicin showed excellent activity, with only 3 strains resistant at pH 8.5 . However, gentamicin would have to be administered parenterally . Oxytetracycline cannot be recommended for treatment of canine staphylococcal dermatitis, due to the high percentage (over 25%) of strains that were found to be resistant . Clindamycin showed little activity in inhibiting growth of the strains studied, the percent resistance at pH 7.2 was 93.4% . Rifampin behaved differently at the two pH values . However, a close relationship was noted between methicillin-resistant and rifampin-resistant strains, particularly at the lower pH . Of the fluoroquinolones, ciprofloxacin or enrofloxacin would be a good useful alternative for the treatment of methicillin-resistant strains of S . intermedius . Lastly, very high resistance to sulphamethoxypyridazine was found, as was the case with trimethoprim and a combination of trimethoprim/sulphamethoxypyridazine, against not only MRSI but also MSSI strains.

Res Commun Mol Pathol Pharmacol, 1996 Apr, 92(1), 85 - 93
A distinctive effect of CCCP on the transfer of erythromycin to 1-octanol: a possible model in promoting the intracellular antibiotic-accumulation through lipid in a staphylococcal cytoplasmic membrane; Matsuoka M et al.; Movement of erythromycin (EM), a basic antibiotic solute (pKa 8.6), in an aqueous buffer (pH7.6) at 37 degrees C into 1-octanol was found approximately twofold greater in the presence of another acidic and lipophilic solute, carbonylcyanide m-chlorophenylhydrazone (CCCP), when compared with the EM-movement in the absence of CCCP . CCCP appears to behave just like a carrier of EM, besides being a well-known inhibitor, such as the uncoupling agent of oxidative phosphorylation . The probability is discussed that such an analogous event takes place in the lipid layers of a bacterial-cell membrane.

J Chemother, 1996 Apr, 8(2), 102 - 6
Effect of beta-lactamase inhibitors on normal immune capabilities and their interactions with staphylococcal pathogenicity; Tawfik AF et al.; The effects of the beta-lactamase inhibitors, clavulanic acid, sulbactam and tazobactam on normal immune responses were investigated . These agents did not interfere with either humoral or cell-mediated immune responses as measured by the hemolytic plaque assay and delayed type hypersensitivity reaction assay respectively . In addition, human polymorphonuclear leukocyte phagocytic activity was not altered by these agents . When these agents were tested for their effect on Staphylococcus aureas adherence to buccal epithelial cells we found that all inhibitors suppressed staphylococcal adherence at therapeutic serum concentrations . Among the inhibitors investigated, sulbactam was found to significantly inhibit the hemolysin production of S . aureus . These data suggest that beta-lactamase inhibitors do not exhibit immunomodulating activity, but they interfere with some of the virulence factors of S . aureus . These findings suggest the advantage of preparations containing these inhibitors.

Mol Immunol, 1996 Apr, 33(6), 521 - 30
The stoichiometry and affinity of the interaction of murine Fc fragments with the MHC class I-related receptor, FcRn; Popov S et al.; The binding of recombinant wild type and mutant Fc-hinge fragments to soluble, FcRn expressed in insect cells has been analysed . The mutant Fc-hinge fragments are derived from murine IgG1 with mutation of residues located at the CH2-CH3 domain interface (Ile253, His31O, Gln311, His433 and Asn434; EU numbering) . These mutant Fc-hinge fragments have previously been shown to be deficient in neonatal transcytosis in suckling mice and also have abnormally short serum half lives . The mutated residues are highly conserved in human and rodent gammaglobulins (IgGs) and are also involved in binding to staphylococcal protein A . This study demonstrates that the Fc mutants have lower binding affinities for recombinant FcRn and mutations in the CH2 domain have a greater effect than those in the CH3 domain . There is an excellent correlation between affinity and transcytosis or the control of catabolism, and this provides further evidence in support of the close overlap of the sites of IgG/Fc involved in these processes . The stoichiometry of the FcRn:Fc interaction has also been investigated and has been found to be 1:1, indicating that binding of FcRn to one CH2-CH3 domain interface site precludes an FcRn:Fc interaction at the second site.

Immunology, 1996 Apr, 87(4), 586 - 92
Effects of antigen presentation on superantigen-induced apoptosis mediated by Fas/Fas ligand interactions in human T cells; Boshell M et al.; Stimulation of T cells with bacterial superantigens has several distinct functional outcomes including proliferation, anergy and apoptosis . At present however, the mechanisms that dictate whether activation, anergy, or apoptosis predominate are unclear . In this study we have investigated the effects of superantigen presentation to mature superantigen-reactive human T-cell lines . Despite expressing major histocompatibility complex (MHC) class II molecules, these lines failed to proliferate in response to superantigen in the absence of antigen-presenting cells (APC) but proliferated when minimal APC were added . In the absence of APC a significant proportion of the T cells underwent apoptosis . This response was rapid, antigen dependent and largely abolished by the addition of cyclosporin A . Interestingly the response was not blocked by the addition of a number of antibodies to cell surface molecules including MHC class II and intracellular adhesion molecule-1 . Using both a bioassay and messenger RNA analysis we were able to demonstrate that stimulation of these T cells with superantigen resulted in the induction of Fas-ligand expression on the T cells and furthermore, the ability of these cells to induce apoptosis was inhibited by the addition of blocking Fas antibodies as well as a Fas-Fc fusion protein . These data demonstrate that stimulation of T cells with staphylococcal enterotoxin B induces expression of Fas-ligand resulting in T-cell apoptosis; however, the final outcome of proliferation or apoptosis is determined by the presence of APC.

Immunology, 1996 Apr, 87(4), 566 - 72
Involvement of LFA-1/ICAM-2 adhesive interactions and PKC in activation-induced cell death following SEB rechallenge; Tchilian EZ et al.; Ligation of T-cell receptor (TCR) causes mature T cells to proliferate or, on re-exposure to antigen, can cause them to die by activation-induced cell death (AICD) . In proliferative responses, costimulatory and adhesive interactions are required and activation of protein kinase C (PKC) has been shown to be essential . Whether or not interactions involving costimulatory signals and PKC have a role in facilitating AICD remains unclear . Here we have examined the role of CD28/B7 and leucocyte function associated antigen-1 (LFA-1)/intracellular adhesion molecule (ICAM) mediated interactions in AICD triggered by staphylococcal enterotoxin B (SEB) in murine lymph node T cells . We show that, after a primary proliferative response to SEB, LFA-1/ICAM-2 adhesive interactions can play a part in AICD following SEB rechallenge, while B7 and ICAM-1 mediated interactions are not essential for this process . In addition, using a highly selective PKC inhibitor, Ro31.8425, we show that PKC activation is essential for the regulation of AICD by SEB rechallenge.

Int Immunol, 1996 Apr, 8(4), 519 - 23
Superantigen responses and co-stimulation: CD28 and CTLA-4 have opposing effects on T cell expansion in vitro and in vivo; Krummel MF et al.; Co-stimulation via the CD28/CTLA-4 system appears critical for T cell proliferation to peptide antigens presented in association with MHC . In this study, we examine the roles of CD28 and CTLA-4 in the response of murine T cells to the superantigen staphylococcal enterotoxin B (SEB) . In vitro, antibodies against B7-1/B7-2 or Fab fragments of anti-CD28 antibodies significantly inhibit the response of splenocytes to SEB . Conversely, Fab fragments of anti-CTLA-4 antibodies augment the proliferative response . Further, addition of blocking antibodies directed against B7-1/B7-2 augment proliferation co-stimulated by intact anti-CD28 antibodies . These data support the hypothesis that CD28 and CTLA-4 exert opposing effects upon early T cell activation . In vivo, intact anti-CD28 antibodies and non-stimulatory Fab fragments of anti-CD28 appear to have similar inhibitory effects upon the expansion of V beta 8+ T cells . In contrast, both intact and Fab fragments of anti-CTLA-4 appear to amplify this expansion . We conclude that the SEB response is significantly augmented by CD28-derived signaling and this in turn may be attenuated by signals through CTLA-4.

Scand J Immunol, 1996 Apr, 43(4), 391 - 7
Differential antigenic stimulation influences cytokine production patterns in T cells and CD4+ subpopulations; Ebtekar M et al.; The regulatory mechanisms that govern the commitment of T cells to a Th1 or Th2 lineage in terms of cytokine production patterns have not yet been fully elucidated . The authors have endeavored to study the role of the antigen in regulating the production of cytokines . To study this matter, a panel of antigens was chosen to include two random poly amino acids, PA1 (Poly(1-Phe, L-Glu)Poly-dL-Ala-PolyL-Lys), PA2 (Poly(Glu-NaAla), and two purified protein derivatives PPD1 (H37Rv virulent) and PPD2 (H37Ra non-virulent) obtained from WHO strains of Mycobacterium tuberculosis . After in vivo priming, murine spleen cells were prepared and three groups of cells (unfractionated, T cells, and CD4+ populations) were each separately stimulated in vitro with the original antigen Staphylococcal enterotoxin B (SEB) and phorbol myristate acetate (PMA) . ELISA assays were subsequently performed on supernatants for IL-4, IL-5, IL-2 and IFN-g . The results indicate a different cytokine pattern for the various antigenic stimulations . The PPD1 induced IL-5 production, while the PPD2 induced high levels of IFN-gamma . SEB was shown to exert a strong effect on the cytokine profile shifting it towards a Th1-like profile . A comparison is made between the cytokine patterns in different cells . The role of antigens and superantigens in regulating cytokine production and determining the outcome of the pathological process in relation to other regulatory factors is discussed.

J Exp Med, 1996 Apr 1, 183(4), 1437 - 46
Different superantigens interact with distinct sites in the Vbeta domain of a single T cell receptor; Hong SC et al.; CD4 T cell receptors (TCRs) recognize antigenic peptides presented by self major histocompatibility complex (MHC) class II molecules as well as non-self MHC class II molecules . The TCRs can also recognize endogenous retroviral gene products and bacterial toxins known collectively as superantigens (SAGs) that act mainly on the Vbeta gene segment-encoded portion of the Vbeta domain; most SAGs also require MHC II class for presentation . We have studied the interaction of the TCR from a well-characterized CD4 T cell line with SAGs by mutational analysis of its Vbeta domain . This appears to separate viral (v)SAG from bacterial (b)SAG recognition . T cells having a TCR with glycine to valine mutation in amino acid residue 51 (G51V) in complementarity determining region 2 of the TCR Vbeta domain fail to respond the bSAGs staphylococcal enterotoxin B (SEB), SEC1, SEC2, and SEC3, whereas they retain the ability to respond to non-self MHC class II molecules and to foreign peptides presented by self MHC class II molecules . It is interesting to note that T cells expressing mutations of both G51V and G53D of V beta regain the response to SEB and partially that to SEC1, but do not respond to SEC2, and SEC3, suggesting that different bacterial SAGs are viewed differently by the same TCR . These results are surprising, because it has been generally believed that SAG recognition by T cells is mediated exclusively by hypervariable region 4 on the exposed, lateral face of the TCR Vbeta domain . Response to the vSAG Mtv-7 was generated by mutation in Vbeta residue 24 (N24H), confirming previously published data . These data show that the vSAG Mtv-7 and bSAGs are recognized by different regions of the TCR Vbeta domain . In addition, various bSAGs are recognized differently by the same TCR . Thus, these mutational data, combined with the crystal structure of the TCR beta chain, provide evidence for distinct recognition sites for vSAG and bSAG.

Clin Pediatr (Phila), 1996 Apr, 35(4), 205 - 8
Addition of rifampin to cephalexin therapy for recalcitrant staphylococcal skin infections--an observation; Feder HM Jr et al.; We report two pediatric patients with recalcitrant staphylococcal infections whose infections resolved when rifampin was added to standard antistaphylococcal therapy . One patient had a post-varicella staphylococcal ulcerative lesion and did not respond to cephalexin alone but did respond when rifampin was added . A second patient had staphylococcal bullous impetigo and did not respond to dicloxacillin or cephalexin but did respond when rifampin was added to the cephalexin . If a patient fails to respond to traditional antistaphylococcal therapy, the addition of rifampin may be beneficial.

J Virol, 1996 Apr, 70(4), 2277 - 85
Protease-induced infectivity of hepatitis B virus for a human hepatoblastoma cell line; Lu X et al.; The human hepatoblastoma cell line HepG2 produces and secretes hepatitis B virus (HBV) after transfection of cloned HBV DNA . Intact virions do not infect these cells, although they attach to the surface of the HepG2 cell through binding sites in the pre-S1 domain . Entry of enveloped virions into the cell often requires proteolytic cleavage of a viral surface protein that is involved in fusion between the cell membrane and the viral envelope . Recently, we observed pre-S-independent, nonspecific binding between hepatitis B surface (HBs) particles and HepG2 cells after treatment of HBs antigen particles with V8 protease, which cleaves next to a putative fusion sequence . Chymotrypsin removed this fusion sequence and did not induce binding . In this study, we postulate that lack of a suitable fusion-activating protease was the reason why the HepG2 cells were not susceptible to HBV . To test this hypothesis, virions were partially purified from the plasma of HBV carriers and treated with either staphylococcal V8 or porcine chymotrypsin protease . Protease-digested virus lost reactivity with pre-S2-specific antibody but remained morphologically intact as determined by electron microscopy . After separation from the proteases, virions were incubated with HepG2 cells at pH 5.5 . Cultures inoculated with either intact or chymotrypsin-digested virus did not contain detectable levels of intracellular HBV DNA at any time following infection . However, in cultures inoculated with V8-digested virions, HBV-specific products, including covalently closed circular DNA, viral RNA, and viral pre-S2 antigen, could be detected in a time-dependent manner following infection . Immunofluorescence analysis revealed that 10 to 30% of the infected HepG2 cells produced HBV antigen . Persistent secretion of virus by the infected HepG2 cells lasted at least 14 days and was maintained during several reseeding steps . The results show that V8-digested HBV can productively infect tissue cultures of HepG2 cells . It is suggested that proteolysis-dependent exposure of a fusion domain within the envelope protein of HBV is necessary during natural infection.

Arch Biochem Biophys, 1996 Apr 1, 328(1), 122 - 8
Reversible thermal denaturation of staphylococcal nuclease: a Fourier transformed infrared spectrum study; Xie L et al.; The secondary structures of staphylococcal nuclease (SNase) have been assigned and semiquantitatively estimated from the deconvoluted Fourier transformed infrared (FTIR) spectrum . The changes in the secondary structures accompanying unfolding and refolding of SNase during reversible thermal denaturation up to 70 degrees C are followed by FTIR measurements . Only slight perturbation was observed up to 35 degrees C . The unfolding transition temperatures of beta-structure and alpha-helix are almost the same at 48.0-48.5 degrees C . During refolding the formation of the beta-structure follows the same pathway but that of the alpha-helix does not, although it recovers its original content almost completely . The final thermally denatured state at high temperature (60-70 degrees C) contains nonrandom structures in the complicated interaction, energetically resembling many kinds of structures . The occurrence of local conformational change before the final cooperative transition to the unfolded state during thermal denaturation as judged by FTIR spectra indicates that the unfolding and refolding of SNase may not follow the typical two-state model.

Eur J Immunol, 1996 Apr, 26(4), 858 - 62
Evidence that induction of tolerance in vivo involves active signaling via a B7 ligand-dependent mechanism: CTLA4-Ig protects V beta 8+ T cells from tolerance induction by the superantigen staphylococcal enterotoxin B; Lane P et al.; Co-stimulation through CD28 is thought to be necessary for the activation of unprimed CD4+ T cells, which are otherwise rendered tolerant . However, we previously found that CD4+ T cell priming was normal or augmented in mice which overexpressed a soluble form of CTLA4 where co-stimulation through CD28 was abrogated . To investigate this CD4+ T cell response, we exploited the capacity of the superantigen staphylococcal enterotoxin B to stimulate T lymphocytes bearing V beta 8+, which represent approximately 30% of all CD4+ T cells . In litter-mate controls of CTLA4-Ig transgenic mice, immunization with staphylococcal enterotoxin B leads to expansion, followed by deletion of V beta 8+ T cells, and the remaining cells are tolerant when stimulated in vitro . Comparable expansion and deletion of V beta 8 T cells occurs in CTLA4-Ig transgenic mice . However, in contrast to normal mice, the remaining V beta 8+ T cells from CTLA4-Ig transgenic mice are not anergic and remain responsive to superantigen in vitro.

J Bacteriol, 1996 Apr, 178(7), 2005 - 9
Physiology and interaction of nitrate and nitrite reduction in Staphylococcus carnosus; Neubauer H et al.; Staphylococcus carnosus reduces nitrate to ammonia in two steps . (i) Nitrate was taken up and reduced to nitrite, and nitrite was subsequently excreted . (ii) After depletion of nitrate, the accumulated nitrite was imported and reduced to ammonia, which again accumulated in the medium . The localization, energy gain, and induction of the nitrate and nitrite reductases in S . carnosus were characterized . Nitrate reductase seems to be a membrane-bound enzyme involved in respiratory energy conservation, whereas nitrite reductase seems to be a cytosolic enzyme involved in NADH reoxidation . Syntheses of both enzymes are inhibited by oxygen and induced to greater or lesser degrees by nitrate or nitrite, respectively . In whole cells, nitrite reduction is inhibited by nitrate and also by high concentrations of nitrite (> or = 10 mM) . Nitrite did not influence nitrate reduction . Two possible mechanisms for the inhibition of nitrite reduction by nitrate that are not mutually exclusive are discussed . (i) Competition for NADH nitrate reductase is expected to oxidize the bulk of the NADH because of its higher specific activity . (ii) The high rate of nitrate reduction could lead to an internal accumulation of nitrite, possibly the result of a less efficient nitrite reduction or export . So far, we have no evidence for the presence of other dissimilatory or assimilatory nitrate or nitrite reductases in S . carnosus.

Eur J Pharmacol, 1996 Mar 28, 299(1-3), 229 - 33
Cicaprost and the type IV phosphodiesterase inhibitor, rolipram, synergize in suppression of tumor necrosis factor-alpha synthesis; Greten TF et al.; Suppression of tumor necrosis factor-alpha (TNF) synthesis is one major target in pharmacological immunomodulation . We now showed the synergistic suppressive effect of the specific type IV phosphodiesterase inhibitor, rolipram, and of the stable prostacyclin analogue, cicaprost, on TNF synthesis . This effect was seen with lipopolysaccharide and Staphylococcus epidermidis as stimuli in human peripheral blood mononuclear cells and in whole blood . Lipopolysaccharide-induced TNF synthesis by mononuclear cells decreased from 3.4 ng/ml to 1.5 ng/ml in the presence of 100 nM rolipram and to 0.7 ng/ml in the presence of 10 nM cicaprost . The combination of both agents suppressed TNF synthesis more than 10-fold, to 0.3 ng/ml . Synergistic suppression was also demonstrated for TNF mRNA.

J Immunol Methods, 1996 Mar 28, 190(1), 39 - 49
Successful in vitro antigen-dependent activation of 24-hour-old peripheral blood lymphocytes; Owen JA et al.; We describe a simple, rapid and reproducible in vitro culture system in which human peripheral blood lymphocytes (PBLs), donated 24 h prior to initiation of culture can be stimulated to produce antigen-specific antibodies . Peripheral blood lymphocytes purified by Ficoll-Hypaque centrifugation were passed over a G10 Sephadex column and then activated in vitro in the presence of 0.003% staphylococcus Cowan A, 2.8 x 10(-6) M indomethacin and appropriate concentrations of tetanus toxoid antigen . After the first 24 h in culture, a five-fold concentrated supernatant from an allogeneic mixed lymphocyte culture was added . The cell surface phenotypes of the PBLs were analyzed by flow cytometry at the initiation and termination of culture, in order to provide a comprehensive characterization of the cellular composition of a successful in vitro stimulation system . Our results clearly show that the majority of peripheral blood B cells can be induced to an activated stage (blast transformation) and interleukin 2 (IL-2) receptor expression, following very simple manipulations of the lymphoid population . Tetanus toxoid-specific antibody production can be readily generated in this cell population . In contrast, T cells were not activated to express IL-2 receptors and reach blast transformation, and did not show appreciable proliferation . Our system provides a population of B cells producing antibodies of desired specificity which could be utilized for the generation of human hybridomas or could serve as a donor population for antibody engineering via the combinatorial library approach . Careful light scattering and cell surface phenotypic analyses of the cells entering, proliferating and differentiating in these cultures enabled several novel observations to be made.

Biochemistry, 1996 Mar 26, 35(12), 3857 - 64
High-pressure denaturation of staphylococcal nuclease proline-to-glycine substitution mutants; Vidugiris GJ et al.; Our recently reported pressure-jump relaxation kinetics experiments on staphylococcal nuclease folding and unfolding {Vidugiris et al . (1995) Biochemistry 34, 4909} demonstrated that both transitions exhibit positive activation volumes, with that of folding being much larger than that of unfolding . Thus high pressure denatures proteins by slowing the rate of folding more than that of unfolding . In the present work, we take advantage of the very slow folding and unfolding rates under pressure to examine the kinetics and volume changes along the reaction coordinate for protein folding-unfolding for an interesting set of mutants of staphylococcal nuclease: P42G, P47G, P117G, and the double mutant, P47G+P117G . Previous studies have shown that replacement of an individual proline residue at position 42, 47, or 117 by glycine leads to paradoxical protein stabilization against denaturation by guanidine chloride, high temperature, or high pressure . In order to observe unfolding over an attainable pressure range, guanidine hydrochloride was employed . Within experimental error, the activation volumes and equilibrium volume changes were independent of the concentration of this denaturant and our analysis of the rate constants is consistent with the generally accepted hypothesis that this denaturant acts both by increasing the rate of unfolding and decreasing the rate of folding . We show that the stabilization resulting from each of the proline-to-glycine substitutions arises primarily from a decrease in the unfolding rate, and to a small degree, from an increase in the folding rate . The changes in rate constants upon proline-to-glycine substitution can be modeled in terms of small stabilization of the unfolded state, a greater stabilization of the transition state, and a still greater stabilization of the folded state . Although the rates were found to change for all of the mutants in the set, no changes greater than experimental error were found in the corresponding equilibrium volume changes and activation volumes for folding and unfolding . At low pressures (well below the onset of unfolding) the pressure-jump relaxation profiles for wild type proteins (both Foggi and V8) showed kinetic complexity . Although the effect was attenuated somewhat in pressure-jump profiles of one proline-to-glycine mutant (P42G), its persistence in data from all the mutants studied leads us to conclude that its origin is not cis/trans peptide bond isomerization at proline 117, 47, or 42.

Proc Natl Acad Sci U S A, 1996 Mar 19, 93(6), 2539 - 44
Least activation path for protein folding: investigation of staphylococcal nuclease folding by stopped-flow circular dichroism; Su ZD et al.; Is the pathway of protein folding determined by the relative stability of folding intermediates, or by the relative height of the activation barriers leading to these intermediates? This is a fundamental question for resolving the Levinthal paradox, which stated that protein folding by a random search mechanism would require a time too long to be plausible . To answer this question, we have studied the guanidinium chloride (GdmCl)-induced folding/unfolding of staphylococcal nuclease {(SNase, formerly EC 3.1.4.7; now called microbial nuclease or endonuclease, EC 3.1.31.1} by stopped-flow circular dichroism (CD) and differential scanning microcalorimetry (DSC) . The data show that while the equilibrium transition is a quasi-two-state process, kinetics in the 2-ms to 500-s time range are triphasic . Data support the sequential mechanism for SNase folding: U3 <--> U2 <--> U1 <--> N0, where U1, U2, and U3 are substates of the unfolded protein and N0 is the native state . Analysis of the relative population of the U1, U2, and U3 species in 2.0 M GdmCl gives delta-G values for the U3 --> U2 reaction of +0.1 kcal/mol and for the U2 --> U1 reaction of -0.49 kcal/mol . The delta-G value for the U1 --> N0 reaction is calculated to be -4.5 kcal/mol from DSC data . The activation energy, enthalpy, and entropy for each kinetic step are also determined . These results allow us to make the following four conclusions . (i) Although the U1, U2, and U3 states are nearly isoenergetic, no random walk occurs among them during the folding . The pathway of folding is unique and sequential . In other words, the relative stability of the folding intermediates does not dictate the folding pathway . Instead, the folding is a descent toward the global free-energy minimum of the native state via the least activation path in the vast energy landscape . Barrier avoidance leads the way, and barrier height limits the rate . Thus, the Levinthal paradox is not applicable to the protein-folding problem . (ii) The main folding reaction (U1 --> N0), in which the peptide chain acquires most of its free energy (via van der Waals' contacts, hydrogen bonding, and electrostatic interactions), is a highly concerted process . These energy-acquiring events take place in a single kinetic phase . (iii) U1 appears to be a compact unfolded species; the rate of conversion of U2 to U1 depends on the viscosity of solution . (iv) All four relaxation times reported here depend on GdmCl concentrations: it is likely that none involve the cis/trans isomerization of prolines . Finally, a mechanism is presented in which formation of sheet-like chain conformations and a hydrophobic condensation event precede the main-chain folding reaction.

J Immunol, 1996 Mar 15, 156(6), 2178 - 85
Residues near the amino and carboxyl termini of staphylococcal enterotoxin E independently mediate TCR V beta-specific interactions; Lamphear JG et al.; Previous studies identified three COOH-terminal residues in staphylococcal enterotoxin E (SEE; Asp200, Pro206, and Asp207) that in part mediate TCR V beta recognition . We have identified an additional three residues near the NH2-terminus of SEE (Arg20, Asn21, and Ser24 that are needed in conjunction with these COOH-terminal residues to fully restore native levels of V beta-specific T cell proliferation . A staphylococcal enterotoxin A SEA-SEE hybrid molecule containing the NH2-terminal V beta determinants of SEE to activate alone exhibited V beta specificities of both SEA and SEE, indicating that these residues of SEE independently contribute to V beta recognition and do not obscure the native V beta determinants of SEA . These findings suggest that the ability of SEE to activate certain V beta-specific T cell subsets may result from multiple interactions with a single TCR beta-chain or perhaps by cross-linking two TCR . High affinity binding to HLA-DR1, a property of native SEA, was not altered in the SEA-SEE hybrid enterotoxins containing amino acid substitutions in regions 20 to 24 and 200 to 207, indicating that residues comprising the V beta determinants of SEE are separate from residues that contribute to HLA-DR1 binding affinity . Computer models of the predicted structure of SEE revealed that the V beta determinants of SEE are located on two adjacent solvent-exposed loops . Thus, the residues of SEE that mediate V beta recognition may coalesce to form a TCR binding site with specificities for multiple TCR beta-chains.

J Immunol, 1996 Mar 15, 156(6), 2133 - 42
Phenotype and function of CD4+ T cells in mice lacking invariant chain; Wong P et al.; Mice bearing a targeted disruption of the gene encoding the invariant chain (Ii) have provided a deeper understanding of the critical role that Ii plays in the assembly, transport, and peptide occupancy of MHC class II molecules . In this study, we have investigated the consequence of the altered class II expression in Ii-deficient (Ii zero) mice on the phenotype and function of their CD4+ T cells . As seen by others, these mice show a sharp reduction in the CD4+8- subset in the thymus and periphery . Furthermore, a large proportion of the peripheral CD4+, but not CD8+, T cells in Ii zero mice exhibit decreased surface TCR-alpha beta levels and express markers of T cell activation . Although the CD4+ T cells respond to mitogens, anti-CD3 mAbs, and alloantigens, they respond poorly to the bacterial superantigen staphylococcal enterotoxin B and do not respond to peptide and protein Ags . Analysis of reciprocal radiation bone marrow chimeras constructed using Ii zero and wild-type mice indicate that the lack of Ii in the thymus is responsible for the phenotype of the CD4+ T cells in mutant mice . These results suggest that the altered thymic peptide repertoire displayed by class II molecules in the absence of Ii has a dramatic impact on the selection of CD4+ T cells and their phenotype in the periphery.

Riv Eur Sci Med Farmacol, 1996 Mar-Apr, 18(2), 53 - 60
Infectious arterial aneurysms: patterns and treatment; Illuminati G et al.; PURPOSE: To evaluate patterns and evolution of treatment of infectious arterial aneurysms in a 15 year period . MATERIAL AND METHOD: Eight patients bearing 8 arterial aneurysms: 4 aorto-iliac, 1 of the internal carotid, 1 of the posterior tibial, 1 of the cubital, 1 of the internal carotid artery . For the aorto-iliac aneurysms treatment consisted in resection extra-anatomic by-pass in 2, "in situ" prosthetic grafting in the other 2 . Extra-abdominal aneurysms were treated by excision/"in situ" vein grafting in two cases and simple resection in other two cases . RESULTS: One post-operative death occurred, due to rupture of a ligated aortic stump . No death or major complication occurred after "in situ" treatment of aorto-iliac aneurysms and, overall, in extra-aortic aneurysms . CONCLUSIONS: Staphylococcus and miceti have become the most frequently encountered causative agents . "In situ" grafting together with aggressive antibiotic therapy became the preferred method in the recent years and yielded good results.

Antibiot Khimioter, 1996 Mar, 41(3), 29 - 31
{Effect of 2-methyl-4-amino-6-hydroxypyrimidine on the effectiveness of antibiotic therapy in experimental staphylococcal infection in the context of immunosuppression}; Ismagilova AF et al.; The experiments on mice with Staphylococcus infection at the background of immune suppression due to the treatment with prednisolone or imuran showed that the use of 2-methyl-4-amino-6-oxypyrimidine, a derivative of pyrimidine, increased the animal survival, their lifespan and the efficacy of the tobramycin therapy.

In Vitro Cell Dev Biol Anim, 1996 Mar, 32(3), 149 - 58
Establishment and characterization of a bovine mammary myoepithelial cell line; Zavizion B et al.; The thermolabile large T-antigen, encoded by the simian virus 40 early region mutant tsA58, was used to establish clonal cell lines (BMM-UV) from primary bovine myoepithelial cells . The BMM-UV cells have undergone more than 300 population doublings without any signs of senescence, and they contain the intranuclear large T antigen . At low confluency, they grow in a spindlelike manner and develop very long projections that most likely allow for communication of cells at a distance from each other . Establishment results in a decrease in the number of cells that contract in response to oxytocin compared with the parental nontransfected cells (20% versus 45%) . Oxytocin responsiveness of BMM-UV cells increases when the cells are cultured in a medium supplemented with staphylococcal proteases . Proliferation of BMM-UV cells increases when they are cultured in the presence of epidermal growth factor (10 ng/ml) or insulinlike growth factor I (50 ng/ml) . The BMM-UV cells may become a useful model to study growth properties, cell-to-cell communication, and the function of bovine mammary myoepithelial cells.

J AOAC Int, 1996 Mar-Apr, 79(2), 434 - 440
Rapid determination of neomycin by a microbiological agar diffusion assay using triphenyltetrazolium chloride; Yamamoto CH et al.; The standard, quantitative determination of neomycin activity by the agar diffusion method requires an 18 to 24 h incubation time . To reduce incubation time, an alternative method using triphenyltetrazolium chloride has been developed . The inhibition zone appears much earlier; hence, an effort was made to standardize it . This indicator develops a physical response, related to the biological one, after a determined period . A Staphylococcus epidermidis suspension inoculated into solid medium at a concentration low enough that growth is not visible can reduce the dye to formazan . There is enough contrast to read the inhibition zone optically after a 7 h incubation . There is no significant difference between standard curves for 7 and 24 h incubations . Comparative assays for some pharmaceutical drugs containing neomycin in different forms show that it is possible to reduce incubation time . This modification is valid because no dispersion of results was detected by statistical analysis, which indicates that they belong to the same population . Thus, a rapid microbiological assay of neomycin has been validated and standardized.

J Virol Methods, 1996 Mar, 57(1), 15 - 8
Demonstration of rabbit haemorrhagic disease virus antigen by Staphylococcus protein A coagglutination test; Peshev R et al.; The Staphylococcus protein A coagglutination test (Sp A COAT) was developed for the diagnosis of rabbit haemorrhagic disease (RHD) . Liver, spleen, lungs and kidneys from 176 rabbits dead from viral haemorrhagic disease as well as the same organs from 64 healthy animals were examined by Sp A COAT and haemaglutination test (HAT) . The Sp A COAT was specific and considerably more simple to carry out than the HAT, which made it very useful for rapid identification of RHD.

J Clin Microbiol, 1996 Mar, 34(3), 508 - 11
Impact of chlorhexidine-silver sulfadiazine-impregnated central venous catheters on in vitro quantitation of catheter-associated bacteria; Schmitt SK et al.; To assess the impact of the antiseptic effects of silver sulfadiazine-chlorhexidine-impregnated central venous catheters on catheter culture systems, a series of in vitro experiments was performed . Segments of antiseptic and non-antiseptic-impregnated catheters were sonicated in thioglycolate broth and removed . After the addition of 10(3) CFU of Staphylococcus epidermidis per ml, aliquots of catheter-exposed broth were subcultured onto blood agar at 15-min intervals . Decreased mean colony counts were noted at 45 min for broth exposed to antiseptic-impregnated catheters compared with the colony counts for broth exposed to non-antiseptic-impregnated catheters (170 versus 540 CFU/ml) . These effects, which were also demonstrated by the roll-plate method, were abrogated by the use of medium containing inhibitors of silver sulfadiazine and chlorhexidine . To assess the duration of the antiseptic effects, catheter segments were suspended for up to 14 days in phosphate-buffered saline, incubated with 10(6) CFU of S . epidermidis per ml, and cultured . Inhibition of bacterial growth by antiseptic-impregnated catheters disappeared after 14 days . These studies suggest that antiseptic compounds elute from catheters during broth- and solid medium-based culturing processes, making necessary the addition of inhibitors of these compounds in culture media . They further suggest that the antimicrobial effects of antiseptic-impregnated catheters wane within several days of placement.

Ann Pharmacother, 1996 Mar, 30(3), 288 - 90
Treatment of vancomycin-resistant staphylococcal infections; Christensen KJ et al.; The reports of vancomycin resistance, though sparse, cannot be ignored . They document evidence of emerging vancomycin resistance . Because of the absence of suitable alternatives and a poor current understanding of the mechanisms involved, much work is needed to prevent such resistance from becoming widespread . Only by understanding the mechanism(s) of resistance involved can we develop strategies to combat resistant strains.

Indian J Ophthalmol, 1996 Mar, 44(1), 19 - 21
An epidemic of viral acute haemorrhagic conjunctivitis in Delhi in 1994; Satpathy G et al.; An epidemic of acute haemorrhagic conjunctivitis affecting persons of all ages and both sexes occurred in Delhi and surrounding areas during the monsoon season of 1994 . The symptoms lasted on an average for 4-5 days . In some of the patients corneal involvement was observed . Conjunctival swabs from the affected patients were processed for viral antigen detection, virus isolation and bacterial culture and sensitivity . Viral antigen was detected in 62% (31/50) of the smears tested by indirect immunofluorescence assay . In 22 (44%) of the specimens Coxackie A 24 (Cox A 24) virus antigen and in 9 (18%) of the specimens Entero Virus 70 (EV 70) antigen were detected . In confluent monolayers of Hep 2 cells cytopathic virus was isolated in 10 (30.30%) of the 33 specimens processed . The isolated viruses were identified as either Cox A 24 (7 isolates) or EV 70 (3 isolates) using indirect immunofluorescence assay . Super added bacterial infection was observed in 33% (89/270) of the cases, Staphylococcus albus being the predominant bacteria isolated.

Immunology, 1996 Mar, 87(3), 428 - 33
The bacterial superantigen Staphylococcal enterotoxin B stimulates lymphocyte locomotor capacity during culture in vitro; Newman I et al.; The bacterial superantigen Staphylococcal enterotoxin B (SEB) was investigated for its effects on lymphocyte locomotion in vitro . Culture of peripheral blood mononuclear cells (PBMC) for 24-72 hr in SEB (1-100 micrograms/ml) increased the proportion of lymphocytes in locomotor (polarized) morphology and capable of invading collagen gels, to the same extent as the established locomotor activator, anti-CD3 (alpha-CD3), though the conventional antigen, tetanus toxoid was ineffective . The cells responding to SEB were predominantly T cells . SEB had no effect on lymphocyte locomotion in short-term (45 min) assays, thus its effect is to stimulate growth-related locomotor capacity and it does not act as a chemoattractant . During culture of PBMC in SEB, the chemokines interleukin-8 (IL-8) and macrophage chemotactic protein-1 (MCP-1) were released into the culture medium . The presence of anti-IL-8, but not of anti-MCP-1, either during culture or added to SEB culture supernatants and tested in short-term assays, inhibited the development of polarization suggesting that IL-8, which is a lymphocyte chemoattractant, also plays a key role in SEB-induced locomotor activation . Among SEB-activated lymphocytes, CD45RO+CD45RA- lymphocytes showed enhanced locomotor responses, but a relation was not found between locomotor activity and the presence of cell surface CD69.

Ann Cardiol Angeiol (Paris), 1996 Mar, 45(3), 113 - 8
{Multifactor prevention of endocarditis and cardiac pacemakers . A prospective study apropos of 207 patients}; Graux P et al.; Infections after cardiac pacemaker implantation are rare (0.13 to 12.6%) but potentially severe complications . Staphylococcus is the genus most frequently isolated (72 to 100% of cases) . The use of systematic prophylactic antibiotics remains controversial . From November 1991 to October 1993, 207 consecutive patients were submitted to a series of measures designed to reduce the risk of infection: a) intravenous bolus injection of Cefamindole, 15 minutes before implantation, b) cutaneous disinfection with iodinated polyvindone, c) injection of an ampoule of rifampin before closure of the pacemaker in the pouch, d) absence of drainage system . Patients were predominantly female (60.9%), with a mean age of 77 +/- 10 years, frequently suffering from heart disease (53.8%) . The indication for implantation was atrioventricular block (39.7%), carotid sinus syndrome (27.5%), atrial arrhythmia (27.5%), resection of the node-His tract (5.3%) . This procedure corresponded to the first implantation in 88.4% or replacement of a previous pacemaker in 11.6% of cases and the pacing mode was single-chamber (38.4% or replacement of a previous pacemaker in 11.6% of cases and the pacing mode was single-chamber (38.7%), or double chamber (61.3%) . The mean duration of the procedure was 51.5 min +/- 30 min . The mean follow-up was 12.7 +/- 5 months . The overall mortality was 14% (11 cases of cardiac failure, 6 sudden deaths, 4 cerebrovascular accidents, 4 cases of pneumonia, 4 neoplasms) . Only one infectious problem (endocarditis, i.e . 0.48%) was observed.

Lipids, 1996 Mar, 31 Suppl, S91 - 6
Modulation of antioxidant enzymes and programmed cell death by n-3 fatty acids; Fernandes G et al.; Studies from our laboratory indicate that n-3 (fish oil, FO) lipids at 10% (w/w) in a nutritionally adequate, semipurified diet, and supplemented with equal levels of antioxidants, extended the life span of lupus-prone (NZB/NZW)F1 (B/W) female mice as compared to n-6 (corn oil, CO) lipids . The early rise of autoimmune disease in CO-fed mice was closely linked to the loss of T-cell function . Both IL-2 production and IL-2 receptor expression were reduced due to the loss of naive T-cells and a rise in memory T-cells . Proliferative response to both mitogens and superantigens (staphylococcal enterotoxins A and B) was higher in FO-fed 6.5-mon-old mice . These changes paralleled decreased PGE2 production by splenic cells from FO-fed mice . Analysis of mRNA expression in different organs revealed differential effects of dietary lipids . In FO-fed mice, transforming growth factor beta 1 (TGF beta 1) expression was decreased in kidneys, but splenic tissues had higher expression of TGF beta mRNA . As TGF beta promotes programmed cell death (PCD), we studied the effects of CO and FO on PCD rates in lymphocytes . Both propidium iodide staining and DNA fragmentation were elevated in lymphocytes of FO-fed mice when compared to CO-fed mice of similar age . Also, increased PCD correlated closely with increased Fas gene expression . Thus, in addition to various other antiinflammatory effects, dietary FO appears to increase PCD and prevent accumulation of self-reactive immune cells in lymphoid organs . Further studies are required to dissect the pro- and antiinflammatory mechanisms associated with dietary n-3 and n-6 lipids in modulating autoimmune disorders or malignancy during aging.

Zh Mikrobiol Epidemiol Immunobiol, 1996 Mar-Apr, (2), 79 - 81
{The indices of interleukin 1, 2 and 4 production and the specific antibody titers in mice with an opposite sensitivity to staphylococcal infection}; Averbakh MM et al.; The data on a high level of interleukin production in mice, resistant to staphylococcal infection (CBA), in comparison with that in mice, sensitive to this infection (C3HA), are presented . The production of interleukin 1 in intact and infected mice of different strains exhibited no differences between these strains, but its level considerably increased after the inoculation of the animals . A the same time differences in the synthesis of IgM and IgG1 in intact and infected mice of different strains were noted.

Zh Mikrobiol Epidemiol Immunobiol, 1996 Mar-Apr, (2), 74 - 5
{The effect of an experimental staphylococcal infection on the morphofunctional characteristics of tissue basophils and mast cells}; Krasnozhenov EP et al.; In the process of staphylococcal infection in mice an increase in the number and functional activity of peritoneal, mesenterial and dermal basophils occurs . The preliminary activation of tissue basophils with equine serum albumin has favorable influence on the course of the infectious process, enhances the reaction of mast cells and phagocytes on the causative agent . The role played by tissue basophils in anti-infectious protection may be linked with the increased secretion of histamine producing a stimulating effect on the phagocytic mechanism of immunity.

Zh Mikrobiol Epidemiol Immunobiol, 1996 Mar-Apr, (2), 44 - 7
{The characteristics of the autoimmune reactions in donors immunized with influenza vaccine and staphylococcal anatoxin}; Krutitskaia LI et al.; Regularities in the formation of autoantibodies to human IgA, IgM, IgG and their fragments, such as F(ab')2, Fab, Fc, in donors immunized with influenza vaccine (44 subjects) and staphylococcal toxoid (15 subjects) were studied with regard to the dynamics of specific immune response . After immunization with staphylococcal toxoid autoimmune reactions were registered only in the precipitation tests during 3-5 weeks of observation . In donors immunized with influenza vaccine the induction of isotypically heterogeneous autoimmune reactions was established . These reactions were represented mainly by IgA and IgG autoantibodies to immunoglobulins of different classes and their fragments . The duration of autoimmune reactions registered in this group of donors was specially noteworthy . The levels of autoantibodies to most of the antigens under study remained significantly elevated for 6 months . After immunization with influenza vaccine the presence of direct correlation between the level of specific immune response and the level of autoantibody formation was established.

J Interferon Cytokine Res, 1996 Mar, 16(3), 225 - 36
Effect of staphylococcal enterotoxin B-induced anergy on cytokine gene expression: anergy-sensitive and resistant mRNA expression; Koide Y et al.; We examined the effect of staphylococccal enterotoxin B (SEB)-induced anergy on expression of six different cytokine genes in T cells restimulated with SEB in vitro . We found that although IL-2, IL-3, and IL-4 mRNA levels are substantially reduced in anergic T cells, mRNAs for IL-6, IL-10, IFN-gamma, and TNF-alpha are expressed normally . Thus, there appeared both anergy-sensitive and resistant cytokine mRNA expression in restimulated anergic T cells . The same pattern of cytokine mRNA responses was observed in anergic CD4+ T cells, indicating that the preferential induction of anergy in Th1-like cells is not evident in this in vivo model . Employing TCR V beta 8.2 transgenic mice in which almost all T cells become anergic, we found that the TCR/CD3 complex can transduce both anergy-sensitive and resistant signals . Furthermore, a series of experiments using FK506, A23187, and PMA suggests that signals between TCR and activation of calcineurin and protein kinase C may be blocked in anergic T cells . This is supported by our gel mobility shift assays indicating that calcineurin and/or PMA-inducible NF-ATp, OAP40, and AP-1, but not calcineurin-independent Oct-2, are repressed in anergic spleen T cells upon restimulation with SEB . Taken together, these results suggest that, among signals elicited by stimulation of TCR with SEB, a Ca2+/calcineurin-NF-ATp pathway and other signals, including protein kinase C, are repressed in anergic T cells upstream of their activation, which are essential for the cytokine mRNA expression of the anergy-sensitive type but are dispensible for those of the anergy-resistant type.

J Bone Joint Surg Br, 1996 Mar, 78(2), 213 - 6
Structural allograft in two-stage revisions for failed septic hip arthroplasty; Alexeeff M et al.; We report 11 patients having revision of total hip arthroplasty using massive structural allografts for failure due to sepsis and associated bone loss . All patients had a two-stage reconstruction and the mean follow-up was 47.8 months (24 to 72) . Positive cultures were obtained at the first stage in nine of the 11 patients, with Staphylococcus epidermidis being the most common organism . The other two patients had draining sinuses with negative cultures . There was no recurrence of infection in any patient . The mean increase in the modified Harris hip score was 45 and all the grafts appeared to have united to host bone . Two patients required additional procedures, but only one was related to the allograft . Complications included an incomplete sciatic nerve palsy and one case of graft resorption . Our results support the use of massive allografts in failed septic hip arthroplasty in which there is associated bone loss.

J Exp Med, 1996 Mar 1, 183(3), 857 - 66
An insulin peptide that binds an alternative site in class II major histocompatibility complex; Tompkins SM et al.; We report that a peptide from the B chain of insulin, B(10-30), binds with high affinity to multiple class II proteins, including IAb,d,k, IEd,k, and DR1 . The ability of B(10-30) to inhibit the binding of other peptide antigens to class II does not correlate with its affinity for class II . B(10-30) only weakly inhibits the binding of antigenic peptides . Conversely, peptides with high affinity for the peptide-binding groove of various class II proteins do not inhibit B(10-30) binding . The rate of association of B(10-30) with class II is unusually rapid, approaching saturation in 1-2 h compared with 1-2 d for classical peptide antigens in the same conditions . The dissociation rate is also relatively rapid . The B(10-30) peptide inhibits the binding of the super-antigen staphylococcal enterotoxin B (SEB) to IAk . It also inhibits SEB-mediated T cell activation . These observations support the conclusion that B(10-30) binds to a site outside the peptide-binding groove . Our findings indicate that short-lived peptide-class II complexes can be formed through interactions involving the SEB-binding site and raise the possibility that alternative complexes may serve as T cell receptor ligands.

J Exp Med, 1996 Mar 1, 183(3), 1083 - 92
Major histocompatibility complex class II-associated peptides control the presentation of bacterial superantigens to T cells; Wen R et al.; Recent studies have shown that only a subset of major histocompatibility complex (MHC) class II molecules are able to present bacterial superantigens to T cells, leading to the suggestion that class-II associated peptides may influence superantigen presentation . Here, we have assessed the potential role of peptides on superantigen presentation by (a) analyzing the ability of superantigens to block peptide-specific T cell responses and (b) analyzing the ability of individual peptides to promote superantigen presentation on I-Ab-expressing T2 cells that have a quantitative defect in antigen processing . A series of peptides is described that specifically promote either toxic shock syndrome toxin (TSST) 1 or staphylococcal enterotoxin A (SEA) presentation . Whereas some peptides promoted the presentation of TSST-1 (almost 5,000-fold in the case of one peptide), other peptides promoted the presentation of SEA . These data demonstrate that MHC class II-associated peptides differentially influence the presentation of bacterial superantigens to T cells.

Infect Immun, 1996 Mar, 64(3), 885 - 90
Biochemical and mutational analysis of the histidine residues of staphylococcal enterotoxin A; Hoffman M et al.; The goal of this study was to examine the role of histidine residues in the biological activities of staphylococcal enterotoxin A (SEA) . Carboxymethylated SEA was unable to stimulate murine T-cell proliferation but was resistant to monkey stomach lavage fluid degradation, suggesting that native conformation was intact . Site-directed mutagenesis of the histidine residues of SEA was subsequently performed . SEA-H44A (SEA with histidine 44 replaced with alanine), SEA-H44D, SEA-H50A, SEA-H50D, SEA-H114A, SEA-H114D, SEA-H187A, and SEA-H187D retained superantigen and emetic activities, whereas SEA-H225A and SEA-H225D were defective in the ability to stimulate T-cell proliferation . These mutants were unable to compete with SEA for binding to Raji cells, suggesting that the defect in SEA-H225A and SEA-H225D is due to impaired major histocompatibility complex class II binding . SEA-H225D provoked an emetic response in monkeys only if fed at high doses, while SEA-H225A did not provoke an emetic response at low or high doses . In comparison, SEA-H61A and SEA-H61D were defective in emetic activity but not in the ability to stimulate murine T-cell proliferation . Overall, these studies show that the carboxy-terminal histidine at residue position 225 of SEA is important for both the superantigen and emetic activities of this enterotoxin . Histidine 61 appears to be important for emetic activity but not for superantigen activity, consistent with the hypothesis that the two activities are separable in staphylococcal enterotoxins.

J Bacteriol, 1996 Mar, 178(5), 1335 - 40
Expression, purification, and characterization of EpiC, an enzyme involved in the biosynthesis of the lantibiotic epidermin, and sequence analysis of Staphylococcus epidermidis epiC mutants; Kupke T et al.; The plasmid-encoded epidermin biosynthetic gene epiC of Staphylococcus epidermidis Tu3298 was expressed in Escherichia coli by using the T7 RNA polymerase-promoter system, and the gene product EpiC was identified by Western blotting (immunoblotting) with an anti-EpiC-peptide antiserum . EpiC was a hydrophobic but soluble protein . EpiC was purified by hydrophobic-interaction chromatography . The determined amino-terminal amino acid sequence was M I N I N N I ... . The electrophoretic migration behavior of EpiC depended on the oxidation state of the enzyme, indicating the formation of an intramolecular disulfide bridge between C-274 and C-321 . The cysteine residues in the motifs WC-274YG and C-321HG of EpiC are conserved in all lantibiotic enzymes of the C type (so-called LanC proteins) and in the CylM protein . Mutated epiC genes from S . epidermidis epiC mutants were cloned and expressed in E . coli . Sequence analysis revealed that the mutations occurred in the two motifs -S-X-X-X-G-X-X-G- and -N-X-G-X-A-H-G-X-X-G-, which are conserved in all LanC proteins . For the investigation of EpiC-EpiA interactions, precursor peptide EpiA was coupled to N-hydroxysuccinimide-activated Sepharose High Performance Material (HiTrap) . Under reducing conditions, EpiC was retarded on the EpiA-HiTrap column . In the incubation experiments, EpiC did not react with EpiA, with proepidermin, or with oxidative decarboxylated peptides.

J Biomol NMR, 1996 Mar, 7(2), 131 - 41
High-level production of uniformly 15N- and 13C-enriched fusion proteins in Escherichia coli; Jansson M et al.; An approach to produce 13C- and 15N-enriched proteins is described . The concept is based on intracellular production of the recombinant proteins in Escherichia coli as fusions to an IgG-binding domain, Z, derived from staphylococcal protein A . The production method provides yields of 40-200 mg/l of isotope-enriched fusion proteins in defined minimal media . In addition, the Z fusion partner facilitates the first purification step by IgG affinity chromatography . The production system is applied to isotope enrichment of human insulin-like growth factor II (IGF-II), bovine pancreatic trypsin inhibitor (BPTI), and Z itself . High levels of protein production are achieved in shaker flasks using totally defined minimal medium supplemented with 13C(6)-glucose and (15NH4)2SO4 as the only carbon and nitrogen sources . Growth conditions were optimized to obtain high protein production levels and high levels of isotope incorporation, while minimizing 13C(6)-glucose usage . Incorporation levels of 13C and/or 15N isotopes in purifies IGF-II, BPTI, and Z were confirmed using mass spectrometry and NMR spectroscopy . More than 99% of total isotope enrichment was obtained using a defined isotope-enriched minimal medium . The optimized systems provide reliable, high-level production of isotope-enriched fusion proteins . They can be used to produce 20-40 mg/l of properly folded Z and BPTI proteins . The production system of recombinant BPTI is state-of-the-art and provides the highest known yield of native refolded BPTI.

Am Surg, 1996 Mar, 62(3), 203 - 6
When should the "infected" subcutaneous infusion reservoir be removed?
Barnes JR, Lucas N, Broadwater JR, Hauer-Jensen M.
Subcutaneous central venous infusion reservoirs (central venous catheters) are one of the primary devices for administration of intravenous chemotherapy . Usually these devices have few problems, and they provide dependable long term central venous access . Infection of these catheters is a significant problem that usually requires removal . When infection is suspected, it is often difficult to make this determination without actually removing the catheter . Thorough preoperative evaluation may help the surgeon decide which catheters are infected and should be removed . A total of 817 subcutaneous infusion reservoirs were placed at our institution from January 1, 1990 through November 1, 1994 . During the same time period, 143 catheters were removed, 63 for suspected infection . The charts of these 63 patients were reviewed to determine to what extent available preoperative information could be used to predict which catheters were infected, thus avoiding unnecessary removal . Twenty-three preoperative parameters were assessed, including physical exam, body temperature, leukocyte count, platelet count, blood cultures from the catheter and peripheral blood, time from placement to removal, whether or not the catheter was functional, and whether it was currently in use . Forty catheters (65%) removed for suspected infection were infected, as demonstrated by a positive culture from the catheter or the wound . Staphylococcus was the most common microorganism . Physical exam (local erythema, tenderness, or swelling) correlated significantly with catheter infection (P = 0.0238) . In contrast, blood culture data and the other clinical and laboratory parameters showed no significant association with catheter infection . We conclude that physical exam is the best indicator of catheter infection . Commonly used parameters such as fever, leukocytosis, and positive blood cultures are nonspecific, may not be due to catheter infection, and were not significant in our study . Removal and subsequent restoration of long term intravenous access is associated with significant morbidity and expense . Clinical decision making should not be based on isolated laboratory findings, but must be individualized in each patient with suspected catheter infection.

Eur J Immunol, 1996 Mar, 26(3), 618 - 22
The J beta segment of the T cell receptor contributes to the V beta-specific T cell expansion caused by staphylococcal enterotoxin B and Urtica dioica superantigens; Musette P et al.; We have used a new polymerase chain reaction-based technique to analyze at the clonal level the CDR3 diversity and the J beta usage associated with the V beta-dependent T cell receptor (TCR) recognition of two superantigens: the staphylococcal enterotoxin B and the Urtica dioica agglutinin . Our results show that subset of J beta elements is preferentially expanded in a given V beta family, independently of the nature of the superantigen . By contrast, the CDR3 loop does not contribute significantly to the T cell expansion induced by the superantigens . We conclude that the J beta segment of the TCR beta chain, but not the CDR3 region, participates in superantigen binding, presumably by influencing the quaternary structure of the TCR beta chain.

Am J Kidney Dis, 1996 Mar, 27(3), 409 - 15
Low-calcium peritoneal dialysis fluid should not impact peritonitis rates in continuous ambulatory peritoneal dialysis; de Fijter CW et al.; It has been suggested that reducing the calcium content of peritoneal dialysis fluid (PDF) to 2.5 mEq/L decreases peritoneal macrophage (PMO) function and increases the incidence of peritonitis (especially Staphylococcus epidermidis peritonitis) in continuous ambulatory peritoneal dialysis patients . We studied the uptake and killing of S epidermidis and Escherichia coli by PMOs and peripheral blood leukocytes incubated in control buffer (Hank's balanced salt solution containing 0.1% gelatin {GHBSS}) and PDF containing varying concentrations of calcium (O to 3.5 mEq/L) and magnesium (O to 1.5 mEq/L) using ether diamine tetraacetic acid and ethylenediaminetetraacetic acid chelation, respectively . In addition, interleukin-1-beta-induced interleukin-6 production by human mesothelial cells was measured in the presence of concentrations of calcium increasing from 0 to 3.0 mmol/L . Fc receptor- mediated uptake of S epidermidis by PMO in the complete absence of Ca++ was comparable to that by PMO incubated in GHBSS with calcium . In contrast, the complement-dependent uptake of E coli was significantly lower in GHBSS devoid of Ca++ (46% +/- 5% v 24% +/- 3%; 0.05 < P < 0.02) . No effect on intracellular killing of either microorganism by PMO was observed . The same held true for the phagocytic and killing capacity of polymorphonuclear granulocytes and monocytes obtained from healthy donors . Using Ca++ (2 to 3.5 mEq/L) and Mg++ (0.5 to 1.5 mEq/L) concentrations as applied in commercial PDFs, however, phagocytes performed as well as in control buffer . Interleukin-6 production by stimulated human mesothelial cells also required a small amount of Ca++ only, being normal above the 0.1 to 3 mmol/L Ca+ + range tested . Thus, complement- dependent uptake of bacteria by phagocytes is calcium dependent, whereas antibody-dependent uptake of S epidermidis is not . The concentrations of calcium in the current PDFs, however, will not compromise human mesothelial cells and leukocyte functions, and therefore should not impact the peritonitis rate.

Am J Kidney Dis, 1996 Mar, 27(3), 402 - 8
Tumor necrosis factor-alpha, interleukin-1 beta, and interleukin-1 receptor antagonist in dialysate and serum from patients on continuous ambulatory peritoneal dialysis; Brauner A et al.; Dialysate and serum levels of tumor necrosis factor-alpha (TNF-alpha), interleukin-1 beta (IL-1 beta), and IL-1-ra were investigated in 20 patients on continuous ambulatory peritoneal dialysis (CAPD), who altogether had 30 episodes of peritonitis . Bacterial growth was found in 25 (83%) of the dialysate samples . Staphylococcus epidermidis was the single most common microorganism, found in 44% of the culture-verified peritonitis . Samples from dialysate bags were obtained during the first month of dialysis and during peritonitis from the first three bags on day 1 (the day of admittance) and from night bags on days 3 and 10 . Serum samples were drawn on days 1 and 10 . The peak concentrations of cytokines occurred on the first day of infection . In dialysates, TNF-alpha was elevated in 96% of the patients, with a peak median concentration of 160 pg/mL (range, <15 to 4,400 pg/mL) . Seventy-five percent of the dialysates had elevated IL-1-beta, with the highest median level of 52 pg/mL (range, <10 to 940 pg/mL), whereas all patients had elevated IL-1 ra, with a peak median value of 10,300 pg/mL (range, 470 to 79,000 pg/mL) . TNF-alpha, IL-1 beta, and IL-Ira were significantly higher than in corresponding noninfected samples (TNF-alpha median value, <15 pg/mL; IL-1 beta, <10 pg/mL; and IL-1-ra, 150 pg/mL; P < 0.0001, P < 0.002, and P < 0.001, respectively) . In serum, elevated TNF-alpha levels were found in 92% of the episodes, but the median levels were less than one third of the corresponding lavage levels . IL-1-beta was detected in 8% of the episodes and, although IL-1-ra was found in 92% of the patients, the dialysate levels were more than 15 times higher . In dialysate, a correlation was observed for TNF-alpha and IL-Ira and also between IL-1-beta and IL-Ira . IL-1 beta and IL-1-ra also correlated with the previously analyzed IL-6, and IL-1-beta correlated with the previously analyzed IL-8 . Patients infected with high virulent strains had higher cytokine levels as compared with those infected with low virulent strains . In conclusion, our study shows markedly elevated TNF-alpha, IL-1 beta, and IL-1-ra levels in the acute stage in CAPD patients with peritonitis.

Scand J Immunol, 1996 Mar, 43(3), 277 - 82
Intravenous immunoglobulin (IVIg) modulates the expansion of V beta 3+ and V beta 17+ T cells induced by staphylococcal enterotoxin B superantigen in vitro; Baudet V et al.; The authors investigated the effect of IVIg on T-cell proliferation induced by the superantigen, staphylococcal enterotoxin B (SEB) . The addition of IVIg to normal PBMC stimulated with SEB resulted in a threefold increase in the proportion of CD3+ blast cells expressing V beta 3 and V beta 17, two subsets of T cells that selectively expand in the presence of SEB . There was no increase in the proportion of T-cell blasts expressing V beta 2, V beta 8 and V beta 13.6 antigens that do not respond to SEB in the absence of IVIg . As described previously, IVIg inhibited T-cell proliferation independently of V beta specificity . The effects of IVIg were mediated by variable regions of immunoglobulins since they were reproduced with F(ab')2 fragments of IVIg but not with purified Fc fragments of IgG . The observation that SEB-activated T cells are rescued from inhibition of proliferation by IVIg indicates that Mg modulates the effects of superantigen on T cells . These results may be of relevance for understanding the mechanisms underlying the effects of IVIg in patients with diseases in which T-cell superantigens are of pathophysiological significance.

Am J Ophthalmol, 1996 Mar, 121(3), 318 - 9
Coagulase-negative Staphylococcus endophthalmitis after cataract surgery with intraocular vancomycin; Townsend-Pico WA et al.; PURPOSE: We studied a case of postoperative coagulase-negative Staphylococcus endophthalmitis in a 79-year-old man who had undergone cataract extraction in which vancomycin had been used intraoperatively in the infusion fluid . METHODS: The medical records were reviewed for the clinical history, ocular findings, and the vitreous and anterior chamber culture results . RESULTS: Acute, postoperative coagulase-negative Staphylococcus endophthalmitis developed in the patient in whom vancomycin had been used intraoperatively in the infusion fluid . CONCLUSIONS: Restraint is urged in the prophylactic use of vancomycin in the infusion fluids.

J Immunol, 1996 Mar 1, 156(5), 1848 - 55
Mutations in human CD4 impair the functional interaction with different human and mouse class II isotypes and alleles; Fleury S et al.; The structure-function of the CD4-class II MHC interaction was investigated . Two functional assays were used to assess the responses of the 3DT52.5.8 murine T cell hybridoma expressing human CD4 (h-CD4) or murine CD4 (m-CD4) . First, we determined the responses of the CD4+ and CD4-effector cells toward DAP-3 cells co-expressing the cognate alloantigen H-2Dd together with several human (DRw52b, DR4-Dw4, DR2A, and DPw2) and murine (I-Ab, I-Ak, IA alpha b I-A beta k and I-Ek) class II alleles and isotypes . We found that h-CD4 and m-CD4 strongly enhance the T cell response to H-2Dd, demonstrating that interspecies CD4/class II interactions occur efficiently . Furthermore, mutations in h-CD4 at positions 19, 89, and 165 markedly reduced the interaction with both human class II and mouse class II, indicating that the structural features of this cross-species interaction are strongly conserved . This was further supported by the finding that a h-CD4 deletion mutant (deletion F43-S49) interacted with both human and murine class II . Moreover, as 3DT cells express the responsive V beta element for the bacterial superantigen staphylococcal enterotoxin B, a co-receptor assay was conducted . DAP-3 cells expressing only class II molecules were used as APCs to present staphylococcal enterotoxin B to h-CD4+ and m-CD4+ T cells . h-CD4 and m-CD4 were able to enhance the T cell response to staphylococcal enterotoxin B, further demonstrating the conservation of the CD4-class II MHC interaction.

Transplantation, 1996 Feb 27, 61(4), 649 - 51
Evidence that orthotopic transposition following rat heterotopic small bowel transplantation corrects overgrowth of potentially pathogenic bacteria; Price BA et al.; An overgrowth of pathogenic organisms occurs following rat heterotopic small bowel transplantation . This study assessed whether the bacterial microflora return to normal following subsequent orthotopic transposition of the graft . After 14 days the heterotopic graft was placed into continuity following resection of 15 cm of the host midintestinal loop . Quantitative and qualitative analyses of the intraluminal bacteria were performed studying the resected host intestine, the heterotopic graft at 14 days, and the graft 14 days after transposition . A group of normal rats were used as controls . An overgrowth of Staphylococcus epidermidis evident in the heterotopic graft at 14 days returned to a more normal bacterial profile following orthotopic transposition . These findings suggest that early interposition of a small bowel graft into an orthotopic position may prevent an alteration in the small bowel ecology toward potentially pathogenic organisms capable of translocation.

Mol Gen Genet, 1996 Feb 25, 250(3), 375 - 9
Cloning and sequencing of two genes from Staphylococcus carnosus coding for glucose-specific PTS and their expression in Escherichia coli K-12; Christiansen I et al.; Phosphoenolpyruvate (PEP)-dependent phosphorylation experiments have indicated that the gram-positive bacterium Staphylococcus carnosus possesses an EIICBA fusion protein specific for glucose . Here we report the cloning of a 7 kb genomic DNA fragment containing two genes, glcA and glcB, coding for the glucose-specific PTS transporters EII(Glc)1 and EII(Glc)2 which are 69% identical . The translation products derived from the nucleotide sequence consist of 675 and 692 amino acid residues and have calculated molecular weights of 73025 and 75256, respectively . Both genes can be stably maintained in Escherichia coli cells and restore the ability to ferment glucose to ptsG deletion mutants of E . coli . This demonstrates the ability of the PTS proteins HPr and/or EIIA(Glc) of a gram-negative organism (E . coli) to phosphorylate an EIICBA(Glc) from a gram-positive organism (S . carnosus).

Transplantation, 1996 Feb 15, 61(3), 430 - 4
Nosocomial coagulase-negative staphylococcal infections in bone marrow transplantation recipients with central vein catheter . A 5-year prospective study; Engelhard D et al.; The purpose of this study was to examine coagulase-negative staphylococcal infections in bone marrow transplantation (BMT) patients with central vein catheters by investigating incidence, clinical relevance, risk factors, methicillin resistance, clinical impact of initial empiric antimicrobial therapy without vancomycin, and management of documented catheter-related infections . A 5-year prospective study was conducted with daily evaluation of 242 BMT patients during hospitalization, including clinical assessment and blood culture via the Hickman/Broviac catheter . If fever or infected appearance occurred, peripheral blood cultures or exit site cultures, respectively, were done . Results showed a septicemia incidence of 7.0%, including in 6 patients following colonization, in 1 patient with tunnel infection, in 1 patient with thrombophlebitis, in 1 patient with exit site infection, and in 8 patients with septicemia of unknown origin . Total colonization incidence was 7%, with colonization only in 11 patients who had 16 episodes; incidence of exit site infection was 3.7% . Age > or = 18 years was the only identified risk factor for developing staphylococcal infection (P = 0.03) . Despite a methicillin resistance rate of 45% and omission of vancomycin from the routine initial empiric antimicrobial regimen, the clinical course of coagulase-negative staphylococcal infections was relatively benign . A single patient, who experienced marrow rejection, died on day +31 with septicemia and only one patient experienced microbiological failure with recurrent colonization . Bacteria grown in both aerobic and anaerobic bottles were more likely true bacteremia than contaminant (P = 0.03) . We conclude that the hazard of coagulase-negative staphylococcal infection does not mandate inclusion of a glycopeptide in the initial empiric antimicrobial regimen in BMT patients, even during febrile neutropenia . Hickman/Broviac-related staphylococcal infections, except for tunnel infection or thrombophlebitis, can usually be treated successfully without removing the catheter.

J Immunol, 1996 Feb 15, 156(4), 1646 - 53
In vivo blockade of TNF-alpha by intravenous infusion of a chimeric monoclonal TNF-alpha antibody in patients with rheumatoid arthritis . Short term cellular and molecular effects; Lorenz HM et al.; Due to the unknown etiology of RA, specific treatment is not available . Recently, in a double-blinded, placebo-controlled clinical trial, in vivo blockade of TNF-alpha by a single infusion of a chimeric TNF-alpha-blocking mAb, cA2, has proven to be highly effective in the treatment of RA . In parallel to this trial, we tested the consequences of cA2 infusion in ex vivo and in vitro experiments . In this paper, we describe an increase in CD4+ and CD8+ T lymphocyte counts on day 1 and a marked decrease in monocyte counts preferentially on day 7 after cA2 treatment, without major changes in B lymphocyte or NK cell counts . In addition, we found an increased responsiveness of PBMC to CD28 mAb/PMA, but not to CD3 mAb, superantigen staphylococcus enterotoxin B, or PHA on day 1 after infusion . The increase in DNA synthesis of PBMC was paralleled by increased IL-2 mRNA and IL-4 mRNA expression and IL-2 protein secretion in culture supernatants after in vitro stimulation of PBMC with CD28 mAb/PMA . In PBMC, we did not find any significant changes in mRNA or protein expression of CD28 Ag or CD28 ligands, B7-1 and B7-2 . Serum concentrations of IL-1 beta, IL-6, and soluble CD14 were significantly diminished after in vivo TNF-alpha blockade . We did not see relevant changes in granulocyte function in vitro after cA2 infusion . Finally, we observed a statistically significant decrease in slCAM-1 molecules in the serum of patients treated with verum compared with that in the serum of subjects given placebo . This change in slCAM-1 concentration was evident on days 1 and 7 after the infusion of 10 mg/kg cA2, whereas it occurred only on day 7 in the serum of patients treated with the low dose (1 mg/kg) of cA2.

J Immunol, 1996 Feb 15, 156(4), 1378 - 86
Stat1 implication in the immune response to superantigens in vivo; Gimeno R et al.; We analyzed the activation and changes in the protein level of STAT1 as a consequence of in vivo treatment with superantigens . Ninety minutes after i.p . injection of the staphylococcal enterotoxin B (SEB), a complex containing STAT1 that was able to specifically bind to DNA containing GAS-like sequences was activated in mouse splenocytes . This complex had the same characteristics as that induced by IFN-gamma in several in vitro systems . Activation of the complex was inhibited by cyclosporin A, and Abs against IFN-gamma severely decreased the amount of complex detected . When splenocytes were analyzed 24 h after SEB treatment, a high increase in the amount of the STAT1 isoforms, STAT91 and STAT84, was observed by Western analysis, but binding to GAS-like sequences was clearly decreased when compared with analysis at 90 min . Nevertheless, when SEB was injected a second time 24 h after the first injection, the binding of STAT1 to GAS-like sequences had risen again . This approach corroborates the implication of IFN-gamma in the response to superantigens in vivo and shows the relevance of analysis of transcription factors in defining the molecular events involved in the immune response.

Proc Natl Acad Sci U S A, 1996 Feb 6, 93(3), 979 - 84
In vivo anergized CD4+ T cells express perturbed AP-1 and NF-kappa B transcription factors; Sundstedt A et al.; Anergy is a major mechanism to ensure antigen-specific tolerance in T lymphocytes in the adult . In vivo, anergy has mainly been studied at the cellular level . In this study, we used the T-cell-activating superantigen staphylococcal enterotoxin A (SEA) to investigate molecular mechanisms of T-lymphocyte anergy in vivo . Injection of SEA to adult mice activates CD4+ T cells expressing certain T-cell receptor (TCR) variable region beta-chain families and induces strong and rapid production of interleukin 2 (IL-2) . In contrast, repeated injections of SEA cause CD4+ T-cell deletion and anergy in the remaining CD4+ T cells, characterized by reduced expression of IL-2 at mRNA and protein levels . We analyzed expression of AP-1, NF-kappa B, NF-AT, and octamer binding transcription factors, which are known to be involved in the regulation of IL-2 gene promoter activity . Large amounts of AP-1 and NF-kappa B and significant quantities of NF-AT were induced in SEA-activated CD4+ spleen T cells, whereas Oct-1 and Oct-2 DNA binding activity was similar in both resting and activated T cells . In contrast, anergic CD4+ T cells contained severely reduced levels of AP-1 and Fos/Jun-containing NF-AT complexes but expressed significant amounts of NF-kappa B and Oct binding proteins after SEA stimulation . Resolution of the NF-kappa B complex demonstrated predominant expression of p50-p65 heterodimers in activated CD4+ T cells, while anergic cells mainly expressed the transcriptionally inactive p50 homodimer . These alterations of transcription factors are likely to be responsible for repression of IL-2 in anergic T cells.

J Immunoassay, 1996 Feb, 17(1), 1 - 12
Detection of adhesion of superantigen-activated T lymphocytes to human endothelial cells by ELISA; Krakauer T; A sensitive ELISA using monoclonal antibodies (mAb) reactive with surface molecules specific for various leukocytes was devised to measure the adhesion of these cells to cultured monolayers of human umbilical vein endothelial cells . Superantigens, staphylococcal enterotoxin B or toxic shock syndrome toxin 1 were used to activate human peripheral blood mononuclear cells . The extent of adhesion of these cells to endothelial cells was assayed by measuring the optical density produced by a complex of peroxidase-labeled streptavidin, biotin-conjugated F(ab')2 antimouse Ig and monoclonal antibody specific for leukocytes on fixed leukocytic cells that had adhered to endothelial cells . This method was fast and sensitive, and because the detection is by a specific marker on the cell of interest, it can be used in preparations of unseparated mixtures of cells . An increase in adhesion of superantigen-activated CD4+ and CD8- T lymphocytes to endothelial cells may contribute to the pathologic mechanism of superantigens.

J Protein Chem, 1996 Feb, 15(2), 131 - 6
Mustard gas crosslinking of proteins through preferential alkylation of cysteines; Byrne MP et al.; Mustard gas, bis(2-chloroethyl)sulfide, treatment of proteins is shown to generate significant amounts of covalently crosslinked protein dimers . This is due to the preferential alkylation of cysteine residues . Crosslinking does not occur in the model protein staphylococcal nuclease, which has no cysteine residues . Treatment of cysteine-containing mutants of staphylococcal nuclease with this chemical warfare agent did result in crosslinking . However, these dimers are slowly cleaved back to monomers by an unknown mechanism . The alkylation and crosslinking of cysteine-containing proteins by mustard gas may contribute to its toxicity.

J Dermatol Sci, 1996 Feb, 11(2), 104 - 10
Superantigen-induced cytokine expression in organ-cultured human skin; Matsunaga T et al.; Bacterial superantigen such as staphylococcal enterotoxin B (SEB) induced strong ICAM-1 expression in organ-cultured human keratinocytes . Other superantigens (SEA, SEC1, SEC2) but not mite antigen (Dermatophagoides) also induced ICAM-1 expression both at protein and mRNA level . In contrast to ICAM-1, vascular endothelial cell expression of VCAM-1 was only demonstrated at mRNA level following ICAM-1 expression in keratinocytes . Patterns of cytokine expression in keratinocytes were variable . TNF alpha was strongly expressed in keratinocytes both at protein and mRNA level, while IL1 beta and IL1 alpha were only demonstrated at mRNA level . These results clearly demonstrated that bacterial superantigen could induce cell adhesion molecule expression in keratinocytes through the induction of various cytokines and play an important role in the induction of refractory eczematous lesions in atopic dermatitis.

Nippon Ika Daigaku Zasshi, 1996 Feb, 63(1), 22 - 30
Characteristic immunological tolerance in intrahepatic lymphocytes induced by bacterial superantigen SEB; Matsui S et al.; We have reported that the liver is closely associated with the hematolymphoid system and that the liver, as a lymphoid organ, may play an important role in the differentiation of lymphocytes and oral tolerance . To investigate the relevance of the liver to immunological tolerance, we compared the response pattern to Staphylococcus enterotoxin B (SEB) in intrahepatic lymphocytes (IHL) with those of spleen cells (SPC) and mesenteric lymph node cells (mLNC) during tolerance induction . Tolerance was induced by i.v . injections of SEB in all three organs . IHL had a distinct pattern from the other cells in the induction of unresponsiveness to SEB . While SPC and mLNC have a proliferation phase before the reduction of DNA synthesis, IHL become tolerant immediately without this phase . When IHL became tolerant in the early period after SEB injection, their nylon-wool column non-adherent (NW-NA) IHL were not recovered from unresponsiveness in vitro in spite of the addition of irradiated normal SPC as accessory cells . NW-NA IHL did not secrete IL-2 during this process, indicating that NW-NA IHL were in a state of functional anergy soon after the i.v . administration of SEB . Phenotypic analysis revealed that the characteristic changes of IHL during the induction of unresponsiveness might be associated with the kinetic modulation of CD4+ V beta 8+ T cells . These results suggest that the liver may hold a different mechanism for the induction of tolerance to SEB from that of SPC and mLNC.

Kansenshogaku Zasshi, 1996 Feb, 70(2), 206 - 10
{A case of staphylococcal scalded skin syndrome caused by exfoliative toxin-B producing MRSA}; Yokota S et al.; We experienced a 6 month-old infant who suffered from staphylococcal scalded skin syndrome (SSSS), whose mother used steroid ointment for the infant's erythematous skin rash for 2 days . On the 3rd day, the infant was admitted to our hospital with fever, erythema on the trunk and extremities, and flaccid blisters and erosions at periorificial areas and the neck . Nikolsky's sign was positive . S . aureus was cultured from the throat, conjunctival inflammatory lesion and exudates . The biological characteristics of the isolates were coagulase type I, enterotoxin-nonproducing, TSST-1-nonproducing, protease pattern: D type, and plasmid profile: 563 kbp . The investigation of exfoliative toxin (ET) revealed negative for ET-A but positive for ET-B, proved by polymerase chain reaction (PCR) . The isolated strain of S . aureus was demonstrated to be methicillin-resistant (MRSA), which was further defined to be positive for mec A gene by PCR method . It will be possible for such toxigenic ET-B producing MRSA to gain the dominant status in NICU or closed areas.

Biol Pharm Bull, 1996 Feb, 19(2), 224 - 7
The macrolide antibiotic, roxithromycin suppresses IFN-gamma-mediated immunological functions of cultured normal human keratinocytes; Wakita H et al.; The effects of the macrolide antibiotic, roxithromycin (RXM) on immunological functions of cultured normal human keratinocytes (NHK) were studied . RXM neither modulated the expression of intercellular adhesion molecule-1 (ICAM-1) and human histocompatibility leukocyte antigen (HLA)-DR nor mobilized intracellular free calcium in NHK that were cultured in medium alone . However, the ICAM-1 and HLA-DR expression induced by cultivation with interferon-gamma (IFN-gamma) was upregulated and suppressed, respectively, by pretreatment of NHK with RXM . Whereas ICAM-1 upregulation was observed with RXM at a concentration as high as 0.1 mM, the inhibition of HLA-DR expression by RXM was virtually dose-dependent at doses ranging from 100 nM to 0.1 mM . Accessory cell function of major histocompatibility complex (MHC) class II-bearing NHK in terms of the T-cell response to staphylococcal enterotoxin B was suppressed by pretreatment of NHK with RXM, indicating the functional consequence of RXM-induced reduction of MHC class II molecules . Furthermore, RXM inhibited IFN-gamma-mediated upregulation of IL-1 alpha secretion by NHK . These results show that RXM suppresses immunological functions of keratinocytes triggered by IFN-gamma and suggest the therapeutic relevance of RXM to T cell-mediated inflammatory skin diseases and T cell malignancies such as atopic dermatitis, psoriasis and cutaneous T cell lymphoma, which can be exacerbated by keratinocytes immunologically modulated by exposure to IFN-gamma.

Eur J Clin Microbiol Infect Dis, 1996 Feb, 15(2), 133 - 8
Increased resistance among Staphylococcus epidermidis isolates in a large teaching hospital over a 12-year period; Lyytikainen O et al.; The prevalence of drug resistance among clinically significant blood isolates of Staphylococcus epidermidis (n = 464) and consumption of antibiotics at a tertiary care teaching hospital (Meilahti Hospital, Helsinki) were analysed for the period 1983-1994 . Resistance to methicillin increased from 28 to 77% . Simultaneously, usage of third-generation cephalosporins increased nearly sevenfold (from 8.6 kg/ to 56.4 kg/year) . A significant correlation was found between percentages of methicillin resistance and usage of penicillinase-stable beta-lactam agents, including cloxacillin, imipenem, and first-, second-, and third-generation cephalosporins (r = 0.737, p < 0.0062) . The increase in ciprofloxacin resistance occurred soon after the introduction of ciprofloxacin . Moreover, there was a remarkable increase in resistance to fusidic acid (from 10 to 40%) and rifampin (from 0 to 23%) despite the low usage of these agents . Overall, the rate of multiply resistant isolates roughly tripled (from 20 to 71%) and, by 1994, the frequency of isolates susceptible to vancomycin only was as high as 11%, which remarkably limits options for therapy.

J Am Soc Nephrol, 1996 Feb, 7(2), 218 - 24
In vitro effects of bicarbonate and bicarbonate-lactate buffered peritoneal dialysis solutions on mesothelial and neutrophil function; Topley N et al.; The inclusion of bicarbonate in the formulation of peritoneal dialysis solutions may avoid the in vitro impairment of certain cell functions seen with acidic lactate-based fluids . The supranormal physiological levels of HCO3- and PCO2 inherent in such formulations may, however, not be biocompatible . This study compared the in vitro biocompatibility of a pH 5.2 lactate-based formulation with formulations containing either 40 mM lactate at pH 7.4, 38 mM HCO3- at pH 6.8 (PCO2 at approximately 240 mm Hg) or 7.4 (PCO2 at approximately 60 mm Hg), and 25 mM HCO3- plus 15 mM lactate at pH 6.8 (PCO2 at approximately 160 mm Hg) or 7.4 (PCO2 at approximately 40 mm Hg) . Significant release of lactate dehydrogenase or decreases in ATP content by human peritoneal mesothelial cells (HPMC) and human peripheral polymorphonuclear leukocytes (PMN) after a 30-min exposure to each test solution was only seen with the pH 5.2 lactate-based fluid . The ATP content of HPMC exposed to this fluid returned to control levels after 30 min of recovery in M199 control medium but showed a trend toward decreasing ATP content at 240 min . Similarly, interleukin (IL)-1 beta-induced IL-6 synthesis by HPMC was also only significantly reduced by the pH 5.2 lactate solution . PMN chemiluminescence was unaffected by 30-min exposure to all test solutions except for the pH 5.2 lactate formulation . Staphylococcus epidermidis phagocytosis was reduced to between 46 to 57% of control with all test solutions except the pH 5.2 lactate solution, which further suppressed the chemiluminescence response to 17% of control . These data suggest that short exposure to supranormal physiological levels of HCO3- and PCO2 does not impair HPMC or PMN viability and function . Furthermore, neutral pH lactate-containing solutions show equivalent biocompatibility to bicarbonate-based ones.

Antonie Van Leeuwenhoek, 1996 Feb, 69(2), 119 - 127
The biosynthesis of the lantibiotics epidermin, gallidermin, Pep5 and epilancin K7; Bierbaum G et al.; Lantibiotics are antibiotic peptides that contain the rare thioether amino acids lanthionine and/or methyllanthionine . Epidermin, Pep5 and epilancin K7 are produced by Staphylococcus epidermidis whereas gallidermin (6L-epidermin) was isolated from the closely related species Staphylococcus gallinarum . The biosynthesis of all four lantibiotics proceeds from structural genes which code for prepeptides that are enzymatically modified to give the mature peptides . The genes involved in biosynthesis, processing, export etc . are found in gene clusters adjacent to the structural genes and code for transporters, immunity functions, regulatory proteins and the modification enzymes LanB, LanC and LanD, which catalyze the biosynthesis of the rare amino acids . LanB and LanC are responsible for the dehydration of the serine and threonine residues to give dehydroalanine and dehydrobutyrine and subsequent addition of cysteine SH-groups to the dehydro amino acids which results in the thioether rings . EpiD, the only LanD enzyme known so far, catalyzes the oxidative decarboxylation of the C-terminal cysteine of epidermin which gives the C-terminal S-aminovinylcysteine after addition of a dehydroalanine residue.

Immunology, 1996 Feb, 87(2), 264 - 70
Oral aspirin and ibuprofen increase cytokine-induced synthesis of IL-1 beta and of tumour necrosis factor-alpha ex vivo; Endres S et al.; We investigated the effect of oral aspirin and ibuprofen on the ex vivo synthesis of interleukin-1 alpha (IL-1 alpha), IL-1 beta, IL-2, IL-6, tumour necrosis factor-alpha (TNF) and granulocyte-macrophage colony-stimulating factor (GM-CSF) by stimulated peripheral blood mononuclear cells (PBMC) from healthy volunteers . Seven volunteers took 325 mg of aspirin daily for 14 days . Three weeks after ending aspirin medication, ex vivo IL-1 beta and TNF synthesis induced by exogenous IL-1 alpha was elevated threefold compared to the pre-aspirin value (P = 0.01 and P = 0.005, respectively) . Using lipopolysaccharide (LPS) as a stimulus, no influence of oral aspirin was observed . The increase in cytokine synthesis did not parallel decreased synthesis of prostaglandin E2 (PGE2) . Seven weeks after discontinuation of aspirin, cytokine and PGE-2 production returned to pre-aspirin levels . Another seven volunteers took 200 mg of ibuprofen daily for 12 days . Again, there was no effect on LPS- or Staphylococcus epidermidis-induced cytokine synthesis . However, IL-1 alpha-induced synthesis of IL-1 beta was elevated to a mean individual increase of 538% (P < 0.001) and synthesis of TNF was elevated to 270% (P < 0.001) at the end of ibuprofen medication and 2 weeks after discontinuation of ibuprofen . There were parallel increases in PGE2 and both returned to their pre-ibuprofen levels 5 weeks after stopping . Although inhibitors of cyclo-oxygenase blunt PGE2-mediated symptoms such as fever and pain, we conclude that short term use of either aspirin or ibuprofen results in a 'rebound' increase in cytokine-induced cytokine synthesis that is not observed in LPS-induced cytokines.

Immunology, 1996 Feb, 87(2), 191 - 7
Modulation of superantigen-induced T-cell deletion by antibody anti-Pgp-1 (CD44); Ayroldi E et al.; We examined the effects of anti-Pgp-1 (CD44) antibody on the in vitro deletion of murine CD4 and CD8 single positive T cells induced by Staphylococcal enterotoxin B (SEB) . Soluble anti-Pgp-1 antibody enhanced the apoptosis and decreased the proliferation of SEB-responding T cells . In contrast, cross-linked anti-Pgp-1 antibody provided costimulatory signals for the T-cell activation induced by anti-CD3 antibody . Hyaluronic acid (HA), a ligand of Pgp-1, did not affect proliferation and deletion induced by SEB, whereas it mimicked the effects of the cross-linked antibody in anti-CD3-driven proliferation . T-cell Pgp-1 surface expression after 48 hr incubation with SEB was unchanged as compared to unstimulated cells . However, when the memory T cells were established, some V beta 8+ (SEB-specific) T cells Pgp-1low became Pgp-1high, displaying a bimodal character . Moreover, the Pgp-1 increased expression correlated with an increase of Pgp-1 soluble form in the supernatant . These findings suggested that signals following the triggering of the Pgp-1 molecule are important in controlling T-cell survival.

J Am Acad Dermatol, 1996 Feb, 34(2 Pt 2), 368 - 74
CD7-positive Sézary syndrome with a Th1 cytokine profile; Yagi H et al.; Sezary syndrome is a leukemic variant of cutaneous T-cell lymphoma characterized by the appearance of numerous CD4+ cells with cerebriform nuclei in the peripheral blood . Recent observations have suggested that Sezary cells lack CD7 molecules on their surface and are analogous to murine Th2 cells . It remains unclear, however, whether these two properties are actually common features of Sezary cells . We describe a case of Sezary syndrome in which more than 98% of the peripheral blood mononuclear cells expressed CD7 as well as a homogeneous T-cell receptor V alpha 2V beta 17, indicative of the expression of CD7 in the Sezary cells . Although the circulating Sezary cells continuously bore CD7 molecule on their surface throughout the patient's clinical course, the intensity of CD7 expression was variable in skin-infiltrating and in vitro cultured cells . Peripheral blood mononuclear cells from the patient proliferated well to a V beta 17-relevant superantigen (staphylococcal enterotoxin B) but not to irrelevant superantigens; produced interleukin-2, interferon gamma, and tumor necrosis factor-alpha, but not interleukin-4; and transcribed messenger RNA for interleukin-2 and interferon gamma but not interleukin-4 or interleukin-10 . This represents an unusual case of a CD7+ Sezary syndrome with a cytokine profile characteristic of Th1 cells.

J Neuroimmunol, 1996 Feb, 64(2), 209 - 17
Copolymer 1 inhibits chronic relapsing experimental allergic encephalomyelitis induced by proteolipid protein (PLP) peptides in mice and interferes with PLP-specific T cell responses; Teitelbaum D et al.; Copolymer 1 (Cop 1) is a synthetic amino acid copolymer effective in suppression of experimental allergic encephalomyelitis (EAE) and developed as a candidate drug for multiple sclerosis (MS) . In the present study, we induced chronic relapsing (CR)-EAE in (SJL/J X BALB/c)F1 mice by either whole spinal cord homogenate or two synthetic peptides of proteolipid protein (PLP), p139-151 and p178-191 . When Cop 1 was added to the encephalitogenic inoculum, mice were almost completely resistant to disease induction . T cell lines to p139-151 and p178-191 were specific to these peptides . Their antigen-specific responses were inhibited by Cop 1 in a dose-dependent manner, while their polyclonal response to the superantigen staphylococcal enterotoxin A (SEA) was not affected by Cop 1 . Using biotinylated PLP derivatives, we demonstrated that the two PLP peptides bound to I-A(s) molecules, and that their binding was completely inhibited by unlabelled Cop 1 . Furthermore, Cop 1 could displace the PLP peptides from the MHC binding site . These results support the potential of Cop 1 as a broad-spectrum drug for MS.

Acta Chir Belg, 1996 Feb, 96(1), 3 - 10
Surgical wound infection surveillance: results from the Belgian hospital network; Ronveaux O et al.; Since October 1992, the Belgian National Programme for the Surveillance of Hospital Infections has been implemented successfully in more than two-thirds of all Belgian acute-care institutions . Practitioners from hospitals participating in the surgical wound infection surveillance describe a selection of surgical procedures, practices connected (antimicrobial prophylaxis), and record the eventual infection, enabling the calculation of wound infection rates . The network allows comparisons of each hospital results with the national picture . From October 1992 to June 1993, 16,799 procedures were recorded by 51 hospitals; the crude incidence rate of infection was 1.47 per 100 operations . However, this figure may be an underestimation of the reality because of potentially missed post-discharge infections . Risk factors significantly associated with infection include length of preoperative stay, emergency, duration of surgery, wound contamination class, and American Society of Anesthesiologists (ASA) score . The National Nosocomial Infections Surveillance system (NNIS) risk index, a combination of the three latter shows a good correlation for predicting infection . Increased length of stay attributable to the infection was computed at 8.9 days . Micro-organisms isolated reveal a staphylococcal predominance . Antibiotic prophylaxis prescription present satisfactory quality performances regarding duration and time of initiation but rational prescribing about the indications is still of concern.

J Exp Med, 1996 Feb 1, 183(2), 431 - 7
Peripheral T cells undergoing superantigen-induced apoptosis in vivo express B220 and upregulate Fas and Fas ligand; Renno T et al.; Staphylococcal enterotoxin B (SEB) is a bacterial superantigen (SAg) that predominantly interacts with V(beta)8+ T cells . In vivo treatment of mice with SEB leads to an initial increase in the percentage of V(beta)8+ T cells, followed by a decrease in the numbers of these cells, eventually reaching lower levels than those found before treatment with the SAg . This decrease is due to apoptosis of the SEB-responding cells . In the present study, we use the distinct light scattering characteristics of apoptotic cells to characterize T cells that are being deleted in response to SEB in vivo . We show that dying, SEB-reactive T cells express high levels of Fas and Fas ligand (Fas-L), which are implicated in apoptotic cell death . In addition, the B cell marker B220 is upregulated on apoptotic cells . Moreover, we show that the generation of cells with an apoptotic phenotype is severely impaired in response to SEB in functional Fas-L-deficient mutant gld mice, confirming the role of the Fas pathway in SAg mediated peripheral deletion in vivo.

Clin Immunol Immunopathol, 1996 Feb, 78(2), 130 - 9
Preferential activation of CD4+V beta 5.2/5.3+ intestinal intraepithelial lymphocytes in the inflamed lesions of Crohn's disease; Watanabe M et al.; To analyze the nature of intestinal intraepithelial lymphocytes (iIELs) in inflammatory intestinal disease, we established T cell lines of iIELs isolated from endoscopic biopsied ileal and colonic mucosa of Crohn's disease patients . Seven T cell lines from the inflamed terminal ileum of 13 patients, but none of 16 T cell lines from normal terminal ileum, have shown a deviation of T cell receptor variable region gene usage and were enriched in the proportion of CD4+V beta 5.2/5.3+ cells . CD4+V beta 5.2/5.3+ cells in the T cell lines were not increased after stimulation with purified protein derivatives or 65-kDa heat-shock protein but significantly increased after stimulation with staphylococcal enterotoxins C1 and D . Those cells showed increased cytolytic activity against target cells cross-linked by anti-V beta 5.2/5.3 and produced a large amount of interferon-gamma . These results indicated that CD4+V beta 5.2/5.3+ iIELs were preferentially activated in the inflamed lesions of Crohn's disease and may play a possible role in the triggering and progression of human inflammatory intestinal disease.

J Antibiot (Tokyo), 1996 Feb, 49(2), 194 - 8
Carboxamides and hydrazide of glycopeptide antibiotic eremomycin . Synthesis and antibacterial activity; Pavlov AY et al.; Carboxamides and hydrazide of glycopeptide antibiotic eremomycin were obtained by a direct reaction of the carboxy group of eremomycin with an appropriate amine or hydrazine using diphenyl phosphorazidate as a condencing agent . Eremomycin hydrazide was also obtained by hydrazinolysis of the eremomycin methyl ester . Use of dicyclohexylcarbodiimide or 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide for amidation led to the corresponding eremomycin ureides . The ESI-MS data indicate that eremomycin and its amides exist as dimers . The carboxamide, methylamide and benzylamide of eremomycin were as active against Gram-positive bacteria as the parent antibiotic, and the methylamide, benzylamide and hydrazide were almost an order of magnitude more active than eremomycin against Staphylococcus epidermidis clinical isolates in vitro . Amide of eremomycin as well as ureides were devoid of histamine liberating properties, which demonstrates that protection of the carboxyl group leads to a decrease in the allergenic properties.

Eur J Vasc Endovasc Surg, 1996 Feb, 11(2), 148 - 52
Infected false aneurysms of the carotid arteries after carotid endarterectomy; Raptis S et al.; OBJECTIVE: To determine the incidence and management of infected false aneurysms following carotid endarterectomy . DESIGN: Case notes of patients undergoing carotid endarterectomy (CEA) between the years of 1980 and 1993 at two major teaching hospitals, or those patients who represented with complications were reviewed . RESULTS: Eight patients were identified with infected false aneurysms, an incidence of 0.625%, in five CEA had been performed at one of the teaching hospitals, whilst in three other cases the primary operation had been done elsewhere . Presentation was a median 19 days following CEA . In five cases the original arteriotomy was closed by direct suture whilst in three a saphenous vein patch was used . Staphylococcal organisms were cultured in all cases . Antibiotics had not been administered at the original operation . Repair with saphenous vein graft from the common to the internal carotid artery had the least complications . CONCLUSION: Infected false aneurysms are a rare complication following CEA, resection of the false aneurysm and reconstruction with autologous saphenous vein is recommended . Ligation alone is associated with a high incidence of stroke.

Acta Orthop Scand, 1996 Feb, 67(1), 16 - 8
Metallic or absorbable implants for ankle fractures: a comparative study of infections in 3,111 cases; Sinisaari I et al.; Absorbable fracture fixation has been in clinical use since 1984 . Our study compares the infection rates and some infection parameters between metallic (2073 patients) and absorbable fracture fixation devices (1012 patients) in displaced ankle fractures . The infection rate associated with metallic fixation was 4.1%, compared with 3.2% absorbable fixation (p 0.3) . The patients who had a wound infection were older when metallic fixation was used (p 0.01) . They also had a bi- or trimalleolar fracture more often than did patients treated with absorbable fracture fixation, but this difference did not have a significant effect on the wound infection rate (p 0.2) . The infections were mostly caused by microorganisms of the Staphylococcus species . Deep infections were equally common with both fixation methods (0.4%), but there was some variation in the bacterial spectrum.

Cell Immunol, 1996 Feb 1, 167(2), 285 - 92
In vivo analysis of a superantigen-induced T cell suppressor factor; Hu HL et al.; We have previously reported that the superantigen staphylococcal enterotoxin B (SEB) was able to suppress an immune response to sheep red blood cells when administered intravenously to mice . While the capacity of the superantigens to stimulate lymphocytes and accessory cell functions has been thoroughly examined, it is clear that these agents may also exhibit potent immunosuppressive activity both in vivo and in vitro . This SEB-induced immunosuppression was determined by our laboratories to be mediated by a population of T suppressor cells . The suppression may be due to the generation of inhibitory lymphokines, including IL-10 or transforming growth factor beta, following superantigen stimulation . Alternatively, the immunomodulatory activity may be due to the activation of antigen-specific and/or genetically restricted suppressor cells by SEB . The mechanism of activity of these suppressor cells has not been fully defined . In this report we wished to determine whether a suppressor factor generated from SEB-activated T cells in vitro may be responsible for the inhibition of antibody or delayed-type hypersensitivity responses in vivo . We observed that both antibody and delayed-type hypersensitivity responses were inhibited following administration of the SEB-induced suppressor factor . The in vivo inhibitory activity of the SEB-induced suppressor factor was found to be genetically restricted at the "I-J" locus . In addition, monoclonal anti-I-J antibodies recognized the suppressor factor in a haplotype-specific fashion . These results show that the suppressive product of SEB-induced T cells possesses the ability to inhibit, in a genetically restricted fashion, both cellular and humoral immune responses.

Ann Hematol, 1996 Feb, 72(2), 83 - 4
Allogeneic bone marrow transplatation in a patient with Shwachman-Diamond syndrome; Arseniev L et al.; Shwachman-Diamond syndrome (SDS) is a rare inherited disorder involving concomitant neutropenia and exocrine pancreatic insufficiency . About 25% of patients develop hematopoietic malignancies . We describe a 24-year-old male patient with SDS who underwent allogeneic bone marrow transplantation (BMT) because of progression into acute myeloid leukemia (AML) following myelodysplastic syndrome (MDS) . The BMT preparative regimen consisted of busulfan (16 mg/kg body wt.), followed by cyclophosphamide (120 mg/kg) . Cyclosporin A and short methotrexate were used for graft-versus-host disease (GvHD) prophylaxis . The post-transplant period was complicated by staphylococcal septicemia, CMV infection, renal insufficiency, and acute GvHD grade III . Hematological recovery was delayed (post-transplant day +55) . The patient was discharged at day +68 in complete remission without any evidence of MDS . RFLP fingerprint analysis showed complete engraftment of the donor's hematopoiesis . The patient's leukemia relapsed 9 months post-transplant, and death followed due to CMV infection and multiorgan failure . Despite the fatal course in this patient, allogeneic BMT could be an option for curative treatment of the hematopoietic failure in SDS . The interaction of BMT with pancreatic insufficiency still has to be ascertained.

Arch Microbiol, 1996 Feb, 165(2), 73 - 9
Staphylococcal alpha-toxin, streptolysin-O, and Escherichia coli hemolysin: prototypes of pore-forming bacterial cytolysins; Bhakdi S et al.; Staphylococcal alpha-toxin, streptolysin-O, and Escherichia coli hemolysin are well-studied prototypes of pore-forming bacterial cytotoxins . Each is produced as a water-soluble single-chain polypeptide that inserts into target membranes to form aqueous transmembrane pores . This review will compare properties of the three toxin prototypes, highlighting the similarities and also the differences in their structure, mode of binding, mechanism of pore formation, and the responses they elicit in target cells . Pore-forming toxins represent the most potent and versatile weapons with which invading microbes damage the host macroorganism.

Appl Environ Microbiol, 1996 Feb, 62(2), 385 - 92
Engineering of a novel thioether bridge and role of modified residues in the lantibiotic Pep5; Bierbaum G et al.; Pep5 is a 34-amino-acid antimicrobial peptide, produced by Staphylococcus epidermidis 5, that contains the thioether amino acids lanthionine and methyllanthionine, which form three intramolecular ring structures . In addition, two didehydrobutyrines are present in the central part of the lantibiotic and an oxobutyryl residue is located at the N terminus . All rare amino acids are introduced by posttranslational modifications of a ribosomally made precursor peptide . To elucidate the function of the modified residues for the antimicrobial action of Pep5, mutant peptides, in which single modified residues had been eliminated, were produced by site-directed mutagenesis . All of these peptides showed a reduced antimicrobial activity . In addition, those peptides from which the ring structures had been deleted became susceptible to proteolytic digest . This demonstrates that the ring structures serve as stabilizers of conformations essential for activity, e.g., amphiphilicity, as well as for protecting Pep5 against proteases of the producing strains . In addition, residues that could serve as precursors of new modified amino acids in lantibiotics were introduced into the Pep5 precursor peptide . This way, a novel methyllanthionine and a didehydroalanine were inserted into the flexible central part of Pep5, demonstrating that biosynthesis of modified amino acids is feasible by protein engineering and use of the lantibiotic modification system.

J Neurochem, 1996 Feb, 66(2), 644 - 50
Metal selectivity of exocytosis in alpha-toxin-permeabilized bovine chromaffin cells; Tomsig JL et al.; Metal selectivity of exocytosis was analyzed by comparing the effects of polyvalent metal cations Ca2+, Ba2+, Sr2+, Pb2+, La3+, Cd2+, Co2+, Tb3+, Mn2+, and Zn2+ on the release of norepinephrine (NE) from staphylococcal alpha-toxin-permeabilized bovine chromaffin cells . Pb2+, La3+, Cd2+, Sr2+, and Ba2+ activated NE secretion accompanied by the release of intragranular dopamine beta-hydroxylase but not cytosolic lactate dehydrogenase, indicating the activation of the mechanism of exocytosis . The release triggered by saturating concentrations of Pb2+, La3+, Cd2+, and Sr2+ was nonadditive with Ca2+, indicating a common site of action . In contrast, the Ba2(+)-evoked NE release was additive with Ca2+ and the Ca2+ agonists Pb2+, La3+, Cd2+, and Sr2+, suggesting that Ba2+ activates secretion at a site distinct from the Ca2+ receptor . In distinction to the NE release evoked by Pb2+, La3+, Cd2+, and Ba2+, the Sr(2+)-evoked NE release was associated with a significant elevation of Ca2+ concentration in the medium and abolished by Ca2+ chelation . This indicates that the secretagogue effect of Sr2+ was indirect and secondary to the displacement of bound Ca2+, Co2+ and Mn2+ inhibited the NE release evoked by Ca2+, Sr2+, Pb2+, La3+, and Cd2+ but had no effect on the Ba(2+)-dependent secretion . Tb3+ and Zn2+ were without effect on exocytosis.

Toxicology, 1996 Jan 22, 107(1), 69 - 81
Protective effects of niacinamide in staphylococcal enterotoxin-B-induced toxicity; LeClaire RD et al.; Staphylococcal enterotoxins (SE) interact with major histocompatibility complex (MHC) class II cell-surface receptors, eliciting signal transduction in antigen-presenting cells (APC) . Subsequent toxin-class II complex interaction with specific T-cell receptors induces T-cell activation . We investigated the effect of niacinamide and interleukin (IL)-10 on SEB-induced responses . In a macrophage cell line, niacinamide (ED50--2mM) and IL-10 (ED50--7U/ml) inhibited interferon (IFN)-gamma-induced MHC class II expression in a dose-dependent manner . Also, niacinamide was a potent inhibitor of T-cell proliferation induced by SEB (ED50-- 1 mM) while IL-10 has minimal effects . In mice, the temporal responses of IL-1alpha, tumor necrosis factor (TNF)-alpha, IL-2, and IFN-gamma evoked by SEB were synergistically potentiated by lipopolysaccharide (LPS) . Lethality occurred only when SEB was potentiated by LPS . Niacinamide or IL-10 improved survival of mice after lethal SEB challenge . Niacinamide reduced cytokine serum levels, although the pattern differed from that of IL-10 . Niacinamide primarily reduced IL-2 and IFN-gamma, while IL-10 predominantly reduced IL-1alpha and TNF-alpha . The immunomodulatory effects of niacinamide observed on SEB-induced activation of APC and T-cells in vitro and in the LPS potentiated murine model for SEB-induced toxicity suggest it may have therapeutic value.

Ned Tijdschr Geneeskd, 1996 Jan 20, 140(3), 138 - 41
{Methicillin-resistant Staphylococcus epidermidis}; Vandenbroucke-Grauls CM; Staphylococcus epidermidis has long been overlooked as a pathogen . Modern medicine gives this bacterium ample opportunities to display its pathogenic properties, notably as a colonizer of medical devices (catheters, implants), on which it grows, protected by an exopolysaccharide ('slime') layer . In addition, more and more methicillin-resistant strains are isolated . In Dutch intensive care units S . epidermidis is responsible for 20% of all infections, approximately one third of these isolates are methicillin resistant . As most people have S . epidermidis on their skin, spread and cross infection are unavoidable; still a judicious antibiotic use help to keep the frequency of resistance as low as possible.

J Immunol, 1996 Jan 15, 156(2), 523 - 32
Selective activation-induced apoptosis of peripheral T cells imposed by macrophages . A potential mechanism of antigen-specific peripheral lymphocyte deletion; Munn DH et al.; The self-reactive T cells that escape clonal deletion in the thymus must be suppressed by the less well characterized process of peripheral tolerance . In this study, we show that monocyte-derived macrophages (M phi) undergoing terminal differentiation in the presence of macrophage CSF (M-CSF) acquire the ability to selectively induce apoptosis of T cells in an activation-specific fashion . Lymphocytes were stimulated via the TCR using anti-CD3 cross-linking, staphylococcal superantigen, or allogeneic mixed-leukocyte cultures . T cells activated while in contact with M-CSF-derived M phi exited the resting G0 state and re-entered the cell cycle, but experienced a sustained arrest near the first G1/S transition, followed by progressive apoptosis . In contrast, lymphocytes that were not stimulated remained viable, and could later activate normally when removed from contact with M phi . Functionally, exposure of T cells to alloantigens presented by M-CSF-derived M phi resulted in a selective depletion of the alloresponsive T cell population, while preserving reactivity to other mitogens and to alloantigens from different donors . The ability of M phi to impose activation-induced apoptosis on lymphocytes was regulated developmentally, being absent in fresh monocytes, progressively acquired during differentiation in M-CSF, and abrogated if monocytes were exposed to IFN-gamma before differentiation . We speculate that this novel interaction may help to selectively delete autoreactive T cells that respond to self Ags presented by noninflammatory tissue M phi.

J Mol Biol, 1996 Jan 12, 255(1), 215 - 28
Further evidence on the equilibrium "pre-molten globule state": four-state guanidinium chloride-induced unfolding of carbonic anhydrase B at low temperature; Uversky VN et al.; Equilibrium guanidinium chloride-induced unfolding of bovine carbonic anhydrase NB has been investigated by a combination of optical methods with size-exclusion chromatography . It has been shown that, as in the case of staphylococcal beta-lactamase, bovine carbonic anhydrase B unfolds at low temperature through two equilibrium intermediates; the molten globule and the pre-molten globule states . This pre-molten globule state has a hydrodynamic volume no more than twofold larger than that of the native state, i.e . is relatively compact . It has a pronounced far UV CD spectrum, suggesting the presence of a substantial secondary structure . It binds 8-anilinonaphthalene-1-sulphonate (though weaker than the molten globule state), which suggests the formation of solvent-exposed clusters of non-polar groups . Thus, this novel state of protein molecules shares a number of properties with the "burst" kinetic intermediate of protein folding and can be considered as its equilibrium counterpart.

Biochemistry, 1996 Jan 9, 35(1), 22 - 31
The mechanism of binding staphylococcal protein A to immunoglobin G does not involve helix unwinding; Jendeberg L et al.; Structural changes in staphylococcal protein A (SpA) upon its binding to the constant region (Fc) of immunoglobulin G (IgG) have been studied by nuclear magnetic resonance and circular dichroism (CD) spectroscopy . The NMR solution structure of the engineered IgG-binding domain of SpA, the Z domain (an analogue of the B domain of SpA), has been determined by simulated annealing with molecular dynamics, using 599 distance and dihedral angle constraints . Domain Z contains three alpha-helices in the polypeptide segments Lys7 to His18 (helix 1), Glu25 to Asp36 (helix 2), and Ser41 to Ala54 (helix 3) . The overall chain fold is an antiparallel three-helical bundle . This is in contrast to the previously determined X-ray structure of the similar SpA domain B in complex with Fc, where helix 3 is not observed in the electron density map {Deisenhofer, J . (1981) Biochemistry 20, 2361-2370}, but similar to the solution NMR structure of domain B, which is also a three-helical bundle structure {Gouda, H., et al . (1992) Biochemistry 31, 9665-9672} . In order to characterize possible secondary structural changes associated with IgG binding, far-UV CD spectra were collected for the Z domain, an engineered repeat of this molecule (ZZ), recombinant Fc from IgG subclass 1 (Fc1), recombinant Fc from IgG subclass 3 (Fc3), and mixtures of Z/Fc1, Z/Fc3, ZZ/Fc1, and ZZ/Fc3 . Fc3 was included as a control for possible changes of the CD spectrum in the mixture of noncomplexed molecules, since SpA is known not to bind Fc3 . From these CD spectra, it was concluded that the third alpha-helix in Z is not disrupted in its complexes with Fc1 . Similar results were obtained for the ZZ molecule . However, in both Z and ZZ there are some perturbations in CD spectra at high energy wavelengths (i.e., lambda < 215 nm) accompanying complex formation . On the basis of the combined CD and NMR results, as well as previously described binding studies of Z mutant proteins to Fc1, we conclude that the Z domain maintains its three-helical bundle structure in the Z-Fc complex, though there may be a small structural change involved in the binding mechanism.

Srp Arh Celok Lek, 1996, 124 Suppl 1, 151 - 3
{Treatment of peritonitis in patients on chronic peritoneal dialysis with a single dose of vancomycin}; Radovanovic Lj; One dose vancomycinum was successful in treatment of peritonitis in patients undergoing chronic peritoneal dialysis if it was used after initial signs of disease immediately . Thirteen episodes of peritonitis treated in that manner were analysed . Microorganisms isolated previously were: Staphylococcus epidermidis in seven . Enterococcus in three, while no organisms were isolated in three cases . Vancomycinum was applied at the same time intravenously 0.5 g and intraperitoneally 0.5 g in the peritoneal solution for the six to eighteen hours . The treatment was successful in ten and failed in three cases with other medical complications: the tunnel infection in two and Tenckhoff catheter obstruction in one patient . The advantage of such treatment is in healing of most patients, it is cheap, the small drug dose diminishes its toxic effects and the duration of the hospital care is only one day . Anyway, it is not recommended in the treatment of patients with catheter obstruction, tunnel infection and other complications.

Acta Otolaryngol Suppl, 1996, 523, 90 - 3
Role of gamma delta-T cells in the palatine tonsil; Yamanaka N et al.; Gamma delta-T cells in the tonsil were evaluated by flow cytometric analysis and immunohistological study using monoclonal antibodies to the gamma delta-T cell receptor . Flow cytometric analysis using TCR-gamma/delta-1 showed that 2.2%, of T cells in the tonsil obtained from patients with recurrent or chronic tonsillitis expressed the gamma delta-T cell receptor . Immunohistologically, gamma delta-T cells were found mainly in the extrafollicular area, i.e., the T-cell zone, and showed strong migration to the crypt epithelium in tonsils with infections . The comparison on number of gamma delta-T cells in cases with simple hypertrophic tonsil and in cases with recurrent or chronic tonsillitis showed that tonsils with repeated or chronic infections had a significantly greater number of gamma delta-T cells than tonsils without infection . To address the functional aspects of gamma delta-T cells in the tonsil, the production of IL-2 of separated gamma delta-T cells was measured by solid phase ELISA . Increased IL-2 production was observed with staphylococcal enterotoxin A and B stimulation, and this increase was blocked by antibody to the gamma delta-T cell receptor, indicating that the production of IL-2 may be triggered by the interaction between the gamma delta-T cell receptor and staphylococcal enterotoxin . Our results show that gamma delta-T cells in the tonsil, especially in the crypt epithelium, may be activated by various bacterial antigens or heat shock protein released from damaged epithelial cells . The activated gamma delta-T cells will produce cytokines including IL-2 and function as so-called 'first-layer' immunity.

Acta Otolaryngol Suppl, 1996, 523, 197 - 200
Antibody production to heat shock proteins with Mr 65 kD (HSP65) in cutaneous inflammation: a possible relation to focal infection; Izaki S et al.; In order to correlate the immunomodulatory roles of homologous heat shock proteins with Mr 65 kD (HSP65) to skin diseases, antibody level to recombinant-HSP65 of Mycobacterium leprae was quantified with enzyme-linked immunosorbent assay (ELISA) in the sera of patients . In psoriasis, an insignificant increase was observed in anti-HSP65 IgG (0.111 +/- 0.053, mean +/- SD in 0D492 nm, n = 22), compared with a normal group (0.080 +/- 0.032, n = 9) . However, psoriasis of acute guttate-type (PGA), which is often induced after tonsillar infection, showed a significant increase (0.178 +/- 0.032 n = 4, p <0.001), but psoriasis vulgaris did not (PV) (0.101 +/- 0.053, n = 12), nor generalized psoriasis pustulosa (PP) (0.087 +/- 0.025, n = 6) . Similarly, patients with palmoplantar pustulosis (PPP) with tonsillar or periodontal infection showed significantly high anti-H5P65 IgG (0.230 +/- 0.065, n = 7, p <0.0001), compared with only a mild increase in PPP without suspected infectious foci (0.139 +/- 0.066, n = 13, p <0.05) . Possible staphylococcal infection in the oral cavity was suggested by an additional ELISA assay to staphylococcal antigen: anti-staphylokinase IgG showed a significant increase in PPP with infectious foci (0.110 +/- 0.028 n = 3, p <0.01) compared with the normal group (0.039 +/- 0.014), while PPP without them showed only a mild change (0.060 +/- 0.017, n = 6, p <0.05) . We assume that immunoreaction to H5P65 may be involved in psoriatic skin inflammation associated with focal infection.

Acta Med Austriaca, 1996, 23(5), 164 - 7
{Infectious complications of cardioverter/defibrillators--case report and review of the literature}; Hollenstein U et al.; Implantable cardioverters/defibrillators have greatly improved survival in patients with malignant ventricular arrhythmias . As modern devices and technical skill and experience reduce surgical complications attention is focussed on the potentially lethal infections of these devices . Staphylococcus spp . can be isolated as the predominant causative organisms . Devices that require thoracotomy (as opposed to transvene systems) and generator replacement (as opposed to primary implantation) carry a higher risk of infections . Although there are sporadic reports on successful conservative management of ICD infection, explantation of the generator, leads and patches followed by reimplantation of a new device after no less than 2 weeks is still the recommended procedure . Concomitant intravenous antibiotic therapy should be continued for 4 to 6 weeks.

Protein Eng, 1996 Jan, 9(1), 5 - 14
Does a backwardly read protein sequence have a unique native state?
Olszewski KA, Kolinski A, Skolnick J.
Amino acid sequences of native proteins are generally not palindromic . Nevertheless, the protein molecule obtained as a result of reading the sequence backwards, i.e . a retro-protein, obviously has the same amino acid composition and the same hydrophobicity profile as the native sequence . The important questions which arise in the context of retro-proteins are: does a retro-protein fold to a well defined native-like structure as natural proteins do and, if the answer is positive, does a retro-protein fold to a structure similar to the native conformation of the original protein? In this work, the fold of retro-protein A, originated from the retro-sequence of the B domain of Staphylococcal protein A, was studied . As a result of lattice model simulations, it is conjectured that the retro-protein A also forms a three-helix bundle structure in solution . It is also predicted that the topology of the retro-protein A three-helix bundle is that of the native protein A, rather than that corresponding to the mirror image of native protein A . Secondary structure elements in the retro-protein do not exactly match their counterparts in the original protein structure; however, the amino acid side chain contract pattern of the hydrophobic core is partly conserved.

J Cataract Refract Surg, 1996, 22 Suppl 2, 1331 - 5
In vitro bacterial adherence to hydrogel and poly(methyl methacrylate) intraocular lenses; Ng EW et al.; PURPOSE: To compare the in vitro adherence of Staphylococcus epidermidis to poly-(hydroxyethyl methacrylate) (polyHEMA) or hydrogel intraocular lenses (IOLs) and poly(methyl methacrylate) (PMMA) IOLs . SETTING: Lions Eye Institute, Perth, Western Australia . METHODS: One-piece hydrogel lenses and one-piece PMMA lenses were suspended for 60 minutes in standardized suspensions of a well-characterized strain of S . epidermidis and then sonicated in a known quantity of balanced salt solution to remove the adherent bacteria . Quantitative cultures of the sonicates were performed and the results analyzed statistically . RESULTS: The mean bacterial adherence of S . epidermidis to the PMMA IOLs (58,400 CFU) was more than 20 times greater than that to the hydrogel IOLs (1953 CFU) . The difference was statistically significant (P < .001) . CONCLUSIONS: Adherence of S . epidermidis to hydrogel IOLs is significantly lower than to PMMA IOLs . This suggests that the risk of postoperative endophthalmitis after cataract extraction and IOL implantation may be lower with the use of hydrogel IOLs.

Antibiot Khimioter, 1996, 41(10), 28 - 9
{Effectiveness of the treatment of staphylococcal pneumonia with liposomal gentamicin in an experiment}; Perepelkin AI et al.; An in vivo comparative study on penetration of free gentamicin sulfate and liposome-entrapped gentamicin sulfate to macrophages was performed and the efficacy of the treatment of destructive pneumonia was estimated on albino mice . The liposome-entrapped antibiotic was arrested by the cells of the mononuclear phagocytic system thus providing higher concentrations of the drug in the organs with high counts of macrophages, the antibiotic retention time in the organs being longer than that after the use of free gentamicin . The use of liposome-entrapped gentamicin in the treatment of destructive pneumonia made it possible to increase the host protection from 17 to 50 per cent.

Bull Soc Belge Ophtalmol, 1996, 260, 73 - 7
{Surgery for glaucoma and endophthalmitis}; Collignon-Brach J; The incidence of endophthalmitis after glaucoma surgery appears to be related to surgical procedures . After trabeculectomy the incidence is low from 0.06% to 0.2% but trabeculectomy with adjunctive antimetabolites increases the risk to 3% or more . Early onset endophthalmitis is due to the penetration of germs from patient's own external flora during the surgery, especially staphylococcus epidermidis.

Autoimmunity, 1996, 24(3), 187 - 97
Fusidic acid and insulin-dependent diabetes mellitus; Nicoletti F et al.; Insulin-dependent diabetes mellitus (IDDM) is a major cause of morbidity and mortality from long-standing complications . The autoimmune nature of IDDM has encouraged use of immunosuppressive and antiinflammatory strategies to better preserve residual pancreatic beta-cell function at the time of diagnosis . Fusidic acid and its sodium salt, fusidin, is a relatively atoxic antibiotic used mainly in the treatment of staphylococcal infections . Recently, fusidin has been demonstrated to possess immunosuppressive functions in vitro and in vivo, and the drug has shown promise in preventing the disease in animal models of IDDM and in a preliminary trial in IDDM patients.

Vopr Med Khim, 1996 Jan-Mar, 42(1), 39 - 45
{Immunoenzyme assay of staphylococcal toxin using polyamide micropore membranes}; Tashmukhamedova ShS et al.; The optimum conditions for extraction of catalytic active conjugates of alpha-amylase and antibodies for staphylococcal toxin (ST) have been created . The optimum correlation of antibodies and enzyme for the effective use of the extracted conjugate during enzyme immunoassay for ST has been established . The covalent immobilization of antibodies on the micropore polyamide membranes has been carried out . Apart from this, the extracted conjugated were purified by TSK-gel HN-55 chromatography . The optimum concentration of the conjugates has been defined.

Transpl Int, 1996, 9 Suppl 1, S155 - 6
The importance of late infections for the long-term outcome after liver transplantation; Raakow R et al.; We investigated the late infections of 400 consecutive liver transplantations performed in 368 patients . After a mean follow-up of 45 months, a total of 180 late infections occurred in 110 liver recipients . Frequent agents were CMV, enterococcus, candida and staphylococcus . Pneumonia was the most dangerous late infection with a high mortality rate . Late infections were responsible for ten deaths that were all caused by atypical pneumonia . The majority of late infections appeared during the first year after liver transplantation . Thereafter, the risk of infection declined significantly.

Clin Rheumatol, 1996 Jan, 15(1), 59 - 61
Reactive arthritis by staphylococcus epidermidis: report of an unusual case; Giordano N et al.; In the literature many cases of Staphylococcus epidermidis (SE) complications are reported, but we have not found any reference about reactive arthritis secondary to SE . We report an unusual case of a patient with SE bacteriaemia, who developed elbow arthritis, asymmetrical sacroiliitis, keratoderma and restrictive cardiomyopathy . The clinical pictures, the instrumental and biochemical findings, in particular the positivity of HLA B27, allow us to set this case in the complex and heterogeneous chapter of reactive arthritis.

Med Dosw Mikrobiol, 1996, 48(1-2), 55 - 9
{Bacterial flora of acne lesions in diagnostic material of the Microbiology and Immunology Department, Pomeranian Medical Academy (PAM) in Szczecin}; Zaluga E et al.; A retrospective analysis of the bacterial flora of acne lesions was carried out in 320 patients . Atypical flora was isolated very rarely . The pathogenic flora was found most frequently in the Autovaccine Laboratory when the microbiological material was taken directly onto plates and the investigation was repeated several times . Atypical flora was isolated only from three cases . Propionibacterium and Staphylococcus epidermidis were found to be sensitive to the antibiotics routinely used in the treatment of acne . The highest antibacterial effect in vitro against both these species was demonstrated using rifampicin and tetracycline.

Arch Immunol Ther Exp (Warsz), 1996, 44(2-3), 131 - 6
Mouse multivalent IgG(2a, b) antibody--ricin A-chain immunotoxins combined with homologous or heterologous interleukin 2 in the treatment of a murine malignant lymphoproliferation (EL4); Mota G et al.; Two immunotoxins containing ricin A-chain, staphylococcal protein A and mouse anti-Thy 1.2 antibodies of IgG(2a,b) subclass, were prepared . The two multivalent immunotoxins of 750 and 370 kDa and molar ratio A-chain: IgG of 1:2, were used for the treatment of mice bearing ascitic EL4 lymphoma . The immunotoxin-treatment, performed intraperitoneally, was combined or not with homologous or heterologous interleukin 2 . The antitumor effects expressed by increase of mice survival time (p < 0.001 as compared with nontreated animals) corresponded to a proportion of 88-90% lymphoma cell-kill by immunotoxin and 93-95% by combination treatment (immunotoxin + interleukin 2), as calculated from the relationship between the survival time of nontreated mice and the number of tumor cells inoculated.

Microbios, 1996, 86(349), 247 - 53
A mouse model for staphylococcal enterotoxins toxicity; Bhatti AR et al.; The study of staphylococcal enterotoxins (SE), which can adversely affect man and animals, is hindered by the absence of a practical animal model . Only humans and primates are sensitive to SE oral intake whereas other species such as cats and dogs require intravenous SE administration to induce biological effects . Rodents are very resistant even to relatively high doses of SE . Treatment of mice with D-galactosamine (20 mg/mouse) rendered them highly susceptible to micrograms of toxins leading to lethal shock . Differences in toxic potential have been observed between types of SE . Carboximethylated SE, which have been shown not to induce emesis in primates were also able to induce shock . Anti-tumour necrosis factor antiserum (anti-TNF-alpha) and, to a lesser extent anti-SE antisera, reduced the lethality to SE in D-galactosamine-treated mice . This proposed cost-effective animal model may be used to study the immunopathological properties of natural, recombinant or mutant SE.

Scand J Infect Dis, 1996, 28(4), 415 - 6
Development of listeriosis during vancomycin therapy in a neutropenic patient; Arsene O et al.; Vancomycin and aminoglycosides are widely used for fever in neutropenic patients . This combination of antibiotics has also been proposed for the treatment of Listeria monocytogenes bacteremia . We report a case of fatal listeriosis in a 33-year-old man during acute lymphoblastic leukemia induction therapy in a total protective environment despite him having been on vancomycin for 8 days for treatment of staphylococcus bacteremia . Vancomycin and aminoglycoside cannot be proposed for the treatment of L . monocytogenes bacteria in neutropenic patients . Neutropenia might be a risk factor for listeriosis in cancer patients.

Hematopathol Mol Hematol, 1996, 10(3), 123 - 33
Acquired type 2A von Willebrand disease in chronic myelocytic leukemia; Mohri H et al.; Acquired von Willebrand disease (vWD) has been described in a few patients with chronic myelocytic leukemia (CML) . We present here acquired type 2 vWD associated with CML and provide characterization of an inhibitor to von Willebrand factor (vWF) from this patient . His bleeding time was prolonged . Ristocetin-induced platelet agglutination was abolished whereas botrocetin-mediated aggregation was normal . Multimeric analysis of vWF from patient's plasma showed that larger sizes of multimers were reduced . His past and family histories were negative for bleeding tendency . These results suggested that acquired type 2 vWD was present during his clinical course . The inhibitor was purified by Staphylococcal protein A, suggesting an IgG antibody . Both binding of 125I-vWF to GPIb and platelet agglutination by ristocetin were inhibited by the patient IgG with the concentrations of competing substances necessary to inhibit specific binding by 50% (IC50s) of 260 micrograms/ml and 420 micrograms/ml, respectively . However, the IgG had no effect on these studies mediated by botrocetin . The IgG only reacted with intact vWF and a 39/34 kDa fragment of vWF . These results indicate that the recognition of GPIb binding site(s) on vWF by the IgG is a central pathogenesis of acquired type 2 vWD in this case.

Int Orthop, 1996, 20(4), 222 - 6
Bipolar hip replacement in sickle cell disease; Sanjay BK et al.; A retrospective study is presented of 26 uncemented bipolar hip replacements for avascular necrosis of the femoral head due to sickle cell disease which were carried out between 1987 and 1992 . All patients were treated according to a protocol . The average follow up was 4.6 years (range 2.1 to 7 years) . After operation, the average Harris hip score improved from 36 to 88 . Bone culture was positive for bacterial growth in 4 hips (coagulase negative staphylococcus in 3) . There was progressive wear of acetabular articular cartilage in 2 cases, but no clinical or radiological evidence of loosening of the femoral stem . Seventeen complications occurred in 9 of the 21 patients (5 in one patient) . A longitudinal split of the femur was the commonest operative complication and occurred in 5 hips . Femoral medullary sclerosis was seen in 8 cases . Patients with sickle cell disease have a high risk of complications, but this type of hip replacement should be considered in carefully selected patients who have avascular necrosis of the femoral head.

Acta Neurochir (Wien), 1996, 138(7), 829 - 34
Shunt malfunction in relation to shunt infection; Vanaclocha V et al.; Ventriculo-peritoneal shunt malfunction may be caused by shunt infection which may not be clinically apparent as the cause of the malfunction by standard diagnostic criteria . This suggests that the real incidence of infected shunts might be higher than previously suspected . In order to study the relationship between infection and shunt malfunction, we followed a protocol over five years (54 V-P shunts) consisting of (1) removal of the malfunctioning shunt and replacement in the same surgical procedure with a new one or institution of an external ventricular drainage for 8 days (if there were clear signs of infection), (2) culturing of CSF and every part of the removed shunt, and (3) intravenous antibiotic treatment (Vancomycin 1g./12h + Ceftriaxone 1g./12h) for five days after the new V-P shunt had been inserted . In those cases in which an external ventricular drainage had been placed, its tip and a portion of the new V-P shunt were also cultured . The results showed that although CSF cultures were negative in 49/54 cases (90.7%), cultures of the removed shunts were positive in 32/54 (59.2%), most of them (21/32, 65.6%) for Staphylococcus coagulase negative organisms . The CSF samples obtained by puncturing the reservoir on admission to Hospital were positive only in 5 out of 54 cases (9.2%), only in those showing clinical features of infection . In the remaining cases, 27 out of 54 (50%) the CSF cultures were negative but the shunt cultures proved positive and required further treatment . For the newly inserted shunts (173) CSF was collected through the shunt during the surgical procedure, and a small piece of the extra-tube from the ventricular and from the peritoneal catheter were obtained and cultured . All the six shunts (6/173, 3.4%) that showed positive cultures after insertion had to be replaced within a period of three to four weeks due to malfunction (range 26 +/- 7 days), indicating that the systematic culture of CSF and tubing helps to predict which shunts will soon need to be replaced due to infection . We conclude that CSF culture alone does not rule out infection in cases of shunt malfunction . The percutaneous CSF obtained from the shunt reservoir admission is particularly prone to show negative cultures even when the shunt is colonized by bacteria.

J Dermatol Sci, 1996 Jan, 11(1), 28 - 35
Suppressive effect of staphylococcal enterotoxin B on murine contact hypersensitivity; Abe K et al.; Superantigens (SAg) possess the capacity to interact with particular V beta regions of T cell receptor (TCR) and major histocompatibility complex (MHC) class II molecules, and activate a large number of T cells and accessory cells . staphylococcal enterotoxins (SEs) are recently well known as SAg and anticipate to modulate immunological reactions . In this study, we investigated the effect of staphylococcal enterotoxin B (SEB) on contact hypersensitivity reaction (CHR) to 2,4-dinitrofluorobenzene (DNFB) in BALB/c mice . SEB-injection inhibited the induction of sensitization on CHR . Suppressor cells were not found in the spleen or lymph node cells from mice treated with SEB . Normal spleen cells cultured with SEB showed significant proliferation and tumor necrosis factor-alpha (TNF-alpha) production . CHR was suppressed by intravenous injection of the culture supernatant . In addition, anti-TNF-alpha antibodies inhibited the suppressive effect induced by the supernatant . These findings indicate that TNF-alpha produced by SEB-responding cells inhibits the induction of sensitization on CHR . Therefore, SAg may play important roles in the modulation of immune system through the stimulation of TNF-alpha production.

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