Mol Immunol, 1997 Apr, 34(6), 493 - 503 Affinity and kinetics of the interactions between an alphabeta T-cell receptor and its superantigen and class II-MHC/peptide ligands; Khandekar SS et al.; Immune activation is mediated by a specific interaction between the T-cell receptor (TCR) and an antigenic peptide bound to the major histocompatibility complex (MHC) . T-cell activation can also be stimulated by superantigens which bind to germline-encoded variable domain sequences of certain TCR beta-chains . We have used a surface plasmon resonance biosensor to characterize the molecular interactions between a class II-restricted alphabeta TCR and its superantigen and MHC/peptide ligands . The extracellular domains of the murine D10 TCR (Valpha2, Vbeta8.2) were expressed in insect cells and secreted as a disulfide-linked heterodimer . In the absence of MHC class II, purified soluble D10 TCR bound to Staphylococcus aureus enterotoxin C2 with an association rate of 1.69+/-0.12 x 10(4)M(-1) sec(-1) and a dissociation rate of 1.9+/-0.47 x 10(-2) sec(-1), giving a dissociation constant of 1.1 microM . Binding of the TCR to S . aureus enterotoxin B was barely detectable and could not be measured accurately due to the rapid dissociation rate . Soluble D10 TCR also bound to a soluble murine MHC class II I-A(k) molecule containing a fused antigenic conalbumin peptide and complementary leucine zipper sequences to facilitate efficient chain pairing . The purified I A(k) chimera specifically stimulated proliferation of the D10 T-cell clone, and bound to immobilized soluble D10 TCR with an association rate of 1.07+/-0.19 x 10(4)M(-1)sec(-1) and a dissociation rate of 2.2+/-0.65 x 10(-2) sec(-1), giving a dissociation constant of 2.1 microM. Biochem J, 1997 Sep 15, 326 ( Pt 3), 837 - 46 Evidence that human class Theta glutathione S-transferase T1-1 can catalyse the activation of dichloromethane, a liver and lung carcinogen in the mouse . Comparison of the tissue distribution of GST T1-1 with that of classes Alpha, Mu and Pi GST in human; Sherratt PJ et al.; The cDNA encoding human glutathione S-transferase (GST) T1 has been expressed as two recombinant forms in Escherichia coli that could be purified by affinity chromatography on either IgG-Sepharose or nickel-agarose; one form of the transferase was synthesized from the pALP 1 expression vector as a Staphylococcus aureus protein A fusion, whereas the other form was synthesized from the pET-20b expression vector as a C-terminal polyhistidine-tagged recombinant . The yields of the two purified recombinant proteins from E . coli cultures were approx . 15 mg/l for the protein A fusion and 25 mg/l for the C-terminal polyhistidine-tagged GST T1-1 . The purified recombinant proteins were catalytically active, although the protein A fusion was typically only 5-30% as active as the histidine-tagged GST . Both recombinant forms could catalyse the conjugation of glutathione with the model substrates 1,2-epoxy-3-(4'-nitrophenoxy)propane,4-nitrobenzyl chloride and 4-nitrophenethyl bromide but were inactive towards 1-chloro-2,4-dinitrobenzene, ethacrynic acid and 1-menaphthyl sulphate . Recombinant human GST T1-1 was found to exhibit glutathione peroxidase activity and could catalyse the reduction of cumene hydroperoxide . In addition, recombinant human GST T1-1 was found to conjugate glutathione with dichloromethane, a pulmonary and hepatic carcinogen in the mouse . Immunoblotting with antibodies raised against different transferase isoenzymes showed that GST T1-1 is expressed in a large number of human organs in a tissue-specific fashion that differs from the pattern of expression of classes Alpha, Mu and Pi GST . Most significantly, GST T1-1 was found in only low levels in human pulmonary soluble extract of cells, suggesting that in man the lung has little capacity to activate the volatile dichloromethane. Ann Rheum Dis, 1997 Aug, 56(8), 470 - 5 Incidence and sources of native and prosthetic joint infection: a community based prospective survey; Kaandorp CJ et al.; OBJECTIVES: To determine the incidence and sources of bacterial arthritis in the Amsterdam health district and the maximum percentage of cases that theoretically would be preventable . METHODS: Patients with bacterial arthritis diagnosed between 1 October 1990 and 1 October 1993 were prospectively reported to the study centre by all 12 hospitals serving the district . Data were gathered on previous health status, source of infection, and microorganisms involved . RESULTS: 188 episodes of bacterial arthritis were found in 186 patients . Most of the 38 children were previously healthy . Fifty per cent of the adults were 65 years or older . Of the adults 84% had an underlying disease, in 59% a joint disorder . Joint surgery constituted the largest part of direct infections (33%) and skin defects were the most important source of haematogenous infections (67%) . Infection of joints containing prosthetic or osteosynthetic material by a known haematogenous source occurred 15 times (8%) . Staphylococcus aureus was the causative organism in 44% of all positive cultures . CONCLUSION: The incidence of bacterial arthritis was 5.7 per 100,000 inhabitants per year . Preventive measures directed to patients with prosthetic joints or osteosynthetic material, and a known haematogenous source would have prevented at most 8% of all cases. Gene, 1997 Sep 1, 196(1-2), 249 - 59 Prevalence and chromosomal map location of Staphylococcus aureus adhesin genes; Smeltzer MS et al.; Using genomic DNA from 25 unrelated strains and probes specific for each gene, we assessed the prevalence of the Staphylococcus aureus (Sa) adhesion genes cna, fnbA, fnbB, fib, clfA, fbpA, ebpS and map . All 25 strains encoded fib, clfA, ebpS, map and at least one of the fnb genes . fbpA and coa appeared to be allelic variants of the same gene with the fbpA variant being present in only four of 25 isolates . cna was present in 10 of 25 strains . Using Southern blot analysis of SmaI-digested genomic DNA resolved by pulsed-field gel electrophoresis, the adhesion genes were mapped to SmaI fragments A (ebpS), B (fib and clfA), C (fnbA/fnbB), E (fbpA), F (map) and G (cna) . Despite variations in SmaI restriction profiles, co-localization of adhesin genes with genes known to map to specific SmaI fragments in the Sa 8325-4 chromosome strains suggests that the chromosomal location of each adhesin gene is conserved. Gene, 1997 Sep 1, 196(1-2), 239 - 48 The Staphylococcus aureus collagen adhesin-encoding gene (cna) is within a discrete genetic element; Gillaspy AF et al.; Although the gene (cna) encoding the Staphylococcus aureus (Sa) collagen adhesin is not present in all strains, the DNA both upstream and downstream of cna is present in all Sa strains . Using oligo primers corresponding to the conserved nt flanking cna and template DNA from Sa strains that do not encode cna, we amplified a 372-bp fragment . These results illustrate that the conserved regions upstream and downstream of cna are contiguous in strains that do not encode cna . Using primers corresponding to the conserved flanking DNA together with primers corresponding to the 5' and 3' ends of cna, we also amplified DNA fragments containing the junctions between the cna genetic element and the conserved flanking sequences . Sequence comparisons of the amplification products from four cna negative and four cna positive strains revealed that cna is within a discrete genetic element that extends 202 bp upstream from the cna start codon and 100 bp downstream of the cna stop codon . Sequence analysis of the ends of the cna element did not reveal any of the repeats characteristic of transposable elements . These results suggest that cna may be part of a larger element (e.g., a phage) that may or may not contain cna . Alternatively, cna may be a subject to a precise excision event resulting in its deletion from the chromosome . Based on sequence analysis of the flanking DNA amplified from strains that do not encode cna, the presence of a cna genetic element does not disrupt an ORF. Leuk Lymphoma, 1997 Jul, 26(3-4), 377 - 85 Coexistence of life threatening chemotherapy related leukoencephalopathy, saggital sinus thrombosis and multiple organ failure in a child with acute lymphoblastic leukemia: an unusual case with clinical recovery; Duru F et al.; A nine-year old girl with T cell acute lymphoblastic leukemia (ALL) had acute severe neurologic complications at the end of the remission-induction chemotherapy course . Thirty-six hours following triple intrathecal (IT) therapy and intravenous (IV) administration of L-asparaginase (L-asp), tetraplegia developed and she became unconscious . She had bouts of hypertension and persistent tachycardia unresponsive to digitalis therapy . Magnetic resonance imaging (MRI) showed multiple brain white matter hyperintensities and filling defects in the saggital sinus, suggesting thrombosis . Over the 40 days, in addition to her neurologic compromise she also had transient diabetes mellitus, severe hyperlipidemia, hypoproteinemia and edema, liver and heart failure and staphylococcus aureus sepsis with prolonged bone marrow depression . Despite, coexistence of all these chemotherapy related complications, her neurologic functions and multiple organ failure improved gradually . After a 70 days' period of interruption, chemotherapy was resumed and continued without any further complications . Although, the etiology of her extensive sensitivity to some drugs remains unclear, we believe that it is important to document these unusual events in this child. Aust N Z J Surg, 1997 Oct, 67(10), 682 - 5 The epidemiology of methicillin-resistant Staphylococcus aureus: surgical relevance 20 years on; McDonald M; Despite vigorous attempts at eradication over the last 20 years, methicillin-resistant Staphylococcus aureus (MRSA) continues to be a major nosocomial pathogen in Australian acute care institutions . The epidemiology of hospital spread is now well characterized; infected and colonized patients provide the primary reservoirs, and transmission is mainly via hospital staff . The MRSA remains endemic in most of Australia's large urban teaching hospitals; occasional outbreak also occur, especially in intensive care areas . The level of MRSA infection is often indicative of the total rate of nosocomial infection within an institution and may reflect overcrowding, heavy workloads and under-staffing of wards . Standard precautions, isolation and cohorting of infected and colonized patients, screening of staff, hand washing campaigns, nasal eradication policies and increased staff education have all been tried, with variable success . There is no universal formula; local problems require local solutions plus commitment of local resources . Preventing surgical infection with MRSA requires the application of surgical first principles, and the routine use of vancomycin for prophylaxis is not recommended. J Am Coll Cardiol, 1997 Oct, 30(4), 1072 - 8 Role of echocardiography in evaluation of patients with Staphylococcus aureus bacteremia: experience in 103 patients; Fowler VG Jr et al.; OBJECTIVES: The purpose of this prospective study was to examine the role of echocardiography in patients with Staphylococcus aureus bacteremia (SAB) . BACKGROUND: The reported incidence of infective endocarditis (IE) among patients with SAB varies widely . Distinguishing patients with uncomplicated bacteremia from those with IE is therapeutically and prognostically important, but often difficult . METHODS: One hundred-three consecutive patients undergoing both transthoracic (TTE) echocardiography and transesophageal (TEE) echocardiography were prospectively evaluated . All patients presented with fever and > or = 1 positive blood culture and were followed up for 12 weeks . RESULTS: Although predisposing heart disease was present in 42 patients (41%), clinical evidence of infective endocarditis (IE) was rare (7%) . TTE revealed anatomic abnormalities in 33 patients, but vegetations in only 7 (7%), and was considered indeterminate in 19 (18%) . TEE identified vegetations in 22 patients (aortic valve in 5, mitral valve in 9, tricuspid valve in 4, catheter in 2 and pacemaker in 2, abscesses in 2, valve perforation in 1 and new severe regurgitation in 1; 26 total {25%}) . Using Duke criteria for the diagnosis of IE, definite IE was present in 26 patients (25%) . Clinical findings and predisposing heart disease did not distinguish between patients with and without IE . The sensitivity of TTE for detecting IE was 32%, and the specificity was 100% . The addition of TEE increased the sensitivity to 100%, but resulted in one false positive result (specificity 99%) . TEE detected evidence of IE in 19% of patients with a negative TTE and 21% of patients with an indeterminate TTE . At follow-up, cure of staphylococcal infection occurred in a similar percentage of patients with and without IE (77% and 75%, respectively) . However, death due to sepsis was significantly more likely among patients with IE (4 of 26 {15%}) than among those without IE (2 of 77 {3%}) (p = 0.03) . CONCLUSIONS: Our results suggest that IE is common among patients admitted to the hospital with SAB and is associated with an increased risk of death due to sepsis . TEE is essential to establish the diagnosis and to detect associated complications . Therefore, the test should be considered part of the early evaluation of patients with SAB. Infect Immun, 1997 Oct, 65(10), 4048 - 54 Vbeta-dependent stimulation of bovine and human T cells by host-specific staphylococcal enterotoxins; Deringer JR et al.; Staphylococcus aureus isolates from bovine and ovine species produce unique molecular variants of type C staphylococcal enterotoxin (SEC) . The SEC animal variants have greater than 98% amino acid sequence identity with SEC1, a human-associated SEC . The two SEC animal variants have been designated SEC(bovine) and SEC(ovine) according to their corresponding host species . We showed previously that these toxins induce quantitatively different levels of T-cell stimulation in several animal species . The present study compared the abilities of these closely related host-specific SEC variants to stimulate Vbeta-bearing T cells from bovine and human donors . All three toxins expanded human T cells bearing T-cell receptor Vbeta elements (huVbeta) 3, 12, 13.2, 14, 15, 17, and 20 . However, SEC1 resulted in greater expansion of hyVbeta12 than either SEC(bovine) or SEC(ovine) . In addition, bovine T cells proliferate in a Vbeta-dependent manner in response to these superantigens (SAgs) . All three toxins induced the proliferation of bovine T cells bearing the previously sequenced Vbeta element (boVbeta) from the bovine T-cell clone BTB13 (boVbetaBTB13) . SEC1 and SEC(ovine) also were able to induce proliferation of bovine T cells bearing boVbetaBTB35, which SEC(bovine) failed to stimulate . The species-specific differences in T-cell proliferation exhibited by these closely related SEC variants may reflect the evolutionary adaptation of S . aureus, presumably to increase its host range by the manipulation of the immune system in a host-specific manner. Infect Immun, 1997 Oct, 65(10), 4030 - 7 Nitric oxide regulates clonal expansion and activation-induced cell death triggered by staphylococcal enterotoxin B; Bras A et al.; Increased interest has recently been focused on nitric oxide (NO) due to its several biological roles . Apart from being a potential antimicrobial defense and a mediator of autoimmune diseases, NO also appears to be a strong mediator of T-cell responses . In this report, we have characterized the effect of NO on T-cell function . For this purpose, we analyzed in vivo T-cell responses to the bacterial superantigen produced by Staphylococcus aureus, staphylococcal enterotoxin B (SEB), in mice treated with an NO donor (isosorbide dinitrate {ISO}) . We show that ISO partially prevents SEB-triggered activation-induced cell death of spleen and lymph node CD4Vbeta8+ T cells but not of CD8Vbeta8+ T cells . SEB-promoted thymic deletion is not abolished by ISO; however, a rapid recovery of thymocyte numbers due to increased double-positive (DP) CD4+ CD8+ thymocyte proliferation was clearly observed in ISO-treated, SEB-injected mice but not in controls (untreated SEB-injected mice) . It was also found that ISO inhibits the early SEB-induced cell proliferation (i.e., that found 12 h after SEB injection), accelerating the clonal anergy usually observed 3 days after SEB injection . Inhibition of T-cell proliferation by the NO donor does not appear to be due to inhibition of cytokine production . These results show that NO interferes with apoptosis and facilitates thymic proliferation of DP thymocytes, although it inhibits peripheral T-cell proliferation. J Clin Microbiol, 1997 Oct, 35(10), 2580 - 7 Typing of Staphylococcus aureus and Staphylococcus epidermidis strains by PCR analysis of inter-IS256 spacer length polymorphisms; Deplano A et al.; IS256 elements are present in multiple copies in the staphylococcal genome, either flanking the transposon Tn4001 or independent of it . PCR-based analysis of inter-IS256 spacer polymorphisms was developed for typing of methicillin-resistant Staphylococcus aureus (MRSA) and Staphylococcus epidermidis strains . Using SmaI macrorestriction analysis resolved by pulsed-field gel electrophoresis (PFGE) as the reference method for MRSA typing, excellent reproducibility (100%), discriminatory power (97%), and in vivo stability were observed . Good concordance of the results with those of other molecular typing methods was found for two MRSA collections . Inter-IS256 PCR analysis of a U.S . collection of MRSA strains (n = 36), previously characterized by 15 typing methods, showed more limited discrimination . Agreement was 78% with PFGE analysis and 83% with ribotyping (HindIII) . Analysis of a second set of Belgian MRSA strains (n = 17), categorized into two widespread epidemic clones by PFGE analysis, showed 65% agreement . For typing of S . epidermidis strains (n = 26), inter-IS256 PCR showed complete typeability (100%) and good discriminatory power (85%) . Inter-IS256 PCR analysis is proposed as an efficient molecular typing assay for epidemiological studies of MRSA or S . epidermidis isolates. J Clin Microbiol, 1997 Oct, 35(10), 2514 - 20 Clonal analysis and identification of epidemic strains of methicillin-resistant Staphylococcus aureus by antibiotyping and determination of protein A gene and coagulase gene polymorphisms; Hoefnagels-Schuermans A et al.; Forty-three methicillin-resistant Staphylococcus aureus (MRSA) isolates with known genetic and epidemiological relatedness and different degrees of transmission were analyzed by antibiotyping, protein A gene polymorphism analysis, and coagulase gene polymorphism analysis . The three typing systems were evaluated for their performance and convenience to define clones and to discriminate between epidemic MRSA (EMRSA) and sporadic MRSA (SMRSA) . Antibiotyping and AluI restriction fragment length polymorphism analysis of the coagulase gene were able to define clones in the same way as DNA macrorestriction analysis (SmaI) . However, both techniques presented disadvantages, making neither of them useful as a single typing method . Protein A gene polymorphism analysis appeared to be of no value for clonal analysis . None of the three typing methods was able to differentiate between EMRSA and SMRSA. J Clin Microbiol, 1997 Oct, 35(10), 2444 - 9 Comparative evaluation of use of cna, fnbA, fnbB, and hlb for genomic fingerprinting in the epidemiological typing of Staphylococcus aureus; Smeltzer MS et al.; We used a genomic fingerprinting protocol to characterize 59 Staphylococcus aureus strains and a single S . intermedius isolate, all of which were previously typed by 13 different methods (F . C . Tenover et al., J . Clin . Microbiol . 32:407-415, 1994) . These 60 strains were divided into three groups of 20 strains each, with each group including internal controls . Two of the three groups (groups SB and SC) included 29 strains from four relatively well-defined outbreaks . The epidemiological relationships of the strains in the third group (group SA) were unclear . Fingerprints were established by Southern blotting with HaeIII-digested genomic DNA and a probe mixture consisting of DNA fragments corresponding to the S . aureus collagen adhesin (cna), fibronectin-binding protein (fnbA and fnbB), and beta-toxin (hlb) genes . An unambiguous fingerprint was obtained for all S . aureus isolates . No hybridization signal was observed with S . intermedius . Twenty-seven of the 29 related strains in the SB and SC groups were correctly identified as belonging to one of the four epidemiologically related groups . Our protocol was less successful with respect to the exclusion of unrelated strains . Specifically, only 6 of 11 unrelated strains in the SB and SC groups had a fingerprint that was distinct by comparison to the fingerprints of the outbreak strains . Nevertheless, our protocol was relatively accurate by comparison to the accuracies of the other methods and was one of only six methods that accurately identified all of the repetitive strains included as internal controls. Trop Anim Health Prod, 1997 Aug, 29(3), 147 - 50 Rapid diagnosis of fowl pox with coagglutination assay; Joshi RK et al.; The coagglutination test was standardised for detection of fowl pox antigen in infected scabs and chorioallontoic membrane of chicken embryos . The Staphylococcus aureus Cowan I strain, containing large amounts of Protein A in their cell wall, coated with fowl pox antibodies was found specific and sensitive for detection of fowl pox antigen . The test is easy to perform and rapid as the positive results can be read within 15 seconds. Scand J Immunol, 1997 Sep, 46(3), 235 - 41 Production of interferon-alpha/beta by murine dendritic cell lines stimulated by virus and bacteria; Eloranta ML et al.; The interferon-alpha and -beta (IFN-alpha/beta) producing ability of the two murine dendritic cell (DC) lines D2SC/1 and FSDC was studied . The D2SC/1 cells produced IFN-alpha and -beta when stimulated by herpes simplex virus (HSV), Sendai virus (SV) or by the bacteria Escherichia coli or Staphylococcus aureus Cowan I . Precultivating (priming) D2SC/1 cells with recombinant IFN-beta or a combination of IFN-beta and granulocyte-macrophage colony-stimulating factor increased production of IFN-alpha/beta induced by HSV or the bacteria, but not by SV . Also, the kinetics of IFN-alpha/beta responses were different for SV compared to HSV and the bacteria, suggesting different induction mechanisms . The FSDC cells differed from the D2SC/1 cells mainly in that predominantly IFN-beta was produced, that little or no IFN-alpha/beta production was induced by the bacteria, and that the IFN-alpha/beta responses were most efficiently primed by IFN-gamma . Priming the DC lines with tumour necrosis factor-alpha, interleukin-10 (IL-10) or IL-4 did not affect the IFN-alpha/beta response induced by HSV . The results show that the two DC lines provide a convenient tool to study the induction and control of the IFN-alpha/beta response, as well as the immunoregulatory role of IFN-alpha/beta produced by DC. Clin Infect Dis, 1997 Sep, 25(3), 698 - 705 Rapid geographic spread of a methicillin-resistant Staphylococcus aureus strain; Roman RS et al.; In May 1993, an outbreak of methicillin-resistant Staphylococcus aureus (MRSA) was identified at our tertiary care teaching center . The epidemic MRSA strain was transmitted efficiently in the hospital environment . Subsequent investigations indicated that the strain had been introduced into western Canada by a patient who had recently been hospitalized for 3 months in the Punjab, India, and had been admitted to a hospital in rural British Columbia shortly after his arrival in Canada . Transfer of the patient to a hospital in Vancouver and subsequent transfer of a colonized patient contact to a hospital in Winnipeg, Manitoba, resulted in major outbreaks of MRSA at these two large tertiary care centers within 6 weeks of the arrival of the index case in Canada . Epidemiological typing of the S . aureus coagulase gene with use of a polymerase chain reaction method and pulsed-field gel electrophoresis documented clonality of this strain . These outbreaks again illustrate both the propensity of certain strains of S . aureus to produce epidemic disease, including rapid spread within the institutional setting, and the global nature of problems with antimicrobial resistance. Clin Infect Dis, 1997 Sep, 25(3), 647 - 53 Reemergence of gentamicin-susceptible strains of methicillin-resistant Staphylococcus aureus: roles of an infection control program and changes in aminoglycoside use; Aubry-Damon H et al.; The spread of methicillin-resistant Staphylococcus aureus (MRSA) in our hospital in the 1980s correlated with increasing acquisition of resistance to antibiotics including gentamicin, rifampin, and fluoroquinolones . During the period 1993-1995, there was a major change in clinical MRSA isolates: the percentage of aminoglycoside-resistant MRSA isolates decreased from 75% to 52%, while the proportion of heterogeneous MRSA strains susceptible to gentamicin, rifampin, and tetracycline increased gradually from 4.9% to 27.5% . We used five epidemiological markers (i.e., antibiotyping, phage typing, pulsed-field gel electrophoresis, and restriction analysis of PCR amplified coagulase and protein A genes) to characterize recent isolates . With use of these techniques, we confirmed the persistence of the aminoglycoside-resistant MRSA clone and identified a clone of erythromycin-susceptible strains among the gentamicin-susceptible isolates and found that the remaining strains were diverse . These changes were due to the introduction of various MRSA strains from outside the hospital, while implementation of infection control measures in 1991 could have led to reduced transmission of the aminoglycoside-resistant MRSA strain . Changes in antibiotic prescribing patterns that resulted in reduced selective pressure from gentamicin may have contributed to the spread of gentamicin-susceptible MRSA strains. Hypertension, 1997 Sep, 30(3 Pt 1), 442 - 8 Calcium sensitivity and agonist-induced calcium sensitization in small arteries of young and adult spontaneously hypertensive rats; Shaw LM et al.; The sensitivity of the myofilaments to Ca2+ is increased during agonist-induced contraction of vascular smooth muscle . Given the important contribution of vascular tone to the elevation of peripheral resistance observed in genetic hypertension, we have investigated whether alterations in myofilament Ca2+ sensitivity occur in small arteries from spontaneously hypertensive rats (SHR) and age-matched Wistar-Kyoto (WKY) controls during the developmental and established phases of hypertension . Segments of mesenteric, renal, and femoral artery with an average lumen diameter <300 microm from 5- or 20-week-old rats were mounted in a wire myograph . Morphological measurements were made and the vessels permeabilized with Staphylococcus aureus alpha-toxin . Dose-response curves to increasing concentrations of Ca2+ were obtained and the ability of 100 nmol/L endothelin-1 (ET-1) or 10 micromol/L norepinephrine (NE) in the presence of 10 micromol/L GTP to enhance tension in response to low Ca2+ (pCa6.7) was determined . Systolic, diastolic, and mean blood pressures were higher in SHR than in WKY at 5 and 20 weeks . The media thickness:lumen diameter ratio was increased in mesenteric and femoral arteries from SHR compared with WKY at 5 and 20 weeks . There was no difference in media thickness:lumen diameter ratio in renal arteries or between 5- and 20-week animals in any vascular bed . The pCa curves were not different in mesenteric, renal, or femoral arteries from hypertensive compared with normotensive rats or between age groups, except in femoral arteries at 20 weeks, which exhibited a greater sensitivity to Ca2+ in SHR . Tension developed in response to maximal Ca2+ (pCa5.0) was greater in permeabilized mesenteric arteries from SHR compared with WKY at 20 weeks of age only; media stress was again similar in both strains but increased in older animals compared with younger animals in mesenteric arteries from WKY . The submaximal contraction induced by pCa6.7 was greater in femoral and renal than mesenteric arteries . GTP (10 micromol/L) augmented the tension developed to pCa6.7 in mesenteric arteries at 5 and 20 weeks and in renal arteries at 20 weeks . Addition of 100 nmol/L ET-1 or 10 micromol/L NE in the continued presence of GTP markedly increased tension in mesenteric arteries at 5 and 20 weeks . In renal arteries, 10 micromol/L NE enhanced Ca2+ sensitivity in the presence of GTP in SHR at 5 and 20 weeks and WKY at 5 weeks . In femoral arteries, there was a tendency for ET-1 and NE to increase Ca2+ sensitivity, but this increase was significant in WKY at 20 weeks (ET-1) and SHR at 5 weeks (NE) only . We have demonstrated that the sensitivity of the myofilaments to Ca2+ and ET-1- or NE-induced Ca2+ sensitization is not different in permeabilized small mesenteric, renal, or femoral arteries from SHR compared with WKY controls . Only in SHR mesenteric arteries at 20 weeks of age was there evidence of increased active tension in response to maximal Ca2+, despite structural differences, consistent with increased muscle mass in femoral arteries from SHR . We conclude that it is unlikely that a ubiquitous abnormality of the sensitivity of the contractile apparatus to Ca2+ or agonist-induced Ca2+ sensitization in vascular smooth muscle underlies the elevated total peripheral resistance associated with hypertension. J Dairy Sci, 1997 Sep, 80(9), 2025 - 34 Immune recruitment and bactericidal activity of neutrophils in milk of cows vaccinated with staphylococcal alpha-toxin; Herbelin C et al.; The ability of Staphylococcus aureus alpha-toxin to recruit neutrophils in the milk of vaccinated cows and the bactericidal efficiency of these neutrophils were evaluated . Six lactating Holstein cows that were free of intramammary infection received systemic immunization by subcutaneous injection of Freund's incomplete adjuvant with alpha-toxin (n = 2), alpha-toxin mixed with type 5 capsular polysaccharide (n = 2), or a conjugate of these two antigens (n = 2) . Controls (n = 4) and vaccinated cows (n = 6) received intramammary infusions of alpha-toxin . No increase in somatic cell count was recorded in quarter milk samples from unimmunized cows; however, 10 micrograms of alpha-toxin induced a local inflammatory reaction in vaccinated cows that was characterized by early and massive cellular recruitment into the mammary gland . More than 90% of the recruited cells were neutrophils . The speed and magnitude of the cellular recruitment were dose-dependent; the threshold dose was 0.6 microgram . Milk samples showed significant bactericidal activity against the type 5 S . aureus strain, regardless of the vaccine used, and showed a decrease in bacterial count of about 2 log10 from the initial inoculum . The best efficiency was recorded during the early phase of cellular recruitment with concomitant activation of blood-derived neutrophils . This study demonstrates that a bacterial virulence factor, alpha-toxin, is able to induce immune recruitment of neutrophils for efficient bactericidal activity in milk when cows are immunized with alpha-toxin that is used either as a nonconjugate vaccinate or as a carrier protein in a conjugate vaccine . The study also suggests that neutrophils that are recruited from blood are activated during inflammation in response to specific antigens. Pediatr Med Chir, 1997 Mar-Apr, 19(2), 129 - 31 {Presence of a monoclonal component IgG lambda in a 17-day-old newborn with omphalitis caused by Staphylococcus aureus}; Camerotto A et al.; Monoclonal components are usually found in elderly patients . They are rarely noted in children, both because of their slight presence, and because the very low concentration makes it difficult to single them out . This report is about the identification of a transitory IgG lambda monoclonal component in a 17 day old baby suffering from aureus Staphylococcus . Electrophoresis was carried out with automatic equipment on cellulose acetate; immunofixation with a manual method on agarose gel; the quantitative doses of the immunoglobulins, reactive protein C and alpha 1-acid glycoprotein with nephelometric technique, the erythrocyte sedimentation rate with automatic equipment . The importance of singling out monoclonal components in children must be emphasized, inasmuch as it may be a sign of an immunological disorder, usually benign and transitory, but sometimes extremely serious. J Biol Chem, 1997 Oct 3, 272(40), 24858 - 63 The role of the amino terminus in the kinetics and assembly of alpha-hemolysin of Staphylococcus aureus; Vandana S et al.; The nature of the involvement of an intact NH2 terminus in the assembly of alpha-hemolysin of Staphylococcus aureus was reinvestigated . For the first time, a deletion of the first four amino acids at the NH2 terminus of alpha-hemolysin yielded a novel mutant that undergoes all of the conformational changes to form a lytic pore . The experimental evidence shows unequivocally that the mutant toxin forms heat- and sodium dodecyl sulfate-stable heptameric oligomers . The concentration required to achieve 50% lysis of red blood cells is around 58-116 ng/ml, and the time taken to achieve lysis to the same extent as that of intact toxin is considerably longer . Transmission electron microscopic studies also suggest that the pores formed by this deletion mutant are similar to those by the full-length toxin . This is in contrast to the previously reported 2- and 11-amino acid deletions that failed to proceed further from a presumed prefinal nonlytic pore to a lytic pore . Studies on the kinetics of assembly indicate that this mutant can form heat- and sodium dodecyl sulfate-stable oligomers as fast as full-length alpha-hemolysin but that pore opening is slowed down . The data strongly suggest that these amino acids (Ala-Asp-Ser-Asp) are involved in the final stages of assembly of alpha-hemolysin in target membranes. J Virol, 1997 Oct, 71(10), 7488 - 97 Caprine arthritis encephalitis virus dysregulates the expression of cytokines in macrophages; Lechner F et al.; Caprine arthritis encephalitis virus (CAEV) is a lentivirus of goats that leads to chronic mononuclear infiltration of various tissues, in particular, the radiocarpal joints . Cells of the monocyte/macrophage lineage are the major host cells of CAEV in vivo . We have shown that infection of cultured goat macrophages with CAEV results in an alteration of cytokine expression in vitro . Constitutive expression of interleukin 8 (IL-8) and monocyte chemoattractant protein 1 (MCP-1) was increased in infected macrophages, whereas transforming growth factor beta1 (TGF-beta1) mRNA was down-regulated . When macrophages were infected with a CAEV clone lacking the trans-acting nuclear regulatory gene tat, IL-8 and MCP-1 were also increased . No significant differences from cells infected with the wild-type clone were observed, suggesting that Tat is not required for the increased expression of IL-8 and MCP-1 in infected macrophages . Furthermore, infection with CAEV led to an altered pattern of cytokine expression in response to lipopolysaccharide (LPS), heat-killed Listeria monocytogenes plus gamma interferon, or fixed cells of Staphylococcus aureus Cowan I . In infected macrophages, tumor necrosis factor alpha, IL-1beta, IL-6, and IL-12 p40 mRNA expression was reduced in response to all stimuli tested whereas changes in expression of granulocyte-macrophage colony-stimulating factor depended on the stimulating agent . Electrophoretic mobility shift assays demonstrated that, in contrast to effects of human immunodeficiency virus infection of macrophages, CAEV infection had no effect on the level of constitutive nuclear factor-kappaB (NF-kappaB) activity or on the level of LPS-stimulated NF-kappaB activity, suggesting that NF-kappaB is not involved in altered regulation of cytokine expression in CAEV-infected cells . In contrast, activator protein 1 (AP-1) binding activity was decreased in infected macrophages . These data show that CAEV infection may result in a dysregulation of expression of cytokines in macrophages . This finding suggests that CAEV may modulate the accessory functions of infected macrophages and the antiviral immune response in vivo. MMWR Morb Mortal Wkly Rep, 1997 Sep 5, 46(35), 813 - 5 Update: Staphylococcus aureus with reduced susceptibility to vancomycin--United States, 1997; Outbreak among HIV-infected patients of Staphylococcus aureus resistant to cotrimoxazole and methicillin; Servicio de Microbiologia Clinica y Enfermedades Infecciosas, Hospital General Universitario Gregorio Maranon, Madrid, SpainOBJECTIVE: To describe an outbreak of trimethoprim-sulfamethoxazole (cotrimoxazole)-resistant and methicillin-resistant Staphylococcus aureus (CMRSA) in a unit housing patients infected with the human immunodeficiency virus (HIV) . DESIGN: Prospective study involving patients colonized or infected with CMRSA . PATIENTS: 15 hospitalized patients with cultures positive for CMRSA . METHODS: Isolates of CMRSA were collected and characterized . Molecular typing of the epidemic strains was carried out after total DNA extraction by restriction endonuclease analysis and random amplification of polymorphic DNA . RESULTS: The epidemic was brought under control with the reinforcement of nosocomial transmission measures and with systematic nasal decontamination with mupirocin of all patients admitted to the HIV unit . Molecular typing techniques showed the existence of two epidemic strains: strain A was present in the 12 patients admitted to the HIV unit and strain B in the remaining 3 patients hospitalized elsewhere . CONCLUSIONS: Cotrimoxazole may no longer be a reliable and effective alternative for glycopeptides in patients with infection caused by MRSA strains, and HIV units should be particularly alert for CMRSA strains. Microbiology, 1997 Sep, 143 ( Pt 9), 2877 - 82 The Staphylococcus aureus scdA gene: a novel locus that affects cell division and morphogenesis; Brunskill EW et al.; A new Staphylococcus aureus gene termed scdA was found upstream of the autolysis regulatory genes, lytS and lytR, and was shown to potentially encode a hydrophilic 25 kDa protein . Analysis of scdA transcription revealed that it is transcribed as a monocistronic message and is lytSR-independent . A role in cell wall metabolism was indicated by examination of the scdA mutant S . aureus KB323, which had a grossly aberrant cellular morphology and formed large cell clusters when grown in liquid culture medium . Furthermore, KB323 exhibited a reduced rate of autolysis and had increased peptidoglycan cross-linking compared to the parental strain, NCTC 8325-4 . These data suggest that scdA plays an important role in staphylococcal cell division. Postgrad Med J, 1997 Aug, 73(862), 507 - 8 Effects of cabergoline in a pituitary adenoma secreting follicle-stimulating hormone; Leese G et al.; A patient with a pituitary adenoma secreting follicle-stimulating hormone with co-existent primary hyperaldosteronism is described . After his second transsphenoidal surgery, the patient developed a Staphylococcus aureus pituitary abscess . Symptoms improved after abscess drainage . Subsequent cabergoline therapy arrested the deterioration of symptoms . and decreased serum follicle-stimulating hormone concentrations . Cabergoline may be a useful treatment for aggressively growing non-prolactin-secreting pituitary adenomas. Med Trop (Mars), 1997, 57(2), 186 - 94 {Suppurative intracranial infections in Africa}; Loembe PM et al.; The purpose of this study was to review recent African literature on suppurative intracranial infection and its implications for neurosurgery . In order of decreasing frequency the main lesions are brain abscess, subdural empyema, and epidural abscess . Despite progress in diagnostic imaging and availability of antibiotic therapy, these lesions still cause disturbingly high morbidity and mortality especially in sub-Saharan Africa where diagnosis is often delayed . The male-to-female ratio was 3.6:1 and 70 to 80% of patients were under the age of 20 years . Spread from the paranasal sinus or ear was the most common mechanism of infection . Hematogenous processes accounted for 22% of cases and the origin was undetermined in 11% to 26% of cases . Staphylococcus aureus and enteric gram-negative bacilli were the most common bacteria identified but cultures were reported as sterile in 30% to 50% of cases . While ultrasonography can be useful in newborns with an open fontanelle, arteriography is often the only feasible procedure for diagnosis in Black Africa . The diagnostic modality of choice is computed tomography which allows precise mapping prior to neurosurgery . Introduction of computed tomography in some African cities has led to a decrease in mortality ranging from 4.7% to 43% . The most effective treatment is a combination of appropriate antimicrobial therapy and surgical decompression of expanding lesions . The main procedures are aspiration through burr holes and craniotomy . Use of this combined strategy requires close cooperation between the neurosurgeon, infectious disease specialist, and microbiologist . Therapeutic indications are discussed within the context of Black Africa. Fiziol Zh, 1997, 43(3-4), 25 - 32 {Human specific transfer factor to Staphylococcus aureus antigens}; Liubchenko TA et al.; Immunobiological properties of human specific transfer factor (TF) to Staphylococcus aureus antigens were studied . It is shown that this TF activated human leucocytes in vitro as well as in vivo . Antigen specificity of TF's immunomodulating effects is also shown . In vitro we used leucocyte migration inhibition test (IML), macrophage inhibition test (MPI) and rosette formation (E-ros) . For testing in vivo we used delayed type hypersensitivity (DTH) skin tests. Antimicrob Agents Chemother, 1997 Sep, 41(9), 2023 - 5 Association of mutations in grlA and gyrA topoisomerase genes with resistance to ciprofloxacin in epidemic and sporadic isolates of methicillin-resistant Staphylococcus aureus; Deplano A et al.; The types of topoisomerase alterations in genomically diverse epidemic and sporadic strains of methicillin- and fluoroquinolone-resistant Staphylococcus aureus isolated from European hospitals between 1984 and 1994 were characterized . Convergent dual mutations in gyrA (codon 83, 84, or 88) and grlA (codon 79 and/or 80) were found in all strains exhibiting high-level resistance to ciprofloxacin (MIC, 16 to > or = 128 microg/ml) . In some epidemic strains, the resistant phenotype and genotype appeared in the 1990s and persisted thereafter. Ann Otol Rhinol Laryngol, 1997 Sep, 106(9), 751 - 2 Bacterial flora of stethoscopes' earpieces and otitis externa; Brook I; External otitis caused by Staphylococcus aureus was observed in a nurse after extensive use of a stethoscope . The infection recurred and a similar organism was isolated from the stethoscope's earpiece . The infection did not recur after the earpiece was cleansed after each use . In a prospective study, the bacterial flora of 35 earpieces was evaluated . Fifty-three isolates, 36 aerobic or facultative and 17 anaerobic, were recovered . The number of organisms per earpiece ranged from 14 to 204 (average 92 +/- 17) . The predominant isolates were Staphylococcus epidermidis (16 isolates), Propionibacterium acnes (12), and Saureus (7) . The study demonstrates the colonization of the stethoscope's earpiece with microorganisms that possess the potential for causing nosocomial infection. Biosci Biotechnol Biochem, 1997 Aug, 61(8), 1286 - 91 Purification and characterization of the acid soluble 26-kDa polypeptide from soybean seeds; Momma M et al.; Whey proteins from soybean seeds of Japanese varieties were analyzed by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) . Among 11 varieties of soybean, three green and one black soybeans lacked a 26-kDa band that was found in all yellow soybeans . In this paper, the 26-kDa protein was named AS26k (acid soluble 26-kDa protein) temporarily . The AS26k protein was purified from Glycine max cv . Nattosyoryu, which is yellow soybean, through four purification steps: 30-35% saturated ammonium sulfate fractionation, ion exchange chromatography on S Sepharose Fast Flow, gel filtration on Sephadex G-100, and hydrophobic chromatography on phenyl Sepharose CL-4B . Purified AS26k was cleaved with V8 proteinase from Staphylococcus aureus or CNBr . The cleaved polypeptide contained two typical dehydrin motif sequences: DEYGNPV and (M)DKIKEKLPG, and a 19 amino acids sequence similar to a pea dehydrin . Native AS26k had a molecular mass of 32 kDa on gel filtration and a pl of 7.2 on two-dimensional PAGE . Similarly to other dehydrins and late embryogenesis abundant (LEA) proteins, AS26k was rich in hydrophilic amino acids, and highly heat stable . These results showed that AS26k was a dehydrin, a group II LEA protein in soybean seeds. Spinal Cord, 1997 Sep, 35(9), 617 - 9 Psychological impact of the management of methicillin-resistant Staphylococcus aureus (MRSA) in patients with spinal cord injury; Kennedy P et al.; BACKGROUND: Management of MRSA infection includes immediate isolation of the patient . Long periods of isolation are considered to be psychologically detrimental, though little information is available about the impact of isolation as an infection control procedure . The purpose of this study is to examine the psychological well-being of spinal cord injured patients who are isolated as a result of being MRSA positive . METHODS: A cross-sectional matched-control study of MRSA positive patients with MRSA negative patients was carried out at the National Spinal Injuries Centre, Stoke Mandeville Hospital, Bucks, England . Sixteen MRSA positive patients, aged 18 to 65, and their matched controls completed a series of questionnaires to measure aspects of psychological impact . The measures used were functional independence, depression, anxiety, and the affective states of anger, vigour, fatigue and confusion . FINDINGS: The MRSA positive spinal cord injured patients were only significantly more angry than the control group, although these isolated patients scored higher in all measures . INTERPRETATIONS: In this spinal cord injured group the difference between the psychological well-being of isolated MRSA positive patients and non-isolated MRSA negative patients is not as great as might have been expected . Patients feel that rehabilitation is affected, but the situation may be improved by providing more space and a better view onto the ward. J Immunol, 1997 Sep 15, 159(6), 2849 - 57 Metacyclogenesis modulates the ability of Leishmania promastigotes to induce IL-12 production in human mononuclear cells; Sartori A et al.; Immunity against the intracellular protozoan Leishmania species is highly dependent on Th1 development . We have previously shown that IL-12 is a powerful and probably obligatory factor for Th1 cell generation and proliferation . We also observed that the experimental infection of C3H and BALB/c mice with Leishmania major is associated with IL-12 production in vivo . Now we demonstrate that metacyclic L . major promastigotes are poor inducers of IL-12 in vitro in fresh human PBMC and monocytes . In addition, we show that the ability of this pathogen to induce IL-12 and other cytokines is modulated by the metacyclogenic process, which had previously not been recognized . In contrast to the infective parasites (metacyclic promastigotes), the procyclic promastigotes collected at the logarithmic phase of the culture displayed a striking ability to induce IL-12, IFN-gamma, TNF-alpha, and IL-10 . Despite this differential effect of procyclic and metacyclic parasites in terms of IL-12 induction, both stages were inhibitory for IL-12 production induced by Staphylococcus aureus . The ability of procyclic promastigotes and, to a much lesser extent, that of metacyclic promastigotes to induce IL-12 were enhanced by pretreatment of monocytes in a cytokine milieu containing IFN-gamma, IL-4, IL-13, or granulocyte-macrophage CSF or by neutralization of endogenous IL-10 . Our results suggest the development of an evasion mechanism as the Leishmania promastigotes mature to infectious forms and the possibility of using Ags derived from procyclic promastigotes for immunization procedures. J Immunol, 1997 Sep 15, 159(6), 2652 - 7 CD154/CD40 and CD70/CD27 interactions have different and sequential functions in T cell-dependent B cell responses: enhancement of plasma cell differentiation by CD27 signaling; Jacquot S et al.; CD40, a TNF receptor family member, plays a central role in T cell-mediated B cell activation . We have recently demonstrated that CD27, another TNF receptor family member, was also involved in B cell regulation and enhanced Ig production . In this report we compare CD27 and CD40 signals in B cell function . We selectively mimicked the effect of T cell help by addition to peripheral blood B cells activated with Staphylococcus aureus Cowan I strain and IL-2 of irradiated 300-19 cells transfected with either the CD70 (CD27 ligand) gene or the CD154 (CD40 ligand) gene, the vector alone, or both CD70 and CD154 genes . CD27 ligation induced only a slight increase in B cell proliferation compared with the dramatic enhancement induced by CD40 ligation; double ligation proved to be less efficient than CD40 ligation alone . In contrast, IgG production was increased only by CD27 ligation alone . Moreover, the CD27 signal was more efficient when it was given on day 2 of the culture rather than on day 0 . Phenotypic analysis of the activated cells showed that CD27 ligation increased the percentage of cells showing a plasma cell profile (CD19-, CD38+), whereas upon CD40 ligation most of the cells still had a germinal center-like phenotype (CD19+, CD38+) . Our results suggest that the CD27 and CD40 signals are not synergistic but, rather, are complementary and involve distinct steps of T cell-dependent B cell activation . CD27 may be more important in the induction of plasma cell differentiation at a time when the expansion phase has already occurred. J Okla State Med Assoc, 1997 Jul-Aug, 90(6), 228 - 35 Methicillin-resistant Staphylococcus aureus at a Veterans Affairs Medical Center (1986-96); Flournoy DJ; Methicillin-resistant Staphylococcus aureus (MRSA) isolates are endemic at the Veterans Affairs Medical Center in Oklahoma City . Five hundred and four consecutively occurring pathogenic MRSA from 490 in-patients were characterized from 1986-96 in order to better understand their epidemiology . The percentage of S . aureus resistant to methicillin increased steadily for 8 years then unexpectedly began decreasing in 1994 . During the study period there was a decrease in nosocomial MRSA from wounds and urines with an increase in community-acquired MRSA from sputa and wounds . However, 72% of all isolates from 1986-96 were nosocomial . MRSA from intensive care unit (ICU) patients were more likely to come from respiratory tract specimens than MRSA from non-ICU patients . During the study period, increases in the proportions of nosocomial MRSA from ICU patients and community acquired MRSA from ICU and non-ICU patients occurred . MRSA with many phenotypes (i.e., 69) were identified, suggesting a divergent (versus univergent) threat to patients . Phenotypic analyses, weekly tabulations, and other evidence suggested that MRSA from 3 of the 69 phenotypes were epidemic strains, occurring around 1989 . This 11-year descriptive study revealed the epidemiology of MRSA to be a continuously evolving, complicated multifactoral process. Biochem Biophys Res Commun, 1997 Aug 28, 237(3), 554 - 8 Identification of nitric oxide synthase in Staphylococcus aureus; Choi WS et al.; The presence of nitric oxide synthase (NOS) in Staphylococcus aureus ATCC6538P was established by western blot analysis . The identity of citrulline formed from L-arginine by the NOS was confirmed by both TLC and HPLC and the other product, NO, by directly measuring the production of nitrogen oxides (NOx) in the reaction mixture . The activity was inhibited by typical NOS inhibitors such as N-nitro-L-arginine methylester and NG,NG-dimethyl-L-arginine with the IC50 of 4.9 x 10(-4) and 2.5 x 10(-4) M, respectively . The NOS activity was maximum at pH 6.5 and at 47.5 degrees C . These results indicate that the NOS of S . aureus ATCC6538P is an isoform distinct from mammalian NOS. J Foot Ankle Surg, 1997 Jul-Aug, 36(4), 322 - 5; discussion 331 Factors associated with methicillin resistance in diabetic foot infections; Day MR et al.; Methicillin-resistant staphylococcal infections often present a challenge to physicians treating patients with pedal wounds . Most methicillin-resistant Staphylococcus aureus infections have been thought of as nosocomial in origin . Several studies have identified specific modes of transmission via hospital reservoirs such as the anterior nares of the patient, inanimate objects within close proximity of the patient, and direct contamination from health care providers . Exposure of patients to these reservoirs through hospitalization has been shown to increase the patient's risk of obtaining a methicillin-resistant S . aureus infection . Diabetic patients with a high risk for foot complications may be in greater danger of developing a methicillin-resistant S . aureus infection in that repeated hospitalizations, lengthier hospital stays, and the presence of open wounds facilitate exposure to these reservoirs. J Foot Ankle Surg, 1997 Jul-Aug, 36(4), 301 - 5 Acute hematogenous osteomyelitis in intravenous drug users; Fox IM et al.; The authors report a case of acute hematogenous osteomyelitis in a closed metatarsal fracture of an adult intravenous drug user . A transient Staphylococcus aureus bacteremia documented by blood cultures was sustained that presumably seeded the existing fracture . Osteomyelitis was documented by intraoperative cultures that matched the blood cultures and a Technetium-HMPAO-labeled leukocyte scan . Reliance on a noncompliant patient for information may have been a factor that resulted in significant morbidity in this case . Although the patient managed to do well after surgical intervention, osteomyelitis may have been avoidable . Treatment and a self-critical review of the approach to this patient population and decisions made in this case are also discussed. Eur J Pediatr Surg, 1997 Aug, 7(4), 234 - 6 Greater omentum flaps and granulocyte transfusions as combined therapy of liver abscess in chronic granulomatous disease; von Planta M et al.; We report the case of a 17-year-old boy with gp91phax-deficient chronic granulomatous disease who developed a liver abscess due to Staphylococcus aureus . Despite treatment with appropriate antibiotics and gamma interferon for three months as well as incision and drainage, the abscess persisted unchanged in size . After surgical debridement, the abscess cavity was filled with two pedunculated greater omentum flaps as a direct feeder road of granulocytes to the infectious focus . An average of 48.5 x 10(9) granulocytes a day harvested from G-CSF-prestimulated donors were transfused for a total of 8 days without side effects . Ultrasound 3 months later showed no residual abscess . Combination of greater omentum flaps and transfusion of G-CSF-prestimulated granulocytes may be the optimal treatment for liver abscesses refractory to conventional therapy. Pol Merkuriusz Lek, 1997 Jan, 2(7), 44 - 5 {Hydronephrosis in the course of primary psoas abscess}; Magier K et al.; Primary psoas abscess is rare and presents a difficult diagnostic challenge . We present an unusual case of primary psoas abscess causing hydronephrosis in a 11-year-old boy . The presence of hydronephrosis complicated diagnosis, that was definitely confirmed by computerized tomography . Percutaneous drainage of the abscess under ultrasonography guidance combined with antibiotic therapy provided an effective treatment . Culture of the pus showed Staphylococcus aureus . The subject is discussed noting incidence, etiology and methods of treatment of primary and secondary psoas abscesses. Aust N Z J Ophthalmol, 1997 Aug, 25(3), 231 - 2 Delayed microbial keratitis following radial keratotomy; Lu Y et al.; BACKGROUND: We report on the case of a 46-year-old female who presented with delayed microbial keratitis 10 years after uncomplicated radial keratotomy . METHODS: The pre- and postoperative clinical record was reviewed following her presentation to the Corneal Clinic . Slit-lamp examination revealed a stromal inflammatory infiltrate at the site of an earlier radial keratotomy incision . The lesion was scraped and a coagulase-negative Staphylococcus aureus was cultured in enrichment broth . RESULTS: The keratitis was treated successfully with combination fortified topical antibiotics without loss of vision . CONCLUSIONS: Although microbial keratitis is a well documented complication of incisional refractive procedures, it is rarely encountered as late as one decade after surgery . Patients should be warned of this possibility and the need for prompt treatment. Eur J Immunol, 1997 Aug, 27(8), 2073 - 9 B cell subpopulations separated by CD27 and crucial collaboration of CD27+ B cells and helper T cells in immunoglobulin production; Agematsu K et al.; B cell immunoglobulin production is regulated by helper T cells through direct interaction and secreted cytokines . In the present study, we functionally analyzed CD27 in cord and peripheral blood B cells . Adult peripheral blood B cells were separated into CD27+ and CD27- cells, which differed in their morphology . Cord blood B cells did not express CD27, and CD27 expression on peripheral blood B cells increased with age . Only CD27+ B cells had the ability to produce immunoglobulin, which was increased by contact with a tumor necrosis factor-related transmembrane ligand, CD70 . Adult peripheral blood CD27+ B cells can be further subdivided into two discrete subtypes: IgD- CD27+ and IgD+ CD27+ B cells . IgD- CD27+ B cells produce IgG, IgM and IgA, whereas IgD+ CD27+ B cells predominantly produce IgM . The addition of activated CD4+ CD45RO T cells expressing CD70 caused down-regulation of CD27 expression on activated B cells, and this down-modulation was completely blocked by anti-CD70 monoclonal antibody, indicating direct T-B cell contact via CD27/CD70 . The triggering via CD27 and CD40 additively increased the immunoglobulin production under Staphylococcus aureus Cowan strain plus interleukin-2 stimulation . Taken together, our findings demonstrate that peripheral blood B cells are separated into subpopulations by CD27 and IgD expression and that CD27+ B cells produce large amounts of immunoglobulin by interaction with the CD70 molecule. Eur Spine J, 1997, 6(4), 284 - 5 Brucellosis of the spine with a synchronous Staphylococcus aureus pyogenic elbow infection; Velan GJ et al.; Staphylococcus aureus osteomyelitis and pyogenic arthritis has a different pattern in the elderly than in the young . The axial skeleton is the most frequent site of infection and treatment is usually by intravenous antibiotics . We report a case of Staph . aureus septic arthritis of the elbow with concomitant osteomyelitis of the spine that was thought to be due to Staph . aureus, but culture of debrided material from the lesion grew Brucella in culture . We suggest that in the elderly it is advisable to obtain a tissue culture diagnosis and not to instigate therapy based on positive blood cultures or a concomitant infection. Am J Surg, 1997 Aug, 174(2), 157 - 9 Endovascular stent infection with delayed bacterial challenge; Hearn AT et al.; BACKGROUND: Reports of endovascular stent infection have recently been described . The purpose of this study was to determine if intravascular metallic stents in a swine model could become infected following a bacterial challenge given remote from the time of stent placement . METHODS: Balloon expandable metallic stents (Palmaz) were implanted in the iliac arteries of 14 swine . An angioplasty, without stent placement, was also performed in the contralateral iliac artery . An intravenous bacterial challenge with Staphylococcus aureus was given 4 weeks after stent placement . Euthanasia was performed 72 hours after the bacterial challenge . At the time of euthanasia, the iliac artery/stent complex and the contralateral angioplastied iliac artery were harvested and sent for microbiologic and pathologic analysis . RESULTS: Seven of the 14 stent/artery complexes were culture positive for S aureus whereas only one of the 14 angioplastied arteries was positive for S aureus (P = 0.03) . On histologic examination, 6 of the 14 stent/artery complexes had evidence of acute inflammatory changes in the arterial wall . This compares with only 1 of 14 angioplastied arteries having evidence of inflammatory infiltrate in the arterial wall (P = 0.07) . All 6 of the stent/artery complexes with inflammatory infiltrate were culture positive . CONCLUSION: In the swine model, intravascular metallic stents have the potential to become infected when a bacterial challenge is given 4 weeks after stent placement . Further studies evaluating the incidence of stent infections in humans are needed. J Rheumatol, 1997 Sep, 24(9), 1734 - 8 Pyomyositis: clinical features and predisposing conditions; Patel SR et al.; OBJECTIVE: To describe the manifestations of nontropical pyomyositis and associated comorbid conditions that may predispose to pyomyositis . METHODS: A retrospective review of 13 patients with pyomyositis seen at our center including one illustrative case report . Reports of tropical and nontropical pyomyositis were found by review of Index Medicus, Medline, and references from published cases and clinical review papers . RESULTS: All 13 patients had variable presentations including fever, muscle pain, tenderness, and swelling . Eleven patients had comorbid conditions that may have led to their infection, including one with human immunodeficiency virus and 3 with history of trauma . Staphylococcus aureus was found to be a causative organism in 7 patients, 2 patients had multiple organisms isolated, and 2 had no organisms isolated . Eleven patients had successful treatment with intravenous antibiotics and either computerized tomographic scan guided percutaneous or open operative drainage . CONCLUSION: Onset of pyomyositis is usually insidious, with progression to purulent collections . Comorbid conditions likely predispose patients to pyomyositis and may contribute to delay in diagnosis and treatment . Increased awareness of this disease, especially in an immunosuppressed patient, should lead to earlier diagnosis and treatment with improved outcomes. Blood, 1997 Sep 1, 90(5), 1920 - 6 Human dendritic cells require exogenous interleukin-12-inducing factors to direct the development of naive T-helper cells toward the Th1 phenotype; Hilkens CM et al.; Dendritic cells (DC) are important initiators of specific primary immune responses because they are the only APC that can efficiently activate naive Th cells . DC have the capacity to produce interleukin-12 (IL-12), a cytokine that plays a pivotal role in the development of Th1-mediated cellular immune responses . The present study focuses on the conditions under which human DC produce bioactive IL-12 p70 and, consequently, direct the development of naive T helper (Th) cells toward the Th1 phenotype . Bacteria or bacterial compounds such as Staphylococcus aureus Cowan strain I (SAC) or lipopolysaccharide (LPS) induced substantial IL-12 levels in DC, which could be further upregulated by interferon-gamma (IFN-gamma), whereas induction of IL-12 production via CD40 ligation required IFN-gamma as an obligatory, complementary signal . Also, activated naive Th cells were poor inducers of IL-12 production, unless exogenous IFN-gamma was present, whereas activated memory Th cells were effective inducers of IL-12 production and did not require exogenous IFN-gamma . Next, the cytokine profiles of matured Th cells that were primed by DC under different conditions were examined . DC promoted the development of naive Th cells into memory Th0 cells that produced both the type 1 cytokine IFN-gamma and the type 2 cytokine IL-4 . In contrast, after activation with SAC, DC efficiently directed the development of Th1 cells through the release of IL-12 . An APC-independent Th cell maturation model, using either recombinant IL-12 or supernatants of SAC-activated DC and neutralizing anti-IL-12 antibodies, confirmed that DC-derived IL-12 was the major Th1 skewing factor . Together, these data indicate that the contact between DC and naive Th cells during the initiation of specific immune responses does not result in the efficient induction of IL-12 production and that, consequently, exogenous IL-12-inducing factors are required to promote primary Th1-mediated cellular immune responses. J Med Microbiol, 1997 Sep, 46(9), 779 - 83 Antibiotic-loaded hydroxyapatite blocks in the treatment of experimental osteomyelitis in rats; Itokazu M et al.; A novel drug delivery system for osteomyelitis was developed in which a porous hydroxyapatite block (HAB) is loaded with antibiotic by a centrifugation method . In this study, implantation of HABs loaded with the aminoglycoside antibiotic, arbekacin, were tested in established Staphylococcus aureus osteomyelitis in the proximal tibia of rats after debridement of the marrow cavity . The animals were observed for radiographic signs of infection and tissue was examined histologically . The infections were also evaluated by bone cultures . Bacterial counts were statistically lower in rats implanted with an antibiotic-loaded HAB than in those given a drug-free HAB . Radiographical and histological observations also showed beneficial effects of the antibiotic-loaded implant . The results suggest that the centrifugation method for loading HABs provides a simple drug delivery system . These antibiotic-loaded HABs may be useful for filling grafts in osteomyelitis. J Am Vet Med Assoc, 1997 Sep 1, 211(5), 590 - 2 Isolation of methicillin-resistant Staphylococcus aureus from a postoperative wound infection in a horse; Hartmann FA et al.; Methicillin-resistant Staphylococcus aureus (MRSA) was isolated from a postoperative wound infection in a horse . Methicillin-resistant S aureus infections in animals have been reported . In human beings, MRSA is an important cause of hospital-acquired (nosocomial) infections . Infections caused by MRSA respond poorly to beta-lactam treatment, and resistance of MRSA to multiple antimicrobials, including aminoglycosides, macrolides, clindamycin, and tetracyclines, is common . Identification of MRSA by routine susceptibility testing may be difficult; therefore, techniques for MRSA detection should be incorporated by clinicopathology laboratories . Because the number of hospital and community-acquired MRSA infections in human beings is increasing, it seems likely that MRSA infections in animals will also become more frequent. Am Surg, 1997 Sep, 63(9), 831 - 5 Absorbable, delayed-release antibiotic beads reduce surgical wound infection; Galandiuk S et al.; Absorbable, polyglycolic acid (PGA) beads were evaluated as a new vehicle for local antibiotic delivery . Incisions on the dorsa of guinea pigs were contaminated with 1 x 10(8) Escherichia coli and 1 x 10(8) Staphylococcus aureus . PGA beads containing either minocycline, amikacin, or no antibiotic (placebo) were placed into these wounds and compared to animals treated with systemic minocycline or amikacin alone . The diameter of wound erythema was measured daily for 7 days . Serial blood and wound quantitative cultures were obtained, and serum and wound antibiotic concentrations were determined . Both minocycline-PGA and amikacin-PGA-treated wounds exhibited less erythema than placebo-PGA wounds (P < 0.05) . All minocycline-PGA and amikacin-PGA-treated wounds healed primarily, whereas 67 per cent of placebo-PGA wounds developed purulence, dehisced, and healed secondarily . Local antibiotic delivery was more effective than systemic administration in reducing wound erythema and the number of bacteria in wound quantitative cultures . E . coli and S . aureus were quantitatively reduced (P < 0.05) in wounds of antibiotic PGA-treated animals compared to those in placebo-PGA-treated and systemic minocycline and systemic amikacin-treated animals . Measurable minocycline and amikacin concentrations were present in antibiotic-PGA-treated wounds through day 3, without detectable serum levels . Delayed-release, absorbable, antibiotic-containing PGA beads effectively prevent infection in contaminated wounds and have the advantage of not requiring vehicle removal. Biochemistry, 1997 Sep 9, 36(36), 10857 - 66 Probing the non-proline cis peptide bond in beta-lactamase from Staphylococcus aureus PC1 by the replacement Asn136 --> Ala; Banerjee S et al.; A non-proline cis peptide is present between Glu166 and Ile167 in the active site of beta-lactamase from Staphylococcus aureus PC1 . To examine the role of the interaction between the side chain of Asn136 and the main chain of Glu166, the site-directed mutant N136A was produced . The enzyme shows no measurable hydrolytic activity toward a variety of penicillins or cephalosporins except for the chromogenic cephalosporin, nitrocefin . For nitrocefin, the progress curve exhibits a fast burst with a stoichiometry of 1 mol of degraded substrate per mole of enzyme followed by a slow phase with a hydrolysis rate that is reduced by approximately 700-fold compared with that of the wild-type enzyme . Thus, the mutant enzyme is deacylation defective . Monitoring the hydrolysis of nitrocefin after preincubation with a number of beta-lactam compounds shows that cephalosporins form stable acyl complexes with the enzyme, whereas penicillins do not . The molecular weight of the mutant was determined by electrospray mass spectrometry, and the presence of the stable acyl enzyme adducts with cephaloridine and cefotaxime was confirmed by both electrospray and MALDI mass spectrometry . Therefore, in addition to impairing deacylation, the acylation machinery has been altered compared with the wild-type enzyme to act on cephalosporins and not on penicillins . Urea denaturation and thermal unfolding studies show that the N136A mutant enzyme is less stable than the wild-type enzyme . However, stability against chemical denaturation of the mutant enzyme is enhanced in the presence of cephaloridine beyond the stability of the wild-type protein . This is attributed to accumulation of favorable interactions between the cephaloridine and the protein, which play a role in the folded state and not in the unfolded state. J Bacteriol, 1997 Sep, 179(17), 5321 - 5 The femR315 gene from Staphylococcus aureus, the interruption of which results in reduced methicillin resistance, encodes a phosphoglucosamine mutase; Jolly L et al.; The femR315 gene was recently identified by Tn551 insertional mutagenesis as one of the new auxiliary genes, the alteration of which resulted in a drastically reduced methicillin resistance of the Staphylococcus aureus strain COL . femR315 (also known as femD) theoretically encoded a protein of 451 amino acids showing significant amino acid sequence homology with phosphoglucomutases and similar enzymes catalyzing the isomerization of hexoses and hexosamine phosphates (S . Wu, H . de Lencastre, A . Sali, and A . Tomasz, Microb . Drug Resist . 2:277-286, 1996) . We describe here the overproduction and purification of the FemR315 protein as well as its identification as the phosphoglucosamine mutase which catalyzes the formation of glucosamine-1-phosphate from glucosamine-6-phosphate, the first step in the reaction sequence leading to the essential peptidoglycan precursor UDP-N-acetylglucosamine . On the basis of these findings, we propose to change the names femR315 and femD to the functionally more appropriate name glmM. J Bacteriol, 1997 Sep, 179(17), 5259 - 63 Transcription of Staphylococcus aureus fibronectin binding protein genes is negatively regulated by agr and an agr-independent mechanism; Saravia-Otten P et al.; The production of cell surface proteins in Staphylococcus aureus is generally down-regulated in the postexponential growth phase by the global regulator agr . The effector of this regulation is the RNAIII molecule, which is encoded within the agr locus . RNAIII seems to regulate most target genes at the level of transcription, but it also has an effect on the translation of some genes . To study the role of agr on the expression of fibronectin binding proteins (FnBPs), we investigated the transcription and translation of fnb genes in agr mutant strain WA250 and its parent strain, 8325-4 . The results show that fnb genes are negatively regulated by agr and also by an agr-independent mechanism that restricts fnb mRNA synthesis to the early exponential phase of growth . Transcription and Western blot analysis of cell-associated FnBPs demonstrated that synthesis of both FnBPA and FnBPB in the wild-type and agr mutant strains took place preferentially during the first hour of growth and rapidly decreased after the second hour . We also confirmed previous results showing that the agr mutant strain has an increased capacity to bind fibronectin compared to its parent agr+ strain . However, while the concentrations of fnb mRNAs and proteins differed by a factor of 16 between the strains, the difference in fibronectin binding was only twofold, indicating that the binding of fibronectin to the bacteria is not proportional to the amount of FnBPs on their surface. Infect Immun, 1997 Sep, 65(9), 3889 - 95 Correlation of histopathologic and bacteriologic changes with cytokine expression in an experimental murine model of bacteremic Staphylococcus aureus infection; Yao L et al.; Staphylococcus aureus infections are often life threatening . Relatively little is known about the host response to these infections, in particular, the role played by cytokines . We established a mouse model of bacteremic S . aureus infection to correlate bacteriologic findings and pathologic changes with cytokine gene expression . Bacterial density in blood and tissue was highest at 1 h and minimal by 48 h . Despite the rapid clearance of bacteria, pathologic abnormalities and inflammatory cytokines were detected after clearance of the bacteria . The number of infiltrating inflammatory cells, as well as the size of inflammatory foci, increased with time . Interstitial accumulation of inflammatory cells and tissue damage, such as microabscesses, edema, and necrosis progressed following clearance of bacteria from the tissues . Levels of tumor necrosis factor and interleukin-1 protein in serum were detectable at 1 h and peaked at 4 h . Interleukin-6 protein expression showed different kinetics, with low levels detected at 1 h and increasing levels at 72 h postinfection . Tumor necrosis factor and the interleukins were expressed in inflammatory and noninflammatory cells in lung, liver, and heart tissues . Leukocytes in the infected tissues were highly reactive with antibodies to the three cytokines, suggesting that activated leukocytes are a major source of inflammatory cytokines after staphylococcal infection . Expression of interleukin-1 and interleukin-6 in tissue-specific cells and endothelial cells was also detected in infected tissues, indicating that cells other than leukocytes contribute to the elevated cytokine levels in this model . Once initiated, expression of inflammatory cytokines contributes to the pathogenesis of S . aureus disease. Infect Immun, 1997 Sep, 65(9), 3606 - 14 Analysis of expression of the alpha-toxin gene (hla) of Staphylococcus aureus by using a chromosomally encoded hla::lacZ gene fusion; Ohlsen K et al.; The staphylococcal alpha-toxin (Hla) is a major virulence factor contributing to Staphylococcus aureus pathogenesis . To elucidate the conditions influencing hla expression, the determinant was fused to lacZ, the reporter gene coding for beta-galactosidase . The hla::lacZ fusion was integrated into the chromosome of the wild-type S . aureus strain Wood 46, leading to the variant Wood 46-3 . Alpha-toxin expression was found to be dependent on temperature, showing a maximum at 42 degrees C . Furthermore, the indicator strain showed a growth phase-dependent hla regulation which was influenced by temperature . At 37 degrees C, induction of hla::lacZ expression occurred in the late exponential phase of growth, whereas at 42 degrees C, a strong induction was observed as early as the mid-exponential phase . These observations were verified by Northern blot analysis of hla mRNA and by Western blot (immunoblot) analysis of culture supernatants of strain Wood 46 . It was additionally found that the induction of hla transcription at 42 degrees C was not coupled with higher concentrations of agr RNAIII, the effector molecule of the global regulator agr . Furthermore, expression of the alpha-toxin was repressed at a high osmolarity . It was also shown that oxygen is essential for hla expression and that cultivation of the S . aureus strain Wood 46-3 on solid medium and in the presence of carbon dioxide stimulated hla transcriptional activity. J Immunol, 1997 Sep 1, 159(5), 2382 - 90 Superantigen activation of immune cells evokes epithelial (T84) transport and barrier abnormalities via IFN-gamma and TNF alpha: inhibition of increased permeability, but not diminished secretory responses by TGF-beta2; McKay DM et al.; Superantigens (SAgs) are extremely potent stimulants of T cell activity that have been implicated in the etiopathophysiology of inflammatory disease . Here, we tested the hypothesis that Staphylococcus aureus enterotoxin B (SEB), a model SAg, can alter epithelial transport and/or barrier functions via immune stimulation . Confluent monolayers of the human colonic T84 epithelial cell line, grown on filter supports, were cocultured with SEB +/- PBMC . Subsequently, T84 transport (consisting of baseline short-circuit current (Isc, indicates net ion transport) and secretory responses to carbachol and forskolin) and barrier functions (consisting of transepithelial resistance and fluxes of 3H-labeled mannitol and 51Cr-EDTA) were examined in Ussing chambers . T84 monolayers cocultured with SEB-activated PBMC displayed a time- and dose-dependent decrease in secretory responses to carbachol and forskolin and a significant increase in permeability . These dramatic changes in epithelial function were not due to reduced epithelial viability . Neutralizing Abs to IFN-gamma partially prevented the transport abnormalities, and Abs to TNF-alpha inhibited the increase in epithelial permeability . Abs to IL-1beta and IL-6 did not modulate the SEB-activated PBMC-induced T84 pathophysiology . Addition of TGF-beta2 to conditioned medium from SEB-activated PBMC partially inhibited the increase in T84 permeability but did not affect the transport abnormalities . We conclude that SAgs can elicit epithelial irregularities characteristic of enteric inflammation and that IFN-gamma and TNF-alpha are key mediators in this coculture model of epithelial dysfunction . Additionally, we would highlight the role that TGF-beta2 may play in preventing prolonged increases in epithelial permeability. J Immunol, 1997 Sep 1, 159(5), 2222 - 31 Developmental pathways of dendritic cells in vivo: distinct function, phenotype, and localization of dendritic cell subsets in FLT3 ligand-treated mice; Pulendran B et al.; We have recently shown that Flt3 ligand administration dramatically increases dendritic cell (DC) numbers in various mouse tissues . This has enabled the identification of distinct mature DC subpopulations . These have been designated: population C (CD11c(bright) CD11b(bright)), D (CD11c(bright) CD11b(dull)), and E (CD11c(bright) CD11b(negative)) This report demonstrates that the mature DC subsets (C, D, and E) from Flt3 ligand-treated mice differ with respect to phenotype, geographic localization, and function . The myeloid Ags CD11b, F4/80, and Ly-6C are predominantly expressed by population C, but not D or E . In addition, a subset of population C-type DC expresses 33D1 and CD4 . In contrast, DC within population D and E selectively express the lymphoid-related DC markers CD8alpha, DEC 205, CD1d, as well as CD23, elevated levels of CD117 (c-kit), CD24 (HSA), CD13, and CD54 . Immunohistology indicates that the different DC subsets reside in distinct microenvironments, with populations D and E residing in the T cell areas of the white pulp, while DC within population C localize in the marginal zones . These DC subpopulations showed different capacities to phagocytose FITC-zymosan and to secrete IL-12 upon stimulation with Staphylococcus aureus cowan I strain + IFN-gamma + granulocyte-macrophage-CSF . Population C-type DC were more phagocytic but secreted little inducible IL-12 while population D- and E-type DC showed poor phagocytic capacity and secreted considerably higher levels of IL-12 . These results underscore the importance of viewing DC development in vivo, as an interplay between distinct lineages and a maturational dependence on specific microenvironmental signals. J Immunol, 1997 Sep 1, 159(5), 2161 - 8 Interleukin-11 inhibits macrophage interleukin-12 production; Leng SX et al.; IL-12 is a heterodimeric cytokine produced by phagocytic and other cells with important physiologic and pathologic properties . Regulated IL-12 production is crucial for the generation of protective Th1 responses to infectious agents . In contrast, IL-12 excess contributes to the pathogenesis of a variety of autoimmune and inflammatory disorders . To further understand the processes regulating IL-12 production, we determined whether IL-11 regulated monocyte/macrophage production of this cytokine moiety . IL-11 did not alter the IL-12 (p70) production of unstimulated THP-1 monocytic cells or human blood monocytes . It did, however, inhibit, in a dose-dependent fashion, the IL-12 production of IFN-gamma plus Staphylococcus aureus Cowan strain 1-stimulated THP-1 cells and stimulated blood monocytes . This inhibition of IL-12 protein production was associated with a proportionate decrease in IL-12 p35 and p40 mRNA accumulation . Nuclear run-on assays revealed comparable decreases in IL-12 p35 and p40 gene transcription . IL-11 did not similarly regulate monocyte/macrophage production of IL-8 or macrophage inflammatory protein-1alpha (MIP-1alpha) and IL-6 did not similarly inhibit IL-12 elaboration . These studies demonstrate that IL-11 is a potent inhibitor of monocyte/macrophage IL-12 production and that this inhibitory effect is, at least in part, transcriptionally mediated . They also demonstrate that this inhibition is not the result of a generalized suppression of macrophage effector function and that the ability to inhibit monocyte/macrophage IL-12 production is not a generalized property of all IL-6-type cytokines. J Biol Chem, 1997 Aug 29, 272(35), 22285 - 92 Anchor structure of staphylococcal surface proteins . A branched peptide that links the carboxyl terminus of proteins to the cell wall; Ton-That H et al.; Surface proteins of Staphylococcus aureus are anchored to the cell wall by a mechanism requiring a COOH-terminal sorting signal . Previous work demonstrated that the sorting signal is cleaved at the conserved LPXTG motif and that the carboxyl of threonine (T) is linked to the staphylococcal cell wall . By employing different cell wall lytic enzymes, surface proteins were released from the staphylococcal peptidoglycan and their COOH-terminal anchor structure was revealed by a combination of mass spectrometry and chemical analysis . The results demonstrate that surface proteins are linked to a branched peptide (NH2-Ala-gamma-Gln-Lys-(NH2-Gly5)-Ala-COOH) by an amide bond between the carboxyl of threonine and the amino of the pentaglycine cross-bridge that is attached to the epsilon-amino of lysyl . This branched anchor peptide is amide-linked to the carboxyl of N-acetylmuramic acid, thereby tethering the COOH-terminal end of surface proteins to the staphylococcal peptidoglycan. MMWR Morb Mortal Wkly Rep, 1997 Aug 22, 46(33), 765 - 6 Staphylococcus aureus with reduced susceptibility to vancomycin--United States, 1997; Lif et al.; Institute of Medical Microbiology, University of Zurich, SwitzerlandThe formation of the Staphylococcus aureus peptidoglycan pentaglycine interpeptide chain needs FemA and FemB for the incorporation of glycines Gly2-Gly3, and Gly4-Gly5, respectively . The lysostaphin immunity factor Lif was able to complement FemB, as could be shown by serine incorporation and by an increase in lysostaphin resistance in the wild-type as well as in a femB mutant . However, Lif could not substitute for FemA in femA or in femAB-null mutants . Methicillin resistance, which is dependent on functional FemA and FemB, was not complemented by Lif, suggesting that serine-substituted side chains are a lesser substrate for penicillin-binding protein PBP2' in methicillin resistance. Thromb Res, 1997 Aug 15, 87(4), 387 - 95 A novel variant of staphylokinase gene from Staphylococcus aureus ATCC 29213; Kim SH et al.; The processes of hemostasis and thrombolysis are elegantly regulated in order to ensure normal functions of vascular system . A search for new plasminogen activators as thrombolytic agents has been carried out for the purpose of clinical applications to modulate thrombolytic processes . In the current work, several strains and clinical isolates of Staphylococcus aureus were screened for the fibrinolytic activity . The DNA sequences of staphylokinase gene in the strains expressing 15 kDa protein with staphylokinase activity were determined and subsequently compared with three known staphylokinase gene sequences . From the sequence comparison a new variant of staphylokinase gene has been identified in ATCC 29213 strain . The gene product needs to be further characterized and tested for the therapeutic potential. Ann Intern Med, 1997 Aug 15, 127(4), 257 - 66 Prevention of central venous catheter-related bloodstream infection by use of an antiseptic-impregnated catheter . A randomized, controlled trial; Maki DG et al.; BACKGROUND: Bloodstream infection related to short-term use of noncuffed central venous catheters is a common and serious problem . Technologic innovations to reduce the risk for these infections are needed . OBJECTIVE: To determine 1) the efficacy of a novel antiseptic catheter in preventing central venous catheter-related infection, 2) patient tolerance of this catheter, and 3) the sources of bloodstream infection originating from noncuffed, multilumen central venous catheters . DESIGN: Randomized, controlled clinical trial . SETTING: Medical-surgical intensive care unit of a 450-bed university hospital . PARTICIPANTS: 158 adults scheduled to receive a central venous catheter; 403 catheters were studied . INTERVENTION: Participants received either a standard triple-lumen polyurethane catheter or a catheter that was indistinguishable from the standard catheter and was impregnated with chlorhexidine and silver sulfadiazine . MEASUREMENTS: Catheters were studied for colonization and catheter-related bloodstream infection at removal; local and systemic effects of catheters were assessed . The origin of each catheter-associated bloodstream infection was sought by culturing all potential sources (skin, catheter segments, hubs, and infusate) and confirmed by restriction-fragment DNA subtyping . RESULTS: Antiseptic catheters were less likely to be colonized at removal than control catheters (13.5 compared with 24.1 colonized catheters per 100 catheters; relative risk, 0.56 {95% CI, 0.36 to 0.89}; P = 0.005) and were nearly fivefold less likely to produce bloodstream infection (1.0 compared with 4.7 infections per 100 catheters; 1.6 compared with 7.6 infections per 1000 catheter-days; relative risk, 0.21 {CI, 0.03 to 0.95}; P = 0.03) . In the control group, 8 catheter-related bloodstream infections were caused by Staphylococcus aureus, gram-negative bacilli, enterococci, or Candida species; no infections with these organisms occurred in the antiseptic catheter group (P = 0.003) . No adverse effects from the antiseptic catheter were seen, and none of the 122 isolates obtained from infected catheters in either group showed in vitro resistance to chlorhexidine-silver sulfadiazine . Cost-benefit analysis indicated that the antiseptic catheter should prove cost-beneficial if an institution's rate of catheter-related bacteremia with noncuffed central venous catheters is at least 3 infections per 1000 catheter-days) . CONCLUSIONS: The chlorhexidine-silver sulfadiazine catheter is well tolerated, reduces the incidence of catheter-related infection, extends the time that noncuffed central venous catheters can be safely left in place for the short term, and should allow cost savings. J Immunol, 1997 Aug 15, 159(4), 1909 - 16 Human endothelial cell activation and mediator release in response to the bacterial exotoxins Escherichia coli hemolysin and staphylococcal alpha-toxin; Grimminger F et al.; Escherichia coli hemolysin (HlyA) and Staphylococcus aureus alpha-toxin are membrane-perturbating bacterial exotoxins that have been implicated as significant virulence factors in human diseases . We investigated the capacity of these toxins to cause cell activation and mediator release in human endothelial cells, compared with the efficacies of thrombin and the Ca2+ ionophore A23187 . Concentration ranges tested were 1 to 1000 ng/ml (HlyA), 0.01 to 10 micro/ml (alpha-toxin), 0.01 to 10 U/ml (thrombin), and 0.01 to 10 microM (A23187) . All stimuli caused dose-dependent generation of platelet-activating factor, nitric oxide, and prostaglandin I2 . HlyA and thrombin effected time- and dose-dependent accumulation of large quantities of inositol phosphates, with maximum effects at 100 ng/ml and 1 U/ml, respectively . Corresponding time course and dose dependency were noted for HlyA-elicited diacylglycerol formation . In contrast, only the highest concentrations of alpha-toxin (10 microg/ml) and A23187 (10 microM) effected some moderate inositol phosphate accumulation, and this was suppressed in the presence of the platelet-activating factor antagonist WEB 2086 . Metabolic and secretory responses elicited by alpha-toxin were dependent on the presence of extracellular Ca2+ . We conclude that both HlyA and alpha-toxin are potent inductors of inflammatory and vasodilatory mediators in human endothelial cells . HlyA-elicited effects may proceed predominantly via activation of the phosphatidylinositol hydrolysis-related signal transduction pathway, whereas transmembrane Ca2+ flux appears to be the major event underlying the release of mediators in response to alpha-toxin . These toxin properties may contribute to vasoregulatory and inflammatory disturbances encountered in states of severe infection and sepsis. Biochemistry, 1997 Aug 12, 36(32), 9859 - 66 Structure and dynamics of pentaglycyl bridges in the cell walls of Staphylococcus aureus by 13C-15N REDOR NMR; Tong G et al.; Whole cells and cell-wall fractions of Staphylococcusaureus have been labeled by various combinations of {1-13C}glycine, {15N}glycine, L--6-13C-lysine, L--6-15N-lysine, D--1-13C-alanine, and D--15N-alanine . The resulting materials have been examined using 13C and 15N solid-state, magic-angle spinning NMR techniques including cross-polarization, double cross-polarization, and rotational-echo double resonance . The results of these measurements indicate that the peptidoglycan glycyl bridges are complete (five units long) and form cross-links between three-quarters of all peptide stems . The pentaglycyl bridges are immobilized in lyophilized cell-wall fractions in a compact conformation with inter-residue spacings comparable to those of an alpha helix . The bridges have a similar compact conformation in intact whole cells, regardless of whether the cells have been lyophilized or were hydrated and frozen at -10 degrees C . The bridges are also in a time-averaged compact conformation in whole cells at 0 degrees C but with sizable structural fluctuations associated with local mobility . A small fraction of bridges are in extended-chain conformations. Lancet, 1997 Aug 2, 350(9074), 323 - 5 Resistance to methicillin and other antibiotics in isolates of Staphylococcus aureus from blood and cerebrospinal fluid, England and Wales, 1989-95; Speller DC et al.; BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) strains are colonising hospital patients in most areas of England and Wales, UK . The extent to which they cause invasive infection can be gauged from their presence in isolates from blood or cerebrospinal fluid . METHODS: About 200 clinical laboratories reported the results of susceptibility testing of between 4501 and 6370 isolates of S aureus from blood or cerebrospinal fluid in each of the years 1989-95 . We assessed the rate of resistance to methicillin and other antibiotics for each of these years . FINDINGS: Resistance to methicillin was stable at about 1.5% of isolates during 1989-91, but increased thereafter to 13.2% in 1995 (p < 0.001) . At the same time there was a significant increase in the percentage of isolates resistant to erythromycin, clindamycin, ciprofloxacin, gentamicin, trimethoprim, and rifampicin (p < 0.001 for each)-resistance characteristics often seen in MRSA . Resistance to benzylpenicillin increased slightly but significantly (p < 0.001); resistance to fusidic acid was stable (p > 0.05); resistance to tetracycline decreased significantly (p < 0.001) . INTERPRETATION: Among cases of S aureus bacteraemia, the proportion due to MRSA has increased significantly . Bacteraemia due to MRSA has a poor prognosis, especially if not treated with suitable antibiotics . Therefore, these findings are important, especially for management of patients and the development of antibiotic policies. Immunopharmacology, 1997 Aug, 37(1), 15 - 23 Macrophage colony-stimulating factor (M-CSF) augments cytokine induction by lipopolysaccharide (LPS)-stimulation and by bacterial infections in mice; Hanamura T et al.; We studied the effects of M-CSF on cytokine induction in vivo by LPS or by bacterial infection by comparing between the serum cytokine levels of mice administered with and without M-CSF . M-CSF at 250 micrograms/kg/day for 3 days significantly augmented serum IL-6 level induced by a subsequent injection of 25 micrograms/kg of LPS . The augmented IL-6-induction was dose-dependent from 50 to 1250 micrograms/kg/day of M-CSF, and required 2- to 3-doses of M-CSF at 250 micrograms/kg/day . Mice primed with M-CSF induced IL-6 in response to a 5-fold lower dose of LPS, and also produced higher levels of IL-1 alpha, IL-10, GM-CSF, TNF-alpha, and IFN-gamma than control mice . The priming effect of M-CSF was transient and reversible, and elicited independently of T-cells . An injection with intact bacteria, such as Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus also induced IL-6 in normal mice, and M-CSF administration augmented the induction of these cytokines . These results showed that M-CSF positively regulates LPS-dependent and -independent cytokine induction, suggesting a defensive effect against infectious agents through enhanced cytokine production. Semin Vet Med Surg (Small Anim), 1997 Aug, 12(3), 186 - 92 Immunotherapy and cytokines; Van Kampen KR; Immunomodulation is now possible in veterinary medicine with the licensure of a number of biological products by the United States Department of Agriculture for veterinary use . These products activate primarily macrophages, induce the production of cytokines, and have various effects on the activity and proliferation of B and T lymphocytes . Those products most commonly used are inactivated whole bacteria of Propionibacterium acnes, cell wall fractions of nonpathogenic Mycobacterium spp, and the lysate derived from lysis of Staphylococcus aureus by a bacterial phage . All products have been licensed for use against specific diseases, but the literature includes studies for off-label usage . These immunomodulators are considered to be nonspecific stimulators of the immune system and may affect both humoral and cellular functions of immunity. J Appl Microbiol, 1997 Aug, 83(2), 155 - 65 Plasmids and bacterial resistance to biocides; Russell AD; Plasmid-encoded bacterial resistance to antibiotics and to anions and cation (including important mercurial and silver compounds) has been widely studied . Plasmid-mediated resistance to organic cationic agents which are important biocides has been described for chlorhexidine and quaternary ammonium compounds (and also for the less important acridine, diamidines and ethidium bromide) in antibiotic-resistant Staphylococcus aureus and Staph . epidermidis strains . Plasmids may also encode reduced biocide susceptibility of Gram-negative bacteria, but intrinsic resistance is likely to be of greater significance . Antibiotic resistance and biocide resistance may be linked but this is not always found clinically. J R Coll Surg Edinb, 1997 Aug, 42(4), 259 - 61 An analysis of the factors contributing to mortality rates in burns patients treated at Mpilo Central Hospital, Zimbabwe; Muguti GI et al.; We present a retrospective analysis of 49 patients (61% males and 39% females) with burns who died at Mpilo Central Hospital between January 1990 and December 1993 . Of the patients, 61% (30/49) were in the paediatric age group, with 55% (27/49) under 2 years of age . Most burns occurred at home (79%) and 17% of the burns occurred at the workplace . The commonest burning agents were hot water (39.5%) and open fires (39.5%) . The surface area of burns ranged from 10 to 88% with a mean of 35% . Deep partial thickness and full thickness burns accounted for 52% of cases . All the patients required active resuscitation with intravenous fluids . A total of 35 organisms were isolated on 18 pus swabs . The most commonly isolated organisms were Staphylococcus aureus (43%) and Pseudomonas (23%) . The main factors contributing to death were septicaemia (n = 15), pneumonia (n = 10) and acute renal failure (n = 7) . The majority of patients (65%) died within 10 days, 61% of whom were children . The average time to death was 14 days (range 1-64 days) . It is clear that some patients with severe burns will die regardless of how well they are managed . The key to successful management of those patients who should survive lies in early presentation and active resuscitation, prevention and control of infective complications and adequate nutritional support. Am J Infect Control, 1997 Aug, 25(4), 312 - 21 Surveillance of colonization and infection with Staphylococcus aureus susceptible or resistant to methicillin in a community skilled-nursing facility; Lee YL et al.; BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) is an important nosocomial pathogen in acute care hospitals and long-term care facilities . Few studies have been reported in private skilled nursing facilities (SNFs) not experiencing outbreaks of infections caused by MRSA . METHODS: From a 149-bed SNF with no outbreaks, we report a 1-year prospective surveillance study of S . aureus colonization and infection, with focus on S . aureus phenotypes, both methicillin susceptible (MS) and methicillin resistant (MR) . Nasal and stool or rectal screening cultures were done on admission, and all patients underwent screening on at least a quarterly basis for 1 year . RESULTS: Overall, 35% of patients were colonized at least once with S . aureus, (72% MS, 25% MR, and 3% mixed phenotypes), 94% of the MRSA were ciprofloxacin resistant . Nasal colonization with any S . aureus was more frequent, but 13% of patients had positive results only in rectal specimens . Twenty-one percent of the newly admitted and 15% of continuing patients acquired colonization during their stay in the SNE Colonization was transient or persistent, persisted longer in the nares compared with colonization in rectal specimens, and was more stable for methicillin-susceptible S . aureus . Nine percent of patients had development of infection with S . aureus . There was no indication that MRSA colonization led to more infections than methicillin-susceptible S . aureus . Of the 13 infected patients in whom cultures had previously been obtained, seven (54%) had been colonized by the same phenotype strains . CONCLUSIONS: In this private SNF, endemic S . aureus infections occur at a low frequency, reflecting a moderate level of colonization with S . aureus . However, a trend showing gradual increases in frequencies of colonization and infection is of concern and suggests that in this SNF, future intervention could become warranted. Am J Infect Control, 1997 Aug, 25(4), 303 - 11 Applying the Centers for Disease Control and Prevention and National Nosocomial Surveillance system methods in Brazilian hospitals; Starling CE et al.; BACKGROUND: Nosocomial infection is an important public health problem in Brazil . The better to understand and address this problem, we began using the National Nosocomial Infection Surveillance (NNIS) system in five Brazilian hospitals in 1991 . METHODS: Data were collected prospectively according to the NNIS protocol, by using nosocomial infection definitions from the Centers for Disease Control and Prevention . RESULTS: From January 1991 to June 1995, the overall nosocomial infection rate was 5.1% or 9.7 nosocomial infections/1000 patient-days . From the detailed epidemiologic information obtained by using the NNIS methods, interventions were designed and implemented that have reduced specific nosocomial infection rates . For example, the incidence of infection caused by methicillin-resistant Staphylococcus aureus was reduced from 0.61 infections/1000 patient-days in 1991 to 0.05 infections/1000 patient-days in 1996 (p < 0.01) . The surgical site infection rate after cesarean section was reduced from 11.6% in 1993 to 5.9% in 1996 (p < 0.05) . Cost savings from a program to optimize the use of antimicrobial agents in one hospital was more than $1.8 million over a 45-month period . CONCLUSION: The NNIS method was applicable in a wide variety of hospitals, even those with little or no experience with nosocomial infection surveillance . By using this method, we defined the detailed epidemiology of nosocomial infection and implemented interventions that have significantly reduced nosocomial infection rates while achieving substantial cost savings. Clin Orthop, 1997 Aug, (341), 206 - 14 Treatment of osteomyelitis with a biodegradable antibiotic implant; Calhoun JH et al.; A biodegradable antibiotic implant was developed and evaluated in a localized osteomyelitic rabbit model . The biodegradable antibiotic implant was made of polylactic acid and poly(DL-lactide):co-glycolide combined with vancomycin . Localized rabbit tibial osteomyelitis was developed with Staphylococcus aureus . Infected rabbits were divided into eight groups, depending on treatment with or without debridement, systemic antibiotics, or biodegradable beads . After 4 weeks of therapy, the radiographs were obtained of the involved bones, which also were cultured for concentrations of Staphylococcus aureus per gram of bone . Treatment with antibiotic containing polylactic acid and poly(DL-lactide):co-glycolide beads, with and without systemic vancomycin, resulted in bone colony forming unit levels of 10(2.93) and 10(2.84) colony forming units per gram bone, respectively . These bacterial concentrations were approximately 100 times lower than those observed for all other treatment groups . A biodegradable antibiotic bead may provide extended bactericidal concentrations of antibiotics for the time needed to completely treat the particular orthopaedic infection and does not require the surgery needed to remove the polymethylmethacrylate beads. Thromb Haemost, 1997 Aug, 78(2), 902 - 9 Effect of a new monoclonal anti-glycoprotein IX antibody, KMP-9, on high shear-induced platelet aggregation; Miyake T et al.; Human platelet glycoprotein Ib/IX complex acts as a receptor for von Willebrand factor . It is widely accepted that glycoprotein Ib is the essential receptor component, but the role of glycoprotein IX is still unclear . We produced a new monoclonal anti-glycoprotein IX antibody (KMP-9) by the hybridoma technique using platelets from a patient with Glanzmann's thrombasthenia . The epitope of KMP-9 was localized to the C-terminal 8 kD fragment of glycoprotein IX using ELISA analysis of polyethylene-pin-synthesized peptides, as well as Western blot analysis of platelets after digestion with N-glycosidase and Staphylococcus aureus V8 protease . KMP-9 partially inhibited high shear stress-induced platelet aggregation, but had no effect on aggregation induced by ristocetin or low shear stress . Its inhibitory effect on high shear stress-induced aggregation was weaker than that of anti-glycoprotein Ib or anti-glycoprotein IIb/IIIa monoclonal antibodies . A 21-mer synthetic peptide (glycoprotein IX L110-G130) inhibited the binding of KMP-9 to platelets . It also competively inhibited the suppression of high shear stress-induced platelet aggregation by KMP-9, but had no direct effect on this aggregation . KMP-9 may be useful to clarify the physiological role of GPIX. Leukemia, 1997 Aug, 11(8), 1298 - 304 Interleukin-15 + thioredoxin induce DNA synthesis in B-chronic lymphocytic leukemia cells but not in normal B cells; Soderberg O et al.; We have previously shown that Staphylococcus aureus Cowan strain 1 particles (SAC) + thioredoxin (Trx) + IL-2 may induce B-chronic lymphocytic leukemia (B-CLL) cells to proliferate . In this paper we have examined IL-15, which has activities similar to IL-2, for its ability to stimulate B-CLL cells and compared its activity with that of IL-2 . We found that B-CLL cells could be induced to DNA synthesis upon treatment with IL-15 + Trx . The presence of Trx was essential for the IL-15-induced DNA synthesis . This contrasts to the effect of IL-15 + Trx on normal CD5+ and CD5- B cells, where IL-15 + Trx alone only induced limited DNA synthesis . IL-15 was as effective in the induction of DNA synthesis in B-CLL cells as IL-2, but about 100-fold less potent with an EC50 of 200 ng/ml . In addition we found that the IL-15 + Trx-induced proliferation was inhibited by CD40 stimulation . We conclude that IL-15 together with a proper costimulus can induce B-CLL cells to proliferate in vitro. J Hosp Infect, 1997 Aug, 36(4), 291 - 303 Simultaneous persistence of methicillin-resistant and methicillin-susceptible clones of Staphylococcus aureus in a neonatal ward of a Warsaw hospital; Trzcinski K et al.; Fifty-seven methicillin-resistant Staphylococcus aureus (MRSA) isolates from babies (N = 31), carriers amongst health care workers (N = 16; 10% of all staff members) and the environment (N = 10); 39 MSSA isolates, from babies (N = 18), health care workers (N = 5) and environment (N = 16) were analysed . The strains were from the neonatal ward of a teaching hospital in Warsaw and were collected over a period of 16 months (1993/1994) . The isolates were characterized by phage-typing, arbitrary-primed polymerase chain reaction (AP PCR), DNA repeat polymorphism within the protein A gene and the resistance pattern to antimicrobial agents . The presence of the mecA gene was determined by PCR . MRSA were classified as heterogeneously resistant to methicillin, susceptible to other antimicrobial agents and, except for three isolates, appeared to be genotypically almost identical . The first example of mupirocin resistant MRSA in Poland was documented . Amongst MSSA isolates, increased variability was seen, however, the persistence of one predominate clone of MSSA was shown . In this particular hospital environment, several different strains of both MRSA and MSSA were capable of maintaining persistent colonization. J Biomed Mater Res, 1997 Aug, 36(2), 152 - 62 Quantitative comparison of shear-dependent Staphylococcus aureus adhesion to three polyurethane ionomer analogs with distinct surface properties; Dickinson RB et al.; Bacterial adhesion is a central step in infection on biomaterial surfaces; however, the relation between biomaterial surface properties and adhesion remains poorly understood . To quantitatively determine the relationship among polyurethane surface properties, protein coating, and adhesion, we have compared attachment and detachment kinetics of Staphylococcus aureus on three different novel polyurethanes with different protein coatings . Rate constants for attachment or detachment were measured as a function of shear rate in a well-defined laminar flow field . The tested polyurethanes included a relatively hydrophobic-base polyether urethane and hydrophilic anionomer and cationomer analogs of the base material . Materials were tested bare, or coated with human fibrinogen, plasma, or albumin . The results suggest that the presence of fibrinogen or plasma greatly enhance the attachment rate constants and decrease the detachment rate constants on all materials . The most extreme differences among the different materials were observed on the bare materials, with the base polyurethane being most resistant to both attachment and detachment . However, except for a reduced attachment rate constant on the plasma-coated sulfonated polyurethane, few differences in the rate constants were observed among protein-coated materials, suggesting the primary role of surface properties is masked by the presence of the adsorbed protein layer. J Med Chem, 1997 Aug 1, 40(16), 2563 - 70 The chemistry of pseudomonic acid . 18 . Heterocyclic replacement of the alpha,beta-unsaturated ester: synthesis, molecular modeling, and antibacterial activity; Brown P et al.; The electronic requirements around the C1-C3 region of pseudomonic acid analogues were investigated . Synthetic routes were developed to access a range of compounds where the alpha, beta-unsaturated ester moiety had been replaced by a 5-membered ring heterocycle . The inhibition of isoleucyl tRNA synthetase from Staphylococcus aureus NCTC 6571 was determined as was the minimum inhibitory concentration (MIC) of the test compounds against that organism . Compounds possessing a region of electrostatic potential corresponding to that of the carbonyl group in the alpha, beta-unsaturated ester, and a low-energy unoccupied molecular orbital in the region corresponding to the double bond, were found to have IC50 values of 0.7-5.3 ng mL-1 . However the MIC values of these compounds were in the range 2.0-8.0 micrograms mL-1, reflecting their poorer penetration into the bacterial cell. Am J Med Sci, 1997 Aug, 314(2), 118 - 21 Pityriasis rubra pilaris: an unusual cutaneous complication of AIDS; Bonomo RA et al.; Pityriasis rubra pilaris is an uncommon hyperkeratotic, papulosquamous disorder that has been reported in patients infected by HIV . We recount a case of pityriasis rubra pilaris in an HIV-seropositive man . A 36-year-old man with a history of ulcerative colitis and recurrent otitis externa had diffuse psoriaform erythroderma . He was treated initially with methotrexate and isoretinoin without clinical improvement . Skin examination showed large, erythematous, orange, scaly patches on the upper extremities and thickening of the nail beds . The palms and soles were hyperkeratotic . Skin biopsy revealed changes that were consistent with pityriasis rubra pilaris . Six months before the onset of symptoms, results of an enzyme-linked immunosorbent assay (ELISA) and Western Blot assay for HIV were negative . Six months after symptoms, results of repeat enzyme-linked immunosorbent assay and Western blots for HIV were positive (CD4+ T-cell count = 200 cells/ mm3) . Clinical course had been complicated by episodes of Staphylococcus aureus bacteremia, mucocutaneous candidiasis, and development of localized squamous cell carcinoma of the skin . The increased severity of pityriasis rubra pilaris should prompt clinicians to consider coinfection with HIV in patients who have disease that is refractory to treatment . Clinicians also should remain vigilant for the development of squamous cell carcino