Staphylococcus

J Infect Dis, 1994 Feb, 169(2), 324 - 9
Opsonic antibodies to Staphylococcus epidermidis: in vitro and in vivo studies using human intravenous immune globulin; Fischer GW et al.; Staphylococcus epidermidis is a major cause of nosocomial infections, including sepsis in premature infants . Intravenous immune globulin (IVIG) has been used to prevent neonatal sepsis, but efficacy has varied in different clinical trials . The role of IgG antibody in immunity to S . epidermidis was studied using an opsonophagocytic assay and a lipid-emulsion-induced lethal model of neonatal S . epidermidis sepsis . Opsonic antibody to S . epidermidis varied between IVIG preparations and between lots: Lots with > or = 90% opsonic activity promoted bacterial clearance from blood and significantly enhanced survival when compared with lots with < or = 50% opsonic activity . Absorption of IVIG with S . epidermidis removed in vitro opsonic and in vivo protective activity . These studies suggest that opsonic antibody may play an important role in S . epidermidis immunity in immunocompromised patients, such as premature infants . Standard IVIG, however, may not provide therapy effective in preventing S . epidermidis infections, as many IVIG lots contain insufficient levels of opsonic S . epidermidis antibody.

Immunobiology, 1994 Feb, 190(1-2), 116 - 26
Activation of human T cells by the superantigen Staphylococcus enterotoxin B: analysis on a cellular level; Dannecker G et al.; Superantigens interact with and activate a sizeable fraction of T cells characterized by expression of specific V beta gene segments of their antigen receptor . The massive activation of T cells in an organism is considered responsible for clinical symptoms associated with superantigen-producing bacteria . Here we studied the in vitro activation of human T cells by the superantigen Staphylococcus Enterotoxin B on a cell by cell basis . Superantigen-reactive T cells were stained with a V beta 12-specific monoclonal antibody and analyzed in a cytofluorograph . Blast formation of SEB-reactive T cells occurs within 12 h and reaches a plateau after 24 h . Double-staining of V beta 12+ T cells with antibodies against different T cell activation or adhesion surface molecules revealed a time-dependent differential upregulation for CD2, CD11 = LFA-1, CD25, CD28, CD69, and HLA-DR . The expression of CD3, CD4 and CD5 was not influenced by the superantigen . The rapid phenotypic changes of superantigen reactive T cells in terms of marker expression and cell size could provide early tools in diagnosing diseases caused by superantigens.

Eur J Clin Microbiol Infect Dis, 1994 Feb, 13(2), 111 - 7
Modification of central venous catheter polymers to prevent in vitro microbial colonisation; Tebbs SE et al.; The efficacy of an antimicrobial catheter for the prevention of bacterial colonisation was investigated . The catheter was hydrophilic coated (Hydrocath) and impregnated with the quaternary ammonium antimicrobial agent, benzalkonium chloride (BZC) . Microbial colonisation of this central venous catheter was compared to that of polyurethane catheters with or without a hydrophilic coating . Adherence of five strains of Staphylococcus epidermidis to the three catheter types was determined with a microbial colonisation model . Adherence of three strains of Staphylococcus epidermidis to Hydrocath catheters was significantly reduced in comparison to polyurethane catheters (p < 0.01) . BZC-impregnated Hydrocath catheters prevented bacterial colonisation of both the internal and external catheter surfaces (p < 0.01) . These results were confirmed by scanning electron microscopy . The findings demonstrate that hydrophilic-coated Hydrocath catheters can inhibit bacterial adherence in vitro . Bacterial colonisation was further restricted by the addition of BZC to these coated catheters.

Pain, 1994 Feb, 56(2), 243 - 4
Staphylococcal meningitis following Synchromed intrathecal pump implant: a case report; Bennett MI et al.; Staphylococcal meningitis associated with implantation of an intrathecal drug pump for spasticity was successfully treated by intrathecal vancomycin delivered by the same pump . This produced high CSF antibiotic levels, and the pump and catheter system did not have to be removed . We are unable to identify a similar case reported in the literature to date.

Br J Pharmacol, 1994 Feb, 111(2), 525 - 32
Importance of inositol (1,4,5)-trisphosphate, intracellular Ca2+ release and myofilament Ca2+ sensitization in 5-hydroxytryptamine-evoked contraction of rabbit mesenteric artery; Seager JM et al.; 1 . Small strips from third-order branches of rabbit mesenteric artery (approximately 150-200 microM wide) contracted in response to noradrenaline (10 microM) or 5-hydroxytryptamine (5-HT; 10 microM) in oxygenated Krebs solution containing 2.5 mM Ca2+ . In a Ca(2+)-free mock intracellular solution (0 Ca2+ plus 0.2 mM EGTA), noradrenaline (10 microM) and caffeine (10 mM) induced only a single, transient contraction in artery strips, while 5-HT (10 microM) failed to induce any response . 2 . In strips of mesenteric artery which had been permeabilized with Staphylococcus alpha-toxin and bathed in Ca(2+)-free mock intracellular solution, noradrenaline (10 microM), caffeine (10 mM) and D-myo-inositol (1,4,5)-trisphosphate (IP3, 100 microM), but not 5-HT (10 or 100 microM) induced a transient contraction . In contrast to the non-permeabilized strips, contractions to noradrenaline, caffeine and IP3 were restored by prior incubation (10 min) in solution containing 0.08 microM Ca2+ . The contractions to noradrenaline and IP3 in permeabilized muscle strips required the presence of 100 microM guanosine 5'-triphosphate (GTP), although in the absence of Ca2+ . GTP alone did not induce contraction . 3 . Exposure of permeabilized mesenteric artery strips to IP3 significantly reduced the subsequent contractile responses to caffeine . Contractile responses to caffeine and IP3 were abolished by the Ca(2+)-ATPase inhibitor, thapsigargin (1 microM) . 4 . Ca2+ (0.1-10 microM) induced concentration-dependent contraction in permeabilized artery strips . In strips which were submaximally contracted with 0.5 microM Ca2+/100 microM GTP, the subsequent addition of 5-HT (10 microM) stimulated further contraction . The protein kinase C inhibitor, H-7 (1 microM) abolished the 5-HT/GTP-induced contraction, but did not alter the contraction to Ca2+.(ABSTRACT TRUNCATED AT 250 WORDS)

Arq Bras Cardiol, 1994 Feb, 62(2), 91 - 4
{Bacteremia induced by labor . Is prophylaxis for infective endocarditis necessary?}; Tiossi CL et al.; PURPOSE--To characterize the occurrence of bacteremia during delivery and to verify the necessity of prophylaxis against infective endocarditis . METHODS--The authors collected hemoculture of 100 women, 15,30 and 45 minutes after delivery . The data were collected from May 1992 until May 1993 . The positive hemocultures were followed by antibiogram . RESULTS--Seven hemocultures were positive: six for Staphylococcus, one for Candida sp, Penicilium sp, Clandosporum sp and Aspergillus sp that were found in association . Four patients had prematures amniorrhexis, longer than 6 hours before delivery (p < 0.05) . Six patients had labor longer than 6 hours after admission (p < 0.05) . The authors did not observe differences related to vaginal delivery with or without forceps or cesarean section . The samples were all sensible to cefalotin at the antibiogram . CONCLUSION--Labor and delivery is a high risk procedure for bacteremia and so for ineffective endocarditis in susceptible patients . The statistical analysis recognize as risk factors labor longer than 6 hours inside the hospital and premature amniorrhexis . We propose the use of intravenous cefalotin 1g 60 minutes before expulsion and repeated 6 and 12 hours later.

Eur J Biochem, 1994 Feb 1, 219(3), 821 - 7
Identification of a glutamate residue at the active site of xylanase A from Schizophyllum commune; Bray MR et al.; The xylanase A (endo-1,4-beta-D-xylan xylanhydrolase) of the basidiomycete Schizophyllum commune was treated with the powerful carboxylate-modifying reagent 1-(4-azonia-4,4-dimethyl-pentyl)-3-ethylcarbodiimide iodide (EAC) in the presence of substrate . This treatment was followed by complete inactivation of the enzyme with {14c}EAC after the removal of excess reagent and protecting ligand . The inactivated enzyme was digested with endoproteinase Arg-C or trypsin, and peptides were separated and purified using reverse-phase high-performance liquid chromatography . Following sub-digestion of individual radioactive peptides with staphylococcal V8 protease and endoproteinase Lys-C, amino acid composition analysis and sequencing analysis revealed that the {14C}EAC label was bound exclusively to Glu87 . Comparison of the primary sequences of related xylanase with that of xylanase A revealed that Glu87 is a highly conserved residue . Based on this similarity and the mechanism of carbodiimide action, Glu87 is proposed to act as the nucleophile in the catalytic mechanism of xylanase A . The possible environment of the putative catalytic glutamate residue was explored using hydrophobic-cluster analysis and secondary-structure prediction based on the primary sequence of xylanase.

J Acquir Immune Defic Syndr, 1994 Feb, 7(2), 124 - 8
Proliferative response of CD4+ and CD8+ T cell subsets from Hispanics with HIV+ and AIDS: the superantigen hypothesis; Eylar EH et al.; It has been hypothesized that the progressive deletion of CD4+ T cells in the course of infection due to human immunodeficiency virus (HIV) may be mediated in part by interaction with a superantigen inherent in an HIV protein . Consequently, selective loss of CD4+ cells with a T cell receptor V beta-chain capable of interaction with superantigen would produce a CD4+ population less or totally unresponsive to superantigen such as staphylococcal enterotoxins B and A (SEB and SEA respectively), but not to other mitogens such as concanavalin A, anti-CD3 (OKT3), or pokeweed mitogen . We tested this hypothesis by comparing the proliferative response of SEB and SEA with the other mitogens for 25 controls, 20 HIV+, and 15 donors with acquired immune deficiency syndrome (AIDS) . We found that peripheral blood mononuclear cells, as well as the CD4+ and CD8+ subsets from both HIV+ and AIDS sources, the degree of suppression of mitogenesis for SEB and SEA was approximately equal to or less than that of the other mitogens . Moreover, suppression of HIV+ CD4+ and CD8+ T cell responses to SEB and SEA was equal (26%) . If HIV superantigens exist, our data suggest that they are not responsible for the selective depletion of the CD4+ T cell subset as evaluated by SEB and SEA specificity.

J Immunol, 1994 Feb 1, 152(3), 1154 - 62
Stimulator cell type influences the response of T cells to staphylococcal enterotoxins; Yagi J et al.; Responses to the superantigen Mls are characterized by proliferation of a significant percentage of T cells expressing receptors encoded by one or a few V beta gene segments . Apparently similar responses are elicited by the staphylococcal enterotoxins (SEs) and other bacterial superantigens . We have observed that T cells can be stimulated by the bacterial superantigen SEs presented by either spleen cells or fibroblasts transfected with the appropriate MHC class II genes . However, the results in this study showed that T cells required more than 100-fold higher concentrations of SEA in the presence of L cell transfectants than spleen APC, although T cell responses to SEB and several other toxins presented by the two types of APC were equivalent . Thus, L cell transfectants have a selective defect in presenting SEA . These data suggest that fibroblasts lack a component required by SEA to stimulate certain T cells, and lead us to propose an alternative model for bacterial superantigen mitogenesis in which the superantigen binds to and modifies the behavior of an endogenous co-ligand.

Lett Appl Microbiol, 1994 Feb, 18(2), 86 - 9
RAPD typing of clinical isolates of Staphylococcus haemolyticus; Young KA et al.; The randomly amplified polymorphic DNA (RAPD) assay was used to generate DNA fingerprints from clinical isolates of Staphylococcus haemolyticus isolated from patients treated with continuous ambulatory peritoneal dialysis and previously subjected to a combination of typing methods . The RAPD profiles generated with one of six randomly designed 10-mer primers allowed visual discrimination of strains . Good correlation with the original typing scheme was achieved but RAPD typing allowed discrimination of strains previously indistinguishable.

Proc Natl Acad Sci U S A, 1994 Jan 18, 91(2), 449 - 53
Staphylococcal nuclease folding intermediate characterized by hydrogen exchange and NMR spectroscopy; Jacobs MD et al.; Pulsed hydrogen-deuterium exchange during refolding was used to probe the protection of backbone amide hydrogens from solvent exchange of the staphylococcal nuclease Pro117-->Gly variant . The extent of exchange for 39 residues was determined by two-dimensional proton NMR after refolding for 5 ms to 10 s . Three kinetic phases are inferred . Modest protection of amides in the early refolding intermediate composed of two beta-sheets formed by local sequence interactions was observed after a 5-ms refolding period . Protection factors were determined by varying the high pH labeling pulse after refolding for 100 ms . The intermediate state has modest, yet significant, protection for residues in the beta-sheets (protection factors of 10-60) and almost no protection in the alpha-helices (protection factors of < 10) . The pattern of labeling is consistent with a role for beta-turns and beta-hairpins in the formation of the early intermediate.

J Mol Biol, 1994 Jan 7, 235(1), 27 - 32
Evidence for strained interactions between side-chains and the polypeptide backbone; Stites WE et al.; In most proteins, a small but significant fraction of residues adopt phi,psi angles that generate unfavorable steric interactions between side-chain atoms and the peptide backbone . For the small protein staphylococcal nuclease, the X-ray structure reveals that 18 of 133 residues occupy unusual and, presumably, energetically unfavorable backbone conformations . To quantify the amount of strain energy generated by these local interactions, we have analyzed the changes in stability that accompany replacement of the wild-type side-chain with glycine, a residue that can access a much larger set of phi,psi angles without energy penalty . To correct for the many other sources of stability loss that might accompany this mutation, the glycine mutant was compared to an alanine mutant at the same position and the resulting free energy difference delta delta GG-->A was then compared to the average delta delta GG-->A at all other, unstrained positions in the nuclease occupied by similar amino acid types . In addition, potential steric clashes were introduced by substituting alanine at each of six positions occupied in the wild-type by glycine with phi,psi angles that are unfavorable for all other residue types . The data suggest that residues with phi,psi angles outside the preferred alpha-helical and beta-sheet regions represent sites of local strain energy that lower the stability of the native state by 1 to 2 kcal/mol and, in some cases, as much as 3 to 4 kcal/mol . Given that 10 to 20% of residues in globular proteins adopt phi,psi angles outside the preferred alpha-helical and beta-sheet regions, this implies that there is on the order of 20 kcal/mol of strain energy in a protein of 100 residues that may be relieved by appropriate mutations.

Nature, 1994 Jan 6, 367(6458), 94 - 7
Structural basis of superantigen action inferred from crystal structure of toxic-shock syndrome toxin-1; Acharya KR et al.; Superantigens stimulate T cells bearing particular T-cell receptor V beta sequences, so they are extremely potent polyclonal T-cell mitogens . T-cell activation is preceded by binding of superantigens to class II major histocompatibility complex (MHC) molecules . To further the structural characterization of these interactions, the crystal structure of a toxin associated with toxic-shock syndrome, TSST-1, which is a microbial superantigen, has been determined at 2.5 A resolution . The N- and C-terminal domains of the structure both contain regions involved in MHC class II association; the C-terminal domain is also implicated in binding the T-cell receptor . Despite low sequence conservation, the TSST-1 topology is similar to the structure reported for the superantigen staphylococcal enterotoxin B4 . But TSST-1 lacks several of the structural features highlighted as central to superantigen activity in the staphylococcal enterotoxin B and we therefore reappraise the structural basis of superantigen action.

J Invest Dermatol, 1994 Jan, 102(1), 31 - 8
Superantigenic staphylococcal exotoxins induce T-cell proliferation in the presence of Langerhans cells or class II-bearing keratinocytes and stimulate keratinocytes to produce T-cell-activating cytokines; Tokura Y et al.; Several staphylococcal toxins are among a growing number of immunostimulatory molecules called "superantigens" because of their ability, when presented by appropriate major histocompatibility complex class II+ accessory cells, to activate essentially all T cells bearing particular T-cell receptor V beta gene segments . We have examined the ability of murine epidermal Langerhans cells and/or keratinocytes to act as accessory cells in the T-cell response to the superantigens staphylococcal enterotoxin B and exfoliative toxin, also known as epidermolysin . Purified murine splenic T cells were stimulated with staphylococcal enterotoxin B or exfoliative toxin in the presence of Langerhans cells--enriched epidermal cells from normal mice or epidermal cells isolated from mice pretreated with recombinant interferon-gamma, a procedure that induces the expression of major histocompatibility complex class II molecules on keratinocytes . The data show that both Langerhans cells and class II-bearing keratinocytes can act as accessory cells in the T-cell response to staphylococcal enterotoxin B and exfoliative toxin . We also observed that both human and murine keratinocytes cultured in the presence of staphylococcal enterotoxin B or exfoliative toxin produce increased amounts of cytokine(s) capable of stimulating thymocytes and D10 cells, and that this toxin activity is independent of the level of expression of class II on keratinocytes . Studies by enzyme-linked immunosorbent assay showed that staphylococcal enterotoxin B stimulates keratinocytes to produce tumor necrosis factor-alpha but not interleukin-1, suggesting tumor necrosis factor-alpha and perhaps other cytokines are responsible for the T-cell proliferative activity . These results demonstrate that two distinct epidermal constituents (i.e . Langerhans cells and keratinocytes) can serve as accessory cells in the responses of T cells to superantigenic bacterial toxins . It is possible that such toxins contribute to the pathogenesis of a variety of skin diseases by either locally activating T cells bearing particular V beta genes and/or enhancing keratinocyte production of immunomodulatory cytokines.

J Exp Med, 1994 Jan 1, 179(1), 63 - 9
Rat T cell responses to superantigens . II . Allelic differences in V beta 8.2 and V beta 8.5 beta chains determine responsiveness to staphylococcal enterotoxin B and mouse mammary tumor virus-encoded products; Gold DP et al.; The previous paper in this series demonstrates that rat T cells developing de novo in the presence of mouse mammary tumor virus (Mtv) antigens in rat-->severe combined immunodeficiency (SCID) mouse xenochimeras display a distinct pattern of V beta-restricted deletion; this deletion pattern is remarkably similar to that occurring during thymic development of mouse T cells in Mtv+ strains . In addition, T cells developing in the absence of Mtv antigens in these rat-->mouse xenochimeras are tolerant of host antigens, but show strong primary proliferative responses in cultures stimulated with Mtv-7+ (Mlsa) mouse cells; like the mouse, these rat T cell responses are dominated by V beta 6 and V beta 8 T cells . Here, we continue analysis of rat T cell responses to superantigens; we show that T cells from Lewis and Fischer 344 rats expressing V beta 8.2 display an important all-or-nothing difference in their responses to Mtv-7 superantigens . This all-or-none strain difference in the response to Mtv-7 applies also to the response by V beta 8.2 and V beta 8.5 T cells to the soluble superantigen staphylococcal enterotoxin B . Because these two rat strains express different alleles of these two V beta 8 family members, this finding identifies additional, hitherto unreported residues of the T cell receptor beta chain important in T cell responses to superantigens.

Pharmacol Res, 1994 Jan-Feb, 29(1), 59 - 64
Antimicrobial activity of 5-substituted-3-amino-1,2,4-triazoles; Serra C et al.; Some dyes derived from 3-amino-5-(ortho, meta, and para-pyridyl)-1,2,4-triazoles were tested for antimicrobial activity . 13 compounds showed anti-staphylococcal activity and one had anti-candida activity . Some substances had antimicrobial activity only after light irradiation.

Intensive Care Med, 1994, 20(2), 142 - 4
Swan-Ganz catheter-related pulmonary valve infective endocarditis: a case report; Bernardin G et al.; We report the case of a 29-year-old man with decompensated alcoholic cardiomyopathy who developed a Staphylococcal pulmonic valve infective endocarditis during hemodynamic monitoring, as a consequence of catheter-related bacteremia . As experimentally demonstrated, the damaging role of the pulmonary artery catheter on the endocardial surface plays a major role in the pathogenesis of related right-sided infective endocarditis . Occurrence of bacteremia in a catheterized patient should be considered as a high risk situation, and righ-heart infective endocarditis must be suspected whenever patient presents fever or bacteremia without obvious site of infection . Doppler echocardiography is the reference diagnosis procedure.

J Clin Apheresis, 1994, 9(1), 31 - 2
Protein A immunoadsorption treatment in hematology: an overview; Howe RB et al.; Staphylococcal protein A efficiently binds immunoglobulins and circulating immune complexes (CIC) and provides an effective medium to remove immunoglobulins and CICs from plasma while sparing albumin and most coagulation proteins . Although it activates the complement system its clinical use abrogates the need for plasma expanders necessitated by plasma exchange . Despite anecdotal reports of utility in several hematologic syndromes, publications of clinical trials are available only for autoimmune thrombocytopenic purpura (AITP) and refractoriness to platelet transfusions (RFT) associated with alloimmunization . In the former situation Snyder et al . (Blood 79:2237-2245, 1992) reported on 72 patients with AITP all of whom had failed at least two previous therapies including splenectomy in 68% . Forty-six percent achieved improved platelet counts following treatment . The response was durable (8-26 mo) in all but 10% . Spleen-intact patients could not be differentiated from those who had been splenectomized . Both responders and nonresponders showed significant decreases in CIC and platelet-directed immunoglobulin (PDIG), but responders achieved near-normal levels . The beneficial response of these factors, particularly in spleen-intact patients, warrants a prospective study . In our studies at the University of Minnesota twelve patients with thrombocytopenia secondary to bone marrow failure who were refractory to platelet transfusion were treated with protein A immunoadsorption . Ten had demonstrable antiplatelet Abs (Anti-HLA, HPA, ABO) . Seven of 12 demonstrated improved platelet counts and post-transfusion corrected count increments after treatment . This was associated with decreased platelet utilization and clinical bleeding . A prospective controlled clinical trial is justified.

Drug Chem Toxicol, 1994, 17(1), 1 - 14
Use of staphylococcal enterotoxin A-induced lymphoproliferation and interleukin 2 production as indicators of immunotoxicity; Reid LL et al.; Suppression of mitogen-induced splenocyte lymphoproliferation and interleukin 2 (IL-2) production can be used as indicators of immunotoxicity . Staphylococcal enterotoxin A (SEA) is both a potent mitogen and the most potent in vitro inducer of IL-2 production that has been described . An in vitro system was used to measure impairment of SEA-induced lymphoproliferation and IL-2 production using splenocytes from female C57BL/6 mice dosed with either cyclosporin A (30 mg/kg/day, 14 days), benzene (220, 440, or 880 mg/kg/day, 14 days), or vehicle . Splenocytes were stimulated with either concanavalin A (con A) or SEA . Benzene- and cyclosporin A-treated mice demonstrated significant decreases in splenocyte proliferation . IL-2 production was determined by incubating splenocyte culture supernatants with IL-2 dependent cytotoxic T-cells (CTLL-2), pulsing with 3H-thymidine, and determining amount of incorporated label . Cell proliferation and IL-2 production were inhibited by both benzene and cyclosporin A, effects more clearly demonstrated using SEA than con A . SEA was a superior mitogen compared to con A in the assays evaluated here.

Proteins, 1994 Jan, 18(1), 68 - 80
Magnetic resonance studies of the binding of oligonucleotide substrates to mutants of staphylococcal nuclease; Chuang WJ et al.; By a combination of NMR docking and model building, the substrate binding site on staphylococcal nuclease was found to accommodate a trinucleotide and to consist of three subsites, each interacting with a single nucleotidyl unit of DNA . Binding of the essential Ca2+ activator and substrate cleavage occur between subsites 1 and 2 . Hence, catalytically productive binding would span subsites 1 and 2 while nonproductive binding would span subsites 2 and 3 . Lys-49 is near subsite 1, and Lys-84 and Tyr-115 interact with substrates at subsite 3 {Weber, D.J., Gittis, A.G., Mullen, G.P., Abeygunawardana, C., Lattman, E.E., Mildvan, A.S . Proteins 13:275-287, 1992} . The proposed locations of these subsites were independently tested by the effects of the K49A, K84A, and Y115A mutations of staphylococcal nuclease on the binding of Mn2+, Ca2+, and the dinucleotide and trinucleotide substrates, 5'-pdTdA, dTdA, and dTdAdG . These three mutants have previously been shown to be fully active and to have CD and 2D NMR spectra very similar to those of the wild-type enzyme (Chuang, W.-J., Weber, D.J., Gittis, A.G., Mildvan, A.S . Proteins 17:36-48, 1993) . All three mutant enzymes and their pdTdA and dTdA complexes (but not their dTdAdG complex) bind Mn2+ and Ca2+ more weakly than the wild-type enzyme by factors ranging from 2 to 11 . The presence of a terminal phosphate as in 5'-pdTdA raises the affinity of the substrate for staphylococcal nuclease and its three mutants by two orders of magnitude and for the corresponding enzyme-metal complexes by three to four orders of magnitude, suggesting that the terminal phosphate is coordinated by the enzyme-bound divalent cation . Such complexation would result in the nonproductive binding of 5'-pdTdA at subsites 2 and 3 . Accordingly, the K84A and Y115A mutations significantly weaken the binding of 5'-pdTdA and its metal to staphylococcal nuclease by factors of 2.2 to 37.8, while the K49A mutation has much smaller or no effect . Such nonproductive binding explains the low activity of staphylococcal nuclease with small substrates, especially those with a terminal phosphate . Similarly, the K84A and Y115A mutations weaken the binding of dTdA and its metal complexes to the enzyme by factors of 3.4 to 13.1 while the K49A mutation has smaller effects indicating significant nonproductive binding of dTdA . The trinucleotide dTdAdG binds more tightly to wild-type and mutant staphylococcal nuclease and to its metal complexes than does the dinucleotide dTdA by factors of 2.4 to 12.2, reflecting the occupancy of an additional subsite.(ABSTRACT TRUNCATED AT 400 WORDS)

Fetal Diagn Ther, 1994 Jan-Feb, 9(1), 35 - 7
Risk estimation of intraamniotic infection development after serial amniocentesis; Terzic MM et al.; Microbial invasion and growth in amniotic fluid play an important role in infectious perinatal morbidity and mortality . In order to determine the influence of amniocentesis (ACT) on intra-amniotic infection development, we performed a study of 239 complete microbiological examinations of amniotic fluid specimens obtained by serial interventions . In 1 case (0.42%), during the second procedure, Staphylococcus epidermidis was discovered . Neither spontaneous abortion nor preterm labor were provoked by the procedure . We can conclude that ACT has been confirmed as a safe and successful intrauterine intervention if it is made in a proper manner.

Biophys J, 1994 Jan, 66(1), 40 - 5
Comparison of kinetics of formation of helices and hydrophobic core during the folding of staphylococcal nuclease from acid; Chen HM et al.; Our previous kinetic study of the acid and base-induced folding/unfolding transitions of staphylococcal nuclease (SNase) has monitored Trp-140 fluorescence . Trp-140 is located near the flexible COOH terminus and whether or not its fluorescence reflects the overall conformation of the protein has yet to be established . Here we show that the fluorescence intensity of Try-140 correlated closely with the thermal stability (i.e., the calorimetric enthalpy, delta Hcal, of unfolding) of the protein in the pH range 7 to 2.5, confirming that it is a good measure of the overall protein structure . Circular dichroism (CD) at 222 nm, which reflects the helical content of the protein molecule, was used to follow the same folding/unfolding transition in order to compare kinetics of the helix formation and of the appearance of the hydrophobic core . In addition to the three kinetic phases reported earlier with the fluorescence detection, there were a rapid reaction (completed within the 25 ms mixing time of the instrument), which comprised 15% of the signal, and a very slow reaction (time constant > 300 s), which comprised 19% of the signal . With the fluorescence detection for the folding from acid, only 5% of the signal occurred in the rapid phase and there was no reaction slower than 300 s . By comparing kinetics of folding at pH 7 by the CD and fluorescence detection methods, we concluded that: (a) Roughly 15% of the helix content of SNase accumulated before significant changes in the hydrophobic environment (< 5%) of Trp-140 could be detected.(ABSTRACT TRUNCATED AT 250 WORDS)

J Pediatr Orthop, 1994 Jan-Feb, 14(1), 45 - 7
Radiodense lines and subclinical infection in pediatric hip surgery; Verska J et al.; A subtle radiolucency with surrounding sclerosis was seen in 14 of 129 hip implant removals in 90 children . Five of these implants were cultured, and all five grew Staphylococcus epidermidis . The other nine were not cultured . None of the 14 had sequela . These radiographic findings should prompt suspicion of infection even in the absence of clinical or laboratory findings; they should also prompt hardware removal.

Ann Chir Gynaecol Suppl, 1994, 208, 84 - 7
Mastitis today: incidence, prevention and treatment; Jonsson S et al.; The study concerned 664 women of South-West Finland, and they were studied 5-12 weeks after delivery . The total frequency of mastitis in this population was much higher than generally reported in literature, 24% as opposed to 3% . The frequency of mastitis was similar among nulli- and multiparous women . The diagnosis was based on the judgement of midwives of physicians . If a multiparous woman has had mastitis during a previous puerperium, the probability of mastitis during a subsequent puerperium is threefold . The type of skin, its reaction of the sun, allergies, rashes, getting cold and oxytocin medication during delivery did nto affect the incidence of mastitis . Mothers under 21 and over 35 years of age had a decreased incidence (P = 0.034) of mastitis . If the women had sore nipples, the frequency increased (P = 0.003) . Prophylaxis, by means of physical training, neither decreased nor increased the frequency of puerperal mastitis . The treatment advised by midwives and physicians was primarily conservative, but 38% received antibiotics; some of the antibiotics were not effective against staphylococcal infection.

Microbiol Immunol, 1994, 38(3), 209 - 15
Stimulation of the synthesis of histamine and putrescine in mice by a peptidoglycan of gram-positive bacteria; Ando T et al.; To clarify the base of in vivo biological activities of peptidoglycans of Gram-positive bacteria, the effects of a polysaccharide peptide of Staphylococcus epidermidis peptidoglycan (SEPS) on the synthesis of histamine and putrescine in BALB/c mice were examined and compared with those of a lipopolysaccharide (LPS or endotoxin) of Gram-negative bacteria . Within a few hours after its injection into BALB/c mice, SEPS induced histidine decarboxylase (HDC), the enzyme forming histamine, in the liver, lung, spleen and bone marrow, and ornithine decarboxylase (ODC), the enzyme forming putrescine, in the tissues except for the lung . SEPS induced HDC activity even in mast cell-deficient mice and in nude mice . These effects of SEPS were essentially the same as those of LPS . However, the dosage of SEPS capable of inducing HDC and ODC was much higher (100 to 1,000 times) than that of LPS . We have reported that C3H/HeN mice are resistant to SEPS in producing acute arthritis, and their productions of IL-1 and prostaglandin E2 are less than BALB/c mice sensitive to producing acute arthritis . In the present study, it was also found that C3H/HeN mice were markedly resistant to SEPS in inducing HDC activity.

Pneumonol Alergol Pol, 1994, 62(3-4), 194 - 8
{Recurrent infections of the respiratory tract and staphylococcal pneumonia with septic shock and total respiratory failure in a patient with histiocytosis X}; Wawrzynska L et al.; Disseminated pulmonary infiltrates, cutaneous lesions and diabetes insipidus in a female patients with a history of recurrent pneumothorax and persistent respiratory tract infections suggested the diagnosis of histiocytosis X . The pathological examination of a biopsy lung tissue specimen confirmed that diagnosis . In the course of treatment many dangerous complications were observed . The intensive therapy including artificial ventilation (24 days) was fully effective and settle the beneficial clinical outcome.

Zhongguo Ji Sheng Chong Xue Yu Ji Sheng Chong Bing Za Zhi, 1994, 12(1), 20 - 2
{Molecular recognition between GlcNAc and Plasmodium falciparum merozoites}; Zhu K et al.; In this study p-aminophenyl-2-acetamido-2-deoxy-beta-D-glucopyranoside was bound covalently to bovine serum albumin (BSA) to form neoglycoprotein (GlcNAc-BSA) . The antigenicity of BSA and the pyranose structure of the sugar was preserved . By using the neoglycoprotein antibody against BSA and staphylococcal protein A-gold (SPA-gold), Plasmodium falciparum FCC-1/HN merozoites were immunolabeled . The labelled sample was observed under transmission electron microscope (TEM) . The TEM pictures showed that colloidal gold pellets were distributed all over the merozoite surface . This is the first report on the direct experimental evidence of molecular recognition between GlcNAc-BSA (or GlcNAc) and Plasmodium falciparum merozoites . But free GlcNAc or even GlcN can inhibit the immunolabeleation . The results support the hypothesis that, besides N-acetylneuraminic acid, GlcNAc is involved as another recognized site on GPA for Plasmodium falciparum . Thus we further confirmed that N-acetyl of GlcNAc is not necessary for the recognition.

Arch Microbiol, 1994, 161(5), 384 - 92
Threonine is present instead of cysteine at the active site of urease from Staphylococcus xylosus; Jose J et al.; DNA sequence analysis of the structural urease genes from Staphylococcus xylosus revealed that three enzyme subunits are encoded in the order of 11,000, 15,400 and 61,000 (mol . mass), which correspond to the single polypeptide chain of jack bean urease (90,800) . Comparing the deduced amino acid sequence of S . xylosus urease with the amino acid sequence of jack bean urease an overall portion of 56% identical residues was found . For S . xylosus urease a subunit structure of (alpha beta gamma)4 was proposed, based on the comparison of the deduced amino acid content of the enzyme subunits with the total amino acid content of the purified enzyme . The staphylococcal enzyme contained no cysteine, as deduced from DNA sequence and confirmed by the determination of the total amino acid content in the purified enzyme . Instead of cysteine, known to be catalytically essential in the plant enzyme, and conserved among all bacterial ureases analyzed so far, threonine was found in S . xylosus . This amino acid-exchange was located within a highly conserved domain of 17 amino acids, supposed to be part of the active site . Sequence analysis of the respective region of Staphylococcus saprophyticus urease showed that it also contains threonine instead of cysteine . In contrast to jack bean urease S . xylosus urease was not affected by the SH-group inhibitor dipyridyl disulfide but was completely inhibited by the serine protease inhibitor phenylmethanesulfonyl fluoride . The presented results indicate that in these staphylococcal strains urea hydrolysis might function in a manner similar to the peptide bond cleavage by chymotrypsin.

Probl Tuberk, 1994, (2), 53 - 5
{Thyroid gland function and intrapulmonary temperature in tuberculosis}; Kirchik OP et al.; The experiment on 140 albino mice examined the relationship between the pulmonary thermogenesis and the functional activity of the hypophyseal-thyroid system at different stages of pulmonary tuberculous inflammation development, during Staphylococcus-induced pneumonia, aseptic inflammation in lung tissue . Deep abnormalities of the heat-generating function of the lung were revealed just at the early periods of specific inflammation . The degree of hypothermal reactions of lung tissue correlated with the inhibition of hypophyseal-thyroidal function at all developmental stages of a tuberculous process . The changes were rather pronounced, stable and phasic . Spontaneous regression of the tuberculous process was not accompanied by recovery in the activity of the hypophyseal-thyroidal system, despite the fact that there was a clear-cut trend to normalization of pulmonary thermogenesis.

Gerontology, 1994, 40(1), 1 - 7
Differential action of staphylococcal alpha-toxin on young and old erythrocytes; Kantor L et al.; Band 3 of rabbit erythrocytes is a binding site for staphylococcal alpha-toxin . Young erythrocytes have a functionally intact band 3 of 100 kD that is hydrolysed as the cells age into a 35-kD fragment . Consequently, aging of erythrocytes renders them more resistant to the action of the toxin . Thus the age of a blood sample will reduce the sensitivity of the hemolytic assay and contribute to the variation of this assay.

Klin Lab Diagn, 1994, (1), 44 - 6
{Differentiation between resident and transitory staphylococcal microflora in bacterial carrier state}; Bukharin OV et al.; The authors have identified the range of informative biologic characteristics fit for differentiation between resident and transitory staphylococcal microflora in bacterial carriers . Among the detected differences is, first of all, staphylococcal capacity to inactivate antiinfectious resistance factors, this capacity represented mainly in the group of resident strains . Based on the findings the authors have developed a table of diagnostic coefficients making use of probability statistics methods; use of this table helps identify 76.6-82.5% of the examined cultures.

Intensive Care Med, 1994, 20(3), 187 - 92
Prevention of gram negative nosocomial bronchopneumonia by intratracheal colistin in critically ill patients . Histologic and bacteriologic study; Rouby JJ et al.; OBJECTIVE: To evaluate the efficiency of intratracheal colistin in preventing nosocomial bronchopneumonia (BPN) in the critically ill . DESIGN: Study evaluating the clinical incidence of nosocomial BPN in 2 groups of critically ill patients who receive or did not receive intratracheal colistin . BPN was assessed clinically in survivors and histologically in non-survivors . SETTING: A 14-bed surgical intensive care unit . PATIENTS: 598 consecutive critically ill patients were studied during a prospective non-randomized study over a 40-month period . INTERVENTIONS: 251 patients--31 non-survivors and 220 survivors--did not receive intratracheal colistin and 347-42 non-survivors and 305 survivors--received intratracheal colistin for a 2-week period (1,600,000 units per 24 h) . MEASUREMENTS AND RESULTS: The incidence of nosocomial BPN was evaluated clinically in survivors, using repeated protected minibronchoalveolar lavages, and histologically in non-survivors via an immediate postmortem pneumonectomy (histologic and semi-quantitative bacteriologic analysis of one lung) . The clinical incidence of nosocomial BPN was of 37% in coli (-) survivors and of 27% in coli (+) survivors (p < 0.01) . This result was histologically confirmed in non-survivors, where the incidence of histologic BPN was of 61% in coli (-) patients and of 36% in coli (+) patients (p < 0.001) . Emergence of BPN due to colistin-resistant micro-organisms was not observed . Because colistin was successful in preventing Gram-negative BPN and did not change the absolute number of Gram-positive BPN, the proportion of BPN caused by staphylococcus species was higher in group coli (+) patients (33% vs 16%) . Mortality was not significantly influenced by the administration of colistin . CONCLUSION: This study suggests that the administration of intratracheal colistin during a 2-week period significantly reduces the incidence of Gram-negative BPN without creating an increasing number of BPN due to colistin-resistant micro-organisms.

Adv Perit Dial, 1994, 10, 241 - 4
In vitro compatibility of a 1.1% amino acid containing peritoneal dialysis fluid with phagocyte function; Brulez HF et al.; The effects of a recently introduced peritoneal dialysis fluid (PDF) containing amino acids (AA) were compared with those of a glucose-based PDF (G-PDF) on viability and function of donor granulocytes (PMNs) in vitro . After 30 min incubation in the PDF, viability, assessed by trypan blue exclusion, and phagocytosis capacity (PC), tested in two assays using a fluorescein and a 3H-labeled Staphylococcus epidermidis strain, were significantly better in AA-PDF than in G-PDF (p < 0.002 in the 3H-assay) . Bactericidal activity was not different in the PDFs . If pH of G-PDF was adjusted from 5.2 to neutral, differences in PC disappeared . In AA-PDF, PMN chemiluminescence (CL) response was significantly higher than in G-PDF (p < 0.003) . At neutral pH, however, PMNs showed a significant stronger CL-response in 1.36% G-PDF than in AA-PDF (p < 0.05) . These data suggest that this AA-PDF has little detrimental effect on phagocyte viability and function . The improved compatibility over G-PDF in in vitro tests seems to be pH dependent . The reduced chemiluminescence response compared to 1.36% G-PDF with neutral pH is possibly due to quenching by (one of the) amino acids and osmolarity.

Chin J Biotechnol, 1994, 10(1), 25 - 32
High-level expression of staphylococcal nuclease A in Escherichia coli; Jing G et al.; The staphylococcal nuclease A gene has been successfully cloned and overexpressed in E . coli under the transcriptional control of the bacteriophage lambda PRPL promoters regulated by the temperature sensitive repressors . The SDS-PAGE analysis demonstrates that the nuclease A is produced to the extent of as much as 60% of the total cellular protein . The N-terminal analysis of the nuclease A shows that the amino terminal formyl methionine residue of the enzyme is precisely processed . The recombinant nuclease A with full activity is finally obtained after appropriate solubilization--denaturation and renaturation treatment . The conformational identity of the renatured nuclease A in different conditions is also studied by using hydrophobic interaction chromatography on a phenyl-superose HR5/5 column.

Vasa, 1994, 23(3), 268 - 73
{Fresh homologous arterial transplant as aorto-iliac-femoral vascular replacement in prosthesis infection}; Kniemeyer HW et al.; A patient with late graft infection in the groin following aorto-bifemoral-Dacron-bypass and recurrent infection of extra-anatomic bypasses is presented . Despite the evidence or graft infection (by preoperative imaging studies and intraoperative perigraft purulence) cultures did not identify the infective organism . Retrospectively a graft infection with Staphylococcus epidermidis is supposed as the most likely cause . A graft replacement with freshly harvested, not cryopreserved arterial homograft was performed . The perfusion of the extremities was excellent, the wounds healed perfectly . In special indications freshly harvested cadaveric arterial homografts are an acceptable substitute for infected aorto-femoral grafts.

Vox Sang, 1994, 67(1), 32 - 5
Microbiologic contamination of peripheral blood stem cell autografts; Schwella N et al.; We have determined the incidence and clinical significance of positive microbiologic cultures in a series of 290 peripheral blood stem cell concentrates in 95 patients undergoing multiple apheresis procedures for autologous stem cell rescue . Specimens for bacterial cultures were obtained after processing of the autografts just prior to freezing . The incidence of microbial contamination was 4.5% (n = 13) . The predominant pathogenic microorganism cultured was coagulase-negative Staphylococcus (n = 11) . From 8 patients with contaminated leukapheresis products 6 underwent autologous stem cell transplantation . Five patients received 1-5 culture-positive stem cell concentrates without serious sequelae, whereas the sixth patient was autografted with noncontaminated leukapheresis products, 1 concentrate contaminated with Aspergillus fumigatus being not reinfused . No microorganism present in the stem cell autograft was recovered in vivo in the posttransplantation period, although fever as a sign of infection occurred in all but 1 patient . Peripheral blood stem cell collection and ex vivo processing for cryopreservation may result in microbiologic contamination . However, our data show that infusion of contaminated stem cell autografts does not play a significant role as a source for infections in the clinical setting of autologous stem cell rescue.

Nephrol Dial Transplant, 1994, 9(7), 785 - 90
In-vitro biocompatibility of alternative CAPD fluids; comparison of bicarbonate-buffered and glucose-polymer-based solutions; Jorres A et al.; Evidence is accumulating that conventional dialysis fluids for CAPD are incompatible with peritoneal host defence . We therefore investigated the effect of alternative CAPD fluids on mononuclear leukocyte (PBMC) viability and cytokine production in vitro . Fluids tested were bicarbonate-buffered solutions containing 1.5% or 4.25% glucose, 7.5% glucose polymer dialysis fluid (GPDF), and conventional 1.5% glucose fluid (G1.5%) . PBMC were stimulated (2 h, 37 degrees C) in the different test fluids with a clinical isolate of Staphylococcus epidermidis or Escherichia coli lipopolysaccharide . The cytokines TNF alpha and IL-6 in PBMC supernatants were measured by specific enzyme immunoassays . Induction of cytokine messenger RNA was evaluated by reverse transcription-polymerase chain reaction . Conventional G1.5% (pH 5.5) inhibited cytokine release from activated PBMC by > 95%, whereas cell responses in low-glucose bicarbonate fluid were not significantly reduced . In contrast, high-glucose bicarbonate fluid exerted > 80% inhibition despite its neutral pH . GPDF was inhibitory at its initial low pH, whereas cytokine release was restored following pH neutralization . Cytokine mRNA expression was suppressed by conventional G1.5% fluid and by high-glucose bicarbonate fluid . These data indicate that pH neutralization leads to a substantial improvement of dialysis fluid biocompatibility; however, hyperosmolality and/or high glucose content inhibit cell responsiveness even at normal pH . Replacement of glucose by glucose polymer might prove beneficial provided that the initial low pH is neutralized.

Microbiol Immunol, 1994, 38(7), 527 - 34
Genotyping of Staphylococcus epidermidis by small-fragment restriction endonuclease analysis and pulsed-field gel electrophoresis of genomic restriction fragments; Haertl R et al.; Small-fragment restriction endonuclease analysis (SF-REA) was established as a typing tool for Staphylococcus epidermidis . A total of 60 isolates comprising 48 epidemiologically nonrelated strains and 12 putatively linked isolates from 7 patients in 2 wards were analyzed . Nonrelated isolates were characterized by unique fingerprints when DNA was cleaved with EcoRI or ClaI, electrophoretically separated in a polyacrylamide gel, and silver stained . Three blood culture isolates from one patient in an intensive care unit, 4 isolates obtained from a child over a span of 2 weeks, and 5 isolates from 5 newborns in the same ward were grouped into 3 DNA pattern types, indicating identity of sequential isolates from 2 patients and nosocomial transmission of one Staphylococcus epidermidis strain between 5 babies . Results from pulsed-field gel electrophoresis of SmaI and SacII DNA digests and conventional marker systems such as antibiogram and plasmid profile were in accordance with these interpretations, whereas slight variation was observed in the biotypes of several strains . From the results of this study, we conclude that SF-REA is a precise and efficient method for the genotypic characterization of Staphylococcus epidermidis strains that can be used as a rapid and reliable typing tool.

Med Dosw Mikrobiol, 1994, 46(1-2 Suppl), 51 - 7
{Autovaccine used in comprehensive treatment of staphylococcal inflammation of bone}; Boloczko S et al.; We have presented theoretical assumptions and experimental applications of autovaccines in comprehensive treatment of chronic staphylococcal inflammation of bones . The authors discuss the material about 44 patients including 27 of those with post-traumatic inflammation of bones in whom the treatment concerning surgical processing with inflow drainage, antibiotic therapy and fragment of fractured bone stabilization was given using the staphylococcal autovaccine . The successful treatment results which we obtained in 28 patients suggest to include the autovaccine in comprehensive treatment of chronic staphylococcal inflammation of bones . It especially refers to post-traumatic inflammation of bones and infected false joints which still remains a difficult therapeutic problem.

Chirality, 1994, 6(6), 496 - 509
Evaluation of the macrocyclic antibiotic vancomycin as a chiral selector for capillary electrophoresis; Armstrong DW et al.; Vancomycin is one of a family of related macrocyclic glycopeptide antibiotics that were discovered by scientists at the Eli Lilly Company in the 1950s . It has been used to treat severe staphylococcal infections, particularly when bacterial resistance to other antibiotics has developed . Vancomycin is a naturally occurring chiral compound and has a number of stereogenic centers . Furthermore, it contains a variety of functionalities that are known to be useful for enantioselective interactions (e.g., hydrogen bonding groups, hydrophobic pockets, aromatic groups, amide linkages, etc.) . The physiochemical properties of vancomycin, including its stability in solution, are discussed as they pertain to capillary electrophoresis . Over 100 racemates were resolved including many nonsteroidal antiinflammatory drugs, antineoplastic compounds and N-derivatized amino acids . Many of these compounds had very high resolution factors . Optimization and the effect of different experimental parameters on the enantioselective separations are discussed.

Zentralbl Gynakol, 1994, 116(8), 488 - 91
{Puerperal and non-puerperal mastitis}; Krause A et al.; Report about 82 women with inflammatory breast diseases, who were hospitalized during january 1988 and december 1993 . 37 women had a puerperal mastitis, 39 women a non-puerperal mastitis and 6 had perimamillary abscesses . In 35 (42.7%) of the 82 patients abscesses occurred . The different etiology and bacteriology as well as resulting treatment guidelines are discussed . In the treatment of puerperal mastitis, staphylococcus effective penicillins keep the first place . The therapy of non-puerperal mastitis consists in prolactin inhibiting drugs and broad spectrum antibiotics . In abscesses and fistulas surgical treatment is necessary, the same in recurrences . If the process is suspicious for breast cancer diagnostic excision is to perform.

Arthritis Rheum, 1994 Jan, 37(1), 113 - 24
T cell influence on superantigen-induced arthritis in MRL-lpr/lpr mice; Mountz JD et al.; OBJECTIVE . To define the influence of the T cell receptor (TCR) and the lpr autoimmune gene on the induction and progression of superantigen-induced arthritis in V beta 8 transgenic MRL-lpr/lpr mice . METHODS . The time to onset and the extent of synovial hyperplasia after the induction of arthritis by intraarticular injection of staphylococcal enterotoxin B (SEB) were compared in mice having T cells that bear the V beta 8 transgene alone (V beta 8 TCR transgenic MRL-+/+), the lpr gene without the V beta 8 gene (nontransgenic MRL-lpr/lpr), both the V beta 8 gene and the lpr gene (V beta 8 transgenic MRL-lpr/lpr), or neither gene (nontransgenic MRL-+/+) . Synovial hyperplasia was compared in SEB-injected V beta 8 transgenic MRL-lpr/lpr mice after treatment with cyclosporin A (CSA), anti-V beta 8 and anti-CD4 monoclonal antibodies, and in V beta 8 transgenic MRL-lpr/lpr mice after injection of a non-V beta 8-reactive superantigen, staphylococcal enterotoxin A (SEA) . RESULTS . At day 30, increased synovial cells were observed in all SEB-treated mice, but the increase was greatest in the V beta 8 transgenic MRL-lpr/lpr mice . T cell involvement was indicated by the inability of either heat-denatured SEB or SEA to induce severe arthritis, the reduction in the severity of the arthritis on systemic treatment with CSA or anti-V beta 8, and the correlation of synovial hyperplasia with in vitro SEB reactivity of T cells . CONCLUSION . These observations suggest that superantigens can induce chronic arthritis and that the induction and progression of the arthritis requires an underlying T cell defect in anergy induction in addition to exposure to the superantigen.

Int J Clin Pharmacol Res, 1994, 14(3), 111 - 4
Immune response in patients with intra-abdominal infections treated with carbapenems; Brismar B et al.; The immune responses against isolated microorganisms in patients with intraabdominal infections treated with meropenem or imipenem/cilastatin were investigated . Fifty-nine patients received meropenem 500 mg t.i.d . intravenously for 3-21 days (mean 5.4 days) and 50 patients imipenem/cilastatin 500 mg/500 mg t.i.d . intravenously for 3-17 days (mean 5.1 days) . Three serum samples were taken from each patient, the first sample at admission, the second sample between three and seven days after start of antibiotic treatment, and the third sample between 14 and 28 days later . Ninety-eight per cent of the patients in the meropenem group and 95% of the patients in the imipenem/cilastatin group were cured . There was no difference in the clinical outcome between the two treatment groups . Escherichia coli, Bacteroides fragilis group, anaerobic cocci, Staphylococcus epidermidis, and Klebsiella spp . predominated among the isolated microorganisms . Thirty-nine patients in the meropenem group had significant immune responses against one or more of the isolated microorganisms while 31 patients in the imipenem/group had significant responses . E . coli and B . fragilis gave rise in antibody titres in most patients indicating that these species are the most important pathogens in intraabdominal infections.

Biochimie, 1994, 76(5), 384 - 8
Chain condensation in protein folding; Chen HM et al.; Three reactions (relaxation times: tau 1 = 140 +/- 8 ms, tau 2 = 840 +/- 30 ms and tau 3 = 30 + 3 s, at pH 7.0 at 25 degrees C) have been resolved by the stopped-flow kinetic method for the folding of the acid denatured staphylococcal nuclease (Chen et al (1991) J Mol Biol 220, 771; Biochemistry (1992) 31, 1483) . Of the three reactions only the tau 2 reaction was dependent on the viscosity of the solution in a manner consistent with the diffusion/collision/coalescence model . Experiments with site-directed mutagenesis suggest that the forming of local structures by the electrostatic interactions between Glu75 and His121 and Lys9 may induce the chain condensation.

Acta Neurobiol Exp (Wars), 1994, 54(3), 219 - 25
Effects of staphylococcal alpha-toxin on the ultrastructure of the rat hypothalamo-neurohypophyseal system; Gajkowska B et al.; The influence of staphylococcal alpha-toxin on the ultrastructure of hypothalamo-neurohypophysical system in the brain (nucleus supraopticus, nucleus paraventricularis, neurohypophysis) was studied in the rat . In neurohypophysis, an area lacking blood-brain barrier, alpha-toxin damaged both neuronal endings and capillary vessels . On the other hand in hypothalamus, where blood-brain barrier is present structural alterations were much less pronounced . Reactive gliosis, accordant with cell damage, was observed in the entire neurosecretory system . Putative mechanisms leading to brain damage after systemic administration of alpha-toxin, including direct disruption of cell membrane and induction of nitric oxide synthesis, are discussed.

Vox Sang, 1994, 67(2), 154 - 9
In vitro platelet function during storage in three different additive solutions; Koerner K et al.; Three different synthetic media without glucose were studied for platelet storage . The first medium contained acetate and gluconate . The second contained acetate, gluconate and citrate . Finally the third contained phosphate and mannitol . The purpose of the study was to investigate whether there were differences among the various media in terms of preservation of platelet quality . Pools of platelet concentrates were prepared from buffy coats . In vitro function and metabolic parameters were measured during 5 days of storage in these additive solutions as well as in plasma . Platelet aggregation, hypotonic shock response and release of beta-thromboglobulin, platelet factor 4 and lactate dehydrogenase of the cytosol were equivalent in the media containing acetate compared to plasma storage . In vitro platelet functions and pH in these two media were better preserved compared to the medium with phosphate and mannitol . In addition bacteriological studies using platelets suspended in additive solutions or in plasma were carried out . Carryover of 20% of plasma to the synthetic media necessary for successful platelet storage in these additive solutions allows bacteriological growth . As shown, inoculation of 1 colony/ml Staphylococcus epidermidis leads to 10(6)-10(7) organisms/ml after 5 days of storage.

Probl Tuberk, 1994, (6), 19 - 21
{Initial and minor symptoms of tuberculosis in children}; Priimak AA et al.; The authors studied the diagnosis of initial and minor tuberculous manifestations in risk-group children using conventional and compementary methods . The latter comprised aspirin and blood chemiluminescence (CL) tests . The aspirin test rejected the infection as a cause of fever in 11.2% of the examinees . The addition to leukocytes of M . tuberculosis (BCG and staphylococcus strains) induced an intensive CL response to BCG mycobacteria observed in minor tuberculosis, whereas infected subjects with associated diseases displayed enhanced CL in response to staphylococcus.

Rev Chir Orthop Reparatrice Appar Mot, 1994, 80(7), 642 - 50
{Surgical treatment of chronic hematogenous osteomyelitis . A series of 42 cases}; Martini M et al.; INTRODUCTION: Chronic hematogenous osteomyelitis (C.H.O.) is still a scourge of the non-industrialized countries . The authors operated on 420 cases of C.H.O . in Algeria between 1968 and 1987 . A computerized analysis of the results of the surgical treatment of these 420 cases was made in Brussels, Belgium, by two of the authors . The results of this computerized study are exposed . MATERIAL AND METHODS: 67.1 per cent of the patients were male and 37.9 female . 68 per cent were operated before 16 y . of age . 381 lesions involved tubular bones: femur, tibia and humerus were the most frequent locations . Only 4 per cent of the cases had never presented a suppuration . Cultures of Staphylococcus were positive in 82 per cent of the cases . Surgical procedure was classical--bone window opening, sequestrectomy and saucerisation--in 359 cases . Operation was limited to soft tissues in 22 cases and bone resection was performed in 39 cases . Post-operative antibiotherapy was administered for a period of 10 to 60 days according to the patients . RESULTS: After the first operation with the classical procedure, results were satisfactory in 72 per cent of the cases but "healing" was achieved in 95 per cent of the cases after 2, 3, 4 and up to 6 operations . After bone resection, the rate of permanent healing was of 100 per cent . Follow-up was of more of 1 year (up to 22 y.) in 80 per cent of the cases . DISCUSSION: As far as classical procedure is concerned, a computerized analysis made according to 34 variables, led to the conclusions that the following variables could have a positive influence upon the prognosis: surgical team's experience, young age of the patient at the time of operation, subacute onset of the disease, location on the humerus, diaphysis of long bones, membranous and short bones, small number of sinuses, sclero-geodic radiologic appearance of the lesions, thin perifocal radiologic condensation, periosteal reaction, post-operative administration of two antibiotics . Excellent results of bone resection are pointed out but attention is drawn on the dangers of extending the indications for resection to the tubular bones . CONCLUSION: The authors conclude that improvement in the results of the surgical treatment of C.H.O . may only take place after improvement of the quality and duration of chemotherapy: that is confirmed by the results of a clinical trial they organized on the role of post-operative administration of Amoxicilline + Clavulanic Acid for a period of 60 days after surgery: 44 patients, 2 lost to follow-up, 4 failures and 38 "healings" (90.5 per cent) at 2 years and more.

Int Rev Immunol, 1994, 11(4), 321 - 42
Apoptosis defects analyzed in TcR transgenic and fas transgenic lpr mice; Mountz JD et al.; Although autoreactive T cells are thought to play a prominent role in autoimmune disease in MRL-lpr/lpr mice, it has been difficult to directly determine if autoreactive T cells escape from the thymus and react with self-antigens in the periphery . Defective expression of the Fas apoptosis antigen in MRL-lpr/lpr mice results from the insertion of the ETn retrotransposon . The fas defect can be partially corrected in CD2-fas transgenic mice in which the expression of fas is corrected in T cells . To identify a possible defect in clonal deletion or clonal anergy induction of auto-specific T cells, we have studied C57BL/6-lpr/lpr transgenic mice that express TcR genes that recognize a known self-antigen, the male H-Y antigen . In addition, we have analyzed clonal deletion and tolerance induction after neonatal tolerance induction and superantigen-induced arthritis with the class II MHC reactive superantigen staphylococcal enterotoxin B (SEB) in V beta 8 TcR transgenic and non-transgenic MRL-lpr/lpr mice . Neonatal tolerance induction to SEB was normal in lpr/lpr mice . However, over time a loss of tolerance (thymic or peripheral) was observed in lpr/lpr mice but not in +/+ TcR transgenic mice . This defect in lpr/lpr mice was thymic-dependent and was due to increased CD28/CTLA4 signaling . These results suggest that an apoptosis defect involving both thymocytes and peripheral lymphoid cells leads to autoimmune disease in lpr/lpr mice . The challenge in the future will be to determine the role of defective apoptosis in other autoimmune diseases.

Dermatology, 1994, 189 Suppl 1, 14 - 7
Clinical and immunological analysis of annular erythema associated with Sjögren syndrome; Katayama I et al.; Clinical and immunopathological analysis was performed on 24 cases of Sjogren syndrome with annular erythema (AESjS) . AESjS predominantly appears on the cheek of the face where skin temperature is relatively low in comparison with other sites . VCAM-1 and ICAM-1 were strongly expressed on endothelial cells of AESjS, while epidermal expression of ICAM-1 was focal and weak . VCAM-1 mRNA expression was also much more intense compared to systemic lupus erythematosus . The lymphocyte response to staphylococcal enterotoxin B was higher in AESjS than that of controls, and cells positive for T cell receptor V beta 6,9,12 were expanded after the culture . Superantigen-driven endothelial-cell-dependent T cell infiltration to the skin plays a crucial role in AESjS.

Eur J Immunol, 1994 Jan, 24(1), 265 - 72
T cell receptor stimulation, but not CD28 costimulation, is dependent on LFA-1-mediated events; Green JM et al.; Accessory molecules play a crucial role in the development of the T cell response to antigenic challenge . In this manuscript we specifically examine the role of two accessory molecules, CD28 and LFA-1, in modulating the T cell proliferative response to a variety of stimuli . We demonstrate that the proliferation induced by staphylococcal enterotoxins A and B in combination with CD28 costimulation is dependent on LFA-1-mediated events . This requirement for LFA-1 is independent of T cell-accessory cell adhesion . Similarly, an allogeneic mixed lymphocyte reaction, which has previously been shown to be a CD28-dependent response, can be inhibited by blockade of LFA-1 . This suggests LFA-1 plays an essential role in these responses, either by enhancing intercellular adhesion or by an independent signal transduction event . In contrast, when the primary activating stimulus is delivered by immobilized anti-CD3 antibody or by PMA, and the secondary stimulus by either alpha-CD28 or cell-bound CD28 ligand B7, there is no requirement for LFA-1 . In addition, we demonstrate that cross-linking of LFA-1 with immobilized monoclonal antibody, or engagement of LFA-1 with ICAM-1 expressed on the surface of a CHO cell, provide an insufficient costimulus for T cell proliferation initiated by enterotoxin, immobilized alpha-CD3 or phorbol ester . Our data suggests that LFA-1, in contrast to CD28, functions not as a costimulatory molecule, but serves primarily to modulate the signal delivered through the T cell receptor.

J Immunol, 1993 Dec 15, 151(12), 6777 - 82
Bacterial superantigens induce rapid and T cell receptor V beta-selective down-regulation of L-selectin (gp90Mel-14) in vivo; Miethke T et al.; Upon challenge of mice with bacterial superantigens such as staphylococcal enterotoxin B, several facets of TCR V beta-selective acute T-cell alterations can be observed, which include acute T cell priming, and systemic lymphokine release followed by ligand-specific unresponsiveness . Prompted by experiments showing that stimulation of T cells by phorbol esters in vitro results in rapid shedding of the L-selectin homing receptor, we investigated the expression of adhesion molecules on superantigen-responsive T cells in vivo . Here we show that bacterial superantigens cause TCR V beta-specific loss of L-selectin . Down-regulation of L-selectin was selective, since the expression of other lymphocyte surface receptors was not changed . L-Selectin down-regulation represents a superantigen-induced immediate cell surface alteration and was not observed on T cells stimulated by TCR-specific antibodies . Loss of expression was almost complete within 30 min, and recovered 50 h after challenge . The results suggest that acute loss of L-selectin is a hallmark of T cell activation by bacterial superantigens that may result in profound changes of T lymphocyte recirculation pathways.

Biochim Biophys Acta, 1993 Dec 8, 1203(2), 243 - 50
Estimation of stabilities of staphylococcal nuclease mutants (Met32-->Ala and Met32-->Leu) using molecular dynamics/free energy perturbation; Yamaotsu N et al.; We performed molecular dynamics (MD)/free energy perturbation (FEP) calculations to reproduce the experimental free energy difference of denaturation for staphylococcal nuclease mutant Met32-->Ala (M32A) and to predict the stability of the mutant Met32-->Leu (M32L) . The calculated free energy difference of denaturation for the M32A of -1.9 kcal/mol was in good agreement with the experimental value . In the M32A, a small hydrophobic core formed by three aromatic rings (Tyr-27, Phe-34, Phe-76) in a wild-type crumbled as a result of exposure to water . The van der Waals interactions in the native state of the M32A were weaker than those of the wild-type, which strongly suggests that the Met-32 is important for the stability of the enzyme . The M32L has not been available yet, but is expected to retain the small hydrophobic core . The free energy difference of denaturation for the M32L was calculated to be 1.6 kcal/mol . The MD/FEP simulation showed that the native state structure of the M32L was only slightly changed when compared with that of the wild-type . It was suggested that the M32L is more stable than the wild-type because the electrostatic interactions in the denatured state are more disadvantageous than those in the native state.

J Biol Chem, 1993 Dec 5, 268(34), 25722 - 7
Binding affinity and inhibitory properties of a single-chain anti-T cell receptor antibody; Schodin BA et al.; The antigen-specific function of T cells is mediated through a surface receptor (alpha beta) . Antibodies to the receptor can either inhibit or activate the T cell depending on the multimeric form of the antibody and the isotype of the antibody constant regions . To further examine and eventually control these antagonistic properties, an anti-receptor antibody (1B2) was engineered by linking the variable region genes of the heavy and light chains to form a single-chain binding domain (scFv) . The native 1B2 antibody recognizes determinants on the variable regions of both the alpha and beta subunits of the T cell receptor . The scFv gene was expressed in Escherichia coli, and after folding by dilution of solubilized inclusion bodies, scFv protein was purified as both a 29,000-Da monomer and a noncovalently associated 54,000-Da dimer . The binding affinity of the monomer (KD = 17 nM) was 20-fold lower than that of 1B2 Fab fragments (KD = 0.9 nM) . In contrast, the binding affinity of the dimer (KD = 1.6 nM) was approximately 2-fold lower than that of 1B2 Fab fragments . Both forms were able to inhibit recognition by the T cell, but the dimer was significantly more effective than the monomer . Inhibition was observed for T cell recognition of either the conventional ligand (a peptide bound to a class I product of the major histocompatibility complex) or the "superantigen" ligand (staphylococcal enterotoxin B bound to a class II product of the major histocompatibility complex) . The results suggest that scFv dimers are the most active form of at least some scFv preparations and that the dimers may have the most potential for inhibiting detrimental in vivo T cell activity.

Biophys Chem, 1993 Dec, 48(2), 123 - 33
Compact thermally-denatured state of a staphylococcal nuclease mutant from resonance energy transfer measurements; Wu PG et al.; Thermal denaturation of a staphylococcal nuclease mutant K78C, where lysine 78 is replaced by cysteine, was studied by circular dichroism (CD) and resonance energy transfer . CD spectra suggest that residual structures remain in the denatured state . Steady-state energy transfer from intrinsic tyrosines to a single and intrinsic tryptophan was measured at different temperatures . In the thermally-denatured state of K78C, there is still a substantial degree of energy transfer from tyrosine(s) to tryptophan, indicating residual structures in the denatured state . The cysteine residue in mutant K78C was labeled with a cysteine specific probe IAEDANS . Fluorescence decays of the tryptophan were measured to estimate distance distributions between Trp 140 and IAEDANS at position 78 . Measurements were done as a function of temperature from 4 degrees C (native) to 65 degrees C (denatured) both with and without Ca2+ and inhibitor pdTp . Below 30 degrees C, the apparent distance distribution of both the ligand-free nuclease and the enzyme with bound pdTp can be adequately described by a Gaussian model . Above 40 degrees C, where the ligand-free nuclease but not the ternary complex begins to denature, two different populations are required to fit the data both with and without pdTp . One population has a compact structure and the other has an expanded structure . As temperature rises, the population of the expanded structure increases . At the highest temperature, the non-native compact structure is still the major form (60 to 70%) . The overall thermally-denatured states of staphylococcal nuclease mutant K78C in the absence and presence of ligands are thus compact and heterogeneous.

Am J Physiol, 1993 Dec, 265(6 Pt 1), C1630 - 6
Intracellular mechanism of Pb(2+)-induced norepinephrine release from bovine chromaffin cells; Tomsig JL et al.; The intracellular mechanism of Pb(2+)-induced release of norepinephrine (NE) was investigated in comparison with Ca2+ in bovine chromaffin cells permeabilized with staphylococcal alpha-toxin . Pb2+ activated NE release at considerably lower concentrations {concentration of free metal giving half maximal metal-dependent release (K0.5) 4.6 nM} than Ca2+ (K0.5 2.4 microM) . The release of NE was associated with the release of dopamine-beta-hydroxylase but not lactate dehydrogenase . The maximal secretory responses produced by Pb2+ and Ca2+ were similar and nonadditive . Pb(2+)- and Ca(2+)-dependent releases showed a similar requirement for MgATP and were equally enhanced by protein kinase C activator 12-O-tetradecanoylphorbol 13-acetate (TPA) but not by kinase A activator 8-bromoadenosine 3',5'-cyclic monophosphate free base . The protein kinase C inhibitor staurosporine blocked the TPA-stimulated component of secretion but had no effect on the NE release in the absence of TPA . Calmidazolium, an inhibitor of calmodulin, inhibited the secretion evoked by both metals to similar extent . Agents interacting with microtubules (colchicine and vinblastine) or microfilaments (cytochalasin B and phalloidin) had no effect on secretion induced by either metal cation . These observations indicate that both Pb2+ and Ca2+ act at a common site and activate the exocytotic release of NE by an analogous mechanism.

Eur J Immunol, 1993 Dec, 23(12), 3194 - 202
HLA class II molecule-mediated signal transduction mechanism responsible for the expression of interleukin-1 beta and tumor necrosis factor-alpha genes induced by a staphylococcal superantigen; Matsuyama S et al.; Superantigens including staphylococcal enterotoxins (SE) bind to major histocompatibility complex class II molecules and interact with T cells bearing particular V beta chains . SEB was shown to induce the expression of interleukin (IL)-1 beta and tumor necrosis factor (TNF)-alpha genes in human peripheral blood monocytes bearing HLA class II molecules . Monoclonal antibodies directed against HLA-DR and -DQ abolished the SEB-induced expression of both the IL-1 beta and TNF-alpha genes, suggesting that the HLA class II molecules mediated the gene expression . Therefore, we investigated the signal transduction mechanism responsible for the expression of IL-1 beta and TNF-alpha genes induced by binding of SEB to the HLA class II molecules . Three protein tyrosine kinase (PTK) inhibitors, genistein, herbimycin A, and tyrphostin, each of which has a different mechanism of action, strongly inhibited the expression of the monokine mRNA induced by SEB . Analyses of PTK activity revealed that SEB induced a rapid increase of membrane-associated PTK activity and this was blocked by tyrphostin . Furthermore, H-7 inhibited the expression of the monokine mRNA induced by SEB, suggesting the involvement of protein kinase C (PKC) in the signaling pathway . The involvement of PKC was confirmed by the observations that phorbol 12-myristate 13-acetate (PMA), a direct activator of PKC, induced the expression of the monokine mRNA and that SEB evoked the activation of membrane-associated PKC . Both activation of PKC and expression of the monokine mRNA induced by SEB appeared to be inhibited by tyrphostin, but those induced by PMA were not . Taken together, these findings indicate that both PTK and PKC play essential roles in HLA class II molecule-mediated signal transduction elicited by SEB and that PTK activation may precede PKC activation in the signaling pathway.

J Surg Res, 1993 Dec, 55(6), 640 - 6
Prevention of catheter-related infections by antiseptic bonding; Bach A et al.; A novel catheter pretreated with the antiseptics chlorhexidine and silver-sulfadiazine, designed to reduce catheter-related colonization and infection, was tested in both in vitro and in vivo studies . In vitro experiments demonstrated the long-lasting antibacterial properties of this catheter . For the in vivo study a total of 40 rats divided into different experimental groups were used . Colonization rates of both antiseptic bonded (AS) and control (C) catheters were assessed either three (-3) or seven (-7) days after implantation and local challenge using live Staphylococcus epidermidis ATCC 35984 with 10(7) colony-forming units (cfu) per inoculum . At the time of removal, catheters, organ specimens, and blood samples were taken for cultivation . Significant reductions in the magnitude of colonization of the antiseptic catheters by the test organism were observed in all groups . The average number of cfu colonizing control segments exceeded those found on the treated catheter segments by log 3 (C3/AS3) and log 5 (C7/AS7), respectively (C3: 1.2 x 10(6) +/- 4.1 x 10(5) cfu/segment and AS3: 1.8 x 10(3) +/- 6.6 x 10(2); C7: 2.7 x 10(5) +/- 8.6 x 10(4) and AS7: 1.1 +/- 0.7; mean +/- standard error of the mean, all differences between matching groups statistically significant, Wilcoxon rank sum test, P < 0.0001) . These data suggest that antiseptic catheters may substantially decrease the magnitude of catheter-related microbial colonization and subsequent catheter-related infections and may offer a more effective alternative to current methods.

Exp Hematol, 1993 Dec, 21(13), 1680 - 5
Invalidity from nonparallelism in a radioimmunoassay for erythropoietin accounted for by human serum antibodies to rabbit IgG; Deacon R et al.; An immunologic crossreactant of erythropoietin seemed to develop and persist in serum samples from a patient during treatment and remission of idiopathic aplastic anemia . It had a steeper slope to radioimmunoassay log-dose response lines and a larger molecular size than erythropoietin . On fractionation of serum, the apparent crossreactant was bound by staphylococcal Protein A at pH 7.5 and recovered by elution from it at pH 3.0 . Adsorption of serum from the patient, and from one of two similarly affected children, with rabbit IgG linked to agarose appeared to remove completely the apparent crossreactant . These treated sera gave radioimmunoassay log-dose response lines essentially parallel to that given by the International Reference Preparation (IRP) for erythropoietin and estimates of immunoreactive erythropoietin appropriate to the normal hemoglobin concentrations . The apparent crossreactant of erythropoietin is thus accounted for by heterophilic antibodies to rabbit IgG . These developed in the patient following treatment with rabbit antilymphocyte globulin but seem to have arisen spontaneously in the children . Thus iatrogenic and idiopathic antibodies to rabbit IgG interfered in a radioimmunoassay for erythropoietin in serum through their ability to react with the radioimmunoassay anti-erythropoietin antiserum raised in rabbits.

J Oral Maxillofac Surg, 1993 Dec, 51(12), 1294 - 301
Osteomyelitis of the jaws: a 50-year perspective; Hudson JW; The incidence of osteomyelitis of the jaws has decreased dramatically, except for a few subsets of individuals . This has been due, in no small part, to the availability of bacteriocidal antimicrobial therapy . The pathogenesis of osteomyelitis of the jaws is predominately due to odontogenic microorganisms rather than the classic skin contaminant, Staphylococcus . This causative relationship relegates the classification of osteomyelitis of the bimaxillary skeleton to predominately that of contiguous foci . These may be regionally progressive, secondary to microvascular compromise brought about by inherent flaws in regional anatomic calcified tissue vascular perfusion as well as by inflammatory metaplastic processes . Diagnosis is based on the presence of painful sequestra and suppurative areas of tooth-bearing jaw bone unresponsive to debridement and conservative therapy . This is usually accompanied by regional or systemic compromise of the immune response, microvascular decompensation, or both . Treatment of both acute and chronic forms of the disease, as outlined in Table 5, is successful if surgically supported . Sustained bacteriocidal antibiotic therapy is pertinent, especially in the face of potentially refractory virulent microorganisms and compromised regional vascular penetrance . The use of adjunctive hyperbaric oxygen therapy also may be included in the more refractory forms of osteomyelitis of the jaws to enhance the local and regional immune response of the jaws as well as to produce microvascular neoangiogenesis for reperfusion support . With resolution of infection, hard and soft tissue reconstruction may be necessary to augment the reparative process.

Infect Immun, 1993 Dec, 61(12), 5333 - 8
Toxicity of staphylococcal enterotoxins potentiated by lipopolysaccharide: major histocompatibility complex class II molecule dependency and cytokine release; Stiles BG et al.; The biological effects of staphylococcal enterotoxins (SE), potentiated by bacterial lipopolysaccharide (LPS), were studied with mice . Control animals survived the maximum dose of either SE or LPS, while mice receiving both agents died . SEA was 43-fold more potent than SEB and 20-fold more potent than SEC1 . The mechanism of toxicity was further examined with transgenic mice deficient in major histocompatibility complex class I or II expression . Class II-deficient mice were resistant to SEA or SEB . However, class I-deficient animals were less susceptible to SEA (30% lethality) than wild-type mice (93% lethality) . In vitro stimulation of T cells from the three mouse phenotypes by SEA correlated well with toxicity . T cells from transgenic or wild-type mice were similarly responsive to SEA when presented by irradiated, wild-type mononuclear cells . These data confirmed that the toxicity of SE was mainly exerted through a mechanism dependent on the expression of major histocompatibility complex class II molecules . Toxicity was also linked to stimulated cytokine release . Levels in serum of tumor necrosis factor alpha, interleukin-6, and gamma interferon peaked 2 to 4 h after the potentiating dose of LPS but returned to normal within 10 h . Concentrations of interleukin-1 alpha were also maximal after 2 h but remained above the background for up to 22 h . Relative to the levels in mice given only SEA or LPS, the levels in serum of tumor necrosis factor alpha, interleukin-6, and gamma interferon increased 5-, 10-, and 15-fold, respectively, after injections of SEA plus LPS . There was only an additive effect of SEA and LPS on interleukin-1 alpha concentrations.

EMBO J, 1993 Dec, 12(12), 4803 - 11
Cell wall sorting signals in surface proteins of gram-positive bacteria; Schneewind O et al.; Staphylococcal protein A is anchored to the cell wall, a unique cellular compartment of Gram-positive bacteria . The sorting signal sufficient for cell wall anchoring consists of an LPXTG motif, a C-terminal hydrophobic domain and a charged tail . Homologous sequences are found in many surface proteins of Gram-positive bacteria and we explored the universality of these sequences to serve as cell wall sorting signals . We show that several signals are able to anchor fusion proteins to the staphylococcal cell wall . Some signals do not sort effectively, but acquire sorting activity once the spacing between the LPXTG motif and the charged tail has been increased to span the same length as in protein A . Thus, signals for cell wall anchoring in Gram-positive bacteria are as universal as signal (leader) sequences.

Circ Res, 1993 Dec, 73(6), 1150 - 62
Determinants of loaded shortening velocity in single cardiac myocytes permeabilized with alpha-hemolysin; Sweitzer NK et al.; Force-velocity relations were obtained from single cardiac myocytes isolated by enzymatic digestion of rat myocardium and permeabilized with the pore-forming staphylococcal toxin alpha-hemolysin . Single cardiac myocytes were attached to a force transducer and piezoelectric translator and viewed with an inverted microscope to allow periodic monitoring of sarcomere length during experiments . Permeabilized cells were activated by immersion in a bath of known {Ca2+} . We report that the Ca2+ sensitivity of cells obtained by enzymatic digestion and permeabilized using alpha-hemolysin is similar to that reported previously for mechanically disrupted ventricular myocardium; however, the tension-pCa relation is less steep in the new preparation . During isotonic measurements, force was clamped to various loads using a rapid-response servo system . All recordings of shortening under load were distinctly curvilinear, and analysis of data involved fitting each shortening recording with a single exponential curve and calculating the value of the slope at the initial time of the load clamp . In addition, the presence of significant resting force at initial sarcomere lengths in these cells required that the possibility of alteration of velocity due to the presence of resting force be addressed . The maximum shortening velocity in fully Ca(2+)-activated single ventricular myocytes studied by this method was 2.83 muscle lengths per second on average . The basis for curvilinear shortening is postulated to be multifactorial in cardiac muscle, involving a combination of shortening inactivation and one or more passive elasticities that resist stretch or compression depending on sarcomere length . Shortening velocity shows a dependence on myosin isoform content when cells from a single heart are compared; however, this relation does not hold when cells from different hearts are compared . The behavior of single alpha-hemolysin-permeabilized myocyte shortening under loaded conditions at lower levels of Ca2+ is also described . During submaximal Ca2+ activation, initial shortening velocities are faster than those observed in maximally activated cells . This may be due to contributions of high passive force to increase shortening velocity under conditions of low active force generation, when passive force in the cell is a greater proportion of the total force and there are fewer bound crossbridges.

Arq Bras Cardiol, 1993 Dec, 61(6), 349 - 55
{Neurological events in infective endocarditis}; Lunardi W et al.; PURPOSE--The study of frequency, modalities and course of neurological complications of infective endocarditis (IE), as well as the current indication and value of supplementary examinations . METHODS--Sixty-three patients with IE, 39 with native valve and 24 with valvar prosthesis, were prospectively studied; the mean age was 42 years and 45 (71.4%) were males . Two groups were formed: A) 41 patients without neurological events and B) 22 patients who presented 28 neurological events before or during hospitalization: ischemic cerebrovascular accident 20, hemorrhagic cerebrovascular accident 2, meningeal hemorrhage 2, meningitis 2, brain abscess 1 and seizure 1 . All patients were submitted to neurological clinical examination; 57 computerized tomographies of the cranium, 28 arteriographies and 32 cerebrospinal fluid analysis were performed . RESULTS--The incidence of neurological events corresponded to 34.92% of IE patients, with a clear predominance (85.71%) of vascular as compared to infectious manifestations . Mortality was 2.32 times higher in group B patients (22.73% x 9.76%), albeit p = 0.256, and was not related to staphylococcal etiology . The neurological events were not related to sex, age and presence of valvar prosthesis . The presence of neurological complications was greater (p = 0.047) in patients with simultaneous infections in two valves (mitral and aortic) and also (p = 0.00884) in those with IE in prosthesis implanted for less than three months . All supplementary neurological examinations in group A were normal . CONCLUSION--1) Occurrence of neurological events is a factor which influences the prognosis of IE; 2) supplementary neurological examinations did not reveal subclinical neurological complications; 3) neurological complications were significantly more frequent in patients with simultaneous mitral and aortic valve IE; 4) IE in prosthesis implanted for less than 3 months has a greater probability to develop a neurological picture as compared to IE in prosthesis implanted for more than 3 months.

Int Orthop, 1993 Dec, 17(6), 367 - 74
{Primary arthritis of the hip in adults}; Evrard J et al.; Between 1950 and 1991 the authors have treated 45 adults with primary septic arthritis of the hip, not including tuberculosis . The mortality rate was 13% . There is an accompanying septicaemia, or, more commonly, a bacteraemia, and other general and local factors are often present . The diagnosis may be obvious, but in 50% of cases the presentation may be atypical and the clinical diagnosis uncertain . Confirmation of the diagnosis is by a positive culture from the aspirate, and a Staphylococcus is the usual organism found . The various methods of management used are discussed and the literature analyzed . Wide drainage of the hip is recommended . Arthrodesis is now rarely necessary, and a total replacement arthroplasty may be undertaken when the infection has been controlled . Six out of seven such procedures carried out in their unit in the last 10 years have been successful.

Enferm Infecc Microbiol Clin, 1993 Dec, 11(10), 525 - 30
{Community-acquired pneumonia: prospective study of 101 adult, immunocompetent patients for 1 year}; Antela A et al.; BACKGROUND: A one year prospective study was carried out to assess the etiology of community-acquired pneumonia (CAP), and also to know the incidence, characteristics and evolution of infection by Chlamydia pneumoniae; and the effectiveness of DNA probes in CAP due to Mycoplasma pneumoniae and Legionella . METHODS: One hundred and ten patients with a diagnosis of CAP in the emergency department were studied . Serologic studies were performed, and also tests commonly used for the diagnosis of respiratory tract pathogens in respiratory samples, including serology and culture of Chlamydia pneumoniae and DNA probes for Mycoplasma pneumoniae and Legionella . RESULTS: In 72 cases (71.3%) some pathogen was found and in 5 cases more than one microorganism was involved . The etiology was bacterial in 31% of the cases, with S . pneumoniae being the most frequent (19 cases) . Forty percent of the cases were "atypical" pneumonias with 33 cases of M . pneumoniae and 5 by Chlamydia pneumoniae . Diagnostic data of viral pneumonia were found in 2 cases . DNA probes were not useful for the diagnosis of pneumonia by Legionella pneumophila and had low effectiveness (31.8%) in Mycoplasma pneumoniae CAP . CONCLUSIONS: a) M . pneumoniae was the most frequent pathogen (33%) . b) DNA probes for M . pneumoniae had low sensitivity in sputum (31.8%) and none in pharyngeal exudate . c) Acute infection by C . pneumoniae was diagnosed in 5 cases . Previous data of infection were recorded in 60.4% of the patients . d) Bacterial pneumonia (31%) was underestimated due to a low rate of bacteremic cases (7.9%) and the low number of positive cultures with definitive diagnostic value . e) The evolution was good except in two cases (death due to staphylococcal pneumonia with alcohol withdrawal syndrome and multiorganic failure by disseminated chicken-pox).

J Biochem (Tokyo), 1993 Dec, 114(6), 813 - 9
Improved method for expression of Kunitz-type serine proteinase inhibitor domain of beta-amyloid protein precursor in Escherichia coli and characterization of disulfide bonds of the product; Oyama F et al.; Kunitz-type serine proteinase inhibitor (KPI) domain of Alzheimer's disease-related beta-amyloid protein precursor (APP) was expressed in Escherichia coli as a fusion protein with a truncated form of Staphylococcus protein A . The fusion protein was purified from the cell culture medium using an IgG Sepharose column . The KPI domain was separated from the protein A portion by cleavage with human alpha-thrombin at the engineered recognition sequence, followed by purification on IgG Sepharose and reversed-phase HPLC columns . The recombinant KPI domain strongly inhibited trypsin; the inhibition constant (Ki) for bovine trypsin was 2.5 x 10(-11) M, comparable to those of the secreted forms of APP with the KPI domain . The recombinant protein contained three intramolecular disulfide bonds, which were determined to be located between Cys-6 (C1) and Cys-56 (C6), Cys-15 (C2) and Cys-39 (C4), and Cys-31 (C3) and Cys-52 (C5) of the recombinant KPI domain, respectively . These positions are highly homologous to those of disulfide bonds in bovine pancreatic trypsin inhibitor . The trypsin-inhibitory activity of the recombinant protein was abolished by preincubation with 0.4 mM dithiothreitol under non-denaturing conditions . By this mild reduction, all the disulfide bonds were completely cleaved . These results clearly indicate that the disulfide bonds play an important role in the function of the KPI domain of APP.

J Biochem (Tokyo), 1993 Dec, 114(6), 800 - 7
Purification, some properties, and primary structure of a base non-specific ribonuclease from oyster (Crussdstrea grigus); Watanabe H et al.; A ribonuclease (RNase Oy) was purified to homogeneity on SDS-PAGE from the homogenate of oyster (Crussdstrea grigus) . The apparent molecular weight estimated from SDS-PAGE was ca . 28 kDa . The pH optimum of the RNase was 5.0 . The RNase released mononucleotides from RNA in the order of 3'-GMP, 3'-AMP, and 3'-UMP . The complete amino acid sequence of RNase Oy was determined, mostly by analyzing the peptides generated by BrCN cleavage or digestion by lysylendopeptidase, staphylococcal V8 protease, and alpha-chymotrypsin . The molecular weight of the protein moiety of RNase Oy deduced from the sequence was 24,359 . The sequence of RNase Oy contained two typical histidine residues in segments common to the active site of RNase T2 family enzymes . The locations of six half cystine residues among eight were almost superimposable on those of four known plant RNases of RNase T2 family . The sequence homology between RNase Oy and five fungal and four plant RNases amount, to 43-56 amino acid residues . The amino acid sequence of the N-terminal part of RNase Oy is more similar to those of plant RNases than to those of fungal RNases . This RNase is the first RNase T2 family RNase from mollusc whose primary structure has been elucidated.

J Gen Microbiol, 1993 Dec, 139 ( Pt 12), 2939 - 44
Molecular characterization of the coagulase-negative staphylococcal surface flora of premature neonates; Bialkowska-Hobrzanska H et al.; A single point study was conducted to determine which surface sites best represent the density and composition of the coagulase-negative staphylococcal (CNS) colonizing flora in premature neonates . Five different surface sites of six randomly selected neonates hospitalized in a neonatal intensive care unit (NICU) for a month were examined . The individual strains and their clonal organization within CNS species were identified using restriction endonuclease fingerprinting of whole chromosomal DNA and ribosomal RNA genes . Cultures of the scalp, umbilicus, foot, nose and rectum were collected and quantitatively processed . Ten colonies were typed per surface culture . The most dense CNS colonization was noted on the umbilicus (mean 1.2 x 10(4) c.f.u . cm-2), foot (mean 1.6 x 10(3) c.f.u . cm-2) and nose (mean 1.7 x 10(3) c.f.u . cm-2) of NICU neonates . Scalp and rectum were scarcely colonized . Of all the CNS surface isolates, S . epidermidis accounted for 77.7% (219/282) and S . haemolyticus, S . warneri and S . capitis accounted for 20.6% (58/282), 1.4% (4/282) and 0.4% (1/282), respectively . Colonization of each surface site comprised a maximum of five different strains representing four CNS species . Overall, five clones of S . epidermidis, two of S . haemolyticus, one of S . warneri and one of S . capitis were noted among the 282 isolates . The most predominant were two clones of S . epidermidis and one of S . haemolyticus; they accounted for 94% (265/282) . Cultures from the foot and scalp represented the most heterogeneous CNS colonization of the five sites examined.(ABSTRACT TRUNCATED AT 250 WORDS)

J Muscle Res Cell Motil, 1993 Dec, 14(6), 666 - 77
Flash photolysis studies of relaxation and cross-bridge detachment: higher sensitivity of tonic than phasic smooth muscle to MgADP; Fuglsang A et al.; The effects of MgADP and inorganic phosphate (Pi) on cross-bridge detachment were determined in tonic (rabbit femoral artery) and phasic (rabbit bladder and guinea pig portal vein) smooth muscles permeabilized with staphylococcal alpha-toxin . Relaxation from rigor was induced by photolysis of ATP (1.2-1.5 mM) from caged ATP . The initial one second of relaxation from rigor was resolved into two exponential components: a rapid component with normalized amplitudes, Af, of 8, 15 and 26% and rate constants, kf (in s-1) of 26, 36 and 30 in rabbit femoral artery, guinea pig portal vein, and rabbit bladder; the respective rate constants of the second, slower component, ks, were 0.07, 0.2 and 0.1 . Removal of residual endogenous ADP with apyrase treatment increased the amplitude Af and accelerated ks; addition of MgADP reduced Af . The combination of these effects (increases in Af and ks) decreased the t1/2 of relaxation from control values by factors of 2.6 (femoral artery), 6.7 (portal vein) and 10 (bladder) . Pi (30 mM) further increased the amplitudes Af . The affinity of MgADP for myosin cross-bridges, estimated as the reduction of the relative amplitude of the rapid component, Af, was significantly higher in tonic than in phasic smooth muscle: the KD of MgADP was 1.1 +/- 0.3 microM in rabbit femoral artery and 4.9 +/- 1.0 microM in rabbit bladder . The higher affinity of tonic smooth muscle myosin for MgADP correlated with its relatively high LC17b isoform content (58 +/- 4.2%) in contrast to the lower affinity of the phasic, bladder detrusor smooth muscle that contained only the LC17a isoform.(ABSTRACT TRUNCATED AT 250 WORDS)

Monatsschr Kinderheilkd, 1993 Dec, 141(12), 932 - 5
{Pericardial tamponade caused by catheter infection in an extremely small premature infant}; Lawrenz-Wolf B et al.; A 610 g infant born after 27 weeks of gestation required central venous infusion therapy by a 23 gauge silastic catheter with its tip located in the superior vena cava . During adequate antibiotic therapy for sepsis the infant developed cardiac tamponade with circulatory failure . Therapeutic pericardiocentesis revealed pericarditis and not hydropericardium . Central venous infusion could be continued relapse-free without a change in catheter position . After bacteriologic identification of Staphylococcus epidermidis in blood culture and pericardial aspirate, the central venous line was removed and identified as the source of infection by identical bacterial growth from the catheter tip . While cardiac perforation has been recognized as a rare complication of central venous infusion even by very soft and thin silastic catheters, this is to our knowledge the first report on cardiac tamponade from bacterial pericarditis following catheter sepsis in a neonate.

Gynecol Oncol, 1993 Dec, 51(3), 372 - 6
Externalized Groshong catheters and Hickman ports for central venous access in gynecologic oncology patients; Gleeson NC et al.; There is a demand on gynecologic oncology services for semipermanent cannulization of central veins to improve the quality of life in cancer patients by circumventing the need for frequent peripheral venous punctures . Central venous thrombosis and sepsis are the major complications with these lines . We reviewed our experience with the externalized Groshong catheters and subcutaneously implanted Hickman ports in 104 gynecologic oncology patients requiring either chemotherapy (56), hyperalimentation (5), or supportive care (43) . All devices were inserted under the supervision of one primary gynecologic oncologist . Groshong catheters and Hickman ports remained in place for a median of 68.5 and 210 days, respectively (P < 0.001) . Thrombosis occurred in association with 4.8% of catheters and was exclusive to the Groshong catheters . Line sepsis occurred in 32% of Groshong catheters and 16.2% of Hickman ports (P = 0.04) . Infection rates were not higher in dual-lumen compared to single-lumen Groshong catheters . Staphylococcus epidermidis was the comments isolate in line infections . The majority of lines were salvaged despite infectious complications . Malfunction of the catheter was equally common in both groups (10.5-13.5%), but was complete, necessitating replacement of only 2.9% of lines . The Groshong catheters took less time to insert (P < 0.003) . The externalized Groshong catheter remains a useful alternative to the subcutaneously implanted ports, especially when relatively short-term use is anticipated, but gynecologic oncologists should be aware that there is an increased frequency of complications with the externalized catheter.

Arch Mal Coeur Vaiss, 1993 Dec, 86(12 Suppl), 1883 - 8
{Risk of bacterial endocarditis after cardiac surgery}; de Gevigney G et al.; The risk of infective endocarditis (IE) after intracardiac surgery is dominated by the risk of IE on valvular prostheses . The reported prevalence of IE on prosthetic valves varies according to the chosen diagnostic criteria of IE and its timing . The risk of early IE is 0.4 to 1.3% and the linearized annual risk of late IE is about 0.5% . These values appear to be identical irrespective of the type and site of the prosthesis: the risk is higher in multiple valve replacement . In early IE, the commonest infecting organism is the staphylococcus: the bacteriological spectrum of late IE is the same as that of IE on native valves . The portal of entry is often detected in early IE but more rarely (50%) in late IE . The risk of IE in operated congenital heart disease is very low after surgery of left-to-right shunts or valvular stenosis; it is higher for patients with Tetralogy of Fallot and those with complex cyanotic disease, especially in cases with residual ventricular septal defects and with palliative surgery such as systemico-pulmonary anastomosis . The risk of IE on endocavitary catheters (pace-maker, defibrillator) after interventional cardiac procedures and after cardiac transplantation, seems to be very low . These results show that preventive measures against IE are only routinely required in prosthetic valve patients and after surgery of Tetralogy of Fallot and complex cyanotic cardiac disease.

J Hosp Infect, 1993 Dec, 25(4), 251 - 64
Enhanced ability to colonize the skin: a possible explanation for the epidemic spread of certain strains of Staphylococcus epidermidis; Hedin G et al.; Experimental skin colonization was attempted on healthy volunteers using one epidemic and two non-epidemic strains of Staphylococcus epidermidis isolated from a bone marrow transplant unit . Although the three strains had similar biochemical reactions, they had different antibiograms and plasmid patterns, and the epidemic strain grew rather more slowly when in a mixture in broth . Two experiments involving sets of 5 volunteers were performed . The epidemic strain was mixed with one non-epidemic strain for experiment 1, and with the other for experiment 2 . Each volunteer had an inoculum of a mixture of 10(7) cfu of each strain inoculated onto the antecubital fossae of both arms; one of the arms had had a prior treatment with chlorhexidine to see if this would prevent colonization . Quantitative skin cultures were continued until the test strains could no longer be isolated . Colonization occurred in all but one volunteer, and lasted from a few weeks to 17 months . Maximal counts of the epidemic strain were significantly higher than the maximal counts of the non-epidemic strains . Chlorhexidine had no effect in experiment 1, and caused a reduction in intensity and duration of colonization in experiment 2, although this did not achieve statistical significance . Plasmid patterns were unchanged throughout, but in two instances a variant of the epidemic strain that had lost resistance to methicillin and tobramycin was isolated together with the parent strain . The enhanced ability of the epidemic strain to colonize skin may be an important factor in allowing cross-infection.

Cell Immunol, 1993 Dec, 152(2), 594 - 604
The role of class II molecules in Mls 1a recognition by CD4+ T cells is independent of the CD4 molecule; Borrero H et al.; The interpretation of previous antibody inhibition and cell depletion experiments was that major histocompatibility complex (MHC) class II molecules are involved in presentation of Mls molecules to T cell receptors . However, a possible conclusion of several subsequent studies was that T cell receptors may in fact recognize Mls molecules in a class II-unassociated manner . We considered that if this interpretation of the relevant data was correct, the earlier demonstrated role of MHC class II molecules on Mls 1a antigen presenting cells in the response of CD4+ T cells might be only to serve as a ligand for the CD4 molecule on the responder cells . To test the possibility that the inhibition of the anti-Mls 1a response by anti-class II antibodies solely reflected such a CD4:class II molecular interaction, we derived CD4- variants of two independent T cell receptor V beta 6-expressing, Mls 1a-responsive T hybrid clones . Since preliminary experiments to screen for responsiveness revealed that the CD4- variants of both T hybrid clones retained responsiveness to Mls 1a and the variants of one that was also responsive to staphylococcal enterotoxin B retained that responsiveness, we concluded that there is no qualitative dependency of the responses of V beta 6 T cells to these two superantigens on a CD4-mediated activity . More importantly, the responses of the CD4- variants of the two T hybrid clones to Mls 1a retain the same susceptibility to inhibition by antibodies to MHC class II molecules exhibited by the parental T hybrids . These results indicate that the blocking of responses of CD4+ T cells to Mls 1a by both anti-H-2A and anti-H-2E antibodies is not due only to disruption of interactions between CD4 and H-2A or H-2E molecules . The data are thus consistent with the class II molecule-dependent models of Mls 1a presentation to the T cell receptor which are discussed in the light of recent findings on the biochemical nature of the Mls 1a molecule.

J Med Microbiol, 1993 Dec, 39(6), 429 - 33
Characterisation of Staphylococcus intermedius isolates from canine pyoderma and from healthy carriers by SDS-PAGE of exoproteins, immunoblotting and restriction endonuclease digest analysis; Allaker RP et al.; Ten Staphylococcus intermedius isolates from cases of canine pyoderma and 10 from healthy carriers were examined by SDS-PAGE of exoproteins, immunoblotting and restriction endonuclease digest analysis . Similarities between banding patterns of the isolates were calculated as Dice coefficients for all three methods . For SDS-PAGE and immunoblotting, no significant differentiation was found between the pyoderma and "healthy" groups . Analysis of DNA digested with BglII indicated that S . intermedius is genetically heterogeneous; Dice coefficients for the pyoderma group were distinct from those for the healthy group (p < 0.001), and cluster analysis confirmed that the pyoderma isolates (9) formed a group separate from the majority (6 of 9) of the normal isolates.

Blood, 1993 Dec 1, 82(11), 3392 - 400
Accelerated apoptosis in peripheral blood mononuclear cells (PBMCs) from human immunodeficiency virus type-1 infected patients and in CD4 cross-linked PBMCs from normal individuals; Oyaizu N et al.; This study investigates apoptosis as a mechanism for CD4+ T-cell depletion in human immunodeficiency virus type-1 (HIV-1) infection . Although several recent studies have shown that T cells of HIV-infected individuals show enhanced susceptibility to cell death by apoptosis, the mechanisms responsible for apoptosis are largely unknown . By using a flow cytometric technique and by morphology, we have quantitated the percentage of cells undergoing apoptosis in peripheral blood mononuclear cells (PBMCs) from HIV-seronegative donors and from HIV-infected asymptomatic patients . The PBMCs were cultured without any stimulus or with staphylococcus enterotoxin B, anti-T-cell receptor (TCR) alpha beta monoclonal antibody WT-31, or phytohemagglutinin for periods up to 6 days . In addition, we sought to determine whether cross-linking of CD4 followed by various modes of TCR stimulation in vitro could induce apoptosis in normal PBMCs . Here we show that (1) patient PMBCs undergo marked spontaneous apoptosis; (2) stimulation of T cells of patients as well as normal donors results in increased apoptosis; and (3) cross-linking of CD4 molecules is sufficient to induce apoptosis in CD4+ T cells if cross-linking is performed in unfractioned PBMCs, but not if CD4 molecules are cross-linked in purified T-cell preparations . These observations strongly suggest that accelerated cell death through apoptosis plays an important role in the pathogenesis of HIV-1 infection . At the same time, our observations implicate cross-linking of CD4 in vivo as a major contributor to this mechanism of accelerated cell death in HIV infection.

Acta Endocrinol (Copenh), 1993 Dec, 129(6), 579 - 84
FK506 inhibits phytohemagglutinin-, but not interferon-gamma-, induced HLA-DR antigen expression and accessory cell function on primary cultured human thyroid cells; Sato M et al.; We investigated the effects of FK506, a novel immunosuppressive agent, on the phytohemagglutinin (PHA) or interferon-gamma (IFN-gamma)-induced expression of HLA-DR antigen, accessory cell function and proliferation of primary cultured human thyroid cells . Primary cultured thyroid cells from patients with Graves' disease were incubated for 3 days with PHA in concentrations in the range 1-50 mg/l or with 200 kU/l of IFN-gamma, in the presence or absence of FK506 . The surface expression of HLA-DR antigen was measured by flow cytometry . Accessory cell function of thyroid cells was assessed by the incorporation of {3H}thymidine to T cells in the presence of 0.1-1.0 micrograms/l staphylococcus enterotoxin B (SEB) . The proliferation of thyroid cells was determined from {3H}thymidine incorporation assays . FK506 inhibited the induction of HLA-DR antigen expression by PHA on thyroid cells in a dose-dependent manner, but did not inhibit that by IFN-gamma . Polyclonal anti-IFN-gamma antibody partly inhibited the PHA-induced HLA-DR antigen expression on thyroid cells . Phytohemagglutinin enhanced the SEB-mediated accessory cell function of thyroid cells . FK506 inhibited the accessory cell function induced by PHA . FK506 alone did not directly affect the thyroid cell proliferation, although it ameliorated the thyroid cell growth suppressed by PHA . Our data suggest that FK506 suppresses the HLA-DR antigen expression induced by PHA and the subsequent accessory cell function on thyroid cells via the inhibition of T lymphocytes present in the primary culture.

J Immunol, 1993 Nov 15, 151(10), 5822 - 39
Molecular selection of human antibodies with an unconventional bacterial B cell antigen; Sasano M et al.; Unconventional Ag for B cells that are comparable to known superantigens for T lymphocytes have not been well characterized . However, the bacterial membrane protein, Staphylococcal protein A (SpA), has sites that interact with the Fab of many IgM, IgA, IgG, and IgE, and in recent reports we have provided evidence of VH restriction in Fab that bind SpA . To investigate the molecular basis for this Fab binding specificity, we have selected monoclonal Fab from a phage-display combinatorial Ig library, based on the ability to bind SpA . By this approach, in an unselected human polyclonal IgG Fab library, about 17% of antibody-expressing clones were found to bind SpA . SpA binding was completely restricted to Fab with VH3 H chains, and about 60% of VH3 Fab in the unselected library had SpA binding capacity . Analysis of 21 VH sequences and 6 VL sequences demonstrated that Fab that bind SpA use diverse VH3 genes, while the L chains derive from a variety of V kappa and V lambda gene families . By creation of antibodies with differential H-L chain pairing, the global capacity to bind SpA was shown to be dictated by VH3 usage, but different L chain usage could result in up to a fourfold change in binding affinity . The apparent KD of the SpA binding by different Fab ranged from 2.5 x 10(-7) to > 10(-5) M . Furthermore, repeated rounds of in vitro panning selected for antibodies based on higher binding affinity . These data indicate that the pattern of VH family restriction of Ig reactive with SpA is comparable to known superantigens, and there is a hierarchy within the binding affinities of VH3 Fab based on V gene usage.

J Immunol, 1993 Nov 15, 151(10), 5115 - 22
Cross-linking of HLA class II antigens modulates the release of tumor necrosis factor-alpha by the EBV-B lymphoblastoid cell line JY; Altomonte M et al.; In addition to their functional role as peptide-binding proteins HLA class II Ag can also act as signal-transducing molecules . The present study showed that cross-linking of HLA class II Ag by the anti-HLA-DR mAb L243 or by the anti-HLA-DR,-DP mAb IVA12 significantly (p < 0.05) increased the release of TNF-alpha by the EBV-B lymphoblastoid cell line JY . In contrast, the anti-HLA-DR mAb 2.06 or the superantigens staphylococcal exotoxin toxic shock syndrome toxin-1 and staphylococcal enterotoxin B that bind to HLA-DR,-DQ Ag did not affect the release of TNF-alpha by JY cells . The accumulation of TNF-alpha in the culture medium of JY cells peaked at 24 h, decreased thereafter, and was found to be dependent on the dose of mAb L243 or mAb IVA12 used to cross-link HLA class II Ag . mAb L243 or staphylococcal exotoxin toxic shock syndrome toxin-1 enhanced the spontaneous homotypic aggregation of JY cells and mediated a dose-dependent inhibition of JY cell proliferation . These phenomena were not mediated by TNF-alpha released in response to cross-linking of HLA class II Ag; polyclonal anti-TNF-alpha neutralizing antibody did not affect JY cell aggregation and the inhibition of JY cell proliferation mediated by mAb L243 . In contrast, TNF-alpha secreted by JY cells enhanced a nuclear factor-kB-like activity through the binding to the 75-kDa TNF-alpha receptor . These results demonstrate an additional role of HLA class II Ag as signal-transducing molecules regulating the production of bioactive TNF-alpha by EBV-B cells . The release of TNF-alpha after the triggering of HLA class II molecules could be relevant to different aspects of B cell biology and might play a role in the pathogenesis of human diseases in which antibodies cross-reactive to HLA class II Ag have been identified.

J Immunol, 1993 Nov 15, 151(10), 5840 - 55
Age-associated changes in binding of human B lymphocytes to a VH3-restricted unconventional bacterial antigen; Silverman GJ et al.; We have recently demonstrated that there is a site on Staphylococcal protein A (SpA) that interacts with B cell Ig receptors in a manner comparable with known T cell superantigens, because this binding specificity is restricted to Fab with VH3 H chains and most VH3 Ig bind SpA . In the present studies, SpA was used as a phenotypic marker for VH3 expression by human lymphoid cells . As expected, this Fab-mediated binding specificity was completely inhibited by certain VH3 antibodies but not by antibodies from other VH families . In multiparameter flow cytometric analyses, this binding activity was demonstrated to be highly prevalent among B cells (14 to 54%), and was more common among IgM-bearing B cells compared with IgG-bearing B cells . In all studies, Fab-mediated binding of SpA was uniformly expressed by a greater proportion of CD5-positive B cells than CD5-negative B cells . The proportion of B lymphocytes with this VH3-restricted binding capacity was found to undergo age-associated changes, because a large proportion of the peripheral B cells of neonates (mean +/- SD, 46.0 +/- 2.9%) bind this site, but two 10-mo-old subjects and older children had significantly lower binding levels (29.0 +/- 3.5%) that were the same as binding levels by adult peripheral B lymphocytes (30.2 +/- 3.3%) . In immunohistochemical studies, tonsilar B cells that bind this site on SpA were shown to be common in mantle zones and germinal centers of secondary follicles . We speculate that Fab-mediated SpA binding represents a fundamental and primitive binding capacity that is part of the human preimmune repertoire, and we discuss the implications for the observed age-dependent shift in Fab-mediated binding of SpA by peripheral blood B cells.

Dtsch Med Wochenschr, 1993 Nov 12, 118(45), 1636 - 40
{Pneumonia due to a rare atypical Mycobacterium in AIDS}; Huber W et al.; A 38-year-old man, HIV-positive for 6 years, developed fever and cough with deterioration in his general state . Chest radiography demonstrated an infiltration in the left upper lobe and computed tomography showed a septated cavity . Three bronchioalveolar lavages over 4 weeks recovered Klebsiella, Candida, Pseudomonas and Staphylococcus in the lavage fluid . Acid-fast rods were not found in any of the microscopic preparations . His clinical condition and the radiological findings deteriorated despite appropriate antibiotic administration . A further cavity occurred in the right upper lobe and the inflammatory infiltrations extended further . Although no acid-fast organism had been demonstrated, tuberculostatic treatment was begun (daily 300 mg isoniazid, 600 mg rifampicin, 900 mg streptomycin, 2 g pyrazinamide) . His general condition and the radiological findings rapidly improved . Four weeks after culturing the lavage fluid atypical Mycobacterium xenopi was isolated . This case illustrates the difficulty of diagnosing an atypical mycobacterial infection . It takes time and effort, but it is of great importance because up to 50% of patients with AIDS contract such infection . Early and appropriate treatment will significantly improve quality of life and life expectancy.

Biochemistry, 1993 Nov 9, 32(44), 11810 - 8
NMR strategy for determining Xaa-Pro peptide bond configurations in proteins: mutants of staphylococcal nuclease with altered configuration at proline-117; Hinck AP et al.; A general approach has been developed for configurational analysis (cis or trans) of Xaa-Pro peptide bonds in proteins . This approach, which entails selective 13C labeling of Xaa and Pro residues in the protein and isotope-edited NMR, has been applied to mutants of staphylococcal nuclease with suspected altered configurations of the Lys116-Pro117 peptide bond . The technique for monitoring proline configurations is based on differences in interproton distances between the H alpha of residue Xaa and the proline H delta or H alpha protons . Short (< 2.5 A) Xaa H alpha-Pro H delta interproton distances are diagnostic for the trans configuration, whereas short (< 2.5 A) Xaa H alpha-Pro H alpha interproton distances are diagnostic for the cis configuration . Biosynthetic incorporation of {alpha-13C}Xaa and {delta-13C}proline facilitates detection of trans Xaa-Pro peptide bonds, whereas incorporation of {alpha-13C}Xaa and {alpha-13C}proline facilitates detection of cis Xaa-Pro peptide bonds . Provided that the Xaa-Pro peptide bond is unique within the protein sequence, symmetric off-diagonal NOE cross peaks in the isotope-edited NOE spectrum allow for simultaneous chemical shift assignment and determination of the prolyl peptide bond geometry . We have used this technique to determine the predominant configuration of the Lys116-Pro117 peptide bond in recombinant V8 staphylococcal nuclease A (H124L) and two of its single amino acid mutants (D77A+H124L and G79S+H124L) . The results are consistent with conclusions reached on the basis of indirect arguments concerning changes in the chemical shifts of histidine 1H epsilon 1 NMR signals.(ABSTRACT TRUNCATED AT 250 WORDS)

Infect Immun, 1993 Nov, 61(11), 4937 - 9
Interleukin 10 protects mice against staphylococcal enterotoxin B-induced lethal shock; Bean AG et al.; We investigated the ability of interleukin 10 (IL-10) to protect mice against lethal shock induced by staphylococcal enterotoxin B (SEB) . Treatment of mice with IL-10 prevented the death of mice injected with SEB in a dose-dependent manner . IL-10-mediated protection was apparent when administered either prior to or concurrent with SEB but was less effective when administered following SEB injection . This observation indicates that IL-10 is capable of regulating T-cell activation in vivo.

Biull Eksp Biol Med, 1993 Nov, 116(11), 464 - 6
{The interrelationship of the protein content of the tissue of the submandibular salivary glands and the mucosa during the secretory cycle in acute inflammation of the oral soft tissues}; Mikhailov VV et al.; The Lowry method was used to estimated protein levels in the submaxillary salivary glands, oral mucosa and saliva during pilocarpine-induced and uninduced secretion in acute Staphylococcal inflammation of oral soft tissue . It has been shown that protein levels were unchanged in the salivary glands and oral mucosa in unstimulated and stimulated secretion following 2 hours . After 24 hours, they were also unchanged in the salivary glands and oral mucosa in unstimulated secretion, but in stimulated secretion the levels of protein were increased . It is concluded that in pilocarpine-induced secretion, there was increased defense of mucosal soft tissue and salivary gland tissue due to higher protein levels in the interstitial space.

J Infect, 1993 Nov, 27(3), 297 - 300
Covert multi-focal infective arthritis; Pitkin AD et al.; Six patients with pre-existing rheumatic joint disease presented with overwhelming septicaemia but without overt signs of joint inflammation . Joint aspirates demonstrated multifocal staphylococcal infective arthritis . Despite intensive care all six died from the infection or its immediate sequelae . The contrast between this clinical entity and classical infective arthritis, presenting with one or more swollen, tender joints, is discussed.

Bioconjug Chem, 1993 Nov-Dec, 4(6), 455 - 66
Preparation and characterization of conjugates of monoclonal antibodies and staphylococcal enterotoxin A using a new hydrophilic cross-linker; Akerblom E et al.; Conjugates between monoclonal antibodies recognizing human cancer cells and the superantigen staphylococcal enterotoxin A (mAb-SEA) represent a potential novel approach to tumor therapy . Such mAb-SEA conjugates direct T-cells to lyse colon carcinoma cells in vitro . The synthesis of mAb-SEA conjugates which were prepared by introducing thiol groups on SEA and iodoacetyl or maleimide groups on mAb forming a stable thioether linkage between SEA and mAb is described . A hydrophilic spacer, composed of repeated ethylene oxide units, was constructed to increase the distance between SEA and mAb, preserving biological activity of both proteins . The degree of modification of mAb with SEA was determined with SDS-PAGE . Variables influencing the composition of the conjugates and their effect on the tumor-cell cytotoxicity were studied and optimal conditions for the synthesis were established . Functionally active mAb-SEA conjugates were prepared from a panel of different mAb and T-cell-dependent cytotoxicity against several human cancer types including colon, ovarial, breast, and renal cancer was obtained . This suggests that mAb-SEA conjugates may be of value in the treatment of human neoplastic disease.

JPEN J Parenter Enteral Nutr, 1993 Nov-Dec, 17(6), 575 - 7
Staphylococcus saprophyticus sepsis related to total parenteral nutrition admixtures contamination; Llop JM et al.; The aim of this study was to report an outbreak of sepsis related to contamination of total parenteral nutrition (TPN) admixtures with Staphylococcus saprophyticus . A total of four patients developed fever after administration of contaminated TPN . Results of cultures of blood, catheter hubs and tips, and TPN admixtures are presented . The strain responsible for the outbreak was able to grow in vitro in two common TPN formulations.

Anasthesiol Intensivmed Notfallmed Schmerzther, 1993 Nov, 28(7), 404 - 14
{Infections caused by intravascular catheters . Etiopathogenesis--diagnosis--therapy--prevention}; Bach A et al.; Despite improvements in infection control measures, catheter-related infections represent a challenging problem in modern medicine . The difficulties in correctly diagnosing catheter-related infections and the necessity to remove the device in case of suspected infection require preventive measures in the first place . Most authors stress the importance of strict aseptic catheter management . Nevertheless, there may still be a high incidence of catheter-related infections . Moreover, this problem is potentiated by the increasing use of intravascular devices . The current infection rates may be reduced by instituting novel preventive measures, e.g., decontamination of carriers using the anti-staphylococcal agent mupirocin . Another approach aims at inhibiting the adhesion of bacteria to intravascular catheters by modifying these catheters with antimicrobial agents . Newer studies show that impregnation of catheters with the antiseptic substances silver-sulphadiazine and chlorhexidine is effective in reducing bacterial colonisation of the catheters . A pilot study on intensive-care patients demonstrated a significant reduction in catheter-related infections and bacteraemia by impregnated catheters . This novel approach may reduce the incidence of catheter-related infections below the level which could be achieved by employing all current preventive measures.

Clin Infect Dis, 1993 Nov, 17(5), 871 - 6
Endocarditis due to Staphylococcus lugdunensis: report of 11 cases and review; Vandenesch F et al.; Staphylococcus lugdunensis is a recently described coagulase-negative staphylococcus that has been associated with human infections, including nine reported cases of infective endocarditis . The present study describes 11 other cases of infective endocarditis caused by this organism . The infection occurred in patients whose mean age was 61 years and was community-acquired in most cases . A preexisting cardiac abnormality was present in eight patients . Three of the 11 infections involved prosthetic valves . Ten strains were susceptible to penicillin . The destructive course of the infection, the need for valve replacement, and the high mortality suggest that S . lugdunensis causes a virulent form of endocarditis.

J Immunother, 1993 Nov, 14(4), 279 - 85
In vivo antitumor efficacy of tumor-draining lymph node cells activated with nonspecific T-cell reagents; Shu S et al.; Progressive growth of immunogenic murine tumors elicits a tumor-specific but functionally deficient T-cell immune response in the draining lymph nodes . These T cells, referred to as "pre-effector" cells could be induced in vitro to differentiate into mature immune effector cells, capable of mediating the regression of established metastases . Initially, tumor cells were used to stimulate the in vitro maturation of pre-effector cells . Alternatively, we found that pre-effector cells could be activated by sequential stimulation with anti-CD3 and interleukin-2 in the absence of tumor cells . In adoptive immunotherapy, these activated cells mediated therapeutic effects that were exquisitely specific to the tumor that triggered the pre-effector cell response in vivo . Since the anti-CD3 interaction with T cells is polyclonal, the activated lymph node cell population must also contain a significant number of T cells that do not have tumor specificity . In an attempt to selectively activate tumor-sensitized pre-effector cells, we recently utilized superantigenic bacterial toxins as T-cell stimuli for effector cell generation . Superantigens combine with major histocompatibility class II molecules to form the ligands that stimulate T cells bearing distinct T-cell receptor V beta elements . Lymph node cells draining the MCA 205 sarcoma stimulated with staphylococcal enterotoxins A (SEA), B (SEB), or C2 (SEC2) resulted in selective expansions of V beta 3 and 11, V beta 3 and 8, or V beta 8.2 T cells, respectively . Adoptive immunotherapy experiments revealed that SEB- and SEC2-, but not SEA- stimulated cells, mediated tumor-specific eradication of pulmonary metastases.(ABSTRACT TRUNCATED AT 250 WORDS)

Radiol Med (Torino), 1993 Nov, 86(5), 587 - 94
{Study of spondylodiscitis with magnetic resonance . Use of gadolinium-DTPA}; Duca S et al.; Eighteen patients suffering from spondylodiscitis were examined with MRI and 22 pathologic levels were identified: 1 cervical, 6 thoracic and 15 lumbosacral . As for etiology, 4 cases were tubercular, 3 strepto-staphylococcal, 3 brucellar 1 strepto-bacteroides and 11 of unknown origin . Five patients underwent MR follow-up 4-9 months after the clinical onset . SE T1- and T2-weighed sequences were always performed and 11 patients, with 13 pathologic levels, also underwent SE T1-weighted sequences with i.v . Gd-DTPA administration . No correlation could be made between the signal intensity of the involved vertebral bodies and disks and etiology . On SE T1-weighted sequences 91% of the vertebral bodies were hypointense, whereas the intervertebral disks were hypointense in 55% of cases and isointense in 45% . On SE T2-weighted sequences, the vertebrae appeared hyperintense in 65% of the cases while the disks were hyperintense in 55% and isointense in 41% . After Gd-DTPA injection signal intensity increased in 100% of cases, both at the body and at the disk . In 6 cases an inflammatory infiltration of the intracanalar structures was found, whose identifications was possible, in 4 cases, only after contrast medium injection . In the follow-up of 5 cases at 4-9 months the vertebral bodies remained hypointense in 3 cases on T1-weighted sequences, while in 2 cases signal intensity tended to normalize . Signal normalized in 4 cases on T2-weighted sequences . In 2 follow-up examinations disk structures were never depicted, neither on T1- nor on T2-weighted sequences . To conclude, T1-weighted sequences appear to be more sensitive than T2-weighted sequences to demonstrate inflammatory processes in the vertebral bodies, while the two sequences are equivalent to evaluate the disks . Gadolinium-enhanced T1-weighted sequences were more sensitive than the T1- and T2-weighted ones, especially to assess the extent of inflammatory processes into the spinal canal and to evaluate their persistence . The authors suggest the use of unenhanced and enhanced SE T1-weighted sequences only at least in the follow-up of spondylodiscitis.

J Cell Biochem, 1993 Nov, 53(3), 198 - 205
Nitric oxide production from a macrophage cell line: interaction with autologous and allogeneic lymphocytes; Isobe K et al.; The indirect stimulation of macrophages to produce nitrite was examined by using the macrophage cell line J774.J774 spontaneously produced nitrite, when cultured at high concentration . J774 cultured in low concentration (< 10(4) cells in 100 microliters) barely produced nitrite . J774 cultured in low concentration produced a large amount of nitrite by the co-culture of nonadherent spleen cells or nonadherent peritoneal exudate cells, which were stimulated with con A, anti-CD3, or staphylococcal enterotoxin A . J774 (BALB/c derived: H-2d) cultured with either syngeneic (BALB/c) or allogeneic (B6; H-2b B10BR; H-2k) nonadherent lymphocytes, which were stimulated with conA or anti-CD3, produced nitric oxide . However, J774 produced nitric oxide by stimulation with SEA only when co-cultured with SEA-reactive T lymphocytes . Peritoneal exudate cells from mice, which did not proliferate by the stimulation of conA or anti-CD3, proliferated well by the addition of L-arginine homologue, NG-monomethyl-L-arginine . The proliferation of nonadherent peritoneal exudate cells stimulated with conA or anti-CD3 was suppressed by the addition of peritoneal macrophages . This suppression was abolished by the addition of NG-monomethyl-L-arginine.

Biophys Chem, 1993 Nov, 48(1), 39 - 48
Intramolecular dynamics in the environment of the single tryptophan residue in staphylococcal nuclease; Demchenko AP et al.; The dipole relaxational dynamics in the environment of a single tryptophan residue Trp-140 in staphylococcal nuclease was studied by time-resolved (multi-frequency phase-modulation) spectroscopy and selective red-edge excitation . The long-wavelength position of the fluorescence spectrum (at 343 nm) and the absence of red-edge excitation effects at 0 and 20 degrees C indicate that this residue is surrounded by very mobile protein groups which relax on the subnanosecond time scale . For these temperatures (0-20 degrees C) the steady-state emission spectra did not show the excitation-wavelength dependent shifts (red-edge effects) for excitation wavelengths from 295 to 308 nm; however, the anisotropy decay rate is slow (tens of nanoseconds) . This suggests that the spectral relaxation is due to mobility of the surrounding groups rather than the motion of the tryptophan itself . The motions of the tryptophan surrounding are substantially retarded at reduced temperatures in viscous solvent (60% glycerol) . The temperature dependence of the difference in position of fluorescence spectra at excitation wavelengths 295 and 305 nm demonstrate the existence of red-edge effect at sub-zero temperatures, reaching a maximum value at -50 degrees C, where the steady-state emission spectrum is shifted to 332 nm . The excitation and emission wavelength dependence of multi-frequency phase-modulation data at the half-transition point (-40 degrees C) demonstrates the existence of the nanosecond dipolar relaxations . At -40 degrees C the time-dependent spectral shift is close to monoexponential with the relaxation time of 1.4 ns.

Transplantation, 1993 Nov, 56(5), 1072 - 6
The effect of rejection and graft-versus-host disease on small intestinal microflora and bacterial translocation after rat small bowel transplantation; Price BA et al.; Bacterial translocation and the development of sepsis after small bowel transplantation may be promoted by immunological damage to the intestinal mucosa or by quantitative and qualitative changes in intestinal microflora . This study assessed the effects of rejection, graft-versus-host disease (GVHD) and immunosuppression on intestinal microflora and bacterial translocation after heterotopic rat small bowel transplantation . Isografts, allografts with and without CsA immunosuppression, and the semi-allogeneic parent to the F1 hybrid GVHD model were studied . Intestinal microflora in graft and host loops and bacterial translocation to host organs and the graft mesenteric lymph node were determined . Bacterial colonies were counted and individual colonies identified using API 20E nutrient and fermentation indicator techniques . Colony counts in isografts and allografts were significantly higher than in the native intestine, whereas there was a massive overgrowth in the native intestine in the GVHD group . The species profile for the host and graft loops was similar in animals that had received isografts, allografted animals receiving CsA, and animals undergoing GVHD . However, there was a large increase in Staphylococcus epidermidis in animals with rejection . Bacterial translocation was not detected in isografted animals, but was observed in all other animal groups, with S . epidermidis being the most prevalent organism . These findings demonstrate that rejection and GVHD are associated with shifts in intestinal microflora toward potentially pathogenic organisms and that bacterial translocation into recipient tissues poses a major threat for the development of sepsis.

Ann Thorac Surg, 1993 Nov, 56(5), 1063 - 8
A fifteen-year wound surveillance study after coronary artery bypass; Slaughter MS et al.; Wound infections after coronary artery bypass operations have been continuously monitored at the Minneapolis Veterans Affairs Hospital for 15 years . All patients were followed up for 30 days . From 1977 to 1991, 2,402 coronary artery bypass operations were performed, and wound infections developed in 125 (5%) patients . There were 71 (3%) chest infections of which 33 (1.4%) were major and 38 (1.6%) superficial . Greater than 94% of these grew only a single organism, of which 74% were Staphylococcus species . There were 63 (2.6%) leg wound infections . More than 50% of these grew multiple organisms, of which 68% were enteric in origin . Nine (0.4%) patients had simultaneous chest and leg infections . Wound infections were diagnosed an average of 15.3 +/- 6.7 (range, 4 to 30) days postoperatively, with 50% occurring after discharge from the hospital . Of 14 variables evaluated by multivariate logistic regression analysis, only steroids (p = 0.005) and diabetes (p = 0.003) were identified as independent risk factors for wound infections . Patients taking steroids or with diabetes tended to have chest infections, whereas obese patients tended to have more leg infections (p = 0.08) . During an interval in the surveillance program, a trend toward increasing infections was identified and successfully reversed.

Jpn Circ J, 1993 Nov, 57(11), 1080 - 8
Surgical treatment of active infective endocarditis--early and late results of active native and prosthetic valve endocarditis; Abe T et al.; The purpose of this study was to determine the clinical predictors of active infective endocarditis in 45 cases we treated between January 1971 and August 1991 (30 native valve endocarditis (NVE) and 15 prosthetic valve endocarditis (PVE) . The indication of surgery in 45 patients was progressive congestive heart failure (CHF), septicemia and systemic embolization . The aortic valve was involved in 24 (53%) of 45 patients (13 of 30 NVE and 11 of 15 PVE) and there was significantly higher early mortality in aortic PVE (36%) than in aortic NVE (8%) . The 9 patients with severe cardiac failure (NYHA Class V) before surgery were associated with a significantly higher incidence of early mortality (5/9 = 56%) than those in Class III (2/14 = 14%) and Class IV (3/18 = 17%) . We concluded that aortic valve infection is more prevalent than mitral valve infection and is more often associated with staphylococcus infection, including abscess formation . Early surgical intervention should be performed despite the risk of cardiac failure and extensive infection.

J Exp Med, 1993 Nov 1, 178(5), 1693 - 700
Protease inhibitors selectively block T cell receptor-triggered programmed cell death in a murine T cell hybridoma and activated peripheral T cells; Sarin A et al.; The hypothesis that cytoplasmic proteases play a functional role in programmed cell death was tested by examining the effect of protease inhibitors on the T cell receptor-mediated death of the 2B4 murine T cell hybridoma and activated T cells . The cysteine protease inhibitors trans-epoxysuccininyl-L-leucylamido-(4-guanidino) butane (E-64) and leupeptin, the calpain selective inhibitor acetyl-leucyl-leucyl-normethional, and the serine protease inhibitors diisopropyl fluorophosphate and phenylmethylsulfonyl fluoride, all showed dose-dependent blocking of the 2B4 death response triggered by the T cell receptor complex and by anti-Thy-1 . These protease inhibitors enhanced rather than inhibited IL-2 secretion triggered by T cell receptor cross-linking, showing that they did not act by preventing signal transduction . Growth inhibition induced by cross-linking the 2B4 T cell receptor, measured by inhibition of thymidine incorporation, was not generally blocked by these protease inhibitors . All five of these protease inhibitors enhanced rather than blocked 2B4 cell death triggered by dexamethasone, an agent previously shown to have a death pathway antagonistic with that of the TCR . 2B4 cytolysis by the cytotoxic agents staphylococcal alpha-toxin and dodecyl imidazole, and that caused by hypotonic conditions, was not significantly affected by the five protease inhibitors tested . The selected protease inhibitors blocked both the apoptotic nuclear morphology changes and DNA fragmentation induced by T cell receptor cross-linking, and enhanced both these properties induced by dexamethasone in 2B4 cells . The T cell receptor-induced death of activated murine lymph node T cells and human peripheral blood CD4+ T cells was blocked by both cysteine and serine protease inhibitors, showing that the protease-dependent death pathway also operates in these systems.

J Infect Dis, 1993 Nov, 168(5), 1202 - 10
Interleukin-8 production by human peritoneal mesothelial cells in response to tumor necrosis factor-alpha, interleukin-1, and medium conditioned by macrophages cocultured with Staphylococcus epidermidis; Betjes MG et al.; Patients treated with continuous ambulatory peritoneal dialysis (CAPD) may suffer from recurrent peritonitis episodes caused by Staphylococcus epidermidis . Early recruitment of granulocytes from the peripheral blood is important for the peritoneal antibacterial defense of CAPD patients . In this study, human peritoneal mesothelial cells were shown to produce high levels of interleukin-8 (IL-8) in response to IL-1 beta and tumor necrosis factor-alpha (TNF alpha) but not lipopolysaccharide or S . epidermidis . Coculture of peritoneal macrophages with S . epidermidis induced high levels of IL-1 alpha, IL-1 beta, and TNF alpha in 24-h-conditioned medium . Preincubation of this medium with anti-TNF alpha, anti-IL-1 alpha, or anti-IL-1 beta partially blocked stimulation of IL-8 production by mesothelial cells . Added together, these antibodies abolished IL-8 production to a level just above background . Migration of granulocytes to the stimulated mesothelial cell-conditioned medium could be totally blocked with rabbit polyclonal anti-IL-8 antibody . Thus, mesothelial cells are important for the recruitment of granulocytes into the peritoneal cavity.

J Bacteriol, 1993 Nov, 175(22), 7495 - 9
Cloning, sequencing, and characterization of the gene encoding the class I fructose-1,6-bisphosphate aldolase of Staphylococcus carnosus; Witke C et al.; fda from Staphylococcus carnosus TM300, encoding the class I fructose-1,6-bisphosphate aldolase, was cloned in Escherichia coli and sequenced . The 888-nucleotide open reading frame encoding a protein with an M(r) of 32,855 had an E . coli-like promoter sequence . Plasmids containing fda complemented E . coli NP315 (Fda-) . Expression of fda in S . carnosus led to a six- to eightfold increase in aldolase production and activity; low levels of glucose in the growth medium stimulated activity.

Eur J Immunol, 1993 Nov, 23(11), 2927 - 31
L1 adhesion molecule on mouse leukocytes: regulation and involvement in endothelial cell binding; Hubbe M et al.; L1 is a cell surface glycoprotein of the immunoglobulin superfamily which was initially shown to mediate adhesion between neural cells . Recently we have reported that L1 is expressed by bone marrow cells and the majority of mature lymphocytes (Kowitz et al., Eur . J . Immunol . 1992 . 22: 1199-1205) . To analyze the function of L1 on leukocytes we studied its regulation following cell activation . In vitro activation of B lymphocytes with lipopolysaccharide or T lymphocytes with phorbol 12-myristate 13-acetate/Ca2+ ionophore, concanavalin A or anti-CD3 monoclonal antibody as well as in vivo activation of V beta 8+ T cells with staphylococcal enterotoxin B (SEB) revealed a down-regulation of L1 within 48 h . A rapid loss of L1 expression was seen when mouse neutrophils were activated with PMA alone . This rapid loss paralleled the shedding of L-selectin . We also studied a possible role of L1 in the binding of leukocytes to endothelial cells . ESb-MP lymphoma cells with a high expression of L1 (L1hi) could bind to bend3 endothelioma cells without prior activation with inflammatory cytokines . The interaction was inhibited by anti-L1 antibodies . In contrast, ESb-MP cells with low L1 expression (L1lo) were only marginally bound . Latex beads coated with affinity-isolated L1 antigen were also able to bind to the endothelioma cells in a specific fashion . The binding of ESb-MP lymphoma cells required Ca2+ and Mg2+ ions and was sensitive to cold temperature . Since the endothelioma cells did not express L1 the binding mechanism studied here is distinct from the established L1-L1 homotypic interaction . It is possible that the novel L1-mediated adhesion pathway involves an unidentified ligand and could play a role in leukocyte migration.

Chemotherapy, 1993 Nov-Dec, 39(6), 394 - 9
Killing kinetics of four quinolones against gram-positive cocci; Canton E et al.; Killing kinetics of four fluoroquinolones against Staphylococcus species were determined during the first 5 h of incubation in the presence of drug concentrations ranging from the MIC to 1,024 micrograms/ml . Additionally, the relationship between killing rate and drug concentration was established . Sparfloxacin and temafloxacin were the most active quinolones assayed with greater lethal rates than ciprofloxacin and norfloxacin . The relation was biphasic with a decrease of at least 1 log10 c.f.u./ml at high drug concentrations with respect to that obtained at the optimal bactericidal concentration for all quinolone-microorganism combinations tested.

Surg Gynecol Obstet, 1993 Nov, 177(5), 504 - 6
Diagnosis and therapy of subclinically infected prostheses; Parsons CL et al.; We believe 5 to 7 percent of prosthetic devices are "subclinically" infected by Staphylococcus epidermidis . These infections are manifested by chronic pain, migration and late extrusion of the devices . To examine this problem, we cultured penile and mammary prostheses . For the experimental arm, we cultured painful penile and mammary prostheses that were being removed because of symptoms (pain) . For patients in a control group, we cultured penile prostheses being replaced because of mechanical failure (no pain) and mammary tissue expanders that were temporarily installed . Actual parts of the device were cultured in Trypticase Soy Broth . There were 14 and 12 painful penile and mammary prostheses, 13 and ten, respectively, were cultured positive, for an infection rate of 88 percent . The primary organism identified was S . epidermidis . The nonpainful penile prostheses (zero of five and three of 22 mammary prostheses) grew S . epidermidis . The differences were highly significant (p < 0.001), suggesting that the painful prosthesis is infected . In an attempt to resolve the problem of the painful prosthesis, ten prosthesis were removed and exchanged for new devices . Patients received preoperative and postoperative antibiotics . All ten had positive cultures and nine of ten were successfully exchanged (no pain).

Pediatr Med Chir, 1993 Nov-Dec, 15(6), 579 - 82
{Staphylococcal infection in the newborn: teicoplanin therapy}; Fanos V et al.; Infections caused by Gram-positive bacteria, particularly in neonatal patients, have increased dramatically over the past 10 years . In the present study 19 newborns (7 at term, 12 preterm) with proven staphylococcal infection were treated with teicoplanin, after a previous ineffective antibiotic treatment (amikacin+oxacillin or third-generation cephalosporin) . Bacterial eradication and clinical cure were achieved in all neonates . No adverse events related to the drug occurred . No significant change was observed in serial biochemical and hematological tests . Our results suggest that teicoplanin is highly effective and safe in neonatal staphylococcal infections.

Khirurgiia (Mosk), 1993 Nov, (11), 10 - 5
{The use of xenogeneic splenic perfusates for treating suppurative-septic diseases}; Makarov AA et al.; It was shown in experiments on a model of fatal staphylococcal sepsis in 200 mice and 15 dogs that the perfusate of a pig's spleen obtained by perfusion of the isolated organ with a dextran solution (rheopolyglucin, polyglucin) is capable of preventing the animals' death . Intravenous infusion of 400-500 ml of a xenospleen perfusate at an interval of 1-3 days, which was included in the complex of postoperative treatment of 45 patients with destructive diseases of the abdominal organs complicated by peritonitis and sepsis, contributed to reduction of lethality and the terms of recovery . It is shown that the main effect, besides detoxification, is based on immunomodulation at the cost of biologically active substances produced by the cells of a xenospleen and contained in the perfusate . The best results were produced with the use of the perfusate of a xenospleen in the early periods after radical operation and thorough cleansing of the source of the infection.

Eur J Clin Microbiol Infect Dis, 1993 Nov, 12(11), 866 - 8
Variable fixation of staphylococcal slime by different histochemical fixatives; Baldassarri L et al.; A variety of histochemical fixatives were used to compare the fixation of bacterial films produced by a standard slime-producing strain of Staphylococcus epidermidis on plastic tissue culture plates . Some reagents were completely ineffective in fixing the slime layer, whereas others gave variable results . The best alternative to the fixative of the reference method, the potentially explosive Bouin's reagent, was air drying.

Mikrobiol Z, 1993 Nov-Dec, 55(6), 57 - 62
{The antibacterial effects of homologous interferons in an experimental staphylococcal infection}; Fil'chakov IV et al.; Homologous interferons (IF) of the 1st and 2nd types are studied for their effect on the course of experimental staphylococcal infection . A model of intracutaneous infection of animals is used . Survival of mice, dynamics of the agent elimination from the organism, functional activity of phagocytes in dynamics of the infectious process during IF administration are studied . Only preparations of natural IF are found to possess a protective effect . The recombinant gamma-IF does not prevents from the mouse death and exerts no effect on the dynamics of elimination of agents from the organism.

J Biotechnol, 1993 Nov, 31(2), 225 - 32
Expression in Escherichia coli and in vitro processing of HIV-1 p24 fusion protein; Marczinovits I et al.; Recombinant HIV-1 p24/p25 gag proteins were obtained from Escherichia coli using a cleavable fusion strategy . The fusion protein contains 280 amino acid residues of staphylococcal Protein A and 317 amino acid residues of p24/p25 flanking with the recognition/cleavage sequences for HIV protease . Fusion protein expressed under the control of lambda phage promoter PR was purified by IgG-Sepharose affinity chromatography . The p24/p25 part of the fusion protein was released by recombinant HIV protease in vitro . After a second IgG-Sepharose affinity chromatography, the purified p24/p25 proteins were obtained in milligram quantities . The HIV-1 p24/p25 protein displayed antigenicity similar to those of native counterparts confirmed by Western blot assays and the Abbott antigen test.

Biochemistry, 1993 Oct 19, 32(41), 11022 - 8
Hydrogen exchange in unligated and ligated staphylococcal nuclease; Loh SN et al.; The exchange kinetics of over 70% of the 143 backbone amide hydrogens in staphylococcal nuclease H124L (nuclease H124L), both in its unligated state and in its ternary complex with Ca2+ and thymidine 3',5'-bisphosphate, have been quantified by nitrogen-15 resolved proton nuclear magnetic resonance spectroscopy . Protection factors for the slowly exchanging hydrogens in unligated nuclease H124L at 37 degrees C and pH 5.5 were found to vary by over one order of magnitude . This range of protection factors has been interpreted in the framework of global and local structural fluctuations . The three most highly protected hydrogens (K24, L25, M26) map to strand 2 of the central five-stranded beta-barrel . The free energy change for the opening reaction which exposes these hydrogens to the solvent (delta G(degree)op) was calculated from the exchange rates in the native and denatured states, the latter values being estimated from model peptide exchange studies {Molday, R . S., Englander, S . W., & Kallen, R . G . (1972) Biochemistry 11, 150-158} . Close agreement was found between delta G(degree)op and delta G(degree)u, the free energy change of unfolding as measured by urea denaturation experiments . Exchange of these hydrogens thus appears to occur via global unfolding of the protein . One region exhibited somewhat lower protection factors: it mapped to the C-terminal portions of helix 2 and helix 3 and to part of the intervening segment . This region has been identified as a minor hydrophobic domain of nuclease {Shortle, D., Stites, W . E., & Meeker, A . K . (1990) Biochemistry 29, 8033-8041}.(ABSTRACT TRUNCATED AT 250 WORDS)

J Immunol, 1993 Oct 15, 151(8), 4362 - 70
Prevention of autoimmune type I diabetes by CD4+ suppressor T cells in superantigen-treated non-obese diabetic mice; Kawamura T et al.; The development of autoimmune type I diabetes in the NOD mouse appears to be controlled by both genetic and environmental factors . This investigation was initiated to determine whether exogenous superantigens, as environmental factors, can influence the development of diabetes . Several staphylococcal enterotoxins (SE) (SEA, SEC1, SEC2, or SEC3), which are known superantigens, were injected i.v . into female NOD mice at 4 and 10 wk of age . At 32 wk of age, the incidence of diabetes in the SE-treated mice ranged from 6 to 12.5%; this was significantly lower than that of mice treated with PBS--64% . There was no significant difference in effectiveness among the various SE used . SE induced a modest decrease in T lymphocytes bearing specific V beta TCR 2 wk after injection, but this effect did not persist past 4 wk . To elucidate the mechanism of the SE effect, suppressor activity in SE-treated mice was evaluated . Splenocytes from SE-treated mice inhibited the transfer of diabetes by splenocytes from acutely diabetic NOD mice when injected into irradiated young NOD mice; only 10% became diabetic . In contrast, 83% of the mice receiving splenocytes from PBS-treated control mice became diabetic . Suppressor activity of splenocytes from SE-treated mice was diminished by the depletion of CD4+ T cells, but not by the depletion of CD8+ T cells, indicating that the suppressor cells belonged to the CD4+ T class of lymphocytes . On the basis of these observations, we conclude that exogenous superantigens activate CD4+ suppressor T cells, leading to the prevention of autoimmune type I diabetes in NOD mice.

Cell Immunol, 1993 Oct 15, 151(2), 467 - 73
Immobilized staphylococcal enterotoxin A is sufficient to induce T cell proliferation; Rust CJ et al.; We investigated the role of HLA-DR molecules in T cell stimulation by staphylococcal enterotoxin A (SEA) . Previous results with immobilized purified HLA-DR preincubated with peptide showed that peptide-specific T cell clones were able to bind to and proliferate in response to purified HLA-DR/peptide complexes in the absence of antigen presenting cells . We report here that two human T cell clones (1 alpha beta and 1 gamma delta T cell clone) and a murine T cell hybridoma were each activated by immobilized purified HLA-DR4Dw4 preincubated with SEA . Furthermore, immobilized SEA in the absence of HLA-DR4Dw4 also stimulated the human T cell clones . The proliferative response of the human T cell clones was inhibited by CD3-reactive monoclonal antibodies, indicating that the T cell receptor (TCR)/CD3 reacts with SEA . These observations suggest that the HLA-DR in the complex functions only to immobilize SEA and that an interaction between the TCR and HLA-DR is not necessary for SEA-driven T cell stimulation . Finally, the assays described here could provide a method for defining and distinguishing the SEA binding sites for MHC class II and TCR.

Structure, 1993 Oct 15, 1(2), 121 - 34
NMR analysis of the residual structure in the denatured state of an unusual mutant of staphylococcal nuclease; Shortle D et al.; BACKGROUND: Staphylococcal nuclease is a well-developed model system for analyzing the effects of mutations on protein folding and stability . Substitution of glycine 88 with valine (Gly88Val) destabilizes staphylococcal nuclease by 1.0 kcal mole-1 and reduces its sensitivity to the denaturant guanidine hydrochloride, a phenomenon which may indicate an increase in residual structure in the denatured state . To assess its effects on denatured state structure, the Gly88Val mutation was incorporated into a 136 residue nonsense fragment which has been developed as a model of the wild type denatured state . RESULTS: Application of two- and three-dimensional NMR spectroscopy to the Gly88Val fragment uniformly labeled with 15N and 13C has led to the assignment of 93 of the 136 residues . Comparison of chemical shifts of backbone resonances to those of wild type native nuclease, analysis of the secondary shifts of the assigned resonances and nuclear Overhauser effects involving backbone protons indicate that, unlike the wild type fragment, most if not all of the five-stranded beta-barrel structure persists in this denatured state . CONCLUSION: One major effect of the Gly88Val mutation is to perturb the cooperative breakdown of the folded conformation, leading to a denatured state which is both more ordered and more stable than that formed by the wild type sequence . Since the equilibrium between the native and denatured states depends on the free energy difference between them, stabilization of the denatured state by the Gly88Val mutation indirectly destabilizes the native state.

Nature, 1993 Oct 14, 365(6447), 642 - 4
Induction of relapsing paralysis in experimental autoimmune encephalomyelitis by bacterial superantigen; Brocke S et al.; The role of infection in the pathogenesis of clinical relapses that occur in most autoimmune diseases, including multiple sclerosis, remains to be established . Experimental autoimmune encephalomyelitis (EAE) serves as a model for multiple sclerosis, with episodes of relapsing paralysis . In certain strains of mice, T-lymphocytes expressing the V beta 8 T-cell receptor (TCR) engage the amino-terminal epitope Ac1-11 of myelin basic protein, leading to EAE . The bacterial superantigen staphylococcal enterotoxin B (SEB) activates V beta 8-expressing T cells . Here we show that after immunization with Ac1-11, or after transfer of encephalitogenic T-cell lines or clones reactive to Ac1-11, SEB induces exacerbation or relapses of paralytic disease in mice that are in clinical remission following an initial episode of paralysis, and triggers paralysis in mice with subclinical disease . Tumour necrosis factor has a critical role in the mechanism underlying SEB-induced exacerbation of disease, because anti-tumour necrosis factor antibody given in vivo delays the onset of paralysis triggered by SEB . On reactivation of autoaggressive cells through their T-cell receptor, superantigens may induce clinical relapses of autoimmune disease.

Biochemistry, 1993 Oct 5, 32(39), 10359 - 70
Mutations can cause large changes in the conformation of a denatured protein; Flanagan JM et al.; Deletion of 13 amino acids from the carboxyl terminus of staphylococcal nuclease (WTSNase delta) results in a denatured, partially unfolded molecule that lacks significant persistent secondary structure but is relatively compact and monomeric under physiological conditions {Shortle & Meeker (1989) Biochemistry 28, 936-944; Flanagan et al . (1992) Proc . Natl . Acad . Sci . U.S.A . 89, 748-752} . Because of these and other properties of the SNase delta polypeptide, it is a useful model system for investigating the conformation of the denatured state of a protein without using extreme temperature or solvent conditions . Moreover, since the modification is a carboxyl-terminal deletion, SNase delta may also resemble a transient state of the polypeptide chain as it emerges from a ribosome prior to its folding . In the present study, we have examined the sizes and conformations of mutated forms of SNase delta, using small-angle X-ray scattering and circular dichroism spectroscopy . Seven mutated forms were studied: four with single substitutions, two with double substitutions, and one triple substitution . When present in the full-length SNase, each of these mutated forms exhibited unusual behavior upon solvent or thermal denaturation . In the case of the truncated form (SNase delta), the small-angle scattering curves of the mutated forms fall into two classes: one resembling the scattering curve of compact native nuclease and the other having features consistent with those expected for an expanded coil-like polymer . In contrast, the scattering curve of WT SNase delta exhibits features intermediate between those observed for globular proteins and random polymers . The amino acid substitutions that gave rise to compact, native-like versions of SNase delta were all of the m--type (m-substitutions are predicted to decrease the size of the denatured state) . Those which gave rise to versions of SNase delta that were more extended and coil-like than WT SNase delta were of the m+ type (m+ substitutions are predicted to increase the size of the denatured state) . Estimates of the residual secondary structure present in WT SNase delta, as well as both the m+ and m-substituted versions of SNase delta, as determined by CD, suggest that the formation of secondary structure and compaction of the polypeptide chain occur concurrently . Our results show that single amino acid substitutions can radically alter the conformational distribution of a partially condensed polypeptide chain.(ABSTRACT TRUNCATED AT 400 WORDS)

Mol Immunol, 1993 Oct, 30(14), 1279 - 85
The interaction between different domains of staphylococcal protein A and human polyclonal IgG, IgA, IgM and F(ab')2: separation of affinity from specificity; Ljungberg UK et al.; Binding properties of staphylococcal protein A (SpA) to different human immunoglobulins have been investigated . In this analysis, intact SpA as well as SpA-derived fragments containing one to five IgG-binding domains of different compositions, were used . The affinity binding constants of the different proteins to human polyclonal IgG, IgA, IgM and F(ab')2-fragments as well as their binding capacity to the immunoglobulin molecules were determined . The results show that although all the proteins bound to IgG, regardless of size or composition, the binding strength differed significantly . Proteins containing five domains have a stronger affinity for IgG than those containing one or two . There were no marked differences in binding strength between different domains . However, the binding ability to IgA and IgM showed a marked difference between the various SpA-derived proteins of different compositions . This discrepancy was correlated to differences in their relative binding properties to isolated F(ab')2-fragments of IgG . Hence, we conclude that the binding affinity is mainly affected by the number of domains, whereas the binding specificity is to a large extent determined by which domains are selected.

Eur J Immunol, 1993 Oct, 23(10), 2696 - 9
Staphylococcal enterotoxin B up-regulates interleukin-2 receptor beta chain expression on tonsillar B cells; Franz A et al.; The superantigen staphylococcal enterotoxin B (SEB) selectively up-regulates the interleukin-2 receptor (IL-2R) beta chain (p70) without up-regulating the IL-2R alpha chain (CD25) on a human tonsillar B cell population depleted of T cells . This action of SEB, probably mediated by binding to major histocompatibility complex class II, renders B cells sensitive to T cell-derived IL-2 and is sufficient for induction of vigorous DNA synthesis with low concentrations of IL-2 . This explains one of the mechanisms by which bacterial superantigens activate large numbers of B cells and may reflect a similar mechanism operative in cognate helper T cell/B cell interactions.

Eur J Immunol, 1993 Oct, 23(10), 2682 - 6
Complementarity-determining region 2 is implicated in the binding of staphylococcal protein A to human immunoglobulin VHIII variable regions; Randen I et al.; Staphylococcal protein A (SPA) has two distinct binding sites on human immunoglobulins . In addition to binding to the Fc region of most IgG molecules, an "alternative" binding site has been localized to the Fab region of human immunoglobulins encoded by heavy chain variable gene segments belonging to the VHIII family . Comparison of amino acid sequences of closely related SPA-binding and -non-binding proteins suggested that VHIII-specific residues in the second complementarity-determining region (CDR2) were likely responsible for SPA binding activity . Site-directed mutagenesis of a single amino acid residue in CDR2 converted an IgM rheumatoid factor which did not bind SPA to an SPA binder . These findings, therefore, locate a critical site involved in SPA binding to the CDR2 of human immunoglobulins encoded by VHIII family gene segments.

J Infect Dis, 1993 Oct, 168(4), 897 - 903
A porcine model of Staphylococcus epidermidis catheter-associated infection; McDermid KP et al.; The suitability of using catheterized, partially nephrectomized (uremic) pigs to study catheter-associated infection in peritoneal dialysis was investigated . In some pigs, an inoculum of 10(9) cfu of Staphylococcus epidermidis ATCC 35984 was deposited around the catheter exit site and the organism was allowed to colonize over 21 days . The strain was recoverable from tissues and catheter samples at various locations along the catheter tract from inoculated pigs at postmortem examination . Uninoculated control catheters were colonized to a significantly lesser degree and by various other staphylococcal species . Immune response by inoculated pigs toward catheter-associated bacteria was indicated by a significant increase in serum antistaphylococcal IgG concentration and an increased percentage of peripheral polymorphonuclear leukocytes . Uremia had no significant effect on serologic response . Immunoblotting against S . epidermidis lysostaphin-extracted proteins showed that although incubation with inoculated group antisera produced more intense banding and reacted to a wider range of protein than did antisera from uninoculated controls, common antigenic proteins among the groups were found.

J Immunol, 1993 Oct 1, 151(7), 3597 - 603
V-region-mediated binding of human Ig by protein A; Ibrahim S et al.; The Fab-mediated "alternative" binding of Ig by staphylococcal protein A is a marker of a set of VH genes (a subset of family VH3 in man) . We typed 115 monoclonal human Ig as alternative binders or nonbinders . The proportion of binders varied depending on the isotype, 35% in IgM but only 11-13% in IgA1 and IgG3 . It was 28% among lambda-chain-bearing but 16% among kappa-bearing monoclonal Ig . Independent estimates of the proportions bound were obtained by studying polyclonal Ig of 10 healthy adults . The proportions bound were close to those observed in the study of monoclonal Ig (the means were IgM 32%, IgA1 13%, IgA2 24%, IgG3 14%) . A higher proportion of infant than adult Ig was bound by protein A . Also, the proportion was less isotype-dependent in infants than in adults . At the age of 4 mo, 47% of IgM was bound (mean of 10 children), the values of other isotypes were: IgA1 35%, IgA2 39%, and IgG3 38% . At the age of 14 mo the proportion of alternative binders had decreased but was still far from adult values . We propose that ontogenically early ("virgin") B cells, besides being rich in IgM and lambda-chain producers, are rich in producers of alternative binders . A subsequent selection reduces the proportion of these B cells so that in ontogenically most developed B cell populations, e.g., those producing IgA1 kappa, such cells make up only about 10% of the total.

Semin Hematol, 1993 Oct, 30(4 Suppl 4), 16 - 24; discussion 25
New advances in vaccine delivery systems; Eldridge JH et al.; Successful application of the next generation of vaccines will require that protection be induced with a minimal number of administrations, and that a practical approach to inducing immunity at mucosal surfaces be developed . For these reasons, vaccine-containing microspheres were formulated from the biodegradable and biocompatible copolymer poly(DL-lactide-co-glycolide) {DL-PLG} . Subcutaneous immunization of mice with 1- to 10-microns microspheres containing a toxoid vaccine of staphylococcal enterotoxin B (SEB) induced a 500-fold potentiation of the circulating antitoxin response . Strong adjuvant activity was dependent on the microspheres being no more than 10 microns in diameter and required that the antigen was within the particles . The rate of DL-PLG biodegradation is a function of the ratio of lactide to glycolide, and the co-injection of SEB toxoid microspheres formulated with two different DL-PLG ratios stimulated both a primary and an anamnestic secondary antitoxin response . When it was administered by the oral or intratracheal (IT) route, microencapsulated SEB toxoid was found to be effective in the induction of concurrent circulating and disseminated mucosal antibody responses . Female rhesus macaques immunized with a microencapsulated simian immunodeficiency virus (SIV) vaccine produced high levels of circulating anti-SIV antibodies, and following oral or IT boosting, specific antibodies were found in vaginal wash fluids . Vaginal challenge with viable homologous SIV resulted in the infection of three out of four nonimmunized but only one out of seven microsphere-immunized macaques . Thus, DL-PLG microspheres are a promising approach to the delivery of vaccines, combining adjuvant activity with controlled release and effective presentation to mucosally associated lymphoid tissues (MALT).

Curr Eye Res, 1993 Oct, 12(10), 907 - 12
A natural history study of experimental Staphylococcus epidermidis endophthalmitis; Maxwell DP Jr et al.; The purpose of this study was to find a "threshold" quantity of organisms (i.e . inoculum) to produce clinical endophthalmitis and determine the natural course of intravitreal bacterial counts following inoculation in a rabbit model of Staphylococcus epidermidis endophthalmitis . S . epidermidis endophthalmitis was induced experimentally in 18 New Zealand white rabbits . Eyes were injected with 2.0 x 10(3) (Group I: n = 3), 2.0 x 10(4) (Group II: n = 3), 3.0 x 10(5) (Group III: n = 3), 3.0 x 10(6) (Group IV: n = 3), 3.0 x 10(7) (Group V: n = 3), or 3.0 x 10(8) (Group VI: n = 3) organisms . Serial quantitative bacterial cultures (colony counts) were performed on the vitreous every eight hours for 9 days . All eyes in Groups I and II became culture negative by 24-64 hours post-inoculation (PI) . All eyes in Groups III-VI remained culture positive {approximately 600-4000 colony forming units (CFU) per cm3} at 48 to 72 hours PI and were stable for the remainder of the nine day study period . Previous work suggests that the host's inflammatory response is more important than had been recognized . Previous rabbit models of infectious endophthalmitis are known to become culture negative ("autosterilized") despite continued intraocular inflammation . This rabbit model demonstrates a "threshold" of infection where the host's immune response is overwhelmed and "autosterilization" does not occur . When inoculated with 3.0 x 10(5) or greater S . epidermidis organisms of this strain, continued active bacterial replication can now be studied in the rabbit.

FEMS Immunol Med Microbiol, 1993 Oct, 7(3), 281 - 7
Peptidoglycan and teichoic acid from Staphylococcus epidermidis stimulate human monocytes to release tumour necrosis factor-alpha, interleukin-1 beta and interleukin-6; Mattsson E et al.; Cytokines play a major role in the pathophysiology of septic shock . In this study, human peripheral blood monocytes were stimulated with peptidoglycan and teichoic acid, purified from a strain of Staphylococcus epidermidis . Polymyxin B (PM-B) was added to avoid the effects of possible contamination with endotoxin . Tumour necrosis factor-alpha (TNF), interleukin-1 beta (IL-1), and interleukin-6 (IL-6) in the supernates were measured by enzyme-linked immunosorbent assays . Peptidoglycan and teichoic acid induced TNF, IL-1, and IL-6 in a concentration-dependent manner . Teichoic acid was a weaker inducer than peptidoglycan, especially for IL-1 . Lipopolysaccharide from an E . coli strain was used as a control, being 100-1000 times more potent than peptidoglycan and teichoic acid.

J Trop Pediatr, 1993 Oct, 39(5), 288 - 92
ARI control programme: results in hospitalized children; Mishra S et al.; One hundred cases of pneumonia with chest indrawing were treated according to the treatment protocol of the ARI control programme . The majority of children were > 2 months old (85 per cent) with male predominance (61 per cent) . All cases with severe pneumonia survived . A mortality rate of 7.7 per cent was seen in cases of very severe pneumonia . Three children in the severe pneumonia group deteriorated on benzyl penicillin to very severe pneumonia but subsequently improved on chloramphenicol . Six patients were treated as cases of Staphylococcal pneumonia and one of them died . Thirteen children (21.3 per cent) in the severe pneumonia group required oxygen for breathing rates > 70 per minute . Seventy-four per cent in the very severe pneumonia group required administration of IV fluids . Blood counts did not prove to be of help in differentiating the children at risk of dying . There was no significant difference in roentgenographic findings in the two groups . Congestive cardiac failure was the most common complication, seen in 33.3 per cent of cases of the very severe pneumonia group . The duration of stay was significantly less in cases of severe pneumonia (4.21 +/- 1.59 days) as compared to very severe pneumonia (9.35 +/- 2.39 days) . The data from this study suggest that the treatment protocol for the ARI control programme for hospitalized children is reasonably effective and can be implemented in small hospitals.

Cesk Pediatr, 1993 Oct, 48(10), 611 - 3
{Pulmonary hemorrhage in a neonate}; Zitek M et al.; The authors describe a case of pulmonary haemorrhage in a neonate associated with adnatal pneumonia and infection with Staphylococcus epidermidis . The authors discuss the problem of this serious complication of the neonatal period as well as the limited diagnostic and therapeutic possibilities.

Clin Infect Dis, 1993 Oct, 17(4), 679 - 85
Infections of implantable cardioverter defibrillators: approach to management; Spratt KA et al.; Implantable cardioverter defibrillators are being used with increasing frequency for the treatment of life-threatening ventricular arrhythmias . Nevertheless, no guidelines exist for the management of infections of these devices . We report our experience with infections of these devices and review the English-language literature . In all cases, patients presented with local signs of generator infection; systemic signs of infection and bacteremia were often absent . Most infections are due to staphylococcus . Risk factors for the development of infection include placement of the device via median sternotomy during another cardiac surgical procedure, reoperation, and intercurrent infection at another site . Infections are most reliably treated with full explantation of the device and antibiotics . In rare cases, patients may respond to a combination of intravenous antibiotics and removal and replacement of only the generator.

APMIS, 1993 Oct, 101(10), 802 - 4
Staphylococcus lugdunensis: an important cause of endocarditis . A case report; Schonheyder HC et al.; Staphylococcus lugdunensis endocarditis was diagnosed in a 55-year-old woman maintained on chronic haemodialysis . S . lugdunensis was isolated from blood and a Gore-Tex graft fistula at admission, and vegetations with Gram-positive cocci were found on the mitral cusps at autopsy.

New Microbiol, 1993 Oct, 16(4), 367 - 71
Natural infection of dogs by influenza C virus: a serological survey in Spain; Manuguerra JC et al.; Two seroepidemiological surveys carried out so far, one in Japan, the other in France, gave a strong indication that dogs may be naturally infected by influenza C virus, considered to be exclusively human until recently . In this work, 101 serum samples were collected during winter 1989/1990 from dogs in Castilla y Leon, Spain . Sera were tested for the presence of antibodies to influenza C virus by Hemagglutination Inhibition (HI) test . Using antibody absorption by staphylococcal protein A, we demonstrated the specificity of the results . Significant HI activity was found in 56.3% of the 101 tested sera and titres ranged from 25 to 200.

Clin Nephrol, 1993 Oct, 40(4), 205 - 7
Diagnosis and treatment of a solitary infected hepatic cyst in two patients with adult polycystic kidney disease; Gladziwa U et al.; We report on two women (one 52-year-old who underwent kidney transplantation 15 months ago and the other, 71-year-old, undergoing hemodialysis) both with adult polycystic kidney disease who had to be hospitalized because of recurrent fever attacks up to 40 degrees C without any remarkable abdominal symptoms . Staphylococcus hominis and E . coli were recovered respectively from blood cultures of both patients . Evidence for the presence of a solitary infected cyst in the liver could only be obtained by computed tomography (CT) with i.v . administration of a contrast medium . In both cases the infected liver cyst was non-operatively drained with a CT-guided percutaneous catheter and therefore the necessity of laparotomy was avoided.

J Clin Microbiol, 1993 Oct, 31(10), 2654 - 60
Improved purification and biologic activities of staphylococcal toxic shock syndrome toxin 1; Kum WW et al.; An improved method for producing highly purified toxic shock syndrome toxin 1 (TSST-1) by preparative isoelectric focusing in a Bio-Rad Rotofor cell and then chromatofocusing is described . Purification to homogeneity was confirmed by silver staining after sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE; 50 micrograms of protein was loaded), by immunoblotting with polyclonal rabbit antiserum raised against the crude culture supernatant used for purification, and by autoradiography after iodination and SDS-PAGE . Biologic activity was demonstrated by mitogenicity and cytokine induction (tumor necrosis factor alpha {TNF-alpha}, interleukin 1-beta {IL-1 beta}, and IL-6) of human peripheral blood mononuclear cells (PBMCs) and by lethality in New Zealand White rabbits following subcutaneous infusion . In contrast to commercial TSST-1 preparations, our TSST-1 preparation required the presence of both monocytes and T cells for the induction of TNF-alpha and IL-1 beta from human PBMCs . A 46-kDa contaminating protein in the commercial TSST-1 preparation, identified as staphylococcal lipase, was likely responsible for the induction of TNF-alpha and IL-1 beta from human monocytes in the absence of T cells, a biologic activity falsely attributed to purified TSST-1 . Our improved purification procedure for TSST-1 provides a high yield and is both more rapid and less labor intensive than previously reported methods . Furthermore, our studies clearly demonstrate the need for stringent methods of purity assessment of TSST-1 preparations before ascribing to them their potent biologic activities.

Mol Gen Genet, 1993 Oct, 241(1-2), 33 - 41
Cloning and characterization of the scrA gene encoding the sucrose-specific Enzyme II of the phosphotransferase system from Staphylococcus xylosus; Wagner E et al.; By insertional mutagenesis with the staphylococcal transposon Tn551, mutants of Staphylococcus xylosus were isolated that were unable to utilize sucrose . One of these was found to be deficient in sucrose uptake . The genomic region containing this sucrose uptake gene of Staphylococcus xylosus (scrA) was cloned in Staphylococcus carnosus . The scrA gene was further localized to a 4.4 kb DNA fragment by complementation of the sucrose transport-deficient S . xylosus mutant . The DNA sequence analysis of the scrA region revealed three open reading frames, one of which encodes a protein of 480 amino acids (51.335 kDa) with significant similarity to sucrose-specific Enzymes II of phosphoenolpyruvate-dependent carbohydrate phosphotransferase systems (PTS) . A protein with an apparent molecular weight of 50 kDa was obtained in Escherichia coli by expression of scrA with the bacteriophage T7 RNA polymerase promoter system . Transcriptional start sites of the scrA gene were localized by primer extension analysis to positions 46 and 49 nucleotides upstream of the scrA start codon . No additional sucrose utilization genes are encoded close to scrA on the S . xylosus chromosome.

Br J Dermatol, 1993 Oct, 129(4), 399 - 402
Follicular concentrations of azelaic acid after a single topical application; Bojar RA et al.; Follicular concentrations of azelaic acid (AzA) were determined in vivo using a rapid, non-invasive method, after a single topical application of 20% (w/w) AzA cream, in order to establish whether the in vitro antimicrobial effects observed in previous studies are relevant in vivo . Preweighed amounts of 20% (w/w) AzA cream were applied over demarcated areas on the forehead and back of nine young adults, and samples were taken over a period of 5 h . AzA was removed from the skin surface by washing with acetone, and follicular casts were collected using cyanacrylate gel . The samples were centrifuged to remove particulate matter, and the supernatants derivatized for analysis by HPLC . Although the results showed wide-ranging variability, the follicular concentration increased as the amount present on the surface declined . The maximum follicular concentrations of AzA attained ranged from 7.5 to 52.5 ng (micrograms of follicular casts)-1 and 0.5 to 23.4 ng (micrograms of follicular casts)-1 in samples taken from the back and forehead, respectively . Assuming an average density of follicular material of 0.9 g ml-1, the mean maximum follicular concentration attained on the back was between 36 and 251 mmol/l, and on the forehead was between 2 and 112 mmol/l, and indicates that the concentration of AzA attained in follicular casts after a single topical application is comparable with the concentration required to inhibit the growth of Propionibacterium acnes and Staphylococcus epidermidis, in vitro.

Eur J Immunol, 1993 Oct, 23(10), 2661 - 6
Clonal anergy to staphylococcal enterotoxin B in vivo: selective effects on T cell subsets and lymphokines; Baschieri S et al.; Injection of bacterial superantigens such as staphylococcal enterotoxin B (SEB) in adult mice results in initial proliferation of SEB-responsive V beta 8+ T cells followed by induction of a state of non-responsiveness frequently referred to as clonal anergy . We show here that SEB-induced anergy involves selective changes in lymphokine production and that it affects CD4+ V beta 8+ and CD8+ V beta 8+ T cells in different fashions . Whereas both CD4+ V beta 8+ and CD8+ V beta 8+ cells from anergic mice exhibit strongly reduced proliferative capacity and interleukin(IL)-2 production upon restimulation with SEB either in vivo or in vitro the CD8+ subset from SEB-injected mice produces other lymphokines (such as interferon(IFN)-gamma) at normal or slightly increased levels in response to SEB . Changes in the levels of production of IL-2 and IFN-gamma protein correlated well with mRNA accumulation both in vivo and in vitro . Collectively these data suggest that superantigen-induced anergy involves selective changes in signal transduction and/or gene regulation in T lymphocytes.

Cardiovasc Surg, 1993 Oct, 1(5), 489 - 93
Vascular graft infections: a personal experience; Bunt TJ; Fifty-five vascular graft infections were personally managed by the author over an 8-year period . For 22 patients with aortic graft infection, Staphylococcus epidermidis was the most common pathogen (18 of 22 patients), presenting as limb thrombosis in nine and pseudoaneurysm in five . All patients underwent staged extra-anatomic reconstruction and graft resection 4-5 days later . For 33 patients with peripheral infection, S . aureus was the most common pathogen (29 of 33 patients), presenting as clinical graft sepsis usually within months of initial operation . Local therapy was successful in seven of nine patients, whereas graft resection with autologous reconstruction achieved limb salvage in all 11 patients involved . Overall, the mortality rate was 9.1% for 22 aortic and zero for 33 peripheral infections; amputation rates were 14 and 12%, respectively.

Rev Rhum Ed Fr, 1993 Oct, 60(9), 610 - 3
{Infectious osteoarthritis of the pubis in sportmen . Apropos of 2 cases}; Sibilia J et al.; In athletes, osteoarthritis of the symphysis pubis is an uncommon condition that should be promptly differentiated from pubic pain due to microtrauma . The symphysis pubis is infected via the bloodstream, usually by a staphylococcus . Pubic pain with fever and severe disability suggests the diagnosis . Increased uptake of bone-seeking radionuclides is an early finding . Microbiological and histological studies of specimens obtained under radiological guidance confirm the diagnosis . Two new cases of pubic osteoarthritis in young athletes are reported . In one case the causative organism was a Peptostreptococcus, a gram-positive commensal organism normally found on the skin and mucous membranes.

J Med Assoc Thai, 1993 Oct, 76(10), 559 - 63
Intravenous followed by oral antimicrobial therapy for staphylococcal endocarditis; Chayakul P et al.; Nine men with ten episodes of staphylococcal endocarditis with valvular vegetation (except one) were treated with intravenous cloxacillin for an average of 10 days and followed by oral cloxacillin or dicloxacillin, both with probenecid, for a total duration of 4 wks . Monitoring of serum bactericidal titers (SBT) showed similar values between the two routes of therapy . All patients were bacteriologically and clinically cured . However, there were 3 recurrences, 2 were drug abusers . One nonabuser had the same staphylococcal species 8 months later . All survived the second episode . This preliminary study supports the contention that intravenous followed by oral therapy for staphylococcal endocarditis may be a viable and a more economical form of therapy.

Community Dent Oral Epidemiol, 1993 Oct, 21(5), 313 - 6
Association of psychotropic drugs, prevalence of denture-related stomatitis and oral candidosis; Lucas VS; The aims of this study were 1) to determine the association between the prevalence of denture-related stomatitis and oral candidosis in patients undergoing long-term treatment with psychotropic drugs and 2) to identify the relationships between an increased prevalence of oral candidosis, denture cleanliness, dietary habits and cigarette smoking in these patients . Clinical and laboratory investigation of psychiatric patients under treatment with psychotropic drugs and who were wearing complete maxillary dentures, compared with control (non-psychiatric) patients revealed that 1) the isolation frequency of candida was 64.7% compared with 33.3% in the controls; 2) palatal inflammation was present in 74.5% compared with 55% of the controls; 3) oral staphylococcus carriage was present in 56.9% compared with 17.6% of the controls; 4) cigarette smoking, sugar consumption and a poor standard of denture hygiene were more common in the psychiatric patients than in the controls.

Immunology, 1993 Oct, 80(2), 242 - 7
B7/CD28 but not LFA-3/CD2 interactions can provide 'third-party' co-stimulation for human T-cell activation; Sansom DM et al.; The requirement for co-stimulation in T-cell activation has become firmly established, whilst the precise identity of the molecules involved remains uncertain . Some of the major co-stimulatory molecules include ICAM-1, LFA-3 and B7 . We have investigated the abilities of both LFA-3 and B7 to co-stimulate T-cell proliferation under a number of conditions using transfected Chinese hamster ovary cells . Using anti-CD3 antibodies we observed that B7 but not LFA-3 transfectants were capable of co-stimulating proliferation in purified peripheral blood T cells . In addition, both LFA-3 and B7 could induce proliferation in response to phytohaemagglutinin (PHA) and we obtained additive effects using both B7 and LFA-3 together . Using the superantigen staphylococcal enterotoxin B (SEB), we observed that presentation to purified T cells required the presence of class II-positive transfectants and that sensitivity to antigen was increased approximately 100-fold by the co-transfection of either B7 or LFA-3 . However, when co-stimulatory molecules were provided by cells separate from those engaging the T-cell receptor (TcR), only B7 was capable of enhancing proliferation . Kinetic studies which investigated the time dependence for co-stimulation revealed that T cells responding to anti-CD3 antibodies required the B7 co-stimulation within the first few hours, for proliferation to be effective . Our data differentiate between the co-stimulatory abilities of B7 and LFA-3 and support the concept of a pivotal role for B7 in T-cell proliferation.

Immunology, 1993 Oct, 80(2), 236 - 41
Co-stimulation with B7 and targeted superantigen is required for MHC class II-independent T-cell proliferation but not cytotoxicity; Lando PA et al.; The superantigen Staphylococcal enterotoxin A (SEA) conjugated to tumour-specific monoclonal antibodies (mAb) directs T cells to lyse tumour cells in the absence of major histocompatibility complex (MHC) class II . In contrast, the conjugate bound to MHC class II-negative tumour cells did not activate resting T cells to proliferate . The SEA-C215 mAb conjugate, when presented on the CA215 antigen-expressing Colo205 cells, required either signalling with CD28 mAb or CHO cells expressing the natural CD28 ligand, B7, to activate the T cells . The CD28/B7 co-stimulatory effect was further enhanced when the B7 and the tumour antigen were present on the same cell, decreasing the superantigen amount required for activation with a factor of 10(4) . No influence of B7 was seen when the single CA215 or double CA215/B7 transfectants were used as targets for superantigen conjugate-dependent cytotoxicity . This suggests that the low affinity T-cell receptor (TcR) interaction of superantigen in the absence of MHC class II antigens is sufficient for induction of cytotoxicity but requires additional CD28/B7 signalling to result in proliferation of resting T cells.

Biochemistry, 1993 Sep 28, 32(38), 10131 - 9
Patterns of nonadditivity between pairs of stability mutations in staphylococcal nuclease; Green SM et al.; To identify interactions between amino acid positions in staphylococcal nuclease that affect its stability, a collection of 71 double-mutant forms was constructed from 22 previously characterized single mutants . These single mutations were assigned to three different classes on the basis of their m value {m = d(delta G)/d{GuHCl}}, a parameter that has been correlated with energetically significant changes in the structure of the denatured state {Green et al . (1992) Biochemistry 31,5717-5728} . Several mutant pairs from five of the six possible double-mutant classes were analyzed by guanidine hydrochloride denaturation to determine the extent to which changes in stability (delta delta GH2O) and changes in the m value (delta mGuHCl) reflect the sum of the effects of the individual mutants . The differences between the values for delta delta GH2O and delta mGuHCl estimated on the assumption of additivity and those obtained by experiment, i.e., delta delta delta G and delta delta m, were calculated for each double-mutant protein . Surprisingly, a large majority of double mutants from four of the five classes exhibited positive values of delta delta delta G and delta delta m; i.e., they were more stable and displayed a higher sensitivity to GuHCl than predicted on the basis of additivity.(ABSTRACT TRUNCATED AT 250 WORDS)

Science, 1993 Sep 17, 261(5128), 1578 - 81
Probing the mechanism of staphylococcal nuclease with unnatural amino acids: kinetic and structural studies; Judice JK et al.; Staphylococcal nuclease is an enzyme with enormous catalytic power, accelerating phosphodiester bond hydrolysis by a factor of 10(16) over the spontaneous rate . The mechanistic basis for this rate acceleration was investigated by substitution of the active site residues Glu43, Arg35, and Arg87 with unnatural amino acid analogs . Two Glu43 mutants, one containing the nitro analog of glutamate and the other containing homoglutamate, retained high catalytic activity at pH 9.9, but were less active than the wild-type enzyme at lower pH values . The x-ray crystal structure of the homoglutamate mutant revealed that the carboxylate side chain of this residue occupies a position and orientation similar to that of Glu43 in the wild-type enzyme . The increase in steric bulk is accommodated by a backbone shift and altered torsion angles . The nitro and the homoglutamate mutants display similar pH versus rate profiles, which differ from that of the wild-type enzyme . Taken together, these studies suggest that Glu43 may not act as a general base, as previously thought, but may play a more complex structural role during catalysis.

Proc Natl Acad Sci U S A, 1993 Sep 15, 90(18), 8543 - 6
Staphylococcal enterotoxins can reactivate experimental allergic encephalomyelitis; Schiffenbauer J et al.; Staphylococcal enterotoxins (SEs) are one member of a unique group of molecules known as superantigens . They are potent T-cell activators and stimulate a large number of T cells bearing specific T-cell-receptor beta-chain variable regions . It has been proposed that superantigens may trigger autoimmune disorders by stimulation of autoreactive T cells with restricted beta-chain variable-chain usage . We investigated the effects of SEs B and A (SEB and SEA) on the reactivation of experimental allergic encephalomyelitis, an animal model for multiple sclerosis . We report that SEB can reinduce encephalitis multiple times in PL/J mice that had previously recovered from an acute episode . SEB was also able to induce encephalitis in mice previously immunized with myelin basic protein but did not show clinical signs of disease . In addition, it was observed that T cells from PL/J mice that had been previously activated by myelin basic protein in complete Freund's adjuvant or in complete Freund's adjuvant alone were resistant to the induction of anergy by SEB . To determine whether reactivation of experimental allergic encephalomyelitis was specific for SEB, another superantigen, SEA, was employed . It was found that SEA was also able to reinduce experimental allergic encephalomyelitis in mice previously recovered from an acute episode and those that had been previously immunized with myelin basic protein but did not show clinical signs of disease . These results indicate that SEs are capable of reactivating autoreactive T cells and inducing autoimmune disease.

J Biol Chem, 1993 Sep 15, 268(26), 19274 - 83
Structural and functional domains of apolipoprotein A-I within high density lipoproteins; Dalton MB et al.; We prepared discoidal and spherical model high density lipoprotein (HDL) with apolipoprotein A-I and 1-palmitoyl-2-oleoyl phosphatidylcholine at various lipid:protein ratios and compared their reactivity with exo- and endopeptidases to that of human HDL2 and HDL3 . Limited proteolysis with trypsin, Staphylococcus V8 protease, and elastase yielded a major stable peptide of 11,000-11,500 daltons under conditions which completely degraded lipid-free A-I . By Western blotting this protease-resistant fragment was shown to consist of the amino-terminal 90-100 residues of the A-I protein; the residues on the carboxyl side of this peptide are therefore protease-sensitive and appear to correlate with the putative "hinge" region, which is especially reactive with antibodies . The amino terminus was very resistant to digestion with a variety of aminopeptidases, whereas carboxypeptidases could remove up to 70 residues from the lipid-free A-I protein or 12-24 residues from A-I in various HDL . When these truncated forms of A-I, in combination with lipid, were used to examine binding interactions with rat hepatic plasma membranes, it was found that removal of up to 20-24 residues from the carboxyl terminus had no significant effect on binding, whereas removal of 70 residues completely eliminated specific binding to the membranes . Taken together, our data indicate that there is a protease-resistant domain constituted by the first 90 residues of A-I, which, in HDL, contain little of the class of amphipathic helix characteristic of the rest of the molecule and most likely form a structure dominated by protein-protein interactions . At the carboxyl end of the protein, there is a functional domain constituted by residues 149-219 that possesses the capacity to bind to proteins on hepatic membranes.

Virology, 1993 Sep, 196(1), 146 - 62
Herpes simplex virus 1 alkaline nuclease is required for efficient egress of capsids from the nucleus; Shao L et al.; We previously described the isolation of AN-1, a null mutant of the HSV-1 alkaline nuclease gene, which is able to synthesize near wild-type levels of viral DNA and late viral proteins under nonpermissive growth conditions; these results lead us to conclude that the alkaline nuclease is not essential for viral DNA synthesis (Weller, S . K., Seghatoleslami, R . M., Shao, L., Rowse, D., and Carmichael, E . P., 1990, J . Gen . Virol . 71, 2941-2952) . AN-1 was found to be deficient in the production of infectious virions suggesting that the nuclease may play a role in processing or packaging of viral DNA into infectious virions . In this report we demonstrate that the defect is distinct from that observed in other late HSV-1 mutants which make but fail to process viral DNA under nonpermissive growth conditions . Following restriction enzyme digestion, specific terminal fragments are observed in DNA from AN-1-infected Vero cells, indicating that specific cleavage has occurred; moreover, the efficiency of cleavage is at near wild-type levels . Also in contrast to cells infected with previously described late mutants, DNase I or staphylococcal nuclease resistant DNA is observed in these cells further indicating that encapsidation has occurred . Three lines of evidence suggest, however, that maturation of DNA-containing AN-1 capsids is defective in some ways . First, in contrast to wild-type, very small amounts of protected DNA is detected in cytoplasmic extracts from AN-1-infected cells . Second, very few if any mature, DNA-containing C capsids are observed in the cytoplasm when analyzed by electron microscopy or sucrose gradient sedimentation . Finally, analysis of nuclei by sucrose gradient sedimentation indicates an elevated ratio of A to B capsids . These data indicate that AN-1 may be defective for the production of capsids competent to mature into the cytoplasm . Possible models for the nature of the defect in AN-1 will be discussed.

Am J Kidney Dis, 1993 Sep, 22(3), 430 - 5
Interleukin-6 and interleukin-8 in dialysate and serum from patients on continuous ambulatory peritoneal dialysis; Brauner A et al.; We investigated interleukin-6 (IL-6) and interleukin-8 (IL-8) in peritoneal dialysate and serum from 17 patients on continuous ambulatory peritoneal dialysis (CAPD) with a total of 24 episodes of peritonitis and from 14 non-infected CAPD controls . Bacterial growth was found in 20 (83%) of the dialysate samples . Staphylococcus epidermidis caused 40% of the culture-verified peritonitis . Samples from dialysate were obtained during the first month of dialysis and during peritonitis from the first three dialysate bags on day 1 (the day of admittance) and from night bags on days 3 and 10 . Serum samples were drawn on days 1 and 10 . Interleukin-6 was increased in all dialysate samples on day 1 . The peak median concentration was 23,500 pg/mL (range 1,710 to 340,000 pg/mL) in the first dialysate . Interleukin-8 was also elevated from all patients in the first dialysate, with a peak median value of 2,000 pg/mL (range, 110 to 185,000 pg/mL) . Interleukin-6 and IL-8 concentrations from peritoneal fluid on days 1, 3, and 10 were significantly higher than concentrations from CAPD controls (IL-6 median value, 90 pg/mL, P < 0.001; IL-8 median value, nondetectable, P < 0.001) . In serum, IL-6 and IL-8 were detected in 83% and 65% of the episodes, respectively . A correlation (P = 0.007) was seen between IL-6 and IL-8 in the first dialysate sample, but not in the subsequent dialysate samples . The highest acute phase reactant (CRP) level obtained during the peritonitis episode correlated to IL-6 in serum (P < 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Eur J Immunol, 1993 Sep, 23(9), 2306 - 10
Role of transforming growth factor-beta in the preferential induction of T helper cells of type 1 by staphylococcal enterotoxin B; Nagelkerken L et al.; Stimulation of murine CD4+ T cells with staphylococcal enterotoxin B (SEB) results in the preferential development of T helper (Th) 1 cells {i.e . high interferon (IFN)-gamma and low interleukin (IL)-4, IL-5 and IL-10}; whereas in response to plate-bound anti-CD3 or anti-T cell receptor-alpha beta, Th1 as well as Th2 cells develop . In the present study, we examined the mechanism which is responsible for the selective Th1 development in the SEB system . The addition of IL-4 resulted in a strong development of Th2 cells showing that SEB stimulation can result in Th2 differentiation . Co-stimulation with anti-CD28 was insufficient in this regard . Lack of Th2 development in the SEB system was in part due to the inhibitory effect of endogenously produced transforming growth factor-beta (TGF-beta), because anti-TGF-beta allowed the development of Th2 cells . Similarly, TGF-beta inhibited Th2 development and stimulated Th1 development in the anti-CD3 system . This shift was only partially prevented by also including IL-4 in the cultures . The effects of TGF-beta could only partially be explained by stimulation of IFN-gamma or inhibition of IL-4 as intermediatory cytokines: (1) TGF-beta stimulated Th1 development even in the presence of anti-IL-4 and anti-IFN-gamma, and (2) a strong inhibitory effect of anti-TGF-beta on Th1 development was still observed when anti-IL-4 and IFN-gamma were simultaneously added to the cultures . It is concluded that SEB favors Th1 development by stimulation of TGF-beta production . Inhibition of Th2 development by TGF-beta is due, in part, to inhibition of IL-4 and stimulation of IFN-gamma, and, in part, to a direct effect of TGF-beta on the responding T cells.

Eur J Immunol, 1993 Sep, 23(9), 2129 - 35
Activator protein-1 (AP-1) is stimulated by microbial superantigens in human monocytic cells; Trede NS et al.; Microbial superantigens bind to major histocompatibility complex (MHC) class II molecules and activate gene transcription in monocytes . In search of transcription factors that potentially mediate the effects of superantigens at the nuclear level, we examined the capacity of staphylococcal superantigens to stimulate the activity of the transcriptional promoter factor activator protein-1 (AP-1) . Electrophoretic mobility shift assays showed an increase in nuclear proteins that bound to the consensus AP-1 motif within 5 min following the stimulation of the monocytic cell line THP-1 with toxic shock syndrome toxin-1 (TSST-1) or staphylococcal endotoxin A . We show that mRNA levels for the subunits that compose AP-1, the protooncogenes c-fos and c-jun, are upregulated by stimulation of THP-1 cells with TSST-1 . The activated AP-1 complexes were functional, as evidenced by the capacity of TSST-1 to stimulate the expression of an AP-1-driven reporter gene construct transfected into THP-1 cells . These results establish that the engagement of MHC class II molecules by superantigens increases the activity of functional AP-1 complexes and that this may proceed in part by transcriptional activation of c-fos and c-jun protooncogenes.

J Med Microbiol, 1993 Sep, 39(3), 204 - 10
An electronmicroscope study of glycopeptide antibiotic-resistant strains of Staphylococcus epidermidis; Sanyal D et al.; Ultra-thin section transmission electronmicroscopy revealed that two of three glycopeptide-resistant strains of Staphylococcus epidermidis had abnormally thick cell walls, a finding consistent with the view that the reduction in susceptibility may result from the overproduction of glycopeptide binding sites within the cell-wall peptidoglycan . The third resistant strain had a slightly thickened cell wall with an irregular, roughened outline; this strain also underwent autolysis on prolonged incubation on blood agar and the resistance may be associated with abnormal cell-wall synthesis . Sub-MIC concentrations of vancomycin and teicoplanin caused surface damage to a proportion of cocci able to grow in the presence of antibiotic . Exposure to teicoplanin was additionally associated with the formation of filamentous forms and variable amounts of extracellular material . Transmission electronmicroscopy showed that both antibiotics exerted effects within the bacterial cytoplasm of the resistant strains that were not seen in an NCTC control strain: intracellular lamellae and structures resembling mesosomes were observed in the former . These effects were more noticeable in cocci exposed to vancomycin . Bacteria exposed to teicoplanin often showed abnormal septation and, in some preparations, a double-layered cell wall.

J Med Microbiol, 1993 Sep, 39(3), 196 - 203
Chemiluminescence of human polymorphonuclear leucocytes after stimulation with whole cells and cell-wall components of Staphylococcus epidermidis; Martinez-Martinez L et al.; The purpose of this study was to define cell-wall components of Staphylococcus epidermidis responsible for activation of human polymorphonuclear leucocytes (PMNL) . Metabolic activation of PMNL was determined by chemiluminescence (CL) . Purified peptidoglycan (PG) induced a concentration-dependent metabolic burst in PMNL . The minimal concentration needed for CL induction was 1 microgram/ml . Comparison between different S . epidermidis strains showed variation in the capacity to induce CL in PMNL . Purified PG induced a higher CL response in PMNL than its intact parent strain; this effect was found in all S . epidermidis strains . Lipoteichoic acid (LTA), PG stem peptide and muramyldipeptide (MDP) did not induce CL; teichoic acid induced a CL response only at very high concentrations . No differences in CL inducing capacity were found between PG, crude cell walls, and purified cell walls of S . epidermidis . Sonication of PG strongly diminished CL-inducing capacity . PG treatment with mutanolysin immediately resulted in decreased CL-inducing capacity . Treatment of PG with S . aureus lytic enzyme (SALE) 10 micrograms/ml for up to 15 min enhanced the CL response to PMNL; a similar increase in CL was induced by PG treated with SALE at 1 microgram/ml for up to 120 min . Beyond these times, a continuous decrease in PG-induced CL was observed . In conclusion, PG was found to be the major cell-wall component of S . epidermidis involved in CL induction . Moreover, a minimal fragment size or a specific tertiary structure of PG, or both, is required for metabolic activation of PMNL.

Arch Ophthalmol, 1993 Sep, 111(9), 1210 - 8
0.3% ciprofloxacin ophthalmic ointment in the treatment of bacterial keratitis . The Ciprofloxacin Ointment/Bacterial Keratitis Study Group; Wilhelmus KR et al.; OBJECTIVE: To determine the efficacy and safety of topical 0.3% ciprofloxacin hydrochloride ophthalmic ointment in the treatment of bacterial keratitis . DESIGN: Prospective case series with a nonrandomized comparison of culture-positive, evaluable cases (ciprofloxacin ointment group) with culture-positive, concurrent patients (nonenrolled group) treated with conventional therapy . SETTING: Multicenter clinical study . PATIENTS: After informed consent was obtained, 253 eligible patients underwent corneal scrapings and received topical ciprofloxacin ointment; 145 (57%) had positive cultures and completed the follow-up schedule . Forty (70%) of 57 apparently eligible patients had culture-positive bacterial keratitis but were not enrolled in the ciprofloxacin ointment study during the same period . INTERVENTION: Ciprofloxacin ophthalmic ointment instilled every 1 to 2 hours for 2 days, then every 4 hours for 12 days . MAIN OUTCOME MEASURES: Clinical evaluation of signs at 1, 3, 7, and 14 days of treatment and the overall condition classified as clinical success (cured or improved) or failure (unchanged or worse) during and after therapy . RESULTS: Clinical success with the initial treatment occurred in 135 patients (93%) in the ciprofloxacin ointment group and in 28 patients (70%) in the nonenrolled group . Of the 10 ciprofloxacin clinical failures, seven were staphylococcal; two, pneumococcal; and one, polybacterial . The 90% minimum inhibitory concentration of ciprofloxacin was 3 mg/L or less for corneal bacterial isolates . No serious adverse event attributable to ciprofloxacin ointment occurred, although 32 (13%) of 253 patients developed a transient white crystalline corneal precipitate shown with liquid chromatography in two cases to be ciprofloxacin . CONCLUSION: Ciprofloxacin ophthalmic ointment is an effective and safe topical antimicrobial agent for the treatment of bacterial keratitis caused by susceptible microorganisms.

J Immunol, 1993 Sep 1, 151(5), 2733 - 41
Transcriptional down-regulation of tumor necrosis factor-alpha gene expression by a synthetic peptide homologous to retroviral envelope protein; Haraguchi S et al.; We have previously shown that a synthetic peptide (CKS-17) homologous to retroviral envelope protein suppresses the accumulation of superantigen staphylococcal enterotoxin-induced TNF-alpha mRNA in human PBMC and in highly purified human monocytes . The present study was designed to examine the underlying mechanism(s) by which CKS-17 down-regulates the TNF-alpha mRNA expression using a human acute monocytic leukemia cell line THP-1 stimulated with the superantigen staphylococcal enterotoxin E . A cyclooxygenase inhibitor indomethacin does not reverse the inhibition of TNF-alpha mRNA expression by CKS-17, suggesting that prostaglandins are not responsible for the suppressive action of CKS-17 . The inhibitory effect of CKS-17 is, however, significantly blocked by a protein synthesis inhibitor cycloheximide, indicating that CKS-17 requires de novo protein synthesis to induce the suppressive activity . The mRNA stability assays using actinomycin D show that CKS-17 does not decrease the TNF-alpha mRNA stability . Nuclear run-on transcription assays further reveal that CKS-17 suppresses the TNF-alpha mRNA transcription rate . Taken together, these results suggest that the synthetic retroviral peptide CKS-17 down-regulates TNF-alpha mRNA expression through inhibition of transcriptional activation of the TNF-alpha gene, which requires de novo synthesis of a transcriptional repressor protein(s).

Infect Immun, 1993 Sep, 61(9), 4013 - 6
Staphylococcus-mediated T-cell activation and spontaneous natural killer cell activity in the absence of major histocompatibility complex class II molecules; Chapes SK et al.; We used major histocompatibility complex class II antigen-deficient transgenic mice to show that in vitro natural killer cell cytotoxicity and T-cell activation by staphylococcal exotoxins (superantigens) are not dependent upon the presence of major histocompatibility complex class II molecules . T cells can be activated by exotoxins in the presence of exogenously added interleukin 1 or 2 or in the presence of specific antibody without exogenously added cytokines.

Infect Immun, 1993 Sep, 61(9), 3976 - 80
Tumor necrosis factor alpha (TNF-alpha) production in mice immunized with Escherichia coli: correlation with mortality after lethal challenge and production of a native inhibitor of TNF-alpha activity; Raponi G et al.; The kinetics of tumor necrosis factor alpha (TNF-alpha) production, the correlation between cytokine levels and mortality rates after lethal challenge, and the production of a native inhibitor of TNF-alpha activity was investigated in mice immunized with formalin-killed Escherichia coli . Groups of mice were injected for 8 weeks with either untreated bacteria or bacteria treated with 0.5 MIC of aztreonam and subsequently challenged with 100 50% lethal doses of viable E . coli . Mice receiving saline only (controls) died within 24 h . The mortality of mice immunized with aztreonam-treated E . coli was significantly lower than that of mice immunized with untreated E . coli . There were no measurable levels of TNF-alpha in sera obtained from control mice during the entire period of immunization . TNF-alpha levels ranging from 90 to 306 U/ml were measured 90 min after each vaccination in sera obtained from mice immunized with untreated E . coli . Sera from mice immunized with antibiotic-treated E . coli showed lower TNF-alpha levels, ranging from 40 to 128 U/ml . TNF-alpha levels measured 90 min after lethal challenge correlated with the mortality rate observed in each group (r = 0.95) . The cytotoxic activity of recombinant murine TNF-alpha was inhibited by the sera from immunized mice but not by the sera from controls . The inhibition was drastically reduced by preincubation of the sera with staphylococcal protein A . In immunoblot experiments, class G immunoglobulins reacting with recombinant murine TNF-alpha were observed in the sera of immunized mice . These data confirm the correlation existing between TNF-alpha levels and mortality and suggest that native inhibitors may play a role in the regulation of the biological function of the cytokine.

J Invest Surg, 1993 Sep-Oct, 6(5), 461 - 7
Implanted right atrial catheters for continuous infusion of solutions into dogs; Dennis MB Jr et al.; Silastic catheters were fabricated and aseptically implanted through the skin into the jugular vein of 64 dogs with the intravascular tip located in the right atrium . Solutions were infused through the catheter at 2 to 2.5 mL/h by a portable pump worn by the dog . Following 9.2 Gy total body irradiation (TBI) and allogeneic bone marrow transplantation (BMT), succinyl acetone, an experimental chemotherapeutic agent, was infused into 34 dogs . Hematopoietic growth factors were infused into an additional 30 dogs, two of which had 9.2 Gy TBI and an autologous BMT, and four of which had 4.0 Gy TBI and no BMT . All dogs received continuous oral and parenteral antibiotics while the catheters were in place . All catheters functioned well until electively removed (n = 28) or until the dogs died or were euthanized (n = 36) at 12 to 68 days after implantation . Mean length of catheter function was 30.3 +/- 1.5 (SEM) days . No catheters were dislodged and there was no evidence of catheter-related blood loss or sepsis . Semiquantitative cultures of 5 catheters were negative, but Staphylococcus epidermidis was isolated from 3 of 7 catheters cultured in broth . Six dogs had thrombosis adjacent to the intravascular catheter tip . The catheters were well tolerated and facilitated successful long-term infusion of solutions into dogs.

Microb Pathog, 1993 Sep, 15(3), 217 - 25
Staphylococcus hyicus-skin reactions in piglets caused by crude extracellular products and by partially purified exfoliative toxin; Andresen LO et al.; Staphylococcus hyicus may cause a spontaneous generalized exudative epidermitis in piglets . The progression and regression of macroscopical and histopathological lesions in piglet skin after subcutaneous injection of sterile concentrated culture supernatant (CCS) from one virulent and one avirulent strain of S . hyicus was studied every 24 h until 144 h post-injection . CCS from the virulent strain caused local alterations of the epidermis comparable to those of spontaneous exudative epidermitis: exfoliation, crust formation, exocytosis, formation of vesicles, and pustules and acanthosis . CCS from the avirulent strain only caused a transient erythema of the skin and no histopathological alterations of the epidermis . Additionally, proteins in CCS from the virulent strain were fractionated by column chromatography . Skin reactions similar to those caused by CCS from the virulent strain were induced by one fraction of proteins that contained eight protein bands in SDS-PAGE analysis . Two of these protein bands, with molecular weights of approximately 27 kDa and 30 kDa, were unique to the virulent strain compared to the avirulent strain . The results of this study indicate that one of these two proteins or both is a heat-labile exfoliative toxin, and that the toxin is a significant factor in the pathogenesis of exudative epidermitis in piglets.

Indian J Med Res, 1993 Sep, 97, 206 - 8
Studies on antibacterial properties of gentian violet impregnated silastic; Bhatnagar V et al.; The antibacterial activity of gentian violet (GV) impregnated silastic discs was studied by measuring the zone of inhibition (ZOI), (in mm) produced by the discs planted on Staphylococcus epidermidis seeded agar plates . The effect of varying concentration of GV, the duration of antibacterial activity and effect of autoclaving were studied . The mean ZOI for 1 per cent GV was 19.28 +/- 0.89 mm and for 2 per cent GV it was 22.55 +/- 0.71 mm (P < 0.001) . There was no significant difference between GV concentrations of 2-5 per cent . Over a period of 1-5 wk, no significant difference was found in the antibacterial activity of GV for any of the concentrations . In each of the concentrations there was a significant reduction in the ZOI after multiple autoclavings . The study thus indicates that it is possible to impart antibacterial properties to silastic implants so that their colonization with Staph . epidermidis can be prevented and this finding has obvious clinical implications.

AIDS Res Hum Retroviruses, 1993 Sep, 9(9), 897 - 905
The effect of age on the course of experimental feline immunodeficiency virus infection in cats; George JW et al.; Neonatal, young adult, and aged specific pathogen-free cats were experimentally infected with cat-passaged Petaluma strain of feline immunodeficiency virus . The primary stage of illness occurred 6-8 weeks following infection in cats of all ages, but it differed in severity and clinical signs . Generalized lymphadenopathy persisted for the entire 42-week study period in neonatally infected cats, was transient in young adults, but inapparent in aged cats . Only two aged cats became chronically and severely ill during the study . One aged cat died with severe necrotizing transmural enteritis, while a second developed chronic generalized staphylococcal pyoderma that was partially controlled with antibiotics . Neutropenia appeared 6-8 weeks following infection in cats of all ages, but was more severe in newborn and aged cats than in young adults . A persistent decrease in CD4+/CD8+ T lymphocyte ratios, due to both increased CD8+ and decreased CD4+ T lymphocytes, occurred in the neonatal and aged cats . Decreased CD4+/CD8+ T lymphocyte ratios in the young adult cats was due solely to decreased CD4+ T lymphocytes . Antibody response to FIV virus, as measured by ELISA to recombinant FIV p24 antigen, was lower in aged cats than the other age groups during the first 6 weeks after infection . Antibody levels were not significantly different among the three age groups thereafter . Although there are some differences between FIV infection of cats and HIV infection of human beings, age at infection influences the severity of disease in both species.

Pathol Biol (Paris), 1993 Sep, 41(7), 583 - 8
{Absence of distinctive characteristics between Staphylococcus epidermidis strains responsible of non-hospital infectious endocarditis and commensal strains}; Lebeau C et al.; In order to recognize particular characteristics of pathogenic strains, epidemiologic markers of 27 Staphylococcus epidermidis strains (9 pathological and 18 commensal) were studied . Nine strains were responsible of infective endocarditis (8 on native valves, and 1 on prosthetic valve) . No case occurred after admission to hospital or surgery . Eighteen commensal strains were isolated from control subjects who had had no contact with the hospital environment and who had not received a recent antibiotic treatment . The microbiological characteristics were so diverse that no differentiation between the pathogenic strains and commensal strains could be done and no particular pathogenic clone was recognized.

Antimicrob Agents Chemother, 1993 Sep, 37(9), 1924 - 6
Evaluation of a novel fluorescence polarization immunoassay for teicoplanin; Cox H et al.; A fluorescence polarization immunoassay (FPI) for teicoplanin that uses the TDx Instrument System (Abbott, Irving, Tex.) as an automated analyzer has been developed by Innotron of Oregon Inc . and was evaluated in patients with staphylococcal infections enrolled in a clinical trial of the antibiotic . The assay proved accurate in estimating concentrations of between 5 and 100 mg/liter . The intraassay coefficient of variation was < 7.3%, while the interassay variance was < 11.6% against three commercially prepared standards at known concentrations of approximately 5, 35, and 75 mg/liter . Against routinely prepared standards at 10 concentrations between 5 and 100 mg/liter analyzed in a single run, the coefficient of variance did not exceed 4.3% . Compared with bioassay, the FPI demonstrated good correlation in terms of reliability (r = 0.909) in samples containing teicoplanin only and specificity (r = 0.916) in samples containing both teicoplanin and gentamicin . With a turnaround time of 20 min and with only 50 microliters of serum needed for estimation of the amount of drug in a sample, the FPI described here should provide a useful method of teicoplanin measurement in routine diagnostic laboratories.

Proteins, 1993 Sep, 17(1), 36 - 48
Mutational tests of the NMR-docked structure of the staphylococcal nuclease-metal-3',5'-pdTp complex; Chuang WJ et al.; In the X-ray structure of the staphylococcal nuclease-Ca(2+)-3',5'-pdTp complex, the conformation of the inhibitor 3',5'-pdTp is distorted by Lys-70* and Lys-71* from an adjacent molecule of staphylococcal nuclease (Loll, P.J., Lattman, E.E . Proteins 5:183-201, 1989) . In order to correct this crystal packing problem, the solution conformation of enzyme-bound 3',5'-pdTp in the staphylococcal nuclease-metal-pdTp complex determined by NMR methods was docked into the X-ray structure of the enzyme {Weber, D.J., Serpersu, E.H., Gittis, A.G., Lattman, E.E., Mildvan, A.S . (preceding paper)} . In the NMR-docked structure, the 5'-phosphate of 3',5'-pdTp overlaps with that in the X-ray structure . However, the 3'-phosphate accepts a hydrogen bond from Lys-49 (2.89 A) rather than from Lys-84 (8.63 A), and N3 of thymine donates a hydrogen bond to the OH of Tyr-115 (3.16 A) which does not occur in the X-ray structure (5.28 A) . These interactions have been tested by binding studies of 3',5'-pdTp, Ca2+, and Mn2+ to the K49A, K84A, and Y115A mutants of staphylococcal nuclease using water proton relaxation rate and EPR methods . Each mutant was fully active and structurally intact, as found by CD and two-dimensional NMR spectroscopy, but bound Ca2+ 9.1- to 9.9-fold more weakly than the wild-type enzyme . While the K84A mutation did not significantly weaken 3',5'-pdTp binding to the enzyme (1.5 +/- 0.7 fold), the K49A mutation weakened 3',5'-pdTp binding to the enzyme by the factor of 4.4 +/- 1.8-fold . Similarly, the Y115A mutation weakened 3',5'-pdTp binding to the enzyme 3.6 +/- 1.6-fold . Comparable weakening effects of these mutations were found on the binding of Ca(2+)-3',5'-pdTp . These results are more readily explained by the NMR-docked structure of staphylococcal nuclease-metal-3',5'-pdTp than by the X-ray structure.

Proteins, 1993 Sep, 17(1), 20 - 35
NMR docking of the competitive inhibitor thymidine 3',5'-diphosphate into the X-ray structure of staphylococcal nuclease; Weber DJ et al.; In the X-ray structure of the ternary staphylococcal nuclease-Ca(2+)-3',5'-pdTp complex, the conformation of the bound inhibitor 3',5'-pdTp is distorted by Lys-70* and Lys-71* from an adjacent molecule of the enzyme in the crystal lattice (Loll, P . J . and Lattman, E . E . Proteins 5:183-201, 1989; Serpersu, E . H., Hibler, D . W., Gerlt, J . A., and Mildvan, A . S . Biochemistry 28:1539-1548, 1989) . Since this interaction does not occur in solution, the NMR docking procedure has been used to correct this problem . Based on 8 Co(2+)-nucleus distances measured by paramagnetic effects on T1, and 9 measured and 45 lower limit interproton distances determined by 1D and 2D NOE studies of the ternary Ca2+ complex, the conformation of enzyme-bound 3',5'-pdTp is high-anti (chi = 58 +/- 10 degrees) with a C2' endo/O1' endo sugar pucker (delta = 143 +/- 2 degrees), (-) synclinal about the C3'-O3' bond (epsilon = 273 +/- 4 degrees), trans, gauche about the C4'-C5' bond (gamma = 301 +/- 29 degrees) and either (-) or (+) clinal about the C5'-O5' bond (beta = 92 +/- 8 degrees or 274 +/- 3 degrees) . The structure of 3',5'-pdTp in the crystalline complex differs due to rotations about the C4'-C5' bond (gamma = 186 +/- 12 degrees, gauche, trans) and the C5'-O5' bond {beta = 136 +/- 10 degrees, (+) anticlinal} . The undistorted conformation of enzyme-bound metal-3',5'-pdTp determined by NMR was docked into the X-ray structure of the enzyme, using 19 intermolecular NOEs from ring proton resonances of Tyr-85, Tyr-113, and Tyr-115 to proton resonances of the inhibitor . van der Waals overlaps were then removed by energy minimization . Subsequent molecular dynamics and energy minimization produced no significant changes, indicating the structure to be in a global rather than in a local minimum . While the metal-coordinated 5'-phosphate of the NMR-docked structure of 3',5'-pdTp overlaps with that in the X-ray structure, and similarly receives bifunctional hydrogen bonds from both Arg-35 and Arg-87, the thymine, deoxyribose, and 3'-phosphate are significantly displaced from their positions in the X-ray structure, with the 3'-phosphate receiving hydrogen bonds from Lys-49 rather than from Lys-84 and Tyr-85 . The repositioned thymine ring permits hydrogen bonding to the phenolic hydroxyl of Tyr-115.(ABSTRACT TRUNCATED AT 400 WORDS)

J Biomol NMR, 1993 Sep, 3(5), 607 - 12
NMR chemical shifts and structure refinement in proteins; Laws DD et al.; Computation of the 13C alpha chemical shifts (or shieldings) of glycine, alanine and valine residues in bovine and Drosophila calmodulins and Staphylococcal nuclease, and comparison with experimental values, is reported using a gauge-including atomic orbital quantum-chemical approach . The full approximately 24 ppm shielding range is reproduced (overall r.m.s.d . = 1.4 ppm) using 'optimized' protein structures, corrected for bond-length/bond-angle errors, and rovibrational effects.

Reg Immunol, 1993 Sep-Oct, 5(5), 269 - 78
In vitro culture allows splenic dendritic cells to reach their full potential for T-cell activation; Dai R et al.; Splenic dendritic cells (DCs), bone marrow-derived cells of the presumed monocyte/macrophage lineage, have been used as freshly prepared cells, as well as after overnight culture, to analyze their capacity to activate T cells in vitro with and without cognate antigen being present in the culture . Cultured DCs were found to possess potent accessory properties in vitro, displaying the abilities 1) to activate naive, syngeneic T cells in the absence of cognate antigen, and, after being derivatized with the hapten, dinitrofluorobenzene (DNFB), and 2) to sensitize unprimed, hapten-specific T cells such that the latter were able to mediate DNFB-dependent contact hypersensitivity in normal, unprimed mice . Freshly prepared splenic DCs also displayed accessory cell function; in the presence of the super-antigen, staphylococcal enterotoxin B, fresh DCs induced T-cell proliferation, and, when derivatized with DNFB, fresh DCs activated hapten-specific T cells from in vivo-primed mice . However, in both of these assays, fresh DCs were quantitatively inferior to cultured DCs . We conclude that splenic DCs can exist in two functional forms in vitro, and we propose that the functional properties displayed by freshly obtained cells correspond to the capabilities constitutively displayed by splenic DCs in the normal, unstimulated spleen . In these regards, splenic DCs appear to resemble Langerhans cells after the latter have been exposed to similar culture conditions . The possible relationships between Langerhans cells and DCs are discussed in terms of the role of the cytokine-containing microenvironment in dictating distinct functional properties of antigen-presenting cells.

Sarcoidosis, 1993 Sep, 10(2), 108 - 14
Imparied interferon-gamma production by peripheral blood mononuclear cells and effects of calcitriol in pulmonary sarcoidosis; Rottoli P et al.; Pulmonary sarcoidosis (S) is a granulomatous disease of unknown etiology characterized by spontaneous release of cytokines and 1,25-dihydroxyvitamin D3 (calcitriol) at the sites of granulomatous reaction . Stimulated by our previous findings that high levels of interferon-gamma (IFN-gamma) occur in this disease and that calcitriol reduces IFN-gamma production by peripheral blood mononuclear cells (PBMC) from normal subjects, we designed the present study to evaluate IFN-gamma production and the effect of calcitriol on the release of this cytokine by PBMC in S patients . The cells were stimulated with staphylococcal enterotoxin A (SEA) and A23187 calcium ionophore . Our results show that SEA- and A23187-stimulated PBMC from patients with S released significantly less IFN-gamma than those from control subjects . Calcitriol at 10(-6) M and 10(-9) M concentrations reduced IFN-gamma production by SEA-stimulated PBMC but this inhibitory effect was lower in S patients than controls . With A23187 we observed different behaviour at the various doses: at low doses calcitriol was as effective as in controls, but at 10(-6) M it was significantly less inhibitory in S than in healthy subjects.

J Biomed Mater Res, 1993 Sep, 27(9), 1119 - 28
Platelet-mediated adhesion of Staphylococcus epidermidis to hydrophobic NHLBI reference polyethylene; Wang IW et al.; The effects of platelets and plasma proteins on the adhesion of Staphylococcus epidermidis strain RP62A to hydrophobic NHLBI reference polyethylene was quantitatively studied using a rotating disk system to generate well-defined shear conditions simulating the hemodynamics of human blood circulation . Bacterial adhesion was quantified by adhesive coefficient, the percentage of bacteria transported to the surface that becomes adherent . The results showed that surface modification by adsorption of plasma proteins reduced the adhesion of S epidermidis as compared to the bare polymer surface . This surface modification was not sufficient to eliminate completely bacterial adhesion, even at the highest physiologic shear stress level . S epidermidis did adhere strongly to polyethylene surface modified by platelets . This is readily evident as approximately 50% of the adherent S epidermidis were bound to contact-activated platelets which occupied only 4% of the surface area . Adhesive coefficients to platelets were significantly greater than to the protein-adsorbed polyethylene surface by at least one order of magnitude (P < or = .01) across the range of physiological shear conditions investigated . These studies show that it is biologic surface modification by contact-activated platelets, and not plasma proteins, which mediates S epidermidis adhesion to polyethylene.

Scand J Immunol, 1993 Sep, 38(3), 254 - 8
Staphylococcal enterotoxin B promotes deletion and functional inactivation of CD4V beta 8-positive cells in the absence of CD8 T cells; Williams O et al.; The staphylococcal enterotoxins stimulate discrete subsets of T cells depending on their expression of particular V genes . Among these, staphylococcal enterotoxin B (SEB) vigorously stimulates V beta 8+ cells . This stimulation results in proliferation of both CD4+V beta 8+ and CD8+ T cells and eventually to anergy and clonal deletion in the former subset . We have examined the possible role of CD8+ T cells in the response of CD4+ cells to SEB, by in vivo CD8+ T-cell-depletion . We found no qualitative difference in the responses of untreated and CD8+ T-cell depleted mice to SEB; however, a small quantitative difference in deletion was observed . Thus it appears that on the whole the response of CD4+V beta 8+ T cells to SEB is independent of CD8+ T-cell effector function, although the latter may play a partial role.

Biochim Biophys Acta, 1993 Aug 20, 1158(1), 103 - 6
Two open reading frames adjacent to the Escherichia coli K-12 transketolase (tkt) gene show high similarity to the mannitol phosphotransferase system enzymes from Escherichia coli and various gram-positive bacteria; Sprenger GA; I have subcloned and sequenced the genes cmtB and cmtA of Escherichia coli K-12 which lie adjacent to the tkt gene on the chromosome . The genes cmtB and cmtA could encode a cytoplasmic protein (EIIA) and an integral-membrane protein (EIIBC), respectively, of the bacterial phospho enol pyruvate-dependent carbohydrate phosphotransferase system . High similarity to the Enzymes IIMtl of Escherichia coli K-12 (gene mtlA) and of Staphylococcus carnosus was detected, but the two genes did not complement mannitol-negative E . coli mutants without the use of a heterologous promoter.

Carbohydr Res, 1993 Aug 17, 246, 205 - 17
"Chitin Leash": a polysaccharide heterobifunctional cross-linking agent which can be cleaved by lysozyme; Guan K et al.; 6-O-{(2-Hydroxyethyl)poly(2-oxyethyl)}chitosan ("glycolchitosan") was oxidatively cleaved with nitrous acid and then partly acetylated with acetic anhydride, reacted with bromoacetyl-N-hydroxysuccinimide, and reacted further with acetic anhydride . Conditions were selected, including fractionation by size-exclusion chromatography, so that the resulting "Chitin Leash" had an estimated, average molecular weight of 10,000 (dextran standards), corresponding to a length of approximately 40 sugar residues . It possessed 0.9 terminal aldehyde and 2.6 random (presumably) side-chain bromoacetyl reactive groups per chain (average values) . As a model system, the Chitin Leash was used to crosslink staphylococcal nuclease (SNase) to ribonuclease A (RNase) with retention of 75 and 78%, respectively, of the starting enzyme activities . For this coupling, the Nase was first converted to a sulfhydryl SNase derivative which retained 74% of the activity of starting enzyme . The yields in this synthesis were: 13% Chitin Leash from glycolchitosan, 24% Chitin Leash-RNase from Chitin Leash and 45% SNase-Chitin Leash-RNase from the latter conjugate . The ratio of SNase to RNase in this conjugate was 1.0:0.94 . In a second preparation, in which {14C}acetic anhydride was used, a longer reaction time was employed for the coupling of Chitin Leash to RNase . This gave a 1.0:1.8:0.95 molar ratio of Nase: {14C}Chitin Leash: RNase, revealing multiple attachment of the {14C}Chitin Leash to RNase . The activity of the RNase in the final conjugate was 20% . The latter conjugate was approximately 70% hydrolyzed by diaminooctyl-succinyl-lysozyme, disconnecting the two enzymes while not affecting their activities.

J Immunol, 1993 Aug 15, 151(4), 1821 - 31
Urtica dioica agglutinin . A superantigenic lectin from stinging nettle rhizome; Galelli A et al.; Urtica dioica agglutinin (UDA) is an unusual plant lectin that differs from all other known plant lectins with respect to its molecular structure and its extremely low specific agglutination activity . We recently reported that this small lectin (8.5 kDa) is a T cell mitogen distinguishable from classical T cell lectin mitogens by its ability to discriminate a particular population of CD4+ and CD8+ T cells as well as its capacity to induce an original pattern of T cell activation and cytokine production . The mechanism by which UDA activates T cells was investigated and compared with the conventional T cell mitogen Con A and the known superantigen staphylococcal enterotoxin B . Our data show that T cell proliferation induced by UDA is strictly dependent on AC expressing MHC class II molecules but is not MHC restricted . This proliferation can be partially inhibited by anti-I-A or anti-I-E mAb and completely blocked by a mAb recognizing monomorphic determinants on the Ia molecule . UDA indeed binds to specific carbohydrate structures present on class II molecules . UDA-induced T cell stimulation is dependent on TCR recognition of the unprocessed intact molecule in association with various Ia molecules . T cell response to UDA is clonally expressed and correlates with particular TCR V beta gene families usage . This stimulation leads to a sixfold enrichment of V beta 8.3+ T cells within 3 days . Therefore, UDA appears to use the same molecular mechanism as structurally unrelated bacterial or retroviral superantigens and we propose that this lectin is a superantigen . UDA, which is not a pathogenicity factor, could provide a useful probe for the analysis of T cell activation by superantigens.

Blood, 1993 Aug 15, 82(4), 1230 - 8
Efficient killing of chronic B-lymphocytic leukemia cells by superantigen-directed T cells; Wallgren A et al.; In vitro studies have indicated that chronic lymphocytic leukemia of B-cell origin (B-CLL) is resistant to cytotoxic effector lymphocytes such as natural killer and lymphokine activated killer (LAK) cells . We show here that B-cell cells are sensitive to Staphylococcal enterotoxin (SE) A-directed T-cell killing . Activation of the target cells by phorbol ester (tetradecanoyl phorbol acetate, {TPA}) greatly enhances their sensitivity to lysis . In SE-dependent cellular cytotoxicity (SDCC), members of the SE superantigen family form a bridge between T cells and target cells expressing major histocompatability complex class II molecules . Binding of SEA to the T-cell-receptor V beta region induces a strong cytotoxic capacity and cytokine production . Cells from 9 B-CLL patients were cultured in the presence or absence of TPA and used as targets in a 4-hour SDCC assay using an allogeneic T-cell line as effector . At an effector:target cell ratio 30:1, 70% to 80% of TPA-induced B-CLL cells were killed . Even at the effector:target ratio of 3:1, 47% +/- 6% of TPA-activated B-cell cells were lysed compared with 13% +/- 2% of resting cells (P < .001) . A T-cell line established from a B-CLL patient killed autologous tumor cells as efficiently as allogeneic effectors . SEA-directed T cells were far more lytic to B-CLL cells compared with LAK cells or lectin (phytohemagglutinin-directed T cells . Mechanisms of SDCC lysis were investigated . Effector plus target cell supernatants contained high levels of tumor necrosis factor (TNF)-alpha and interferon-gamma, but these supernatants were not directly toxic to B-CLL cells in short term culture . High concentrations of recombinant TNF-alpha or TNF-beta had no lytic effect . Addition of neutralizing anti-TNF-alpha and anti-TNF-beta antibodies into the SDCC assay did not inhibit SEA-directed T-cell killing . TPA-activated B-CLL cells showed a 1.2- to 13-fold increased expression of the adhesion molecules intercellular adhesion molecule-1 (ICAM-1), lymphocyte function-associated antigen (LFA)-1, and LFA-3, whereas expression of HLA class II molecules increased up to 5 times . The expression of CD72, CD40, and BB-1/B7 increased 1.8 to 4.5 times . The role of these surface molecules in SDCC was analyzed in blocking experiments with monoclonal antibodies . Antibodies to ICAM-1, CD18, and HLA-DR abolished the cytotoxicity, and a substantial reduction was seen with antibody to CD72.(ABSTRACT TRUNCATED AT 400 WORDS)

J Immunol, 1993 Aug 15, 151(4), 1938 - 49
IL-12 induces the production of IFN-gamma by neonatal human CD4 T cells; Wu CY et al.; A major difference between "naive" and "memory" or "effector" Th cells is the spectrum of cytokines that they are capable of producing . After stimulation naive cells produce only IL-2, whereas memory cells produce several cytokines including IFN-gamma and IL-4 . Using umbilical cord blood-derived CD4 T cells as a source of naive T cells, we first report that these cells are capable of producing large amounts of IFN-gamma when cultured with low concentrations of IL-12 . The response is time- and dose-dependent, and it is observed at the protein and mRNA levels . IL-12 also induces neonatal CD4 T cells to produce lymphotoxin but not IL-2, TNF-alpha, or IL-4 . The production of IFN-gamma by IL-12-stimulated neonatal T cells is associated with a small but significant T cell activation evidenced by DNA synthesis and by the expression of the activation markers CD25, CD71, and HLA-DR; moreover, it is inhibited by hydrocortisone, cyclosporin A, and transforming growth factor-beta . The response to IL-12 is enhanced and is much more rapid when CD4 T cells are cultured in the presence of accessory cells or of exogenous IL-1, IL-2, or TNF-alpha . Using a three-step culture system, we next show that IL-12 induces the maturation of resting naive CD4 T cells into cells producing both IL-2 and IFN-gamma but not IL-4 upon stimulation with PMA and ionomycin . Endogenously produced IFN-gamma plays a role in this IL-12-induced T cell maturation, as shown by the inhibitory effect of neutralizing IFN-gamma antibodies . Finally, we show that IL-12 supports the production of IFN-gamma during primary stimulation of neonatal T cells via the CD3/TCR complex by means of either immobilized anti-CD3 mAb or superantigen-coated (Staphylococcus enterotoxin B) fixed L cell transfectants expressing HLA-DR . It is suggested that IL-12 is involved in the selection of Th1 type immune responses.

FEBS Lett, 1993 Aug 9, 328(1-2), 49 - 54
13C NMR study of the mode of interaction in solution of the B fragment of staphylococcal protein A and the Fc fragments of mouse immunoglobulin G; Kato K et al.; The mode of interaction of the B domain (FB) of staphylococcal protein A and the Fc fragments of mouse immunoglobulin G (IgG) has been investigated by 13C NMR spectroscopy . Mouse IgG1, IgG2a, and IgG2b proteins have been selectively labeled with 13C at the carbonyl carbon of His, Met, Trp or Tyr residue and used to prepare the corresponding Fc fragments by limited proteolysis . Site-specific resonance assignments have been made for each of these Fc analogues . FB was reported to form two contacts (contact 1 and contact 2) with human Fc in the crystal {Biochemistry 20 (1981) 2361-2370} . Comparisons of the chemical shift data of the Fc fragments observed in the absence and presence of FB have led us to conclude that in solution contact 1 is responsible for the formation of the Fc-FB complexes.

J Mol Biol, 1993 Aug 5, 232(3), 718 - 24
The phase transition between a compact denatured state and a random coil state in staphylococcal nuclease is first-order; Gittis AG et al.; Three mutants of staphylococcal nuclease containing a tryptophan substitution have been examined in the full length (149 residues) protein and in a large fragment (residues 1 to 136) . The large fragments are not in the native state and are a good model of the denatured state . However, these large fragments do show signs of residual structure that breaks down upon titration with guanidine hydrochloride . They share some similarities with what has become known as the molten globule state . The thermal unfolding of these mutant fragments was followed by tryptophan fluorescence . Tryptophan fluorescence was treated as an order parameter and analyzed to determine the order of the observed transition . The critical exponent of the order parameter as the transition temperature is approached is significantly higher than the value of 1/2 predicted by mean field theory for a second-order transition and is similar to that observed for the transition of the full length, wild-type, protein . This is strong evidence that the breakdown of this intermediate compact denatured state is a cooperative, first-order phenomenon.

Clin Nucl Med, 1993 Aug, 18(8), 682 - 4
Discordance between F-18 fluorodeoxyglucose uptake and contrast enhancement in a brain abscess; Meyer MA et al.; A 29-year-old human immunodeficiency virus-negative intravenous drug abuser with a right hemispheric staphylococcal brain abscess underwent PET imaging of 18F-fluorodeoxyglucose (FDG) brain uptake . Diffuse right cortical hypometabolism was noted, as well as crossed cerebellar diaschisis . Unlike previous PET findings on FDG uptake in a brain abscess, however, the most intense uptake of FDG was found within the abscess and not in the contrast-enhancing walls.

FEMS Immunol Med Microbiol, 1993 Aug, 7(2), 169 - 74
Stimulation of rat spleen cells by staphylococcal enterotoxins; Holbrook MR et al.; There is much interest in staphylococcal enterotoxins as T cell mitogens in humans, mice and rabbits . Rat spleen cells were shown to proliferate in response to staphylococcal enterotoxins A and B and toxic shock syndrome toxin-1 at concentrations (5 to 500 ng ml-1) which also stimulate mouse spleen cells . The proliferative response to all these enterotoxins was inhibited by cyclosporin A, indicating the response to be predominantly that of T cells . These results indicate that the rat provides another convenient model for the analysis of T cell responses to enterotoxins.

Int Immunol, 1993 Aug, 5(8), 957 - 64
Targeted disruption of the MHC class II Aa gene in C57BL/6 mice; Kontgen F et al.; The MHC class II gene Aa was disrupted by targeted mutation in embryonic stem (ES) cells derived from C57BL/6 mice to prevent expression of MHC class II molecules . Contrary to previous reports, the effect of the null-mutation on T cell development was investigated in C57BL/6 mice, which provide a defined genetic background . The complete lack of cell surface expression of MHC class II molecules in B6-Aa0/Aa0 homozygous mutant mice was directly demonstrated by cytofluorometric analysis using anti-Ab and anti-Ia specific mAbs . Development of CD4+CD8- T cells in the thymus was largely absent except for a small population of thymocytes expressing high levels of CD4 together with low amounts of CD8 . The majority of these cells express the TCR at high density . Although mature CD4+CD8- T cells were undetectable in the thymus, some T cells with a CD4+CD8-TCRhigh phenotype were found in lymph nodes and spleen . Peripheral T cells from the mutant mice can be polyclonally activated in vitro with the mitogen concanavalin A . However, they could not be stimulated with staphylococcal enterotoxin B in autologous lymphocyte reactions, thereby demonstrating the absence of MHC class II expression in these mice . Peripheral B cells in B6-Aa0/Aa0 mutants were functional and responded to the T cell independent antigen levan by the production of antigen-specific IgM antibodies similar to wild-type cells . The B6-Aa0/Aa0 mutant mice described in this study represent an important tool to investigate the involvement of MHC class II molecules in lymphocyte maturation and the immune response.

Int Immunol, 1993 Aug, 5(8), 929 - 37
Induction of unresponsiveness to the superantigen staphylococcal enterotoxin B: cyclosporin A resistant split unresponsiveness unfolds in vivo without preceding clonal expansion; Heeg K et al.; The continuous presence of antigen and powerful immune responses (exhaustive cell proliferation) of ligand reactive T cells are currently thought to condition clonal deletion and/or induction of unresponsiveness to endogenous or exogenous superantigens (SAg) . Here we report that in vivo induction of unresponsiveness to the SAg staphylococcal enterotoxin B (SEB) can be an immediate process . Within ours a large portion of ligand reactive V beta 8+ T cells becomes clonally deleted by apoptosis . In parallel, the remaining V beta 8+ T cells are unresponsive to SEB, yet at the same time express functional IL-2 receptors (IL-2R) and thus are highly responsive to the growth promoting effects of IL-2 . In a subsequent step refractory IL-2R+V beta 8+ T cells undergo a wave of cell proliferation for 48 h, presumably driven by IL-2 . Thereafter a large proportion of V beta 8+ T cells succumb to apoptosis, the remaining cells display the hallmarks of split unresponsiveness, i.e . they display a selective failure to produce IL-2 upon SEB stimulation in vitro combined with a preserved capability to express functional IL-2R . Early deletion and induction of unresponsiveness to SEB are cyclosporin A (CsA) resistant, while clonal expansion with subsequent cell deletion is blocked by CsA, yet the development of split unresponsiveness is not impaired by CsA . The results suggest that IL-2 driven growth of refractory T cells may mimic powerful immune responses of ligand reactive V beta 8+ T cells . Since unresponsiveness to SEB precedes in vivo expansion, the results as such question the concept of 'exhaustive cell proliferation' as a prerequisite for induction of unresponsiveness.(ABSTRACT TRUNCATED AT 250 WORDS)

Biotechnol Appl Biochem, 1993 Aug, 18 ( Pt 1), 93 - 102
Reversible enzymic protection of the alpha-amino group of amino acid derivatives using an aminopeptidase A; Yoshpe-Besancon I et al.; In previous papers we have reported that an aminopeptidase A (EC 3.4.11.7) purified from Staphylococcus chromogenes was able to catalyse the introduction of L-malic acid at the N-terminus of Tyr and Phe derivatives . We now show that this enzyme can be used for selective alpha-amino protection of derivatives of probably all amino acids, except Gly and Pro, by the malyl group . The following L-malyl derivatives were synthesized in thermodynamically controlled reactions with yields ranging from 4 to 47%: L-malyl-Tyr-OEt, -ALA-OMe, -Ser-OEt, -Lys-OEt, -Phe-OMe, -Met-NH2, -Glu-MH2, Arg-NH2, -Tye-NH2, -Val-NH2, -Ala-Phe and -Ala-Phe-NH2 (OEt and OMe are ethyl and methyl esters respectively) . The reactions were monitored by reverse-phase h.p.l.c.; the products were quantified by amino acid analysis, and their structure was confirmed by m.s . No synthesis was obtained with Gly and Pro derivatives as nucleophiles . The effects of pH, temperature, enzyme concentration, nucleophile concentration, reaction time and addition of an organic co-solvent were studied . An important shift towards synthesis was obtained by carrying out the reactions at 55 degrees C in the presence of 55% organic co-solvent Triglyme (2,4,8,11-tetraoxadodecane) {8-60-fold increase in Ksyn . ({product} {acyl-donor}-1 {nucleophile}-1)}.

J Dairy Res, 1993 Aug, 60(3), 299 - 306
Effect of caprine arthritis-encephalitis virus infection on milk cell count and N-acetyl-beta-glucosaminidase activity in dairy goats; Ryan DP et al.; Bacteriology, somatic cell counts (SCC) and N-acetyl-beta-glucosaminidase (NAGase) activity determinations were conducted on milk samples collected from does in three dairy herds with caprine arthritis-encephalitis virus (CAEV) infection . In two herds, CAEV-infected does were more likely to have a subclinical bacterial infection of the udder than CAEV-free does (P < 0.05) . Does with CAEV but no bacterial udder infection had significantly greater mean SCC and NAGase activity than CAEV-free does without udder infection (P < 0.01) . In two herds, changes in milk SCC and NAGase associated with CAEV infection were similar to those produced by coagulase-negative staphylococcal infections . The findings confirm that indirect indicators of bacterial mastitis infection may have reduced specificity in dairy goat herds with CAEV.

J Exp Med, 1993 Aug 1, 178(2), 713 - 22
T cell receptor interaction with peptide/major histocompatibility complex (MHC) and superantigen/MHC ligands is dominated by antigen; Ehrich EW et al.; While recent evidence strongly suggests that the third complementarity determining regions (CDR3s) of T cell receptors (TCRs) directly contact antigenic peptides bound to major histocompatibility complex (MHC) molecules, the nature of other TCR contact(s) is less clear . Here we probe the extent to which different antigens can affect this interaction by comparing the responses of T cells bearing structurally related TCRs to cytochrome c peptides and staphylococcal enterotoxin A (SEA) presented by 13 mutant antigen-presenting cell (APC) lines . Each APC expresses a class II MHC molecule (I-Ek) with a single substitution of an amino acid residue predicted to be located on the MHC alpha helices and to point "up" towards the TCR . We find that very limited changes (even a single amino acid) in either a CDR3 loop of the TCR or in a contact residue of the antigenic peptide can have a profound effect on relatively distant TCR/MHC interactions . The extent of these effects can be as great as that observed between T cells bearing entirely different TCRs and recognizing different peptides . We also find that superantigen presentation entails a distinct mode of TCR/MHC interaction compared with peptide presentation . These data suggest that TCR/MHC contacts can be made in a variety of ways between the same TCR and MHC, with the final configuration apparently dominated by the antigen . These observations suggest a molecular basis for recent reports in which either peptide analogues or superantigens trigger distinct pathways of T cell activation.

Bol Med Hosp Infant Mex, 1993 Aug, 50(8), 570 - 6
{Neonatal conjunctivitis caused by Chlamydia trachomatis}; Yescas-Buendia G et al.; 32 newborns with neonatal Chlamydia trachomatis conjunctivitis were reported . Diagnosis was carried out through immunofluorescent monoclonal antibody of conjunctiva scraping staining; 37 conjunctiva samples were taken from same number of newborn patients not responds to topical antibiotic treatment . The sample came out from two different third level institutions with maternal facilities and attending more than five thousand deliveries per year each one of them . Were studied incidence and clinical picture from neonatal C . trachomatis conjunctivitis . Positive immunofluorescent and conjunctive culture of secretion to C . trachomatis in the sample were 86 per cent (32 out of 37) . 19 of the newborns acquired Staphylococcus associated to C . trachomatis (59%): nine with S . aureus in six Staphylococcus negative coagulase was isolated and four with the latest two . Out of 32 patients who demonstrated positive cultures to C . trachomatis (86%), 22(69%) were males and ten (31%) were females . Significant proportion of newborns were identified as small for gestational age . 18 of them were born by natural way and 14 by cesarean section . In 16/32 (50%) had interstitial pneumonia by Chlamydia . The main clinical findings were stated as: conjunctiva exudate in different stages including purulent secretion and oedema or inflammation of the ophthalmic conjunctiva . Those newborns where topical therapy did not irradiate the organism and demonstrated clinical picture persistence or relapse and diagnosis of C . trachomatis infection, systemic treatment with erythromycin and topic tetracycline were installed, disappearing all symptoms . Maternal history related to neonatal disease were mainly: endocervical infection, miscarriages and or preterm delivery.

Arch Ophthalmol, 1993 Aug, 111(8), 1117 - 22
Tissue plasminogen activator and Staphylococcus epidermidis endophthalmitis; Ryan EH et al.; OBJECTIVE: To determine whether intraocular administration of tissue plasminogen activator (tPA) speeds clearance of inflammatory debris or prevents fibroproliferative complications in an animal model of endophthalmitis . METHODS: Aphakic rabbits were given an intraocular dose of Staphylococcus epidermidis organisms known to cause moderate inflammation and to self-sterilize . They were then randomized to receive either tPA or saline injections 2 and 3 days after inoculation . All eyes were graded by one masked clinician seven times, 1 to 28 days after infection . Vitreous samples from selected eyes were cultured . RESULTS: Treated and control eyes were found to have no significant difference in inflammatory scores . Although the eyes treated with tPA had more retinal detachments and more positive cultures than control eyes, these numbers were not statistically significant (P = .44 to .71) . CONCLUSION: Fibrinolysis with intraocular tPA does not accelerate clearance of inflammation nor decrease fibroproliferative complications in this animal model of endophthalmitis.

Eur J Immunol, 1993 Aug, 23(8), 1884 - 8
Allogeneic recognition of class I molecules: anti-H-2Ld repertoire of H-2b mice includes T cells recognizing mutant class II H-2b (Abm12) molecules; Frangoulis B et al.; Two major histocompatibility complex (MHC) class I-reactive T cell clones derived from H-2b mice, generated against the allogeneic Ld molecule, were found to recognize the H-2b class II mutant Abm12 molecule as well . In addition, these clones also recognize the class II A(s) molecule, and display a class II-dependent reactivity to staphylococcal enterotoxin B . Neither the class I nor the class II alloreactivities of the clones were found to be dependent on other MHC molecules . Both clones express CD4+CD8- phenotypes . The CD4 molecule appears to be involved in their class II reactivity, while little or no role for CD4 could be detected in the class I reactivity . This is the first report of a class I/class II cross-reactivity being mediated by CD4+ T cells . The structural basis for this cross-reactivity is discussed.

Arthritis Rheum, 1993 Aug, 36(8), 1061 - 9
The repertoire of rheumatoid factor-producing B cells in normal subjects and patients with rheumatoid arthritis; He X et al.; OBJECTIVE . To compare the B cell repertoire of normal individuals and patients with rheumatoid arthritis (RA) and, specifically, to identify precursor B cells with the potential to secrete rheumatoid factor (RF) and to understand the T helper cell requirements for the production of this autoantibody . METHODS . Frequencies of precursors of IgM-, IgG-, and RF-producing B cells were measured in a limiting-dilution system . Two distinct sources of T cell help were compared . T cell help was provided by anti-CD3-activated CD4+ human T cell clones, or T cell-B cell interaction was facilitated by the bacterial super-antigen staphylococcal enterotoxin D (SED) . RESULTS . A subset of 2-14% of peripheral blood B cells secreted IgM and IgG in SED-driven cultures . The SED-responsive B cell subpopulation was present at 10 times higher frequency in normal donors compared with RA patients . However, the repertoires were very similar, particularly for RF+ precursors, which represented approximately one-third of all SED-responsive B cells . In normal individuals, most of these RF+ precursor B cells did not respond to anti-CD3-activated T helper cells, with only a very small fraction of B cells activated by anti-CD3-driven helper cells maturing into RF-secreting B cells (from 1 of 182 to 1 of 889 IgM-producing B cells) . This subset was expanded approximately 50-fold in RA patients . CONCLUSION . Normal subjects and RA patients share a pool of B cells which secrete RF when activated in the presence of SED and T helper cells . These B cells are frequent and obviously anergic in normal individuals . The B cell subset with the potential to produce RF when help is provided in noncognate T-B interaction (anti-CD3-driven T cells) is considerably expanded in RA patients, probably reflecting an increased responsiveness of such B cells to helper signals.

Ophthalmology, 1993 Aug, 100(8), 1218 - 24
Pseudophakia for traumatic cataracts in children; Koenig SB et al.; PURPOSE: The purpose of this prospective study is to evaluate the postoperative visual acuity, refractive error, intraocular pressure, and status of the posterior capsule in children with traumatic cataracts who undergo extracapsular cataract extraction and insertion of a posterior chamber lens . METHODS: Extracapsular cataract extraction and primary endocapsular fixation of a posterior chamber lens implant were performed in eight children (age range, 4-17 years) with unilateral traumatic cataracts . RESULTS: There were no intraoperative complications, and seven of eight eyes achieved 20/40 or greater spectacle visual acuity during an average follow-up interval of 10 months (range, 5-20 months) . The average postoperative spherical equivalent refractive error was +0.33 diopter (D) (range, -2.25 to +2.12 D); the average postoperative anisometropia was approximately 1 D (range, 0-2.25 D) . In one patient, a coagulase-negative staphylococcal endophthalmitis developed 10 days after surgery . In three eyes that had opacified posterior capsules, YAG laser capsulotomy was performed . CONCLUSIONS: These preliminary results suggest that intraocular lens (IOL) implantation may be a safe and effective method of optical correction for children with traumatic cataracts.

J Exp Med, 1993 Aug 1, 178(2), 633 - 42
Small amounts of superantigen, when presented on dendritic cells, are sufficient to initiate T cell responses; Bhardwaj N et al.; Dendritic cells are potent antigen-presenting cells for several primary immune responses and therefore provide an opportunity for evaluating the amounts of cell-associated antigens that are required for inducing T cell-mediated immunity . Because dendritic cells express very high levels of major histocompatibility complex (MHC) class II products, it has been assumed that high levels of ligands bound to MHC products ("signal one") are needed to stimulate quiescent T cells . Here we describe quantitative aspects underlying the stimulation of human blood T cells by a bacterial superantigen, staphylococcal enterotoxin A (SEA) . The advantages of superantigens for quantitative studies of signal one are that these ligands: (a) engage MHC class II and the T cell receptor but do not require processing; (b) are efficiently presented to large numbers of quiescent T cells; and (c) can be pulsed onto dendritic cells before their application to T cells . Thus one can relate amounts of dendritic cell-associated SEA to subsequent lymphocyte stimulation . Using radioiodinated SEA, we noted that dendritic cells can bind 30-200 times more superantigen than B cells and monocytes . Nevertheless, this high SEA binding does not underlie the strong potency of dendritic cells to present antigen to T cells . Dendritic cells can sensitize quiescent T cells, isolated using monoclonals to appropriate CD45R epitopes, after a pulse of SEA that occupies a maximum of 0.1% of surface MHC class II molecules . This corresponds to an average of 2,000 molecules per dendritic cell . At these low doses of bound SEA, monoclonal antibodies to CD3, CD4, and CD28 almost completely block T cell proliferation . In addition to suggesting new roles for MHC class II on dendritic cells, especially the capture and retention of ligands at low external concentrations, the data reveal that primary T cells can generate a response to exceptionally low levels of signal one as long as these are delivered on dendritic cells.

Chest, 1993 Aug, 104(2), 639 - 40
Effect of tracheal dilatation and rupture on mechanical ventilation using a low-pressure cuff tube; Luna CM et al.; We report the case of a 36-year-old woman who suffered tracheal dilatation and rupture despite careful monitoring of intracuff pressure . Surgical manipulation, postoperative mediastinitis, and bacterial staphylococcal tracheitis may be involved in the development of this complication.

Crit Care Med, 1993 Aug, 21(8), 1124 - 31
Intraoperative and postoperative effects of vancomycin administration in cardiac surgery patients: a prospective, double-blind, randomized trial; Romanelli VA et al.; OBJECTIVES: In response to an increased frequency of Staphylococcus epidermidis infections in postoperative cardiac surgery patients, antibiotic prophylaxis was changed to include both vancomycin and cefazolin pre- and intraoperatively . Subsequent to the addition of vancomycin prophylaxis, clinical impression and retrospective analysis supported a correlation between vancomycin administration and post-cardiopulmonary bypass norepinephrine use . DESIGN: A prospective, double-blind, randomized study . SETTING: Tertiary care center in a university hospital . PATIENTS: A total of 58 patients undergoing elective coronary artery bypass surgery under high-dose fentanyl anesthesia . INTERVENTIONS: Patients were randomized to receive cefazolin and either vancomycin or normal saline pre-, intra-, and postoperatively in a double-blinded protocol . MEASUREMENTS AND MAIN RESULTS: Hemodynamic profiles and doses of administered vasoactive agents were calculated and recorded for all patients for both intra- and postoperative time periods . Hypotension consistent with vasodilation was treated with a norepinephrine infusion . The rate and frequency of norepinephrine infusions were tabulated for both groups . Hemodynamic profiles that were obtained after the administration of the initial dose of vancomycin or normal saline and before the induction of general anesthesia and those profiles obtained after the induction of general anesthesia until the initiation of cardiopulmonary bypass showed no difference between groups and no evidence of vasodilation secondary to vancomycin administration . However, subsequent doses of vancomycin in the intra- and postoperative periods were associated with a significantly greater frequency of norepinephrine infusions to maintain normal hemodynamic indices . In the vancomycin group, 50% of patients received a norepinephrine infusion in the intra- and/or postoperative period as compared with 14% in the normal saline group (p < .01) . Furthermore, the group of patients who received vancomycin and subsequently required a norepinephrine infusion had significantly lower mean systolic arterial pressure, mean arterial pressure, and systemic vascular resistance as compared with all other groups . There were no differences between groups in the use of vasopressors (other than norepinephrine) or fluid balance . CONCLUSIONS: The results show that a significantly greater number of patients who received vancomycin required a norepinephrine infusion and that, despite norepinephrine infusion therapy, systemic vascular resistance was not normalized in this group of patients . The study supports the conclusion that perioperative administration of vancomycin in cardiac surgery patients may result in hypotension requiring the use of a vasopressor in an attempt to normalize hemodynamic indices.

Infect Immun, 1993 Aug, 61(8), 3342 - 50
Interleukin-1 (IL-1) receptor antagonist prevents Staphylococcus epidermidis-induced hypotension and reduces circulating levels of tumor necrosis factor and IL-1 beta in rabbits; Aiura K et al.; Similar to shock in gram-negative sepsis, shock from gram-positive organisms is mediated, in part, by tumor necrosis factor (TNF) and interleukin-1 (IL-1) . In the present study, rabbits were infused with IL-1 receptor antagonist (IL-1ra) prior to and during Staphylococcus epidermidis-induced hypotension . After injection of bacteria, a maximal fall in mean arterial pressure to -42% below baseline occurred at 200 min in vehicle-treated animals compared with a nonsignificant decrease of only 7% in the IL-1ra-treated group (P < 0.01, vehicle versus IL-1ra) . A similar attenuation was observed in the fall in systemic vascular resistance (P < 0.05) . After the injection of S . epidermidis, TNF levels rose to a peak elevation of 475 +/- 160 U/ml in vehicle-treated rabbits, but in rabbits receiving IL-1ra, maximal TNF levels rose only to 85 +/- 23 U/ml (P < 0.01) . Plasma IL-1 beta reached maximal concentrations at 180 min of 364 +/- 71 pg/ml in vehicle-treated animals but only 145 +/- 12 pg/ml in rabbits given IL-1ra (P < 0.05) . The reductions in TNF and IL-1 were not due to interference by IL-1ra in the respective assays . In vitro, IL-1ra inhibited S . epidermidis-induced TNF from mononuclear cells by 31% +/- 11%, from spleen cells by 17% +/- 4% (P < 0.05), and from whole blood by 42% +/- 17% . Despite the near reversal of the fall in mean arterial pressure and systemic vascular resistance in IL-1ra-treated rabbits, leukopenia and thrombocytopenia were unaffected . These results demonstrate that IL-1ra blocks shock-like hemodynamic parameters and reduces circulating IL-1 and TNF levels in a model of gram-positive sepsis.

Khirurgiia (Mosk), 1993 Aug, (8), 62 - 6
{Treatment of hematogenic osteomyelitis in newborns}; Kononov VS et al.; The authors studied the immunobiological condition of the newborn's organism and the process of bone structure reparation before and after direct immune hemotransfusions and transplantation of bone marrow with the stroma in a mixture with antibiotics into the focus of osteomyelitis in the bone of newborn infants with consideration for the clinical manifestations of the disease, the stage of osteomyelitis, and the efficacy of the applied treatment . The authors examined 215 newborns with acute hematogenous osteomyelitis . The predominant site of localization of acute hematogenous osteomyelitis in the newborn infants were the epimetaphyseal (54.5%) and metaphyseal (39.6%) parts of the long tubular bones . The donors were immediate relatives compatible according to the ABO system and the rhesus factor, who underwent complete examination for HIV infection, the Australia antigen, and the Wasserman reaction, and who were immunized preliminarily with the staphylococcus anatoxin . The authors note the favorable immediate and late-term results of treatment which were confirmed by radiological restoration of the bone structure . The immunological values testify to increase of cellular and humoral immunity . Study of the late-term results of treatment confirm the decrease of the number of orthopedic complications.

J Antimicrob Chemother, 1993 Aug, 32(2), 267 - 78
In-vitro characteristics of glycopeptide resistant strains of Staphylococcus epidermidis isolated from patients on CAPD; Sanyal D et al.; The low-level resistance of three clinical isolates of Staphylococcus epidermidis to glycopeptide antibiotics was found to be constitutive, not inducible, and was not increased by passage in the presence of either vancomycin or teicoplanin . There was no loss of resistance on repeated passage in antibiotic-free broth . In contrast, the susceptibility to these antibiotics declined for S . epidermidis NCTC 6513 that been sequentially passaged in either vancomycin or teicoplanin whereas the variants reverted to being susceptible on further passage in antibiotic-free broth . Antibiotic activity was almost completely abolished when cultures of the resistant S . epidermidis strains were exposed overnight to sub-MIC concentrations . No evidence of drug-modifying activity was obtained . Experiments of antibiotic-binding activity indicated that the resistant strains exhibited an increased ability to sequester antibiotics which was particularly rapid in stationary phase cultures when most of the antibiotic activity disappeared from the growth medium within 30 min of exposure to the drugs . Teicoplanin was sequestered more efficiently than vancomycin and some loss of activity was also observed when stationary phase cultures of S . epidermidis NCTC 6513 were exposed to glycopeptides . These results suggest that glycopeptide-resistant isolates of S . epidermidis are able to bind large amounts of these antibiotics, possibly at sites unassociated with the D-alanyl-D-alanine target, and that teicoplanin is bound more avidly than vancomycin.

Clin Nephrol, 1993 Aug, 40(2), 106 - 13
Effect of dialysis on the clearance of Staphylococcus epidermidis from the peritoneal cavity: an experimental evaluation; Rowe L et al.; Current information on the effect of peritoneal dialysis on host defenses in the peritoneal cavity is limited to in vitro studies . In the present study, clearance of Staphylococcus epidermidis from the abdominal cavity was assessed in an animal model undergoing peritoneal dialysis . In non-manipulated subjects, challenges of up to 10(8) viable microorganisms were cleared from the peritoneal cavity over a period of 24-48 hours . Cannula implantation, short- and long-term dialysis and the presence of excessive amounts of fluid in the peritoneal cavity did not affect the clearance rate . Presentation of the bacterial challenge, either as a bolus or via a slow delivery system, likewise had no effect on clearance rates . The results suggest that microbial trophism and the characteristics of the invading pathogen may be more critical determinants of the outcome of an infectious challenge to the peritoneal cavity than the status of the cellular and humoral defense systems.

Int J Hematol, 1993 Aug, 58(1-2), 63 - 72
Single daily ceftriaxone and tobramycin in the empirical management of febrile neutropenic patients: a randomised trial; Gibson J et al.; A single-institution, randomised pilot trial was conducted to compare the clinical efficacy, microbiological efficacy and possible toxicity of empirical single daily antibiotic administration in febrile neutropenic patients with haematologic disorders (absolute neutrophil count < 1 x 10(9)/l) . Upon the development of signs of sepsis, patients received either single daily dose tobramycin (5 mg/kg per day) plus ceftriaxone (2 g/day) (C + T, n = 47) or tobramycin (1.5 mg/kg, every 8 h) plus azlocillin (4 g, every 6 h) (A + T, n = 45) . In addition, flucloxacillin (1-2 g, every 4 h) could be added if there was clinical suspicion of staphylococcal infection (17 in each arm) . Analysis was performed for the whole group and for the subset which did not receive flucloxacillin . When evaluated at 96 h, 62% of patients randomised to C + T and 67% randomised to A + T had responded (95% confidence interval (CI) for the difference in rates, -25% to +15%) . Ninety-six hour response rates for those who did not receive flucloxacillin were 73% and 78%, respectively (95% CI, -17% to +27%) . Overall, 42 (89%) and 41 (91%) patients, respectively, eventually became afebrile (95% CI, -14 to 10%) and there was no evidence of altered renal function or electrolyte imbalance in patients randomised to single daily antibiotic therapy compared with the conventional (multi-daily dose) arm . Within 10 days of antibiotic commencement there was 1 death in the C + T arm and 4 deaths in the A + T arm, although overall there were 4 deaths in each arm . Our results suggest that single daily empirical antibiotic therapy with tobramycin and ceftriaxone is efficacious and is not associated with an increased incidence of renal dysfunction or electrolyte imbalance compared with conventional administration schedules of azlocillin plus tobramycin . Single daily therapy has the potential to lead to savings in nursing-staff time and materials and may well contribute to an improved quality of life for febrile neutropenic patients.

Am J Vet Res, 1993 Aug, 54(8), 1317 - 21
Cefazolin antibacterial activity and concentrations in serum and the surgical wound in dogs; Rosin E et al.; An antibiotic selected for surgical antimicrobial prophylaxis must be present in the surgical site throughout the operation in concentration sufficient to prevent growth of contaminating pathogens . The antimicrobial spectrum, minimal toxicity, and low cost of cefazolin make this first-generation cephalosporin a logical choice for antimicrobial prophylaxis in small animal surgical procedures in which the normal microbiologic flora of skin and gastrointestinal tract are the most likely pathogens . Pharmacokinetic variables of cefazolin were determined in serum and surgical wounds in dogs . Drug concentration in interstitial fluid of muscle biopsy specimens taken at random from wound surfaces and in postoperative wound fluid samples were determined . Effective surgical wound concentration of cefazolin was defined as 4 micrograms/ml, a concentration that inhibited the growth in vitro of 100% of staphylococcal and 80% of Escherichia coli clinical isolates . After IV and SC administrations, cefazolin equilibrated rapidly between serum and the surgical wound, and concentrations in the 2 sites decreased in parallel . With a bolus dose of 20 mg/kg of body weight given IV at the beginning of surgery and repeated by SC administration at 6 hours, cefazolin concentration in the surgical wound remained > 4 micrograms/ml for longer than 12 hours.

Alcohol Clin Exp Res, 1993 Aug, 17(4), 822 - 7
Immune function in offspring of nonhuman primates (Macaca nemestrina) exposed weekly to 1.8 g/kg ethanol during pregnancy: preliminary observations; Grossmann A et al.; A preliminary investigation of immune host response was conducted in a group of fetal alcohol-exposed nonhuman primates (Macaca nemestrina) who were part of a broader ongoing study of ethanol teratogenicity . The mothers of the offspring received weekly oral doses of ethanol (1.8 g/kg) for the first 3 or 6 or the entire 24 weeks of gestation . A control group received sucrose solution weekly throughout pregnancy . Four of the 18 ethanol-exposed animals (22%) died or were euthanized after infectious disease or failure to thrive during the first year of life; none of the seven control animals died . This imbalance in survival prompted the present review of immune function in the remaining offspring . Parameters assessed included: (1) white blood cell count (WBC), (2) peripheral blood leucocyte subsets (CD4+, CD8+, CD20+, and CD11c+), (3) T-cell proliferation after activation with phytohemagglutinin (PHA), staphylococcus enterotoxin B (SEB), and tetanus toxoid (TT), (4) phagocytic activity of monocytes, and (5) serum immunoglobulin levels and serum antibody titers after TT vaccination . Mean T-cell proliferation to TT was significantly decreased (p = 0.01) in all ethanol-exposed animals relative to controls, with near-significant decreases (p = 0.06) in response to SEB in the ethanol-exposed animals . Lymphocyte proliferation in response to PHA was not altered . Ethanol-exposed animals had significantly lower TT titers than controls after initial vaccination and booster . WBC, leukocyte subsets, serum immunoglobulins, and monocyte phagocytic activity were not significantly different from control values . These preliminary observations suggest that T-cell proliferation and antigen-specific memory responses may be altered in offspring exposed to weekly doses of ethanol in utero and warrant further evaluation for confirmation.

Acta Orthop Scand, 1993 Aug, 64(4), 417 - 20
Closed suction drainage after hip arthroplasty . Prospective study of bacterial contamination in 81 cases; Overgaard S et al.; In a prospective study we analyzed the volume of drainage, the contamination of the drain track, and drain tip in 81 primary total hip arthroplasties in 78 patients . The drain was removed when the drainage from midnight to the following morning was 20 mL or less . The drainage in the first 12 h and in total was reduced in cases with a drain period of 24 h, compared to cases with a drain period of 48 and 72 h . 4 cases had a positive culture from the wound before closure . 5 cases had a positive culture from the tip of the drain, and 6 from the drain track . The most frequently isolated microorganism was coagulase-negative Staphylococcus . The positive cultures from the drain track and tip were not correlated to the duration of drainage . 68 drains were removed within 48 h with no risk of developing wound complications.

AACN Clin Issues Crit Care Nurs, 1993 Aug, 4(3), 475 - 83
Sternal wound infections; Vaska PL; Sternal wound infections are a major cause of morbidity and mortality in patients undergoing cardiac surgery . They occur in 1% to 3% of patients who undergo open-heart surgery and carry a 20% to 40% mortality rate . Sternal infections can range from minor, superficial infections to open mediastinitis with invasion of the sternum, heart, and great vessels . Staphylococcus species are responsible for the majority of sternal infections, but environmental sources can cause infections by other organisms . The common signs and symptoms of mediastinitis are fever, leukocytosis, sternal instability, drainage, and pain . Several risk factors exist for sternal wound infection, with bilateral internal mammary artery bypass grafting in diabetic patients being the most common . Treatment entails surgical debridement with either closed irrigation, open-wound packing, or muscle or omental flap procedures, as well as antibiotic therapy . Some simple procedures help limit the development of sternal infections in certain patients.

Cell Immunol, 1993 Aug, 150(1), 194 - 204
Inhibition of human T cell response to staphylococcal enterotoxin B by prior ligation of surface CD4 molecules; Fournel S et al.; The mechanisms whereby anti-CD4 monoclonal antibodies can block human peripheral blood lymphocyte response to staphylococcal enterotoxin B (SEB) were investigated . Preincubation of peripheral blood mononuclear cells (PBMC) with anti-CD4 mAbs resulted in a profound inhibition of SEB-induced DNA synthesis, while simultaneous addition of antibody and superantigen did not reproducibly decrease the proliferative response . Inhibition was achieved at a very low antibody concentration (0.1 microgram/ml) . It was not increased by cross-linking of anti-CD4 mAb nor mediated by Fc-dependent signals as F(ab')2 antibody fragments were as effective as intact antibodies . Inhibition of proliferation was associated with a profound diminution of IL-2 and IFN-gamma secretion, CD25 (the alpha chain of IL-2 receptor) expression, and blast transformation . Stimulation by SEB after prior ligation of surface CD4 proteins by antibodies was associated with an increased percentage of lymphocytes with chromatin condensation and nuclear fragmentation . It was concluded that stimulation of mature peripheral T cells by SEB through T cell receptors induces an apoptotic signal providing that a small proportion of surface CD4 molecules has interacted with antibodies or F(ab')2 fragments before stimulation by SEB, while simultaneous addition of SEB and anti-CD4 mAb does not prevent the development of a complete activation program in this system . Possible implications of these observations regarding selective clonal deletion of autoreactive T cells by administration of anti-CD4 mAbs in patients with auto-immune diseases are discussed.

Arch Fr Pediatr, 1993 Aug-Sep, 50(7), 609 - 11
{Mycotic aneurysm of the iliac artery disclosed by an abdominal mass}; Bardi I et al.; BACKGROUND . Mycotic aneurysms are classic complications of infective endocarditis . Their diagnosis can be difficult when they are located in deep vessels . CASE REPORT . A 8 year-old boy was admitted for psoitis, tenderness of the left iliac fossa and a palpable mass . He was treated with antibiotics for 2 months for infective endocarditis, but vomiting and fever began after 3 weeks of therapy . Blood cultures showed Staphylococcus epidermidis . Ultrasonography of the mass showed findings compatible with an abscess but sampling of its contents showed blood . Immediate Doppler echography showed that the mass was an aneurysm of the left iliac artery . This diagnosis was confirmed by CT scan and aortography . The aneurysm was excised and a satisfactory repair was made using a Gore-tex graft . CONCLUSION . Although this mass had no clinical vascular characteristics, its origin should have been recognized because of the history of infective endocarditis and a better analysis of the ultrasonographic findings.

Immunology, 1993 Aug, 79(4), 520 - 7
Immunopharmacology of the superantigen staphylococcal enterotoxin A in T-cell receptor V beta 3 transgenic mice; Dohlsten M et al.; The response of mouse T cells to the superantigen staphylococcal enterotoxin A (SEA) requires 1000-fold higher concentrations compared to human T cells . In order to develop a sensitive model for SEA studies in mice, the immunopharmacology has been studied in T-cell receptor (TcR) V beta 3 transgenic (TGV beta 3) and non-transgenic (non-TG) C57Bl/6 mice . The frequency of SEA-responsive T cells in the TGV beta 3 mice exceeded 90%, whereas a 10-fold lower frequency was seen in normal C57Bl/6 mice . Nanograms of SEA injected intravenously into TGV beta 3 mice induced strong cytolytic T lymphocyte (CTL) activity against SEA-coated major histocompatibility complex (MHC) class II+ B-lymphoma cells, whereas administration of 1000-fold higher amounts of SEA to non-TG littermates or normal C57Bl/6 mice induced only a moderate response . Kinetic analysis demonstrated that the CTL activity was more rapidly detectable in TG mice, but substantial levels were seen 2 days after SEA injection in both TGV beta 3 and non-TG mice . The cytotoxic T-cell response induced by SEA in TGV beta 3 and non-TG mice was completely MHC class II dependent, as SEA-coated MHC class II-transfected syngeneic B16 melanoma cells but not untransfected B16 cells were sensitive to lysis . Large amounts of tumour necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) accumulated in serum of TGV beta 3 mice after injection of 10 ng SEA, whereas only marginal amounts were recorded in non-TG even after injection of 100 micrograms SEA . Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis demonstrated that SEA-induced TNF-alpha and IFN-gamma mRNA reached maximal levels 1 hr after SEA administration in TGV beta 3 mice, whereas peak serum levels of TNF-alpha and IFN-gamma proteins were recorded after 2 hr . Comparison of the mRNA levels of a panel of cytokines in the TGV beta 3 and non-TG mice revealed that almost similar amounts of interleukin-1 (IL-1) were induced in both strains, whereas IL-4 was only detected at significant levels in the TGV beta 3 mouse . The results suggest that TGV beta 3 mice are suitable for studying in vivo immune responses to superantigens at concentrations comparable to the potent effects elicited in humans . Moreover, this model is useful for detailed studies on the dynamic regulation of T-cell activation and anergy induced by superantigens.

Biochemistry, 1993 Jul 27, 32(29), 7479 - 87
Mechanism of the reaction catalyzed by staphylococcal nuclease: identification of the rate-determining step; Hale SP et al.; The hydrolysis of single-stranded DNA catalyzed by wild-type staphylococcal nuclease (SNase) and two mutants has been studied as a function of both pH and solvent viscosity . The kcat for wild-type SNase increases with pH; the slope of the plot of log kcat vs pH = 0.45 +/- 0.01 . The dependence of kcat/Km on pH for wild-type SNase is biphasic with a break at pH approximately 8: for pH < or = 8, the plot of log kcat vs pH is linear with a slope = 1.20 +/- 0.06; for pH > or = 8, the slope = 0.00 +/- 0.04 . The dependencies of both kcat and kcat/Km on solvent viscosity are also pH-dependent: below pH 7.3, both kinetic parameters are independent of solvent viscosity; above pH 7.3, both are inversely proportional to solvent viscosity . Thus, at pH 9.5, where SNase is routinely assayed, the rate-determining steps for both kcat and kcat/Km are external steps (product dissociation for kcat and substrate binding for kcat/Km) and not an internal step (e.g., hydrolysis of the phosphodiester bond) . We have also studied the E43D mutant in which the putative active-site general basic catalyst Glu-43 is replaced with Asp . From pH 7.5 to pH 9.5, both log kcat and log (kcat/Km) are directly proportional to pH (slopes = 1.01 +/- 0.03 and 0.95 +/- 0.04, respectively) and independent of solvent viscosity . At pH 9.5, the rate-determining step is an internal step.(ABSTRACT TRUNCATED AT 250 WORDS)

J Immunol, 1993 Jul 15, 151(2), 649 - 57
T-cell presentation of antigen requires cell-to-cell contact for proliferation and anergy induction . Differential MHC requirements for superantigen and autoantigen; LaSalle JM et al.; MHC class II+ human T-cell clones are able to simultaneously present and respond to peptide Ag and superantigen resulting in both proliferation and subsequent anergy . A major question remains as to whether a single T cell can present to itself or whether T-T cell interactions are required . We have employed a novel technique for inhibiting cell-to-cell contact that encapsulates individual T cells in agarose gel microdrops . Myelin basic protein-reactive individual CD4+ T-cell clones entrapped within these microdrops neither proliferated nor became anergized to either peptide Ag or Staphylococcal enterotoxin B (SEB), suggesting that cell-to-cell contact was required for T-cell presentation of Ag leading to proliferation and anergy . PMA treatment induced T-cell migration out of gel microdrops, restoring cell-to-cell contact and resulting in proliferation and anergy after T-cell coculture with peptide or superantigen . However, analysis of {Ca+2}i release revealed differences in T-cell responses to SEB versus peptide Ag . The addition of SEB, but not peptide Ag, induced a calcium flux in solitary T cells . Additionally, alpha HLA-DR mAb blocked peptide but not SEB-induced proliferation and anergy induction . Thus, SEB generated an early signal in solitary T cells that may not be a result of self stimulation via MHC class II . However, subsequent cell-to-cell contact was required for proliferation and anergy induction by SEB . These results indicate that peptide Ag requires a MHC class II-dependent cell-to-cell interaction for calcium flux, proliferation, and anergy induction, whereas SEB requires a MHC class II independent cell-to-cell interaction for proliferation and anergy induction after a TCR-generated calcium flux.

J Immunol, 1993 Jul 15, 151(2), 597 - 609
Functionally anergic lpr and gld B220+ T cell receptor (TCR)-alpha/beta+ double-negative T cells express CD28 and respond to costimulation with phorbol myristate acetate and antibodies to CD28 and the TCR; Giese T et al.; Mice homozygous for lpr and gld develop lymphadenopathy characterized by the progressive accumulation of an unusual population of CD4-, CD8-, CD2-, IL-2R- double-negative (DN) T cells that express reduced levels of TCR-alpha/beta, high levels of CD45 (B220) and Ly-6C and variable levels of CD69 . These cells are refractory to most stimuli, including staphylococcal entertoxins and cross-linking of the TCR, Ly-6C, and CD69 . For normal T cells, the binding of ligand to the TCR alone is insufficient to induce a proliferative response and can result in the induction of a state of prolonged anergy . Efficient stimulation is dependent on the delivery of a second or costimulatory signal . Recently it was reported that CD28 can provide costimulatory signals to T cells and, that these signals can prevent anergy induction in T cell clones . We investigated the possibility that lpr and gld DN T cells are unresponsive because they fail to transduce signals via CD28 . These studies showed that highly purified B220+ TCR-alpha/beta+ DN T cells expressed high levels of CD28, responded weakly to stimulation with PMA and anti-CD28 mAb and quite strongly to PMA, anti-CD28 antibody and high concentrations of immobilized anti-TCR-alpha/beta antibodies . The latter stimulus also induced low levels of expression of CD2 and IL-2R and secretion of modest amounts of IL-2 . Although DN T cells proliferated and secreted IL-2, these responses differed qualitatively and quantitatively from those of +/+ and lprB220- T cells . Consistent with its effects on normal T cells, cyclosporin A partially inhibited the response of DN T cells to TCR cross-linking and CD28 ligation . Studies of synergism between CD28-, Ly-6C-, and CD69-mediated signals revealed that ligation of CD28 enhanced the proliferative response induced by cross-linking of Ly-6C or CD69 on +/+, lpr and gld B220- T cells but had no effect on the unresponsiveness of DN T cells to these stimuli . Ligation of CD28 did not reverse the unresponsiveness of DN T cells to SEB and had only a weak synergistic effect on the response of B220- T cells . Together, these observations suggest that the mechanisms leading to immunosuppression of DN T cells are complex and appear to involve abnormalities in signal transduction via the TCR and CD28 and possibly via Ly-6C and CD69 as well.

Nature, 1993 Jul 8, 364(6433), 152 - 4
Bacterial and retroviral superantigens share a common binding region on class II MHC antigens; Torres BA et al.; Staphylococcal enterotoxin A (SEA), one of the most potent T-cell mitogens known, has been classified as a bacterial superantigen on the basis of ability to stimulate V beta-specific T-cell subsets . SEA interacts with class II major histocompatibility complex (MHC) antigens on antigen-presenting cells and the T-cell antigen receptor (TCR) on T cells, resulting in a ternary complex of MHC-SEA-TCR . Mls antigens are known to be products of mouse mammary tumour virus (MMTV), and it has been reported that two exogenous strains of MMTV encode retroviral superantigens in the open reading frames of the 3' long terminal repeat of the viral genome; however, no binding of the putative MMTV superantigen to either MHC antigens or TCR has been demonstrated . Here we use synthetic peptides to identify a site on the MMTV-1 superantigen that binds to class II MHC antigens . The site is encompassed by amino-acid residues 76-119 of the MMTV-1 superantigen . Direct binding and competition experiments show that the MMTV superantigen and SEA bind to at least one common region on class II MHC antigens.

Infect Immun, 1993 Jul, 61(7), 2995 - 3002
Bovine polymorphonuclear leukocyte killing of Tritrichomonas foetus; Aydintug MK et al.; The role of bovine antibody and complement in bovine neutrophil-mediated killing of Tritrichomonas foetus was investigated . No neutrophil-mediated trichomonacidal activity was detected when Hanks' balanced salt solution, a widely utilized and weakly buffered medium, was used . This lack of neutrophil activity was evident even in the presence of specific bovine antibody and bovine complement . Moreover, the pH of the weakly buffered Hanks' balanced salt solution was observed to fall from pH 7.0 to 5.8 in 4 h at 37 degrees C in the presence of T . foetus . The pH of 5.8 inhibited the bactericidal activity of bovine neutrophils for Staphylococcus epidermidis by 53.2% and may have contributed to the lack of neutrophil-mediated trichomonacidal activity in the weakly buffered salt solution . However, T . foetus was susceptible to bovine neutrophil-mediated destruction when a HEPES (N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid)-buffered Hanks' balanced salt solution was used (21.8% killing by neutrophils alone) . Neither specific bovine immune serum nor purified immune bovine immunoglobulin G2 alone enhanced bovine neutrophil-mediated killing . When complement-sensitized trichomonads were incubated with bovine neutrophils, killing of T . foetus was observed, a result which represented the additive effects of each treatment . Significant (P < 0.05) killing of trichomonads was observed when antibody- and complement-opsonized trichomonads were exposed to bovine neutrophils (> 70% parasite destruction), an effect which reflected the additive nature of each treatment.

Mol Microbiol, 1993 Jul, 9(1), 31 - 9
Regulation of epidermin biosynthetic genes by EpiQ; Peschel A et al.; We investigated the role of epiQ in the biosynthesis of the lantibiotic epidermin . epiQ was essential for epidermin production . It was shown that EpiQ controls epidermin production by transcriptionally activating the epiA promoter, used for transcription of most of the epidermin biosynthetic genes . Additional copies of epiQ increased epidermin production in the epidermin-producing wild-type strain Staphylococcus epidermidis Tu3298 . The epiA promoter region was characterized by primer extension analysis . Two inverted repeats, putative operator sites for EpiQ binding, are located upstream of the -35 region and one is localized downstream of the -10 region . Crude protein extracts from S . epidermidis Tu3298 and epiQ expressing Escherichia coli cells led to gel mobility shifts of a DNA fragment bearing the inverted repeat which is located immediately upstream of the -35 region . DNA fragments bearing the other two inverted repeats were not shifted . The epiQ gene product could be detected by overexpression in the E . coli T7 system using antiserum raised against synthetic peptides of EpiQ . Furthermore, EpiQ, like other DNA-binding proteins, was shown to bind strongly to heparin sepharose.

Biull Eksp Biol Med, 1993 Jul, 116(7), 44 - 5
{Catecholamines in salivary gland and oral mucosal tissue and in the saliva in acute inflammation of the oral soft tissues}; Mikhailov VV et al.; Catecholamine contents in non-stimulated and pilocarpine-stimulated submaxillary salivary gland tissue (SGT), oral mucosa (OM) and stimulated saliva in acute staphylococcal inflammation of soft oral cavity tissue were determined in rats using the standard HPLC method . It was shown that 2 hrs after toxin injection NA contents decreased in non-stimulated SGT . After 24 hrs A contents decreased too as well as HA contents in OM . After 2 and 24 hrs HA contents increased in stimulated SGT, in OM HA contents did not change but A contents after 24 hrs decreased . In saliva, after 24 hrs these levers were normalized . The authors concluded that the inflammatory process in the soft oral cavity tissue was the cause of basal and stimulated salivary secretion disturbance.

Biull Eksp Biol Med, 1993 Jul, 116(7), 38 - 40
{The interrelationship of the content of catecholamines in salivary gland tissue, oral mucosa and in the saliva in experimental staphylococcal sialoadenitis}; Mikhailov VV et al.; Catecholamine contents in non-stimulated and pilocarpine-stimulated submaxillary salivary gland tissue (SGT), oral mucosa (OM) and stimulated saliva in acute experimental staphylococcal sialoadenitis were determined in rats using standard HPLC method . It was shown that 2 hrs after toxin injection, NA contents decreased in non-stimulated SGT, NA and A contents in SGT and OM also decreased . After 2 and 24 hrs NA and A contents were not changed in stimulated SGT and OM and after 24 hrs A content increased in SGT and OM . In saliva after 2 hrs the content and secretion of NA increased, after 24 hrs the content and secretion of NA decreased, but that of A increased . It was concluded that in sialoadenitis the disorders of catecholamine contents in the saliva correlated with its content in OM and influenced the trophic of OM and could be conductive to the development of its pathology.

Biomaterials, 1993 Jul, 14(8), 609 - 14
Altered oxidative responses and antibacterial activity of adult rabbit alveolar macrophages exposed to poly(methyl methacrylate); Giridhar G et al.; The effect of poly(methyl methacrylate) (PMMA) on the oxidative responses and antibacterial activity of adult rabbit alveolar macrophages (AM) was studied . PMMA beads (ca . 0.3 micron diameter) elicited an acute respiratory burst within 6-8 min after the addition of the beads . In contrast . Teflon beads of comparable size (ca . 0.2 micron diameter) did not elicit an oxidative burst of AM . An oxidative response was elicited only by those PMMA samples that had affinity for AM adherence . Incubation of AM with PMMA beads reduced the subsequent phorbol myristate acetate (PMA)-elicited oxidative burst by more than 80% . The Staphylococcus epidermidis--RP12 killing capacity of AM was greatly increased when PMMA beads (ca . 0.3 micron) were added to the challenge dose of bacteria . Pre-incubation of freshly harvested AM with PMMA beads, which greatly reduced subsequent PMA-elicited chemiluminescent (CL) responses did not significantly affect the RP12 killing capacity of AM . Our data also suggest that killing of the RP12 strain of S . epidermidis does not involve reactive oxygen intermediates.

Jpn J Antibiot, 1993 Jul, 46(7), 539 - 46
{Clinical studies on flomoxef in neonates}; Tabuki K et al.; Clinical studies on flomoxef (FMOX) were performed in neonates and the results obtained are summarized as follows . Treatment with FMOX was made in 4 cases of neonatal bacterial infections; 2 cases of sepsis (suspected) and 1 case each of infection of umbilicus and staphylococcal scalded skin syndrome . Results obtained were excellent in 1 case, good in 3 cases . No significant side effects due to the drug were observed in any cases.

Int Immunol, 1993 Jul, 5(7), 717 - 24
Stimulation of murine intestinal intraepithelial lymphocytes by the bacterial superantigen staphylococcal enterotoxin B; Siebrecht MS et al.; To gain insight into the specificity and function of intestinal intraepithelial lymphocytes (IEL), we have examined their response to staphylococcal enterotoxin B (SEB), a significant cause of food poisoning and a potent T cell mitogen . IEL include two populations of TCR alpha beta+ T cells . One of these resembles the T cells found in the Peyer's patch and is thymus dependent . The other subset is characterized by both TCR alpha beta and gamma delta+ IEL bearing a unique form of the CD8 molecule, expressed as an alpha alpha homodimer . CD8 alpha+ beta- IEL are thymus independent and appear to mature extrathymically in the gut epithelium . Two-color flow cytometric analysis showed that in vitro stimulation of IEL with SEB resulted in the expansion of the thymus dependent but not the thymus independent IEL; the CD8 alpha+ beta- IEL were functionally non-responsive to stimulation with SEB . 'Forbidden' self-superantigen reactive T cells present among IEL were also non-responsive to stimulation with SEB . The presence or absence of class II MHC molecules does not appear to play a role in the non-responsiveness to SEB, since CD8 alpha+ beta- IEL from class II deficient mice also failed to respond to stimulation with SEB . Depletion of CD8 beta+ and CD4+ T cells from total IEL decreased IL-2 production by IEL in response to cross-linking with anti-CD3, suggesting that the non-responsiveness of CD8 alpha+ beta- IEL extends to antigens other than SEB.

Dermatol Clin, 1993 Jul, 11(3), 597 - 609
Bullous dermatoses associated with systemic disease; Feldman SR; The bullous diseases that are neither immune-mediated nor inherited form a heterogeneous group that may be classified according to their major histopathologic characteristics . Such a classification allows clear distinctions to be made between entities that may have clinical similarities such as staphylococcal scalded skin syndrome, toxic shock syndrome, erythema multiforme/toxic epidermal necrolysis, and acute graft-versus-host disease . Proper differentiation of these entities is critical for their study and for appropriate management.

Protein Sci, 1993 Jul, 2(7), 1155 - 60
Characterization of the stable, acid-induced, molten globule-like state of staphylococcal nuclease; Fink AL et al.; Titration of a salt-free solution of native staphylococcal nuclease by HCl leads to an unfolding transition in the vicinity of pH 4, as determined by near- and far-UV circular dichroism . At pH 2-3, the protein is substantially unfolded . The addition of further HCl results in a second transition, this one to a more structured species (the A state) with the properties of an expanded molten globule, namely substantial secondary structure, little or no tertiary structure, relatively compact size as determined by hydrodynamic radius, and the ability to bind the hydrophobic dye 1-anilino-8-naphthalene sulfonic acid . The addition of anions, in the form of neutral salts, to the acid-unfolded state at pH 2 also causes a transition leading to the A state . Fourier transform infrared analysis of the amide I band was used to compare the amount and type of secondary structure in the native and A states . A significant decrease in alpha-helix structure, with a corresponding increase in beta or extended structure, was observed in the A state, compared to the native state . A model to account for such compact denatured states is proposed.

Appl Environ Microbiol, 1993 Jul, 59(7), 2210 - 3
Simple solutions to false-positive staphylococcal enterotoxin assays with seafood tested with an enzyme-linked immunosorbent assay kit (TECRA); Park CE et al.; The TECRA kit, a commercial staphylococcal enterotoxin visual immunoassay kit, is an enzyme-linked immunosorbent assay system which utilizes polyvalent antisera against staphylococcal enterotoxin types A to E . The test is simple and rapid to perform (4 h) and has therefore been widely used for screening purposes . In this study, the TECRA kit produced a number of false-positive reactions with seafood; 25% of 218 samples of seven types of seafood gave false-positive results, particularly shellfish such as mussels (85%), clams (32%), oysters (23%), winkles (20%), and squid (13%) . Some nonshellfish samples also gave false-positive results with the TECRA kit (smelt {20%} and trout {10%}) . The substance contributing to the false-positive results differed from true staphylococcal enterotoxins in that it was: (i) heat labile, being completely inactivated by heating for 3 min at 70 degrees C, compared with 5% inactivation of true staphylococcal enterotoxins by the same heat treatment, (ii) in a selective reaction with normal rabbit or calf serum (nonspecific reactions were completely abolished by these sera, whereas staphylococcal enterotoxins were not affected), and (iii) incapable of binding to a copper-chelate Sepharose gel (all of the substance remained in the unbound wash fraction, whereas staphylococcal enterotoxins were quantitatively bound to the gel) . The false-positive reactions occurring with seafood were not associated with substances produced by microorganisms, since the bacterial isolates from the samples did not give positive results with the TECRA kit.(ABSTRACT TRUNCATED AT 250 WORDS)

Clin Infect Dis, 1993 Jul, 17(1), 46 - 55
Sustained bacteremia in 26 patients with a permanent endocardial pacemaker: assessment of wire removal; Camus C et al.; We reviewed the data on 26 patients with permanent endocardial pacemakers who had 28 episodes of bacteremia to determine whether removal of the wire is required . Patients recovered completely from the first episode in seven of 20 cases of staphylococcal bacteremia and in six of six cases of nonstaphylococcal bacteremia (P = .015) . Definitive cure was not achieved during the first episode in seven cases of staphylococcal bacteremia related to the pacing system when the wire was not withdrawn; however, cure was achieved in five of six cases when the whole pacemaker was removed (P < .01) . The duration of treatment was longer for the patients from whom the wire was not removed during the first episode (P < .01) . Whether cases of staphylococcal bacteremia were related to the pacing system or not, the rate of recovery of the responsible microorganism from the wires was similar for both groups of patients (six {82%} of seven and three {75%} of four, respectively) . Nonstaphylococcal bacteremia was unrelated to the pacing system in five of six cases; these patients were all cured without removal of the wire.

Mol Immunol, 1993 Jul, 30(10), 877 - 86
An alternative method for T-cell receptor repertoire analysis: clustering of human V-beta subfamilies selected in responses to staphylococcal enterotoxins B and E; Champagne E et al.; We have designed a convenient procedure for the analysis of V beta repertoire expression in polyclonal T-cell populations . In this procedure T-cell RNA is converted to cDNA, polydC-tailed with terminal deoxynucleotidyl transferase and submitted to one-side specificity PCR amplification with a constant region oligonucleotide primer . The amplified material is then analysed by reverse spot-test hybridization: after 32P-labelling, the amplification product is put to hybridize on a membrane where specially designed V beta subfamily-specific probes are immobilized . The radioactivity fixed on each probe can then be easily quantified and the signal obtained is directly proportional to the initial amount of homologous RNA . We applied this technique to the study of V beta gene selection following T-cell stimulation by staphylococcal enterotoxins B and E . We show that with these toxins two almost non-overlapping sets of T-cells are recruited and that this selection is likely to be dependent on specific amino acid residues shaping the fourth complementarity determining region of the TCR-beta chain . These residues constitute two tandemly-conserved tripeptide sequences (Asp39Pro40Gly41)-(Val69Ser70Arg71) and (Arg66Phe67Ser68)-(Asp88Ser89Ala90) in the SEB- and the SEE-responsive V beta gene clusters respectively.

Scand J Immunol, 1993 Jul, 38(1), 89 - 94
Reactivity of human gamma delta T cells to staphylococcal enterotoxins: a restricted reaction pattern mediated by two distinct recognition pathways; Rust C et al.; Staphylococcal enterotoxins (SEs) are known superantigens for T cells expressing the alpha beta T-cell receptor (TCR) . They bind to MHC class II molecules on antigen-presenting cells and can subsequently trigger T-cell responses by binding to V beta-gene products . The reactivity of gamma delta T cells with enterotoxins is less well defined although both proliferative and cytotoxic responses have been described . In the present study we have tested the cytotoxic reactivity of a panel of 41 gamma delta T-cell clones against target cells coated with the enterotoxins SEA, SEB, SEC1, SEC2, SEC3, SED, SEE or TSST . Three reaction patterns were observed with the gamma delta T-cell clones: (1) clones that specifically lysed SEA-coated target cells only; (2) clones that specifically lysed SEE-coated target cells only, and (3) clones that specifically lysed SEA-coated target cells only in the presence of certain human sera . The presence of SEA-specific antibodies in such human sera could be demonstrated . Moreover, gamma delta T-cell clones of this third category expressed the IgG FcRIII (CD16) which indicates that these clones are capable of mediating antibody-dependent cellular cytotoxicity towards SEA-coated target cells . Thus, the cytotoxic response of gamma delta T cells to SEs is mediated by two distinct pathways: an antibody-independent and an antibody-dependent pathway . The antibody-independent reactivity of gamma delta T cells was directed to either SEA or SEE, whereas antibody-dependent reactivity was found only towards SEA . The capacity of gamma delta T-cell clones to respond to stimulation with SEs, combined with their high cytolytic capacity in vitro, suggests that these cells can be involved in SE-directed immune responses and efficiently kill SE-coated target cells in vivo.

Chest, 1993 Jul, 104(1), 88 - 93
Perivalvular abscesses associated with endocarditis . Clinical features and diagnostic accuracy of two-dimensional echocardiography; Aguado JM et al.; OBJECTIVE: To determine the clinical implications of the development of a perivalvular abscess in the course of an infective endocarditis and evaluate the utility of two-dimensional echocardiography in the diagnosis of this complication . DESIGN: Retrospective clinical review . Investigator-blinded comparative echographic case-control study . SETTING: Tertiary referral center . PATIENTS: Forty patients with infective endocarditis and a histologically proved diagnosis of perivalvular abscess . INTERVENTION: Two-dimensional echocardiograms corresponding to 36 of these 40 patients were blindly compared with two-dimensional echocardiograms of 20 randomly chosen patients with infective endocarditis in whom myocardial abscesses had not been demonstrated during surgery . MEASUREMENTS AND MAIN RESULTS: During surgery or at autopsy, 40 patients had a total of 41 definite perivalvular abscesses . Native valve endocarditis was present in 27 patients, and prosthetic valve endocarditis was present in 13 patients . Abscesses were more frequent in aortic-valve endocarditis (57.5 percent) than in infections of other valves, and the infecting organism was more often Staphylococcus (42.5 percent of cases) . The hospital mortality rate was 90 percent in the 10 patients who did not receive surgical treatment, as compared with 26.6 percent in the 30 operated-on patient (p < 0.001) . Sensitivity and specificity for the detection of abscesses associated with endocarditis were 80.5 percent and 85 percent, respectively, for transthoracic two-dimensional echocardiography . CONCLUSIONS: Our data indicate that transthoracic echocardiography remains an accurate method for the diagnosis of abscesses associated with endocarditis, even in the presence of a prosthetic valve, and it could help to indicate early surgery in these patients.

J Exp Med, 1993 Jul 1, 178(1), 331 - 6
The structural basis of germline-encoded VH3 immunoglobulin binding to staphylococcal protein A; Hillson JL et al.; The ability of human VH3 immunoglobulins (Ig) to bind to staphylococcal protein A (SPA) via their Fab region is analogous to the binding of bacterial superantigens to T cell receptors . The present report establishes the structural basis for the interaction of SPA and VH3 Ig . We have studied a panel of 27 human monoclonal IgM that were derived from fetal B lymphocytes . As such, these IgM were expected to be encoded by unmutated germline genes . Binding to SPA in ELISA occurred with 15 of 15 VH3 IgM, but none of 12 IgM from the VH1, VH4, VH5, or VH6 families . The VH sequences of the 27 IgM were derived from 20 distinct VH elements, including 11 from the VH3 family . Use of D, JH, and CL genes was similar among VH3 and non-VH3 IgM . A comparison of the corresponding VH protein sequences, and those of previously studied IgM, identified a probable site for SPA binding that includes VH3 residues in framework region 3 (FR3), and perhaps FR1 and 3' complementary determining region 2 . The results thus demonstrate that among human IgM, specificity for SPA is encoded by at least 11 different VH3 germline genes . Furthermore, like the T cell superantigens, SPA likely binds to residues in the VH framework region, outside the classical antigen-binding site of the hypervariable loops.

J Pediatr Surg, 1993 Jul, 28(7), 894 - 7
Central line perforation associated with Staphylococcus epidermidis infection; Bansal V et al.; We present detailed case reviews of four very low birth weight (VLBW) infants in whom central venous silastic catheter perforation was associated with Staphylococcus epidermidis sepsis . The diagnostic and therapeutic dilemma presented by the intracavitary fluid collections occurring in all four of these cases proved to be of clinical interest . Additionally, we propose a model that may account for the etiology of catheter displacement--localized phlebitis as a result of S epidermidis infection with resultant extralumenal migration of the central venous catheter.

Indian J Exp Biol, 1993 Jul, 31(7), 653 - 4
New microbiological method for the detection of staphylococcal beta-lactamase; Bhat KG et al.; The method has been designed as such to include the induction and testing of beta-lactamase in a single procedure . This method compares favourably with the existing method.

Immunobiology, 1993 Jul, 188(3), 293 - 302
Cytokine production of the human monocytic cell line Mono Mac 6 in comparison to mature monocytes in peripheral blood mononuclear cells; Neustock P et al.; Mono Mac 6 is a human monocytic cell line with several features of mature blood monocytes such as CD 14 antigen expression, phagocytotic ability, and the functional ability to produce cytokines . This line is often used as an in vitro model to demonstrate the actions of monocytes . In our study, the production of cytokines by Mono Mac 6 cells in response to various stimulants was analyzed and compared to that of mature monocytes in peripheral blood mononuclear cells (PBMC) . Interestingly, the Mono Mac 6 cells produced IL-1 alpha/beta, IL-6, and TNF-alpha after induction with the lectin phytohaemagglutinin A (PHA), mainly known as a T cell activator . The amount of cytokine release did not decrease in the presence of polymyxin B (Pmb), an inhibitor of LPS-induced effects . Kinetic studies revealed maximum cytokine levels 24h after stimulation, whereas human PBMC produced higher yields of all cytokines and enhancement was observed up to 48 hours after induction . Stimulation with the superantigen derived from the supernatant of mycoplasma arthritidis (MAS) induced expression of IL-1 beta, IL-6, and TNF-alpha, whereas staphylococcus enterotoxin B (SEB) did not induce any cytokine release . Further experiments analyzed the ability of Mono Mac 6 cells to produce IFN-alpha which is an important characteristic of mature monocytes . The cells were induced either with inactivated Newcastle Disease Virus (NDV), Sendai Virus, or the synthetic stimulus poly I:C IFN-alpha expression was not detected on the transcriptional or the protein level . In addition, no co-expression of IL-1 and IL-6 was observed in response to these stimuli . Since NDV, Sendai Virus, and poly I:C represent strong IFN-alpha inducers in peripheral blood monocytes, these data indicate that Mono Mac 6 cells lack the ability to express IFN-alpha . In conclusion, our findings show that this cell line is a potent cytokine producer, but the capacity to produce IFN is apparently deficient.

Gig Sanit, 1993 Jul, (7), 44 - 7
{Staphylococcus carriers in workers of the Astrakhan gas condensing plant}; Bukharin OV et al.; Frequency of staphylococcus carriership in upper respiratory route mucosa of workers engaged in gas industry depends on intensity and duration of occupational contact with chemical pollutants of the working environment.

Eur J Immunol, 1993 Jul, 23(7), 1513 - 22
Activation with superantigens induces programmed death in antigen-primed CD4+ class II+ major histocompatibility complex T lymphocytes via a CD11a/CD18-dependent mechanism; Damle NK et al.; Staphylococcal enterotoxin superantigens (SAg) bind class II major histocompatibility complex (MHC) molecules on antigen-presenting cells (APC) and upon cell-to-cell contact stimulate proliferation of T cells expressing appropriate V beta gene products . In addition, SAg can also deliver negative signals to Ag-specific T cells resulting in a state of unresponsiveness or a loss of viability . The present study examines the functional consequences of a direct interaction of SAg with alloAg-specific class II MHC+ CD4+ T cell lines (TCL) . Our results demonstrate that SAg induce programmed death (apoptosis) in a majority of Ag-specific CD4+ T cells accompanied by genomic DNA fragmentation . SAg binding to Ag-specific TCL resulted in a rapid mobilization of intracellular free calcium ({Ca2+}i) and transcription of a number of cytokine genes including interleukin-2(IL-2), IL-4, interferon-gamma (IFN-gamma), granulocyte-macrophage colony-stimulating factor (GM-CSF), and granzyme B indicating the activation of primed T cells . Both SAg-induced cytokine gene expression as well as subsequent death were significantly inhibited by a tyrosine kinase inhibitor herbimycin A and also by cyclosporin A . SAg-induced death of primed T cells was also inhibited by monoclonal antibodies (mAb) directed at the CD11a/CD18 molecule but not those reactive with other T cell surface molecules such as CD2, CD7, CD28, CD29 or CD49d . None of these mAb, including anti-CD11a/CD18, had any effect on SAg-induced expression of IL-2 and IL-4 genes or SAg-induced {Ca2+}i response . Addition of cytokines such as IL-1 alpha, IL-2, IL-4, IL-6, GM-CSF, IFN-gamma, tumor necrosis factor (TNF-alpha, or TNF-beta), or neutralizing Ab to these cytokines had no effect on SAg-induced death of Ag-specific TCL . The T cells which survived the death-inducing effects of SAg showed down-regulation of the CD3/T cell receptor and up-regulation of CD2 and HLA-DR expression, and upon re-exposure to the same SAg upregulated expression of mRNA for IL-2 and IFN-gamma . Presentation of SAg by B7+ ICAM-1+ LFA-3+ DR+ professional APC was also able to induce the death of Ag-specific TCL . Together these results suggest that the activation with SAg causes programmed death of Ag-specific TCL cells via a mechanism that requires late participation of the CD11a/CD18 molecule.

J Bone Joint Surg Br, 1993 Jul, 75(4), 562 - 5
Open adult femoral shaft fracture treated by early intramedullary nailing; Grosse A et al.; In two hospitals, 115 consecutive open femoral shaft fractures were treated by meticulous wound excision and early locked (97) or unlocked (18) intramedullary nailing . All the fractures united; union was delayed in four, three of which required bone grafting . The average range of knee flexion at follow-up was 134 degrees (60 to 148) . Five patients had a final range of less than 120 degrees, but three of these improved after manipulation under general anaesthesia . Three patients developed staphylococcal infections and required further surgical treatment . All eventually healed.

Zh Mikrobiol Epidemiol Immunobiol, 1993 Jul-Aug, (4), 25 - 30
{The diagnosis of staphylococcal infection by the determination of antigen-binding lymphocytes}; Deriabin PN et al.; Examination of 255 patients with different pyo-inflammatory and septic diseases revealed high effectiveness of the detection of staphylococcal infection by the determination of antigen-binding lymphocytes (ABL) in the indirect rosette-formation test with the use of specially designed staphylococcal erythrocytes immune reagents . ABL were detected in 63% of the examined patients, their content varied between 0.57% and 6.41% (which was, on the average, equal to 1.92 +/- 0.10%) . The effectiveness of the method depended on the specificity of the staphylococcal reagent used in the test and on the time of examination of the patients . In patients with acute processes the determination of ABL permitted the diagnosis of staphylococcal infection before the activity of the corresponding serum antibodies could be measured . ABL were classified with T, B and "zero" populations of lymphocytes.

Klin Lab Diagn, 1993 Jul-Aug, (4), 22 - 5
{Prognostic significance of the NBT test in patients with ichterohaemorrhagic leptospirosis}; Avdeeva MG et al.; The values of spontaneous NBT test significantly rise at the peak of leptospirosis in patients with an uncomplicated course of the disease (p < 0.05) . Low values of the spontaneous NBT test with stimulation with Staphylococcus in patients with grave leptospirosis predict the development of life-threatening complications . Leptospirosis vaccine reduced the elevated values of the NBT in leptospirosis . The depressing effect of leptospirosis vaccine is indicative of a high risk of development of late complications.

J Clin Immunol, 1993 Jul, 13(4), 247 - 58
Reduced interleukin-2 (IL-2) production in common variable immunodeficiency is due to a primary abnormality of CD4+ T cell differentiation; Eisenstein EM et al.; Common variable immunodeficiency (CVI) is a condition characterized by hypogammaglobulinemia and impaired antibody responses, resulting in recurrent bacterial infections in untreated patients . In addition, affected individuals exhibit an increased incidence of autoimmunity, malignancy, and certain viral infections, suggesting the presence of an underlying generalized immune dysregulation . We have previously described a subgroup of CVI patients in whom T cells within PBMC populations exhibit a selective defect in lymphokine production . IL-2, IL-4, and IL-5 mRNA production was impaired in these patients, while proliferation, IL-2R expression, and c-myc mRNA production were normal . In the present series of experiments, using highly purified CD4+ T cells prepared by negative selection, we show that this lymphokine production defect is a primary abnormality of CVI CD4+ T cells: whereas CD4+ T cells from CVI patients proliferate normally in response to stimulation by PHA, staphylococcal enterotoxin B (SEB), or anti-CD2 antibodies, these stimuli induce significantly less IL-2 production than observed with CD4+ T cells from normal individuals . Furthermore, we show that this IL-2 production defect is not due to an accessory cell abnormality, since it was seen in the presence of normal (allogeneic) accessory cells, and patient accessory cells supported normal amounts of IL-2 production by PHA-stimulated CD4+ T cells obtained from normal individuals . Of interest, we also found that while IL-2 production by CD4+ T cells from CVI patients induced by stimulation with immobilized anti-CD3 antibody was reduced compared to CD4+ T cells from normal control individuals, this reduction was not statistically significant . Furthermore, stimulation of both CVI patient and normal CD4+ T cells with either ionomycin+phorbol myristate acetate or a combination of immobilized anti-CD3 antibody plus anti-CD28 antibody resulted in a 50-fold increase in IL-2 production compared to stimulation with immobilized anti-CD3 antibody alone, and, under these conditions, CVI and normal CD4+ T cells produced equivalent amounts of IL-2 . Finally, minor defects in interferon-gamma production by CD4+ T cells from CVI donors were observed, but these were less severe than the IL-2 production defects and were not statistically significant . We conclude that a primary abnormality of lymphokine production exists in the CD4+ T cells of a subset of patients with CVI.(ABSTRACT TRUNCATED AT 400 WORDS)

Immunol Lett, 1993 Jul, 37(1), 53 - 62
CD4 but not CD8 is comodulated with the T-cell antigen receptor (TCR) after activation of a CD4+ CD8+ human leukemia line with staphylococcal enterotoxin; Bodo I et al.; Recent studies support the possibility of an interaction between CD4/8 and the TCR complex . To determine if there is specificity in this interaction, we have studied the comodulation of CD4/8 with the CD3/TCR complex on a CD4+ CD8+ human leukemic T-cell line stimulated with staphylococcal enterotoxin A (SEA) bound to Raji cells . FACS analysis revealed that CD3 and the TCR were modulated from the surface . CD4 and not CD8 was comodulated with the T-cell receptor complex, supporting the existence of a docking site on the TCR with selectivity for CD4 or CD8 but not both . Fewer than 45 SEA molecules per presenting cell led to detectable comodulation . The ratio of %CD4/%TCR modulation varied with both time and the amount of SEA used for stimulation . ConA or PHA induced modulation of CD3 but, unlike SEA, failed to induce IL-2 secretion, suggesting multiple pathways and states of T-cell activation . Our findings also suggest that some human T leukemic lines can respond to antigen.

Immunobiology, 1993 Jul, 188(3), 259 - 73
Induction of IgE and IgG1 in human B cell cultures with staphylococcal superantigens: role of helper T cell interaction, resistance to interferon-gamma; Armerding D et al.; Non-antigen-specific activation of human B lymphocytes for IgE production in vitro requires the presence of interleukin 4 and non-cognate physical interaction with T cells . The latter can be replaced by antibodies directed against the B cells' CD40 structure . Antigen-specific induction of immunoglobulin responses, including IgE, is difficult in human lymphocyte cultures . Thus, we developed a model system which might resemble physiological B lymphocyte stimulation by antigen . Co-cultures of purified tonsillar B cells from normal donors with non-HLA matched T helper clones obtained from the skin of atopic dermatitis patients produced significant levels of IgE and IgG1 after stimulation with appropriate types of staphylococcal exotoxins, provided that IL-4 was also induced in the T cells . Such responses were further enhanced by addition of low doses of anti-CD40 antibodies . Concentrations of anti-CD40, optimal for stimulation of B cells in the absence of T helper lymphocytes, were less effective in this regard and even inhibitory in some experiments . Most powerful immunoglobulin induction was observed when the cultures were spiked with low amounts of IL-4 and anti-CD40 which did not elicit substantial immunoglobulin production in the absence of the staphylococcal exotoxins . Induction of IL-2 in T/B cell cultures by superantigens without production of appreciable quantities of IL-4 provoked considerable IgG1 titer but no IgE . High amounts of interferon-gamma generated by the T cells in vitro in the presence of superantigens did not appear to interfere with immunoglobulin induction . Addition of recombinant interferon at the beginning of the culture period at doses which effectively suppressed IL-4 plus anti-CD40 induced immunoglobulin responses did not inhibit T helper and superantigen dependent B cell activation . Superantigen mediated B cell stimulation for immunoglobulin production was dependent on cell-cell contact . The experimental results presented suggest that this cellular interaction did not necessarily involve T-B cell bridging by superantigens.

J Neuroimmunol, 1993 Jul, 46(1-2), 5 - 10
Staphylococcal enterotoxin enhances the activation of rat encephalitogenic T cells by myelin basic protein; Sun D; It is generally believed that the activation of autoreactive T cells is an essential step in the pathogenesis of autoimmune diseases; however, autologous antigens are often weak immunogens and their detectable levels in vivo are much lower than required for T-cell activation . In experimental autoimmune encephalomyelitis, encephalitogenic T cells specific for myelin basic protein (MBP) react weakly to autologous rat myelin basic protein (RBP) but strongly to guinea pig-derived basic protein, even though both ligands possess the essential epitope (MBP(68-88)) . Here we demonstrate that RBP is converted to a strong immunogen in the presence of a small dose of bacterial superantigen, staphylococcal enterotoxin E (SEE) . The enhancing effect of SEE on the rat protein was apparent with all encephalitogenic T-cell lines examined in this study, including those not responding to RBP alone . It depended, moreover, on the simultaneous presence of RBP and SEE; delaying the addition of SEE for 8-12 h greatly decreased the potency of RBP . None of a series of major cytokines was able to replace SEE as an enhancer . Our results indicate that two T ligands, one a bacterial superantigen, can interact to enhance the activation of autoreactive T cells . This observation has implications for the involvement of bacterial and viral infections in the pathogenesis of multiple sclerosis.

Cell Immunol, 1993 Jul, 149(2), 268 - 78
Immunomodulation of experimental autoimmune encephalomyelitis by staphylococcal enterotoxin D; Matsumoto Y et al.; Staphylococcal enterotoxins (SEs) can bind major histocompatibility antigens and stimulate T cells which bear particular types of T cell receptor . Therefore, it has been postulated that SEs may trigger or modulate the development of autoimmune diseases caused by T cells . In the present study, we examined the effects of SEs on rat encephalitogenic T cells and the clinical manifestation of experimental autoimmune encephalomyelitis (EAE) . SED, but not other SEs, stimulated encephalitogenic T cells . Furthermore, culture of lymphoid cells from myelin basic protein (MBP)-immunized rats with SED augmented the clinical manifestation of passively transferred EAE, whereas SEA and SEB showed no significant EAE-transfer ability . Flow cytometric analysis demonstrated that in vitro SED stimulation of T cells from MBP-immunized rats, but not from normal rats, resulted in selective expansion of V beta 8.2+ T cells . Consistent with in vitro findings, in vivo administration of SED modulated EAE elicited by immunization with MBP . SED given after the immunization augmented clinical manifestation, especially at low doses . On the other hand, SED given 7 days before the immunization suppressed the development of EAE in a dose-dependent manner . Interestingly, the same toxin given at a dose of 20 micrograms to thymectomized rats induced enhanced EAE regardless of the timing of administration . It has already been established that SEs stimulate T cells bearing a particular type of TCR V beta chain and subsequently induce unresponsiveness of these T cells . The present results suggest that a similar mechanism may operate in rats after the toxin treatment and MBP immunization . However, in vitro assay showed that the proliferative responses of T cells from EAE-suppressed rats to MBP and SED were not eliminated, suggesting that SED-induced suppressor T cells may also play some roles in EAE suppression . The present study has shown that SED, one of the superantigens, modulates an autoimmune disease . More importantly, its effects are not uniform, but instead are closely related to the dose of the toxin, timing of toxin exposure, and the status of hosts.

Biochem Biophys Res Commun, 1993 Jun 30, 193(3), 1191 - 7
Agonist properties of a microbial superantigen peptide; Pontzer CH et al.; Staphylococcal enterotoxin A (SEA) binds to class II major histocompatibility complex (MHC) molecules and stimulates monocytes to produce tumor necrosis factor alpha (TNF alpha) and interleukin one (IL-1) . We have examined the monocyte stimulatory activity of individual synthetic peptides encompassing the entire sequence of the SEA molecule . Only one peptide, SEA(121-149), induced both TNF alpha and IL-1 production at a concentration as low as 30 microM . Consistent with its effects on monocyte function, SEA(121-149) was shown to bind directly to class II MHC molecules on the surface of both monocytes and B cells, and its binding was inhibited specifically by native SEA . Further, polyclonal antibody to SEA(121-149) inhibited induction of TNF alpha by both SEA and toxic shock syndrome toxin one . Thus, we have identified SEA(121-149) as a peptide agonist of SEA monocyte stimulatory activity.

Med Clin (Barc), 1993 Jun 19, 101(4), 138 - 40
{New diagnostic and therapeutic aspects of hyper-IgE syndrome . Report of 3 cases}; Matamoros Flori N et al.; Three female patients, 46, 34, and 19 years old, diagnosed of hyper-IgE syndrome are reported . The most relevant clinical findings are recurrent sinopulmonary tract infections, cold staphylococcal abscesses and chronic dermatitis . All patients presented elevated serum IgE levels (> 3,000 U/ml) and blood eosinophilia (> 0.6 x 10(9) cel/l) . Two patients presented impaired antibody forming capacity to tetanus and pneumococcal antigens; one of these patients also had low serum IgG2 levels . After initiation of the intravenous gammaglobulin therapy, a marked improvement of infectious problems was observed . The controversial pathophysiology of this syndrome, the antibody deficiency present in some patients and the rationale for intravenous gammaglobulin therapy are discussed.

J Immunol, 1993 Jun 15, 150(12), 5604 - 13
Microbial superantigens induce NF-kappa B in the human monocytic cell line THP-1; Trede NS et al.; Staphylococcal superantigens bind to MHC class II molecules and induce transcriptional activation of IL-1 beta and TNF-alpha genes in human monocytic cells . The understanding of the mechanisms by which superantigens activate cytokine gene expression is incomplete . In this study, we demonstrate that toxic shock syndrome toxin-1 (TSST-1) and staphylococcal enterotoxins A and B induce the activation of NF-kappa B, a transcriptional enhancer that binds to sequences found in both the IL-1 beta and TNF-alpha promoters . Electrophoretic mobility-shift assays showed a rapid induction of nuclear proteins that bound to the consensus kappa B motif . Furthermore, TSST-1 potently stimulated chloramphenicol acetyltransferase (CAT) expression by THP-1 cells transfected with a consensus NF-kappa B-promoter CAT construct, indicative of induction of NF-kappa B enhancer function . Induction of both NF-kappa B DNA-binding proteins and NF-kappa B enhancer function was down-regulated by inhibitors of protein kinase C and protein tyrosine kinase, indicating a role for these protein kinases in the induction of NF-kappa B by MHC class II ligands . Using neutralizing antibodies, we demonstrated that after the stimulation of cells with TSST-1, TNF-alpha, but not IL-1 beta, acted to up-regulate binding of NF-kappa B to DNA and the activation of the NF-kappa B-promoter CAT construct . These results indicate that induction of NF-kappa B by superantigens is up-regulated in part by an autocrine loop involving TNF-alpha.

FEMS Microbiol Lett, 1993 Jun 15, 110(2), 205 - 11
Extracellular proteolytic activation of bacteriolytic peptidoglycan hydrolases of Staphylococcus simulans biovar staphylolyticus; Neumann VC et al.; Staphylococcus simulans biovar staphylolyticus secreted two bacteriolytic peptidoglycan hydrolases as proproteins that were activated as they were processed by an extracellular sulphydryl protease . This processing resulted in the production of multiple molecular-mass forms of each enzyme . Cells from early exponential phase cultures were susceptible to lysis by the mature forms of each of the peptidoglycan hydrolases whereas stationary phase cells were resistant . Thus secretion of these bacteriolytic enzymes during early exponential growth as precursors that are activated later by the protease would provide time for the cells to become resistant.

J Biol Chem, 1993 Jun 5, 268(16), 11963 - 7
Altered pore-forming properties of proteolytically nicked staphylococcal alpha-toxin; Palmer M et al.; Staphylococcal alpha-toxin is a single-chain polypeptide with a molecular weight of 34,000 that hexamerizes in lipid bilayers to form pores of 1-1.5 nm effective diameter in membranes . We demonstrate that limited proteolysis of purified alpha-toxin with proteinase K generates a hemolytically active product that yields one major protein band of 17-18 kDa in SDS-polyacrylamide gel electrophoresis . The 17-18-kDa protein band harbors two major fragments of similar size representing the N- and C-terminal halves, which remain associated with each other in non-denaturing buffers but dissociate in 6 M urea . Dissociation in urea leads to loss of hemolytic activity . In contrast, unnicked alpha-toxin is not inactivated by urea . Nicked, hemolytically active alpha-toxin forms hexamers on erythrocyte membranes and on lymphocytes and monocytes . However, the nicked toxin can only lyse erythrocytes and fails to permeabilize nucleated cells . Osmotic protection experiments indicate that the size of pores generated by the nicked toxin is considerably smaller (0.6-0.9 nm effective diameter) than that generated by native toxin . The collective results do not support a previous proposal that different functions of alpha-toxin are contained in separate domains of the molecule.

Arch Biochem Biophys, 1993 Jun, 303(2), 367 - 76
The serine protease inhibitor family from Ascaris suum: chemical determination of the five disulfide bridges; Bernard VD et al.; Chymotrypsin/elastase inhibitor-1 is a member of the Ascaris family of serine protease inhibitors . It is characterized by five disulfide bridges in a polypeptide chain of 63 amino acids . The disulfide bridge pairing was resolved by cleavage at methionyl residues with cyanogen bromide followed by a combination of proteolytic digestions with glycyl endopeptidase, Staphylococcal serine proteinase, and submandibular proteinase A . The peptides were separated on a reverse-phase HPLC column . Amino acid analyses and N-terminal microsequencing of the cystine containing peptides revealed the disulfide bridge pairing between residues 5-54, 15-29, 18-38, 22-33, and 40-60 . The disulfide bridge pairing of other members of this unique family was also assigned . The major isoform, trypsin inhibitor-1, and chymotrypsin/elastase inhibitor-4 share the same disulfide bridge pattern . These results strongly suggest that all members of the Ascaris family of serine protease inhibitors have the same disulfide bridge pattern which represents a unique motif.

J Vasc Surg, 1993 Jun, 17(6), 1077 - 80; discussion 1080-2
Do infected inguinal lymph nodes increase the incidence of postoperative groin wound infection?
Josephs LG, Cordts PR, DiEdwardo CL, LaMorte WW, Menzoian JO.
PURPOSE: Risk factors for postoperative wound infection in patients undergoing vascular surgery may include age, comorbid conditions, wound classification, use of prosthetic grafts, and repeat operations . Groin incisions, in particular, pose substantial risk during placement of prosthetic grafts . METHODS: To investigate the role of infected inguinal lymph nodes (LN) in groin wound infection (GWI), we excised an inguinal LN from 69 consecutive patients (89 groins) undergoing 36 infrainguinal reconstructions, 24 aortobifemoral bypasses, 12 extra-anatomic femoral bypasses, 11 vein stripping, and 6 femoral pseudoaneurysm repairs . LN Gram staining was performed, and aerobic and anaerobic cultures were obtained . In addition cultures were taken from any ulcerated or gangrenous lesion on the ipsilateral open extremity lesion . RESULTS: Bacteria were isolated from 10 of 89 LN (11.2%) and included Staphylococcus species, gram-negative rods, diphtheroids, and Peptostreptococcus . Three of the 10 LN were taken from extremities with open lesions; seven were not . In no case did organisms cultured from a groin LN correlate with its corresponding open extremity lesion . Four GWI developed after operation (4%) . In each case results of the groin LN cultures were negative . Three of the GWI were associated with an ulcerated or gangrenous lesion on the ipsilateral extremity (p = 0.08, odds ratio = 7.6), but in only one case did the organisms from the GWI correspond to that in the open lesion . The development of a GWI was strongly associated with insulin-dependent diabetes mellitus (p = 0.009, odds ratio = 22.9) . CONCLUSION: In conclusion, 11% of groin LN harbored bacteria, but none of these were associated with subsequent development of a wound infection . Instead, insulin-dependent diabetes mellitus and the presence of an open skin lesion on the ipsilateral extremity seemed to be associated with an increased risk of wound infection.

Arch Surg, 1993 Jun, 128(6), 691 - 5
Circulating and exudative polymorphonuclear neutrophil priming and oxidative capacity in anergic surgical patients; Tellado JM et al.; OBJECTIVES: To examine the oxidative capacity of circulating and exudate polymorphonuclear neutrophils from reactive patients and anergic patients before surgery to determine why anergic patients have increased sepsis-related mortality once an infectious complication develops . DESIGN: Prospective in vitro patient study . SETTING: Tertiary care, major university teaching hospital . PARTICIPANTS: Surgical patients admitted for major elective gastrointestinal surgery . MAIN OUTCOME AND MEASURES: We used flow cytometry and the dye 2-7-dichlorofluorescein diacetate to measure hydrogen peroxide production of circulating and exudate polymorphonuclear neutrophils at baseline and after stimulation with Staphylococcus epidermidis . RESULTS: We found that polymorphonuclear neutrophils were primed in the intravascular space as evidenced by increased numbers of formyl-methionyl-leucyl-phenylalanine receptors, increased hydrogen peroxide production at baseline, and increased hydrogen peroxide production with stimulation . These results were more evident in the anergic patient . After exudation, anergic polymorphonuclear neutrophils lost most of their capacity to produce additional hydrogen peroxide . CONCLUSIONS: The data suggest that this intravascular priming adversely affected polymorphonuclear neutrophils during exudation, more marked in the anergic patient, and may contribute to the sepsis-related mortality of the anergic patients.

Infect Immun, 1993 Jun, 61(6), 2445 - 52
Concomitant loss of conformation and superantigenic activity of staphylococcal enterotoxin B deletion mutant proteins; Metzroth B et al.; The T-cell-stimulating activity of staphylococcal enterotoxin B (SEB) is an important factor in the pathogenesis of certain staphylococcal diseases . To investigate the immunologically active domains of the SEB molecule, we have produced truncated fragments of recombinant SEB by C-terminal and N-terminal deletions . The fragments were expressed as fusion proteins with protein A, including a cleavage site to remove the protein A part . Mutant proteins were tested for the ability to stimulate human resting T cells and SEB-reactive T-cell clones . Deletion of only 9 amino acids from the C terminus leads to complete loss of T-cell-stimulating activity . Removing further amino acids from the SEB molecule did not lead to a reexpression of T-cell-mitogenic activity . A mutant protein, however, in which the 9 C-terminal amino acids were replaced with a tail of 68 amino acids encoded by the vector was fully active . Two mutant proteins with N-terminal deletions of 60 and 81 amino acids were inactive as well . A neutralizing monoclonal antibody against a conformational epitope lost binding with all the inactive mutant proteins only, whereas a monoclonal antibody recognizing an epitope involved in emetic activity reacted with all mutant proteins . These results suggest that even small deletions at the C terminus affect the three-dimensional conformation of the SEB molecule.

Chest, 1993 Jun, 103(6), 1912 - 3
Primary sternal osteomyelitis presenting as a pleural-based mass; Lo WK et al.; Osteomyelitis in uncommon locations can present unusual diagnostic difficulties . A patient with primary sternal osteomyelitis who presented with pain over the right supraclavicular area and a radiologic picture of a pleural-based right upper lung mass is discussed . A triple-phase bone scan was consistent with the diagnosis, and a needle aspiration of the mass revealed a staphylococcal abscess . Percutaneous drainage of the contiguous abscess and a prolonged course of antibiotic therapy cured the infection.

Acta Orthop Scand, 1993 Jun, 64(3), 273 - 6
Bacterial adherence to bioinert and bioactive materials studied in vitro; Oga M et al.; In vitro, bioinert stainless steel and titanium alloy, and bioactive sintered hydroxyapatite and hydroxyapatite-coated titanium materials were exposed to Staphylococcus epidermidis to study bacterial adhesion . Scanning electron microscopy showed that fibrous strands interconnected the adherent bacteria, and that background matrix enclosed bacterial colonies . This adherent mode of growth may reduce the susceptibility of the bacteria to host clearance mechanisms and antibiotic therapy . Adherence assays revealed that bacterial adherence to sintered hydroxyapatite was higher than to the other 3 materials.

Endocrinology, 1993 Jun, 132(6), 2654 - 8
Stimulation by Mn2+ and inhibition by Cd2+, Zn2+, Ni2+, and Co2+ ions of luteinizing hormone exocytosis at an intracellular site; Davidson JS et al.; Direct intracellular effects of the divalent cations Mn2+, Cd2+, Co2+, Ni2+, and Zn2+ on pituitary hormone exocytosis in a permeabilized cell system have not previously been investigated . We examined the effects of these ions on LH exocytosis in primary sheep pituitary cells permeabilized with Staphylococcal alpha-toxin . Mn2+ ions strongly stimulated LH release from permeabilized, but not intact, cells . Mn(2+)-stimulated LH release was ATP-dependent and sensitive to N-ethyl maleimide, indicating that it represents true exocytosis . Hormone release triggered by Ca2+ was inhibited by Cd2+, Zn2+, Co2+, and Ni2+ ions . Half-maximal inhibition of Ca(2+)-stimulated LH release was observed with 10 microM Cd2+, 30 microM Zn2+, 0.3 mM Co2+, and 1 mM Ni2+ . With the same order of potency these ions inhibited LH release stimulated by Ba2+, Mn2+, or phorbol ester plus cAMP, suggesting that they inhibit exocytosis at an intracellular site common to all these stimuli.

J Interferon Res, 1993 Jun, 13(3), 221 - 5
T-cell surface molecule expression and interferon-gamma production in human cord blood; Kruse A et al.; We investigated T-cell surface antigen expression and the production of interferon-gamma (IFN-gamma) and interleukin-2 (IL-2) by human cord and adult blood cells . Cord blood lymphocytes stimulated with Staphylococcus enterotoxin B (SEB) released only minimal titers of IFN-gamma and IL-2 in comparison with adult blood lymphocytes . Systematic analyses of several cell-surface molecules on untreated cord blood and adult blood T cells demonstrated a significant reduction of CD8+ subset numbers in cord blood . Furthermore, cord blood lymphocytes did not express the memory T-cell marker CD45RO . No differences were found in gamma/delta T-cell receptor (TCR), CD5, and CD25 antigen expression between untreated cord blood and adult blood . However, cord blood mononuclear cells showed a decreased CD25 antigen expression in comparison to those of adults following activation with SEB . These observations suggest that the decrease in the proportion of some T-cell subsets and the absence of CD45RO memory T cells may be responsible for the diminished lymphokine production of cord blood lymphocytes.

Parasite Immunol, 1993 Jun, 15(6), 355 - 9
Immunogenicity in rabbits and monkeys of influenza ISCOMs conjugated with repeated sequences of the Plasmodium falciparum antigen Pf155/RESA; Sjolander A et al.; Rabbits and monkeys were immunized with two fusion proteins, ZZ-M3 and ZZ-M5, coupled to pre-formed influenza virus membrane glycoprotein ISCOMs . The fusion proteins comprise two IgG-binding domains from staphylococcal protein A (ZZ) and repeated amino acid sequences from the C-terminal (M3) or central (M5) repeat regions of the Plasmodium falciparum antigen Pf155/RESA . The induced antibody responses were of long duration, could be efficiently boosted and were comparable to those obtained with Freund's Adjuvant . The produced antibodies reacted with M3, M5, protein A and the influenza glycoprotein, recognized Pf155/RESA and inhibited merozoite invasion in vitro . These results suggest that coupling of immunogens to pre-formed ISCOMs may be a basis for construction of multivalent subunit vaccines.

Lab Anim Sci, 1993 Jun, 43(3), 222 - 5
Pharmacokinetics of minocycline and vancomycin in rabbits; Nicolau DP et al.; The pharmacokinetic disposition of minocycline and vancomycin was studied in New Zealand White rabbits before initiating an experimental staphylococcal endocarditis protocol . Minocycline was administered in a multiple-dose regimen of 3 mg/kg i.v . every 12 h, 3 mg/kg i.v . every 8 h, and 6 mg/kg i.v . every 8 h . Vancomycin was given in a similar fashion using regimens of 75 mg/kg i.v . every 12 h and 50 mg/kg i.v . every 8 h . Multiple serum samples were obtained after the fifth dose and drug concentrations were analyzed by microbiologic assay . The pharmacokinetic parameters for each of the drug regimens were calculated using a two-compartment model by nonlinear least-squares regression . No statistically significant differences were noted in the volume of distribution or the half-life of the individual dosing regimens for either agent . As a result of this study, it appears that a minocycline regimen of 6 mg/kg i.v . every 8 h and a vancomycin regimen of 50 mg/kg i.v . every 8 h are appropriate dosing schemes for a comparative study of these agents in rabbits.

Protein Eng, 1993 Jun, 6(4), 441 - 8
Mutational analysis of the interaction between staphylococcal protein A and human IgG1; Cedergren L et al.; The interactions have been studied between an IgG-binding domain derivative based on domain B of staphylococcal protein A (designated Z) and human immunoglobulin G class 1 (IgG1) and its Fc fragment (Fc1) respectively . Five single amino acid substituted mutant forms of Z were constructed at the gene level, produced intracellularly in Escherichia coli, purified to homogeneity and characterized . Four of these Z variants, designated Z(L17D), Z(N28A), Z(I31A) and Z(K35A), were mutated in residues suggested to be involved in binding, based on the three-dimensional structure of the complex between a one domain protein A molecule and Fc1 {Deisenhofer, J . (1981) Biochemistry, 20, 2361-2370} . The fifth mutant protein, Z(F30A), had a mutation in a phenylalanine residue which was not expected to be involved in the interaction . Analysis by far UV circular dichroism spectroscopy suggests that all Z mutant proteins have similar folds . Their respective binding to human monoclonal IgG1 and to human recombinant Fc1 were studied in a competitive binding assay using radioactively labeled Z as a tracer, demonstrating that the mutant proteins with a substitution in the postulated binding surface showed a weakened binding to both the full-length antibody and the recombinant Fc1 . The affinity constants of the interactions as well as relative binding free energies from the parent Z molecule were calculated . These values were similar for each Z variant to both IgG1 and Fc1, suggesting that Fc and not Fab binding was measured also for IgG1 . However, the binding strengths differ significantly, and these binding properties were used to compare the contribution of each mutated amino acid residue in the Fc interaction.(ABSTRACT TRUNCATED AT 250 WORDS)

Protein Eng, 1993 Jun, 6(4), 417 - 23
Involvement of various amino- and carboxyl-terminal residues in the active site of the histidine-containing protein HPr of the phosphoenolpyruvate-dependent phosphotransferase system of Staphylococcus carnosus: site-directed mutagenesis with the ptsH gene, biochemical characterization and NMR studies of the mutant proteins; Kruse R et al.; The phosphocarrier HPr (heat stable protein) of Staphylococcus carnosus was modified by site-directed mutagenesis of the corresponding ptsH gene in order to analyse the importance of amino acids which were supposed to be part of the active centre of the protein . Three residues which are conserved in all HPrs, Arg17, Pro18 and Glu84, were mutated: Arg17 was changed to His (17RH) and Pro18 and Glu84 were changed into Ala (18PA and 84EA) . In addition, Leu86 was changed into Ala (86LA) and one mutant protein was missing the last six residues of the HPr (delta 83) . The wild type gene and all mutant genes were overexpressed and the gene products purified to homogeneity . Three-dimensional structures of wild type and mutant proteins were monitored by NMR spectroscopy . All five mutant HPrs had native conformations . The ATP-dependent HPr kinase can phosphorylate all HPr derivatives at Ser46 . The PTS activity of the amino-terminal HPr mutant proteins 17RH and 18PA was different compared to wild type HPr . In contrast, the carboxy-terminal mutant HPrs possessed a similar enzyme activity to the wild type HPr . The 17RH and 18PA HPrs with substitution near the active centre His15 showed a very slow phosphorylation by enzyme I but the further transfer of the phosphoryl group to enzyme III was also strongly inhibited . The enzyme activity of the HPr 17RH was significantly improved at low pH . NMR pH-titration experiments showed that Arg17 is not responsible for the low pKa of the active centre His15 but this positively charged residue is essential in this position for the HPr activity.

J Pediatr Surg, 1993 Jun, 28(6), 857 - 60
Focal gastrointestinal perforations not associated with necrotizing enterocolitis in very low birth weight neonates; Mintz AC et al.; Nine very low birth weight (VLBW) neonates (< 1,000 g) undergoing abdominal exploration for peritonitis were found to have focal perforations of the gastrointestinal (GI) tract and no clinical or histologic evidence of necrotizing enterocolitis (NEC) or other mechanical cause . Although most patients presented initially with clinical findings suggestive of NEC, none developed the traditional clinical or radiographic findings associated with this diagnosis . Most patients initially had normal bowel gas patterns or transient bowel distension on abdominal x-ray, followed within hours by a paucity of bowel gas or a totally gasless abdomen . Paracentesis was positive in 7 patients . A blue, purplish, or dusky discoloration of the abdomen was described in 7 patients prior to surgery . Surgery was performed at an average age of 16.7 days . In all, the bowel appeared grossly normal with the exception of a 0.3- to 1-cm focal perforation of the small intestine or colon . One patient had an additional similar perforation of the stomach . Treatment in most was simple exteriorization of the perforation . The one gastric perforation was oversewn . Biopsy specimens at the site of perforation from 4 patients were described as having focal necrosis without intrinsic bowel disease . Two were noted to have Candida invading the bowel wall . Unlike the typical bowel flora found on culture in infants with perforations due to NEC, these patients had cultures and histological specimens positive for Candida and/or Staphylococcus epidermidis . We conclude that focal GI perforations occurring in the VLBW infant represent a clinically distinct phenomenon and that the traditionally accepted diagnostic criteria for bowel perforation due to NEC are unreliable in this condition.(ABSTRACT TRUNCATED AT 250 WORDS)

J Clin Microbiol, 1993 Jun, 31(6), 1652 - 5
Dynamics of central venous catheter-related sepsis in rats; Paston MJ et al.; To determine when catheter-related sepsis clears after removal of an infected central venous catheter (CVC) and when a new sterile CVC can be inserted without risk of recolonization, a catheter infected with 10(5) CFU of Staphylococcus epidermidis per ml was inserted into 40 Fischer 344 rats . Five control rats had sterile catheters . Insertion of an infected CVC was followed by a significant rise in leukocytes after 4 days and the presence of S . epidermidis in lungs, livers, spleens, kidneys, and the catheter tip, as examined by bacteriological assay . After the infected catheter was removed, the rat recovered from the induced catheter-related sepsis within 12 h . When a new sterile CVC was inserted into the femoral vein, the leukocyte count remained normal, and all catheter tips and tissue cultures were sterile 4 days later.

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