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 .