J Comp Pathol, 1995 Nov, 113(4), 315 - 25 A murine model for the study of mycotic mastitis; Guhad FA et al.; This study established a murine model for the study of mycotic mastitis . The mammary glands of BALB/c mice were inoculated on the fifth day of lactation with graded doses (10(4), 10(5) and 10(6) cells) of a pathogenic strain of Candida krusei isolated from bovine mastitis . The animals were killed 1, 2, 3, 4 or 5 days after inoculation . In the infected mammary glands, the pathological reaction consisted of primary infiltration with heterophils and mononuclear cells, focal necrosis, formation of microabscesses, epithelial hyperplasia and some fibrosis . The severity of the changes was dose-dependent and increased with time after infection . An increase in the plasma concentrations of complement factors C1, C3c, C4 and C5, factor B and alpha-2-macroglobulin suggested that an acute phase response and activation of the complement system had occurred as a result of the infection. Cell Mol Biol (Noisy-le-grand), 1995 Nov, 41(7), 933 - 43 The use of digoxigenin-labelled probes to detect DNA sequences specific for plant pathogenic bacteria; Dessaux Y et al.; Southern blot hybridization is a valuable method in the assessment of the pathogenicity of bacterial strains or isolates . It is also a powerful tool for the demonstration of the presence of foreign DNA sequences in the genome of genetically-engineered plant cells . In this respect, cold, digoxigenin-labelled DNA probes can be used in place of classical radioactive probes, whether hybridizations are performed on bacterial genomic or plasmidic DNA, or on plant genomic DNA . The versatility of this cold labelling makes it suitable for the detection of unique bacterial genomic or plasmid sequences, even though these are located on large plasmids . The sensitivity of this cold probe technique also permits the detection of subpicogram quantities of DNA in plant genomic preparations . Their long term storage stability allows them to be frequently re-used over long periods of time, making this technique quite cost efficient. Gene, 1995 Oct 16, 164(1), 143 - 7 Isolation, sequencing and expression of the superoxide dismutase-encoding gene (sod) of Nocardia asteroides strain GUH-2; Alcendor DJ et al.; Nocardia asteroides (Na) superoxide dismutase (SOD) has been implicated as a virulence factor that allows the organism to survive intracellular killing by phagocytic cells . A full-length Na sod gene from a pathogenic strain of Na (strain GUH-2) was cloned from a recombinant phage library using the Mycobacterium tuberculosis (Mt) sod gene (Mt sod) as a probe . The promoter region and structural gene (624 bp) of Na sod was sequenced and nucleotide sequence comparisons reveal 77% homology with Mt sod . The Na sod gene also shares considerable sequence homology with sod of other mycobacterial species . In addition, conserved amino acid (aa) sequences important for metal binding indicate that Mn2+ is the preferred metal ion ligand for Na SOD . An Na sod expression plasmid, pYEX1, under transcriptional control of the Mt hsp70 promoter (pY6013), produced a 25-kDa protein product which showed SOD activity when stained in a native polyacrylamide gel and reacted with rabbit polyclonal antibody specific for Na SOD by Western blot . pYEX1, via transformation, was able to complement an Escherichia coli double sodAB mutant deficient in SOD production in the presence of paraquat (methyl viologen) which stimulates the production of superoxide radicals. Infect Immun, 1995 Oct, 63(10), 3780 - 9 Identification of two bvg-repressed surface proteins of Bordetella pertussis; Stenson TH et al.; Bordetella pertussis, the etiological agent of whooping cough, has the ability to modulate its phenotype in response to environmental conditions by using the BvgAS sensory transduction system which is encoded by the vir locus (now known as bvg) . The BvgAS system is part of a large family of two-component sensory transduction systems which are common to a number of pathogenic bacteria . Although much is known about the proteins which exist in the B . pertussis virulent (X-mode or phase I) phenotype, relatively little is known about the proteins produced in the avirulent (C-mode or phase III) phenotype . We used sodium dodecyl sulfate-polyacrylamide gel electrophoresis and isoelectric focusing techniques to demonstrate the existence of at least 22 vir-repressed molecules which are increased in the avirulent phenotype . In addition, a series of monoclonal antibodies which are specific for the surface of avirulent B . pertussis were developed . Using immunological and protein techniques, we characterized two of these antigens as surface-exposed proteins . One of these antigens is expressed only in B . pertussis but not in the related species B . parapertussis and B . bronchiseptica . The other antigen is also present in B . parapertussis and B . bronchiseptica but is expressed at lower levels which are not regulated by bvg . The identification and characterization of vir-repressed proteins (and the genes which encode and regulate them) may help elucidate a physiological role for modulation of this obligate human pathogen. J Acquir Immune Defic Syndr Hum Retrovirol, 1995 Oct 1, 10(2), 129 - 38 Effects of viral virulence on intrauterine growth in SIV-infected fetal rhesus macaques (Macaca mulatta); Tarantal AF et al.; Studies with a simian immunodeficiency virus (SIV)-infected fetal monkey model were conducted with a focus on fetal growth and viral pathogenesis . Twenty-six fetuses were inoculated in utero via ultrasound guidance with an uncloned pathogenic strain of SIV or vehicle during the second or third trimesters {gestational day (GD) 65, 110, or 130}, sonographically monitored weekly (biometrics, blood flow), then necropsied at incremental time points postinfection . Peripheral blood hematologic (complete blood counts, clinical chemistries), immunologic (immunophenotyping), and endocrine studies {insulin-like growth factor (IGF), IGF-binding proteins (IGFBP)} were conducted . Severe intrauterine growth restriction (IUGR), oligohydramnios, and altered lymphocyte counts were noted for fetuses infected on GD 65 . Less severe effects were detected for fetuses inoculated at the later time points, with severity dependent upon the length of SIV infection in utero . IGF studies indicated significant reductions in IGF-I and elevated immunoreactive levels of IGFBP-3 in infected fetuses during the third trimester . Parallel studies conducted with four fetuses infected on GD 65 with a nonpathogenic, molecularly cloned virus (SIVmac1A11) resulted in normal fetal growth, with no effects on hematopoiesis or IGF/IGFBP levels, and no evidence of clinical disease . Taken together, these studies show that (1) infection of fetuses during the early second trimester with an uncloned pathogenic strain of SIV results in severe IUGR and a disruption in the molar ratio of IGF:IGFBP-3, and (2) outcome of fetal SIV infection is determined by the timing of infection and the virulence of the viral inoculum. Acta Otolaryngol, 1995 Sep, 115(5), 653 - 7 Bacteria in middle ear effusions in children treated with tympanostomy; a 10-year series; Qvarnberg Y et al.; During the 10-year period, 1983-92, altogether 7,411 ears of 5,291 children with recurrent or chronic otitis media problems were treated with tympanostomy at our hospital in central Finland, The series was divided into three groups: i) infants aged 6-12 months undergoing primary tube treatment . ii) children aged 1 year or more receiving their first ventilation tube(s) in connection with adenoidectomy, and iii) children who had already had ventilation tubes inserted at least once before the present tympanostomy . Middle ear effusion (MEE) samples were obtained from 4,769 (64.3%) of the affected ears, 69.5% of all MEE cultures were negative for bacteria, whereas 20.2% grew pathogenic bacteria . S . pneumoniae was the most frequent pathogen in group 1, whereas H . influenzae was more frequent than S . pneumoniae in groups 2 and 3 . In only 3.7% of MEE cultures were beta-lactamase-producing strains of pathogenic bacteria found, either H . influenzae (0.9%) or M . catarrhalis (2.8%) . Comparison of the first and second 5-year periods ( 1983-87 vs . 1988-92) showed no significant changes in the occurrence of the various pathogenic bacteria . An increase was observed in beta-lactamase production for M . catarrhalis but not for H . influenzae strains. Acta Virol, 1995 Sep, 39(4), 205 - 209 Interaction of Rickettsia prowazekii strains of different virulence with white rat macrophages; Penkina GA et al.; The growth of mildly pathogenic strain E, its virulent revertant EVir, and prototype virulent strain Breinl of Rickettsia prowazekii in peritoneal macrophage cultures of outbread white rats (WR) was evaluated by light microscopy and bioassay in chick embryos (CE) . Macrophage cultures infected with strain E were characteristic by limited number of infected cells, poor or moderate accumulation of rickettsiae in individual cells, poor or nil spread of infectious process during first 7 days of infection, and the death of rickettsiae in cultures as determined by the bioassay in CE . Moreover, rickettsiae were not determined in 20.7% of infected macrophage cultures by either microscopic or bioassay methods . In contrast, the growth of virulent strains EVir and Breinl was characteristic by higher proportion of infected cells, considerable accumulation of rickettsiae, and intensive spread of infectious process within 5-7 days post infection (p.i.) . However, the intensity of infectious process in macrophage cultures was less expressed with strain EVir than with strain Breinl. J Clin Invest, 1995 Sep, 96(3), 1677 - 82 Priming for high interferon-gamma production induced by interleukin-12 in both CD4+ and CD8+ T cell clones from HIV-infected patients; Paganin C et al.; HIV-infected patients are defective in their ability to produce interleukin (IL)-12 in vitro in response to pathogenic bacteria and parasites . IL-12 enhances the patient's depressed natural killer cell cytotoxic activity, peripheral blood lymphocyte production of interferon-gamma (IFN-gamma), and proliferative T cell response in vitro to recall antigens, HIV antigens, alloantigens, and mitogens . However, these effects represent short-lived responses and imply the need for chronic IL-12 therapeutic administration in the clinical setting . To identify any long-term effects of IL-12 on T cell differentiation toward Th1 cells, peripheral blood T cells from 10 HIV-infected patients at different stages of disease were cloned by limiting dilution in the presence or absence of IL-12 and tested for cytokine production in response to stimulation with anti-CD3 antibodies and phorbol diesters IL-12 present during the first 2 wk of clonal expansion determined a stable severalfold enhancement on the ability of both CD4+ and CD8+ clones to produce IFN-gamma . Because priming for high IFN-gamma production is probably the most important mechanism by which IL-12 induces generation of efficient T helper type 1 (Th1) cells, these results suggest the possibility that IL-12 treatment in vivo of HIV-infected patients may stimulate a protective Th1 response against opportunistic pathogens and possibly HIV itself. Pediatr Dermatol, 1995 Sep, 12(3), 235 - 8 Cutaneous histoplasmosis in a child with hyper-IgM; Yilmaz GG et al.; Immunodeficiency with hyperimmunoglobulinemia M is a rare disease characterized by very low levels of IgG and IgA and normal or high levels of serum IgM and IgD . Recurrent and severe systemic infections with pathogenic bacteria are frequent if immunoglobulin replacement therapy is not given . Histoplasmosis is a systemic granulomatous mycosis due to Histoplasma capsulatum and characterized by a particular affinity for the reticuloendothelial system . Glabrous skin involvement in histoplasmosis is highly unusual except in patients with advanced human immunodeficiency viral disease . Cutaneous histoplasmosis and granulomatous reaction were diagnosed in a 5-year-old boy with hyper-IgM disease . The lesion improved after oral ketoconazole therapy . To our knowledge, this is the first case of cutaneous histoplasmosis associated with hyper-IgM to be reported. Pediatr Pulmonol, 1995 Aug, 20(2), 63 - 70 The relationship between infection and inflammation in the early stages of lung disease from cystic fibrosis; Balough K et al.; We examined the relationship of pulmonary infection and inflammation in cystic fibrosis (CF) by performing 31 bronchoalveolar lavages (BAL) in 14 young children with minimal lung disease from CF . While 10 of the 14 patients had elevated polymorphonuclear leukocyte (PMN) counts initially, only 4 had bacteria generally regarded as pathogenic in the recovered BAL fluid . Three of these 4 and 6 of the others had follow-up bronchoscopies at 6 months intervals . PMN counts remained normal for only one patient . However, pathogenic bacteria were recovered during the repeat BALs only in those patients who were colonized initially . Proinflammatory cytokines and proteinases were generally elevated, and interleukin-8 (IL-8) concentration correlated inversely with oxygen saturation (SaO2) . No complications of the procedure occurred . We conclude that BAL identifies inflammation and the presence of bacteria in the lower airway at an early stage of the disease . This information may be used to guide therapy in patients too young or otherwise unable to produce sputum . These data also suggest that inflammation is present early in the course of CF lung disease before colonization and infection of the lungs with potentially pathogenic bacteria occurs . Since inflammation appears to be the earliest detectable evidence of lung disease in CF, monitoring of inflammation with BAL may serve as a useful marker of clinical benefits from new treatments in patients with minimal lung disease. J Clin Invest, 1995 Aug, 96(2), 822 - 30 Endogenous expression of type II cGMP-dependent protein kinase mRNA and protein in rat intestine . Implications for cystic fibrosis transmembrane conductance regulator; Markert T et al.; Certain pathogenic bacteria produce a family of heat stable enterotoxins (STa) which activate intestinal guanylyl cyclases, increase cGMP, and elicit life-threatening secretory diarrhea . The intracellular effector of cGMP actions has not been clarified . Recently we cloned the cDNA for a rat intestinal type II cGMP dependent protein kinase (cGK II) which is highly enriched in intestinal mucosa . Here we show that cGK II mRNA and protein are restricted to the intestinal segments from the duodenum to the proximal colon, with the highest amounts of cGK II protein in duodenum and jejunum . cGK II mRNA and protein decreased along the villus to crypt axis in the small intestine, whereas substantial amounts of both were found in the crypts of cecum . In intestinal epithelia, cGK II was specifically localized in the apical membrane, a major site of ion transport regulation . In contrast to cGK II, cGK I was localized in smooth muscle cells of the villus lamina propria . Short circuit current (ISC), a measure of Cl- secretion, was increased to a similar extent by STa and by 8-Br-cGMP, a selective activator of cGK, except in distal colon and in monolayers of T84 human colon carcinoma cells in which cGK II was not detected . In human and mouse intestine, the cyclic nucleotide-regulated Cl- conductance can be exclusively accounted for by the cystic fibrosis transmembrane conductance regulator (CFTR) Cl- channel . Viewed collectively, the data suggest that cGK II is the mediator of STa and cGMP effects on Cl- transport in intestinal-epithelia. Infect Immun, 1995 Jul, 63(7), 2785 - 9 Characterization of the human immunoglobulin G Fc-binding activity in Prevotella intermedia; Labbe S et al.; Many pathogenic bacteria possess cell surface receptors which can bind immunoglobulins via the Fc portion . The aim of this study was to characterize the human immunoglobulin G (IgG) Fc-binding activity of Prevotella intermedia, a suspected etiologic agent of adult chronic periodontitis . The Fc-binding activity of P . intermedia on whole cells and on extracellular vesicles was demonstrated . Incubation of P . intermedia cells in the presence of Zwittergent 3-14 allowed complete solubilization of the Fc receptor from the cell surface . This cell envelope extract was thus used to characterize the Fc-binding activity . A microtiter plate assay using alkaline phosphatase-labeled Fc fragments showed that preincubation of the cell envelope extract with human IgG, human IgG Fc fragments, or human serum completely inhibited the Fc-binding activity . Partial inhibition was obtained with human IgG F(ab')2 fragments, whereas no inhibition occurred following preincubation with human IgA, carbohydrates, and selected proteins . Preincubation of the cell envelope extract with IgG from a variety of animals demonstrated that rabbit, mouse, rat, goat, and sheep IgG did not inhibit Fc-binding activity, whereas cow, pig, and dog IgG partially inhibited Fc-binding activity . A strong inhibition comparable to that obtained with human IgG was noted with monkey IgG . The Fc receptor of P . intermedia is thus different from the six types previously reported in other nonoral bacteria . Polyacrylamide gel electrophoresis and Western blotting (immunoblotting) analysis of the cell envelope extract revealed a major band with a molecular mass of approximately 65 kDa which reacted with peroxidase-labeled human IgG Fe fragments . Transmission electron microscopy showed a uniform distribution of the Fc receptor on the bacterial surface, as revealed by gold labeling . The Fc-binding activity demonstrated in this study may act as an additional virulence factor for P . intermedia by reducing IgG reactions with the bacterial cell. J Acquir Immune Defic Syndr Hum Retrovirol, 1995 Jul 1, 9(3), 291 - 6 Recent infection with human immunodeficiency virus and possible rapid loss of CD4 T lymphocytes; Holmberg SD et al.; To assess a hypothesized trend that persons recently infected with the human immunodeficiency virus (HIV) may have more rapid declines in absolute CD4 T-lymphocyte (CD4+ cell) counts than those who were HIV-infected in earlier years, sequential CD4+ cell counts in three groups who had definable dates of HIV seroconversion between 1978 and 1992 were reviewed . The CD4+ cell counts examined were from some of the longest extant studies in the United States: 100 homosexual and bisexual men engaged in ongoing observational cohort studies in San Francisco, Denver, and Chicago since 1978 (Group 1); 89 persons in South Carolina infected after 1986 (Group 2); and 155 injecting drug users participating in an observational cohort study in Baltimore since 1988 (Group 3) . For all groups, individually and in the aggregate, mean CD4+ cell counts declined rapidly in the first year after HIV infection and then stabilized . However, there was no clear trend for lower (or higher) CD4+ cell counts by fixed time after HIV seroconversion among those seroconverting in recent compared with earlier calendar years . These data do not support a hypothesized trend for more rapid loss of CD4 T lymphocytes--and, by implication, more pathogenic strains of HIV-1--among persons acquiring HIV infection in recent years. J Immunol, 1995 Jul 1, 155(1), 266 - 74 The extracellular neutral cysteine proteinase of Entamoeba histolytica degrades anaphylatoxins C3a and C5a; Reed SL et al.; We have shown previously that the extracellular cysteine proteinase of Entamoeba histolytica trophozoites activates the alternative pathway of complement by specifically cleaving C3 . This unique mechanism of complement activation leads to passive lysis of nonpathogenic, but not of pathogenic strains . In an attempt to investigate the relationship between the cleavage of complement components C3 and C5 and the pathogenesis of amebiasis, we investigated the production of the anaphylatoxins C3a and C5a, which have diverse effects on the host immune response . The concentration of proteinase required to cleave purified C5 was at least 5 to 10 times that needed for C3 cleavage, but these levels are easily obtainable as demonstrated by cleavage of 125I-labeled C5 during incubation with purified trophozoites . When the C3a-like cleavage fragments were purified by gel filtration, they were found to be extensively degraded during a 1-h incubation of C3 with the proteinase . Subsequent evaluations of the C3a- and C5a-like cleavage products generated earlier in the reaction using immunoblots and cellulose acetate electrophoresis revealed rapid degradation, even during incubation periods as short as 5 min . Because C-terminal fragments as small as 20 amino acid residues can mimic the biologic functions of C3a or C5a, we tested cleavage products for activity . In sensitive bioassays, including guinea pig platelet aggregation for C3a activity and chemotaxis for C5a activity, we demonstrated that proteolysis renders these molecules inactive . These studies suggest that the extracellular cysteine proteinase of E . histolytica, which is capable of activating the complement system, may also provide a mechanism to circumvent normal host immunity by inactivating the proinflammatory factors C3a and C5a. Curr Biol, 1995 Jul 1, 5(7), 706 - 9 Bacterial pathogenesis . When a turn off is a turn on; Strauss EJ; Pathogenic bacteria express distinct sets of genes at different stages in their life cycles; inappropriate expression of normally repressed genes during host colonization can interfere with bacterial survival. Virology, 1995 Jun 1, 209(2), 664 - 70 Do hemagglutinin genes of highly pathogenic avian influenza viruses constitute unique phylogenetic lineages? Rohm C, Horimoto T, Kawaoka Y, Suss J, Webster RG. Avian influenza A viruses of the H5 and H7 subtypes periodically cause severe outbreaks of disease in poultry . The question we wished to address in this study is whether these highly pathogenic strains constitute unique lineages or whether they and related nonpathogenic viruses are derived from common ancestors in the wild bird reservoir . We therefore compared the nucleotide and amino acid sequences of the hemagglutinin (HA) genes of 15 H5 and 26 H7 influenza A viruses isolated over 91 years from a variety of host species in Eurasia, Africa, Australia, and North America . Phylogenetic analysis indicated that the HA genes of H5 and H7 viruses that cause severe disease in domestic birds do not form unique lineages but share common ancestors with nonpathogenic H5 and H7 viruses . These findings predict that highly pathogenic avian H5 and H7 influenza A viruses will continue to emerge from wild bird reservoirs . Another important question is whether H7 influenza viruses found in mammalian species are derived from avian strains . We included eight equine influenza viruses and one seal isolate in the phylogenetic analysis of H7 HA genes . We could show that the HA genes of both, the equine and the seal viruses, shared ancestors with avian H7 HA genes . This indicates that currently circulating H7 viruses with an avian HA gene may have the potential to adapt to mammalian species and to cause an influenza outbreak in the new host. Infect Immun, 1995 Jun, 63(6), 2248 - 54 Products of enteropathogenic Escherichia coli inhibit lymphocyte activation and lymphokine production; Klapproth JM et al.; The aim of this study was to determine whether products of enteric bacteria are able to regulate lymphocyte activation and cytokine production . Whole bacteria and bacterial lysates from different strains of Escherichia coli were tested for their ability to inhibit cytokine production by peripheral blood mononuclear cells as determined by reverse transcription-PCR, Northern (RNA) blotting of cellular RNA, or enzyme-linked immunosorbent assay for cytokine protein . Lysates from two pathogenic strains of E . coli, enteropathogenic E . coli (EPEC) and enterohemorrhagic E . coli, inhibited mitogen-stimulated expression of interleukin-2 (IL-2), IL-4, IL-5, and gamma interferon . IL-1 beta, IL-6, IL-8, IL-10, IL-12, and Rantes mRNA expression was not affected . The inhibitory activity was dose dependent, protease and heat sensitive, nondialyzable, and not due to cellular toxicity . The inhibitory activity remained in EPEC strains having mutations in known virulence factors . Nonpathogenic E . coli HB101 transformed with a 22-kb cosmid clone derived from EPEC chromosomal DNA expressed the inhibitory activity . Thus, certain strains of pathogenic E . coli express a protein or proteins encoded by chromosomal genes that selectively inhibit lymphocyte activation and lymphokine production . Therefore, immunosuppressive factors produced by pathogenic bacteria could be important in modifying gastrointestinal immune responses in enteric bacterial infections or gastrointestinal autoimmune diseases. Am J Respir Crit Care Med, 1995 Jun, 151(6), 2073 - 80 Predisposing conditions to bacterial infections in chronic obstructive pulmonary disease; Jansen HM et al.; In normal airways, invasion of small numbers of pathogenic bacteria will not give rise to injury or local colonization . In chronic obstructive pulmonary disease, however, local conditions are changed, which may impair local defense systems and facilitate infection . These include: (1) factors promoting bacterial adherence and growth like the observed damaged airway epithelium in chronic bronchitis . The consequent changes in the composition of the epithelial lining fluid and impaired mucociliary clearance may be the most important pathophysiologic airway sequele in this respect; (2) aggravating generalized airway obstruction including mucus secretion, increase in mucus viscosity, and proliferation of submucosal smooth muscles, resulting in significant changes in airway geometry . This may change local conditions dramatically and so sustain factors promoting bacterial infections; (3) subversion of normally protective defense mechanisms into damaging host tissue at the mucosal level . Activated epithelial cell layers induce increased submucosal vascular leakage, edema, and inflammatory cell infiltration with subsequent tissue injury by locally produced cell products like free elastase . Specific bacterial products but also generally produced bacterial endotoxins may induce a local immune response resulting in the local production of high concentrations of antibodies and an invasion of specific effector cells . The role of these reactive cells or proteins may even be a primary one, in that they attack on (cellular) proteins, which increase their susceptibility for dysfunction in the defense line . For the clinicians, the new insights in the role of these aggravating factors in the development of recurrent bacterial airway infections in chronic bronchitis may be of major importance.(ABSTRACT TRUNCATED AT 250 WORDS) Ann Trop Med Parasitol, 1995 Jun, 89(3), 253 - 9 A comparative study of experimental caecal amoebiasis and the evaluation of amoebicides; Bhopale KK et al.; Caecal amoebiasis models (mouse, hamster and rat) were compared for amoebic infection and chemotherapeutic evaluation using a pathogenic strain of Entamoeba histolytica of human origin . Caecal infection in the hamster was of the acute type, with a large number of amoebae in the caecal tissue, whereas the amoebae in rats were seen in the lumen, on the mucosal surface . Amoebic lesions in the mouse caecum were of moderate severity . The mouse model responded to both metronidazole (tissue amoebicide) and diloxanide furoate (luminal amoebicide), whereas the hamster model only responded well to metronidazole and the rat model only to diloxanide furoate . Using the mouse as a primary screening model, a new oxadiazole compound, BTI 2405E, was found to have tissue and luminal amoebicidal activity . In rodent caecal models, a single dose of BTI 2405E was found to be more effective than one of metronidazole or diloxanide furoate . The mouse model appears to be the most useful for primary screening of anti-amoebic compounds. Exp Mycol, 1995 Jun, 19(2), 120 - 8 Intraspecific variation within populations of Fusarium oxysporum based on RFLP analysis of the intergenic spacer region of the rDNA; Appel DJ et al.; Fifty-six isolates of Fusarium oxysporum, including F . oxysporum f . sp . melonis and nonpathogenic strains, were chosen from a larger collection to represent diversity in vegetative compatibility groups (VCGs), mitochondrial DNA (mtDNA) haplotype, geographic distribution, and virulence . Using PCR, a 2.6-kb fragment including the intergenic spacer (IGS) region of the ribosomal DNA was amplified from each isolate . The enzymes EcoRI, Sau3A, CfoI, and AvaII, cut this fragment differentially, revealing 5, 6, 6, and 7 patterns, respectively . Among the 56 isolates, a total of 13 unique IGS haplotypes was identified . Among most F . o . melonis isolates . IGS haplotype correlated with VCG and mtDNA haplotype, but did not differentiate among races . However, a race 1 isolate found in VCG 0131 shared virulence, mtDNA, and IGS haplotypes characteristic of VCG 0134; this isolate may represent a conversion in VCG from 0134 to 0131 . Four nonpathogens shared the pathogen vegetative compatibility phenotypes . One race 1, 2 isolate associated with VCG 0134 shared both IGS haplotype and VCG with a nonpathogen, but these isolates did not share the same mtDNA haplotype . Another nonpathogenic isolate shared mtDNA and IGS haplotypes with pathogen group 0131 and may simply be an avirulent mutant of a pathogenic strain . For the other two nonpathogenic isolates, vegetative compatibility indicated a close relationship to the pathogen, but differences in both mtDNA and IGS haplotype suggest otherwise . Overall, the IGS haplotype was more variable among the nonpathogenic F . oxysporum VCGs among which 12 of the 13 IGS haplotypes were found . Nonpathogenic isolates that shared a common mtDNA haplotype, but were associated with different VCGs, often had different IGS haplotypes. Clin Otolaryngol, 1995 Jun, 20(3), 262 - 5 Factors associated with positive bacteriological cultures of chronic middle ear effusions; Heaton JM et al.; Pathogenic bacteria have been isolated from middle ear effusions in a number of studies . Our aim was to identify factors which predispose to patients having positive cultures . Over a 1-year period, prospective data were collected on patients admitted for myringotomy . Middle ear effusions were collected at the time of surgery using specially designed traps, and underwent microscopy and culture . Data on local weather parameters were obtained from the Meteorological Office in Edinburgh, UK and compared with the patterns of positive cultures . A higher proportion of cultures were positive in October, November and December and in February and May than in the other months of the years . We were not able to relate these variations to any of the meteorological data, with the possible exception of relative humidity, or to any other variable. Commun Dis Rep CDR Rev, 1995 May 26, 5(6), R86 - 90 Escherichia coli O157 infection associated with a farm visitor centre; Shukla R et al.; During the summer of 1994, four cases of bloody diarrhoea and/or haemolytic uraemic syndrome were reported to the consultants in communicable disease control in Nottingham and Leicester . One case was an adult, and there were three children aged 2 to 4 years . The initial investigation failed to reveal any common foodstuff as the cause of the outbreak, but all four cases had attended a farm visitor centre in Leicestershire in the three weeks before they became ill . A further three cases were found who had visited the same farm . A joint investigation took place with environmental health officers and the local veterinary investigation centre of the Ministry of Agriculture, Fisheries and Food . A questionnaire designed to ascertain possible sources of infection was sent to all cases . Several of the animals on the farm were sampled for Escherichia coli O157 and the farm's facilities for food preparation and hygiene were assessed . The pattern of infection did not suggest a point source for the outbreak . Analysis of responses to the questionnaires failed to reveal any common factor other than the visit to the farm, and all but one case remembered stroking and feeding the animals . Food preparation in the farm restaurant appeared to be satisfactory and there was no evidence of contamination of food with pathogenic bacteria . E . coli O157: H7, PT2, VT2 was isolated from four of the seven human cases and also from four cattle and six goats . Further analysis using restriction fragment length polymorphism (RFLP) showed that the four human strains were indistinguishable from nine of the 10 animal strains . It was concluded that the most likely cause of this outbreak was direct contact with the animals . This was further supported by poor handwashing facilities and lack of information for the visitors on the importance of personal hygiene. Virology, 1995 May 10, 209(1), 60 - 9 Interdependence of pathogenicity and replicability with potato spindle tuber viroid; Gruner R et al.; After the unexpected appearance of lethal symptoms on tomato plants infected with the PSTVd strain Intermediate Di, viroids were isolated and sequenced . It was found that a new strain, named RG 1, had been generated spontaneously in our greenhouse . In a different series of plant passages two new strains, named QF A and QF B, were detected which coexisted with the wild-type strain Di . Strains QF A and QF B showed intermediate symptoms when inoculated separately . In order to confirm the working hypothesis that the more pathogenic strain outcompetes the less pathogenic strain but strains of similar pathogenicity might coexist in the host, strains of different pathogenicity were mixed for inoculation in a ratio from 1:1 to 1:100 (more pathogenic:less pathogenic) . The concentrations of the individual strains were determined 6 weeks postinfection with the method of nondenaturing polyacrylamide gel electrophoresis, and the working hypothesis was confirmed . The total concentrations of viroids in infected plants were very similar, irrespective of whether severe, intermediate, or mild strains or mixtures of different strains were present . The mutations in all new strains (3 in RG 1, 2 in QF A, 3 in QF B) were located in the so-called virulence-modulating region . The mutations of strain RG 1 influenced dramatically the thermodynamic stability of the native rod-like structure, as determined experimentally by temperature-gradient gel electrophoresis . Since during replication a multihairpin structure is generated transiently which is transformed afterwards into the rod-like structure, a lower thermodynamic stability of the rod-like structure leads to a higher accumulation of the transient structure . It is assumed that the transient structure, which is active in replication as shown earlier, is essential also in pathogenesis . This model explains the experimentally determined interdependence between pathogenicity and replicability of PSTVd strains. Zhonghua Nei Ke Za Zhi, 1995 May, 34(5), 322 - 5 {A clinical and experimental study of L-form bacteria in 66 cases}; Zhang C et al.; In order to study the relationship between the time for establishing the diagnosis of infectious diseases and L-form bacteria, a series of clinical specimens taken from 321 cases of patients suspected to have infection were collected . Besides routine bacterial culture, special culture for L-form bacteria was also performed . The results were as follows: the rate of positive routine bacterial culture was 10.90% (35/321); the rate of negative routine bacterial culture but positive L-form bacterial culture was 20.56% (66/321) . In this study, L-form bacteria infection was treated with sensitive antibiotics and a satisfactory result was obtained . It is shown that L-form bacterial culture is very useful in detection of pathogenic bacteria and helpful to the therapy of infectious diseases . Ultrastructure organization of these bacteria was studied by using transmission electron microscope. Rev Inst Med Trop Sao Paulo, 1995 May-Jun, 37(3), 197 - 200 Influence of bacteria upon cytopathic effect and erythrophagocytosis of different axenic strains of Entamoeba histolytica; Gomes MA et al.; At this moment, the duality of species suggested for E . histolytica is being considered for discussion . In order to contribute to settling this question, we investigated the possibility of conversion of avirulent ameba to virulent ones, as well as, the possibility of increasing virulence of virulent strains, by means of association with bacteria . Five strains of E . histolytica were employed, two of them regarded as avirulent and three virulent ones . Amebas were associated with the bacteria Escherichia coli 055 and 0115, previously demonstrated as capable to modify the pathogenic behavior of E . histolytica . Changes in virulence of amebas were assessed by cytopathic effect upon cultured mammal cells and erythrophagocytosis . The virulence of pathogenic strains was significantly increased after bacteria association in opposition to what was observed for nonpathogenic ones, which were not influenced by bacteria association. Acta Paediatr, 1995 May, 84(5), 566 - 8 Bacterial colonization of the larynx and trachea in healthy children; Hjuler IM et al.; Fifty healthy children were included in the study; tracheal and laryngeal aspirations were performed after oral endotracheal intubation during minor surgery . The aspirates were evaluated and examined in the same way as aspirates from children suspected of pneumonia; 31 samples were accepted for the final analysis . After culturing, specimens from 30 children exhibited growth of potential pathogenic bacteria either from the larynx, the trachea or both . Prior to culture, bacteria were seen by microscopy in 24 samples from 30 children . These results indicate that the majority of healthy children carry potential pathogenic bacteria, not only in the larynx but also to a certain extent in the trachea . We conclude that aspirates from the larynx and the trachea are of limited value in the diagnosis of bacterial pneumonia in children. Environ Health Perspect, 1995 May, 103 Suppl 4, 73 - 7 Possible mechanisms of action of environmental contaminants on St . Lawrence beluga whales (Delphinapterus leucas); De Guise S et al.; A small isolated population of beluga whales (Delphinapterus leucas) that are highly contaminated by pollutants, mostly of industrial origin, resides in the St . Lawrence estuary, Quebec, Canada . Overhunting in the first half of the century was the probable cause for this population to dwindle from several thousand animals to the current estimate of 500 . The failure of the population to recover might be due to contamination by organochlorine compounds, which are known to lead to reproductive failure and immunosuppression in domestic and laboratory animals and seals . Functional and morphological changes have been demonstrated in thyroid gland and adrenal cortex in many species exposed to organochlorinated compounds, including seals . Morphological lesions, although different, were also found in belugas . Functional evaluation of thyroid and adrenal glands of contaminated (St . Lawrence) versus much less contaminated (Arctic) belugas is currently under way . Necropsy of St . Lawrence belugas showed numerous severe and disseminated infections with rather mildly pathogenic bacteria, which suggests immunosuppression . Organochlorine compounds and other contaminants found in beluga whales cause immunosuppression in a variety of animal species including seals . Thirty-seven percent of all the tumors reported in cetaceans were observed in St . Lawrence beluga whales . This could be explained by two different mechanisms: high exposure to environmental carcinogens and suppression of immunosurveillance against tumors . Overall, St . Lawrence belugas might well represent the risk associated with long-term exposure to pollutants present in their environment and might be a good model to predict health problems that could emerge in highly exposed human populations over time. Biochem Biophys Res Commun, 1995 Apr 26, 209(3), 1032 - 8 Calcium signalling initiated by CR1 (CD35) crosslinking is mediated by phagocyte Fc gamma receptors in cis; Ernst JD et al.; We have examined the role of complement receptor type 1 (CR1; CD35) in generating intracellular signals in phagocytic cells, particularly human neutrophils . We find that crosslinking of CR1 alone fails to result in an increase in intracellular ionized calcium {Ca2+}i . However, IgG bound to CR1 is able to interact with Fc gamma receptors to stimulate increases in {Ca2+}i . By examining signals generated in mixed populations of cells, we determined that calcium increases are observed only when CR1 and Fc gamma receptors are engaged on the same cell . Functional interactions between complement receptors and receptors for immunoglobulin G may promote clearance of pathogenic bacteria and fungi that bind limited quantities of complement and IgG. Obstet Gynecol, 1995 Apr, 85(4), 619 - 24 Fetal tissue derived from spontaneous pregnancy losses is insufficient for human transplantation; Hainline BE et al.; OBJECTIVE: To determine if sufficient fetal tissue with desirable transplant characteristics can be obtained from spontaneous abortions . METHODS: A survey of fetal tissues collected from newly diagnosed spontaneous pregnancy losses from three Indianapolis hospitals was conducted from December 1992 to September 1993 . Forty-nine of 356 mothers (13.8%) with spontaneous abortions or ectopic pregnancies consented to the evaluation of their products of conception by gross and microscopic pathologic examination, bacterial culture, cytogenetic analysis, cell culture, and maternal serologic tests . RESULTS: Forty-nine pregnancies (gestational age range 5-30 weeks) provided four identifiable embryos, 12 second-trimester fetuses, and one third-trimester fetus . Nine samples (18.4%) were of excellent or good quality on pathologic grading . Twenty-five of 38 samples tested (66%) grew pathogenic bacteria . Maternal serologic tests were negative for antibodies to human immunodeficiency virus, human T-cell lymphotropic virus, syphilis, and hepatitis B in all cases . One of 43 sera was reactive for hepatitis C, and 33 (77%) were positive for cytomegalovirus . Cytogenetic abnormalities were found in 25% of cultured samples . Five fetal brain samples had cell viabilities of 50% or more . Few viable fetal hepatocytes were found . Only two fetal brain samples (4.1%) were potential candidates for human transplantation . CONCLUSION: Spontaneous pregnancy losses yield minimal usable tissue for human transplantation because of a lack of embryonic or fetal tissues, delayed collection, decomposition, genetic abnormality, and bacterial contamination. Infect Immun, 1995 Apr, 63(4), 1409 - 14 Protein synthesis in Brucella abortus induced during macrophage infection; Lin J et al.; Brucella abortus is a facultative, intracellular, pathogenic bacterium that replicates within macrophages and resists macrophage microbicidal mechanisms . To study gene expression and to elucidate the defense mechanisms used by B . abortus to resist destruction within macrophages, protein synthesis by B . abortus was examined by pulse-labeling techniques during intracellular growth within J774A.1, a macrophage-like cell line . Prominent changes observed include increased synthesis of Brucella proteins with estimated molecular masses of 62, 28, 24, and 17 kDa . The 62-kDa protein was identified by immunoprecipitation analysis as Hsp62, a GroEL homolog . A protein of 60 kDa was expressed during acid shock and may represent a modified form of Hsp62 . The 28- and 17-kDa proteins have not been observed under any in vitro stress condition and presumably represent macrophage-specific induction . The 24-kDa protein comigrates with an unidentified protein induced by acid shock, designated Asp24 . Expression of Asp24 is optimal at pH values below 4.0 and within the first 3 h following a shift from pH 7.3 to 3.8 . This corresponds directly with a period of optimal bacterial survival at a reduced pH and suggests an active role for this protein in resistance to such environments . The identification of these gene products and the mechanisms controlling their expression is an important step in understanding the resistance of Brucella spp . to intracellular destruction within macrophages. HNO, 1995 Apr, 43(4), 257 - 60 {Does summer smog damage the nasal mucosa and contribute to bacterial rhinitis?}; Gehrckens R; Smog in hot summers contains noxious agents resulting from the combustion of fossil fuels whose levels are highest in industrial areas . Reactions of the oxygen radical of ozone with sulfur dioxides, nitrous oxides, hydrocarbons and the water molecules of the nasal mucous membrane presumably support the formation of acids such as H2SO4 or HNO3 (from H2SO3 or HNO2 {3, 4}) . Acid corrosion seems to damage the mucous membrane, leading to local erosions, bleeding, and necrotic changes . The collapsed local defense system and necrotic mucosa are an ideal culture medium for a wide spectrum of pathogenic bacteria . Main signs of tissue pathology are bleeding spots or pustules, nasal congestion, degenerative mucositis, pruritus, as well as epipharyngeal and pharyngeal irritation . Therapy is possible with topical or oral antibiotics . Prophylaxis includes avoiding touching the mucous membranes and reducing outdoor activity on hot summer days . Further clinical and scientific examination would be helpful in determining additional explanations. J Hepatol, 1995 Apr, 22(4), 468 - 73 Serial transmission of spongiocytic hepatitis to woodchucks (possible association with a specific delta strain); Parana R et al.; BACKGROUND/AIMS: Outbreaks of severe hepatitis have been reported from Africa and South America . Description of the cases has shown the histological hallmark to be the presence of ballooning hepatocytes with fat drops surrounding the nucleus (spongiocytes or morula cells) . METHODS: Experimental reproduction of this syndrome for the verification of a possible role of a specific HDV strain was performed by the inoculation of serum and liver extracts from African patients (Bangui-Central African Republic), who died with this syndrome, into American woodchuck carriers of WHV (WC 231,144), the results of which were then compared with animals inoculated with a reference wild HDV strain (WC 300,173,154), and those which received material from a European fulminant HDV case (WC 88,93) . RESULTS: Following the initial inoculation, the animals receiving African inocula had a delayed anti-HDV seroconversion, high mortality and showed the presence of spongiocytes, while the other animals had a classical evolution of HDV superinfection in woodchucks . Furthermore, the African inocula caused less inhibition of WHV replication, as well as a predominant cytoplasmic expression of HDAg, in contrast to the animals which received the other inocula . The second passage experiments gave similar results . CONCLUSIONS: We conclude that this peculiar form of HDV fulminant hepatitis can be experimentally reproduced and might be specifically related to a more pathogenic strain. PCR Methods Appl, 1995 Apr, 4(5), 265 - 8 DNA fingerprinting of crude bacterial lysates using degenerate RAPD primers; Sakallah SA et al.; Methods for identifying isolates of various pathogenic bacteria by DNA fingerprinting with random primers (RAPD) have been described recently . In these methods many primers are screened and the primers that generate the most informative DNA pattern are selected . A new strategy that simplifies the primer selection process for RAPD fingerprinting has been developed in our laboratory . In this approach, one or more degenerate nucleotides is introduced into the core RAPD primer sequence at various nucleotide positions . Results show that a single degenerate nucleotide in the primer sequence can significantly change the DNA profile obtained for the same template . The more removed the degenerate nucleotide is from the 3' end of the primer, the less dramatic is its effect on banding pattern . This method utilizing degenerate RAPD (D-RAPD) primers was tested on clinical isolates of Legionella pneumoniae, and results were confirmed with nondegenerate RAPD primers . Results obtained with D-RAPD primers were in total agreement with those obtained with nondegenerate RAPD primers . We propose that the use of a core RAPD primer sequence with one or more degenerate nucleotide(s) at various positions can expedite the generation of unique DNA fingerprints individual organisms . A general method for selecting the most useful fingerprinting RAPD primers is discussed. Infect Immun, 1995 Mar, 63(3), 917 - 25 Molecular cloning of a 30-kilodalton lysine-rich surface antigen from a nonpathogenic Entamoeba histolytica strain and its expression in a pathogenic strain; Bracha R et al.; A monoclonal antibody (MAb), 318-28, that specifically reacts with a 30-kDa antigen present on membrane surfaces of all nonpathogenic (NP) Entamoeba histolytica strains tested and which did not react with pathogenic (P) strains was used for the isolation of the cDNA coding for this antigen from an expression library of an NP E . histolytica strain . The deduced amino acid composition was rich in lysine residues (14.5%), with some sequence similarity to a polyadenylate-binding protein . Southern and Northern (RNA) blot analyses, as well as amplifications of DNA segments by PCR, indicate that a very similar gene (identity of 96.5%) exists in P strains of E . histolytica . Unexpectedly, the NP-specific antigen was also identified by MAb 318-28 on the surfaces of a cloned, xenically cultivated and well-characterized P strain (BNI:0591) that was recently isolated from a human liver abscess . Binding of the MAb, both to the cell surfaces and to Western blots (immunoblots), was abolished, however, upon axenization of the BNI:0591 cultures . Oligonucleotide primers, designed to anneal only to specific DNA sequences of the NP 30-kDa protein gene copy, amplified a DNA segment from P strain BNI:0591 which was identical in sequence to that of the NP 30-kDa protein gene . Our findings indicate that a P strain of E . histolytica can possess and express, under certain growth conditions, an antigen that is usually detected only in NP strains. Infect Agents Dis, 1995 Mar, 4(1), 47 - 54 Proteases and bacterial virulence: a view from the trenches; Goguen JD et al.; Many species of pathogenic bacteria produce cell-surface or secreted proteases . These enzymes have high potential to enhance bacterial pathogenesis through degradation of critical host proteins and by mimicking the activity of host regulatory proteases that control important zymogen systems . Although many bacterial proteases have been implicated in virulence, there is currently no system in which both rigorous demonstration of virulence enhancement in vivo and convincing identification of the important substrate molecules has been achieved . The difficulties inherent in addressing these issues is discussed, and several interesting systems under active investigation briefly described . The potential of extracellular protease as targets for drug development is also considered. Virology, 1995 Feb 20, 207(1), 240 - 5 Nucleotide sequences of the genes encoding the putative attachment glycoprotein (G) of mouse and tissue culture-passaged strains of pneumonia virus of mice; Randhawa JS et al.; The sequences of the genes encoding the putative attachment (G) proteins of pathogenic (strain J3666) mouse lung-passaged and nonpathogenic (strain 15) tissue culture-passaged strains of pneumonia virus of mice (PVM) have been determined . In both cases the major polypeptide was synthesised from the second open reading frame (ORF), a feature also found in the G gene of respiratory syncytial (RS) virus, another pneumovirus . However, the ORFs of the G genes of the two PVM strains were initiated at different nucleotide positions in the mRNA and comparison of hydrophobicity profiles revealed the presence of the putative amino-terminal cytoplasmic domain in the strain J3666 G protein and its absence in the predicted G protein of PVM strain 15 . In common with the G protein of RS virus, the gene product of both PVM strains contained a high serine, threonine, and proline content . Indirect immunofluorescence analysis of BSC-1 cells expressing the G gene products confirmed the surface location of the proteins . Thus, the absence of a cytoplasmic domain does not interfere with the translocation of the G protein of PVM strain 15 . In vitro translation of mRNA from the two PVM genes directed the synthesis of a larger polypeptide with the G gene of PVM strain J3666 than was seen with strain 15 G gene . In addition, a second protein was seen with strain J3666 mRNA which was the same size as the strain 15 G protein. Ned Tijdschr Geneeskd, 1995 Feb 18, 139(7), 324 - 7 {Underestimation of intestinal protozoa as a cause of diarrhea in family practice}; Mank TG et al.; OBJECTIVE . To assess the frequency of intestinal protozoa in stool samples of patients with diarrhoea in general practice . SETTING . General practitioners' laboratory in Haarlem, Netherlands . DESIGN . Descriptive study . METHOD . During one year (1 February 1992 to 31 January 1993) all stool samples from patients with diarrhoea visiting a general practitioner were examined according to a standard protocol consisting of bacterial and protozoal examination . RESULTS . Among 1703 stool examinations requested by general practitioners and performed according to the protocol, pathogenic protozoa were found in 10.8% and pathogenic bacteria in 8.6% . Of the 184 patients who tested positive for pathogenic protozoa 156 harboured Giardia lamblia, 22 Entamoeba histolytica and 6 Cryptosporidium spp . Pathogenic protozoa were predominantly found in patients with diarrhoea persisting for longer than 1 week and in cases with intermittent diarrhoea . In patients with acute diarrhoea (duration < 1 week) we predominantly found pathogenic bacteria (Campylobacyter jejuni) . If the search for protozoa in the stool samples would not have been performed routinely, 34% of the pathogenic protozoa (Giardia lamblia) would not have been found . CONCLUSION . Intestinal infections with protozoa are not rare in general practice . It seems worthwhile to perform protozoal examination of the stool samples in case of persistent diarrhoea. Am J Surg Pathol, 1995 Feb, 19(2), 224 - 8 Graft-versus-host-like colitis associated with malignant thymoma; Kornacki S et al.; A case of a patient with a malignant thymoma who developed an unusual form of colitis is reported . The patient was a previously healthy 20-year-old man who was referred to the Johns Hopkins Medical Institution for biopsy and resection of a mediastinal mass, which proved to be a malignant thymoma . During this hospitalization and subsequently, the patient developed severe chronic diarrhea, the etiology of which remained uncertain after routine work-up, including cultures . Colonoscopic biopsies revealed only minimal inflammation but numerous, prominent apoptotic lesions within crypt epithelium, suggestive of an autoimmune or graft-versus-host-like colitis . The patient, who was immunocompetent and human immunodeficiency virus (HIV) negative, had no known risk factors for graft-versus-host-disease (e.g., no blood transfusions, no transplantation history before diarrheal episodes) . Stool cultures for pathogenic bacteria and viruses were negative . The diarrhea and histologic findings eventually improved with steroid therapy yet returned on recurrence of the thymoma . This unusual form of colitis has not been previously reported to be associated with thymoma and is interesting in light of the role the thymus plays in immune regulation. Eur J Surg, 1995 Feb, 161(2), 67 - 71 Food deprivation increases bacterial translocation after non-lethal haemorrhage in rats; Bark T et al.; OBJECTIVE: To investigate whether brief fasting before the induction of hypotension by non-lethal haemorrhage may induce translocation of enteric bacteria to mesenteric lymph nodes or blood in rats . DESIGN: Laboratory experiment . SETTING: University departments of surgery and microbiology, Sweden . MATERIAL: 39 Male Sprague-Dawley rats . INTERVENTIONS: 20 animals were fasted for 24 hours, all 39 then underwent controlled haemorrhage for 60 minutes that reduced the blood pressure to 55 mm Hg . MAIN OUTCOME MEASURES: Differences in blood loss, blood glucose concentrations, and packed cell volume; and aerobic cultures of mesenteric lymph nodes and blood . RESULTS: Fasted rats (n = 20) lost 2.3% of blood volume compared with 2.8% in fed rats (p < 0.001) . Packed cell volume dropped by 11.3% in fasted rats and 16.5% in fed rats (p < 0.001) . Glucose concentrations rose by 7.0 mmol/l in fasted rats compared with 21.0 mmol/l in fed rats (p < 0.001) . Mesenteric lymph nodes contained enteric bacteria in 14/20 fasted rats compared with 6/19 fed rats (p < 0.05) . In 4 fasted rats blood cultures grew pathogenic bacteria compared with no fed rats (p = 0.11) . The number of bacteria found in mesenteric lymph nodes was significantly greater in fasted than in fed rats (p = 0.01) . CONCLUSIONS: Brief fasting before hypotension caused by non-lethal haemorrhage was associated with significantly increased bacterial translocation compared with fed animals . Increases in blood glucose concentrations and plasma refill may have had a protective effect in fed rats . These experiments may be of clinical relevance as elective operations are usually preceded by overnight fasting. Trends Microbiol, 1995 Feb, 3(2), 69 - 71 Tissue-culture invasion: fact or artefact? Miller VL. Although widely used, tissue-culture assays cannot be exact models of the conditions that are met in vivo by pathogenic bacteria . However, recent studies of specific mutants suggest that the model is good for highly invasive bacteria, but it remains to be seen if this is true for weakly invasive bacteria. Adv Dent Res, 1995 Feb, 9(1), 41 - 7 Regulation of hemin and iron transport in Porphyromonas gingivalis; Genco CA; As with other pathogens, a requirement for the in vivo growth of Porphyromonas gingivalis is that the organism must be capable of obtaining iron from the host . The ability to utilize hemin and hemin-containing compounds for nutritional iron has been documented for several pathogenic bacteria, including P . gingivalis; however, the mechanisms involved in hemin uptake are poorly defined . I have determined that P . gingivalis transports the entire hemin moiety into the cell by an energy-dependent mechanism and that the binding and accumulation of hemin are induced by growth of cultures in the presence of hemin . A model of hemin transport in P . gingivalis consistent with these results is presented . I have also found that, in P . gingivalis, hemin regulates the expression of several putative virulence factors; this in turn results in the increased virulence potential of P . gingivalis as assessed in an animal model . Regulation of hemin-responsive genes in P . gingivalis may occur by a negative regulator, as has been described in other pathogenic organisms. Antibiot Khimioter, 1995 Feb, 40(2), 27 - 31 {Antibiotic resistance of Escherichia of varying origin}; Smirnov IV et al.; Antibiotic resistance of enteroinvasive E . coli strains (O151:K-), i.e . the levels, associations and localizations of the genetic determinants was studied . The strains were isolated in an Infants' Home . The study was performed with the comparisons to the pathogenic and ordinary E . coli strains of another origin . It was shown that the pathogenic strains were mainly resistant to streptomycin, kanamycin and chloramphenicol . The resistance was due to the R plasmids . No correlation between the pathogenic serogroup and any combination of the markers was observed . The enteroinvasive E . coli strains isolated in the Infants' Home were characterized by a one-type combination of the markers, a one-type resistance level and a one-type plasmid pattern, as well as by increased levels of the chromosomal resistance to kanamycin and streptomycin. Acta Anat (Basel), 1995, 153(3), 210 - 9 Distribution of Escherichia coli heat-stable enterotoxin/guanylin/uroguanylin receptors in the avian intestinal tract; Krause WJ et al.; Pathogenic strains of enteric bacteria secrete small heat-stable toxins (STs) that activate membrane guanylyl cyclase receptors found in the intestine . The intestinal peptide agonists, guanylin and uroguanylin, are structurally related to STs . Receptors for 125I-ST were found throughout the entire length of the intestinal tract of all the birds examined . These receptors were restricted to intestinal epithelial cells covering villi and forming intestinal glands and were not observed in other strata of the gut wall . The most intense labeling of receptors by 125I-ST occurred in the region of the microvillus border of individual enterocytes . There appeared to be a decrease in receptor density distally along the length of the small intestine, although labeling of receptors by 125I-ST was observed throughout the small intestine and colon . Cellular cGMP accumulation responses to Escherichia coli ST and rat guanylin in the domestic turkey and duck were greater in the proximal small intestine compared to the distal small intestine or colon . Brush border membranes (BBM) isolated from the mucosa of proximal small intestine of turkeys exhibited agonist-stimulated guanylyl cyclase activity . The rank order potency for enzyme activation was E . coli ST > uroguanylin > guanylin . Competitive radioligand binding assays using 125I-ST and turkey intestine BBM revealed a similar rank order affinity for the receptors that was exemplified by the Kd values of ST 2.5 nM, uroguanylin 80 nM and guanylin 2.6 microM . It may be concluded that functional receptors for the endogenous peptides, guanylin and uroguanylin, occur in the apical membranes of enterocytes throughout the avian intestine . The receptor-guanylyl cyclase(s) of proximal small intestine were preferentially activated by uroguanylin relative to guanylin, but both endogenous peptides were less potent than their molecular mimic, E . coli ST. Prog Clin Biol Res, 1995, 392, 499 - 509 Anti-endotoxin activity of a novel synthetic lipid A analog; Kawata T et al.; Lipid As from non-toxic bacteria such as Rhodobacter capsulatus and Rhodobacter sphaeroides have been shown to antagonize the immunostimulatory effects of lipid A and LPS from pathogenic bacteria . We have biologically characterized a series of synthetic LPS antagonists including the proposed structures of the lipid A and R . sphaeroides containing fatty acid side chains ester-linked to the disaccharide backbone, as well as an analog of R . capsulatus lipid A containing ether-linked alkyloxy side chains (E5531) . In vitro assays utilizing LPS-stimulated human monocytes or whole blood demonstrated that low nanomolar concentrations of E5531 inhibited cellular activation as indicated by decreased release of the cytokines TNF-a, and interleukins-1, 6, and 8 . E5531 also inhibited LPS-induced release of cytokines and nitric oxide from murine macrophages . Synthetic antagonists at up to 100 microM were devoid of agonistic activity in murine and human in vitro systems . In vivo, E5531 blocked induction of TNF-a by LPS and reduced LPS-induced lethality in mice . These in vitro and in vivo results indicate that E5531 may have clinical therapeutic utility as an antagonist of endotoxin-mediated morbidity and mortality. Avian Dis, 1995 Jan-Mar, 39(1), 9 - 20 Association between pathogenicity of infectious bursal disease virus and viral antigen distribution detected by immunohistochemistry; Tanimura N et al.; Highly pathogenic infectious bursal disease virus (IBDV) strains (Ehime/91, DV86) and a moderately pathogenic strain (J1) were compared in order to clarify the association between the pathogenicity of IBDV and viral antigen distribution . Virus target cells in the bursa, thymus, spleen, and bone marrow were examined by transmission electron microscopy . Although all strains caused similar bursal atrophy, the highly pathogenic strains brought about a greater decrease in the thymic weight index and more severe lesions in the cecal tonsil, thymus, spleen, and bone marrow . Immunohistochemical detection of IBDV antigen in tissues from chickens infected with Ehime/91 and DV86 strains showed a higher frequency of antigen-positive cells in the spleen and bone marrow . Transmission electron microscopy indicated the presence of viral particles in the cytoplasm of epithelial reticular cells in the thymus and monocytes in the bone marrow . The results show that pathogenicity of field strains of IBDV correlates with lesion production in non-bursal lymphopoietic organs . The results also suggest that pathogenicity of IBDV may be associated with virus antigen distribution in non-bursal lymphopoietic organs. Parasitol Res, 1995, 81(3), 217 - 21 Genetic differentiation of pathogenic and nonpathogenic strains of Entamoeba histolytica by random amplified polymorphic DNA polymerase chain reaction; Mackenstedt U et al.; The random amplified polymorphic DNA polymerase chain reaction (RAPD-PCR) method was used to compare pathogenic and nonpathogenic strains of Entamoeba histolytica . DNA polymorphisms were detected among the different strains and dendrograms were constructed by PHYLIP and PAUP analyses to study the relationship of the strains . Both analyses resulted in identical results, which indicated that pathogenic strains of E . histolytica are closely related and clearly separated from the nonpathogenic strains . The results of this study agree with classification of the strains based on isoenzyme analyses . This suggests that RAPD-PCR is a valuable method in differentiating between strains of this parasite, and the results are consistent with the concept that pathogenic and nonpathogenic Entamoeba represent two different species. Allergy, 1995 Jan, 50(1), 90 - 3 Cry j I, a major allergen of Japanese cedar pollen, has pectate lyase enzyme activity; Taniguchi Y et al.; In the course of analyzing the partial amino acid sequences of Cry j I, a major allergen of Japanese cedar (Cryptomeria japonica) pollen, we found a peptide fragment which has a significant homology to some pectate lyase isozymes secreted by plant pathogenic bacteria . Therefore, we investigated whether Cry j I has pectate lyase activity . Cry j I reacted with polygalacturonic acid, resulting in the release of unsaturated uronide products . The optimum temperature and pH for the reaction were 60-70 degrees C and pH 10 . The enzymatic reaction had an absolute Ca2+ ion requirement . These characteristics were very compatible with the character of the pectate lyase isozymes reported previously . These results clearly show that Cry j I has pectate lyase activity. Clin Microbiol Rev, 1995 Jan, 8(1), 34 - 47 The family of bacterial ADP-ribosylating exotoxins; Krueger KM et al.; Pathogenic bacteria utilize a variety of virulence factors that contribute to the clinical manifestation of their pathogenesis . Bacterial ADP-ribosylating exotoxins (bAREs) represent one family of virulence factors that exert their toxic effects by transferring the ADP-ribose moiety of NAD onto specific eucaryotic target proteins . The observations that some bAREs ADP-ribosylate eucaryotic proteins that regulate signal transduction, like the heterotrimeric GTP-binding proteins and the low-molecular-weight GTP-binding proteins, has extended interest in bAREs beyond the bacteriology laboratory . Molecular studies have shown that bAREs possess little primary amino acid homology and have diverse quaternary structure-function organization . Underlying this apparent diversity, biochemical and crystallographic studies have shown that several bAREs have conserved active-site structures and possess a conserved glutamic acid within their active sites. Gene, 1994 Dec 30, 151(1-2), 185 - 90 A Coxiella burnetii gene encodes a sensor-like protein; Mo YY et al.; Two-component regulatory systems play important roles in the adaptive responses of many bacteria to environmental changes . The sensor proteins of these systems are highly conserved near their C-termini . We exploited this feature to isolate a gene encoding a putative sensor component from the obligate intracellular rickettsial parasite Coxiella burnetii (Cb) . Using degenerate primers and the polymerase chain reaction (PCR), we isolated a DNA fragment from a genomic library of Cb containing an open reading frame (ORF), sufficient to encode a 48-kDa protein . Sequence comparison revealed that the deduced protein shared high homology to members of the bacterial sensor protein family, particularly at three conserved regions of the C terminus . When the Cb sensor-like gene was cloned into a high-copy-number vector and introduced into an E . coli strain (phoM, phoR), the mutant expressed low levels of alkaline phosphatase activity, suggesting that the gene functioned as a sensor protein in E . coli . Consequently, we designated this gene qrsA (for Q fever agent regulatory sensor-like gene) . Because two-component regulatory systems have been implicated in a variety of cellular processes, including virulence determinants in some pathogenic bacteria, the identification of qrsA in Cb may shed light on how the pathogen adapts to extracellular changes during infection, as it proliferates in the phagolysosome. Structure, 1994 Dec 15, 2(12), 1227 - 40 Trimeric structure of a C-type mannose-binding protein; Weis WI et al.; BACKGROUND: Mannose-binding proteins (MBPs) are C-type (Ca(2+)-dependent) animal lectins found in serum . They recognize cell-surface oligosaccharide structures characteristic of pathogenic bacteria and fungi, and trigger the neutralization of these organisms . Like most lectins, MBPs display weak intrinsic affinity for monovalent sugar ligands, but bind avidly to multivalent ligands . RESULTS: We report physical studies in solution and the crystal structure determined at 1.8 A Bragg spacings of a trimeric fragment of MBP-A, containing the carbohydrate-recognition domain (CRD) and the neck domain that links the carboxy-terminal CRD to the collagen-like portion of the intact molecule . The neck consists of a parallel triple-stranded coiled coil of alpha-helices linked by four residues to the CRD . The isolated neck peptide does not form stable helices in aqueous solution . The previously characterized carbohydrate-binding sites lie at the distal end of the trimer and are separated from each other by 53 A . CONCLUSIONS: The carbohydrate-binding sites in MBP-A are too far apart for a single trimer to bind multivalently to a typical mammalian high-mannose oligosaccharide . Thus MBPs can recognize pathogens selectively by binding avidly only to the widely spaced, repetitive sugar arrays on pathogenic cell surfaces . Sequence alignments reveal that other C-type lectins are likely to have a similar oligomeric structure, but differences in their detailed organization will have an important role in determining their interactions with oligosaccharides. Structure, 1994 Dec 15, 2(12), 1181 - 9 Crystal structures of hevamine, a plant defence protein with chitinase and lysozyme activity, and its complex with an inhibitor; Terwisscha van Scheltinga AC et al.; BACKGROUND: Hevamine is a member of one of several families of plant chitinases and lysozymes that are important for plant defence against pathogenic bacteria and fungi . The enzyme can hydrolyze the linear polysaccharide chains of chitin and peptidoglycan . A full understanding of the structure/function relationships of chitinases might facilitate the production of transgenic plants with increased resistance towards a wide range of pathogens . RESULTS: The crystal structure of hevamine has been determined to a resolution of 2.2 A, and refined to an R-factor of 0.169 . The enzyme possesses a (beta alpha)8-barrel fold . An inhibitor binding study shows that the substrate-binding cleft is located at the carboxy-terminal end of the beta-barrel, near the conserved Glu127 . Glu127 is in a position to act as the catalytic proton donor, but no residue that might stabilize a positively charged oxocarbonium ion intermediate was found . A likely mechanism of substrate hydrolysis is by direct attack of a water molecule on the C1 atom of the scissile bond, resulting in inversion of the configuration at C1 . CONCLUSIONS: The structure of hevamine shows a completely new lysozyme/chitinase fold and represents a new class of polysaccharide-hydrolyzing (beta alpha)8-barrel enzymes . Because the residues conserved in the family to which hevamine belongs are important for maintaining the structure of the (beta alpha)8-barrel, all members of the family, including fungal, bacterial and insect chitinases, are likely to share this architecture . The crystal structure obtained provides a basis for protein engineering studies in this family of chitinases. J Virol, 1994 Dec, 68(12), 7800 - 9 Enhanced responsiveness to nuclear factor kappa B contributes to the unique phenotype of simian immunodeficiency virus variant SIVsmmPBj14; Dollard SC et al.; Infection with a variant of simian immunodeficiency virus, SIVsmmPBj14, leads to severe acute disease in macaques . This study was designed to investigate the functional significance of previously described mutations in the viral long terminal repeat (LTR) and to elucidate their contribution to the unique phenotype of SIVsmmPBj14 . LTR-directed transcription was measured by using luciferase reporter constructs that were transiently transfected into cultured cells . In a wide range of cell types, the basal transcriptional activity of the LTR from SIVsmmPBj14 was found to be 2- to 4.5-fold higher than that of an LTR from a non-acutely pathogenic strain . These LTRs differ by five point mutations and a 22-bp duplication in SIVsmmPBj14, which includes a nuclear factor kappa B (NF kappa B) site . Transcriptional differences between these LTRs were further enhanced by two- to threefold upon treatment of cells with phorbol ester or tumor necrosis factor alpha or by cotransfection with plasmids expressing NF kappa B subunits . Mutagenesis studies, and the use of a reporter construct containing an enhancerless promoter, indicate that these transcriptional effects are due principally to the 22-bp sequence duplication and the NF kappa B site contained within it . Finally, infectious virus stocks that were isogenic except for the LTR were generated . The LTR from SIVsmmPBj14 was found to confer an increase in the kinetics of virus replication in cultured cells . Inclusion of this LTR in recombinant SIVs also resulted in a two- to threefold rise in the extent of cellular proliferation that was induced in quiescent simian peripheral blood mononuclear cells . These studies are consistent with the hypothesis that LTR mutations assist SIVsmmPBj14 in responding efficiently to cellular stimulation and allow it to replicate to high titers during the acute phase of viral infection. J Am Vet Med Assoc, 1994 Dec 1, 205(11), 1574 - 6 Multifocal myositis associated with Sarcocystis sp in a horse; Traub-Dargatz JL et al.; Multifocal myositis was diagnosed in a 7-year-old Quarter Horse gelding on the basis of history and findings on physical examination, serum biochemical analysis, electromyography, and microscopic examination of frozen sections of muscle biopsy specimens . Histologic examination of the muscle specimen revealed multifocal accumulations of histiocytes, lymphocytes, and plasma cells, with attendant myofiber degeneration and necrosis . Parasitic cysts with morphologic characteristics of Sarcocystis sp were found in regions of myocyte degeneration and necrosis, and in regions of normal muscle . Based on a tentative diagnosis of Sarcocystis sp-induced myositis, the horse was treated with trimethoprim/sulfamethoxazole and pyrimethamine for 28 days, phenylbutazone for 5 days, and paddock rest for 30 days . At the end of treatment, the horse had gained 35 kg, its appetite had returned to normal, and muscle mass was returning to normal . Sarcocystis fayeri is the only Sarcocystis sp reported in equine muscle in the United States and is rarely associated with acute myositis or muscle atrophy . The development of clinical signs in this horse could have been the result of an underlying immunosuppression or infection with a particularly pathogenic strain or large infective dose of S fayeri. Ugeskr Laeger, 1994 Nov 28, 156(48), 7193 - 6 {Overheating and sudden infant death . Temperature regulation in relation to the prone position, the possible pathogenesis of sudden infant death}; Helweg-Larsen K et al.; The incidence of sudden infant death syndrome (SIDS) in Denmark varied in the period 1982-1991 between 1.5 and 1.9 per 1000 livebirths . In December 1991 recommendations concerning infants' sleeping position were published by The Danish National Board of Health in order to reduce the risk of SIDS . Babies were recommended to be placed in the supine or side position when sleeping . Parents have followed the guidelines . Most Danish infants are now sleeping on their back or in the side position . Simultaneously, the number of SIDS dropped from about 110 to 40 per year . The incidence decreased to 1.2 in 1992 and was further reduced in 1993 to 0.6 per 1000 live births . Referring to our knowledge of the infant's temperature regulation we discuss why the prone position is a risk factor for SIDS . The head is the site of up to 85% of heat loss in an infant in bed . Placed in the prone position, the infant is more likely to suffer a rise in body temperature, especially if this is combined with having a cold, being heavily wrapped and sleeping in a heated room . Preceding sudden death many infants are reported to have suffered from minor viral infections . These might per se increase the body temperature . Parents often wrap infants that have an infection too heavily, which in an infant sleeping in the prone position might increase the body temperature to a higher level than if sleeping supine . The body temperature influences the production of toxins from normal intestinal flora and from pathogenic bacteria.(ABSTRACT TRUNCATED AT 250 WORDS) J Biol Chem, 1994 Nov 4, 269(44), 27650 - 6 Characterization of the serine protease and serine protease inhibitor from the tissue-penetrating nematode Anisakis simplex; Morris SR et al.; A serine protease and a serine protease inhibitor were purified from infective larvae of the parasitic nematode Anisakis simplex . The serine protease was found to be trypsin-like and preferentially cleaved substrates with the basic amino acid arginine at the P1 position (Z-Gly-Pro-Arg-AMC (where Z is benzyloxycarbonyl), Km = 0.019 mM, and Z-Phe-Pro-Arg-AMC, Km = 0.013 mM) at rates similar to those determined for trypsin (0.002 mM and 0.006 mM, respectively) . However, the presence of a bulky hydrophobic residue at the P2 position (Z-Phe-Arg-AMC, Km = 13.3 mM, and Z-Ile-Leu-Val-Arg-AMC, Km = 24.7 mM) greatly decreased the rate of substrate hydrolysis . Internal amino acid sequence information was obtained from three endo Lys-C digestion fragments of the purified enzyme . These sequences were > 89% (33:37) identical with that of porcine trypsin . A second serine protease 85% (11:13) identical with that of a secreted tissue-destructive serine protease from the pathogenic bacterium Dichelobacter nodosus was also identified . The serine protease inhibitor was found to inhibit trypsin, elastase, and the Anisakis serine protease stoichiometrically, but did not inhibit chymotrypsin . The amino acid sequence of the amino terminus as well as two internal endo Lys-C fragments were determined . Approximately 96% (47:49) of the residues were identical with soybean trypsin inhibitor, indicating that this inhibitor belongs to the Kunitz-type family of inhibitors. Am J Trop Med Hyg, 1994 Nov, 51(5), 676 - 83 DNA probe-based classification of Simulium damnosum s . l.-borne and human-derived filarial parasites in the onchocerciasis control program area; Toe L et al.; The development of polymerase chain reaction-based methods using strain- and species-specific DNA probes for Onchocerca volvulus has permitted classification of individual parasites from every stage of the parasite's life cycle . This technology has been applied on a large scale basis by Onchocerciasis Control Program (OCP) in West Africa . The primary objective of the OCP in using the DNA probes was to obtain accurate estimates of the annual transmission potential of the blinding strain of O . volvulus . The DNA probe classification of larvae collected throughout the OCP area demonstrated that larvae of less pathogenic strains of O . volvulus and other filarial parasites carried by Simulium damnosum s.l . have resulted in a significant overestimation of the annual transmission potential for blinding onchocerciasis . This effect is particularly pronounced along the southern border of the OCP, where the blinding and less pathogenic strains of O . volvulus coexist, and in the north of the control area, where animal parasites, particularly O . ochengi, may even predominate . A second objective of the OCP in applying the DNA probe technology was to determine the distribution of blinding and less pathogenic O . volvulus in infected individuals along the southern border of the control area . Results obtained from these studies have generally confirmed the distribution pattern established by previous epidemiologic studies . In addition, DNA probe classifications have demonstrated that in areas where the blinding and less pathogenic strains of O . volvulus coexist, a single individual may simultaneously be infected with both strains of the parasite. Jpn J Antibiot, 1994 Nov, 47(11), 1576 - 81 {Clinical studies on cefozopran in pediatrics}; Morita H et al.; We conducted clinical studies on cefozopran (CZOP), a newly developed parenteral cephalosporin, for its clinical application in the field of pediatrics . 1 . A clinical study was performed on 16 children with infections, including 9 with pneumonia, 1 each with acute bronchitis, enterocolitis, purulent lymphadenitis, 4 with skin and soft tissue infections . CZOP was administered by 30 minutes intravenous drip infusion . Doses varying from 20 to 35 mg/kg body weight were given t.i.d . Lengths of treatment ranged from 4 to 14 days . 2 . Clinical efficacies were excellent in 10 and good in 6 cases, with an efficacy rate of 100% . The overall bacterial eradication rate for the pathogenic bacteria was also 100% . 3 . Side effect was noted in 1 case with skin rash . Abnormal laboratory test data were found in 5 cases including slight elevations of GPT in 4 cases and GOT in 2 cases. Proc Natl Acad Sci U S A, 1994 Oct 11, 91(21), 9720 - 4 Cellular vacuoles induced by Helicobacter pylori originate from late endosomal compartments; Papini E et al.; Pathogenic strains of Helicobacter pylori cause progressive vacuolation and death of epithelial cells . To identify the nature of vacuoles, the distribution of markers of various membrane traffic compartments was studied . Vacuoles derive from the endocytic pathway since they include the fluid-phase marker Lucifer yellow . Early endosome markers such as rab5, transferrin, and transferrin receptor, as well as the lysosomal hydrolase cathepsin D, are excluded from these structures . In contrast, the vacuolar membrane is specifically stained by affinity-purified antibodies against rab7, a small GTPase, localized to late endosomal compartments . The labeling of rab7 on vacuolar membranes increases as vacuolation progresses, without a concomitant increase of cellular rab7 . Cell vacuolation is inhibited by the microtubule-depolymerizing agents nocodazole and colchicine . Taken together, these findings indicate that the vacuoles specifically originate from late endosomal compartments. FEMS Microbiol Lett, 1994 Oct 1, 122(3), 227 - 31 Bidirectional gene transfer between Aspergillus fumigatus and Aspergillus nidulans; Borgia PT et al.; A genomic DNA library was constructed from a pathogenic strain of Aspergillus fumigatus using the cosmid vector pCosAX . Cosmid clones with homologies to the rodA, brlA, fluG, flbA or trpC genes from A . nidulans were isolated from the library . Each A . fumigatus clone was used to complement a strain of A . nidulans with a mutation in the homologous gene . A spontaneous white spored strain of A . fumigatus was isolated . The mutation was complemented by transforming the strain with a plasmid containing the wA gene from A . nidulans . The results from these experiments indicate a significant degree of structural and functional homology between genes from the organisms . These findings indicate the potential to exploit the methods and information available from A . nidulans to address questions related to human disease caused by A . fumigatus and the ability to use A . nidulans as a surrogate genetic host for characterizing A . fumigatus gene function. Plant Mol Biol, 1994 Oct, 26(1), 25 - 37 Thionins: properties, possible biological roles and mechanisms of action; Florack DE et al.; Thionins are low-molecular-weight proteins (M(r) ca . 5000) occurring in seeds, stems, roots and leaves of a number of plant species . The different members of this family of plant proteins show both sequence and structural homology, and are toxic to bacteria, fungi, yeasts and various naked cells in vitro . Toxicity requires an electrostatic interaction of the positively charged thionin with the negatively charged phospholipids making up the membrane, followed by either pore formation or a specific interaction with a certain lipid domain . This domain might be composed of phosphoinositides, which mediate transduction of environmental signals in eukaryotes . Their in vitro toxicity to plant pathogenic bacteria and fungi could reflect a direct role in plant defence, although, in view of the many divergent activities displayed by thionins both in vitro and in vivo, a biological role other than inhibition of microbial growth is equally plausible. Pathology, 1994 Oct, 26(4), 464 - 70 Murine chronic tubulointerstitial nephritis: induction by human uveitis mycoplasma-like organisms; Johnson L et al.; Mycoplasma-like organisms (MLO) are non-cultivated intracellular cell wall deficient pathogenic bacteria with a distinctive ultrastructural appearance . Diagnosis of MLO disease rests on finding the organisms in parasitized cells using a transmission electron microscope . MLO are a well studied cause of transmissible chronic plant vascular disease responsive to antibiotics . MLO have recently been found to cause human chronic progressive ophthalmic disease including uveitis . In human uveitis MLO are readily found within parasitized intraocular fluid leucocytes . Inoculation of human uveitis MLO into mouse eyelids produced a high incidence of chronic progressive ophthalmic disease including uveitis . MLO also disseminated to produce randomly distributed lethal systemic inflammatory disease . MLO parasitized leucocytes and microvascular alterations were found in the disease sites by electron microscopy . This report describes the chronic progressive tubulointerstitial nephritis in 12 of 100 human uveitis MLO eyelid inoculated mice versus 0 in 200 control mice (p < 0.0001) . MLO parasitized leucocytes accompanied by tubular and microvascular alterations were found by electron microscopy in all 12 inflamed kidneys versus 0 of 4 control kidneys . Pathobiology of the MLO-induced murine nephritis, resemblance of this nephritis to human idiopathic chronic tubulointerstitial nephritis, bacterial molecular biology, and antibiotic therapy of MLO disease are discussed. Proc Natl Acad Sci U S A, 1994 Sep 27, 91(20), 9431 - 5 Programmed cell death and AIDS: significance of T-cell apoptosis in pathogenic and nonpathogenic primate lentiviral infections; Estaquier J et al.; We have proposed that inappropriate induction of programmed cell death (PCD) or apoptosis, a physiological cell-suicide process, may play a role in the pathogenesis of AIDS . This model has been supported by several reports of abnormal levels of PCD in vitro in both CD4+ and CD8+ T cells from human immunodeficiency virus type 1 (HIV-1)-infected persons . To further assess the significance of such a process in AIDS pathogenesis, in vitro PCD was compared in HIV-1-infected persons and in various primate models that allow discrimination between pathogenic chronic lentiviral infection either in the same species, such as rhesus macaques infected with different simian immunodeficiency viruses (SIV), or in different species, such as SIV-infected African green monkeys and HIV-1-infected chimpanzees . Abnormal levels of PCD in CD4(+)-T-cell-depleted peripheral blood mononuclear cells (PBMC), containing the CD8+ T cells, were observed in both pathogenic and nonpathogenic models . However, abnormal levels of PCD in the CD8(+)-T-cell-depleted PBMC, containing the CD4+ T cells, was only observed in the two models leading to AIDS: HIV-1-infected persons and rhesus macaques infected with a pathogenic strain of SIV . This suggests that inappropriate T-cell PCD in HIV-1-infected persons involves two distinct processes: one, concerning CD4+ T cells, is closely related to AIDS pathogenesis; and the other, concerning CD8+ T cells, may be a consequence of immune stimulation with no direct link to AIDS pathogenesis. J Biol Chem, 1994 Sep 23, 269(38), 23617 - 24 Intramolecular self-cleavage of polysialic acid; Manzi AE et al.; Polysialic acid (PSA) is an unusual homopolymer of sialic acid (Sia) found on a limited number of animal glycoproteins and in the capsules of certain pathogenic bacteria . The biological properties of PSA are known to vary markedly with the length of the polymer . We confirm here that while the primary linkage unit of PSA (Sia alpha 2-8Sia) is more stable than commoner Sia linkages, PSA with > 3 Sia units is substantially more labile . A "limit digest" of PSA yields fragments of degree of polymerization (DP) = 2 and 3 and little monomeric Sia . In keeping with this, the fragmentation of PSA of DP 4 is non-random, with the internal glycosidic bond being more labile than those at the two ends . The accelerated breakdown of PSA involves an intramolecular mechanism that is not explained by lactone formation, cation effects, or specific secondary structural features . However, it is dependent upon the intactness of internal carboxyl groups, which have an anomalously high pKa . Thus, the instability of PSA appears to result from intramolecular self-cleavage of the glycosidic bonds of internal Sia units, in which the adjacent carboxyl group with a high pKa acts as a proton donor for general acid catalysis . This lability of PSA is seen under mildly acidic conditions that can be encountered in various physiological and pathological situations and thus has potential implications for neuronal adhesion, embryogenesis, and bacterial pathogenicity. Toxicology, 1994 Sep 6, 92(1-3), 269 - 86 Immunotoxicity of sulfuric acid aerosol: effects on pulmonary macrophage effector and functional activities critical for maintaining host resistance against infectious diseases; Zelikoff JT et al.; Despite the widespread occurrence of acidic sulfur oxides in the ambient environment and their potential risks to human health, effects associated with pulmonary immune defenses have been poorly studied . The current in vivo study was designed to provide some insight into this relatively unexplored area by investigating the impact of inhaled sulfuric acid on immune defense mechanisms critical for maintaining pulmonary resistance against infectious diseases . Results of this study demonstrate that repeated inhalation of sulfuric acid reduces the uptake and intracellular killing of pathogenic bacteria by exposed pulmonary macrophages, and depresses the activity/production of important biological modifiers critical for maintaining pulmonary immunocompetence . These findings have important implications for human health, and may contribute to a better understanding of the possible mechanism(s) underlying the epidemiological evidence which suggests an association between total sulfates in the ambient air and increased incidence of acute bronchitis and lower respiratory illness in school-age children. Microbiology, 1994 Sep, 140 ( Pt 9), 2309 - 13 Ethylene production by strains of the plant-pathogenic bacterium Pseudomonas syringae depends upon the presence of indigenous plasmids carrying homologous genes for the ethylene-forming enzyme; Nagahama K et al.; The molecular characteristics of the ethylene-forming enzymes of strains of Pseudomonas syringae were tested . The ethylene-producing activities of the nine strains as measured in vivo and in vitro were similar, except for that of P . syringae pv . mori M5 . A polyclonal antibody and a DNA probe for the ethylene-forming enzyme from P . syringae pv . phaseolicola PK2 were prepared to investigate homologies among the proteins and genes for the ethylene-forming enzymes . With the exception of P . syringae pv . mori M5, eight strains tested expressed the same antigen as the ethylene-forming enzyme from P . syringae pv . phaseolicola PK2 and were homologous to DNA sequences on indigenous plasmids . Molecular masses of antigenic proteins from all ethylene-producing strains were 40 kDa . The N-terminal amino acid sequence of the purified ethylene-forming enzyme from P . syringae pv . glycinea KN130 was identical to that of the enzyme from P . syringae pv . phaseolicola PK2 . These results show that the ethylene-forming enzymes encoded by the indigenous plasmid(s) in the pathogenic bacteria examined were similar. J Antibiot (Tokyo), 1994 Sep, 47(9), 976 - 81 Three new reduced anthracycline related compounds from pathogenic Nocardia brasiliensis; Maeda A et al.; Three new metabolites were isolated from a pathogenic bacterium, Nocardia brasiliensis IFM 0075 strain, a producer of a new anthracycline antibiotic (SO-075R1) and its mutant strain (IFM 0075-13-1) . The structural studies showed that they are reduced anthracyline related compounds . Some biosynthetic routes of these metabolites were discussed. FEMS Microbiol Lett, 1994 Sep 1, 121(3), 337 - 42 The Brucella abortus vaccine strain B19 carries a deletion in the erythritol catabolic genes; Sangari FJ et al.; Brucella abortus B19, an avirulent strain obtained by spontaneous mutation, is used worldwide as a vaccine for the control of bovine brucellosis . B19 differs from other B . abortus strains in its sensitivity to erythritol . We took advantage of a previously obtained erythritol sensitive Tn5 insertion mutant of B . abortus 2308 to clone the chromosomal region containing erythritol catabolic genes from this representative pathogenic strain and from the vaccine strain B19 . Physical mapping with restriction endonucleases and nucleotide sequence determination revealed the existence of a 702 bp long deletion, occurring between two short direct repeats, in the chromosome of B19 . This deletion rendered the B19 strain sensitive to erythritol . Two oligonucleotides whose sequences flank this deletion provided an easy method to differentiate B19 from all other B . abortus isolates. Eur J Biochem, 1994 Sep 1, 224(2), 397 - 405 Sequence variation of the hydroxymethyldihydropterin pyrophosphokinase: dihydropteroate synthase gene in lines of the human malaria parasite, Plasmodium falciparum, with differing resistance to sulfadoxine; Brooks DR et al.; Dihydropteroate synthase (H2Pte synthase) is the target of the sulfur-based antimalarial drugs, which are frequently used in synergistic combination with inhibitors of dihydrofolate reductase (H2folate reductase) to combat chloroquine-resistant malaria . We have isolated the H2Pte synthase coding sequence of the most pathogenic human parasite Plasmodium falciparum . It forms part of a longer coding sequence, located on chromosome 8, that also specifies 6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase (CH2OH-H2pterinPP kinase) at its 5' proximal end . This domain is unusually large, with two long insertions relative to other CH2OH-H2pterinPP kinase molecules . To investigate a possible genetic basis for clinical resistance to sulfa drugs, we sequenced the complete H2Pte synthase domains from eleven isolates of P . falciparum with diverse geographical origins and levels of sulfadoxine resistance . Overall, point mutations in five positions were observed, affecting four codons . Parasite lines exhibiting high-level resistance were found to carry either a double mutation, altering both Ser436 and Ala613, or a single mutation affecting Ala581 . The mutations at positions 436 and 581 have the same location relative to each of two degenerate repeated amino acid motifs that are conserved across all other known H2Pte synthase molecules . The amino acid alteration at residue 613 is identically positioned relative to a different conserved motif . The fourth amino acid residue (437) affected by mutation, though adjacent to the apparently crucial residue 436, shows no obvious correlation with resistance . Although these mutations have no exact counterparts in any other organism, that at position 581 falls within a region of three amino acids where H2Pte synthase is modified in various ways in a number of sulfonamide-resistant pathogenic bacteria . Copy-number analysis indicated that there was no amplification of the H2Pte synthase domain in resistant parasite lines of P . falciparum, compared to sensitive lines. Med Hypotheses, 1994 Aug, 43(2), 81 - 5 Can superantigens trigger sudden infant death? Lindsay JA, Johnson HM, Wallace FM, Soos JM. A majority of sudden infant death syndrome (SIDS) victims have respiratory or gastrointestinal infections prior to death . This has led to an investigation of the role of pathogenic bacteria and the potentially lethal toxins they produce as triggers for sudden infant death . A small group of bacteria have been consistently identified in SIDS victims as compared to controls, and remarkably, three of these produce superantigenic toxins . Superantigens exert a powerful effect on the immune system, stimulating T-cells, which subsequently induces the formation of large amounts of cytokines . Generation of an overwhelming inflammatory response may lead to death by shock, or other, as yet unrecognized effects of the toxin on the respiratory or cardiac systems . A SIDS/superantigen model is proposed which may explain many of the pathological characteristics of SIDS and establish quantifiable markers for SIDS. Chest, 1994 Aug, 106(2), 531 - 4 Tracheal aspirate correlates with protected specimen brush in long-term ventilated patients who have clinical pneumonia; Rumbak MJ et al.; STUDY OBJECTIVE: This study was undertaken to determine whether tracheal aspirate cultures correlate with protected specimen brush (PSB) cultures in the diagnosis of probable ventilator-associated pneumonia (VAP) . DESIGN: Retrospective evaluation of 52 episodes of clinical pneumonia in 38 patients who underwent bronchoscopy and PSB as well as tracheal aspirate cultures . SETTING: The study took place in long-term, acute care hospital associated with a university medical school . This hospital specializes in ventilator-assisted patients . PATIENTS: The patient population consisted of long-term ventilated patients (average ventilation time was 22 weeks; range, 4 weeks to 3 years) who presented with the clinical diagnosis of VAP (fever, increased white blood cell count, new infiltrate on chest radiograph, and bronchorrhea) . No patient had received antibiotics for the preceding 5 days at the time of bronchoscopy or tracheal aspirate culture . MEASUREMENTS: The tracheal aspirate and PSB culture and sensitivities results . RESULTS: Identical organisms were recovered in both the tracheal aspirate and PSB cultures in 36 of 52 episodes of VAP (69 percent) . No organism was recovered in either the tracheal aspirate or the PSB in 4 of 52 suspected episodes (8 percent) . Positive bacterial cultures in the tracheal aspirate but not the PSB were found in 8 of 52 (15 percent) episodes . In 3 of 52 episodes (6 percent), 1 isolate of pathogenic bacteria was found on PSB and 2 were found on tracheal aspirate cultures . However, all three isolates had the similar antibiotic sensitivities . In the final episode, the PSB culture grew an organism that was not present in the tracheal aspirate culture (2 percent) . When comparing the tracheal aspirate with the PSB, the following were calculated: sensitivity = 97.7 percent; specificity = 50 percent; positive predictive value = 91.3 percent; and negative predictive value = 80 percent . CONCLUSION: Tracheal aspirate cultures correlate with PSB cultures in patients receiving long-term ventilation who have clinical pneumonia, and they can be used to direct initial antibiotic therapy in this group of patients. Biochemistry, 1994 Jul 26, 33(29), 8641 - 50 Structural characteristics for biological activity of heat-stable enterotoxin produced by enterotoxigenic Escherichia coli: X-ray crystallography of weakly toxic and nontoxic analogs; Sato T et al.; Heat-stable enterotoxin (ST) produced by a pathogenic strain of Escherichia coli exerts its function by binding to a membrane-bound guanylyl cyclase on intestinal epithelial cell membranes, which in turn catalyzes the production of cyclic GMP as a second messenger in the cells . To elucidate the structural requirements for the biological activities of ST, we synthesized {Mpr5,Gly13}STp(5-17) and {Mpr5,Leu13}STp(5-17), which are weakly toxic and nontoxic analogs of STp, in which the toxic domain consists of the sequence from Cys at position 5 to Cys at position 17 . In these analogs, Cys at position 5 is replaced by Mpr (beta-mercaptopropionic acid) and Ala at position 13 by Gly and Leu, respectively . We examined these analogs by X-ray diffraction analysis using direct methods and refined the structures to crystallographic R factors of 7.3% and 6.6% using 5492 and 5122 data, respectively, observed > 3 sigma (Fo) with a resolution of 0.89 A . These peptides have a right-handed spiral structure consisting of three structural segments: an N-terminal 3(10) helix, a central type I beta-turn, and a C-terminal type II beta-turn . These structures show minor differences from that of {Mpr5}STp(5-17), the fully toxic analog of heat-stable enterotoxin {Ozaki et al . (1991) J . Biol . Chem . 266, 5934-5941}, suggesting that the decrease and loss of the biological activities of {Mpr5,Gly13}STp(5-17) and {Mpr5,Leu13}STp(5-17), respectively, are not caused by structural changes but are associated with the direct interaction of Ala13 with the receptor protein . Careful comparison of these structures in crystalline states revealed that ST has the following structural characteristics: (i) inherent flexibility at the junctions of the three segments and in the central segment, which includes the putative receptor-binding residues, Ala13, (ii) a specific hydrophobic character around the central segment, and (iii) an unexpected C-terminal folding similar to those of functionally unrelated peptides that are known to be ionophores. J Pediatr Ophthalmol Strabismus, 1994 Jul-Aug, 31(4), 246 - 50 Value of bacterial culturing in the course of congenital nasolacrimal duct (NLD) obstruction; MacEwen CJ et al.; The role of infection in the etiology and persistence of congenital nasolacrimal duct (NLD) obstruction is examined in a group of 334 infants who had conjunctival swabs cultured . One hundred and fifty eight (47%) of these had evidence of NLD obstruction and 176 (53%) did not . The types of organism grown from those with and without NLD obstruction were similar and occurred in almost equal proportions in each group . In addition, the rate of spontaneous resolution in those with NLD obstruction was the same, whether pathogenic bacteria were grown or not . There were no cases of orbital cellulitis, dacryocystitis, or ocular infection in those with NLD obstruction and no suggestion that secondary infection was more common in this group. Vet Microbiol, 1994 Jul, 41(1-2), 75 - 86 Characteristics associated with pathogenicity of avian septicaemic Escherichia coli strains; Fantinatti F et al.; Seventeen strains of E . coli, isolated from chickens with colisepticaemia, were studied with respect to their pathogenic characteristics including: serum resistance, toxin production, pathogenicity for one-day-old chicks, colicin production, adherence to and invasiveness of HeLa cells, plasmid DNA profile and SDS-PAGE electrophoresis of membrane proteins, as well as electron microscope studies and hemagglutination tests for fimbriae . We concluded that the adherence to and the invasiveness of HeLa cells were not related to the pathogenicity of these strains for chickens . Plasmid profiles were not related to the bactericidal activity of the serum . Toxin production was correlated to the highest levels of pathogenicity . Some of the strains had mannose-resistant fimbriae . SDS-PAGE of membrane proteins of all the strains which were either not pathogenic or which had a very high LD50 lacked two major protein subunits of 40.7 kDa and 28.8 kDa found only in pathogenic strains. S Afr Med J, 1994 Jul, 84(7), 389 - 93 Control of an amoebiasis outbreak in the Philippi area near Cape Town; Whittaker S et al.; Previous studies in Durban have shown that serological investigations, in combination with iso-enzyme electrophoresis, are invaluable for monitoring the endemicity of pathogenic strains of Entamoeba histolytica . We therefore proposed that antibody profiles could be used to detect epidemic situations . An outbreak of amoebiasis in the normally non-endemic Philippi area near Cape Town provided an opportunity for testing this hypothesis . Seven of 9 patients presenting at a district hospital with invasive amoebiasis originated from a single farm in Philippi . Iso-enzyme electrophoresis and serological investigations were used to monitor the endemicity of amoebiasis on 16 of the 49 farms in this district . In an attempt to contain disease transmission all inhabitants on farms from which patients came (including those where cyst-passers were identified) and all seropositive subjects were treated . The antibody profiles proved invaluable for confirming that the farm from which the hospitalised patients originated was the central focus of the outbreak, and also identified subjects infected with pathogenic zymodemes of E . histolytica on the adjacent 4 farms . On all 5 of these farms, 62.5-100% of seropositive subjects were strongly positive . In contrast weak to negative serological responses occurred on the remaining 11 farms . In addition the success of treatment was indicated by a notable drop in strong seropositive responses on the affected 5 farms to 11.5% within 9 months . The infection pathways implied that the pathogenic strain of E . histolytica was introduced into this non-endemic area by a foreigner from an endemic area; this suggests that the pathogenicity of E . histolytica is an immutable stable feature. J Periodontol, 1994 Jun, 65(6), 631 - 5 Sequential manifestation of different forms of early-onset periodontitis . A case report; Shapira L et al.; Pathogenic bacteria constitute the primary extrinsic agent in the etiology of early onset periodontitis . However, the risk of developing periodontal disease is not equal for all individuals, suggesting host factors are involved in determining an individual's disease susceptibility . In this report, a case of an otherwise healthy female, who exhibited prepubertal periodontitis (PPP) at age 10, juvenile periodontitis (JP) at age 13, and rapidly progressive periodontitis (RPP) at age 29 years, is presented . Microbial, immunological, and genetic features of the case are presented . PPP, JP, and RPP are considered distinct disease entities, albeit with similar pathology and pathogenesis, yet all were manifest sequentially in the same individual . This report presents the idea that certain individuals are predisposed to early-onset periodontal diseases and the early identification of risk factors is important in the management of these individuals. Zentralbl Veterinarmed B, 1994 Jun, 41(4), 229 - 36 Invasion and replication of Brucella abortus in three different trophoblastic cell lines; Samartino LE et al.; This study was performed to compare the replication of the pathogenic strain Brucella abortus 2308 in three trophoblastic cell lines derived bovine placentas at different gestational stages . The trophoblastic cell lines were obtained from a 13-15 day embryo, from 5-month placentomal tissue and from an 8-month extra-placentomal portion of the placenta . The infection rate was similar in all cell lines at 4 h . Colony-forming Units were counted at 4, 8, 12, 24 and 30 h post-inoculation . At 12, 16, 24 and 30 h B . abortus rapidly replicated within the 5-month and 8-month trophoblastic cell lines, but grew slowly within trophoblastic cells derived from embryonic tissue . Electron microscopic studies consistently showed clusters of B . abortus in trophoblastic cells derived from 5- and 8-month placentas, while few cells of the embryonic line were infected and these contained only 1-2 bacteria per cell . It was concluded that B . abortus can infect trophoblastic cells throughout the gestational period but bacterial multiplication does not occur in these cells before middle or late gestation. Infect Immun, 1994 May, 62(5), 1528 - 33 Ureaplasma diversum infection in vitro alters prostaglandin E2 and prostaglandin F2a production by bovine endometrial cells without affecting cell viability; Kim JJ et al.; Bovine epithelial and stromal cells of the endometrium were inoculated with Ureaplasma diversum, pathogenic strain 2312, at 10(6) or 10(3) color-changing units (ccu)/ml in the presence of 1% fetal bovine serum (depleted of steroids by dextran-charcoal treatment) to assess the effect of infection on prostaglandin biosynthesis . When the inoculum of U . diversum was 10(6) ccu/ml, the concentration of U . diversum in the culture medium decreased with time . U . diversum was found on the epithelial and stromal cell monolayers, increasing in titer 100-fold, indicating that attachment and eventually growth occurred . When the inoculum was 10(3) ccu/ml, the titer of U . diversum remained the same or increased in the supernatant and increased on epithelial and stromal cells . The effect of infection was evaluated by measurement of the primary prostaglandin produced by each cell type, prostaglandin F2a for epithelial cells and prostaglandin E2 for stromal cells . Infection with U . diversum significantly decreased prostaglandin F2a accumulation, by 44.7% +/- 6.0% at 10(6) ccu/ml (P < or = 0.005) and 15.8% +/- 5.3% at 10(3) ccu/ml (P < or = 0.05) in epithelial cells . Prostaglandin E2 accumulation by stromal cells was decreased by 34.0% +/- 4.0% at 10(6) ccu/ml (P < or = 0.001) and by 13.5% +/- 2.7% at 10(3) ccu/ml (P < or = 0.005) . Infection with 10(6) ccu/ml did not alter endometrial cell viability, as shown by protein measurement, trypan blue dye exclusion, and cell plating efficiency tests . Thus, alterations in prostaglandin production were not due to cell deterioration . These observations suggest that U . diversum can alter prostaglandin E2 and prostaglandin F2a patterns in primary cultures of bovine endometrial cells without affecting cell viability. Handchir Mikrochir Plast Chir, 1994 May, 26(3), 156 - 9 {Single dose prevention with cefuroxime in plastic surgery . Control of serum level, efficacy and tolerance}; Abel R et al.; Clinical efficacy and drug safety of single-shot prophylaxis with Cefuroxime was investigated in a series of 50 elective plastic surgical operations . Serum and tissue concentrations at one hour after application were determined in ten patients undergoing breast reduction . Levels far above the minimum inhibitory concentrations for possible pathogenic bacteria were obtained . No infection occurred . Wound complications not related to wound infection occurred in 12%. Handchir Mikrochir Plast Chir, 1994 May, 26(3), 150 - 5 {Preoperative prevention of infection with cefuroxime in hand surgery emergencies . Efficacy, control of concentration, follow-up}; Abel R et al.; Clinical efficacy and drug safety of Cefuroxime for preoperative prophylaxis of wound infection was investigated in 20 cases of acute open hand injuries . Ten minutes before filling of the tourniquet, Cefuroxime was given . Tissue and serum levels of ten patients were determined 10 and 70 minutes later . Levels far above the minimum inhibitory concentrations of possible pathogenic bacteria were obtained . No serious infection occurred . Wound complications not related to infection occurred in 15%. J Periodontol, 1994 May, 65(5 Suppl), 521 - 9 Neutrophil defects as risk factors for periodontal diseases; Hart TC et al.; There are several hypotheses proposed for the etiologic mechanisms causing periodontal diseases . These include a paradigm in which all individuals are equally susceptible to one or several pathogenic bacteria; a second paradigm that holds that all bacteria are equally virulent and that host susceptibility determines onset of disease; or a combination of the above . In this review, we analyze the role of neutrophil dysfunction as a risk factor for the onset of periodontitis . Both intrinsic or genetically inherited abnormalitie