Gene, 1991 Oct 30, 107(1), 75 - 82 Sequences of three genes specifying xylanases in Streptomyces lividans; Shareck F et al.; The entire nucleotide (nt) sequences of three genes (xlnA, xlnB and xlnC) of Streptomyces lividans encoding three distinct xylanases (Xln) have been determined . The nt sequences were confirmed by comparing the deduced amino acid (aa) sequences with the ones derived from the N-terminal aa sequences of the mature purified proteins . The N-terminus of the XlnA showed some homology with either the N-termini or the C-termini of eight other Xln and of two exo-glucanases . The N-terminus of XlnB is homologous to that of XlnC and to Xln of seven other microorganisms. Nature, 1991 Oct 17, 353(6345), 668 - 70 Activation of the NADPH oxidase involves the small GTP-binding protein p21rac1; Abo A et al.; Professional phagocytes, such as neutrophils and monocytes, have an NADPH oxidase that generates superoxide and other reduced oxygen species important in killing microorganisms . Several components of the oxidase complex have been identified as targets of genetic defects causing chronic granulomatous disease . The complex consists of an electron transport chain that has as its substrate cytosolic NADPH and which discharges superoxide into the cavity of the intracellular phagocytic vacuole . The only electron transport component identified so far is a low-potential cytochrome b, apparently the only membrane component required . At least three cytosolic factors are also necessary, two of which, p67phOx and p47phOx, have been identified by their absence in patients with chronic granulomatous disease . A third component, sigma 1, is required for stimulation of oxidase activity in a cell-free system . The active components of purified sigma 1 are two proteins that associate as heterodimers, and here we report that these are the small GTP-binding protein p21rac1 and the GDP-dissociation inhibitor rhoGDI. FEMS Microbiol Lett, 1991 Oct 15, 67(3), 261 - 5 Near on-line detection of enteric bacteria using lux recombinant bacteriophage; Kodikara CP et al.; The potential for a revolution in microbial testing can be perceived with the near on-line detection of indicator microorganisms . By definition, these are microorganisms present in significant numbers within a food which, while not pathogenic, can be related through increasing count to the increased probability of pathogen contamination . We have used recombinant lux+ bacteriophage to detect enteric indicator bacteria without recovery or enrichment in 50 min, provided that they are present at levels greater than 10(4) g-1 or cm-2 . After a 4-h enrichment, samples having enteric counts of 10 g-1 or cm-2 can be distinguished from background. Avian Dis, 1991 Oct-Dec, 35(4), 892 - 6 Comparison of a quantitative microtiter method, a quantitative automated method, and the plate-count method for determining microbial complement resistance; Lee MD et al.; A quantitative microtiter method for determining the degree of complement resistance or sensitivity of microorganisms is described . The microtiter method is compared with a quantitative automated system and the standard plate-count technique . Data were accumulated from 30 avian Escherichia coli isolates incubated at 35 C with either chicken plasma or heat-inactivated chicken plasma . Analysis of data generated by the automated system and plate-count techniques resulted in a classification of the microorganisms into three groups: those sensitive to the action of complement; those of intermediate sensitivity to the action of complement; and those resistant to the action of complement . Although the three methods studied did not agree absolutely, there were statistically significant correlations among them. Planta Med, 1991 Oct, 57(7), S36 - 43 The genetic and biochemical basis of polyketide metabolism in microorganisms and its role in drug discovery and development; Hutchinson CR et al.; The possibilities for the design of new drug screening and development strategies directed to a specific objective on the basis of genetic engineering of microorganisms is discussed from two points of view . Firstly, results of work on genetic hybrids of Streptomyces species for the production of new metabolites such as mederrhodin (1) and aloespanoarin II (4) are described . Secondly, the enhanced production of known metabolites such as tetracenomycin A2 (11) and tetracenomycin C (9) by recombinant Streptomyces species is considered . Mechanistic aspects of polyketide metabolism are included. Dig Dis Sci, 1991 Oct, 36(10), 1459 - 68 Short-chain fatty acids induce reversible injury of porcine colon; Argenzio RA et al.; Carbohydrate malabsorption frequently results in an increased net production of organic acids by colonic microorganisms and an acidification of colonic contents . Colonic structure and function during and following mucosal exposure to acetate at various H ion concentrations was examined under both in vivo and in vitro conditions . An acetic acid dose and time-dependent injury of the surface epithelium sequentially resulted in (1) degeneration and extrusion of enterocytes and increased ion permeability (pH 5.0); (2) formation of subepithelial blisters and increased mucosal permeability to mannitol (pH 4.0), and (3) sloughing of surface epithelium and the abolition of active NaCl absorption (pH 3.0) . Both acetate and lactate at pH 4.0 produced significantly greater injury than similarly acidified NaCl . Crypt cell structure and Cl secretory function were preserved, however, and migration of viable cells from adjacent crypts rapidly covered the denuded surface within 30-60 min of recovery . Normal structure and function were nearly restored in 2 hr . These results suggest that colonic mucosal injury is possible under conditions that may be present during carbohydrate malabsorption syndromes . They also provide evidence that the process of surface reepithelialization may be of central importance in the defense and repair of the colonic mucosa during such acid-induced injury. Infect Immun, 1991 Oct, 59(10), 3351 - 9 Effects of immunization with Porphyromonas gingivalis and Prevotella intermedia on progression of ligature-induced periodontitis in the nonhuman primate Macaca fascicularis; Ebersole JL et al.; The nonhuman primate (Nhp) has proven to be a useful model of human periodontitis . This study describes the immunological characteristics of this model and the ability of active immunization to interfere with ecological changes in the microbiota and its associated disease symptoms . Nhps were parenterally immunized with whole-cell antigens of Porphyromonas gingivalis and Prevotella intermedia . The immunization elicited an approximate 2-log increase in serum immunoglobulin G (IgG), IgM, and IgA isotype antibody that was highly specific for these immunogens . Postimmunization and postligation, there was minimal change in the levels of specific antibody . P . gingivalis immunization significantly inhibited the emergence of this species during disease progression . In contrast, induction of anti-P . intermedia antibody had a minimal effect on this species within the subgingival plaque . Plaque indices showed few changes that could be attributed to active immunization . Both bleeding on probing and loss of attachment were higher in ligated sites of immunized animals than in the placebo-treated group . A significant increase in bone density loss was observed in the ligated teeth from immunized versus control animals . These findings indicate that active immunization of Nhps can elicit a substantial systemic immune response; however, while this response may effect the emergence of an individual microorganism, it appears that other ecological considerations are critical in disease progression . It is also possible that the induction of a broad-based immune response to multiple bacterial antigens can result in increased disease, potentially associated with hypersensitivity reactions to the bacteria in the subgingival plaque. Pediatr Clin North Am, 1991 Oct, 38(5), 1183 - 207 Periodontal health and disease in children and adolescents; Bimstein E; The prevention and treatment of periodontal diseases in children and adolescents are most desirable and the physician should be involved in the achievement of these goals . Furthermore, cooperation between the physician and the dentist may be imperative for the comprehensive treatment of some patients . One should be aware of the influence of the general growth and development of the periodontium in order to be able to differentiate between health and disease . Periodontal diseases in children and adolescents include chronic gingivitis, gingival recession, chronic periodontitis, prepubertal periodontitis, juvenile periodontitis, and cases with peculiar causes . The main cause for periodontal diseases is the microorganisms in the dental plaque . In addition, the systemic status of the individual may affect the response of the periodontal tissues and vice versa . The physician and dentist should cooperate with the purpose of providing comprehensive prevention, diagnosis, and treatment of periodontal diseases and systemic diseases. Endod Dent Traumatol, 1991 Oct, 7(5), 226 - 9 Scanning electron microscopy of bacteria in the apical part of root canals in permanent teeth with periapical lesions; Molven O et al.; The most apical 2 mm of the root canals of periapically diseased roots were examined for microorganisms by scanning electron microscopy (SEM) . Bacteria in this area were observed in 10 out of 12 (83.3%) cases . The two remaining cases exhibited bacteria more coronally, with tissue remnants between the bacterial front and the apical foramen . Rod-shaped bacteria dominated, but filaments, spirochetes and cocci were also seen . Cocci and rods sometimes formed micro-colonies . Occasionally, cocci were seen attached to filaments forming "corn-cob"-like structures . Deposits resembling bacterial plaque were also found inside the root canal . SEM is useful for studying microbial topography of the apical root canal. Antonie Van Leeuwenhoek, 1991 Oct-Nov, 60(3-4), 175 - 91 Quantitative aspects of cellular turnover; Koch AL; Living organisms do not just grow by synthesizing cellular components . As part of the necessary steps for existence, some components are degraded after synthesis . Even for bacteria in balanced, exponential growth some substances, under some conditions, are turned over . In other phases of growth turnover can be much more extensive, but it is still selective . This review covers studies with animals as a way to put the studies on microorganisms in perspective . The history, the mathematics, and experimental design of turnover experiments are reviewed . The important conclusion is that most of the proteins during balanced growth are very stable in bacteria, although ribosomal proteins are degraded under starvation conditions . Another generalization is that the process of wall enlargement in general is associated with obligatory turnover of the peptidoglycan. Histol Histopathol, 1991 Oct, 6(4), 485 - 9 Chronic gastritis associated with Helicobacter pylori . Correlation between histological and bacteriological findings; Paz-Bouza JI et al.; Biopsy specimens of gastric and duodenal mucosa from 326 patients were examined bacteriologically and histologically to determine the correlation between chronic gastritis and H . pylori colonization . H . pylori was identified in 111 (66.5%) patients with evidence of chronic gastritis and in 97 (82.2%) individuals who had gastritis associated with other pathology (gastric o duodenal ulcer, carcinoma o bulboduodenitis) . The spiral bacteria was found more frequently in specimens with chronic superficial gastritis (88/107) and no significant difference was observed between the grade of activity of gastritis and H . pylori colonization . Giemsa stain was the most suitable method for detecting H . pylori in histological sections . By electron microscopy the microorganism was seen on the surface of the gastric mucosa, beneath the mucous layer, and more occasionally in intercellular junctions and the gastric pit. Arzneimittelforschung, 1991 Oct, 41(10), 1076 - 81 Toxicity of Echinacea purpurea . Acute, subacute and genotoxicity studies; Mengs U et al.; Single oral or intravenous doses of the expressed juice of Echinacea purpurea (EP) proved virtually non-toxic to rats and mice . After 4 weeks of oral administration in doses amounting to many times the human therapeutic dose laboratory tests and necropsy findings gave no evidence of any toxic effects in rats . Tests for mutagenicity carried out in microorganisms and mammalian cells in vitro and in mice all gave negative results . In an in vitro carcinogenicity study EP did not produce malignant transformation in hamster embryo cells. Arch Tierernahr, 1991 Oct, 41(7-8), 665 - 74 {ATP in the metabolism of ruminants}; Bergner H; The ATP yield from the carbohydrates of anaerobically living microorganisms in the rumen amounts to only 5-10% of the ATP yield of the intermediary metabolism in the presence of oxygen . Vital functions and thus microbial protein synthesis are due to protein degradation in the rumen . The ATP yield in the intermediary metabolism of ruminants is mainly achieved from propionate and microbial protein by means of gluconeogenesis because the absorption of glucose from digested starch is very low . The relationships between ATP yield in the rumen and the processes of glucose provision for the production of lactose as well as the protein content of the milk are shown . As important processes of ATP production in microorganisms from easily soluble carbohydrates take place in silage preparations before feed intake, the corresponding consequences for the metabolism of high-performance cows fed with silage are shown. Thorac Cardiovasc Surg, 1991 Oct, 39(5), 284 - 8 Early surgery for active infective endocarditis improves early and late results; Bogers AJ et al.; To investigate the timing of surgery in active infective endocarditis, the data of 54 patients, consecutively operated for this reason from September 1973 to May 1989, were analysed . Native valves were involved in 31 patients (57%): the aortic valve in 22, the mitral valve in 6, and both valves in 3 cases . Prosthetic valves were involved in 23 patients (43%): the aortic valve in 14, the mitral valve in 7, and both valves in 2 cases . There were no significant differences between involvement of native or prosthetic valves and mortality, morbidity, or consequences of morbidity . No significant correlation was found between causative microorganism and mortality, morbidity, or consequences of morbidity . The indication for operation was cardiac failure in 15 patients (28%), ongoing infection in 24 (44%) or a combination of these in 15 (28%) . Major embolization occurred in 12 patients (22%) and affected women more than men (p = 0.05) . Hospital mortality was 8 (15%) . Morbidity involved 15 more patients; structural deterioration of the valve prosthesis occurred in 1 patient; nonstructural dysfunction of the valve prosthesis occurred 11 times in 10 patients; anticoagulation-related hemorrhage involved 2 patients (1 with nonstructural dysfunction of the valve prosthesis); endocarditis was diagnosed in 3 patients . The consequences of these morbid events concerned 14 patients; reoperations were done 9 times in 8 patients; mortality was valve related in 6 cases . Because 2 more patients died during the course of the study, total late mortality was 8 . Probability of survival 5 years after operation was 72% (95% cl 56-83) and at 10 years 47% (95% cl 21-70).(ABSTRACT TRUNCATED AT 250 WORDS) Harefuah, 1991 Oct, 121(7-8), 232 - 5 {Bacterial tracheitis in children}; Sofer S et al.; Bacterial tracheitis (BT) was found in 10 of 748 children (1.3%) admitted with croup during 1983-1990 . 9.9% of all the 748 croup cases seen (74) were admitted to the pediatric intensive care unit (PICU) and 16 of the 74 required intubation . 10 of those intubated (62.5%) were found to have BT and had typical features of croup, including inspiratory stridor, hoarseness and cough . Airway obstruction resulted mainly from accumulated tracheal pus . After endotracheal intubation all required frequent suctioning of thick purulent secretions . In 2 children causative microorganisms were cultured from the blood, and in all 10 from the tracheal pus . All children were given antibiotic therapy but a 7 month-old girl died of secondary complications (respiratory syncytial virus infection, pneumonia and adult respiratory distress syndrome) . The others recovered and were discharged from the PICU within 3-14 days . BT should be suspected when tracheal intubation is required in croup . In such cases close monitoring in a PICU and frequent tracheal suctioning after intubation is necessary; antibiotic therapy should be considered. Bol Med Hosp Infant Mex, 1991 Oct, 48(10), 743 - 8 {Helicobacter pylori: can it be a contributing factor in peptic ulcer in childhood?}; Tovar-Calderon S et al.; Helicobacter pylori is a recently identified microorganisms which is thought to be the causing agent of the peptic acid disease in children as well as in adults . It is currently accepted that frequent relapses of this illness in spite of an adequate treatment can be associated to the faulty eradication of this bacteria . This article outlines the characteristics of H . pylori, its incidence, pathogenesis, as well as the current diagnostic methods used and the treatment applied. Appl Environ Microbiol, 1991 Oct, 57(10), 3049 - 51 Kinetics of Saccharomyces cerevisiae elimination from the intestines of human volunteers and effect of this yeast on resistance to microbial colonization in gnotobiotic mice; Pecquet S et al.; When healthy volunteers were given a daily dose of 3 x 10(8) life-dehydrated Saccharomyces cerevisiae cells for 5 days, the volunteers excreted 10(5) living yeast cells per g of feces at first, but the yeast cells disappeared within 5 days of the end of treatment . In gnotobiotic mice, S . cerevisiae administered alone colonized the intestinal tract but did not interfere with previous or subsequent colonization by a variety of potentially enteropathogenic microorganisms . When these microorganisms were present, the intestinal counts of S . cerevisiae were greatly reduced. Appl Environ Microbiol, 1991 Oct, 57(10), 2858 - 63 Degradation of organochlorine compounds in spent sulfite bleach plant effluents by actinomycetes; Winter B et al.; Actinomycetes isolated from different soil samples were tested for their abilities to utilize spent sulfite bleach effluents from a paper mill . Degradation and dechlorination of the chlorinated compounds in the effluents of the first two bleaching stages, i.e., chlorination stage {(C + D)red.} and alkaline extraction stage (E1O), were monitored by determining total organic carbon (TOC) and activated-carbon-adsorbable organic-bound halogen (AOX) . The isolates showed increased degradation rates after repeated incubations in the effluent-containing medium . Separation of the culture supernatants by ultrafiltration into three fractions of different molecular weights revealed substantial AOX and TOC reductions in the low-molecular-weight fraction . The AOX values of the higher-molecular-weight fractions were also reduced . Extracellular peroxidase and cell wall-bound catalase activities were produced during growth of the microorganisms on bleach effluents. Vet Microbiol, 1991 Oct, 29(2), 135 - 45 Survival of Dermatophilus congolensis in tropical clay soils submitted to different water potentials; Martinez D et al.; The survival of a rifampicin-resistant mutant of Dermatophilus congolensis in vertisol and oxisol soils from Guadeloupe and in their constitutive clays was studied using a pneumatic device for controlling water potentials (pF) . Experiments were carried out at two pF values simulating the wet season and the dry season . Survival time depended on the type of soil and its water content . Organic matter had a protective effect on the microorganism in oxisol but not in vertisol . The pathogenicity of D . congolensis was preserved in the soils which could therefore act as temporary reservoirs of this pathogen . Long-term survival of this organism in soils mixed with water suggests that ponds and dipping tanks may constitute sources of infection for cattle. Genitourin Med, 1991 Oct, 67(5), 403 - 7 Ultrastructural aspects of infection with Treponema pallidum subspecies pertenue (Pariaman strain); Engelkens HJ et al.; OBJECTIVE--To study ultrastructural aspects of infection with Treponema pertenue (Pariaman strain), originating from West Sumatra, Indonesia . MATERIALS AND METHODS--Biopsy material originating from skin lesions in ten young children suffering from early infectious yaws in Indonesia, and rabbit testicular tissue inoculated with T pertenue . Human skin as well as rabbit testicular tissue was examined by means of conventional electron microscopy . RESULTS--In human skin, treponemes were found in interepidermal spaces in 5 out of 10 specimens . In two of five positive specimens, treponemes were also seen in the dermis . In one out of five specimens from rabbit testicular tissue a profusion of treponemes was found lying in the interstitial myxomatous tissue . Microorganisms showed no adhesion to fibroblasts . CONCLUSION--This ultrastructural study of T pertenue demonstrated the scarcity and focal distribution of treponemes in tissue and did not reveal any morphological differences from the Gauthier strain of T pertenue . No differences from the ultrastructure of T pallidum were observed either. Genetics, 1991 Oct, 129(2), 399 - 407 Geographic distribution and inheritance of three cytoplasmic incompatibility types in Drosophila simulans; Montchamp-Moreau C et al.; Wolbachia-like microorganisms have been implicated in unidirectional cytoplasmic incompatibility between strains of Drosophila simulans . Reduced egg eclosion occurs when females from uninfected strains (type W) are crossed with males from infected strains (type R) . Here we characterize a third incompatibility type (type S) which is also correlated with the presence of Wolbachia-like microorganisms . Despite the fact that the symbionts cannot be morphologically distinguished, we observed complete bidirectional incompatibility between R and S strains . This indicates that the determinants of incompatibility are different in the two infected types . S/W incompatibility is unidirectional and similar to R/W incompatibility . A worldwide survey of D . simulans strains showed that type S incompatibility was found only in insular populations which harbor the mitochondrial type SiI . Both W and R types were found among mainland and island populations harboring the worldwide mitochondrial type SiII . Type S incompatibility could be involved in the reinforcement of the geographical isolation of SiI populations. Jpn J Med Sci Biol, 1991 Oct-Dec, 44(5-6), 213 - 24 Demonstration of acid phosphatase activity in antigenic glycoprotein fractions obtained from the culture filtrate of Pseudomonas pseudomallei; Kondo E et al.; Pseudomonas pseudomallei, the causative microorganism of melioidosis, was grown in Mueller-Hinton liquid medium, and glycoprotein fractions were separated from the culture filtrate by ammonium sulfate precipitation, gel-filtration with Sephadex G-75, and column chromatography with DEAE-cellulose . The fractions revealed acid phosphatase activity, and reacted to the sera from melioidosis patient in gel-diffusion precipitation assay. Immun Infekt, 1991 Oct, 19(5), 143 - 52 {Systematics, differentiation, and detection of bacterial infections-- the family Mycobacteriaceae}; Bottger EC; Comparative 16S rRNA sequencing allows to infer natural relationships among bacteria, to characterize and identify microorganisms at a molecular level and to develop DNA probes specific at any desired taxonomic level (e.g . family, genus, species) . Probes targeted at ribosomal RNA are suitable for in situ hybridization of whole, intact bacterial cells as well as in polymerase-chain-reaction techniques for sensitive detection and identification of bacteria . Comparative 16S rRNA sequencing provided the basis for a systematic phylogenetic analysis of the genus Mycobacterium . Certain growth characteristics, i.e . thermotolerance and growth rate correspond to natural relationships among the mycobacteria . However, the phylogenetic relatedness within the slow-growing species did not reflect the Runyon classification of photochromogenic, scotochromogenic and nonphotochromogenic mycobacteria . The use of oligonucleotides targeted at highly or semi-conserved regions within the 16S rRNA molecule allows a universal procedure for amplification and rapid sequence determination of 16S rDNA-gene fragments from any virtually bacterial organism . This method of amplification of 16S rDNA-gene fragments was used to identify a novel, uncultured pathogen and opens new perspectives for other infectious diseases of unknown cause. Hautarzt, 1991 Oct, 42(10), 613 - 6 {Serotyping of Chlamydia trachomatis isolates}; Naher H et al.; Antigens can be used in the classification of microorganisms and can give information about the biological behaviour of the infectious agent and the spread of the infection . Starting with the mouse toxicity prevention test, followed by the two-step and then the one-step micro-IFT using polyclonal antibodies, C . trachomatis serovars are now typed with monoclonal antibodies . Worldwide, serovars D, E and F are found with the highest prevalence . No differences have been found between women and men in the prevalence of serovars . In addition, symptomatic and asymptomatic courses of the disease were not correlated with distinct serovars . The persisting technical difficulties of for large-scale typing could be overcome by the use of the polymerase chain reaction followed by treatment with endonucleases. J Immunol, 1991 Oct 1, 147(7), 2240 - 7 Characterization of a Trypanosoma cruzi C3 binding protein with functional and genetic similarities to the human complement regulatory protein, decay-accelerating factor; Norris KA et al.; Evasion of the complement system by microorganisms is an essential event in the establishment of infection . In the case of Trypanosoma cruzi, the causative agent of Chagas disease, resistance to complement-mediated lysis is a developmentally regulated characteristic . Infectious trypomastigotes are resistant to complement-mediated lysis in the absence of immune antibodies, whereas the insect forms (epimastigotes) are sensitive to lysis via the alternative complement pathway . We have purified a developmentally regulated, trypomastigote glycoprotein, gp160, and shown that it has complement regulatory activity . The T . cruzi gp160 restricts complement activation by binding the complement component C3b and inhibiting C3 convertase formation . The protein is anchored in the parasite membrane via a glycosyl phosphatidylinositol linkage, similar to the human complement regulatory protein, decay-accelerating factor . Using anti-gp160 antibodies we have isolated a bacteriophage lgt11 clone expressing a portion of the gp160 gene that shares significant DNA sequence homology with the human DAF gene . These results provide functional, biochemical, and genetic evidence that the T . cruzi gp160 is a member of the C3/C4 binding family of complement regulatory proteins, and that gp160 may provide the infectious trypomastigotes with a means of evading the destructive effects of complement. West J Med, 1991 Oct, 155(4), 365 - 9 Mechanisms and consequences of leukocyte-endothelial interaction; Harlan JM et al.; Leukocyte adhesion to endothelium is a critical event in host defense against microorganisms and in the repair of tissue damage . Under some circumstances, however, altered leukocyte-endothelial interactions may contribute to the pathogenesis of inflammatory and immune diseases . In a number of experimental models, the inhibition of leukocyte adherence to endothelium substantially reduces vascular and tissue injury . Antiadhesion therapy may represent a novel approach to the treatment of a wide spectrum of clinical disorders. Virology, 1991 Oct, 184(2), 773 - 6 Internal initiation and frameshifting in infectious bursal disease virus sequence expressed in Escherichia coli; Macreadie IG et al.; As part of our efforts to produce native molecules of the host protective antigen (VP2) of infectious bursal disease virus (IBDV) in microorganisms, we have restored nucleotide sequences encoding the VP2 N-terminus which were not present in the original clone . In addition to this process, we produced constructs that contained +5, +4, -1, and -2 frameshifts that still allowed expression of the IBDV polyprotein, VP2 and VP3 . The size of translation products and examination of the nucleotide sequence lead us to speculate that both +1 frameshifting and internal initiation events lead to the synthesis of IBDV proteins in Escherichia coli. Am J Med, 1991 Sep 30, 91(3C), 2S - 13S Oxidants and antioxidants: state of the art; Bast A et al.; Reactive oxygen species are regarded as merely pernicious . This is incorrect for they play a pivotal role in many physiologic reactions, such as cytochrome P450-mediated oxidations, regulation of the tone of smooth muscle, and killing of microorganisms . An imbalance in oxidant-antioxidant activity is involved in many free radical-mediated pathologies, e.g., ischemia-reperfusion and asthma . In an attempt to alleviate these pathologies with antioxidants, it should be noted that these compounds are neither specific nor mere antioxidants . Associated with antioxidant activity is a pro-oxidant action . In the development of new antioxidant therapies, the important question of how these drugs are incorporated in or commensurate with existing integrated physiologic radical-defense systems should be addressed. Schweiz Med Wochenschr, 1991 Sep 28, 121(39), 1419 - 22 {Prosthesis infections: is ambulatory conservative therapy possible?}; Zimmerli W et al.; Infections associated with prosthetic devices involve an increased risk of persistence or relapse if the foreign body is not removed . Clinical and experimental observations indicate a lack of correlation between the minimal bactericidal concentration of a drug and its efficacy in device-related infections . Alternative in-vitro tests indicate that the efficacy of a drug experimental implant-associated infections depends on its activity on non-growing and adhering microorganisms . These data have been evaluated in a clinical pilot study . 12 patients with orthopedic device-related infections were treated with rifampin-containing regimens because this drug has excellent activity on adherent microorganisms . The success rate was 83% during a follow-up period of 2 years or until the removal of the device . Nevertheless, before considering conservative treatment of device-related infections, controlled clinical studies are needed which confirm the experimental results. Schweiz Med Wochenschr, 1991 Sep 28, 121(39), 1423 - 8 {Progress and problems in hospital infections: exemplified by pneumonia}; Francioli P et al.; Nosocomial pneumonias have various etiologies and their development depends mainly on the underlying condition of the patients . Intubated patients are prone to development of bacterial pneumonia from the oropharyngeal or gastric flora . Prevention relies on reducing exogenous as well as endogenous colonization of the bronchotracheal tree: avoidance of cross-contamination, maintenance of a physiological gastric pH and, possibly, selective digestive decontamination . Neutropenic patients may develop invasive aspergillus infection . Prevention depends on appropriate air filtration . Patients with cellular immunodeficiency are susceptible to various agents . Prevention of legionella depends on control of the water and ventilation systems . The prevention of cytomegalovirus infection includes the screening of blood products for certain patients and, in some cases, the administration of hyperimmune gammaglobulins and possibly ganciclovir . Even though Pneumocystis carinii pneumonia is thought to be due to reactivation, recent evidence suggests that transmission may occur between patients and therefore appropriate respiratory isolation is advisable . Finally, nosocomial tuberculosis is an increasing problem in which control depends on early diagnosis and treatment of patients as well as on appropriate air exchange in particular rooms of the hospital . In conclusion, the prevention of nosocomial pneumonia includes numerous measures which largely depend on the type of microorganisms. Arch Androl, 1991 Sep-Oct, 27(2), 117 - 26 Electron microscopy of Chlamydia trachomatis infection of the male genital tract; Villegas H et al.; Semen specimens and testicular and epididymis biopsy from a patient of an infertile marriage were examined by transmission electron microscopy . Intraepithelial vesicles containing C . trachomatis were present in remaining cytoplasmic droplets in spermatozoa, desquamated epithelial cells, and stereocilia from epididymis . Elementary bodies were demonstrated in connective tissue from testes and in Leydig cells . The association between the microorganisms and spermatozoa contribute to the decreased motility and necrospermia . The morphologic alterations in epididymis are responsible for decreased sperm maturation . The damage to Leydig cells can be demonstrated only by electron microscopy. Ann Plast Surg, 1991 Sep, 27(3), 216 - 20 In vitro adhesion of endogenous skin microorganisms to breast prostheses; Jennings DA et al.; Bacterial proliferation on polymeric biomaterials varies with the material and microorganism . Subclinical infection is implicated frequently as the initiative factor in capsular contracture around breast prostheses . The ability of endogenous skin microorganisms to produce an exopolysaccharide "slime" is emerging as an important factor in biomaterial colonization . This study was designed to demonstrate the ability of microorganisms of varying slime productivity to colonize, in vitro, different kinds of breast prostheses . Six-millimeter disks from seven kinds of silicone prostheses and polyurethane foam were exposed to three radioactivity labeled strains of bacteria, one slime producer, and two non-slime producers, for 1 hour . Data were expressed as colony-forming units bound per disk . There was no significant difference in adherence between the bacterial strains used, suggesting that initial adherence was nonspecific . The adherence did not appear to be related to surface type, whether smooth or textured, nor to the polymeric composition of the implant material, whether silicone or polyurethane, nor to the presence or absence of slime . Also, adherence was consistent with expected nonspecific bacterial adherence to biomaterials. Postgrad Med J, 1991 Sep, 67(791), 846 - 7 Spiral shaped microorganisms in the human duodenal mucosa; Nakshabendi IM et al.; A new spiral shaped microorganism, Gastrospirillum hominis, distinct from Helicobacter pylori, has recently been described in the gastric mucosa . We report a patient with duodenal erosions who was found to have these organisms in his duodenal mucosa . This bacterium is not necessarily specific to the stomach, and its association with peptic damage needs to be studied further. Med Res Rev, 1991 Sep, 11(5), 473 - 501 Use of microorganisms for the study of drug metabolism: an update; Clark AM et al.; The use of microorganisms as tools in the study of drug metabolism appears to be gaining popularity . The selected examples cited here provide additional evidence of the utility of these systems as alternative in vitro models for studying drug metabolism in humans . However, as was noted earlier, this model, nor any other in vitro model system could ever replace animals in biomedical research . However, it is apparent from the numerous examples cited here and in the previous review of this area that microorganisms are a reliable, reproducible alternative to small animals as predictive models in drug metabolism studies . The continuing development of techniques that reduce the use of animals in research is encouraged and this procedure appears to be gaining more widespread acceptance for such use. Biotechniques . 1991 Sep;11(3):318, 320, 322. Immunocytochemical labeling of chitin in the cell walls of zoopathogenic fungi; Walker AN et al.; Chitin is a complex polysaccharide composed of repeating units of beta-1,4-N-acetyl-D-glucosamine . It is found in many invertebrates, in some algae, in the cyst form of several protozoans and in the cell walls of most fungi . Chitin, however, is not expressed in vertebrate tissues . We used a polyclonal rabbit antiserum against macromolecular chitin to label and stain by immunoperoxidase technique in formalin-fixed, paraffin-embedded tissues a variety of zoopathogenic fungi . The antiserum bound to the cell walls of the microorganisms, but not to (mammalian) host tissue elements. Rev Prat, 1991 Sep 1, 41(19), 1785 - 8 {Infected aneurysms of the aorta}; Raffi F et al.; Mycotic aneurysms, a quite rare syndrome, are classified into three groups: primary (the most frequent one), secondary to bacterial endocarditis, and secondary to direct inoculation (infections focus or trauma) . Primary aneurysms are related to bacteremia with bacterial setting of an atheromatous lesion, most often . Clinical presentation is often misleading or delayed from infectious process . However, presence of clinical aneurysm, pain, and infectious syndrome should suggest diagnosis and lead to immediate antibiotic therapy and rapid surgical management, as rupture of the aneurysm is a frequent, serious and ineluctable complication . Importance of microbiologic search is to be emphasized as the diversity of the responsible microorganisms is very high; waiting for bacteriological results, a bactericidal double antibiotherapy should be instituted. Gastroenterol Clin North Am, 1991 Sep, 20(3), 531 - 47 Structure and function of intestinal M cells; Trier JS; M cells are structurally distinctive, uniquely permeable epithelial cells found only overlying the domes of mucosal lymphoid follicles . Antigenic macromolecules and some viruses, bacteria, and protozoa enter their apical surface by endocytosis or phagocytosis . These substances traverse the M-cell cytoplasm by transcytosis, breaching the epithelial barrier, and then interact with the subepithelial immunocompetent cells to initiate mucosal and systemic immune responses . The M cell serves as a portal of entry for selected pathogens that cause disease locally in the wall of the intestine or, following dissemination, at distant sites . The mechanisms that regulate adherence to and penetration of M cells by macromolecules and microorganisms are not known, but selective binding of secretory IgA to the luminal surface may be important . Whether M cells simply serve a sieving function and always transport substances unchanged across the epithelial barrier or whether they also sort and process antigens they endocytose and present them to adjacent lymphoid cells requires further study. Infect Immun, 1991 Sep, 59(9), 3267 - 72 Lethal effects of Actinobacillus actinomycetemcomitans leukotoxin on human T lymphocytes; Mangan DF et al.; The majority of strains of Actinobacillus actinomycetemcomitans isolated from patients with periodontal diseases secrete a leukotoxin that destroys human myeloid cells within minutes but has no effect on viability of peripheral blood lymphocytes in culture for 1.5 h . However, since this organism persists in the gingival crevice and thus may continuously release toxin over extended periods of time, we assessed the viability of T cells cultured with leukotoxin (0 to 250 ng/ml) for up to 2 days . Although the total numbers of cells recovered from cultures with or without leukotoxin were equivalent, leukotoxin killed up to 70% of the T cells in a time- and concentration-dependent manner . Cell death was associated with uptake of propidium iodide, release of 51Cr from the cytoplasm, and morphological evidence of damage to the plasma membrane and apoptosis . Leukotoxin also induced increased cleavage of chromosomal DNA into nucleosome-sized fragments, suggesting activation of an endogenous nuclease in the T cells . These data suggest that leukotoxin kills T cells by pathways resembling necrosis and programmed cell death . Leukotoxin-induced lymphotoxicity may represent a critical mechanism by which A . actinomycetemcomitans suppresses the host local immune response and contributes to the pathogenesis of diseases involving this microorganisms. Obstet Gynecol, 1991 Sep, 78(3 Pt 2), 503 - 5 Eikenella corrodens chorioamnionitis; Jeppson KG et al.; Eikenella corrodens was once considered a microorganism of little clinical consequence . But over the past decade, there has been a marked increase in the number of reports of serious infections caused by this organism . We present a case of E corrodens chorioamnionitis in a patient with intact membranes . This is the second known case of its kind to be reported in the medical literature . The true incidence of obstetric and gynecologic infections may be much higher than reported because of the organism's susceptibility to routine antibiotic regimens and the failure of some strains to exhibit characteristic colony morphology on solid agar. Rev Chil Pediatr, 1991 Sep-Oct, 62(5), 321 - 2 {Etiology of vulvovaginitis in childhood}; Romero P et al.; A prospective study on the causal microorganism of vulvovaginitis was done to 100 ambulatory patients seen at a pediatric gynecology unit of a metropolitan hospital at Santiago, Chile, from november 1988 throughout july 1989 . Samples of vaginal discharge were taken from each patient and studied for bacteria, fungi and trichomonas . Search of pinworms was also done in 55 patients by the transparent adhesive tape test . It was possible to confirm the etiology of vulvovaginitis in 81 cases . Bacteria were isolated in 68 of them, fungi in 4, Trichomonas vaginalis in one patient and pinworms in 8. Pediatr Dent, 1991 Sep-Oct, 13(5), 267 - 72 Serum antibody levels to oral microorganisms in children and young adults with relation to the severity of gingival disease; Bimstein E et al.; The purpose of this study was to describe and compare the IgG and IgM serum antibody levels to 10 microorganisms involved in periodontal diseases in children and young adults with no systemic disease, but with either minimal/none or severe gingival inflammation . Blood samples from 15 children and 14 young adults were collected . Seven children and nine adults had minimal or no gingival inflammation; the rest had severe gingivitis . Kruskal-Wallis H analysis indicated significant differences among the age groups in the IgM values for all microorganisms and for most organisms in the IgG values . The contrast coefficient matrix values between children and young adults were significant for all the microorganisms for the IgM values and for most of the organisms for the IgG values when the severity of the disease was not taken into consideration . However, when the severity of the disease was also considered, the contrast coefficient matrix values for most of the microorganisms were not significant for both the IgG and IgM values . Age had a more significant influence on the serum antibody levels than the severity of the disease, mostly in the IgM values. Tsitol Genet, 1991 Sep-Oct, 25(5), 15 - 20 {Use of the DNA-specific fluorochrome olivomycin for work with cell cultures}; Mikhailova GR et al.; A high-sensitive, easy and rapid proximate method has been developed to reveal mycoplasmas in the monolayer cell cultures using home fluorescent antibiotic olivomycin . This method has been used to screen many cell lines with its high effectiveness being shown . As based on this method the following control methods are worked out: indication of mycoplasmas in animal blood sera, used for the cultivation of cell lines detection of contaminant microorganisms of the cell cultures (fungi and bacteria) and human ureaplasmas. Pharm Res, 1991 Sep, 8(9), 1079 - 86 Liposomes and nanoparticles in the treatment of intracellular bacterial infections; Couvreur P et al.; The treatment of infections caused by obligate or facultative intracellular microorganisms is difficult because most of the available antibiotics have either poor intracellular diffusion and retention or reduced activity at the acidic pH of the lysosomes . The need for antibiotics with greater intracellular efficacy led to the development of endocytosable drug carriers, such as liposomes and nanoparticles, which mimic the entry path of the bacteria by penetrating the cells into phagosomes or lysosomes . This Review assesses the potential of liposomes and nanoparticles in the targeted antibiotic therapy of intracellular bacterial infections and diseases and the pharmaceutical advantages and limitations of these submicron delivery systems. J Dairy Sci, 1991 Sep, 74(9), 3035 - 46 Synthesis and biohydrogenation of fatty acids by ruminal microorganisms in vitro; Wu Z et al.; Ruminal degradation, synthesis, and biohydrogenation of fatty acids were examined in vitro . Diets were incubated with ruminal contents, and changes of fatty acids were measured . Two fat supplements, a calcium soap and an animal-vegetable blend, were included in diets at various levels . Addition to diets of acetate and isoacids (collective term for certain short-chain acids) also were tested for effects on fatty acid synthesis . Overall, 6.6 mg of fatty acids/g of fat-free diet were synthesized during 24-h incubation regardless of supplementations . Fatty acids synthesized in greatest amounts were odd-numbered or branched chains, whereas chains of 16 and 18 carbons changed little, and chains shorter than 14 carbons decreased . Degradation of {1-14C}palmitic acid was negligible, as determined by recovery of the label in CO2 (.03%) and acetate (1.09%) after 4-h incubation with rumen contents . Biohydrogenation of fatty acids averaged 47% in diets containing calcium soap and 71% with animal-vegetable blend . Synthesis and biohydrogenation were similar to those measured previously in vivo, showing that in vitro measurements reliably predicted metabolism of fatty acids in vivo. J Dairy Sci, 1991 Sep, 74(9), 3025 - 34 Ruminal synthesis, biohydrogenation, and digestibility of fatty acids by dairy cows; Wu Z et al.; Ruminal synthesis and biohydrogenation of fatty acids in dairy cows were determined by sampling duodenal digesta through T-cannulas . Fatty acid digestibility in the total tract also was measured . Five diets (concentrate:alfalfa hay:alfalfa haylage:corn silage, 2:1:1:1, DM) in a 5 x 5 Latin square contained either no added fat; 3 or 6% added calcium soap; or 3 or 6% animal-vegetable blend fat . Seventy percent of dietary fatty acids were recovered at the duodenum, and 106 g/d were synthesized in the rumen regardless of diets . Fatty acids synthesized in greatest amounts were odd or branched chains, whereas more than 90% of the fatty acids shorter than 14 carbons disappeared . Fatty acids in calcium soap were biohydrogenated 57% and in animal-vegetable blend 87% . Fatty acids in calcium soap were more digestible (80.0 vs . 75.7%) than those in the blended fat due to greater unsaturation in the small intestine . Ruminal microorganisms selectively synthesized fatty acids. J Clin Microbiol, 1991 Sep, 29(9), 2024 - 9 Cross-reacting antigens between Neorickettsia helminthoeca and Ehrlichia species, shown by immunofluorescence and Western immunoblotting; Rikihisa Y; Dogs orally infected with Neorickettsia helminthoeca developed immunoglobulin G titers against Erlichia risticii, Erlichia sennetsu, and Erlichia canis similar to those against N . helminthoeca antigen, as determined by immunofluorescence . Western immunoblotting showed that the major common antigens shared among the microorganisms were 80- or 78-kDa and 64-kDa polypeptides . In contrast, horse anti-E . risticii and anti-E . sennetsu and dog anti-E . canis sera reacted more weakly to N . helminthoeca antigen than to homologous antigens in both immunofluorescence and Western immunoblotting . Antisera raised in other species of animals, i.e., mouse anti-E . canis and rabbit anti-E . risticii and anti-E . sennetsu sera, however, all reacted with the 64-kDa antigen of N . helminthoeca . This strong antigenic cross-reactivity and similarity in Western immunoblotting reaction profiles indicate that N . helminthoeca is antigenically closely related to E . risticii and E . sennetsu and less so to E . canis . In both immunofluorescence and Western immunoblotting, E . canis shared fewer common antigens with E . risticii and E . sennetsu than N . helminthoeca did . It is reasonable to conclude that these results may have both diagnostic and taxonomic significance. Appl Environ Microbiol, 1991 Sep, 57(9), 2645 - 50 Amplification, cloning, and sequencing of a nifH segment from aquatic microorganisms and natural communities; Kirshtein JD et al.; By use of the polymerase chain reaction and degenerate oligonucleotide primers for highly conserved regions of nifH, a segment of nifH DNA was amplified from several aquatic microorganisms, including an N2-fixing bacterium closely associated with the marine filamentous cyanobacterium Trichodesmium sp., a heterotrophic isolate from the root/rhizome of the seagrass Ruppia maritima, and the heterocystous freshwater cyanobacterium Anabaena oscillarioides . nifH segments were amplified directly from DNA extracted from the rhizosphere of roots of the seagrass Halodule wrightii . The nifH fragments were then cloned and sequenced . The DNA and deduced amino acid sequences were compared with known sequences, revealing distinct differences between taxonomic groups . This technique was shown to be useful for (i) the detection of N2-fixing microorganisms and (ii) rapidly obtaining the DNA sequence of the nifH gene, which provides information about general taxonomic groups of N2-fixing microorganisms. Optom Vis Sci, 1991 Sep, 68(9), 718 - 20 Efficacy of chlorine disinfection of soft contact lenses; Ferreira JT et al.; We evaluated the chlorine system SOFTAB (Alcon) for the disinfection of soft contact lenses . The results indicate that a 1000-fold reduction in microorganisms was achieved within 6 h . Even with the slight interference of residual cleaner and the more significant interference of organic matter disinfection was still achieved. Immunol Today, 1991 Sep, 12(9), 327 - 31 Complement evasion strategies of microorganisms; Cooper NR; The success of microorganisms as human pathogens stems partly from their ability to evade recognition and/or avoid destruction by complement and other natural and acquired defense mechanisms . Here, Neil Cooper reviews the various mechanisms that pathogens have evolved to evade the destructive actions of the complement system, with particular emphasis on the many remarkable examples of the duplication of complement-like structural and functional epitopes by microorganisms . Such mimicry not only enables the pathogens to avoid destruction by complement-mediated mechanisms but also, in a number of instances, facilitates infection. Immunol Lett, 1991 Sep, 30(1), 129 - 32 The immunosuppressive agent FK506 inhibits in vitro expression of membrane-bound and soluble interleukin-2 receptors on resting but not on activated human lymphocytes; Karlsson H et al.; FK506 is a recently introduced immunosuppressive agent synthesised by the microorganism Streptomyces tskubaensis . It has been found to be more potent than Cyclosporin A in inhibiting T cell activation . We investigated its effects on the expression of membrane bound as well as soluble interleukin-2 receptors on human lymphocytes . The membrane-bound IL-2 receptor expression was inhibited by FK506 in resting lymphocytes at a concentration of 1 pmol/l . At 10 nmol/l no further inhibition was seen . In activated lymphocytes FK506 exerted no inhibitory effect on the IL-2 receptor expression . The release of soluble IL-2 receptor showed a pronounced decline in the concentration interval between 10 pmol/l and 0.1 nmol/l . Above a concentration of 10 nmol/l, no further decrease was seen . In activated lymphocytes the expression of soluble IL-2 receptors was unaffected by FK506 incubated up to 72 h . Pretreatment of the lymphocytes with the compound did not further depress the expression of the membrane-bound or the soluble receptor . Our results also indicate that the expression of the membrane-bound receptor is more sensitive to the drug than the soluble form of the receptor. J Forensic Sci, 1991 Sep, 36(5), 1284 - 98 Deoxyribonucleic acid (DNA) analysis by restriction fragment length polymorphisms of blood and other body fluid stains subjected to contamination and environmental insults; Adams DE et al.; Deoxyribonucleic acid (DNA) restriction fragment length polymorphism (RFLP) profile results were obtained from bloodstains and other body fluid stains subjected to mixture with other body fluids, environmental insults (sunlight and temperature), different substrates (cotton, nylon, blue denim, glass, aluminum, and wood), and contaminants (gasoline, bleach, sodium hydroxide, soil, motor oil, detergent, phosphate salt, glacial acetic acid, and microorganisms) . Of the samples that produced profile results, all had profiles that were consistent with those of untreated control samples. Lijec Vjesn, 1991 Sep-Oct, 113(9-10), 343 - 7 {Iron and infection}; Stojiljkovic I et al.; Iron is essential nutrient for the growth of the most pathogenic microorganisms . However in vivo iron is complexed with host proteins such as transferrin in the blood and lactoferrin in secretions so that it is not available as a free ionic iron . Restriction in the availability of free iron in the host, the so-called nutritional immunity plays a key role in nonspecific defence strategy against potential pathogens . To overcome the lack of free iron, microorganisms produce substances that chelate iron and they are called siderophores . The outcome of every infection is therefore dependent on both the level of free iron present in the host and the efficiency of siderophore-mediated iron uptake system of the pathogen. Appl Environ Microbiol, 1991 Sep, 57(9), 2473 - 81 Physical and chemical factors influencing transport of microorganisms through porous media; Fontes DE et al.; Resting-cell suspensions of bacteria isolated from groundwater were added as a pulse to the tops of columns of clean quartz sand . An artificial groundwater solution (AGW) was pumped through the columns, and bacterial breakthrough curves were established and compared to test the effects of ionic strength of the AGW, cell size (by using strains of similar cell surface hydrophobicity but different size), mineral grain size, and presence of heterogeneities within the porous media on transport of the bacteria . The proportion of cells recovered in the effluent ranged from nearly 90% for AGW of a higher ionic strength (I = 0.0089 versus 0.00089 m), small cells (0.75-micron-diameter spheres versus 0.75 by 1.8-micron rods), and coarse-grained sand (1.0 versus 0.33 mm) to less than 1% for AGW of lower ionic strength, large cells, and fine-grained sand . Differences in the widths of peaks (an indicator of dispersion) were significant only for the cell size treatment . For treatments containing heterogeneities (a vein of coarse sand in the center of a bed of fine sand), doubly peaked breakthrough curves were obtained . The first peak represents movement of bacteria through the transmissive coarse-grained vein . The second peak is thought to be dominated by cells which have moved (due to dispersion) from the fine-grained matrix to the coarse-grained vein near the top of the column and thus had been retarded, but not retained, by the column . Strength of effects tests indicated that grain size was the most important factor controlling transport of bacteria over the range of values tested for all of the factors examined.(ABSTRACT TRUNCATED AT 250 WORDS) Infect Immun, 1991 Sep, 59(9), 3053 - 9 Increase of T-cell receptor gamma/delta-bearing T cells in cord blood of newborn babies obtained by in vitro stimulation with mycobacterial cord factor; Tsuyuguchi I et al.; Cord blood T lymphocytes proliferated in vitro in response to mycobacterial organisms but did not proliferate in the presence of tuberculin purified protein derivative . Components recognized by cord blood T cells were resistant to protease digestion . In contrast, T lymphocytes derived from tuberculin-positive adult peripheral blood proliferated when stimulated by the protease-sensitive component of mycobacterial organisms or purified protein derivative, confirming that adult T cells respond to protein components whereas cord blood T cells respond to the nonpeptide component of mycobacteria . In vitro culture of cord blood lymphocytes stimulated by either mycobacterial lysates or the lipid fraction showed increases in the numbers of T-cell receptor (TcR) gamma/delta T lymphocytes with no changes in the numbers of TcR alpha/beta T lymphocytes in contrast to the in vitro cultures of adult blood lymphocytes stimulated with mycobacterial ligands in which no increase of TcR gamma/delta cells was observed . Interleukin-2 receptor (CD25) and Ia antigen (HLA-DR) analyses evidenced the activation of a large proportion of cord blood gamma/delta T cells which had increased after stimulation with mycobacteria in vitro . Further characterization of mycobacterial ligand suggested that the lipid fraction of mycobacterial lysate or trehalose dimycolate-cord factor was the most plausible cause for T-cell proliferation in cord blood . These results suggest that when the gamma/delta T cells in a newborn infant not yet sensitized to any pathogenic organisms are confronted by a mycobacterium, they respond nonspecifically to the mycobacterial organism or its lipid component (cord factor) . gamma/delta T cells may therefore play a distinct role in forming the first line of the host defense system against certain microorganisms. Experientia, 1991 Aug 15, 47(8), 791 - 803 Implications of toxins in the ecology and evolution of plant pathogenic microorganisms: bacteria; Mitchell RE; This review attempts to rationalise what is known about bacterial phytotoxins and associate it with the ecology and possible evolution of the producing organisms . Study of non-toxin producing variants gives insight into the ecological role of the toxin . Elucidation of chemical structures of phytotoxins has shown that many exist as families of analogous compounds . Studies on the variation of chemical structures and how they are distributed across species and genera can lead to development of hypotheses on evolutionary relationships . Knowledge on biosynthetic pathways to toxins allows recognition of specific enzymatic steps involved in developing the characteristic features of the structures . Phytotoxins often have a potent biochemical activity, and in some cases the producing organism has associated mechanisms to prevent action of the toxin upon itself; in such cases toxigenesis is clearly not a chance event . The various aspects of bacterial toxigenesis indicate that bacterial phytotoxins are special secondary metabolic products that play beneficial roles to the producing organisms in their various ecological niches. Biochem Biophys Res Commun, 1991 Aug 15, 178(3), 1273 - 9 Photoisomerization of retinal at 13-ene is important for phototaxis of Chlamydomonas reinhardtii: simultaneous measurements of phototactic and photophobic responses; Takahashi T et al.; A real-time automated method was developed for simultaneous measurements of phototactic orientation (phototaxis) and step-up photophobic response of flagellated microorganisms . Addition of all-trans retinal restored both photoresponses in a carotenoid-deficient mutant strain of Chlamydomonas reinhardtii in a dose-dependent manner . The phototactic orientation was biphasic with respect to both the light intensity and the concentration of retinal . All-trans retinal was more effective than 11-cis retinal to regenerate both photobehavioral responses . Analogs having locked 11-cis configurations and a phenyl ring in the side chain also induced photoresponses, although at concentrations more than two orders of magnitude higher than all-trans retinal . According to the present assay method, the responses were hardly detectable in cells incubated with retinal analogs in which the 13-ene was locked in either its trans or cis configuration . The results strongly suggest that the isomerization of the 13-14 double bond is important for photobehavioral signal transduction and that a single retinal-dependent photoreceptor controls both phototactic and photophobic responses. Appl Biochem Biotechnol, 1991 Aug, 30(2), 217 - 24 L-malic acid production using immobilized Saccharomyces cerevisiae; Figueiredo ZM et al.; L-Malate was produced from fumarate by using immobilized Saccharomyces cerevisiae cells entrapped in polyacrylamide . This preparation performed better when pretreated with malonate . Under the experimental conditions described here, succinate was not detected as a by-product of the reaction, as had been reported for other microorganisms. Appl Biochem Biotechnol, 1991 Aug, 30(2), 165 - 83 Anaerobic digestion of lignocellulosic biomass and wastes . Cellulases and related enzymes; Adney WS et al.; Anaerobic digestion represents one of several commercially viable processes to convert woody biomass, agricultural wastes, and municipal solid wastes to methane gas, a useful energy source . This process occurs in the absence of oxygen, and is substantially less energy intensive than aerobic biological processes designed for disposal purposes . The anaerobic conversion process is a result of the synergistic effects of various microorganisms, which serve as a consortium . The rate-limiting step of this conversion process has been identified as the hydrolysis of cellulose, the major polymeric component of most biomass and waste feedstocks . Improvements in process economics therefore rely on improving the kinetic and physicochemical characteristics of cellulose degrading enzymes . The most thoroughly studied cellulase enzymes are produced by aerobic fungi, namely Trichoderma reesei . However, the pH and temperature optima of fungal cellulases make them incompatible for use in anaerobic digestion systems, and the major populations of microorganisms involved in cellulase enzyme production under anaerobic digestion conditions are various bacterial producers . The current state of understanding of the major groups of bacterial cellulase producers is reviewed in this paper . Also addressed in this review are recently developed methods for the assessment of actual cellulase activity levels, reflective of the digester "hydrolytic potential," using a series of detergent extractive procedures. Med Hypotheses, 1991 Aug, 35(4), 279 - 87 Pathway to carcinogenesis: the role of bacterial spores; White MW; There are bacteria present within the malignant cell, but they are present only as spores . Although their origin stems from a branching or budding plant type of microorganism, the latter is not physically present and is not involved, per se, in the malignant cell's etiology . It is the primitive but now the asexual reproductive, conidial unicellular, ovular, or spherical shaped bodies, arising from the adult plant microorganism, in consequence to a duressing environment, but also the ones with the genetic capability of surviving within a sac or cell, that are present within the malignant cell . It is these spores, reproducing as spores within the malignant cell and within the immediate surrounding area, as long as there exists an adequate circulating flow of blood by the animal (human) host, to account for the anaerobic or preferably 'deoxygenating' metabolism that occurs in the malignant cell and is the reason for the cellular accumulation and tumor growth . This type of metabolism, respiration, and reproductive pattern is similar to that of the plant type of microorganism activity . In comparison, the healthy non-tumor tissue of animal (human) cells are genetically and primarily aerobic in respiration and metabolism . There are substantial suggestive findings and structural facts uncovered experimentally to definitely establish credence to the presence of those spores within the malignant cell and to align their presence to the pathway of activity, resulting in the etiology and physiopathology of the malignant cell and growth. Int J Exp Pathol, 1991 Aug, 72(4), 387 - 95 Experimental allergic alveolitis after exposure to different microorganisms; Fogelmark B et al.; The experiments described here examined the capacity of different microorganisms to induce allergic alveolitis . Guinea-pigs were exposed to an aerosol of pure cultures of five different organisms, four of which are common in mouldy hay, without previous injection of an adjuvant . The animals were either acutely exposed or exposed for 3 to 5 weeks, after which the numbers of different inflammatory cells in the airways were counted and histological changes in the lung parenchyma were assessed . It was seen that prolonged exposures to large numbers of spores produced a cellular infiltration in the alveolar and bronchiolar region, and gave rise to lesions resembling early granulomas . The number of lymphocytes increased in the airways . The results suggest that allergic alveolitis can be induced by inhalation of various kinds of microorganisms and that these may vary in their capacity to produce the disease. Epidemiol Infect, 1991 Aug, 107(1), 181 - 7 Cockroaches (Blattella germanica) as carriers of microorganisms of medical importance in hospitals; Fotedar R et al.; A study was conducted to isolate and identify microorganisms of medical importance from cockroaches (Blattella germanica) and to ascertain their vector potential in the epidemiology of nosocomial infections . Bacteria, fungi and parasites of medical importance were isolated and identified . Important bacterial pathogens responsible for wound infections, were further studies by antibiograms . One hundred and fifty-eight out of 159 (99.4%) cockroaches collected from hospital (test) and 113 out of 120 (94.2%) cockroaches collected from residential areas (control) were carrying medically important microorganisms (P less than 0.05) . significantly higher (P less than 0.001) number of test cockroaches were carrying a higher bacterial load (1 x 10(4) and 1 x 10(5} as compared to control cockroaches . Multiple drug-resistant bacterial were isolated from test cockroaches . The diversity of drug-resistant bacterial species isolated from test cockroaches suggests their involvement in the transmission of drug-resistant bacteria . Various fungi and parasitic cysts of medical importance were also isolated from the test and control cockroaches, but the carriage rates were low . The findings suggest that cockroaches, in hospitals, can act as potential vectors of medically important bacteria/parasites/fungi. Chest, 1991 Aug, 100(2), 567 - 8 Legionella pneumonia presenting as a bulging fissure on chest roentgenogram; Lucas RS et al.; We report a case of Legionella pneumonia presenting as a bulging interlobar fissure on the lateral chest roentgenogram . This microorganism should be added to the list of etiologic agents producing a bulging fissure on chest roentgenogram. Steroids, 1991 Aug, 56(8), 440 - 5 The identification of 14 alpha,17 beta-dihydroxyandrost-4-en-3-one monohydrate and 14 alpha,17 beta-dihydroxyandrosta-1,4-dien-3-one monohydrate, metabolites of androstenedione in Mucor piriformis; Krishnan R et al.; The microorganism Mucor piriformis transforms androst-4-ene-3,17-dione into a major and several minor metabolites . X-ray crystallographic analysis of two of these metabolites was undertaken to determine unambiguously their composition and chirality . Crystals belong to the orthorhombic space-group P2(1)2(1)2(1), with a = 7.199(4) A and a = 6.023(3) A, b = 11.719(3) A and b = 13.455(4) A, c = 20.409(3) A and c = 20.702(4) A for the two title compounds, respectively . The structures have been refined to final R values of 0.060 and 0.040, respectively. Anal Biochem, 1991 Aug 1, 196(2), 201 - 6 2-Nitro-5-(6-bromohexanoylamino)benzoic acid test paper method for detecting microorganisms capable of producing cephalosporin acylases; Zhang QJ et al.; A novel method for detecting microorganisms capable of producing cephalosporin C (CPC) acylase and/or 7-(4-carboxybutanamido)cephalosporanic acid (GL-7-ACA) acylase has been developed . The method is based on the degradation of 2-nitro-5-(6-bromohexanoylamino)benzoic acid (NBHAB), a chromogenic substrate, into yellow 2-nitro-5-aminobenzoic acid by the action of the CPC acylase or the GL-7-ACA acylase . This method is very sensitive and quite specific, and has been successfully applied to screen the acylases from a variety of bacteria . A large number of colonies isolated on a plate surface from more than 67 samples and several known bacteria were tested by the NBHAB paper . Five NBHAB-positive strains and isolates were obtained . They were further examined by the reaction of their bacterial cells upon CPC and GL-7-ACA, respectively, and by thin-layer chromatography in order to distinguish the CPC acylase from the GL-7-ACA acylase. Appl Environ Microbiol, 1991 Aug, 57(8), 2293 - 301 Regiospecific dechlorination of pentachlorophenol by dichlorophenol-adapted microorganisms in freshwater, anaerobic sediment slurries; Bryant FO et al.; The reductive dechlorination of pentachlorophenol (PCP) was investigated in anaerobic sediments that contained nonadapted or 2,4- or 3,4-dichlorophenol (DCP)-adapted microbial communities . Adaptation of sediment communities increased the rate of conversion of 2,4- or 3,4-DCP to monochlorophenols (CPs) and eliminated the lag phase before dechlorination was observed . Both 2,4- and 3,4-DCP-adapted sediment communities dechlorinated the six DCP isomers to CPs . The specificity of chlorine removal from the DCP isomers indicated a preference for ortho-chlorine removal by 2,4-DCP-adapted sediment communities and for para-chlorine removal by 3,4-DCP-adapted sediment communities . Sediment slurries containing nonadapted microbial communities either did not dechlorinate PCP or did so following a lag phase of at least 40 days . Sediment communities adapted to dechlorinate 2,4- or 3,4-DCP dechlorinated PCP without an initial lag phase . The 2,4-DCP-adapted communities initially removed the ortho-chlorine from PCP, whereas the 3,4-DCP-adapted communities initially removed the para-chlorine from PCP . A 1:1 mixture of the adapted sediment communities also dechlorinated PCP without a lag phase . Dechlorination by the mixture was regiospecific, following a para greater than ortho greater than meta order of chlorine removal . Intermediate products of degradation, 2,3,5,6-tetrachlorophenol, 2,3,5-trichlorophenol, 3,5-DCP, 3-CP, and phenol, were identified by a combination of cochromatography (high-pressure liquid chromatography) with standards and gas chromatography-mass spectrometry. Appl Environ Microbiol, 1991 Aug, 57(8), 2135 - 40 Propachlor degradation by a soil bacterial community; Villarreal DT et al.; Soil from a pesticide disposal site was used to enrich for microorganisms that degraded the acylanilide herbicide propachlor (2-chloro-N-isopropylacetanilide) . After seven transfers of the enrichment, the culture contained about six strains . The highest yield of microbial biomass occurred if just two of these isolates, strains DAK3 and MAB2, were inoculated into a mineral salts medium containing propachlor . When only strain DAK3 was grown on propachlor, a metabolite (2-chloro-N-isopropylacetamide) was released into the medium . Strain MAB2 could grow on this metabolite . The results of morphological and physiological tests suggest that strains DAK3 and MAB2 most closely resemble species belonging to the genera Moraxella and Xanthobacter, respectively . Strain DAK3 can respire and grow on N-substituted acylanilides containing methyl, ethyl, or isopropyl substitutions, but is incapable of respiration or growth on acetanilide, aniline, or the acylanilide herbicides alachlor and metolachlor . Strain DAK3 appears to use the aromatic C atoms of propachlor for growth, as suggested by the growth yield on propachlor and the induction of catechol 2,3-oxygenase activity in acylanilide-grown cells. Eur J Clin Microbiol Infect Dis, 1991 Aug, 10(8), 620 - 4 Evaluation of the new improved BHI-lysis blood culture medium for the BCB Roche system; Rohner P et al.; The new BHI-lysis blood culture medium for the BCB system (BCB release, Hoffmann-La Roche), which lyses blood cells, was compared with the BHI-S broth of the same BCB system and the Signal system (Oxoid) . A total of 2394 sets consisting of three bottles were each inoculated with 7 ml of blood at the bedside . In the laboratory agar-coated paddles were attached to the BHI-lysis and the BHI-S bottles, and the Signal device was mounted onto the Oxoid bottle . All systems were incubated at 35 degrees C for seven days . Of the 309 (13%) positive sets, 73 (3%) were contaminated and in 242 (10%) sets a total of 250 pathogenic microorganisms were isolated . These could be grown significantly more often from the BHI-lysis bottle (n = 213) than from either the BHI-S (n = 189) or Signal bottle (n = 176) . No significant differences in the time needed to achieve a positive result was noted between the BHI-lysis and BHI-S bottles, but comparison of the BHI-lysis and Signal bottles revealed that overall pathogens were detected earlier significantly more often with the BHI-lysis bottle . In view of the good performance of blood culture broths containing lysing agents, their wider use is warranted in future. J Nutr, 1991 Aug, 121(8), 1236 - 42 Rumen succinate production may ameliorate the effects of cobalt-vitamin B-12 deficiency on methylmalonyl CoA mutase in sheep; Kennedy DG et al.; When lambs were fed a cobalt-deficient whole barley diet there was a rapid and massive increase in rumen succinate concentrations . Within 2 d of feeding the Co-deficient diet, the rumen succinate concentrations rose 200-fold and peaked at a level 1000-fold higher than that in Co-sufficient controls . Rumen propionate concentrations decreased, suggesting that an alteration in the balance between succinate- and propionate-producing microorganisms had occurred . The rumen succinate can be absorbed and thus may lead to elevated plasma succinate concentrations in Co-deficient animals, whether fed barley or grass . Thus, the absorbed succinate can at least partially overcome the effect on gluconeogenesis of a decreased activity of methylmalonyl CoA mutase induced by Co-deficiency . These findings suggest that impaired propionate metabolism may not be the primary metabolic defect in ovine Co-deficiency. Surgery, 1991 Aug, 110(2), 303 - 9; discussion 309-10 Selective decontamination of the digestive tract: a stratified, randomized, prospective study in a mixed intensive care unit; Blair P et al.; To evaluate the use of selective decontamination of the digestive tract (SDD) (polymyxin, amphotericin, tobramycin, and intravenous cefotaxime) in a mixed intensive care unit, we performed a stratified, randomized, prospective study . The 331 patients were recruited over an 18-month period, with 256 patients remaining more than 48 hours . Stratification by acute physiology and chronic health evaluation (APACHE II) preceded randomization to control (standard antibiotic therapy) or treatment (SDD) groups . Nosocomial infection was significantly reduced in the SDD group (16.7%; 21 of 126 patients) compared with the control group (30.8%; 40 of 130 patients; p = 0.008) . No difference was found in overall mortality rate or length of stay between the two groups . Those patients with admission APACHE II scores 10 to 19 demonstrated the most significant reduction in nosocomial infection (23 of 70 control vs 13 of 76 SDD; p = 0.03) and mortality (15 of 70 control vs 8 of 76 SDD; p = 0.07) . Emergence of multiresistant microorganisms was not a clinical problem, but a definite change occurred in the ecology of environmental and colonizing bacteria . With the exception of cefotaxime, a reduction was noted in systemic antibiotic usage in the SDD group . We conclude that SDD is useful in selected patients in a mixed intensive care unit. Curr Opin Biotechnol, 1991 Aug, 2(4), 532 - 8 Routes to active proteins from transformed microorganisms; Buchner J et al.; Over-expression of recombinant proteins in microbial hosts results in the formation of active soluble protein or of insoluble aggregates (inclusion bodies) . Efficient in vitro refolding strategies have been developed to reactivate inactive proteins from inclusion bodies . Co-expression of molecular chaperones may provide a tool to promote correct structure formation of recombinant proteins in vivo. J Immunol Methods, 1991 Jul 26, 141(1), 73 - 9 Mannan-binding protein in human liver; Ryley NG et al.; Mannan-binding protein (MBP) is a Ca(2+)-dependent lectin which was first described in 1978 in rabbit liver, and subsequently in serum and liver tissue from humans and a range of animal species . MBP structurally resembles C1q, and may act both as a focus for complement activation on the surface of microorganisms and as an opsonin in its own right . Low serum levels of serum MBP have been described in a group of children known to suffer from severe recurrent infections . MBP has also been reported to behave as an acute phase reactant . This preliminary study has investigated the localisation of MBP in human tissues using material obtained both at post mortem and from diagnostic liver biopsies . Using the IgG fraction of rabbit anti-human MBP, immunoperoxidase staining showed no evidence of significant MBP in a wide range of normal tissues, including liver taken both at post mortem and needle biopsy . However, there was a significant degree of staining for MBP in liver biopsies showing a variety of different pathologies, in particular severely damaged alcoholic livers, and those harbouring metastatic tumour . Moderate degrees of staining were also seen in liver biopsies from patients suffering from chronic biliary disease . It is uncertain whether this localisation of MBP in abnormal liver is an acute phase response, or represents a more fundamental link with liver disease . This question could be the focus for future studies. Ugeskr Laeger, 1991 Jul 22, 153(30), 2131 - 3 {Pericarditis with pericardial tumor-like manifestations in echocardiographic and magnetic resonance examinations}; Yndgaard S et al.; A case of acute cardiac insufficiency in a 26 year old woman is described . Ultrasound examination of the pericardium was suspect for an pericardial tumor with pericardial effusion and solid masses of tumor in the fluid . Magnetic resonance imaging (MRI) gave the impression of tumor in the pericardium . Pericardiocentesis showed neither malignant cells nor growth of microorganisms . The patient recovered completely on steroid therapy and control MRI showed anatomic normalisation of the cardiac region . It is concluded that idiopatic peracarditis can mimic pericardial tumor on ultrasound and MRI investigation. Surg Gynecol Obstet, 1991 Jul, 173(1), 73 - 83 Bacterial translocation; Edmiston CE Jr et al.; The phenomenon of bacterial translocation, the movement of viable indigenous microorganisms across the intestinal epithelial barrier, has been recognized for almost 100 years . At the present time, the precise mechanism of microbial transport is unknown . Active epithelial uptake and phagocyte-mediated transport have been proposed as likely explanations for the extraintestinal movement of bacteria to mesenteric lymph nodes and distant organ sites . Translocation has been proposed as the pivotal process associated with intestinal origin portal sepsis in seriously ill and immunocompromised patients . While several etiologic factors can be implicated in the pathogenesis of bacterial translocation, the present clinical implications are based almost solely on studies of dogs, rats and mice . Present investigations continue to suggest a causal relationship between intestinal mucosal integrity and infection by indigenous gastrointestinal bacteria. J Immunol Methods, 1991 Jul 5, 140(2), 211 - 8 A radioimmunoassay for the determination of insulins from several animal species, insulin derivatives and insulin precursors in both their native and denatured state; Mullner S et al.; Antibodies were raised against the carboxy terminus of the insulin A chain in sheep, goat and rabbit using as antigen the synthetic octapeptide YQLENYCN conjugated to bovine serum albumin (BSA) . All of the antisera obtained cross-reacted with molecules containing this peptide sequence . Using these antibodies, we developed a radioimmunoassay that could detect the insulin A chain itself, both denatured and natural mammalian and avian insulins, as well as proinsulins and insulin fusion proteins from microorganisms. APMIS, 1991 Jul, 99(7), 620 - 6 Radiation resistance of microorganisms on unsterilized infusion sets; Christensen EA et al.; Three different methods were used for detecting and isolating microorganisms with high radiation resistance from the microbial contamination on infusion sets prior to sterilization . By all three methods, microorganisms with a radiation resistance high enough to be a critical factor in a sterilization process (D-6 value greater than or equal to 30 kGy) were found with a frequency of approximately two colony forming units (cfu) per 100 product items, even though the product items in two of the series of analyses were irradiated with doses of 3-6 kGy . The frequency of occurrence of isolates with D-6 values greater than or equal to 30 kGy was 0.45 per 1000 cfu of the total aerobic count . Eight different isolates of microorganisms had D-6 values greater than or equal to 40 kGy when irradiated in dried laboratory preparation . All but one of these were classified according to morphologic criteria as Deinococcus, and all but one had nonlinear dose-response relationships in semilogarithmic presentation. Mutat Res, 1991 Jul, 249(1), 37 - 54 Most ultraviolet irradiation induced mutations in the nematode Caenorhabditis elegans are chromosomal rearrangements; Stewart HI et al.; In this study we have determined the utility of 254-nm ultraviolet light (UV) as a mutagenic tool in C . elegans . We have demonstrated that irradiation of adult hermaphrodites provides a simple method for the induction of heritable chromosomal rearrangements . A screening protocol was employed that identifies either recessive lethal mutations in the 40 map unit region balanced by the translocation eT1(III;V), or unc-36(III) duplications . Mutations were recovered in 3% of the chromosomes screened after a dose of 120 J/m2 . This rate resembles that for 1500 R gamma-ray-induced mutations selected in a similar manner . The mutations were classified either as lethals {mapping to Linkage Group (LG)III or LGV} or as putative unc-36 duplications . In contrast to the majority of UV-induced mutations analysed in microorganisms, we found that a large fraction of the C . elegans UV-induced mutations are not simple intragenic lesions, but are deficiencies for more than one adjacent gene or more complex events . Preliminary evidence for this conclusion came from the high frequency of mutations that had a dominant effect causing reduced numbers of adult progeny . Subsequently 6 out of 9 analysed LGV mutations were found to be deficiencies . Other specific rearrangements also identified were: one translocation, sT5(II;III), and two unc-36 duplications, sDp8 and sDp9 . It was concluded that UV irradiation can easily be used as an additional tool for the analysis of C . elegans chromosomes, and that C . elegans should prove to be a useful organism in which to study the mechanisms whereby UV acts as a mutagen in cells of complex eukaryotes. Health Phys, 1991 Jul, 61(1), 137 - 42 Autoclave inactivation of infectious radioactive laboratory waste contained within a charcoal filtration system; Stinson MC et al.; A model system was developed previously for disposal of solid laboratory waste that is both radioactive and heat sensitive, e.g., HIV . A double polypropylene bag with charcoal vent filter and absorbent was designed to meet requirements for both steam sterilization and disposal as solid radioactive waste . Earlier work demonstrated the effective containment of radioactive gases by the filter and inactivation of organisms as heat sensitive as HIV . We sought to broaden the application of this model to ensure inactivation of microorganisms that are more heat resistant than HIV . The efficacy of steam sterilization using water or solutions of iodophor, hypochlorite, or hydrogen peroxide was studied under constant temperature and time conditions . The systems were monitored with internal probes, physical, chemical, and biological indicators . Biological indicators documented inactivation when bags containing hydrogen peroxide (3%) were autoclaved for 60 min at 121 degrees C . Synergistic activity between hydrogen peroxide and autoclave conditions significantly reduced processing time. J Infect Dis, 1991 Jul, 164(1), 188 - 91 Adjuvant effect of human growth hormone with an inactivated flavivirus vaccine; Stephenson JR et al.; Vaccines made by inactivating pathogenic microorganisms have been dramatically successful in controlling diseases in humans and animals . Despite their successes, they have a major disadvantage in that several inoculations are required for them to be effective . To overcome this problem, a commercial inactivated vaccine preparation against tickborne encephalitis was combined with human growth hormone (HGH) . This formulation produced complete protection in a murine model with only one dose of vaccine, apparently by binding hormone and antigen to an insoluble matrix containing aluminium hydroxide . Thus it is postulated that when virus-specific lymphocytes are attracted to the site of injection, the hormone is at a high local concentration and stimulates the clonal expansion of antigen-specific T cells . The development of genetically engineered HGH now gives unlimited supplies of hormone, potentially resulting in an increase in efficacy of a wide variety of vaccines, especially those needing prolonged immunization schedules such as those being developed to combat human immunodeficiency virus infection. Infect Immun, 1991 Jul, 59(7), 2359 - 63 Oral immunization against Helicobacter pylori; Czinn SJ et al.; Helicobacter pylori, which has been associated with gastritis and duodenal ulcers, commonly chronically infects adults . Eradication of this microorganism, which is difficult to achieve, results in normalization of gastritis and marked reduction in the relapse rate of duodenal ulcers . Since eradication is difficult to achieve, prevention of initial colonization of the gastrointestinal tract may be a viable alternative for abrogation of H . pylori-associated gastroduodenal disease . To test the feasibility of this approach, mice and ferrets were orally immunized with killed H . pylori . Immunization induced immunoglobulin A and G anti-H . pylori antibodies in both gastrointestinal secretions and sera of mice . These responses were enhanced when cholera toxin was included in the immunization protocol as a mucosal adjuvant . In ferrets, addition of cholera toxin resulted in significant enhancement of anti-H . pylori antibody levels in sera and intestines . Thus, oral immunization with killed H . pylori may be feasible approach to protect hosts from this infection and the accompanying gastroduodenal disease. Kosm Biol Aviakosm Med, 1991 Jul-Aug, 25(4), 4 - 10 {Medico-biological effects of natural UV-radiation: global consequences of the destruction of the ozone layer}; Strzhizhovskii AD et al.; The effect of UV-B-radiation of high intensity on terrestrial microorganisms, aqueous ecosystems, and plants is described . The effect of UV-B-radiation on humans and animals is discussed and quantitative evaluation of ozone layer destruction is given . It is indicated that potential changes will grow continuously, producing a significant effect on the biosphere . It is concluded that UV-B-radiation as a stimulating agent should be applied with caution in general biology and medicine and in space biology and medicine. Lipids, 1991 Jul, 26(7), 512 - 6 Sesamin is a potent and specific inhibitor of delta 5 desaturase in polyunsaturated fatty acid biosynthesis; Shimizu S et al.; Incubation with sesame oil increases the mycelial dihomo-gamma-linolenic acid content of an arachidonic acid-producing fungus, Mortierella alpina, but decreases its arachidonic acid content {Shimizu, S., K . Akimoto, H . Kawashima, Y . Shinmen and H . Yamada (1989) J . Am . Oil Chem . Soc . 66, 237-241} . The factor causing these effects was isolated and identified to be (+)-sesamin . The results obtained in experiments with both a cell-free extract of the fungus and with rat liver microsomes demonstrated that (+)-sesamin specifically inhibits delta 5 desaturase at low concentrations, but does not inhibit delta 6, delta 9 and delta 12 desaturases . Kinetic analysis showed that (+)-sesamin is a noncompetitive inhibitor (Ki for rat liver delta 5 desaturase, 155 microM) . (+)-Sesamolin, (+)-sesaminol and (+)-episesamin also inhibited only delta 5 desaturases of the fungus and liver . These results demonstrate that (+)-sesamin and related lignan compounds present in sesame seeds or its oil are specific inhibitors of delta 5 desaturase in polyunsaturated fatty acid biosynthesis in both microorganisms and animals. Dent Assist, 1991 Jul-Aug, 60(4), 10 - 4 Dental caries: selected factors of children at risk; McCormack-Brown KR et al.; This article reviews the dental caries risk factors of children by using an epidemiological model which has three interrelated factors--agent, host, and environment . Dental caries agent factors include microorganisms with cariogenic potential; host factors include gender, race, tooth arrangement, sugar consumption, knowledge, attitudes, and behaviors; environmental factors include type of community (rural vs . urban), socioeconomic status, use of dental services and fluoride . This article reviews these selected dental caries risk factors and describes how dental assistants can practically apply this information. Rev Infect Dis, 1991 Jul-Aug, 13 Suppl 9, S763 - 9 Empiric therapy for the immunocompromised host; Armstrong D; The use of empiric therapy for immunocompromised hosts has been one of the major advances in the management of such patients . Such therapy has been put into practice primarily for patients with neutropenia induced by cytotoxic chemotherapy . The empiric antibiotic regimens include in their coverage the bowel, skin, and intravenous-catheter flora anticipated for patients in a particular hospital . Less often, physicians treat empirically for opportunistic infections that complicate defects in helper cells, although empiric therapy for presumed Pneumocystis carinii pneumonia and Toxoplasma gondii infection of the central nervous system has become commonplace for patients infected with human immunodeficiency virus . Physicians also should consider environmental factors that expose patients to certain opportunistic organisms . Examples of such pathogens include Mycobacterium tuberculosis and Histoplasma capsulatum . The particular microorganisms considered to be opportunistic vary in different parts of the world and in different hospitals, and their designation as such may change rapidly . Multiple environmental exposures and immune defects, rather than just one factor, may be responsible for opportunistic infections and should be investigated and taken into account when empiric therapy is planned . Preventive measures, including simply rigorous hygiene, should precede and may obviate the need for empiric therapy. Mol Biol Evol, 1991 Jul, 8(4), 530 - 44 An extreme codon preference strategy: codon reassignment; Andersson GE et al.; We argue that in animal mitochondria codon reassignments, such as those for AGA and AGG from arginine to serine or of AUA from isoleucine to methionine, are the result of an interplay between biased mutational forces and selective ones . In particular, there is a marked tendency for animal mitochondria to have very small genomes and to minimize their investment in components required for gene expression . These tendencies are expressed as a reduction in the diversity of tRNA isoacceptor species . In our view, the pressure to simplify tRNA populations, together with mutational bias against certain codons, will account for the codon reassignments observed in animal mitochondria . A parallel to the major codon bias in microorganisms, which likewise tends to reduce the diversity of the tRNA isoacceptor populations under fast growth conditions, may be drawn . Therefore, we suggest that codon reassignments are usefully viewed as an extreme form of codon bias. Int J STD AIDS, 1991 Jul-Aug, 2(4), 280 - 4 Primary and secondary syphilis: a histopathological study; Engelkens HJ et al.; We present a study of biopsies taken from skin lesions of 44 patients presenting with primary or secondary syphilis . In most primary lesions erosion or, more often, ulceration was present, with a dense inflammatory infiltrate . In secondary syphilis a wide variety of histological changes was present . Blood vessels were frequently involved, with marked endothelial swelling and often proliferation . Treponemes were demonstrated with the Steiner staining method in all investigated cases of primary syphilis and in 71% of secondary syphilis cases . Treponemes were present throughout the dermis, particularly perivascularly, and in the dermal-epidermal junction zone . In two specimens of secondary syphilis treponemes were located predominantly in the epidermis, but there were always some microorganisms demonstrable in the dermis . The inflammatory infiltrate was often located in a perivascular coat-sleeve-like arrangement . In this study plasma cells and lymphocytes were present in all specimens of primary and secondary syphilis . Syphilitic lesions differed from yaws lesions mostly in the location of treponemes and the affection of blood vessels . In this histopathological study of early syphilis, treponemes did not show the epidermiotropic character of yaws, and blood vessel changes were more pronounced than in yaws . Unfortunately, due to the protean histopathological manifestations described in venereal syphilis and in yaws, these two treponemal diseases cannot always be differentiated on histological grounds alone. J Invertebr Pathol, 1991 Jul, 58(1), 67 - 74 Parasitism of newly-hatched Aedes sierrensis (Diptera: Culicidae) larvae by Lambornella clarki (Ciliophora: Tetrahymenidae) following habitat flooding; Washburn JO et al.; Host-parasite interactions between Lambornella clarki (Ciliophora: Tetrahymenidae) and its natural host, Aedes sierrensis (Diptera: Culicidae), were studied in newly flooded treeholes in northern California between 1986 and 1989 . First instar host larvae hatched within 1 to 4 hr of flooding, while free-living trophonts of L . clarki appeared between 7 and 24 hr . As early as 24 hr after flooding, ciliates initiated the first parasite cycle by forming cuticular cysts on first instar larvae; by 64 hr, cysts were observed on larvae collected from all positive holes during all years . While larvae with as many as 12 cysts were observed, most supported only 1 cyst, and successful infections were established by the entry of a single ciliate into the host's hemocoel . Among treehole populations, the proportion of larvae with L . clarki cysts ranged from 2 to 100% at 48 hr indicating that enzootics and epizootics develop rapidly in newly flooded treeholes . Average attack rates from all holes by year ranged between 17.0 and 44.4% . Ciliates began entering hosts 48 to 72 hr after flooding, but some larvae escaped parasitization by molting to the second instar before ciliates penetrated the cuticle . In some treeholes, opportunistic microorganisms entered larvae with the invading ciliates and killed both the host and parasite. Orthop Clin North Am, 1991 Jul, 22(3), 523 - 30 Diagnosis and management of the infected total joint arthroplasty; Cuckler JM et al.; The preoperative diagnosis of the infected orthopedic implant is complicated by lack of a single precise test to forewarn patient and surgeon of the presence of microorganisms . Given the overall limitation of accuracy of preoperative diagnosis to approximately 80% when 111In scanning, preoperative aspiration, and ESR are considered, it would seem prudent to approach each revision surgery with the possibility in mind of subclinical sepsis as the cause for failure of the implant . The essentials of surgical technique including thorough debridement of the wound and removal of all existing foreign bodies, especially including PMMA bone cement, are critical to minimizing the risk for occurrence or persistence of sepsis . Although the use of antibiotic impregnated bone cement may enhance the treatment of orthopedic sepsis, the data available to date lead to the conclusion that two-stage revision surgery in the face of known sepsis remains the cornerstone of surgical therapy for the infected implant, along with aggressive and rational antibiotic treatment . The surgeon is offered the following guidelines in the management of the septic total hip arthroplasty . 1 . Preoperative evaluation including ESR, 111In WBC scan, and aspiration for culture and sensitivity (fluoroscopically guided for the hip) will produce on average approximately 80% accuracy . 2 . Intraoperative cultures at the time of revision surgery should be obtained prior to administration of systemic antibiotics; three tissue specimens (hip capsule, femoral membrane, acetabular membrane) should be submitted for culture and sensitivity determination . 3 . Careful debridement of the surgical site of granulation tissue and all foreign bodies (e.g., PMMA) should be performed within the limits of patient safety to maximize the likelihood of success.(ABSTRACT TRUNCATED AT 250 WORDS) Orthop Clin North Am, 1991 Jul, 22(3), 401 - 18 Diagnostic imaging of musculoskeletal infection . Roentgenography; gallium, indium-labeled white blood cell, gammaglobulin, bone scintigraphy; and MRI; Wegener WA et al.; A great deal of effort has been made to evaluate and define the role of various diagnostic imaging techniques in various clinical settings that complicate the diagnosis of osteomyelitis . Except possibly in neonates, bone scintigraphy remains generally recommended when there has been no previous osseous involvement . In other cases of chronic disease, previous fracture or trauma, prosthesis, and diabetic foot, In-WBC scintigraphy is generally accepted as an appropriate imaging technique . MRI will play an increasingly important role in diagnosing osteomyelitis and may prove to be an important adjunct in these cases . Research continues to improve our current diagnostic armamentarium . In-IgG appears to avoid practical deficiencies encountered with 67Ga and In-WBC; it remains to be seen what role this agent will play in routine clinical practice . All agents to date image inflammation, not infection, and most require delayed imaging sessions, usually at 24 hours . These shortcomings necessitate further research to develop new radiotracers that can provide useful images within several hours and that are specific for infection, perhaps ultimately delineating the particular microorganism involved. Yakugaku Zasshi, 1991 Jul, 111(7), 345 - 58 {Proline specific peptidases and their specific inhibitors}; Yoshimoto T; Several proline specific peptidases were newly isolated from mammalian organs, plants and microorganisms, and their enzymatic properties characterized . The genes of prolyl endopeptidase, aminopeptidase P and proline iminopeptidase from some microorganisms were cloned and their nucleotide sequences determined . By high expression of these genes in Escherichia coli, the enzymes became possible to be used for the industrial application as well as its basic research . Novel inhibitors specific for the prolyl endopeptidase and dipeptidyl aminopeptidase IV were synthesized and some inhibitors for prolyl endopeptidase found to show an anti-amnesic effect. Stomatologiia (Mosk), 1991 Jul-Aug, (4), 5 - 10 {The role of lipid peroxidation in the pathogenesis of periodontitis}; Voskresenskii ON et al.; The authors analyze the role of the factors promoting a disruption of the physiologic antioxidant system, such as nervous stress, hypodynamia, bioantioxidant insufficiency, and inadequate pro-oxidant supply, to the development of peroxidation mechanisms of periodontitis initiation . The suggested concept implies that the general etiologic factors responsible for disruption of the physiologic system of lipid peroxidation inhibition create a background low-level antioxidant protection of the periodontal tissues . Under such conditions the local factors (dental deposit, plaques, microorganisms) conducive to neutrophil migration to the gingiva and gingival fluid lead to a break out of lipid peroxidation in soft tissues of the periodontium; this break out is induced by free radicals (O2- et al.) that are produced in "respiration explosion" of phagocytizing leukocytes . Regular outbursts of lipid peroxidation represent the trigger mechanism in the development of morphofunctional changes in the periodontium and its vessels, resulting in collagen destruction and bone tissue resorption . The authors emphasize the usefulness of antioxidants in drug prophylaxis of periodontitis. J Endod, 1991 Jul, 17(7), 316 - 8 Copper-zinc superoxide dismutase activity in normal and inflamed human dental pulp tissue; Davis WL et al.; Information regarding the presence of the free radical scavenging (inactivating, dismutating) enzyme superoxide dismutase in human dental pulp was sought . Free radicals, such as the superoxide anion radical (O2-) and the hydroxyl anion radical (OH.), are powerful biological oxidants produced by phagocytes during the normal tissue response to injury and infection . Also produced is hydrogen peroxide (H2O2), an aggressive oxygen species formed by the reaction of superoxide with itself, i.e., a dismutation in which one molecule of O2- is oxidized by the other . These three reactive oxygen intermediates serve as part of the normal host biological defense mechanism for the inactivation of microorganisms and the breakdown of their toxic products . Both normal and inflamed dental pulps were assayed for the presence of this enzyme . Superoxide dismutase activity was identified in the normal pulpal tissues . There was a slight decrease in activity with age . In the inflamed pulpal tissues, enzyme activity was markedly and significantly increased in comparison to that in the normal tissues . These observations indicate that human dental pulp possesses an endogenous defense mechanism designed to protect the tissue components (cells and matrix) from the toxic effects of the reactive oxygen intermediates . In this regard, the inflammatory response of this specialized and somewhat isolated (compartmentalized) tissue is not unlike that seen in other connective tissues. Rev Infect Dis, 1991 Jul-Aug, 13(4), 721 - 35 Bacterial adhesion: genetics, biogenesis, and role in pathogenesis of fimbrial adhesins of Escherichia coli; Krogfelt KA; Microbial pathogenicity is a complex phenomenon encompassing many varied mechanisms . There are, however, several common strategies that pathogenic organisms use to sustain themselves and overcome host barriers . In one of these strategies, the first step is the firm adhesion of the microorganism to host cells . Adhesion is frequently mediated by organelles called fimbriae . A surprising variety of fimbrial adhesins have been found in Escherichia coli, and several have been extensively characterized . The genetics and regulation of the various fimbrial structures are reviewed, and strategies for preventing the adhesion of harmful bacteria to host surfaces are discussed. Infect Immun, 1991 Jul, 59(7), 2364 - 9 Genetic control of serum antibody responses of inbred mice to type 1 and type 2 fimbriae from Actinomyces viscosus T14V; Haber J et al.; Antibodies reactive with type 1 and type 2 fimbriae from Actinomyces viscosus T14V specifically inhibit the adherence of A . viscosus T14V to salivary pellicle-coated tooth surfaces and other bacteria, and these antibodies are thought to modulate colonization by this microorganism . These studies were done to determine whether previously noted differences in the antibody responses of inbred mice to type 1 and type 2 fimbriae might be under genetic control . The serum immunoglobulin G (IgG) and IgM antibody responses of inbred, F1 hybrid, and H-2 congenic mice, immunized with A . viscosus T14V cells, were analyzed by enzyme-linked immunosorbent assays for antibodies reactive with A . viscosus T14V whole-cell type 1 and type 2 fimbriae . The results confirmed earlier findings and indicated striking variations in the amounts of IgG anti-type 1 (23-fold) and anti-type 2 (48-fold) fimbria antibodies elicited . The responses of the 17 inbred strains tested showed a relatively continuous distribution from high to low, as well as marked differences in the responses of H-2 and Igh-C identical strain pairs . An analysis of the responses of F1 hybrid and H-2 congenic mice indicated dominance of the low-responder gene(s) and control by H-2-linked genes . Antisera from two high-responder strains inhibited in vitro bacterial adherence to a much greater degree than antisera from a low-responding strain . These data suggest polygenic control of the magnitude of the IgG anti-type 1 and anti-type 2 fimbria antibody responses by H-2-linked genes as well as background genes not associated with H-2 or Igh-C loci. Gac Sanit, 1991 Jul-Aug, 5(25), 169 - 73 {Food poisoning outbreak probably of viral etiology caused by Norwalk virus}; Arnedo Pena A et al.; In May 1989, a foodborne outbreak of acute gastroenteritis was identified in a state school in Adzaneta, Castellon . A dtudy was undertaken to describe it, investigate its causes, and recommend adequate control measures . Sixteen children and 2 teachers were affected (attack rate: 28.57%) . Kaplan and cols clinical and epidemiological criteria for Norwalk-like virus as the responsible agent were present . The probable origin of the outbreak was a foodhandler who was already ill beforehand . The examination of stools of the foodhandler and a patient showed small round structures similar to the Norwalk virus . In Spain, the number of foodborne outbreaks without known causal agent has steadily increased in recent years . It may be that this microorganism is responsible for some of these outbreaks in which, for several reasons, the causal agent cannot be identified. Rev Infect Dis, 1991 Jul-Aug, 13 Suppl 9, S727 - 32 Evolution of beta-lactamase inhibitors; Rolinson GN; The production of beta-lactamase is the most important mechanism of bacterial resistance to beta-lactam antibiotics . Attempts to find an inhibitor of beta-lactamase were made as early as the 1940s and 1950s but without success . In the early 1950s, it was found that certain semisynthetic penicillins could function as beta-lactamase inhibitors, but none found a clinical place in this capacity . A program of screening microorganisms for the production of naturally occurring inhibitors was begun in 1967 . This process led to the discovery of the olivanic acids and clavulanic acid . Clavulanic acid, formulated with amoxicillin and later with ticarcillin, became available for clinical use in 1981 . Since the introduction of clavulanic acid, other beta-lactamase inhibitors have been developed, including sulbactam and tazobactam . It remains to be seen whether these will have any advantage over clavulanate for clinical use. Appl Microbiol Biotechnol, 1991 Jul, 35(4), 496 - 503 Expression of human antithrombin III in the cellular slime mould Dictyostelium discoideum; Dingermann T et al.; In order to test the biotechnological potential of the cellular slime mould Dictyostelium discoideum the cDNA coding for human antithrombin III was expressed in this microorganism . The 1392-bp antithrombin III cDNA was fused to the N-terminal coding part of the D . discoideum actin 6 gene . In constructs carrying this artificial N-terminal coding region only low amounts of antithrombin III were detected . However, constructs from which all actin coding nucleotides were removed produced significant amounts of anti-thrombin III, most of which was secreted into the culture broth . Stationary cultures (1.5 x 10(7) cells/ml) of certain stable transformants accumulated up to 1.0 microgram antithrombin III/ml culture medium within 24 h . The recombinant protein has a slightly smaller molecular weight in sodium dodecyl sulphate-polyacrylamide gels than authentic plasma antithrombin III and it is glycosylated, as determined by concanavalin A labelling. Proc Natl Acad Sci U S A, 1991 Jun 15, 88(12), 5129 - 33 Are eukaryotic microorganisms clonal or sexual? A population genetics vantage; Tibayrenc M et al.; We argue that the mode of reproduction of microorganisms in nature can only be decided by population genetic information . The evidence available indicates that many parasitic protozoa and unicellular fungi have clo