Appl Environ Microbiol, 2000 Mar, 66(3), 1050 - 6 Reduction of Fe(III), Mn(IV), and toxic metals at 100 degrees C by Pyrobaculum islandicum; Kashefi K et al.; It has recently been noted that a diversity of hyperthermophilic microorganisms have the ability to reduce Fe(III) with hydrogen as the electron donor, but the reduction of Fe(III) or other metals by these organisms has not been previously examined in detail . When Pyrobaculum islandicum was grown at 100 degrees C in a medium with hydrogen as the electron donor and Fe(III)-citrate as the electron acceptor, the increase in cell numbers of P . islandicum per mole of Fe(III) reduced was found to be ca . 10-fold higher than previously reported . Poorly crystalline Fe(III) oxide could also serve as the electron acceptor for growth on hydrogen . The stoichiometry of hydrogen uptake and Fe(III) oxide reduction was consistent with the oxidation of 1 mol of hydrogen resulting in the reduction of 2 mol of Fe(III) . The poorly crystalline Fe(III) oxide was reduced to extracellular magnetite . P . islandicum could not effectively reduce the crystalline Fe(III) oxide minerals goethite and hematite . In addition to using hydrogen as an electron donor for Fe(III) reduction, P . islandicum grew via Fe(III) reduction in media in which peptone and yeast extract served as potential electron donors . The closely related species P . aerophilum grew via Fe(III) reduction in a similar complex medium . Cell suspensions of P . islandicum reduced the following metals with hydrogen as the electron donor: U(VI), Tc(VII), Cr(VI), Co(III), and Mn(IV) . The reduction of these metals was dependent upon the presence of cells and hydrogen . The metalloids arsenate and selenate were not reduced . U(VI) was reduced to the insoluble U(IV) mineral uraninite, which was extracellular . Tc(VII) was reduced to insoluble Tc(IV) or Tc(V) . Cr(VI) was reduced to the less toxic, less soluble Cr(III) . Co(III) was reduced to Co(II) . Mn(IV) was reduced to Mn(II) with the formation of manganese carbonate . These results demonstrate that biological reduction may contribute to the speciation of metals in hydrothermal environments and could account for such phenomena as magnetite accumulation and the formation of uranium deposits at ca . 100 degrees C . Reduction of toxic metals with hyperthermophilic microorganisms or their enzymes might be applied to the remediation of metal-contaminated waters or waste streams. Can J Microbiol, 2000 Jan, 46(1), 72 - 80 Growth kinetics of Escherichia coli with galactose and several other sugars in carbon-limited chemostat culture; Lendenmann U et al.; Kinetic models for microbial growth describe the specific growth rate (mu) as a function of the concentration of the growth-limiting nutrient (s) and a set of parameters . A typical example is the model proposed by Monod, where mu is related to s using substrate affinity (Ks) and the maximum specific growth rate (mu max) . The preferred method to determine such parameters is to grow microorganisms in continuous culture and to measure the concentration of the growth-limiting substrate as a function of the dilution rate . However, owing to the lack of analytical methods to quantify sugars in the microgram per litre range, it has not been possible to investigate the growth kinetics of Escherichia coli in chemostat culture . Using an HPLC method able to determine steady-state concentrations of reducing sugars, we previously have shown that the Monod model adequately describes glucose-limited growth of E . coli ML30 . This has not been confirmed for any other sugar . Therefore, we carried out a similar study with galactose and found steady-state concentrations between 18 and 840 micrograms.L-1 for dilution rates between 0.2 and 0.8.h-1, respectively . With these data the parameters of several models giving the specific growth rate as a function of the substrate concentration were estimated by nonlinear parameter estimation, and subsequently, the models were evaluated statistically . From all equations tested, the Monod model described the data best . The parameters for galactose utilisation were mu max = 0.75.h-1 and Ks = 67 micrograms.L-1 . The results indicated that accurate Ks values can be estimated from a limited set of steady-state data when employing mu max measured during balanced growth in batch culture . This simplified procedure was applied for maltose, ribose, and fructose . For growth of E . coli with these sugars, mu max and Ks were for maltose 0.87.h-1, 100 micrograms.L-1; for ribose 0.57.h-1, 132 micrograms.L-1, and for fructose 0.70.h-1, 125 micrograms.L-1. J Clin Microbiol, 2000 Mar, 38(3), 1085 - 93 Touchdown enzyme time release-PCR for detection and identification of Chlamydia trachomatis, C . pneumoniae, and C . psittaci using the 16S and 16S-23S spacer rRNA genes; Madico G et al.; Three touchdown enzyme time release (TETR)-PCR assays were used to amplify different DNA sequences in the variable regions of the 16S and 16S-23S spacer rRNA genes specific for Chlamydia trachomatis, Chlamydia pneumoniae, and Chlamydia psittaci as improved tests for sensitive diagnosis and rapid species differentiation . The TETR-PCR protocol used 60 cycles of amplification, which provided improved analytical sensitivity (0.004 to 0.063 inclusion-forming unit of Chlamydia species per PCR) . The sensitivity of TETR-PCR with primer set CTR 70-CTR 71 was 96.7%, and the specificity was 99.6%, compared to those of the AMPLICOR PCR for the detection of C . trachomatis in vaginal swab samples . TETR-PCR for C . pneumoniae with primer set CPN 90-CPN 91 was 90% sensitive and 93.3% specific compared with a nested PCR with primer set CP1/2-CPC/D for clinical respiratory samples . TETR-PCR for C . psittaci with primer set CPS 100-CPS 101 showed substantial agreement with cell culturing (kappa, 0.78) for animal tissue samples . Primer sets were then combined into a single multiplex TETR-PCR test . The respective 315-, 195-, and 111-bp DNA target products were precisely amplified when DNA from each of the respective Chlamydia species or combinations of them was used . Multiplex chlamydia TETR-PCR correctly identified one strain of each of the 15 serovars of C . trachomatis, 22 isolates of C . pneumoniae, and 20 isolates of C . psittaci . The primer sets were specific for each species . No target products were amplified when DNA from C . pecorum or a variety of other microorganisms was tested for specificity . TETR-PCR with primers selected for specific sequences in the 16S and 16S-23S spacer rRNA genes is a valuable test that could be used either with individual primers or in a multiplex assay for the identification and differentiation of Chlamydia species from culture isolates or for the detection of chlamydiae in clinical samples. Parassitologia, 1999 Sep, 41(1-3), 397 - 402 Pre-erythrocytic malaria vaccine: mechanisms of protective immunity and human vaccine trials; Nardin E et al.; In order to provide a rational basis for the development of a pre-erythrocytic malaria vaccine we have aimed at: (a) elucidating the mechanisms of protection, and (b) identifying vaccine formulations that best elicit protection in experimental animals and humans . Based on earlier successful immunization of experimental animals with irradiated sporozoites, human volunteers were exposed to the bites of large numbers of Plasmodium falciparum or P . vivax infected irradiated mosquitoes . The result of this vaccine trial demonstrated for the first time that a pre-erythrocytic vaccine, administered to humans, can result in their complete resistance to malaria infection . However, since infected irradiated mosquitoes are unavailable for large scale vaccination, the alternative is to develop subunit vaccines . The human trials using irradiated sporozoites provided valuable information on the human immune responses to pre-erythrocytic stages and studies on mice an excellent experimental model to characterize protective immune mechanisms . The circumsporozoite protein, the first pre-erythrocytic antigen identified, is present in all malaria species, displaying a similar structure, with a central region of repeats, and two conserved regions, essential for parasite development . Most pre-erythrocytic vaccine candidates are based on the CS protein, expressed in various cell lines, microorganisms, and recently the corresponding DNA . We and others have identified CS-specific B and T cell epitopes, recognized by the rodent and human immune systems, and used them for the development of synthetic vaccines . We used synthetic peptide vaccines, multiple antigen peptides and polyoximes, for immunization, first in experimental animals, and recently in two human safety and immunogenicity trials . We also report here on our work on T cell mediated immunity, particularly the protection of mice immunized with viral vectors expressing CS-specific cytotoxic CD8+ T cell epitopes, and the striking booster effect of recombinant vaccinia virus . To what degree CD8+ T cells, and/or other T cells specific for sporozoites and/or liver stage epitopes, contribute to pre-erythrocytic protective immunity in humans, remains to be determined. Parassitologia, 1999 Sep, 41(1-3), 159 - 62 Transmission stages of Plasmodium: does the parasite use the one same signal, provided both by the host and the vector, for gametocytogenesis and sporozoite maturation? Milon G, David PH. Among the microorganisms that strictly depend upon other organisms (hosts or vectors) for achieving their life cycle, protozoan and metazoan parasites have been often primarily distinguished through the major pathogenic processes they could induce . A variety of different mechanisms linked to parasitism can indeed systemically (e.g . Plasmodium falciparum) or locally (e.g . Toxoplasma gondii) induce important alterations of tissue homeostasis . But more than obvious pathogenicity, it is the capacity to be transmitted that is essential for parasite survival and there is increasing evidence that certain parasites can achieve their life cycle to the point of transmission in the absence of clinically detectable processes . For this, constitutive microenvironments of the host or vector can be exploited . Moreover, parasites are sometimes able to highjack effectors of the host's immune response towards conditioning the microenvironments which are permissive to differentiation of transmissible developmental stages . Based on a few examples taken from studies on the transmission stages of Leishmania, Toxoplasma and Plasmodium, we have here attempted to formulate a few hypothesis on the biology of the transmission stages of P . falciparum, i.e . on gametocytogenesis and sporozoite maturation . As discussants, we may have been somewhat dwarfed by issues evoked by the organizers of this meeting in the title of the session, i.e . 'Vector-parasite-man interactions'!.. . In reaction, we may have taken refuge in somewhat over-selective comments, biased by the objects of our personal research.... J Food Prot, 2000 Feb, 63(2), 174 - 8 Attempts to isolate Helicobacter from cattle and survival of Helicobacter pylori in beef products; Stevenson TH et al.; This study focused on important factors related to the potential of cattle and beef products to transmit Helicobacter pylori to humans . Mucosal samples were collected from the rumen and abomasum of 105 cattle and were plated on a selective medium to isolate Helicobacter spp.; none of the samples examined contained these bacteria . Studies were also conducted to determine how long H . pylori survives in refrigerated or frozen ground beef; results indicated that the microorganism dies rapidly in ground beef, whether refrigerated or frozen . Packaging in vacuum or air had little effect on survival of the organism . The number of H . pylori decreased in refrigerated samples from 3.3 log10 CFU/g on day 0 to 1.4 log10 CFU/g on day 6 . H . pylori died even more rapidly when frozen, decreasing from 3.3 log10 CFU/g on day 0 to 0.5 log10 CFU/g on day 6 . Retail beef cuts (n = 20) were also examined for the presence of H . pylori by direct plating on a selective medium and by incubation in an enriched broth followed by plating on a selective medium . None of the retail samples contained H . pylori . This research suggests that transmission of H . pylori from beef and beef products is not a primary factor in the high prevalence of this bacterium in humans. J Periodontol, 2000 Jan, 71(1), 14 - 21 Persistence patterns of Porphyromonas gingivalis, Prevotella intermedia/nigrescens, and Actinobacillus actinomyetemcomitans after mechanical therapy of periodontal disease; Mombelli A et al.; BACKGROUND: The aim of this study was to determine the distribution patterns of Porphyromonas gingivalis, Prevotella intermedia/nigrescens, and Actinobacillus actinomycetemcomitans in periodontitis patients after standard mechanical periodontal therapy, and to determine factors increasing the odds to detect these target organisms in treated sites . METHODS: Eight hundred fifty-two (852) separate subgingival microbial samples were taken from the mesial and distal aspects of every tooth in 17 patients . Target organisms were identified culturally . RESULTS: The 3 microorganisms showed different persistence patterns: P . gingivalis was detected in a high percentage of subjects (59%), but in a low proportion of sites (5.4%) . P . intermedia/nigrescens was detected in all subjects except one, and in 40.6% of the tested sites . Only 5 subjects were A . actinomycetemcomitans positive, but 2 of them showed a very high number of positive sites (44% and 75%, respectively) . A highly significant relationship was found between a subject's tendency to bleed upon sampling and the number of P . intermedia/nigrescens-positive sites . A significant portion of the variation in frequency of persisting P . gingivalis could be explained by the frequency of persisting pockets deeper than 4 mm . No similar relationship could be established between clinical parameters and A . actinomycetemcomitans . On a site level, the odds of detecting P . gingivalis increased by a factor of 2.47 (P= 0.0001) for every millimeter of residual probing depth; the odds of detecting P . intermedia/nigrescens increased by a factor of 1.84 (P= 0.0001) . CONCLUSIONS: If, after standard mechanical periodontal therapy, a large number of sites continue to bleed, one may expect an increased number of sites positive for P . intermedia/ nigrescens . If many deep pockets persist, a greater number of P . gingivalis-positive sites can be expected. J Physiol Pharmacol, 1999 Dec, 50(5), 735 - 42 The role of Helicobacter pylori in cardiovascular and cerebrovascular diseases; Gasbarrini A et al.; Classical risk factors for cardiovascular and cerebrovascular diseases do not fully coincide with the prevalence of these conditions . Emerging evidences show that new factors may be predisposing for the development of ischemic events . It has been demonstrated that atherosclerosis has a strong inflammatory background; such state of chronic inflammation may be related to the presence of persistent infectious agent . Helicobacter pylori (H . pylori), among other microorganisms, has been extensively investigated for its possible role . Many molecular mechanisms have been hypothesized to explain its eventual action . Epidemiological studies do not exclude a correlation between the infection and cardiovascular and cerebrovascular diseases . Many confounding factors, however, make difficult a definitive evaluation of the huge number of data present in the literature . Moreover, various therapeutic studies have been attempted to show if antibiotic treatment improves prognosis in patients affected by ischemic heart disease . Still, none of these trials focused specifically on the effects of H . pylori eradication on the clinical progression of vascular lesions. Trends Biochem Sci, 2000 Mar, 25(3), 138 - 43 A novel FeS cluster in Fe-only hydrogenases; Nicolet Y et al.; Many microorganisms can use molecular hydrogen as a source of electrons or generate it by reducing protons . These reactions are catalysed by metalloenzymes of two types: NiFe and Fe-only hydrogenases . Here, we review recent structural results concerning the latter, putting special emphasis on the characteristics of the active site. Proc Natl Acad Sci U S A, 2000 Mar 14, 97(6), 2486 - 90 Biosynthesis of terpenoids: YgbB protein converts 4-diphosphocytidyl-2C-methyl-D-erythritol 2-phosphate to 2C-methyl-D-erythritol 2,4-cyclodiphosphate; Herz S et al.; In many microorganisms, the putative orthologs of the Escherichia coli ygbB gene are tightly linked or fused to putative orthologs of ygbP, which has been shown earlier to be involved in terpenoid biosynthesis . The ygbB gene of E . coli was expressed in a recombinant E . coli strain and was shown to direct the synthesis of a soluble, 17-kDa polypeptide . The recombinant protein was found to convert 4-diphosphocytidyl-2C-methyl-D-erythritol 2-phosphate into 2C-methyl-D-erythritol 2,4-cyclodiphosphate and CMP . The structure of the reaction product was established by NMR spectroscopy using (13)C-labeled substrate samples . The enzyme-catalyzed reaction requires Mn(2+) or Mg(2+) but no other cofactors . Radioactivity from {2-(14)C}2C-methyl-D-erythritol 2,4-cyclodiphosphate was diverted efficiently to carotenoids by isolated chromoplasts from Capsicum annuum and, thus, was established as an intermediate in the deoxyxylulose phosphate pathway of isoprenoid biosynthesis . YgbB protein also was found to convert 4-diphosphocytidyl-2C-methyl-D-erythritol into 2C-methyl-D-erythritol 3,4-cyclophosphate . This compound does not serve as substrate for the formation of carotenoids by isolated chromoplasts and is assumed to be an in vitro product without metabolic relevance. Biochem Biophys Res Commun, 2000 Mar 5, 269(1), 290 - 5 Identification of benzodiazepines in Artemisia dracunculus and Solanum tuberosum rationalizing their endogenous formation in plant tissue; Kavvadias D et al.; Sterile cultivated plant cell tissues and cell regenerates of several species were tested for their binding affinity to the central human benzodiazepine receptor . Binding activity was found in extracts of Artemisia dracunculus cell tissue (IC(50) = 7 microg/ml) and, to a lesser extent, in plant regenerates of potato herb (Solanum tuberosum) . Preparative HPLC led to the isolation of fractions with a significant displacing potency in the benzodiazepine receptor binding assay . Using on-line HPLC-electrospray-tandem mass spectrometry (HPLC-ESI-MS/MS) in the "selected reaction monitoring" (SRM) mode, delorazepam and temazepam were found in amounts of about 100 to 200 ng/g cell tissue of Artemisia dracunculus, whereas sterile potato herb contained temazepam and diazepam ranging approximately from 70 to 450 ng/g cell tissue . It is the first report on the endogenous formation of benzodiazepines by plant cells, as any interaction of microorganisms and environmental factors was excluded . Stomatologiia (Mosk), 2000, 79(1), 13 - 6 {The evaluation of periodontal status by the chemical composition of the oral media}; Volozhin AI et al.; Twelve patients aged 21-38 years with gingivitis and periodontitis and 9 subjects with intact periodontium were examined . Air from the oral cavity was collected with a special device, liquid samples were collected by gargling with sterile water . Chemical composition of the air and washings was analyzed by chromato-mass-spectrometry, gas adsorption and gas liquid chromatography . Inflammation of periodontal tissues was associated with a sharp increase in the oral air concentration of methylethylketone . The concentrations of isovaleric, n-valeric, and n-enanthic aldehydes increased appreciably . Ethanol predominated over n-butyl alcohol . The levels of dimethylsulfide and isoprene increased several times . In the washings from the oral cavity, the content of microorganism's vital activity products (fatty acids) was increased . Possible metabolic mechanisms of the detected shifts are discussed. J Immunol, 2000 Mar 1, 164(5), 2610 - 8 Purification and characterization of two mannan-binding lectins from mouse serum; Hansen S et al.; Mannan-binding lectin (MBL) is a serum protein that activates the complement system after binding to glycoconjugates found on the surface of microorganisms . By molecular cloning two forms of MBL have been identified in the mouse (mMBL-A and mMBL-C), but only mMBL-A has been purified and characterized at the protein level . MBL-C has been termed the liver form of MBL . The present report describes the purification and characterization of mMBL-A and mMBL-C from serum . The two forms of mMBL could be separated both by ion-exchange and carbohydrate-affinity chromatography . The initial identification by immunochemical technique was confirmed by N-terminal amino-acid sequencing . Both proteins give bands corresponding to polypeptide chains of 28 kDa on SDS-PAGE in the reduced state, but mMBL-A migrated more rapidly than mMBL-C in acid/urea-PAGE, in accordance with the calculated pIs . Both forms mediated activation of complement component C4 in mannan-coated microtiter wells . MBL-A showed a higher affinity for d -glucose and alpha-methyl-d -glucose then did MBL-C . Serum concentrations of mMBL-A in laboratory strains and wild mice were found to vary from 5 to 80 microg/ml, with wild mice tending to show higher levels than laboratory strains. J Cutan Med Surg, 2000 Jan, 4(1), 30 - 5 Lichen planopilaris-like changes arising within an epidermal nevus: does this case suggest clues to the etiology of lichen planopilaris? Smith KJ, Crittenden J, Skelton H. BACKGROUND: Lichen planopilaris shows a perifollicular lymphocytic infiltrate at the level of infundibulum and the isthmus of the hair bulge resulting in necrotic changes within keratinocytes and eventually hair loss . OBJECTIVE: We present a 14-year-old black male with a history of a raised epidermal lesion on the scalp that was present at birth . Over the past few years, the patient developed gradual hair loss and increased verrucous changes of the skin within the original lesion . Histologic sections of the area showed features consistent with an epidermal nevus peripherally, with a central area showing some features characteristic of those seen in lichen planopilaris . In addition, there was marked hyperkeratosis with increased yeast and bacteria within the follicles . CONCLUSIONS: Initiating factors in lichen planopilaris are not well defined . Overgrowth of microorganisms with hyperkeratosis results in factors that disrupt the immune privilege of the hair follicle, leading to an immunologic reaction that is limited to the follicle and spares surrounding eccrine structures . This case suggests possible mechanisms involved in the induction of lichen planopilaris. Gene, 2000 Feb 22, 244(1-2), 47 - 54 Mammalian genomes contain active recombinase recognition sites; Thyagarajan B et al.; Recombinases derived from microorganisms mediate efficient site-specific recombination . For example, the Cre recombinase from bacteriophage P1 efficiently carries out recombination at its loxP target sites . While this enzyme can function in mammalian cells, the 34bp loxP site is expected to be absent from mammalian genomes . We have discovered that sequences from the human and mouse genomes surprisingly divergent from loxP can support Cre-mediated recombination at up to 100% of the efficiency of the native loxP site in bacterial assays . Transient assays in human cells demonstrate that such pseudo-lox sites also support Cre-mediated integration and excision in the human cell environment . Pseudo sites for Cre and other recombinases may be useful for site-specific insertion of exogenous genes into mammalian genomes during gene therapy and other genetic engineering processes. Gen Dent, 1999 Nov-Dec, 47(6), 572 - 5 The oral implications of Hodgkin's disease; Herrin HK; Hodgkin's disease is a cancer involving the lymphatics . While the yearly total of new cases is only approximately 7,500, the disease is very curable with modern radiotherapy and/or combination chemotherapy . This represents an increasing number of survivors who require dental treatment . Unfortunately, the treatment for Hodgkin's results in significant, permanent complications that persist for the duration of the patient's life . These complications can include xerostomia, radiation-induced caries, the risk of osteoradionecrosis in irradiated bone, and systemic complications such as a reduced immune response to microorganisms . These patients can and do undergo all types of dental treatment safely as long as the practitioner recognizes the risks involved and takes appropriate precautions. Hum Pathol, 2000 Feb, 31(2), 263 - 8 Eradication of Borrelia burgdorferi infection in primary marginal zone B-cell lymphoma of the skin; Roggero E et al.; Primary cutaneous B-cell lymphomas have been associated with Borrelia burgdorferi, the spirochete responsible for Lyme disease . Recently, cutaneous marginal zone B-cell lymphoma has been proposed as a distinct clinical-pathological entity . We report a case of primary cutaneous marginal zone lymphoma, associated with B burgdorferi infection . Polymerase chain reaction (PCR) amplification of the third complementarity determining region (CDR3) of the immunoglobulin heavy chain gene showed the presence of a monoclonal lymphoproliferation, therefore strengthening the histological diagnosis of a malignant process . B burgdorfer-specific hbb gene sequences were detected by PCR in the lymphoma tissue at diagnosis but not after antibiotic treatment . A nearly complete clinical and histological regression was observed after B burgdorferi eradication, with immunohistochemistry studies showing disappearance of plasma cell differentiation and a marked decline in the number of CD3+ T cells and Ki-67+ cells . Our case confirms the link between B burgdorferi and some cutaneous lymphomas . The disappearance of the microorganism accompanied by the unequivocal decrease of most indicators of active T- and B-cell immune response strongly supported a pathogenetic role for B burgdorferi in sustaining an antigen-driven development and growth of this cutaneous marginal zone lymphoma . Antibiotic therapy (analogous to Helicobacter pylori infection in gastric MALT lymphoma) might be helpful with the aim of averting or at least deferring the indication for more aggressive treatment. Int J Immunopharmacol, 2000 Mar, 22(3), 237 - 46 Aflatoxin B(1) inhibits CD14-mediated nitric oxide production in murine peritoneal macrophages; Moon EY et al.; Aflatoxin B(1) (AFB(1)), a potent hepatocarcinogen, has been known to impair non-specific and specific immunity . Macrophages play an important role in host defense against tumors and microorganisms and a number of compounds are implicated in macrophage cytotoxicity . Since activated by the reaction of LPS with CD14, macrophages produce nitric oxide (NO) that is a cytotoxic effector molecule in cell killing . In the present study, we investigated whether the alteration of CD14 level on macrophages by AFB(1) affects NO production in murine peritoneal macrophages . When macrophages were stimulated with LPS after AFB(1)-pretreatment, or they were co-treated with LPS and AFB(1), the NO production decreased in a dose-dependent manner . In contrast, when macrophages were post-treated with AFB(1) after LPS-stimulation, NO production was unchanged . DNA, RNA, and protein synthesis were reduced by AFB(1)-pretreatment of macrophages . The addition of anti-CD14 antibodies to the cultures decreased NO production further . FACS analysis showed that the binding of anti-CD14 antibodies to the macrophages was suppressed by AFB(1)-pretreatment followed by LPS-stimulation . However, AFB(1) does not alter the binding anti-CD14 antibodies to the macrophages without LPS-stimulation . In contrast, AFB(1) pretreatment increased an amount of CD14 released in culture medium . Taken together, these data indicate that the reduced NO production in murine peritoneal macrophages by AFB(1)-pretreatment is related to the suppressed expression of CD14 on macrophage membrane and to the increased secretion of it to culture medium after LPS-stimulation. Bioessays, 2000 Mar, 22(3), 255 - 63 Phagosome dynamics and function; Tjelle TE et al.; Phagocytosis of microorganisms and other particles is mediated most efficiently by receptors such as Fc-receptors (FcR) and complement-receptors (C3R) . Interaction between these receptors and ligands on the particle results in signal transduction events that lead to actin polymerisation and phagosome formation . The phagosome then undergoes a maturation process whereby it transforms into a phagolysosome . Phagosome maturation depends on interactions (fusion events) with early and late endosomes as well as with lysosomes . The fusion processes are regulated by small GTP-binding proteins and other proteins that are also involved in fusion processes in the endocytic pathway . Although most phagocytosed microorganisms are killed in the lysosome, some pathogens have developed survival strategies and are able to live in the harsh conditions in the phagolysosome or interfere with the maturation process and thereby evade destruction by acid hydrolases . Hua Xi Yi Ke Da Xue Xue Bao, 1997 Jun, 28(2), 122 - 7 {Immunogenecity of expressed protein p68 from recombinant plasmid rpDJt in L . interrogans serovar lai}; Jiang N et al.; There are two types of infection caused by pathogenic microorganisms, intracellular infection and intercellular infection . Infection of pathogenic leptospira is an intercellular infection . The immunological reaction of host to intercellular infection is unique . The potential immunogen of an expressed protein should meet three criteria: it can be degraded (by antigen-present cells in the host); it should have antigenic epitope which can be recognized by specific antibodies and have at least one epitope that can be recognized by an MHC II protein and T cell receptor . In this study we report the cloning of an L . interrogans protein in plasmid rpDJt and the immunogencity of the expressed protein derivative . A genomic library of L . interrogans serovar lai strain 017 was constructed with the plasmid vector pUC18 . Recombinant plasmids, designated pDJH2 and pDJ8 were screened from the bank . EcoRI-inserted fragment of 1 . 9 kb recombinant DNA of pDJH2 was ligated into T7 RNA polymerase/promoter vectors (pT7-7) . Then they were transformed into E . coli JM109 (De3), one of subclones, designated rpDJt was achieved . SDS-PAGE showed that the molecular weights of expression proteins were 68 kd and 23 kd respectively, designated p68 and p23 . Purifying and isolating p68 and p23, we separated them from SDS-Polyacrylamide gels by using Side-Strip method . After fragmenting and electroeluting, p68 and p23 were injected into guinea pigs and rabbits . An extremely strong immune response to p68 was obtained since an anti-p68 antibody response could be detected to a dilution 1:524,288 (guinea pigs) and 1:262,144 (rabbits) by ELISA while anti-P23 antibody being 1:1024 (the same to guinea pigs and rabbits) . The results of improved MTT and conA 3HTdR transformation methods showed the activities and proliferation of Th-cells were increased in guinea pigs after p68 immunization (IL-6, 83.25 IU/ml, IL-2, 28.75 IU/ml; RPI, 2.04, SI, 65.62%) Thlymphocyte existed in two subclasses, the Th1- and Th2-cells . A major role of Th2-cells is to "help" B-cells differentiate, replicate, and secrete antibody . The properties of these interactions explain why p68 makes good antigen and p23 does not . The antigens responsible for eliciting the production of protective antibodies are not known; however, several outer membrane proteins on L . interrogans are candidates for vaccine . Our results suggest that expresion protein p68 from recombinants (rpDJt) may be a candidate for gene engineered subunit vaccine for Leptospirosis. Virology, 2000 Mar 1, 268(1), 122 - 31 Limitations of in vivo IL-12 supplementation strategies to induce Th1 early life responses to model viral and bacterial vaccine antigens; Kovarik J et al.; The limited induction of Th1 and cytotoxic immune responses is regarded as the main reason for the increased susceptibility to intracellular microorganisms in early life . Recently, in vitro IL-12 supplementation was shown to enhance the limited IFN-gamma release of measles-specific infant T cells . Using a series of IL-12 delivery systems, we show here that in vivo IL-12 supplementation may enhance early life murine Th1 responses to two model vaccine antigens, measles virus hemagglutinin and tetanus toxin peptide . However, this required multiple repeat injections of recombinant rIL-12, which were poorly tolerated in young mice . Local IL-12 delivery by an IL-12 expressing canarypox vector proved safe but failed to modulate vaccine responses . An IL-12 DNA plasmid or a CD40L DNA plasmid efficiently enhanced neonatal Th1 responses to measles hemagglutinin DNA vaccine . However, both plasmids only enhanced Th1 responses to DNA and not to peptide, protein, or live viral vaccines . Thus, inducing adult-like Th1 responses may be achieved in vivo by inducing (CD40L) or substituting for (IL-12 supplementation) optimal activation of neonatal APC . However, these immunomodulatory effects appear limited to certain antigen-presentation approaches and may not be broadly applicable to vaccines . J Biotechnol, 2000 Feb 17, 77(2-3), 247 - 53 Calorimetrically recognized maximum yield of poly-3-hydroxybutyrate (PHB) continuously synthesized from toxic substrates; Maskow T et al.; The broader usage of poly-beta-hydroxybutyrate (PHB), for instance as bulk plastics, calls for cheap raw materials and greater overall process efficiency . The bacterial synthesis is generally induced and promoted by the limitation of growth via nitrogen, oxygen or phosphate depletion with the simultaneous excess and higher concentration of the carbon substrate . Consequently, toxic substrates have been considered unsuitable for PHB synthesis . Nevertheless, a single-stage continuous process for producing PHB from toxic substrates using microorganisms was developed and is reported here . The maximum heat flux during continuous growth and the maximum yield of PHB versus the substrate consumption rate were found to coincide . This suggests the possibility of controlling the conversion of a growth-inhibiting substrate into PHB and maximizing the process efficiency . The observed correlation occurred irrespective of the substrates investigated (phenol or sodium benzoate), the PHB-producing strain (Ralstonia eutropha JMP 134 or Variovorax paradoxus JMP 116), or the type of limitation imposed . The maximum PHB yields obtained comprised up to 50% of cell dry mass. Phytochemistry, 2000 Jan, 53(2), 161 - 76 Phytoalexins from crucifers: synthesis, biosynthesis, and biotransformation; Pedras MS et al.; Phytoalexins play a significant role in the defense response of plants . These secondary metabolites, which are synthesized de novo in response to diverse forms of stress, including fungal infection, are part of the plants' chemical and biochemical defense mechanisms . Phytoalexins from crucifers are structurally and biogenetically related, but display significantly different biological activities . Here, we review work reporting the chemical structures, synthesis, biosynthesis and metabolism of cruciferous phytoalexins, as well as their biological activity towards different microorganisms. Curr Opin Immunol, 2000 Feb, 12(1), 44 - 51 Human complement regulators: a major target for pathogenic microorganisms; Lindahl G et al.; The C3 convertases of the human complement system are controlled by fluid-phase and membrane proteins in the RCA (regulators of complement activation) family . Accumulated data show that many pathogenic microorganisms interact with these complement regulators . Recent advances in this field include determination of the crystal structure of the binding domains in the measles virus receptor CD46 and identification of a CD46 transgenic mouse line that is sensitive to measles virus . Moreover, recent findings support the hypothesis that pathogenic bacteria binding fluid-phase RCA proteins exploit these proteins to escape complement attack . These studies provide novel insight into the interplay between pathogens and the innate immune system and may have implications for the plans to use animals expressing an RCA protein for xenotransplantation. Trends Cell Biol, 2000 Mar, 10(3), 85 - 8 Regulation of endocytic traffic by rho family GTPases; Ellis S et al.; Endocytosis is a complicated yet highly efficient process that involves the uptake and processing of cargoes, ranging from small molecules, to activated signalling receptors, to whole microorganisms . Regulation of endocytic pathways is poorly understood . Recent evidence suggests that the Rho GTPase family of signalling proteins is intimately involved in endocytic traffic, providing novel insights into the control mechanisms that govern this process. J Chromatogr A, 1999 Dec 31, 865(1-2), 129 - 44 Expanded-bed chromatography in primary protein purification; Anspach FB et al.; Chromatography in stable expanded beds enables proteins to be recovered directly from cultivations of microorganisms or cells and preparations of disrupted cells, without the need for prior removal of suspended solids . The general performance of an expanded bed is comparable to a packed bed owing to reduced mixing of the adsorbent particles in the column . However, optimal operating conditions are more restricted than in a packed bed due to the dependence of bed expansion on the size and density of the adsorbent particles as well as the viscosity and density of the feedstock . The feedstock composition may become the most limiting restriction owing to interactions of adsorbent particles with cell surfaces, DNA and other substances, leading to their aggregation and consequently to bed instabilities and channeling . Despite these difficulties, expanded-bed chromatography has found widespread applications in the large scale purification of proteins from mammalian cell and microbial feedstocks in industrial bioprocessing . The basics and implementation of expanded-bed chromatography, its advantages as well as problems encountered in the use of this technique for the direct extraction of proteins from unclarified feedstocks are addressed. Pediatr Res, 2000 Feb, 47(2), 225 - 32 Detection of microorganisms in the tracheal aspirates of preterm infants by polymerase chain reaction: association of adenovirus infection with bronchopulmonary dysplasia; Couroucli XI et al.; Bronchopulmonary dysplasia (BPD) is recognized as an important cause of morbidity and mortality in preterm infants . Because the role of congenital infections in BPD has been debated, the purpose of this study was to test the hypothesis that detection of infectious agents in tracheal aspirate samples was associated with the development of BPD . Tracheal aspirate samples were obtained within the 1st week of life and screened by polymerase chain reaction for adenovirus, cytomegalovirus, parvovirus, enteroviruses, Ureaplasma urealyticum, Mycoplasma hominis, Mycoplasma pneumoniae, and Chlamydia species . BPD was defined as persistent oxygen dependence at 28 d of age and 36 wk postconceptional age (PCA) . Infants that expired before these time points were excluded from statistical analysis . Out of 89 infants studied, at 28 d of life, 13 had expired, 45 had BPD, and 31 had no BPD (controls) . At 36 wk PCA, 15 infants expired, 39 still had BPD, and 35 did not . A significant increase in the frequency of adenovirus genome was identified in BPD patients compared with controls, both at 28 d of life (12/45 = 27% versus 1/31 = 3%: p< or =0.01) and at 36 wk PCA (10/39 = 29% versus 2/35 = 6%: p = 0.01) . Other microorganisms were rarely detected and not associated with the development of BPD . This is the first study reporting the frequency of detection of adenovirus DNA in tracheal aspirate samples obtained during the 1st week of life from infants with BPD and suggests that prenatal acquisition may be important in the development of BPD. Rev Environ Health, 1999 Jul-Sep, 14(3), 159 - 68 Indoor allergen exposure in west and East Germany: a cause for different prevalences of asthma and atopy? Hirsch T. West and East Germans have been living in two different political systems for 40 years . These two populations have become a classic epidemiological example for the hypothesis that lifestyle changes accompanying the industrial and economic development of modern societies are responsible for an increase in the prevalence of atopic diseases . A higher prevalence of atopic sensitization, asthma, and hay fever was found in young West Germans after the unification . It has been hypothesized that this phenomenon was at least partially due to the installation of insulating windows and central heating systems in Western homes, favoring the growth of microorganisms like mites and moulds and increasing indoor allergen exposure . This review summarizes studies that have investigated reservoir concentrations of indoor allergens in public buildings and private homes in East and West Germany . Whereas a higher prevalence of atopic sensitization in West Germans was found for nearly all tested allergens (cat, mite, pollen), allergen exposure was higher only for cat allergens, but probably not for mite and cockroach allergens or moulds . The published data do not support the view that the differences in specific sensitization are caused by differences in the exposure to specific allergens. Structure Fold Des, 2000 Feb 15, 8(2), 111 - 22 Structure of Aspergillus niger epoxide hydrolase at 1.8 A resolution: implications for the structure and function of the mammalian microsomal class of epoxide hydrolases; Zou J et al.; Background: Epoxide hydrolases have important roles in the defense of cells against potentially harmful epoxides . Conversion of epoxides into less toxic and more easily excreted diols is a universally successful strategy . A number of microorganisms employ the same chemistry to process epoxides for use as carbon sources . Results: The X-ray structure of the epoxide hydrolase from Aspergillus niger was determined at 3.5 A resolution using the multiwavelength anomalous dispersion (MAD) method, and then refined at 1.8 A resolution . There is a dimer consisting of two 44 kDa subunits in the asymmetric unit . Each subunit consists of an alpha/beta hydrolase fold, and a primarily helical lid over the active site . The dimer interface includes lid-lid interactions as well as contributions from an N-terminal meander . The active site contains a classical catalytic triad, and two tyrosines and a glutamic acid residue that are likely to assist in catalysis . Conclusions: The Aspergillus enzyme provides the first structure of an epoxide hydrolase with strong relationships to the most important enzyme of human epoxide metabolism, the microsomal epoxide hydrolase . Differences in active-site residues, especially in components that assist in epoxide ring opening and hydrolysis of the enzyme-substrate intermediate, might explain why the fungal enzyme attains the greater speeds necessary for an effective metabolic enzyme . The N-terminal domain that is characteristic of microsomal epoxide hydrolases corresponds to a meander that is critical for dimer formation in the Aspergillus enzyme. Res Microbiol, 1999 Nov-Dec, 150(9-10), 579 - 87 Characteristics of Chi distribution on different bacterial genomes; El Karoui M et al.; The availability of full genome sequences provides the bases for analyzing global properties of the genetic text . For example, oligonucleotide sequences that are over- or underrepresented can be identified by taking into account the overall genome composition and organization . One of the most overrepresented oligonucleotides in Escherichia coli is the Chi site, an octanucleotide that stimulates DNA repair by homologous recombination . Here we analyze the genomic distribution of Chi in E . coli and in the three other bacteria where a Chi sequence has been identified; note that Chi is a different sequence in each organism . For each bacterial genome, Chi sequences are frequent, regularly distributed, and overrepresented . This suggests that selection for Chi may have occurred during evolution to favor efficient repair of a damaged chromosome . Other characteristics of Chi distribution are not conserved and might reflect specific features of DNA repair in each host . The different sequence and characteristics of Chi in each microorganism suggest that selection for Chi occurred independently in different bacteria. J Photochem Photobiol B, 1999 Nov-Dec, 53(1-3), 1 - 6 Measurement of UV radiation using suspensions of microorganisms; Sommer R et al.; The measurement of solar UV radiation is usually performed using physical devices like photodiodes or photomultipliers or with chemical substances (actinometry) . The application of biological material such as microorganisms for this purpose has gained increasing importance in the last few years . The microorganisms may be dried and spread on a flat surface or they may be in aqueous suspensions contained in UV-transparent vessels . If the measurements are done on flat surfaces, the irradiance weighted by the action spectrum of the dried microorganism used is the result of the measurement . If aqueous suspensions of microorganisms are used, contained for instance in spherical vessels, the fluence weighted by the action spectrum of the microorganisms in the aqueous suspension is the result . A problem of this method of measurement can be that inside the vessel the distribution of UV radiation is usually not homogeneous, causing distributions of fluences among the irradiated microorganisms, which may result in variation of the results depending on the mixing characteristics of the suspension during irradiation. Am J Epidemiol, 2000 Feb 1, 151(3), 324 - 34 Genetic distances for the study of infectious disease epidemiology; Salamon H et al.; Molecular epidemiologic studies of infectious pathogens 1) generate genetic patterns from a collection of microorganisms, 2) compare the degree of similarity among these patterns, and 3) infer from these similarities infectious disease transmission patterns . The authors propose a quantitative approach using genetic distances to study the degree of similarity between patterns . Benefits of such genetic distance calculations are illustrated by an analysis of standard DNA fingerprints of Mycobacterium tuberculosis in San Francisco collected during the period 1991-1997 . Graphical representation of genetic distances can assist in determining if the disappearance of a specific pattern in a community is due to interruption of transmission or ongoing evolution of the microorganism's fingerprint . Genetic distances can also compensate for varying information content derived by DNA fingerprints of contrasting pattern complexity . To study demographic and clinical correlates of transmission, the authors calculated the smallest genetic distance from each patient sample to all other samples . With correlation of genetic distances and nearest genetic distances with previously understood notions of the epidemiology of M . tuberculosis in San Francisco, factors influencing transmission are investigated. Zentralbl Chir, 1999, 124 Suppl 4, 1 - 8 {General infection prevention in abdominal surgery with special reference to intestinal decontamination}; Schardey HM; In surgery prophylaxis for infection is necessary, because patients are immunocompromised due to the underlying disease and the operation while at the same time being increasingly exposed to potentially pathogenic germs . Prophylaxis is based on the control of endogenous and exogenous microorganisms . For this purpose either systemic or locally active topical agents may be employed . Systemically active substances are applied with the aim to kill and eliminate invasive microorganisms in deep tissue levels, either by their own biological activity or by stimulating specific or unspecific host immune reactions . Local topical measures in contrast are to prevent the primary contact between microorganisms and host . The central pillar of systemic measures is the perioperative systemic antibiotic prophylaxis, immunonutrition is beginning to gain importance, and in the future possibly substances such as G-CSF, which directly stimulate the immune system, may be employed . Standard topical measures are sterilization and desinfection while decontamination of the digestive tract has until now not found a wide spread acceptance . For certain indications especially high risk surgical resections with anastomoses at the level of the oesophagus or the lower rectum it is possible to eliminate endogenous intestinal microorganisms effectively using topical decontamination in combination with systemic antibiotics and improve the surgical results, especially anastomotic healing. Jpn J Pharmacol, 1999 Dec, 81(4), 317 - 23 Evaluation of NOx in the cardiovascular system: relationship to NO-related compounds in vivo; Ishibashi T et al.; Diverse attention should be paid to evaluating NOx (NO2- and NO3-) in plasma as an index of endothelial nitric oxide (NO) formation in vivo . Nitric oxide, which subsequently appears as NOx, originates from different types of NO synthase and from nonenzymatic reactions . NOx also comes from exogenous sources such as food and gastrointestinal microorganisms . The fate of the NO incorporated into activation of guanylate cyclase, formation of nitrosyl hemoglobin (or nitrosohemoglobin), nitrosothiols, peroxynitrite and its derivatives and other possible compounds is not clear at present . However, some of these compounds would produce NOx as by-products or as final products through metabolism . Therefore, plasma NOx contains information about these pathways, although how extensively these factors contribute to plasma NOx has not been quantitatively defined . A theoretical simulation of NOx in the systemic circulation indicates that only small changes are expected by inhibition or stimulation of endothelial NO production . Measuring NOx production during coronary circulation has the advantage that some degree of NOx accumulation is expected from intact endothelial cells because an excretion system is absent in the heart. Invest Clin, 1999 Dec, 40(4), 277 - 300 {The NADPH-oxidase complex in chronic granulomatous disease: preliminary description of a cluster in Mérida-Venezuela}; Salmen S et al.; Chronic Granulomatous Disease (CGD) is a primary immunodeficiency characterized by an unusual predisposition to develop bacterial and fungal infections due to a failure of phagocytic leukocytes to generate superoxide, required for the intracellular killing of microorganisms . The lack of superoxide production is secondary to a defect in the NADPH-oxidase enzymatic complex activation, as a result of mutations of any of the components . Both, X-linked and autosomal recessive patterns of inheritance have been demonstrated in this disease, being the X-linked the most frequent and characterized by mutations in gp91phox . Mutations in p47phox, p67phox and p22phox have been shown in the autosomal recessive pattern . The molecular and genetic characteristic of NADPH-oxidase complex and its pathology in CGD are reviewed along with a brief description of the preliminary findings in two families from Merida, Venezuela. Orig Life Evol Biosph, 1999 Dec, 29(6), 625 - 31 Did Viking discover life on Mars? Klein HP. A major argument in the claim that life had been discovered during the Viking mission to Mars is that the results obtained in the Labeled Release (LR) experiment are analogous to those observed with terrestrial microorganisms . This assertion is critically examined and found to be implausible. HNO, 2000 Feb, 48(2), 147 - 51 {Herpes simplex virus type 1-induced rising dbl quote, left (low)tumor" in the nasal vestibule . The problem of resistance development of herpes simplex in a patient with chronic lymphatic B-cell leukemia}; Althof F et al.; Herpes simplex viruses are known to be among the most common disease-causing microorganisms . Their prevalence can exceed 90% depending on the socioeconomic status of the population . Since the number of immunocompromised patients has increased because of the increased incidence in the acquired immunodeficiency syndrome and an increase in organ transplantation, herpes virus infection may have a greater clinical significance . While treatment of otherwise healthy individuals will not usually cause any clinical problems herpes infection in an immunocompromised patient can have severe consequences . Additionally, development of viral resistance can be observed that may require alternative drugs in treatment . We present a case history of a man with a B-cell chronic lymphocytic leukemia that was associated with a very unusual herpes simplex virus infection in the nasal vestibule . Possible causes for the development of resistance in herpes infections and the use of famciclovir and forscarnet as two therapeutic alternatives to aciclovir are discussed. Trends Microbiol, 2000 Feb, 8(2), 68 - 73 New perspectives on nitrogen-fixing microorganisms in tropical and subtropical oceans; Zehr JP et al.; New molecular and microscopic evidence indicates that the open ocean harbors a diverse range of novel free-living and symbiotic nitrogen-fixing microorganisms . Although the extent to which these microorganisms fix nitrogen is currently unclear, ongoing research indicates that they might make a substantial contribution to the open ocean nitrogen budget. J Biol Chem, 2000 Feb 11, 275(6), 3977 - 83 The multiple activities of polyphosphate kinase of Escherichia coli and their subunit structure determined by radiation target analysis; Tzeng CM et al.; Polyphosphate kinase (PPK), the principal enzyme required for the synthesis of inorganic polyphosphate (polyP) from ATP, also exhibits other enzymatic activities, which differ significantly in their biochemical optima and responses to chemical agents . These several activities include: polyP synthesis (forward reaction), nATP --> polyP(n) + nADP (Equation 1); ATP synthesis from polyP (reverse reaction), ADP + polyP(n) --> ATP + polyP(n - 1) (Equation 2); general nucleoside-diphosphate kinase, GDP + polyP(n) --> GTP + polyP(n - 1) (Equation 3); linear guanosine 5'-tetraphosphate (ppppG) synthesis, GDP + polyP(n) --> ppppG + polyP(n - 2) (Equation 4); and autophosphorylation, PPK + ATP --> PPK-P + ADP (Equation 5) . The Mg(2+) optima are 5, 2, 1, and 0.2 mM, respectively, for the activities in Equations 1, 2, 3, and 4 . Inorganic pyrophosphate inhibits the activities in Equations 1 and 3 but stimulates that in Equation 4 . The kinetics of the activities in Equations 1, 2, and 3 are highly processive, whereas the transfer of a pyrophosphoryl group from polyP to GDP (Equation 4) is distributive and demonstrates a rapid equilibrium, random Bi-Bi catalytic mechanism . Radiation target analysis revealed that the principal functional unit of the homotetrameric PPK is a dimer . Exceptions are a trimer for the synthesis of ppppG (Equation 4) and a tetrameric state for the autophosphorylation of PPK (Equation 5) at low ATP concentrations . Thus, the diverse functions of this enzyme involve different subunit organizations and conformations . The highly conserved homology of PPK among 18 microorganisms was used to determine important residues and conserved regions by alanine substitution, by site-directed mutagenesis, and by deletion mutagenesis . Of 46 single-site mutants, seven exhibit none of the five enzymatic activities; in one mutant, ATP synthesis from polyP is reduced relative to GTP synthesis . Among deletion mutants, some lost all five PPK activities, but others retained partial activity for some reactions but not for others. Caring, 1999 Nov, 18(11), 6 - 11 Preventing and controlling the transmission of antibiotic-resistant microorganisms in the home care setting; Friedman MM; Antibiotic-resistant microorganisms can spread to other home care patients by an infected or colonized patient receiving home care services and the home care staff member unknowingly carrying it to another home care patient's home . Controlling the transmission of antibiotic-resistant microorganisms is the primary responsibility of those providing direct patient care . The ultimate goal for home care is to prevent staff colonization and cross-contamination to other home care patients. Semin Thorac Cardiovasc Surg, 1999 Oct, 11(4 Suppl 1), 157 - 62 The Toronto SPV bioprosthesis: review of morphological findings in eight valves; Butany J et al.; The morphological findings in eight explanted Toronto SPV bioprostheses were described . Clinical records were reviewed for patient information and data regarding the explanted bioprosthesis, all of which were analyzed in detail by gross and histological examination . All valves were also examined radiologically and detailed specimen photographs obtained . When warranted, tissue cultures were taken and special stains for microorganisms obtained . The Toronto SPV bioprosthesis has been used for aortic valve replacement in 270 patients since its introduction in 1991 . The follow-up evaluation was 99.5% complete . Eight valves have been explanted: three at surgery and five at autopsy . Patient age ranged from 35 to 69 years, with five male and three female patients . Indications for aortic valve replacement were aortic stenosis in all cases . Implant duration ranged from 5 weeks to just over 6 years (mean 38 months) . Early failures (2) were due to infective endocarditis . Two patients died of acute myocardial infarction, related to pre-existing coronary artery disease, and two died from lung cancer . All late explants showed host tissue growth (grade 2-3), with variable extension onto both the proximal and distal suture lines, as well as extension onto the cusps and commissures on the flow and nonflow surfaces . Extension of pannus onto native aortic tissues was seen but did not encroach on the coronary ostia . Tissue degenerative changes were present, as were small tears (type 1) in two valves . Mild calcification was seen in two valves . The Toronto SPV has excellent clinical performance at up to 8 years of follow-up evaluation . In this series, early failures are related to infective endocarditis, and later explants (6 of 8) are associated with mild tissue degeneration and an occasional cusp tear . At up to 5 years, only minimal/mild calcification was seen in two of the eight valves. Adv Exp Med Biol, 1999, 473, 319 - 37 New approaches to mucosal immunization; Cardenas-Freytag L et al.; Every year more than 17 million deaths worldwide are caused by infectious diseases . The great majority of these deaths occur in underdeveloped countries and are attributed to diseases preventable by existing vaccines, or diseases that could potentially be prevented with new vaccines . The fact that most human and veterinary pathogens establish infection in the host by initiating contact at a mucosal surface, provide the rationale for the development of mucosal vaccines . An increasing number of strategies have been proposed to facilitate mucosal immunization . Among the most widely investigated strategies are the use of attenuated microorganisms; the inclusion of immunizing antigens in lipid-based carriers, the genetic creation of transgenic plants and the use of mucosal adjuvants derived from bacterial toxins . This review provides a brief summary of the most recent advances in the field of mucosal immunization with an special emphasis on a promising genetically detoxified mucosal adjuvant, LT(R192G), derived from the heat-labile toxin of enterotoxigenic E . coli . We present evidence regarding the safety, immunogenicity, and efficacy of LT(R192G) for the development of a new generation of mucosal vaccines. J Immunol, 2000 Feb 15, 164(4), 2193 - 9 CD47 engagement inhibits cytokine production and maturation of human dendritic cells; Demeure CE et al.; Upon encounter with bacterial products, immature dendritic cells (iDCs) release proinflammatory cytokines and develop into highly stimulatory mature DCs . In the present study, we show that human monocyte-derived DCs functionally express the CD47 Ag, a thrombospondin receptor . Intact or F(ab')2 of CD47 mAb suppress bacteria-induced production of IL-12, TNF-alpha, GM-CSF, and IL-6 by iDCs . 4N1K, a peptide derived from the CD47-binding site of thrombospondin, also inhibits cytokine release . The inhibition of IL-12 and TNF-alpha is IL-10-independent inasmuch as IL-10 production is down-modulated by CD47 mAb and blocking IL-10 mAb fails to restore cytokine levels . CD47 ligation counteracts the phenotypic and functional maturation of iDCs in that it prevents the up-regulation of costimulatory molecules, the loss of endocytic activity, and the acquisition of an increased capacity to stimulate T cell proliferation and IFN-gamma production . Interestingly, regardless of CD47 mAb treatment during DC maturation, mature DC restimulated by soluble CD40 ligand and IFN-gamma, to mimic DC/T interaction, produce less IL-12 and more IL-18 than iDCs . Finally, CD47 ligation on iDCs does not impair their capacity to phagocytose apoptotic cells . We conclude that following exposure to microorganisms, CD47 ligation may limit the intensity and duration of the inflammatory response by preventing inflammatory cytokine production by iDCs and favoring their maintenance in an immature state. Aviakosm Ekolog Med, 1999, 33(6), 48 - 52 {Endogenous regulatory peptides, interferons and cytokines as adaptogens in exposure of the body to adverse environmental factors}; Kalinin IuT et al.; The authors summarize data on the efficacy of various prefabricated recombinant interferons against virus, bacterial, and chlamydial infections, and in unfavorable environments . The spaceflight factors were shown to have a negative influence on natural killers in the human body providing the immunological resistance and defence not only from foreign microorganisms but also the body cells transformed because of a virus infection or malignancy . Entalferon awakes a particular interest for its convenience in extreme conditions, space flight included . It is still an open issue whether the interferon sensitivity of natural killers is compromised by space flight . This trend of investigation seems to be of paramount importance and promise in the context of enhancing the antiviral, antimicrobic and antineoplastic immunity of cosmonauts. Pediatrics, 2000 Feb, 105(2), 311 - 5 Detection of pathogen transmission in neonatal nurseries using DNA markers as surrogate indicators; Oelberg DG et al.; OBJECTIVE: Nosocomial infections are a major problem confronting neonatal intensive care units (NICUs) . This study was conducted to determine if DNA markers designed from the cauliflower mosaic virus (CaMV 35S DNA) can serve as surrogate indicators of nosocomial pathogen transmission in NICUs . METHODS: Regions of cauliflower CaMV 35S promoter DNA were designed to serve as surrogate markers of microbial transmission pathways . Each of 6 pods within the NICU under study houses 8 newborn infants . DNA marker was placed on the telephone handle in only 1 of the 6 NICU pods (study pod) . Bedside caregivers were blinded as to when placebo or marker were placed in the pod . Thirty-two samples were collected from predetermined sites within each pod at 0, 4, 8, 24, and 48 hours and 7 days after DNA placement . Similar sites were sampled in each of the 6 pods . Additional samples were collected concurrently from areas of the NICU segregated from direct patient care . Polymerase chain reactions were performed on collected samples, and products were analyzed by agarose gel electrophoresis . RESULTS: One thousand three hundred samples of the environment and hands of personnel were collected and analyzed . Within the study pod, 58% of sites tested positive for the DNA marker throughout all time points; positive sites peaked at 8 hours (78%) and declined to 23% positive at 7 days . The other 5 pods had a mean of 18% of sites positive throughout the 7 days and exhibited a similar decline throughout time . The most consistently positive sites within all pods were the blood gas analyzers, computer mice, telephone handles, medical charts, ventilator knobs, door handles, radiant warmer control buttons, patient monitors, and personnel hands . In areas outside the pods, the nurse's station, resident physician charting area, changing room, and staff break room had a mean of 50% positive sites throughout all time points . CONCLUSIONS: DNA markers proved useful as safe, surrogate indicators of microorganism transmission within and outside pods in the NICU . We speculate that utilization of these techniques in the hospital environment will provide important information about transmission of pathogens in the NICU, assist in developing and enforcing cleaning procedures, and permit testing of educational intervention programs targeting a decrease in nosocomial infections.nosocomial infection, neonatal intensive care, DNA marker, polymerase chain reaction, infection control. Aliment Pharmacol Ther, 2000 Feb, 14(2), 247 - 56 Characterization of M cell development during indomethacin-induced ileitis in rats; Kucharzik T et al.; BACKGROUND: M cells play an important role in the intestinal immune system as they have a high capacity for transcytosis of a wide range of microorganisms and macromolecules . However, little is known about the role of M cells during intestinal inflammation . AIM: We studied M cell development during indomethacin-induced intestinal inflammation in rats . METHODS: Ileitis in rats was induced by two subcutaneous injections with indomethacin (7.5 mg/kg) given 24 h apart . Rats were sacrificed after 14 days and tissue was analysed by fluorescence microscopy and electron microscopy . M cells could be visualized by using the FITC-labelled mAb anti-cytokeratin (CK)-8 (clone 4.1.18), which was recently identified as specific M cell marker in rats . The number of cytokeratin-8 positive M cells was related to the surface of the follicle associated epithelium . For morphological studies, we used both transmission electron microscopy (T.E.M.) and scanning electron microscopy (S.E.M.) . RESULTS: In non-inflamed ileum M cells were scarce . Only 4% of the follicle associated epithelium were M cells, whereas an increase of M cells up to 11% was found in inflamed follicle associated epithelium (P < 0.001) . The rate of M cell induction depended on the macroscopic degree of inflammation . T.E.M./S.E.M . studies showed that in inflamed tissue most M cells underwent apoptosis with typical morphological signs . In contrast to apoptotic M cells, the neighbouring enterocytes usually appeared intact . The number of mononuclear cells below the follicle associated epithelium was significantly increased . S.E.M . studies revealed that during induced ileitis mononuclear cells migrated from the lamina propria into the gut lumen by passing through apoptotic M cells . CONCLUSIONS: During indomethacin-induced ileitis in rats the increase in M cell number in association with apoptosis of M cells may alter the intestinal barrier function . These observations may play a pivotal role in the pathogenesis of chronic intestinal inflammation, e.g . in inflammatory bowel disease. Phytochemistry, 1999 Dec, 52(7), 1203 - 10 Effectiveness of ascorbate and ascorbate peroxidase in promoting nitrogen fixation in model systems; Ross EJ et al.; Ascorbate and ascorbate peroxidase are important antioxidants that are abundant in N2-fixing legume root nodules . Antioxidants are especially critical in root nodules because leghemoglobin, which is present at high concentrations in nodules, is prone to autoxidation and production of activated oxygen species such as O2.- and H2O2 . The merits of ascorbate and ascorbate peroxidase for maintaining conditions favorable for N2 fixation were examined in two model systems containing oxygen-binding proteins (purified myoglobin or leghemoglobin) and N2-fixing microorganisms (free-living Azorhizobium or bacteroids of Bradyrhizobium japonicum) in sealed vials . The inclusion of ascorbate alone to these systems led to enhanced oxygenation of hemeproteins, as well as to increases in nitrogenase (acetylene reduction) activity . The inclusion of both ascorbate and ascorbate peroxidase resulted in even greater positive responses, including increases of up to 4.5-fold in nitrogenase activity . In contrast, superoxide dismutase did not provide beneficial antioxidant action and catalase alone provided only very marginal benefit . Optimal concentrations were 2 mM for ascorbate and 200 micrograms/ml for ascorbate peroxidase . These concentrations are similar to those found in intact soybean nodules . These results support the conclusion that ascorbate and ascorbate peroxidase are beneficial for maintaining conditions favorable for N2 fixation in nodules. Plant Mol Biol, 1999 Nov, 41(5), 669 - 77 Comparative differential RNA display analysis of arbuscular mycorrhiza in Pisum sativum wild type and a mutant defective in late stage development; Lapopin L et al.; In order to analyse gene expression associated with the late stages of arbuscular mycorrhizal development between Pisum sativum and Glomus mosseae, comparative differential RNA display was carried out using wild-type P . sativum and a mutant, RisNod24, where the fungal partner is not able to form functional arbuscules . Comparison of RNA accumulation patterns between controls, G . mosseae-colonized mutant and wild-type roots resulted in the identification of four differentially occurring cDNA fragments . One of the corresponding genes was from the fungus and three of plant origin . One plant gene, Psam4 (P . sativum arbuscular mycorrhiza-regulated), was analysed in more detail . Sequencing of a cDNA clone showed that Psam4 encodes a proline-rich protein . Northern blot analysis and quantitative RT-PCR revealed a higher basal level of Psam4 RNA accumulation in the mutant compared to the wild type . In both pea genotypes, RNA accumulation was reduced after inoculation with mycorrhiza- or nodule-forming symbiotic microorganisms, but enhanced after infection with a root pathogenic fungus. Bioorg Khim, 1999 Nov, 25(11), 811 - 5 {Endogenous immunoregulatory peptides (myelopeptides): structure, function, and mechanism of action}; Petrov RV et al.; Previously unknown bioregulators from bone marrow, myelopeptides, were isolated, identified, and synthesized, and their biological properties and mechanism of action were studied in detail . Phe-Leu-Gly-Phe-Pro-Thr (MP-1) manifests an immunocorrecting effect by restoring the level of antibody production in animals suffering from immunodeficiencies of various etiologies; Leu-Val-Val-Tyr-Pro-Trp (MP-2) manifests an antitumor effect by abolishing the inhibitory action of tumor cells on the functional activity of T-lymphocytes; Leu-Val-Cys-Tyr-Pro-Gln (MP-3) stimulates phagocytosis by macrophages and, in this way, protects animals from infections caused by pathogenic microorganisms; and Phe-Pro-Arg-Ile-Met-Thr-Pro (MP-4) is a new factor of cell differentiation inducing terminal cell differentiation in the HL-60 and K-562 leukemic cell lines. Vet Pathol, 2000 Jan, 37(1), 82 - 5 Small intestinal adenomatous polyposis resulting in protein-losing enteropathy in a horse; Patterson-Kane JC et al.; A 4-year-old Quarter Horse gelding was presented with a history of weight loss of 6 months duration, along with extensive ventral subcutaneous edema . Clinicopathologic findings included a markedly low serum total protein (2.9 g/dl) and a low packed cell volume (24%) . The mucosal surface of the distal jejunum and entire ileum were carpeted with numerous polypoid, papillary, and glandular masses comprised of pseudostratified tall columnar cells and large numbers of interspersed goblet cells . Neoplastic change was diffuse throughout the mucosa of each mass, but abrupt demarcation occurred between neoplastic masses and adjacent mucosa . Immunohistochemical staining for protein of the p53 tumor suppressor gene revealed only occasional cytoplasmic reactivity within polyps and normal mucosa . Nuclear staining for papillomavirus antigens was not observed . Electron microscopic examination revealed features of well-differentiated intestinal epithelial cells, including apical tight junctions and microvilli, desmosomes, and the presence of numerous goblet cells . Microorganisms were not detected . Small intestinal polyposis should be considered as a rare differential diagnosis for protein-losing enteropathy in the horse. Dev Biol, 1999 Dec 15, 216(2), 426 - 41 Regulation of cell-fate determination in Dictyostelium; Brown JM et al.; A key step in the development of all multicellular organisms is the differentiation of specialized cell types . The eukaryotic microorganism Dictyostelium discoideum provides a unique experimental system for studying cell-type determination and spatial patterning in a developing multicellular organism . Unlike metazoans, which become multicellular by undergoing many rounds of cell division after fertilization of an egg, the social amoeba Dictyostelium achieves multicellularity by the aggregation of approximately 10(5) cells in response to nutrient depletion . Following aggregation, cell-type differentiation and morphogenesis result in a multicellular organism with only a few cell types that exhibit a defined patterning along the anterior-posterior axis of the organism . Analysis of the mechanisms that control these processes is facilitated by the relative simplicity of Dictyostelium development and the availability of molecular, genetic, and cell biological tools . Interestingly, analysis has shown that many molecules that play integral roles in the development of higher eukaryotes, such as PKA, STATs, and GSK-3, are also essential for cell-type differentiation and patterning in Dictyostelium . The role of these and other signaling pathways in the induction, maintenance, and patterning of cell types during Dictyostelium development is discussed. Infect Immun, 2000 Feb, 68(2), 680 - 7 Epitope mapping of immunogenic and adhesive structures in repetitive domains of Mycoplasma bovis variable surface lipoproteins; Sachse K et al.; The family of variable surface lipoproteins (Vsps) of the bovine pathogen Mycoplasma bovis includes some of the most immunogenic antigens of this microorganism . Vsps were shown to undergo high-frequency phase and size variations and to possess extensive reiterated coding sequences extending from the N-terminal end to the C-terminal end of the Vsp molecule . In the present study, mapping experiments were conducted to detect regions with immunogenicity and/or adhesion sites in repetitive domains of four Vsp antigens of M . bovis, VspA, VspB, VspE, and VspF . In enzyme-linked immunosorbent assay experiments, sera obtained from naturally infected cattle showed antibodies to different repeating peptide units of the Vsps, particularly to units R(A)1, R(A)2, R(A)4.1, R(B)2.1, R(E)1, and R(F)1, all of which were found to contain immunodominant epitopes of three to seven amino acids . Competitive adherence trials revealed that a number of oligopeptides derived from various repeating units of VspA, VspB, VspE, and VspF partially inhibited cytoadhesion of M . bovis PG45 to embryonic bovine lung cells . Consequently, putative adherence sites were identified in the same repeating units (R(A)1, R(A)2, R(A)4.1, R(B)2.1, R(E)1, and R(F)1) and in R(F)2 . The positions and lengths of the antigenic determinants were mostly identical to those of adhesion-mediating sites in all short repeating units, whereas in the considerably longer R(F)1 unit (84 amino acid residues), there was only one case of identity among four immunogenic epitopes and six adherence sites . The identification of epitopes and adhesive structures in repetitive domains of Vsp molecules is consistent with the highly immunogenic nature observed for several members of the Vsp family and suggests a possible function for these Vsp molecules as complex adherence-mediating regions in pathogenesis. Gynecol Oncol, 2000 Feb, 76(2), 176 - 82 Expression of complement regulatory proteins-CD 35, CD 46, CD 55, and CD 59-in benign and malignant endometrial tissue; Murray KP et al.; OBJECTIVE: Complement system plays an important role in host defense mechanisms against microorganisms and tumor cells . To protect themselves from autologous complement-mediated damage, normal host tissues express cell membrane-associated complement regulatory proteins (CRPs) . To investigate whether neoplastic endometrial tissues overexpress these proteins to escape complement damage, we examined the distribution of complement receptor type 1 (CR1, CD35), membrane cofactor protein (MCP, CD46), decay-accelerating factor (DAF, CD55), and protectin (MACIF, CD59) on frozen endometrial tissue samples . METHODS: A total of 54 endometrial tissue samples were collected . Cryosections were obtained of 31 benign and 23 malignant tissue specimens . Tissue sections were stained by immunohistochemical staining procedure using specific antibodies and employing the avidin-biotin technique . Quantitation of the protein content of these CRPs was determined using the Samba 4000 image analysis system . RESULTS: For all four of the CRPs studied, a statistically significant difference in protein expression between the benign and malignant endometrial tissue specimens (P < 0.0001) was observed . CONCLUSIONS: Overexpression of all the CRPs studied (CD35, CD46, CD55, CD59) was observed in the malignant as compared with the benign endometrial tissues . The upregulation of these CRPs may promote resistance of the endometrial malignant tissue to complement-mediated damage, thereby allowing the tumor cells to escape from cytolysis and thus promoting carcinogenesis . Rev Clin Esp, 1999 Nov, 199(11), 705 - 10 {Pyogenic liver abscess: changes in etiology, diagnosis and treatment over 18 years}; Corredoira Sanchez JC et al.; BACKGROUND: There are no detailed studies in our country on the impact of modern imaging techniques on diagnosis, treatment and prognosis of pyogenic liver abscesses . MATERIAL AND METHODS: All patients with the diagnosis of PLA from 1981 to 1998 were included in the study . The study was divided in two periods: 1981 to 1989 and 1990 to 1998 . RESULTS: Compared with the first time period, the following was observed from 1990 to 1998: the mean age was higher (52 versus 65 years, p = 0.006), infections with identified source increased (33% versus 74%, p = 0.003), diagnosis was earlier (13 versus 3 days, p = 0.0002), modern imaging techniques were used more frequently (17% versus 96%, p = 0.002), the proportion of recovered microorganisms increased (53% versus 88%, p = 0.002), as well as use of percutaneous drainage (0% versus 37%, p = 0.002) and the prognosis was better (mortality rate 40% versus 10%, p = 0.01) . CONCLUSIONS: Relevant changes were observed among patients in our hospital in the nineties regarding epidemiology, management and prognosis of PLAs . Part of these changes are due to a higher use of new imaging techniques. Berl Munch Tierarztl Wochenschr, 1999 Dec, 112(12), 454 - 8 {Nature and frequency of the existence of mold fungi in garbage cans for biological waste and the resultant airborne spore pollution}; Weinrich M et al.; In organic waste, numerous mold fungi and other microorganisms develop sometimes within a few hours only which decompose the organic material already in the collecting containers generating heat and odor . With regard to the emission of mold fungus spores out of garbage cans for bio-waste and the potential environmental-hygienic danger connected with it, considerable worries have been expressed recently . A wide spectrum of mold fungi can be found in bio-waste in strongly varying concentrations . No noticeable difference could be ascertained between the settlement structure areas and the cities respectively as to the fungus concentration in the bio-waste substrate . A . fumigatus and A . niger can be recommended as leading spores for the behavior of the total concentration of fungi in the bio-waste due to their frequency of detection and their seasonal dynamism . The intensity of the air spore pollution through emission of mold fungus spores correlates closely with the climatic conditions, such as variations of temperature, relative humidity and solar radiation . The airborne release of mold fungus spores out of garbage cans for bio-waste and the formation of a respective exposure connected with it is judged as harmless for healthy persons . Risk patients and persons having a weakened immune system or assumed to have such a one due to an existent basic illness and/or other reasons should avoid any handling of bio-waste as well as any other waste if possible. Circulation, 2000 Jan 18, 101(2), 137 - 41 Association of serology with the endovascular presence of Chlamydia pneumoniae and cytomegalovirus in coronary artery and vein graft disease; Bartels C et al.; BACKGROUND: Chemotherapeutic treatment for patients with symptomatic coronary artery disease to reduce cardiovascular events may be initiated in response to elevated antibody titers against Chlamydia pneumoniae or cytomegalovirus . How antibody titers are associated with the endovascular presence of these microorganisms is still unclear . METHODS AND RESULTS: Antibody titers against C pneumoniae (microimmunofluorescence) and cytomegalovirus (ELISA) in patients undergoing primary (coronary desobliterates, n=80) or repeated CABG (occluded vein grafts, n=45) were correlated with the endovascular presence of the 2 microorganisms . C pneumoniae was detected by means of a nested polymerase chain reaction (PCR) and by culturing . Both conventional PCR and quantitative PCR were applied for detection of cytomegalovirus . C pneumoniae (PCR/culture) was detected in 19/9% (15/80 and 7/80) of coronary desobliterates and in 18/11% (8/45 and 5/45) of occluded vein grafts . There was no statistical evidence that IgG values differed between patients with or without C pneumoniae detection who were undergoing primary CABG . In contrast, repeated-CABG patients with a positive PCR (P=0.0027) or C pneumoniae culture (P=0.0018) had distinctly elevated IgG titers compared with patients in whom C pneumoniae was not detected . Cytomegalovirus could not be detected in the examined specimens . CONCLUSIONS: Cytomegalovirus infection does not seem to be associated with advanced coronary artery lesions . C pneumoniae antibody titers are not associated with the endovascular presence of C pneumoniae in patients with coronary artery disease . The observed strong association between elevated IgG titers and the detection of C pneumoniae in occluded vein grafts warrants further investigation. Chemosphere, 1999 Dec, 39(15), 2723 - 36 A comparative investigation on the biosorption of lead by filamentous fungal biomass; Lo W et al.; The removal of lead from aqueous solutions by adsorption on filamentous fungal biomass was studied . Batch biosorption experiments were performed to screen a series of selected fungal strains for effective lead removal at different metal and biomass concentrations . Biosorption of the Pb2+ ions was strongly affected by pH . The fungal biomass exhibited the highest lead adsorption capacity at pH 6 . Isotherms for the biosorption of lead on fungal biomass were developed and the equilibrium data fitted well to the Langmuir isotherm model . At pH 6, the maximum lead biosorption capacity of Mucor rouxii estimated with the Langmuir model was 769 mg/g dry biomass, significantly higher than that of most microorganisms . Biomass of Mucor rouxii showed specific selectivity for Pb2+ over other metals ions such as Zn2+, Ni2+ and Cu2+ . This fungal strain may be applied to develop potentially cost-effective biosorbent for removing lead from effluents . The technique of scanning electron microscopy coupled with X-ray dispersion analysis shows that Pb2+ has exchanged with K+ and Ca2+ on the cell wall of Mucor rouxii, thereby suggesting ion exchange as one of the dominant mechanisms of metal biosorption for this fungal strain. Aliment Pharmacol Ther, 2000 Jan, 14(1), 15 - 22 Personal review: is profound acid inhibition safe? Waldum HL, Brenna E. Inhibitors of gastric acid secretion, particular proton pump inhibitors, are effective drugs in the treatment and prophylaxis of acid-related diseases . Proton pump inhibitors are therefore prescribed widely, often for minor complaints . Gastric acidity kills swallowed microorganisms, and acid secretion must be of biological importance because it is maintained in phylogenesis . Acid secretion is controlled by feedback mechanisms, mainly via gastrin . A decrease in acidity always causes an increase in plasma gastrin . The trophic effect of gastrin leads to hyperplasia and neoplasia of the enterochromaffin-like (ECL) cell . ECL cell derived tumours in man were previously regarded as rare, and also as rather benign . It is now clear that the ECL cell gives rise to a significant proportion of gastric carcinomas . Moreover, ECL cell carcinoids secondary to hypergastrinaemia may develop into highly malignant tumours . Treatment with a proton pump inhibitor is followed by rebound acid hypersecretion and decreased efficiency of H2-blockers, thus such treatment may induce a type of physical dependence . It is therefore reasonable to be cautious and not to treat younger (< 50 years) patients for long periods of time with profound inhibitors of gastric acid secretion . Chromogranin A in the blood is a sensitive marker of the ECL cell mass, and it could be used to survey patients on long-term proton pump inhibitors. Bioorg Med Chem, 1999 Nov, 7(11), 2329 - 41 Microbial models of drug metabolism: microbial transformations of Trimegestone (RU27987), a 3-keto-delta(4,9(10))-19-norsteroid drug; Lacroix I et al.; Screening microorganisms for the biotransformation of the 3-keto-delta(4,9(10))-19-norsteroid RU27987 (Trimegestone) resulted in the isolation of nine identified metabolites, some of them being selectively produced by different strains . Eight metabolites were found to be hydroxylated on various positions of the rings, and one was additionally epoxidized . These microbial metabolites could be used as chromatographic standards and two of them were found identical to the unknown major human metabolites . Moreover, most microbial metabolites were produced in sufficient amounts to be tested for their biological activities . All these features demonstrate the usefulness and versatility of microbial biotransformation systems as a tool for early identification and convenient production of potentially active mammalian and non-mammalian metabolites. Trends Biotechnol, 2000 Jan, 18(1), 19 - 21 Environmental biotechnology; Wackett LP; There is an increasing interest in environmental biotechnology owing to a worldwide need to feed the world's growing population and to maintain clean soil, air and water . The major technological developments are in plant and microbial biology . Plants can be more readily engineered for resistances that enhance yield or produce new products whereas microorganisms are exploited for their catalytic diversity and ease of genetic engineering. Toxicol Sci, 1999 Dec, 52(2 Suppl), 107 - 10 Conjugated linoleic acid and the control of cancer and obesity; Pariza MW et al.; The effects of conjugated linoleic acid (CLA) in animals are reviewed . In most of the CLA preparations that have been investigated to date for biological activity, two CLA isomers are present in about equal concentrations: cis-9,trans-11 CLA, and trans-10,cis-12 CLA . The occurrence of these isomers in foods and their production by rumen microorganisms are discussed . Potential mechanisms of action as regards the effects of CLA on cancer and body composition are reviewed, including recent evidence that body composition changes are produced by the trans-10,cis-12 CLA isomer . Evidence is presented indicating that CLA may modulate cellular response to tumor necrosis factor-alpha (TNF-alpha) . The mechanistic implications of this finding are considered. J Dairy Sci, 1999 Dec, 82(12), 2651 - 8 Evidence of a role for plant proteases in the degradation of herbage proteins in the rumen of grazing cattle; Zhu WY et al.; Protein breakdown in the rumen is generally regarded as a two-stage process in which proteases produced by rumen microorganisms cleave plant protein into peptides and amino acids . However, many of the fiber-degrading cellulolytic species in the rumen are not in fact proteolytic, and the proteolytic activity of the entire rumen microbial population is only moderate when compared to the gastric and pancreatic secretions in the abomasum . Moreover, plant cell walls remain largely intact after initial chewing (particularly in cattle), presenting a physical barrier that must be breached prior to their effective colonization . The present study considers the hypothesis that the plant enzymes are at least partly responsible for herbage protein degradation in grazing ruminants . Ryegrass, red clover, white clover, and bird's-foot trefoil were incubated in the presence and absence of rumen microorganisms . The production of volatile fatty acids indicated the level of microbial activity, whereas the relative disappearance of the large subunit of ribulose 1,5 bisphosphate carboxylase/oxygenase (Rubisco LSU) indicated proteolytic activity . In all incubations, the relative abundance of the Rubisco LSU decreased as the incubation progressed . When rumen microorganisms were absent, low molecular weight peptides (below 20 kDa) accumulated as the incubation progressed . This accumulation was not observed in the presence of rumen microorganisms . Therefore we suggest that the intrinsic plant proteases contribute to the initial stages of proteolysis of grazed herbage. Antibiot Khimioter, 1999, 44(11), 23 - 30 {The comparative activity of cefepime and other current antibiotics against microorganisms isolated from patients in pediatric intensive therapy units}; Kurchavov VA et al.; Comparative activity of cefepime, ceftazidime, ceftriaxone, ciprofloxacin, imipenem and piperacillin/tazobactam against isolates from patients of pediatric intensive care units within October-December 1998 was studied . The isolates were identified with the Walkaway-40 System . The antibiotic susceptibility was evaluated by the E-test on the Mueller-Hinton II agar . The data were interpreted in accordance with the NCCLS . The number of the isolates totaled 100 . Among them not more than 10 to 12 strains belonged to the same species . 92 per cent of the isolates was susceptible to cefepime and 70 to 75 per cent of the isolates were susceptible to the third generation cephalosporins . Piperacillin/tazobactam proved to be highly susceptible, the number of the isolates resistant and moderately resistant to it being 6 and 1 per cent respectively . The results showed that cefepime was intermediate between the third generation cephalosporins and carbapenems. Circulation, 2000 Dec 12, 102(24), 2919 - 22 Transfer of CD4(+) T cells aggravates atherosclerosis in immunodeficient apolipoprotein E knockout mice; Zhou X et al.; BACKGROUND: Atherosclerosis is associated with immune responses to oxidized lipoproteins and certain microorganisms, but the role of specific immunity has remained unclear . METHODS AND RESULTS: To study the role of immunity in atherosclerosis, we crossed atherosclerosis-prone apoE(-/-) mice with immunodeficient scid/scid mice . The offspring showed a 73% reduction in aortic fatty streak lesions when compared with immunocompetent apoE(-/-) mice . Transfer of CD4(+) T cells from apoE(-/-) to immunodeficient apoE(-/-)/scid/scid mice increased lesions by 164% . This was associated with the infiltration of transferred T cells into lesions, increased circulating interferon-gamma levels, and increased I-A expression in lesions . CONCLUSIONS: CD4(+) T cells carry disease-promoting immunity in atherosclerosis. Stroke, 2000 Dec, 31(12), 2930 - 5 Chlamydia pneumoniae does not influence atherosclerotic plaque behavior in patients with established carotid artery stenosis; Gibbs RG et al.; BACKGROUND AND PURPOSE: Research for infectious agents in the etiology of atherosclerosis has identified Chlamydia pneumoniae as a possible candidate . While there is evidence of an association between presence of this microorganism and atherosclerosis, it is unclear whether infection has a genuinely etiologic role in this disease, whether its presence influences clinical outcomes, and, if so, at which stages of disease this occurs . We have approached this issue in patients with advanced carotid artery atherosclerosis using molecular biological detection methods and clinically relevant indicators of pathology in carotid artery atheroma to determine whether the presence of C pneumoniae correlates with plaque instability . METHODS: C pneumoniae was detected with the use of a sensitive nested polymerase chain reaction . Preoperative embolization and preoperative infarcts were recorded with the use of transcranial Doppler insonation of the middle cerebral artery and cerebral CT, respectively . RESULTS: C pneumoniae DNA was detected in 25.5% of a cohort of 98 symptomatic patients . There was no significant difference in plaque stability as measured by embolization rates between the chlamydial-positive and -negative specimens . There was also no correlation between the number of ipsilateral hemispheric infarcts in the territory of the middle cerebral artery and chlamydial status . CONCLUSIONS: This study confirms that C pneumoniae is a common finding in atherosclerotic plaques of the carotid artery but suggests that the presence of the infectious organism has little detectable impact on plaque instability when measured by clinically significant markers . This raises important questions for the rationale of antibiotic therapy in atherosclerosis. Mol Gen Genet, 1999 Dec, 262(4-5), 772 - 80 Non-LTR retrotransposons with unique integration preferences downstream of Dictyostelium discoideum tRNA genes; Szafranski K et al.; Retrotransposable elements are genetic enti ties which move and replicate within host cell genomes We have previously reported on the structures and ge nomic distributions of two non-long terminal repea (non-LTR) retrotransposons, DRE and Tdd-3, in the eukaryotic microorganism Dictyostelium discoideum DRE elements are found inserted upstream, and Tdd-3 elements downstream, of transfer RNA (tRNA) genes with remarkable position and orientation specificities The data set currently available from the Dictyostelium Genome Project led to the characterisation of two repetitive DNA elements which are related to the D . discoideum non-LTR retrotransposon Tdd-3 in both their structural properties and genomic distributions . It appears from our data that in the D . discoideum genome tRNA genes are major targets for the insertion of mobilised non-LTR retrotransposons . This may be interpreted as the consequence of a process of coevolution, allowing a viable population of retroelements to transpose without being deleterious to the small microbial host genome which carries only short intergenic DNA sequences . A new nomenclature is introduced to designate all tRNA gene-targeted non-LTR retrotransposons (TREs) in the D . discoideum genome . TREs inserted 5' and 3' of tRNA genes are named TRE5 and TRE3, respectively . According to this nomenclature DRE and Tdd-3 are renamed TRE5-A and TRE3-A, respectively . The new retroelements described in this study are named TRE3-B (formerly RED) and TRE3-C. J Biol Chem, 2000 Jan 14, 275(2), 823 - 7 The cytotoxic plant protein, beta-purothionin, forms ion channels in lipid membranes; Hughes P et al.; Thionins are small cysteine-containing, amphipathic plant proteins found in seeds and vegetative tissues of a number of plant genera . Many of them have been shown to be toxic to microorganisms such as fungi, yeast, and bacteria and also to mammalian cells . It has been suggested that thionins are present in seeds to protect them, and the germinating seedling, from attack by phytopathogenic microorganisms, but the mechanism by which they kill cells remains unclear . Using electrophysiological measurements, we have shown that beta-purothionin from wheat flour can form cation-selective ion channels in artificial lipid bilayer membranes and in the plasmalemma of rat hippocampal neurons . We suggest that the generalized toxicity of thionins is due to their ability to generate ion channels in cell membranes, resulting in the dissipation of ion concentration gradients essential for the maintenance of cellular homeostasis. Ann Biomed Eng, 1999 Nov-Dec, 27(6), 697 - 711 Development and application of cell-based biosensors; Pancrazio JJ et al.; Biosensors incorporate a biological sensing element that converts a change in an immediate environment to signals conducive for processing . Biosensors have been implemented for a number of applications ranging from environmental pollutant detection to defense monitoring . Biosensors have two intriguing characteristics: (1) they have a naturally evolved selectivity to biological or biologically active analytes; and (2) biosensors have the capacity to respond to analytes in a physiologically relevant manner . In this paper, molecular biosensors, based on antibodies, enzymes, ion channels, or nucleic acids, are briefly reviewed . Moreover, cell-based biosensors are reviewed and discussed . Cell-based biosensors have been implemented using microorganisms, particularly for environmental monitoring of pollutants . Biosensors incorporating mammalian cells have a distinct advantage of responding in a manner that can offer insight into the physiological effect of an analyte . Several approaches for transduction of cellular signals are discussed: these approaches include measures of cell metabolism, impedance, intracellular potentials, and extracellular potentials . Among these approaches, networks of excitable cells cultured on microelectrode arrays are uniquely poised to provide rapid, functional classification of an analyte and ultimately constitute a potentially effective cell-based biosensor technology . Three challenges that constitute barriers to increased cell-based biosensor applications are presented: analytical methods, reproducibility, and cell sources . Possible future solutions to these challenges are discussed. Biofizika, 1999 Sep-Oct, 44(5), 773 - 95 {Biophysics at the turn of the century: autowaves}; Ivanitskii GR; By the example of the formation of dissipative patterns in Belousov-Zhabotinsky reactions and in population waves of mobile microorganisms, an attempt was made to analyze the development of the "autowave conception" in the last ten years . New results obtained at the Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, were demonstrated . The place of the "autowave conception" among other methods of studying nonlinear cooperative bioprocesses that form the basis of synergism is shown . The review was prepared on the occasion of the 275th anniversary of the Russian Academy of Sciences and the 2nd Biophysical Meeting of Russia. Srp Arh Celok Lek, 1999 Jul-Aug, 127(7-8), 254 - 7 {Sociopathologic behavior and repeated infection with venereal disease}; Bjekic M et al.; INTRODUCTION: The sexually transmitted diseases (STDs) comprise a large group of infections produced by different microorganisms including spirochetes, bacteria, chlamydia, mycoplasme, protozoa, fungi, parasites, and viruses . A considerable number of sexually transmitted diseases patients are STD repeaters . As reported by Marjanovitsh and Laloshevitsh {2}, in Belgrade, among patients who during the years 1985 and 1986 visited the City Department for Skin and Veneral Diseases, because of syphilis or gonorrhea, 22.8% had these diseases two or more times during their lives (male/female ratio 10:1) . In Richert et al . {6} study over 30% of all patients who in one year visited sexually transmitted diseases clinic in Dade County, Florida, returned with a new infection within 3 years of their index visit . The aim of this study was to test the hypothesis that there is a relationship between antisocial behaviour and repeated STD . MATERIAL AND METHODS: Case-control study was performed in the population of Belgrade, from June 1997 to April 1998 . Participants were recruited among patients attending the City Department for Skin and Venereal Diseases of Belgrade because of sexually transmitted diseases (syphilis, gonorrhea, nongonoccocal urethritis and genital warts) . The group comprised 101 patients who in their personal histories already had STD two or more times . The control group consisted of 210 patients treated at the same institution for micotic diseases, patients who in their personal histories have never had STD or had it only once (13% of controls) . All participants were men aged 20 to 50 years and all were from Belgrade . Data on demographic characteristics, sexual history and sexual behaviour, as well as data on use of sedatives, smoking habit and sport activity, and data on antisocial behaviour (alcohol abuse, prostitution, drug abuse, prosecution for minor and criminal offences) were collected from all participants by an anonymous questionnaire . In the present paper only data on antisocial behaviour are presented . In the analysis of data chi 2 was used . RESULTS: According to the results obtained, STD repeaters in comparison to their controls used more frequently alcohol (17.8%:0.9%) and drug 18.8%:3.8%), had more frequently sex for money (17.8%:2.8%), and were more frequently prosecuted for minor offences (58.4%:24.8%) and criminal offences (24.8%:4.3%) . All these differences were statistically significant (p < 0.01) . DISCUSSION: In the present study STD repeaters consumed alcohol more frequently than their controls, especially hard liquors, and 55.5% of them had used alcohol at the time of STD infection . In the study of Myliueva et al . {4}, 50% of venereal disease patients consumed alcohol now and then and 10% consumed alcohol frequently . Scheidt and Windle {5} found that 60% of alcoholics had at least one sexually transmitted disease as the result of a high number of sexual partners, low use of condoms and practicing sex for drugs or money . Alcohol has depressive effect on the central nervous system, reduces anxiety and increases libido . In this study STD repeaters in comparison with their controls were significantly more frequently drug users (the majority of them inhaled drugs) . In several studies conducted in the USA {7, 8} the increase of gonorrhea and syphilis was related to drug use . Upchurch et al . {9} reported that individuals with repeated episodes of gonorrhea were frequently intravenous drug abusers . Drugs are most frequently used by young people, at ages of the highest sexual activity . While most of the subjects developed sexual disinterest and dysfunction with prolonged crack cocaine use, some of them become more sexually promiscuous and consequently contracted sexually transmitted diseases more often . Inciardi /10/ found that 1/3 of men who had exchanged sex for crack (or for money needed to by crack) had 100 or more sex partners during a 30-day period prior to study recruitment . Cleghorn et al . (ABSTRACT TRUNCAT Am J Vet Res, 1999 Dec, 60(12), 1531 - 5 Influence of age and parity on the distribution of cells expressing major histocompatibility complex class II, CD4, or CD8 molecules in the endometrium of mares during estrus; Tunon AM et al.; OBJECTIVE: To evaluate effect of age and parity on distribution and number of cells expressing major histocompatibility complex (MHC) class II, CD4, or CD8 molecules in the endometrium of mares during estrus . ANIMALS: 32 gynecologically healthy mares, categorized as young (3 to 8 years; n = 17) or old (9 to 16 years; 15) and nulliparous (n = 6), nulliparous embryo donors (16), or parous (10) . PROCEDURES: Endometrial specimens collected from the uterine body and horns during estrus were stained by use of the avidin-biotin-peroxidase method, using monoclonal antibodies against equine MHC class II, CD4, and CD8 molecules . Labeled cells in the stratum compactum within 5 randomly selected fields at 400x magnification (total area = 0.31 mm2) were counted, and numbers were compared among groups and between locations . RESULTS: Age did not affect cell numbers within the 3 cell subsets examined . Numbers in each subset were higher in the uterine body than in the horns, although the difference was not significant for cells expressing MHC class II . Significantly more cells expressing MHC class II molecules were detected in the uterine body of nulliparous and parous mares than in embryo donors, whereas in the horns, these cells were significantly higher in number only in parous mares . Parity did not affect number of CD4+ or CD8+ cells . CONCLUSIONS AND CLINICAL RELEVANCE: The increased likelihood for endometritis to develop in mares as they age cannot be explained by a decrease in number of cells expressing MHC class II, CD4, or CD8 molecules within the endometrium . However, greater number of cells within these 3 subsets detected in the uterine body, compared with the horns, during estrus suggests a local readiness to act against microorganisms or semen introduced during mating or insemination. Am J Vet Res, 1999 Dec, 60(12), 1474 - 7 Isolation and characterization of the eighth component of the bovine complement system; Menger M et al.; OBJECTIVE: To isolate and characterize the eighth component of the complement system (C8) in cattle . SAMPLE POPULATION: Fresh plasma obtained from beef cattle . PROCEDURES: Plasma samples were fractionated, using sequential precipitation and ion-exchange and gel-filtration chromatography, to yield C8 . The protein was identified throughout the procedure on the basis of its hemolytic function . Electrophoresis in polyacrylamide gels was used to determine molecular weight and composition of polypeptide chains . Reconstitution of classical and alternative complement pathways was used to characterize the hemolytic function of bovine C8 . RESULTS: The bovine C8 protein consisted of a disulfide-bonded alpha-gamma heterodimer that was noncovalently associated with a beta chain . Apparent molecular weight of the alpha, beta, and gamma chains under reducing conditions were 66, 61, and 23 kd, respectively . In the classical pathway of activation, bovine C8 and the ninth component of the complement system (C9) had species incompatibility with human C8 and C9 on sheep erythrocyte target cells . CONCLUSIONS: A simple 4-step fractionation procedure provided good yield of bovine C8 from plasma . The isolated protein was structurally comparable to C8 from other species . Purified bovine C8 may be useful in functional hemolytic assays to investigate the roles of complement-mediated lysis in the pathogenesis of inflammatory diseases and the killing of susceptible microorganisms. Mol Ecol, 1999 Nov, 8(11), 1935 - 45 Acetone preservation: a practical technique for molecular analysis; Fukatsu T; In attempts to establish a convenient and reliable method for field collection and archival preservation of insects and their endosymbiotic microorganisms for molecular analysis, acetone, ethanol, and other organic solvents were tested for DNA preservability of the pea aphid Acyrthosiphon pisum and its intracellular symbiotic bacterium Buchnera sp . After 6 months' storage, not only the band of high-molecular-size DNA but also the bands of rRNA were well preserved in acetone, ethanol, 2-propanol, diethyl ether and ethyl acetate . Polymerase chain reaction (PCR) assays confirmed that the DNA of both the insects and their symbionts was well preserved in these solvents . In contrast, methanol and chloroform showed poor DNA preservability . When water-containing series of acetone and ethanol were examined for DNA preservability, acetone was apparently more robust against water contamination than ethanol . Considering that most biological materials contain high amounts of water, acetone may be a more recommendable preservative for DNA analysis than ethanol which has been widely used for this purpose . The DNA of various insects could be preserved in acetone at room temperature in good condition for several years . In addition to the DNA of the host insects, the DNA of their endosymbionts, including Buchnera and other mycetocyte symbionts, Wolbachia, and gut bacteria, was amplified by PCR after several years of acetone storage . The RNA and protein of the pea aphid and its endosymbiont were also preserved for several years in acetone . After 2 years' storage in acetone, proteins of A . pisum could be analysed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting, and the endosymbiotic bacteria were successfully detected by immunohistochemistry and in situ hybridization on the tissue sections. J Steroid Biochem Mol Biol, 1999 Nov, 71(1-2), 83 - 90 Biotransformation XLVII: transformations of 5-ene steroids in Fusarium culmorum culture; Kolek T; The course of the transformation of six 5-ene steroids with varying substituents at C-17 or/and C-3: dehydroepiandrosterone (DHEA), 5-androsten-3beta,17beta-diol, 17alpha-methyl-5-androsten-3beta,17beta-diol, 5-androsten-17-one, 5-androsten-3beta-ol and pregnenolone by Fusarium culmorum was investigated . Three substrates with oxygen functions at C-3 and C-17 i.e . DHEA, 5-androsten-3beta,17beta-diol and 17alpha-methyl-5-androsten-3beta,17beta-diol were hydroxylated entirely at 7alpha-axial, allylic position . The mixture of 7alpha-hydroxy- and 7alpha,15alpha-dihydroxyderivatives was formed during the transformation of pregnenolone and 5-androsten-17-one, from the latter 2alpha,7alpha-dihydroxyderivative was also obtained . 7alpha,15alpha- Dihydroxyderivative was the only product isolated from the 5-androsten-3beta-ol post-transformation mixture . The time-course of the DHEA transformation by F . culmorum shows that the substrate induces 7alpha-hydroxylase activity . DHEA was transformed by androstenedione induced F . culmorum cultures to a larger extent than by a noninduced microorganism; the selectivity of the transformation remained unchanged. Mod Pathol, 1999 Dec, 12(12), 1152 - 7 Alendronate-associated esophageal injury: pathologic and endoscopic features; Abraham SC et al.; Ingestion of alendronate sodium (Fosamax) by osteoporotic patients can be associated with esophagitis and esophageal ulcer . Alendronate can damage the esophagus both by toxicity from the medication itself and by nonspecific irritation secondary to contact between the pill and the esophageal mucosa, similar to other cases of "pill esophagitis." Despite its wide use, the histologic appearances of alendronate-associated esophageal ulceration have not been previously described in detail, nor is this type of medication-induced injury commonly appreciated by pathologists when evaluating biopsies from ulcer sites . We report a series of 10 patients who experienced erosive/ulcerative esophagitis while ingesting alendronate, and describe the associated endoscopic and pathologic features . Biopsies from all patients showed inflammatory exudate and inflamed granulation tissue as characteristic of any ulcer site . Polarizable crystalline foreign material was present in six of 10 biopsies (60%) . Multinucleated giant cells within the inflammatory exudate were present near this crystalline foreign material in three of 10 biopsies (30%) . Adjacent squamous epithelium typically showed active inflammation and a reactive appearance with enlarged, hyperchromatic nuclei . Multinucleated squamous epithelial giant cells were present in two of 10 cases (20%) . Microorganisms were unusual; scattered fungi and/or viral inclusions were present in only two of 10 biopsies (20%) . Recognition of alendronate-as