J Biol Chem, 2001 Aug 3, 276(31), 29292 - 8 Epub 2001 May 11. Pentaketide melanin biosynthesis in Aspergillus fumigatus requires chain-length shortening of a heptaketide precursor; Tsai HF et al.; Chain lengths and cyclization patterns of microbial polyketides are generally determined by polyketide synthases alone . Fungal polyketide melanins are often derived from a pentaketide 1,8-dihydroxynaphthalene, and pentaketide synthases are used for synthesis of the upstream pentaketide precursor, 1,3,6,8-tetrahydroxynaphthalene (1,3,6,8-THN) . However, Aspergillus fumigatus, a human fungal pathogen, uses a heptaketide synthase (Alb1p) to synthesize its conidial pigment through a pentaketide pathway similar to that which produces 1,8-dihydroxynaphthalene-melanin . In this study we demonstrate that a novel protein, Ayg1p, is involved in the formation of 1,3,6,8-THN by chain-length shortening of a heptaketide precursor in A . fumigatus . Deletion of the ayg1 gene prevented the accumulation of 1,3,6,8-THN suggesting the involvement of ayg1 in 1,3,6,8-THN production . Genetic analyses of double-gene deletants suggested that Ayg1p catalyzes a novel biosynthetic step downstream of Alb1p and upstream of Arp2p (1,3,6,8-THN reductase) . Further genetic and biochemical analyses of the reconstituted strains carrying alb1, ayg1, or alb1 + ayg1 indicated that Ayg1p is essential for synthesis of 1,3,6,8-THN in addition to Alb1p . Cell-free enzyme assays, using the crude Ayg1p protein extract, revealed that Ayg1p enzymatically shortened the heptaketide product of Alb1p to 1,3,6,8-THN . Thus, the protein Ayg1p facilitates the participation of a heptaketide synthase in a pentaketide pathway via a novel polyketide-shortening mechanism in A . fumigatus. J Clin Periodontol, 2001 Jun, 28(6), 524 - 35 Prevalence and risk indicators for destructive periodontal diseases in 3 urban American minority populations; Craig RG et al.; BACKGROUND, AIMS: Destructive periodontal diseases have been reported disproportionately more prevalent and severe in African-Americans relative to other American populations . Differences in subgingival microbiota and host immune response have also been reported for African-Americans, implying that risk factors for disease progression may also differ for these populations . Since it is not clear whether these differences are truly genetic or due to confounding variables such as social economic status, we examined a series of clinical, environmental, demographic, and microbiologic features associated with periodontal disease status in a group of 185 urban minority subjects resident within the greater New York metropolitan area . METHODS: The study population consisted of 56 Asian-American, 71 African-American and 58 Hispanic subjects . Clinical data recorded included pocket depth, attachment level, gingival erythema, bleeding upon probing, suppuration, and the presence of supragingival plaque . Environmental and demographic data recorded included smoking history, years resident in the United States, whether the subject reported a private dentist and occupational status . Subgingival plaque was sampled from the mesial aspect of all teeth exclusive of third molars and the levels of 40 subgingival species enumerated using checkerboard DNA-DNA hybridization . RESULTS: The African-American group had more missing teeth, deeper periodontal pocket depth and more attachment loss than the Asian-American or Hispanic groups . However, the African-American group were less likely to report having a private dentist, had a greater proportion of smokers and a greater proportion of unskilled individuals . The profile of subgingival species differed among the three ethnic/racial groups with A . actinomycetemcomitans, N . mucosa, S . noxia and T . socranskii significantly elevated in the Asian-American group and P . micros significantly elevated in the African-American group . When subset by occupational status, numbers of missing teeth, pocket depth, attachment level and prior disease activity were all found increased in the unskilled relative to the professional group . Local factors including the mean % of sites with plaque, marginal gingival erythema, bleeding upon probing and suppuration were also elevated in the unskilled group . The microbial profile differed among the 3 occupational groups with the unskilled group having elevated numbers of species associated with destructive periodontal diseases . CONCLUSIONS: Although greater destructive periodontal disease prevalence and severity were found in the African-American group, these results suggest that environmental and demographic variables, such as occupational status, may have a greater influence on risk indicators associated with disease prevalence and progression in these populations. J Clin Periodontol, 2001 May, 28(5), 483 - 8 Interleukin-4 polymorphisms in early onset periodontitis; Michel J et al.; BACKGROUND, AIMS: Periodontitis is the result of a complex interplay between oral bacteria and the host response, often modulated by behavioral factors . Early-onset periodontitis (EOP) is defined by the age of onset, the distribution of lesions and specific microbial pathogens . METHOD: Studies in twins suggested a genetic contribution to the pathogenesis of periodontitis . EOP heritable factors may be related to immune mechanisms which could enhance the pathogenic potential of plaque bacteria in susceptible individuals . Among others, Interleukin 4 (IL-4) is a potent cytokine in the immune response and is a potent down regulator of macrophage function . In the present study, we report a specific genotype of the IL-4 gene, which was detected by specific primers and PCR analysis . RESULTS: In the EOP-group 27.8% were IL-4 promotor- and intron polymorphism positive (PP+ and IP+) . None of the age-matched healthy controls or patients with adult periodontitis (n=25) carried the markers . Moreover, serum IL-4 levels of PP+ and IP+ patients were below the detection limit and significantly different (p<0.01) from the IL-4 concentrations of healthy controls and PP- and IP- patients. J Clin Periodontol, 2001 May, 28(5), 389 - 96 Interleukin-1 gene polymorphism and periodontal status . A case-control study; Papapanou PN et al.; OBJECTIVES: This case-control study examined polymorphisms at the interleukin-1 gene in relation to periodontal status, subgingival bacteria and systemic antibodies to periodontal microbiota . METHODS: 132 periodontitis patients were age- and gender-matched with 73 periodontally intact controls . Full-mouth clinical assessments of the periodontal tissues were performed . Subgingival plaque samples (2440 in total) were analyzed by genomic DNA probes, and serum IgG antibodies to periodontal microbiota were assessed by an immunoassay . Polymorphisms in the IL-1A gene at position +4845 and the IL-1B gene at position +3953 were studied by PCR . A composite positive genotype was defined as at least one rare (#2) allele present at each locus . RESULTS: No skewed distribution of the composite genotype was observed between cases and controls (45.2% vs 41.7%) . In cases, both the composite genotype and the number of #2 alleles were positively correlated with the severity of attachment loss . No relationship between genotype and subgingival microbial profiles was observed . Genotype positive patients revealed both overall lower serum antibody levels and specific titers against selected bacteria . CONCLUSIONS: The composite genotype failed to distinguish between periodontitis patients and controls but correlated in patients with the severity of the disease and the antibody responses to periodontal microbiota. J Clin Periodontol, 2001 May, 28(5), 377 - 88 Relationship of cigarette smoking to the subgingival microbiota; Haffajee AD et al.; BACKGROUND: The relationship of cigarette smoking to the composition of the subgingival microbiota is not clear . Some studies indicated higher levels of certain species in smokers, while other studies failed to detect differences in the microbiota between subjects with different smoking histories . Thus, the purpose of the present investigation was to examine the prevalence, proportions and levels of the subgingival species in adult subjects who were current, past or never smokers . METHOD: 272 adult subjects ranging in age from 20-86 years with at least 20 teeth were recruited for study . Smoking history was obtained using a questionnaire . Clinical measures were taken at 6 sites per tooth at all teeth excluding third molars at a baseline visit . Subgingival plaque samples were taken from the mesial surface of all teeth excluding third molars in each subject at baseline and assayed individually for counts of 29 subgingival species using checkerboard DNA-DNA hybridization . Subjects were subset according to smoking history into never (n=124), past (n=98) and current smokers (n=50) . Uni-variate and multi-variate analyses were used to seek associations between smoking category and the counts, proportions and prevalence of subgingival species . RESULTS: Greater differences were observed for the prevalence (% of sites colonized) of the test species in the 3 smoking groups than were observed for counts or proportions of total counts . Members of the orange and red complexes including E . nodatum, F . nucleatum ss vincentii, P . intermedia, P . micros, P . nigrescens, B . forsythus, P . gingivalis and T . denticola were significantly more prevalent in current smokers than in the other 2 groups . The difference in prevalence between smokers and non-smokers was due to greater colonization at sites with pocket depth <4 mm . Stepwise multiple linear regression analysis indicated that combinations of the prevalence of 5 microbial species and pack years accounted for 44% of the variance for mean pocket depth (p<0.000001), while the prevalence of 3 microbial taxa along with age, pack years, current smoking and gender accounted for 31% of the variance in mean attachment level (p<0.000001) . The difference in prevalence between current and never smokers of all members of the red complex and 8 of 12 members of the orange complex was significantly greater in the maxilla than in the mandible . CONCLUSIONS: The major difference between the subgingival microbiota in subjects with different smoking history was in the prevalence of species rather than counts or proportions . The greater extent of colonization in smokers appeared to be due to greater colonization at pocket depths <4 mm . Differences in colonization patterns between current and never smokers were greater in the maxilla than in the mandible. Regul Toxicol Pharmacol, 2001 Apr, 33(2), 173 - 86 Evaluating the safety of microbial enzyme preparations used in food processing: update for a new century; Pariza MW et al.; Microbial enzymes used in food processing are typically sold as enzyme preparations that contain not only a desired enzyme activity but also other metabolites of the production strain, as well as added materials such as preservatives and stabilizers . The added materials must be food grade and meet applicable regulatory standards . The purpose of this report is to present guidelines that can be used to evaluate the safety of the metabolites of the production strain that are also present in the enzyme preparation, including of course, but not limited to, the desired enzyme activity itself . This discussion builds on previously published decision tree mechanisms and includes consideration of new genetic modification technologies, for example, modifying the primary structure of enzymes to enhance specific properties that are commercially useful . The safety of the production strain remains the primary consideration in evaluating enzyme safety, in particular, the toxigenic potential of the production strain . Thoroughly characterized nonpathogenic, nontoxigenic microbial strains, particularly those with a history of safe use in food enzyme manufacture, are logical candidates for generating a safe strain lineage, through which improved strains may be derived via genetic modification by using either traditional/classical or rDNA strain improvement strategies . The elements needed to establish a safe strain lineage include thoroughly characterizing the host organism, determining the safety of all new DNA that has been introduced into the host organism, and ensuring that the procedure(s) that have been used to modify the host organism are appropriate for food use . Enzyme function may be changed by intentionally altering the amino acid sequence (e.g., protein engineering) . It may be asked if such modifications might also affect the safety of an otherwise safe enzyme . We consider this question in light of what is known about the natural variation in enzyme structure and function and conclude that it is unlikely that changes which improve upon desired enzyme function will result in the creation of a toxic protein . It is prudent to assess such very small theoretical risks by conducting limited toxicological tests on engineered enzymes . The centerpiece of this report is a decision tree mechanism that updates previous enzyme safety evaluation mechanisms to accommodate advances in enzymology . We have concluded that separate mutagenicity testing is not needed if this decision tree is used to evaluate enzyme safety . Under the criteria of the decision tree, no new food enzyme can enter the market without critical evaluation of its safety . Environ Sci Technol, 2001 Feb 15, 35(4), 703 - 12 Biotransformation of Ni-substituted hydrous ferric oxide by an Fe(III)-reducing bacterium; Fredrickson JK et al.; The reductive biotransformation of a Ni(2+)-substituted (5 mol %) hydrous ferric oxide (NiHFO) by Shewanella putrefaciens, strain CN32, was investigated under anoxic conditions at circumneutral pH . Our objectives were to define the influence of Ni2+ substitution on the bioreducibility of the HFO and the biomineralization products formed and to identify biogeochemical factors controlling the phase distribution of Ni2+ during bioreduction . Incubations with CN32 and NiHFO were sampled after 14 and 32 d, and both aqueous chemistry and solid phases were characterized . By comparison of these results with a previous study (Fredrickson, J . K.; Zachara, J . M.; Kennedy, D . W.; Dong, H.; Onstott, T . C.; Hinman, N . W.; Li, S . W . Geochim . Cosmochim . Acta 1998, 62, 3239-3257), it was concluded that coprecipitated/sorbed Ni2+ inhibited the bioreduction of HFO through an undefined chemical mechanism . Mossbauer spectroscopy allowed analysis of the residual HFO phase and the identity and approximate mass percent of biogenic mineral phases . The presence of AQDS, a soluble electron shuttle that obviates need for cell--oxide contact, was found to counteract the inhibiting effect of Ni2+ . Nickel was generally mobilized during bioreduction in a trend that correlated with final pH, except in cases where PO4(3-) was present and vivianite precipitation occurred . CN32 promoted the formation of Ni(2+)-substituted magnetite (Fe2IIIFe(1-x)IINixIIO4) in media with AQDS but without PO4(3-) . The formation of this biogenic coprecipitate, however, had little discernible impact on final aqueous Ni2+ concentrations . These results demonstrate that coprecipitated Ni can inhibit dissimilatory microbial reduction of amorphous iron oxide, but the presence of humic acids may facilitate the immobilization of Ni within the crystal structure of biogenic magnetite. Infect Immun, 2001 Jun, 69(6), 3611 - 7 Timing, localization, and persistence of colonization by segmented filamentous bacteria in the neonatal mouse gut depend on immune status of mothers and pups; Jiang HQ et al.; As a member of the indigenous gut mucosal microbiota, segmented filamentous bacteria (SFB) colonize the guts of a variety of vertebrates and invertebrates . They are potent microbial stimuli of the gut mucosal immune system . In the small intestines of mice and rats, it has been observed that SFB are absent during the suckling period and appear in high numbers shortly after weaning, then quickly retreat to the cecum and large intestine . In this study, we explored whether this microecological phenomenon resulted from the interaction between SFB and the passively acquired maternal mucosal immunity and/or the actively acquired mucosal immunity . We set up a mouse model by reciprocal crossings and backcrossings of SFB-monoassociated, formerly germ-free, immunocompetent (+/+) BALB/c mice and immunodeficient (scid/scid) mice to produce pups which are either immunocompetent (scid/+) or immunodeficient (scid/scid) and are born either to immunocompetent (scid/+) mothers or to immunodeficient (scid/scid) mothers . We monitored the number of SFB on the mucosa of the small intestine in the four different groups of mice after birth, as well as the level of passively acquired antibodies, the active gut mucosal immune responses, and immunoglobulin A (IgA) coating of SFB in the gut . The results showed that, irrespective of whether the pups were scid/scid or scid/+, SFB could be found earlier on the mucosa of the small intestine in pups born to scid/scid mothers, appearing from day 13 and rapidly reaching a climax around weaning time on day 28, compared to the significantly delayed colonization in the pups of scid/+ mothers, starting from day 16 and peaking around days 28 to 32 . After the climax, SFB quickly declined to very low levels in the small intestines of scid/+ pups of either scid/scid mothers or scid/+ mothers, whereas they remained at high levels in scid/scid pups at least until day 70, the last observation time in this study . The dynamic changes in SFB colonization of the small intestines of the different groups of pups may be related to the dynamic changes in the levels of SFB coated with secretory IgA (sIgA), which resulted from the significantly different levels of sIgA obtained from the mothers' milk during the suckling period and, later, of self-produced sIgA in the small intestine . Nevertheless, it is evident that the timing, localization, and persistence of colonization of the neonatal gut by SFB depends on the immune status of both mothers and pups. Mol Ecol, 2001 Apr, 10(4), 947 - 64 A microbial population-species interface: nested cladistic and coalescent inference with multilocus data; Carbone I et al.; Using sequence data from seven nuclear loci in 385 isolates of the haploid, plant parasitic, ascomycete fungus, Sclerotinia, divergence times of populations and of species were distinguished . The evolutionary history of haplotypes on both population and species scales was reconstructed using a combination of parsimony, maximum likelihood and coalescent methods, implemented in a specific order . Analysis of site compatibility revealed recombination blocks from which alternative (marginal) networks were inferred, reducing uncertainty in the network due to recombination . Our own modifications of Templeton and co-workers' cladistic inference method and a coalescent approach detected the same phylogeographic processes . Assuming neutrality and a molecular clock, the boundary between divergent populations and species is an interval of time between coalescence (to a common ancestor) of populations and coalescence of species. J Appl Microbiol, 2001 May, 90(5), 713 - 8 Crenarchaeota and Euryarchaeota in temperate estuarine sediments; Abreu C et al.; AIMS: Application of molecular techniques to ecological studies has unveiled a wide diversity of micro-organisms in natural communities, previously unknown to microbial ecologists . New lineages of Archaea were retrieved from several non-extreme environments, showing that these micro-organisms are present in a large variety of ecosystems . The aim was therefore to assess the presence and diversity of Archaea in the sediments of the river Douro estuary (Portugal), relating the results obtained to ecological data . METHODS AND RESULTS: Total DNA was extracted from sediment samples obtained from an estuary deprived of vegetation, amplified by PCR and the resulting DNA fragments cloned . The archaeal origin of the cloned inserts was checked by Southern blot, dot blot or colony blot hybridization . Recombinant plasmids were further analysed by restriction with AvaII and selected for sequencing . Phylogenetic analyses of 14 sequences revealed the presence of members of the domain Archaea . Most of the sequences could be assigned to the kingdom Crenarchaeota . CONCLUSION: Most of these sequences were closely related to those obtained from non-extreme Crenarchaeota members previously retrieved from diverse ecosystems, such as freshwater and marine environments . SIGNIFICANCE AND IMPACT OF THE STUDY: The presence of archaeal 16S rDNA sequences in temperate estuarine sediments emerges as a valuable contribution to the understanding of the complexity of the ecosystem. Environ Sci Technol, 2001 Apr 1, 35(7), 1385 - 93 Microbial reduction of Fe(III) and sorption/precipitation of Fe(II) on Shewanella putrefaciens strain CN32; Liu C et al.; The influence of Fe(II) on the dissimilatory bacterial reduction of an Fe(III) aqueous complex (Fe(III)-citrate(aq)) was investigated using Shewanella putrefaciens strain CN32 . The sorption of Fe(II) on CN32 followed a Langmuir isotherm . Least-squares fitting gave a maximum sorption capacity of Qmax = 4.19 x 10(-3) mol/10(12) cells (1.19 mmol/m2 of cell surface area) and an affinity coefficient of log K = 3.29 . The growth yield of CN32 with respect to Fe(III)aq reduction showed a linear trend with an average value of 5.24 (+/-0.12) x 10(9) cells/mmol of Fe(III) . The reduction of Fe(III)aq by CN32 was described by Monod kinetics with respect to the electron acceptor concentration, Fe(III)aq, with a half-saturation constant (Ks) of 29 (+/-3) mM and maximum growth rate (micromax) of 0.32 (+/-0.02) h(-1) . However, the pretreatment of CN32 with Fe(II)aq significantly inhibited the reduction of Fe(III)aq, resulting in a lag phase of about 3-30 h depending on initial cell concentrations . Lower initial cell concentration led to longer lag phase duration, and higher cell concentration led to a shorter one . Transmission electron microscopy and energy dispersive spectroscopy revealed that many cells carried surface precipitates of Fe mineral phases (valence unspecified) during the lag phase . These precipitates disappeared after the cells recovered from the lag phase . The cell inhibition and recovery mechanisms from Fe(II)-induced mineral precipitation were not identified by this study, but several alternatives were discussed . A modified Monod model incorporating a lag phase, Fe(II) adsorption, and aqueous complexation reactions was able to describe the experimental results of microbial Fe(III)aq reduction and cell growth when cells were pretreated with Fe(II)aq. J Food Prot, 2001 May, 64(5), 674 - 81 Estimating the frequency of high microbial counts in commercial food products using various distribution functions; Corradini MG et al.; Industrial microbial count records usually form an irregular fluctuating time series . If the series is truly random or weakly autocorrelated, the fluctuations can be considered as the outcome of the interplay of numerous factors that promote or inhibit growth . These factors usually balance each other, although not perfectly, hence, the random fluctuations . If conditions are unchanged, then at least in principle the probability that they will produce a coherent effect, i.e., an unusually high (or low) count of a given magnitude, can be calculated from the count distribution . This theory was tested with miscellaneous industrial records (e.g., standard plate count, coliforms, yeasts) of various food products, including a dairy-based snack, frozen foods, and raw milk, using the normal, log normal, Laplace, log Laplace, Weibull, extreme value, beta, and log beta distribution functions . Comparing predicted frequencies of counts exceeding selected levels with those actually observed in fresh data assessed their efficacy . No single distribution was found to be inherently or consistently superior . It is, therefore, suggested that, when the probability of an excessive count is estimated, several distribution functions be used simultaneously and a conservative value be used as the measure of the risk. Environ Sci Technol, 2001 Jan 15, 35(2), 247 - 54 Spatial variations and chronologies of aliphatic hydrocarbons in Lake Michigan sediments; Doskey PV; Four sediment cores were collected in fine-grained depositional areas of the southern basin of Lake Michigan . Spatial variations of aliphatic hydrocarbons in surficial sediments were consistent with a lakeward movement of riverine sediments in a series of resuspension-settling cycles in which an unresolved complex mixture (UCM) of hydrocarbons associated with dense sediments is deposited in nearshore areas, fine-grained sediments of terrestrial origin accumulate in the deep basin, and planktonic hydrocarbons are depleted by microbial degradation during transport to the deep basin . The rate of accumulation of the UCM (a marker of petroleum residues) in deep basin sediments has increased by more than an order of magnitude since 1880, from 60 microg m(-2) x a(-1) to approximately 960 microg m(-2) x a(-1) in 1980 . Crude estimates of the atmospheric loading of the UCM (1100 microg m(-2) x a(-1)) indicate that accumulations in deep-basin sediments might be supported by atmospheric deposition . Agreement was poor between the atmospheric flux of the terrestrial n-alkanes (sigmaC25, C27, C29, C31) to the deep basin (3200 microg m(-2) x a(-1)) and the sediment accumulation rate (660 microg m(-2) x a(-1)) . Understanding of atmospheric fluxes, estimated from the very few available data, would be improved by more frequent measurement of the levels of aliphatic hydrocarbons in air and precipitation and a better knowledge of the particle deposition velocities and precipitation scavenging coefficients. Isr Med Assoc J, 2000 Dec, 2(12), 919 - 23 Emerging infectious diseases: a cause for concern; Berns DS et al.; As the twenty-first century begins it becomes increasingly apparent that the twentieth century, which opened with the promise of the eradication of most infectious diseases, closed with the specter of the reemergence of many deadly infectious diseases that have a rapidly increasing incidence and geographic range . Equally if not more alarming is the appearance of new infectious diseases that have become major sources of morbidity and mortality . Among recent examples are HIV/AIDS, hantavirus pulmonary syndrome, Lyme disease, hemolytic uremic syndrome (caused by a strain of Escherichia coli), Rift Valley fever, Dengue hemorrhagic fever, malaria, cryptosporidiosis, and schistosomiasis . The reasons for this situation are easily identified in some cases as associated with treatment modalities (permissive use of antibiotics), the industrial use of antibiotics, demographic changes, societal behavior patterns, changes in ecology, global warming, the inability to deliver minimal health care and the neglect of well-established public health priorities . In addition is the emergence of diseases of another type . We have begun to characterize the potential microbial etiology of what has historically been referred to as chronic diseases. J, Exp . Mar . Biol . Ecol. . 2001 May 15, 259(2), 171 - 187 Acinar primary cell culture from the digestive gland of Pecten maximus (L.): an original model for ecotoxicological purposes; Le Pennec G et al.; The purpose of this study was to establish an original primary acinar cell culture model for the mollusc bivalve Pecten maximus (L.), and to define its values and limits for subsequent ecotoxicological applications . To prevent microbial contaminations occurring frequently in invertebrate cell cultures, a perfusion of the stomach-digestive gland complex was performed in situ using a sterile salt solution containing broad-range antibiotics . Digestive acini were isolated using a pronase enzyme that was removed by several washings of the acinar suspension, after which their viability and functionality were determined by three different assays: fluorescein diacetate (FDA) de-esterification, 3-4,5-dimethylthiazol-2-yl-2,5-diphenyl tetrazolium (MTT) reduction and neutral red (NR) incorporation describing de-esterification, mitochondrial dehydrogenase and lysosome activity, respectively . The kinetic conditions for these assays were defined beforehand . The results showed that digestive acini could be maintained in vitro both cytologically and functionally for at least 96 h, which is sufficient for many ecotoxicological applications . Preliminary contamination assays, according to the function studied (cell esterases, mitochondrial respiration, lysosomal incorporation), indicated that polycyclic aromatic hydrocarbons had a negative effect on the survival of acini in vitro. J Infect Dis, 2001 Jun 1, 183(11), 1592 - 600 Epub 2001 May 01. A human immunodeficiency virus-transgenic mouse model for assessing interventions that block microbial-induced proviral expression; Schito ML et al.; A human immunodeficiency virus (HIV) type 1-transgenic mouse line (166) that previously showed up-regulated expression of viral proteins and infectious particles after infection with pathogenic agents was tested as a model for screening the in vitro and in vivo efficacy of inhibitors of HIV-1 immune activation . Two types of interventions were assessed: use of either the immunosuppressive drug prednisolone or an HIV-1 envelope-targeted toxin (sCD4-PE40) . Both agents inhibited lipopolysaccharide-induced p24 expression by splenocytes in vitro and, when administered to transgenic mice, suppressed the induction of plasma p24, as well as the ex vivo production of p24 and infectious virus stimulated by in vivo infection with Mycobacterium avium . Moreover, HIV-1 mRNA levels in the spleen were greatly reduced in mice treated with either agent . Because HIV-1 expression cannot be induced in T lymphocytes from line 166 mice, this model may be of particular advantage for testing interventions that target virus production by non-T cell virus reservoirs. J Immunol, 2001 May 15, 166(10), 6332 - 40 Antioxidants inhibit indoleamine 2,3-dioxygenase in IFN-gamma-activated human macrophages: posttranslational regulation by pyrrolidine dithiocarbamate; Thomas SR et al.; Induction of the heme-containing indoleamine 2,3-dioxygenase (IDO) by IFN-gamma is implicated in anti-microbial and pro-inflammatory activities of human macrophages . Antioxidants can modulate the expression of immune and inflammatory genes, and pyrrolidine dithiocarbamate (PDTC) is a frequently used antioxidant to inhibit the transcription factor NF-kappaB . Here we show that IFN-gamma treatment of human monocyte-derived macrophages (hMDMs) increased the proportion of oxidized glutathione . PDTC attenuated this increase and inhibited IDO activity, although it increased IDO protein expression and did not affect IDO mRNA expression and enzyme activity directly . Other antioxidants, 2-ME, ebselen, and t-butyl hydroquinone, inhibited IDO protein expression . Similar to PDTC, the heme biosynthesis inhibitor succinylacetone (SA) and the iron-chelator pyridoxal isonicotinoyl hydrazone inhibited cellular IDO activity without affecting protein expression, whereas addition of hemin or the heme precursor delta-aminolevulinic acid increased IDO activity . Also, incubation of IFN-gamma-activated hMDM with delta-{(14)C}-aminolevulinic acid resulted in the incorporation of label into immunoprecipitated IDO, a process inhibited by PDTC and SA . Furthermore, supplementation of lysates from PDTC- or SA-treated hMDM with hemin fully restored IDO activity to control levels, and hemin also reversed the inhibitory action of SA but not PDTC in intact cells . Together these results establish a requirement for de novo heme synthesis for IDO activity in IFN-gamma-activated hMDM . They show that, similar to other pro-inflammatory proteins, the activity of IDO is modulated by antioxidants though in the case of PDTC this takes place posttranslationally, in part by limiting the availability of heme for the formation of holo-IDO. Bioresour Technol, 2001 Jul, 78(3), 313 - 6 Increased biogas production using microbial stimulants; Singh S et al.; Laboratory studies were undertaken to evaluate the effect of microbial stimulants Aquasan and Teresan, on biogas yields from cattle dung and combined residues of cattle dung and kitchen waste, respectively . The addition of single dose of Aquasan at the rate of 10, 15 and 20 ppm to cattle dung on the first day of incubation resulted in increased gas yields ranging between 45.1 and 62.1 l/kg dry matter . Subsequent addition of Aquasan at 15 and 20 ppm dosage after a period of 15 days increased the gas yields by 15-16% . The gas production was found to be optimum at a dosage level of 15 ppm and was 39% and 55% higher with single and dual additions, respectively, than untreated cattle dung . In another bench scale study (1:1 dry matter) the addition of Teresan at 10 ppm concentration to the mixed residues of cattle dung and kitchen wastes at different solids concentration, produced 34.8% more gas (272.4 l/kg d.m.) than the uninoculated mixture at 15% TS concentration (202.4 l/kg d.m.). Ground Water, 2001 May-Jun, 39(3), 391 - 400 An assessment of a mesocosm approach to the study of microbial respiration in a sandy unsaturated zone; Hendry MJ et al.; Microbial respiration rates were determined through a 3.2 m thick, sandy unsaturated zone in a 2.4 m diameter x 4.6 m high mesocosm . The mesocosm was maintained under near constant temperature (18 degrees to 23 degrees C) and reached steady moisture content conditions after several hundred days . Soil-gas CO2 concentrations in the mesocosm ranged from 0.09% to 3.31% and increased with depth . Respiration rates within the mesocosm were quantified over a 342-day period using measured CO2 concentrations and a transient, one-dimensional finite-element model . Microbial respiration rates were 2 x 10(-1) micrograms C.g-1.d-1 throughout most of the system, but decreased to 10(-4) to 10(-3) micrograms C.g-1.d-1 within the capillary fringe . Microbial respiration rates were also determined in minicosms (500 g sample mass) over a range in temperatures (4 degrees to 30 degrees C) and volumetric moisture contents (0.044 to 0.37) . The functional dependence of CO2 production on temperature and soil-moisture content was similar for the two scales of laboratory observation . Respiration rates in the minicosms, for temperatures and moisture contents in the mesocosm, were up to an order of magnitude greater than those determined for the mesocosm . The higher respiration rates in the minicosms, compared to the mesocosm, were attributed to greater disturbance of the samples and to shorter acclimation time in the minicosms . Extrapolating the laboratory respiration rates to field conditions yielded rates that were two to three orders of magnitude greater than rates previously determined in situ for C-horizon material . Results show that in situ microbial reaction rates determined using disturbed samples in minicosms and mesocosms yielded respiration rates that greatly exceeded field conditions . Mesocosms can, however, provide a useful environment for conducting process-related research in unsaturated environments. Science, 2001 May 4, 292(5518), 917 - 20 Production of refractory dissolved organic matter by bacteria; Ogawa H et al.; Most of the oceanic reservoir of dissolved organic matter (DOM) is of marine origin and is resistant to microbial oxidation, but little is known about the mechanisms of its formation . In a laboratory study, natural assemblages of marine bacteria rapidly (in <48 hours) utilized labile compounds (glucose, glutamate) and produced refractory DOM that persisted for more than a year . Only 10 to 15% of the bacterially derived DOM was identified as hydrolyzable amino acids and sugars, a feature consistent with marine DOM . These results suggest that microbial processes alter the molecular structure of DOM, making it resistant to further degradation and thereby preserving fixed carbon in the ocean. Immunol Res, 2000, 22(2-3), 319 - 41 Nitric oxide synthase 2 and cyclooxygenase 2 interactions in inflammation; Weinberg JB; Nitric oxide (NO) and prostaglandin (PG) E2 produced by NO synthase type 2 (NOS2) and cyclooxygenase type 2 (COX2), respectively, are important mediators in inflammation . There is much information regarding their roles in models of inflammation in mice and in humans with diseases such as rheumatoid arthritis (RA) . A variety of stimuli including cytokines, microbial components, immune complexes, and mechanical stress can induce both NOS2 and COX2 mRNA transcription and protein synthesis and enhance inflammation . This has been demonstrated in both mice and humans . NOS2-specific inhibitors reduce inflammation in mice, and COX2-specific inhibitors reduce inflammation in mice and in humans . There is significant cross-talk between PGE2/NO and COX2/NOS2 . Treatments that inhibit both NOS2 and COX2 should provide the most potent antiinflammatory effects. Immunol Res, 2000, 22(2-3), 137 - 46 Immunoglobulin in the control of complement action; Frank MM et al.; Complement is a critical element of innate immunity, protecting individuals from a wide variety of microbial infections . This group of proteins is responsible for many features of inflammation and tissue damage . Because of its ability to mediate autoimmune tissue damage and to destroy host tissues, it is under tight regulation with many circulating and cell-membrane-bound complement regulatory proteins . The function of much of the circulating immunoglobulin has never been defined . We have advanced the hypothesis that one function of circulating immunoglobulin is to down-regulate complement attack on host tissues in the presence of anti-self antibody . The data to support this hypothesis are reviewed . The data are consistent with the suggestion that one mechanism of action of intravenous immunoglobulin, used to treat patients with a variety of autoimmune diseases, is prevention of complement-mediated attack on host tissues. Boll Chim Farm, 2001 Jan-Feb, 140(1), 40 - 5 Evaluation of the physico-chemical properties of a new polysaccharide gum from Prosopis africana; Adikwu MU et al.; The gum obtained from the ripe seeds of Prosopis africana was processed to compendial standard for plant gums and characterised . Toxicological studies of the polysaccharide on mice showed the material to be safe . The material hydrates slowly in aqueous media to form a colloidal dispersion . Swelling studies on the gum shows that the gum has a higher swelling capacity than methylcellulose . Rheological studies showed that the material is more viscous than tragacanth gum at equivalent concentrations . Acid hydrolysis and thin layer chromatography of the resulting hydrolysates showed that the gum contains glucose, fructose, galactose and xylose as the monosaccharide components . Microbial tests showed the gum to contain 8.26 x 10(4) viable cells per gram when freshly prepared . Other properties of the gum evaluated includes; melting or charring temperature, optical properties, true density, ash values, element content as well as its reactions with lead subacetate solution and 0.02 M iodine. J Periodontol, 2001 Apr, 72(4), 517 - 25 Apoptosis in chronic adult periodontitis analyzed by in situ DNA breaks, electron microscopy, and immunohistochemistry; Gamonal J et al.; BACKGROUND: Apoptosis is an evolutionary form of physiological cell death . Previous studies suggest that apoptosis is involved in the pathogenesis of periodontal diseases . Therefore, we studied the apoptotic events in the gingival tissue of chronic adult periodontitis patients . METHODS: Gingival tissue biopsies from 22 patients with chronic adult periodontitis and from 11 healthy controls were obtained . Criteria for patient inclusion in the periodontitis group were a minimum of 14 natural teeth, excluding third molars, with at least 10 posterior teeth; 5 to 6 sites with probing depth > or = 5 mm; attachment loss > or = 3 mm; and extensive radiographic bone loss . The control group included healthy subjects with no prior history of periodontal disease . Apoptosis was determined using the terminal TdT-mediated dUTP-biotin nick end labeling (TUNEL) technique; electron microscopic analysis; and expression of Caspase-3, Fas, FasL, Bcl-2, and p53 by immunohistochemistry . RESULTS: TUNEL-positive cells and cells exhibiting chromatin condensation by electron microscopy were observed in the inflammatory infiltrate of biopsies obtained from periodontitis patients . Most of the TUNEL-positive cells belonged to neutrophil cell populations as they were stained with anti-myeloperoxidase . Positive staining for active-caspase 3, Fas, FasL, and p53 was only observed in the inflammatory infiltrate from periodontitis biopsies, whereas Bcl-2 cells were present in both periodontitis patients and healthy controls . CONCLUSIONS: Our findings establish that apoptosis is induced in the periodontal tissue by host and microbial factors and support the hypothesis that apoptotic mechanisms could be implicated in the inflammatory process associated with gingival tissue destruction observed in adult periodontitis patients. Environ Toxicol Chem, 2001 May, 20(5), 1012 - 21 Metabolism of the polycyclic aromatic hydrocarbon fluoranthene by the polychaete Capitella capitata species I; Forbes VE et al.; Previous studies have shown that infaunal deposit feeders may enhance the loss of organic contaminants from sediments . However, the extent to which this occurs as a result of sediment microbial stimulation, porewater flushing, or biotransformation by infauna remains unclear . The purpose of this study was to determine whether the infaunal polychaete Capitella sp . I is able to metabolize the polycyclic aromatic hydrocarbon (PAH) fluoranthene and to provide an initial characterization of the metabolites produced . Our results showed that Capitella sp . I is able to metabolize fluoranthene to more hydrophilic products and that, after 24 h in clean sediment, fluoranthene could no longer be detected in worm tissues whereas a number of fluoranthene-derived metabolites were present . None of the metabolites released or retained by worms resembled known bacterial metabolites, suggesting that Capitella, and not bacteria associated with its gut or body surface, were responsible for the biotransformation of fluoranthene in our system . On the basis of ultraviolet maxima, peak shape, relative height, and order of elution, tentative identities of two metabolites (i.e., 3- and 8-hydroxyfluoranthene) are proposed . The results demonstrate that, in addition to their effects on sediment geochemical properties, infaunal polychaetes such as Capitella can enhance the degradation of sediment-associated contaminants by directly metabolizing them. Trends Microbiol, 2001 May, 9(5), 206 - 8 The meaning and impact of the human genome sequence for microbiology; Relman DA et al.; The characterization of life is immeasurably enhanced by determination of complete genome sequences . For organisms that engage in intimate interactions with others, the genome sequence from one participant, and associated tools, provide unique insight into its partner . We discuss how the human genome sequence will further our understanding of microbial pathogens and commensals, and vice versa . We also propose criteria for implicating a host gene in microbial pathogenesis, and urge consideration of a'second human genome project'. FEMS Immunol Med Microbiol, 2001 Apr, 30(3), 249 - 52 The immunomodulatory effects of gentamicin, imipenem, piperacillin and amphotericin B on LAK effector function in vitro; Rahman MU et al.; An understanding of the immunomodulating effects of anti-microbial regimens on recombinant interleukin-2 (rIL-2) induced peripheral leukocyte function, i.e . lymphokine-activated killer (LAK)-cell efficacy, would be clinically useful in the selection of commonly employed bone marrow transplantation (BMT) antibiotics to avoid post-transplant complications and optimize anti-microbial, anti-viral, anti-tumor therapies . In this report we evaluated the modulatory effects of a number of antibiotics used in BMT on LAK-cell cytotoxicities, in vitro . Our data showed that, even at serum trough titer, amphotericin B was significantly (P < or =0.05) immunostimulatory, whereas gentamicin, imipenem, and piperacillin, individually, were significantly (P < or =0.05) immunosuppressive . Statistical analysis detected no modulation due to aztreonam, amikacin, cotrimoxazole, or ceftazidime, or any of the six cephalosporins tested at molar equivalent concentration . We conclude that certain antibiotics may be more suitable for infection prone BMT hosts. Int J Parasitol, 2001 May 1, 31(5-6), 443 - 52 The biology of kinetoplastid parasites: insights and challenges from genomics and post-genomics; Gull K; Kinetoplastid parasites exhibit a rich and diverse biology which mirrors many of the most interesting topics of current interest and study in the broader biological sciences . These evolutionarily ancient organisms possess intriguing mechanisms for control of gene expression, and exhibit complex patterns of cell morphogenesis orchestrated by an internal cytoskeleton . Their cell shapes change during a set of complex cell type differentiations in their life cycles . These differentiations are intimately linked to interactions with mammalian hosts or insect vectors, and often, these differentiations appear central to the successful transfer of the parasite between vector and host, and host and vector . The basics of this rich and complex cell and life cycle biology were described (with often rather forgotten clarity and prescience) in the early period of the last century . The last 30 years have seen major developments in our understanding of this biology . Ultrastructural differences in the various cells of the life cycle stages of Trypanosoma brucei, Trypanosoma cruzi and the various Leishmania species have been documented, and such studies have proven highly informative in defining important aspects of parasite adaptation . They have also proven to be a rich source of information for defining unusual aspects of parasite cell biology, novel organelles and cell architecture . This ultrastructural cell biology has been mirrored in a set of biochemical explanations defining unusual aspects of metabolism, surface molecules, and organelles . Finally, the application of molecular biology to these parasites revealed fascinating layers of complexity in the control of gene expression . These molecular studies have given us particular insights into polycistronic transcription, trans-splicing, RNA editing and gene rearrangements during antigenic variation . In contrast to other microbial systems, these cell biological, biochemical and molecular studies have not been greatly aided by insights gained from genetics--the diploid nature of the genome has discouraged the application of selectional genetics, mutant isolation and analysis . This is an important fact, since in general, it means that we have only recently started to analyse the phenotypes of mutants produced in the context of reverse genetics . In the following, I will argue that this lack of investment in the analysis of mutant phenotype is just one of the challenges that will need to be met if we are to gain the expected added value from the parasite genome projects . In this presentation, I will use some of the current areas of interest in the biology of T . brucei, T . cruzi and the Leishmania species to rehearse some of the insights and challenges that are likely to stem from the application of genomics and post-genomic studies to the kinetoplastid parasites . In some cases, I will exemplify points by illustrations from my laboratory's work, interests and hypotheses . The presentation slants therefore towards T . brucei biology, however, in each case the reader will, no doubt, see the generalities of application to other kinetoplastid parasites. J Autoimmun, 2001 May, 16(3), 369 - 71 From reactive arthritis to rheumatoid arthritis; Toivanen P; Reactive arthritis was initially described as a sterile synovitis, without microbial components present in the joint tissue . It has, however, become evident that bacterial degradation products, and even bacterial DNA, are present in the synovium of patients with this disease . Since intestinal pathogens are important causes of reactive arthritis, and since cellular homing allows transport of bacterial products from the gut to synovium, we have approached the etiology of rheumatoid arthritis from this point of view . A series of observations has led to a hypothesis that patients with rheumatoid arthritis might favour, for genetic reasons, intestinal bacteria which are capable of inducing arthritis . In the long-run, with continuous seeding of bacterial products from the gut, the synovial inflammation is followed by erosion, exposition of cartilage antigens, and autoimmunity . J Autoimmun, 2001 May, 16(3), 319 - 26 Induction of autoimmunity through bystander effects . Lessons from immunological disorders induced by heavy metals; Fournie GJ et al.; Autoreactive T cells exist in healthy individuals and represent a potential reservoir of pathogenic effectors which, when stimulated by microbial adjuvants, could trigger an autoimmune disease . Experimental studies have indicated that xenobiotics, well defined from a chemical point of view, could promote the differentiation of autoreactive T cells towards a pathogenic pathway . It is therefore theoretically possible that compounds present in vaccines such as thiomersal or aluminium hydroxyde can trigger autoimmune reactions through bystander effects.Mercury and gold in rodents can induce immunological disorders with autoimmune reactions . In vitro, both activate signal transduction pathways that result in the expression of cytokines, particularly of IL-4 and IFNgamma . In a suitable microenvironment heavy metals could therefore favour the activation of autoreactive T cells . In that respect, genetic background is of major importance . Genome-wide searches in the rat have shown that overlapping chromosomal regions control the immunological disorders induced by gold salt treatment, the development of experimental autoimmune encephalomyelitis and the CD45RC(high)/CD45RC(low)CD4(+)T cells balance . The identification and functional characterization of genes controlling these phenotypes may shed light on key regulatory mechanisms of immune responses . This should help to improve efficacy and safety of vaccines . J Autoimmun, 2001 May, 16(3), 293 - 302 Structural basis of molecular mimicry; Wucherpfennig KW; Infectious agents are thought to play an important role in the development of autoimmune diseases . Sequence similarity between infectious agents and self-proteins (molecular mimicry) has been proposed as a mechanism for the induction of autoimmunity {1} . However, it has been difficult to identify microbial peptides that activate autoreactive T cells using conventional sequence alignments . This chapter reviews progress made in the identification of such microbial peptides based on the analysis of structural features that are important for TCR recognition of MHC-bound peptides {2} . Biochemistry (Mosc), 2001 Mar, 66(3), 267 - 81 alpha-Glucosidases; Krasikov VV et al.; This review highlights the main properties of mammalian, plant, and microbial alpha-glucosidases . Special attention is given to the classification of these enzymes, possible catalytic mechanisms, their tertiary structure, and the structure of major inhibitors . Experimental data on the elucidation of amino acid residues essential for catalysis are also discussed. Acta Paediatr Suppl, 2001 Mar, 90(436), 19 - 21 Trophic feeding of the preterm infant; McClure RJ; Trophic feeding is the practice of feeding minute volumes of enteral feeds in order to stimulate the development of the immature gastrointestinal tract of the preterm infant This paper reviews the randomized controlled studies that have examined the physiological and clinical responses to trophic feeding of the preterm infant . Trophic feeding alters gastrointestinal disaccharidase activity, hormone release, blood flow, motility and microbial flora . Clinical benefits appear to include improved milk tolerance, greater postnatal growth, reduced systemic sepsis and shorter hospital stay . There is currently no evidence of any adverse effects following trophic feeding. Transplantation, 2001 Mar 27, 71(6), 796 - 801 Vaccinia virus complement control protein is capable of protecting xenoendothelial cells from antibody binding and killing by human complement and cytotoxic cells; Al-Mohanna F et al.; BACKGROUND: Vaccinia virus complement control protein (VCP) was the first secretory microbial protein shown to have structural similarity to the family of complement control proteins . VCP can block both the classical and alternate complement pathways . Recently, VCP has been shown to bind to heparin, and this property contributes to separate functions, making the molecule a multifunctional protein . METHODS: VCP prepared from a natural infection of RK-13 cells with vaccinia virus was purified to homogeneity . Cultured pig aortic endothelial cells (PAECs) were mixed with human serum, anti-Gal alpha1,3 Gal antibody, neutrophils, or natural killer (NK) cells in the presence or absence of VCP and either direct binding of FITC-labeled antibody or killing by cytotoxic cells was estimated . RESULTS: Our cell culture studies demonstrate that VCP blocks complement-mediated killing of PAECs by human serum in a dose-dependent manner . We also demonstrate that VCP is capable of blocking Gal alpha1,3 Gal binding sites on PAECS . Surprisingly, VCP effectively blocked interactions between PAECs and cytotoxic cells such as human naive neutrophils and NK cells . CONCLUSION: VCP is a novel protein amongst the complement control protein family and can, not only block xenorejection by inhibiting complement but also by blocking killing by cytotoxic cells. Environ Sci Technol, 2001 Apr 15, 35(8), 1599 - 603 CoIIIEDTA- reduction by Desulfovibrio vulgaris and propagation of reactions involving dissolved sulfide and polysulfides; Blessing TC et al.; The migration of 60Co, dominantly via transport of Co-EDTA complexes, into surface water and groundwater is a recognized concern at many nuclear production and storage sites . Reduction of CoIIIEDTA- to CoIIEDTA2- should decrease the mobility of 60Co in natural environments by stimulating ligand displacement with Fe(III) or Al(III) or by precipitation of CoSx in sulfidic environments . In this study, we examine direct (enzymatic) and indirect (metabolite) reduction processes of CoIIIEDTA- by the sulfate-reducing bacterium Desulfovibrio vulgaris . D . vulgaris reduces CoIIIEDTA- to CoIIEDTA2-, but growth using it as a terminal electron acceptor was not demonstrated . Rather than acting as a competing electron acceptor and limiting cobalt reduction, introducing sulfate with D . vulgaris enhances the reduction of CoIIIEDTA- as a result of sulfide production . Sulfide reduces CoIIIEDTA- in a pathway involving polysulfide formation and leads to a CoS precipitate . Thus, both direct and indirect (i.e., through the production of sulfide) microbial reduction pathways of CoIIIEDTA- may help to retard its migration within soils and waters. Water Res, 2001 May, 35(7), 1831 - 41 Hydrogen production in anaerobic reactors during shock loads--influence of formate production and H2 kinetics; Voolapalli RK et al.; In this article the role of hydrogen as a process monitoring tool in methanogenic systems was studied by considering the influence of several key system parameters . Hydrogen production was found to be influenced mainly by the inocula's source pH, and varied only slightly with external pH and HCO3- levels . When an inoculum adapted to above neutral conditions (pH > 7) was shocked, reducing equivalents were selectively channelled through formate, while high hydrogen production was noticed with acidically (pH < 6.5) adapted inocula . The results also revealed that the production of hydrogen or formate during shock loads was not strongly associated with microbial morphology (granules or flocs) as high electron fluxes were possible through either during acidogenesis . Shock load experiments in continuous reactors revealed that neither hydrogen nor formate accumulated to any significant degree, nevertheless digester recovery took a long time due to the slow kinetics of volatile fatty acid degradation . Selective formate production under neutral pH environments, coupled with high hydrogenotrophic activity, was found to be responsible for the dampened hydrogen response during the early phases of gradually shocked systems (step change) . Based on these results it appears that the role of hydrogen as a process monitoring tool has been overemphasised in the literature. Cleve Clin J Med, 2001 Apr, 68(4), 318 - 22 Legionnaires' disease: seek and ye shall find; Yu VL; Legionella pneumophila is among the top three or four microbial causes of community-acquired pneumonia, yet is often misdiagnosed and inadequately treated . New laboratory tests should simplify the diagnosis . Also, contrary to common perception, the disease is usually spread via aspiration of water from contaminated hot water distribution systems, not from air conditioning systems . The treatment of choice has shifted from erythromycin to the newer macrolides and quinolones . Routine culturing of the hospital water supply is a requisite first step in preventing hospital-acquired Legionnaires' disease. J Calif Dent Assoc, 2000 Mar, 28(3), 215 - 33 Global antibiotic resistance and its impact on the dental community; Pallasch TJ; There is significant evidence that the global problem of microbial resistance to antibiotics has reached the dental community both in our practices and our family lives . This paper will present a global overview of microbial resistance, discuss how this problem directly affects the dental community, and show what we can do to change the situation, both as concerned citizens and as dental health care practitioners. J Exp Bot, 2001 Mar, 52(Spec Issue), 487 - 511 Microbial interactions and biocontrol in the rhizosphere; Whipps JM; The loss of organic material from the roots provides the energy for the development of active microbial populations in the rhizosphere around the root . Generally, saproptrophs or biotrophs such as mycorrhizal fungi grow in the rhizosphere in response to this carbon loss, but plant pathogens may also develop and infect a susceptible host, resulting in disease . This review examines the microbial interactions that can take place in the rhizosphere and that are involved in biological disease control . The interactions of bacteria used as biocontrol agents of bacterial and fungal plant pathogens, and fungi used as biocontrol agents of protozoan, bacterial and fungal plant pathogens are considered . Whenever possible, modes of action involved in each type of interaction are assessed with particular emphasis on antibiosis, competition, parasitism, and induced resistance . The significance of plant growth promotion and rhizosphere competence in biocontrol is also considered . Multiple microbial interactions involving bacteria and fungi in the rhizosphere are shown to provide enhanced biocontrol in many cases in comparison with biocontrol agents used singly . The extreme complexity of interactions that can occur in the rhizosphere is highlighted and some potential areas for future research in this area are discussed briefly. J Exp Bot, 2001 Mar, 52(Spec Issue), 381 - 401 Roots: evolutionary origins and biogeochemical significance; Raven JA et al.; Roots, as organs distinguishable developmentally and anatomically from shoots (other than by occurrence of stomata and sporangia on above-ground organs), evolved in the sporophytes of at least two distinct lineages of early vascular plants during their initial major radiation on land in Early Devonian times (c . 410-395 million years ago) . This was some 15 million years after the appearance of tracheophytes and c . 50 million years after the earliest embryophytes of presumed bryophyte affinity . Both groups are known initially only from spores, but from comparative anatomy of extant bryophytes and later Lower Devonian fossils it is assumed that, during these times, below-ground structures (if any) other than true roots fulfilled the functions of anchorage and of water and nutrient acquisition, despite lacking an endodermis (as do the roots of extant Lycopodium spp.) . By 375 million years ago root-like structures penetrated almost a metre into the substratum, greatly increasing the volume of mineral matter subject to weathering by the higher than atmospheric CO(2) levels generated by plant and microbial respiration in material with restricted diffusive contact with the atmosphere . Chemical weathering consumes CO(2) in converting silicates into bicarbonate and Si(OH)(4) . The CO(2) consumed in weathering ultimately came from atmospheric CO(2) via photosynthesis and respiration; this use of CO(2) probably accounts for most of the postulated 10-fold decrease in atmospheric CO(2) from 400-350 million years ago, with significant effects on shoot evolution . Subsequent evolution of roots has yielded much-branched axes down to 40 microm diameter, a lower limit set by long-distance transport constraints . Finer structures involved in the uptake of nutrients of low diffusivity in soil evolved at least 400 million years ago as arbuscular mycorrhizas or as evaginations of "roots" ("root hairs"). J Org Chem, 2001 May 4, 66(9), 2948 - 56 Chemoenzymatic synthesis of neoglycopeptides: application to an alpha-Gal-terminated neoglycopeptide; Ramos D et al.; A novel methodology for the enzymatic preparation from suitably derivatized oligosaccharides of N-linked neoglycopeptides using the microbial glutaminyl-peptide gamma-glutamyl transferase, transglutaminase (TGase), is described . N-Allyl glycosides of various oligosaccharides were photochemically coupled with cysteamine to yield amino-terminated thioether spacers, which were accepted by transglutaminase to transamidate the side-chain gamma-carboxamide group in the dipeptide Z-Gln-Gly. Mediators Inflamm, 2001 Feb, 10(1), 13 - 9 Inhalation of (1-->3)-beta-D-glucan causes airway eosinophilia; Fogelmark B et al.; BACKGROUND: Moulds are present in a variety of environments and aerosols of fungal spores are generated when mouldy materials are handled . Molds contain (1-->3)-beta-D-glucan, a polyglucose which is present in the cell wall of fungi, certain bacteria and plants . AIM: This study was undertaken to investigate the cellular inflammatory response in the lung after inhalation of (1-->3)-beta-D-glucan and bacterial endotoxin . METHODS: Guinea pigs were exposed daily to an aerosol of pure (1-->3)-beta-D-glucan and pure endotoxin for five weeks . Lung lavage and lung interstitial cell preparations were done and the inflammatory cells counted . Histological sections were prepared from the trachea . RESULTS: There was an increase in eosinophil numbers in lung lavage, lung interstitium, and the airway epithelium of animals exposed to (1-->3)-beta-D-glucan . In animals simultaneously exposed to endotoxin, there was no increase in eosinophils . In the lung interstitium, (1-->3)-beta-D-glucan exposure caused an increase in lymphocytes, which was not found after endotoxin exposure . Endotoxin exposure caused an increase in neutrophils and macrophages in lung lavage, which was not found after (1-->3)-beta-D-glucan exposure . CONCLUSIONS: The results support previous findings that (1-->3)-beta-D-glucan causes a different response in the airways as compared to endotoxin . Endotoxin modulated the increase in eosinophils caused by (1-->3)-beta-D-glucan exposure, suggesting a complex interaction between the microbial cell wall components. Rev Immunogenet, 2000, 2(1), 95 - 104 HLA, molecular mimicry and multiple sclerosis; Liblau R et al.; Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system in which an autoimmune response most probably contributes to pathogenesis . To date, the best characterized susceptibility-associated gene has been mapped to the HLA complex . The HLA-DRB1*1501 - DRB5*0101 - DQA1*0102 - DQB1*0602 haplotype is both associated and linked to MS in different ethnic groups . The locus within the HLA class II region encoding the MS-susceptibility gene is under intensive investigation . Epidemiological studies, however, have suggested that environmental antigens also play a critical role in MS pathogenesis . One of the ways a pathogen could trigger autoimmune disease is via immunological cross-reactivity or molecular mimicry . This concept argues that a microbial peptide with certain degree of homology to a self peptide can stimulate pathogenic self-reactive specific T cells to cause an autoimmune disease . Many microbial agents have regions of sequences that may serve as binding motifs for HLA-DR2 . HLA genetics and molecular mimicry may therefore be intimately interlinked in the disease process . In the present review, we focus on the HLA association with MS and the role of microbial antigens in MS, with special reference to the molecular mimicry hypothesis. J N J Dent Assoc, 2000 Spring, 71(2), 14 - 5, 18-9, 22-3 passim Global antibiotic resistance and its impact on the dental community; Pallasch TJ; There is significant evidence that the global problem of microbial resistance to antibiotics has reached the dental community both in our practices and our family lives . This paper will present a global overview of microbial resistance, discuss how this problem directly affects the dental community, and show what we can do to change the situation, both as concerned citizens and as dental health care practitioners. J Calif Dent Assoc, 2000 Dec, 28(12), 933 - 41 Xerostomia--clinical evaluation and treatment in general practice; Daniels TE et al.; Xerostomia is a common symptom with various causes that, if ignored, can lead to serious oral consequences . Clinical evaluation of patients complaining of dry mouth must include some additional history and specific examination of the salivary glands, oral mucosa, and teeth . Additional evaluation may include consultation with the patient's physician, request for microbial culture, or labial salivary gland biopsy . No one form of treatment for patients with chronic xerostomia is sufficient, but comprehensive treatment is effective in improving patient oral comfort and function and preventing unnecessary loss of teeth . This treatment must include ongoing dental caries prevention and treatment, salivary flow stimulation, recognition and treatment of oral candidiasis, selective use of saliva substitutes, and possible changes in the patients' prescription and nonprescription drug use. Environ Microbiol, 2001 Feb, 3(2), 123 - 30 Bacterially mediated precipitation in marine stromatolites; Paerl HW et al.; Stromatolites are laminated, lithified (CaCO3) sedimentary deposits formed by precipitation and/or sediment accretion by cyanobacterial-bacterial mat communities . Stromatolites have been associated with these communities as far back as the Precambrian era some 2+ billion years ago . The means by which microbial communities mediate the precipitation processes have remained unclear, and are the subject of considerable debate and speculation . Two alternative explanations for microbially mediated precipitation include: (i) cyanobacterial photosynthesis increases pH in a system supersaturated in respect of CaCO3, resulting in CaCO3 precipitation and then laminated lithification, and (ii) decomposition of cyanobacterial extracellular organic matter (e.g . sheaths, mucilage and organic acids) by microheterotrophs leads to release of organic-bound Ca2+ ions and CaCO3 precipitation . We evaluated these explanations by examining metabolically active, lithifying stromatolitic mat communities from Highborne Cay, Bahamas, using microautoradiography . Microautoradiographic detection of 14CO2 fixation and 3H organic matter (D-glucose and an amino acid mixture) utilization by photosynthetically active cyanobacteria and microheterotrophs, combined with community-level uptake experiments, indicate that bacteria, rather than cyanobacteria are the dominant sites of CaCO3 deposition . In the oligotrophic waters in which stromatolites exist, microheterotrophs are reliant on the photosynthetic community as a main source of organic matter . Therefore, autotrophic production indirectly controls microbially mediated precipitation and stromatolite formation in these shallow marine environments. Int J Syst Evol Microbiol, 2001 Mar, 51(Pt 2), 527 - 33 Dechloromonas agitata gen . nov., sp . nov . and Dechlorosoma suillum gen . nov., sp . nov., two novel environmentally dominant (per)chlorate-reducing bacteria and their phylogenetic position; Achenbach LA et al.; Previous studies on the ubiquity and diversity of microbial (per)chlorate reduction resulted in the isolation of 20 new strains of dissimilatory (per)chlorate-reducing bacteria . Phylogenetic analysis revealed that all of the isolates were members of the Proteobacteria with representatives in the alpha-, beta- and gamma-subclasses . The majority of the new isolates were located in the beta-subclass and were closely related to each other and to the phototrophic Rhodocyclus species . Here an in-depth analysis of these organisms which form two distinct monophyletic groups within the Rhodocyclus assemblage is presented . Two new genera, Dechloromonas and Dechlorosoma, are proposed for these beta-subclass lineages which represent the predominant (per)chlorate-reducing bacteria in the environment . The type species and strains for these new genera are Dechloromonas agitata strain CKBT and Dechlorosoma suillum strain PST, respectively. Anal Biochem, 2001 May 1, 292(1), 34 - 9 In situ assays of fungal enzymes in cells permeabilized by osmotic shock; Sestak S et al.; Permeabilization of yeast and other fungal cells by osmotic shock enabled the in situ assays of intracellular plasma membrane-bound enzymes, such as beta-1,3-glucan synthase, chitin synthase, and Na(+)/K(+) ATPase as well as the soluble, cytoplasmic enzymes, such as lactate dehydrogenase and alpha-glucosidase . The permeabilization was accomplished by rapid changes in osmolarity of the washing buffer at 0 degrees C whereby 0.5-3.5 M glycerol, sorbitol, and/or mannitol and/or 1 M KCl could be used as the osmolytes . No appreciable leakage of intracellular proteins occurred during the permeabilization procedure . The described procedure caused practically complete cell permeabilization while avoiding treatments with organic solvents, detergents, and other xenobiotics currently used for the permeabilization of microbial cells. Ann Dermatol Venereol, 2001 Mar, 128(3 Pt 2), 307 - 11 {Erysipelas . Clinicopathological classification and terminology}; Grosshans E; Erysipelas and necrotizing fasciitis are the words used to qualify 2 well-defined aspects of acute microbial dermohypodermal infection . According to the literature a third word, "cellulitis" is used to describe a large variety of inflammatory conditions of soft tissues, either infectious or not . The authors who advocate using this word consider either that an infectious cellulitis is a clinical variant differing from erysipelas or fasciitis, or that it describes the whole spectrum of acute microbial infections of soft tissues, including these 2 entities . This term, whatever its meaning, has no anatomical or histopathological validation . It should be definitively deleted and replaced by "dermohypodermal infection". Mol Biol Evol, 2001 May, 18(5), 829 - 39 Pseudogenes, junk DNA, and the dynamics of Rickettsia genomes; Andersson JO et al.; Studies of neutrally evolving sequences suggest that differences in eukaryotic genome sizes result from different rates of DNA loss . However, very few pseudogenes have been identified in microbial species, and the processes whereby genes and genomes deteriorate in bacteria remain largely unresolved . The typhus-causing agent, Rickettsia prowazekii, is exceptional in that as much as 24% of its 1.1-Mb genome consists of noncoding DNA and pseudogenes . To test the hypothesis that the noncoding DNA in the R . prowazekii genome represents degraded remnants of ancestral genes, we systematically examined all of the identified pseudogenes and their flanking sequences in three additional Rickettsia species . Consistent with the hypothesis, we observe sequence similarities between genes and pseudogenes in one species and intergenic DNA in another species . We show that the frequencies and average sizes of deletions are larger than insertions in neutrally evolving pseudogene sequences . Our results suggest that inactivated genetic material in the Rickettsia genomes deteriorates spontaneously due to a mutation bias for deletions and that the noncoding sequences represent DNA in the final stages of this degenerative process. Appl Environ Microbiol, 2001 May, 67(5), 2354 - 9 DNA extraction from soils: old bias for new microbial diversity analysis methods; Martin-Laurent F et al.; The impact of three different soil DNA extraction methods on bacterial diversity was evaluated using PCR-based 16S ribosomal DNA analysis . DNA extracted directly from three soils showing contrasting physicochemical properties was subjected to amplified ribosomal DNA restriction analysis and ribosomal intergenic spacer analysis (RISA) . The obtained RISA patterns revealed clearly that both the phylotype abundance and the composition of the indigenous bacterial community are dependent on the DNA recovery method used . In addition, this effect was also shown in the context of an experimental study aiming to estimate the impact on soil biodiversity of the application of farmyard manure or sewage sludge onto a monoculture of maize for 15 years. Appl Environ Microbiol, 2001 May, 67(5), 2129 - 35 Comparison of logistic regression and linear regression in modeling percentage data; Zhao L et al.; Percentage is widely used to describe different results in food microbiology, e.g., probability of microbial growth, percent inactivated, and percent of positive samples . Four sets of percentage data, percent-growth-positive, germination extent, probability for one cell to grow, and maximum fraction of positive tubes, were obtained from our own experiments and the literature . These data were modeled using linear and logistic regression . Five methods were used to compare the goodness of fit of the two models: percentage of predictions closer to observations, range of the differences (predicted value minus observed value), deviation of the model, linear regression between the observed and predicted values, and bias and accuracy factors . Logistic regression was a better predictor of at least 78% of the observations in all four data sets . In all cases, the deviation of logistic models was much smaller . The linear correlation between observations and logistic predictions was always stronger . Validation (accomplished using part of one data set) also demonstrated that the logistic model was more accurate in predicting new data points . Bias and accuracy factors were found to be less informative when evaluating models developed for percentage data, since neither of these indices can compare predictions at zero . Model simplification for the logistic model was demonstrated with one data set . The simplified model was as powerful in making predictions as the full linear model, and it also gave clearer insight in determining the key experimental factors. Bioresour Technol, 2001 Jan, 76(1), 57 - 61 Laboratory composting of extruded poly(lactic acid) sheets; Ghorpade VM et al.; Composting of extruded poly(lactic acid) (PLA) in combination with pre-composted yard waste in a laboratory composting system was studied . Yard waste and PLA mixtures containing 0%, 10%, or 30% PLA (dry weight basis) were placed in composting vessels for four weeks . Exhaust gases were analyzed for carbon dioxide concentration twice per week . After the first week, significantly greater (P < 0.05) amounts of carbon dioxide were generated in vessels with 10% or 30% PLA than in control (0% PLA) vessels . Data indicated that microbial degradation of PLA occurred . There was no significant difference (P > 0.05) in carbon dioxide emission between 10% and 30% PLA mixtures . Compost pH dropped (from 6.0 to 4.0) after 4 weeks of composting for 30% PLA, but remained unchanged (6.3) for 0% or 10% PLA . Most likely, in the case of 30% PLA, substantial chemical hydrolysis and lactic acid generation lowered the compost pH . The lowered pH likely suppressed microbial activity, thus explaining the lack of difference in carbon dioxide emissions between 10% and 30% PLA mixtures . Gel permeation chromatography showed a notable decrease in PLA molecular weight as a result of composting . It was demonstrated that PLA can be efficiently composted when added in small amounts (<30% by weight) to pre-composted yard waste. Dtsch Tierarztl Wochenschr, 2001 Mar, 108(3), 131 - 5 {The species-specific feeding of rabbits in pet husbandry.}; Kamphues J; To meet nutrient demands as well as the species specific requirements of an animal it is absolutely necessary to know its nutrition physiology (KAMPHUES et al . 1999) . Characteristics of the nutrition physiology of rabbits include the anatomy of the intestinal tract (i.e . the teeth, the size of gut as well as the small intestine and colon), the special ingesting behaviour (selection, intensity of gnawing and chewing) and digestive processes within the intestinal tract (digestion by own as well as by microbial enzymes, processes of separation (producing soft faeces) and the excretion of digested or undigested nutrients (excretion via faeces or kidneys, quality of faeces) . In feeding pet rabbits it has to be recommended, that these species do not need concentrates, but ingredients with higher crude fiber contents due to their origin and their intestinal tract . Therefore these herbivorous species should be fed with hay, straw or vegetables and not with concentrates exclusively . If these components are not offered (an usual feeding practice in rabbits kept as companion animals), other products rich in crude fibre have to be fed . The offer of a pressed diet in cube form with long fibrous ingredients would be a possibility to upgrade a ration poor in crude fibre . To meet the gnawing requirement of the rabbits this cubes should be pressed intensively . Furthermore it is advisable to exchange ingredients of the mixed feed with a high energy content (i.e . sunflower seeds, nuts) for ingredients of lower energy density (i.e . oat hulls, pelleted ground hay) . Finally calcium oversupply has to be avoided because higher calcium intake may result in urolithiasis (calcium stones/concrements). Gene Ther, 2001 Jan, 8(2), 89 - 98 Clinical research results with dl1520 (Onyx-015), a replication-selective adenovirus for the treatment of cancer: what have we learned? Kirn D. Replication-selective microbial agents hold promise as a novel cancer treatment platform . dl1520 (Onyx-015), an E1B-55 kD gene-deleted adenovirus, was the first such genetically engineered agent to be tested in humans . Over 200 cancer patients have been treated to date on over 10 clinical trials (phases I-III) . The virus was generally well-tolerated at doses of up to 2 x 10(12) particles by intratumoral, intraperitoneal, hepatic arterial and intravenous administration; no maximally tolerated doses were identified by any route of administration . Viral replication was tumor-selective, and was documented after administration by all routes; replication was generally transient (<10 days), however, and was variable depending on tumor histology . single agent efficacy has been limited to date (0-14% local tumor regression rates) . in combination with chemotherapy, however, encouraging antitumoral activity has been demonstrated . these clinical research results demonstrate the potential of this novel treatment platform, as well as the hurdles to be overcome . novel replication-selective agents with improved potency are needed. Biotechnol Prog, 2001 Mar-Apr, 17(2), 304 - 10 Asymmetric ketone reduction with immobilized yeast in hexane: biocatalyst deactivation and regeneration; Griffin DR et al.; There is a need to develop methods for producing enantiomerically pure pharmaceuticals because the racemic mixtures made today will probably not be allowed in the future . Synthetic chiral catalysts are being developed for this purpose, as well as new product separation techniques . Another possible option is to use biocatalysts, such as purified enzymes or whole microbial cells, since these can result in the production of mostly a single enantiomer . This study emphasizes the use of alginate-entrapped yeast cells to catalyze the reduction of ketones as a model system . The emphasis is on the factors that might limit the reactivity of such cells, such as equilibrium conditions, substrate or product inhibition, solvent toxicity, loss of cell viability, or the degradation of intracellular levels of enzymes or cofactors.It was found that there was a progressive loss of catalytic activity of the immobilized yeast cells, which appeared to be mainly associated with a loss of cell viability and a decline of intracellular NAD(H) levels during the reaction . The other factors investigated did not have a large effect . A regeneration scheme was developed in order to replenish the intracellular NAD(H) lost during the reaction, which involved removing the biocatalyst from the reaction and supplying the cells with a nutrient source . This resulted in an increase in the NAD(H) to initial levels and also resulted in a maintenance of the ketone reduction rate over time. Microb Pathog, 2001 Apr, 30(4), 179 - 92 Identification of lysine decarboxylase as a mammalian cell growth inhibitor in Eikenella corrodens: possible role in periodontal disease; Levine M et al.; The pathogenesis of inflammatory periodontal disease was studied by examining the mechanism of HeLa and HL60 cell growth inhibition by cell-free saline-soluble extracts of Eikenella corrodens and bacterial plaque . Previous studies identified a protein (p80) as causing growth inhibition by E . corrodens extracts . After purification by two-dimensional SDS-PAGE, p80 was digested with protease lysC . Amino acid sequences were obtained and backtranslated for use as PCR primers . A 5840 nucleotide sequence containing a lysine decarboxylase gene was obtained from a Sau3 A1 genomic library of E . corrodens DNA . Lysine decarboxylase activity was present at physiologic pH in the E . corrodens extracts containing p80, and also in bacterial plaque . Both extracts caused growth inhibition by depleting lysine from cell culture media through conversion to cadaverine . Adding lysine, or immune goat IgG to a peptide derived from the active site sequence of E . corrodens lysine decarboxylase, retarded lysine depletion and growth inhibition . epsilon-Amino caproic acid specifically enhanced lysine decarboxylase activity at the low lysine concentration in HL60 cell culture media, and also increased the growth inhibition . Thus, lysine decarboxylases such as p80 inhibit growth by removing lysine from mammalian cell culture media . A new role for lysine decarboxylase activity in the microbial aetiology of periodontal disease is discussed . Cytokine Growth Factor Rev, 2001 Mar, 12(1), 91 - 105 Pleiotropic roles of formyl peptide receptors; Le Y et al.; FPR and FPRL1 belong to the seven-transmembrane, G protein-coupled chemoattractant receptor superfamily . Because of their capacity to interact with bacterial chemotactic formylated peptides, these receptors are thought to play a role in host defense against microbial infection . Recently, a variety of novel agonists have been identified for these receptors, including several host-derived endogenous molecules that are involved in proinflammatory responses . Most notably is the use of FPRL1 by at least three amyloidogenic protein and peptide ligands, the serum amyloid A (SAA), the 42 amino acid form of beta amyloid (Abeta(42)), and the prion peptide PrP106-126, to chemoattract and activate human phagocytic leukocytes . These new findings have greatly expanded the functional scope of the formyl peptide receptors and call for more in-depth investigation of the role of these receptors in pathophysiological conditions. Adv Drug Deliv Rev, 2001 Apr 25, 47(2-3), 197 - 207 Exogenous surfactant as a drug delivery agent; Haitsma JJ et al.; Pulmonary surfactant is a complex mixture of lipids and several specific surfactant proteins, which together render it with unique spreading properties and a dynamic surface tension behavior . These characteristics are heralded as ideal for a carrier of choice to instil therapeutic agents into the lung, because this combination enables high local therapeutic levels while minimizing systemic side-effects of the instilled agent . This review outlines the rationale to use exogenous surfactant in lung injury, including opening-up inaccessible regions of the lung to other therapeutic agents . Especially the combination of anti-microbial agents and surfactant offers an alternative for critically ill patients with pneumonia . Some caution is also indicated in combining surfactant with antibiotics without proper evaluation of possible interactions . Some other applications for surfactant as a carrier are discussed . Overall, the benefits of surfactant as a carrier warrants clinical trials and promises additional therapeutic tools for the clinician. Gene, 2001 Apr 4, 267(1), 13 - 22 The invertebrate growth factor/CECR1 subfamily of adenosine deaminase proteins; Charlab R et al.; Adenosine deaminase (ADA) catalyzes the hydrolysis of adenosine to inosine . Its lack determines severe combined immunodeficiency in mammals, possibly due to accumulation of extracellular adenosine, which induces apoptosis in lymphocytes (Franco et al., 1998) . Thus, presence of normal levels of ADA leads to normal growth and proliferation of lymphocytes . Several vertebrate and microbial ADA amino-acid sequences are known, with substantial similarity to each other . On the other hand, there are invertebrate growth factors as well as a candidate gene for the human cat eye syndrome (CECR1) (Riazi et al., 2000 . Genomics 64, 277-285), which share substantial similarity to each other, and also to ADA . In this study, we report the expression and ADA enzymatic activity of a cDNA from the salivary glands of Lutzomyia longipalpis, a blood-sucking insect, with substantial similarity to insect growth factors and to human CECR1 . We also demonstrate the existence of a subfamily of the adenosine deaminase family characterized by their unique amino-terminal region . Both Drosophila melanogaster and humans have both types of adenosine deaminases . Results indicate that these invertebrate proteins previously annotated as growth factors, as well as the human CECR1 gene product, may exert their actions through adenosine depletion . The different roles played by each type of adenosine deaminase in humans and Drosophila remains to be fully investigated. FEMS Microbiol Ecol, 2001 May, 35(3), 287 - 293 Expansion of the geographic distribution of a novel lineage of epsilon-Proteobacteria to a hydrothermal vent site on the Southern East Pacific Rise; Longnecker K et al.; The diversity associated with a microbial mat sample collected from a deep-sea hydrothermal vent on the Southern East Pacific Rise was determined using a molecular phylogenetic approach based on the comparison of sequences from the small subunit ribosomal RNA gene (16S rDNA) . The DNA was extracted from the sample and the 16S rDNA was amplified by PCR . Sixteen different phylotypes were identified by restriction fragment length polymorphism analysis; four phylotypes were later identified as putative chimeras . Analysis of the 16S rDNA sequences placed all the phylotypes within the Proteobacteria . The majority of the sequences (98%) were most closely related to a new clade of epsilon-Proteobacteria that were initially identified from an in situ growth chamber deployed on a deep-sea hydrothermal vent on the Mid-Atlantic Ridge in 1995 . The similarity between phylotypes identified from Atlantic and Pacific deep-sea hydrothermal vent sites indicates that this new clade of Proteobacteria may be endemic to and widely distributed among deep-sea hydrothermal vents. Neurosci Res, 2001 May, 40(1), 61 - 6 Comparison of the spinal anti-nociceptive effects of ES-242-1 and MK-801, two different NMDA antagonists, in rats; Hamada F et al.; The purpose of this study was to determine whether ES-242-1, a novel N-methyl-D-aspartate (NMDA) receptor antagonist of microbial origin, has anti-nociception at the spinal level and to evaluate how its anti-nociceptive effect differs from that of MK-801, a non-competitive NMDA receptor antagonist . Agents were injected intrathecally (0.1, 1.0 and 10 microg) through a previously implanted PE tube in rats . Formalin (2%, 100 microl) was injected subcutaneously into the left hindpaw 15 min after each antagonist administration . Licking time as a nociceptive behavior was measured in three stages after formalin-injection, such as early phase (0-9 min), late first phase (10-29 min) and late second phase (30-60 min) . In the early phase, the largest dose of ES-242-1 significantly decreased total licking time, although MK-801 did not show any significant reduction . With the treatment of 1.0 and 10 microg MK-801, total licking time in both late first and second phases was significantly suppressed, although the smallest dose (0.1 microg) of ES-242-1 showed a significant reduction in the late second phase . These results indicate that ES-242-1 is highly effective against tonic pain, such as inflammatory pain. PDA J Pharm Sci Technol, 2001 Mar-Apr, 55(2), 114 - 26 Retention of water-borne bacteria by membrane filters . Part III: Bacterial challenge tests on 0.1 micron rated filters; Sundaram S et al.; Clear performance differences were observed between different 0.1 micron rated filters in terms of their microbial removal efficiency when challenged with naturally occurring waterborne bacteria from a water source . Penetration occurred with three 0.1 micron rated "sterilizing grade" filter types tested, from three different filter manufacturers, that did not have a specific high titer reduction claim for Acholeplasma laidlawii . Bacteria shown to penetrate these 0.1 micron rated filters were quite similar to those recovered downstream of 0.2.0.22 micron rated filters (described in Part II) . All of the isolates identified via FAME analyses were common environmental or ubiquitous organisms, and some, such as Acidovorax sp . and Hydrogenophaga pseudoflava, have also been isolated from pharmaceutical water systems . In contrast, four different 0.1 micron rated "sterilizing grade" filter types from two different manufacturers, which had been qualified with both B . diminuta and A . laidlawii, consistently produced sterile effluents under similar test conditions . This study thus highlights the need for an industry or regulatory standard method of defining the microbial removal performance of 0.1 micron rated filters, and supports the use of functionally qualified 0.1 micron rated filters as sterilizing grade filters in pharmaceutical operations for enhanced sterility assurance. Eur J Med Res, 2001 Apr 20, 6(4), 161 - 8 Paradigm change in 30 years peritonitis treatment -- a review on source control; Holzheimer RG et al.; Peritonitis remains a hot spot for surgeons despite advancements in surgical technique and intensive care treatment . There is an ongoing interest to improve the survival rate by analyzing the pathogenesis and pathophysiology of this threatening disease . - The significance of source control, e.g., eradication of a focus of infection, elimination of microbial contamination and restoration of local environment, is well recognized since the beginning of the last century . Recently the term "source control" has gained new interest with regard to guidelines for clinical studies . It appears that despite stratification in most clinical peritonitis studies there is still a lack of comparability of those studies with regard to source control . A medline search on peritonitis and source control was performed and 90 studies were evaluated for information on source control evaluation . In summary, there is no uniform definition of source control available . Most studies in peritonitis treatment are according to evidence based medicine level 3-5 evidence . Lack of hard scientific evidence how to measure the success of source control had to be substituted by surgical experience . Re-operation or relaparotomy may be considered as acknowledgment that source control failed . Controversy exists about primary anastomosis in the inflammed peritoneum . Despite all efforts and more patients enrolled in studies to improve surgical treatment of peritonitis in thirty years it is obvious that the mortality rate has decreased only marginally from 40% to 30% . Commonly accepted principles for source control documentation and evaluation should be established and confirmed in multi-center studies before further studies with new compounds are started. Scand J Immunol, 2001 May, 53(5), 520 - 7 Connectivity patterns in tuberculosis and leprosy patients are indistinguishable from that of healthy donors; Tovar-Rivera T et al.; Connectivity, the self-defined interactions between antigen-recognising molecules in a network system can in part be assessed by measuring the reactivity of a given serum against an ordered set of immunoglobulin (Ig)G F(ab')2 fractions, separated by means of isoelectric focusing so that, the serum reactivity against the whole set of fractions defines a characteristic pattern of connectivity . Deviations from the normal condition (healthy donors) have so far been documented for two autoimmune diseases: systemic lupus erythematosus (SLE) and pemphigus vulgaris, as well as for human immunodeficiency virus (HIV)-1 infection . We tested here if bacterial infections lead to alterations in connectivity . In addition, we wanted to test if two antigenically related bacteria would produce similar or otherwise distinctive connectivity patterns . Connectivity analysis was applied on the sera from tuberculosis and leprosy patients and the sera from healthy donors were used as control . No statistically significant differences between the three groups studied were found . These results have implications for theories that set the origin of autoimmune diseases in microbial infections . To the best of our knowledge, this is the first attempt to analyze the connectivity status in bacterial infections. J Appl Microbiol, 2001 Apr, 90(4), 588 - 99 Development and use of a new medium to detect yeasts of the genera Dekkera/Brettanomyces; Rodrigues N et al.; AIMS: The objectives of this work were to develop a selective and/or differential medium able to efficiently recover Dekkera/Brettanomyces sp . from wine-related environments and to determine the relationship between these yeasts and the 4-ethylphenol content in a wide range of wines . METHODS AND RESULTS: The selectivity of the developed medium was provided by the addition of ethanol, as single carbon source, and cycloheximide . The inclusion of bromocresol green evidenced acid-producing strains . The inclusion of p-coumaric acid, substrate for the production of 4-ethylphenol, enabled the differentiation by smell of Dekkera/Brettanomyces sp . from all other yeast species growing in the medium . The medium was used either by plating after membrane filtration or by the Most Probable Number (MPN) technique . In 29 white and 88 red randomly collected wines, these yeasts were found only in red wines at levels up to 2500 MPN ml-1, but constituted less than 1% of the total microbial flora . In red wines, 84% showed detectable amounts of 4-ethylphenol up to 4430 microg l-1 while 28% of the white wines showed detectable levels up to 403 microg l-1 . CONCLUSION: The use of the medium proposed in this work evidenced the presence of low relative populations of Dekkera/Brettanomyces sp . even in wines contaminated by fast-growing yeasts and moulds . SIGNIFICANCE AND IMPACT OF THE STUDY: Further ecological studies on Dekkera/Brettanomyces sp . should take into account the use of highly specific culture media in order to establish their true occurrence in nature. J Biol Chem, 2001 Jun 29, 276(26), 23777 - 84 Epub 2001 Apr 16. Contribution of the bacterial endosymbiont to the biosynthesis of pyrimidine nucleotides in the deep-sea tube worm Riftia pachyptila; Minic Z et al.; The deep-sea tube worm Riftia pachyptila (Vestimentifera) from hydrothermal vents lives in an intimate symbiosis with a sulfur-oxidizing bacterium . That involves specific interactions and obligatory metabolic exchanges between the two organisms . In this work, we analyzed the contribution of the two partners to the biosynthesis of pyrimidine nucleotides through both the "de novo" and "salvage" pathways . The first three enzymes of the de novo pathway, carbamyl-phosphate synthetase, aspartate transcarbamylase, and dihydroorotase, were present only in the trophosome, the symbiont-containing tissue . The study of these enzymes in terms of their catalytic and regulatory properties in both the trophosome and the isolated symbiotic bacteria provided a clear indication of the microbial origin of these enzymes . In contrast, the succeeding enzymes of this de novo pathway, dihydroorotate dehydrogenase and orotate phosphoribosyltransferase, were present in all body parts of the worm . This finding indicates that the animal is fully dependent on the symbiont for the de novo biosynthesis of pyrimidines . In addition, it suggests that the synthesis of pyrimidines in other tissues is possible from the intermediary metabolites provided by the trophosomal tissue and from nucleic acid degradation products since the enzymes of the salvage pathway appear to be present in all tissues of the worm . Analysis of these salvage pathway enzymes in the trophosome strongly suggested that these enzymes belong to the worm . In accordance with this conclusion, none of these enzyme activities was found in the isolated bacteria . The enzymes involved in the production of the precursors of carbamyl phosphate and nitrogen assimilation, glutamine synthetase and nitrate reductase, were also investigated, and it appears that these two enzymes are present in the bacteria. Scand J Gastroenterol, 2001 Mar, 36(3), 332 - 6 Lymph folliculitis in ulcerative colitis; Chiba M et al.; Preferential involvement of the appendix has recently been confirmed in ulcerative colitis . Since the appendix is an aggregate of lymph follicles, this new observation implies a critical role of the lymph follicles, of both the large bowel and the appendix, in an etiopathogenesis of ulcerative colitis . This report presents two cases of ulcerative colitis in which lymph folliculitis and lymphoid hyperplasia were observed . Lymph folliculitis was observed endoscopically in a border between an established lesion and an uninvolved area . Case 1, proctitis type, relapsing remitting, mild in severity, showed lymph folliculitis in a proximal border of an established rectal lesion . Case 2, with left-sided colitis, mild in severity, had a skip appendiceal orifice inflammation . Lymph folliculitis was observed in the cecum surrounding established appendiceal orifice inflammation . In both cases, lymphoid hyperplasia was observed in an uninvolved area with clear vascular patterns . These two cases clearly demonstrate the involvement of gut lymph follicles in ulcerative colitis . Lymph folliculitis and/or lymphoid hyperplasia was proposed to be early lesions in ulcerative colitis . In addition, the need for microbiology targeting lymph follicles of the large bowel and appendix is stressed in order to disclose the casual microbial agents in ulcerative colitis. Protein Sci, 2000 Nov, 9(11), 2285 - 91 Prediction of a common beta-propeller catalytic domain for fructosyltransferases of different origin and substrate specificity; Pons T et al.; The three-dimensional (3D) structure of fructan biosynthetic enzymes is still unknown . Here, we have explored folding similarities between reported microbial and plant enzymes that catalyze transfructosylation reactions . A sequence-structure compatibility search using TOPITS, SDP, 3D-PSSM, and SAM-T98 programs identified a beta-propeller fold with scores above the confidence threshold that indicate a structurally conserved catalytic domain in fructosyltransferases (FTFs) of diverse origin and substrate specificity . The predicted fold appeared related to that of neuraminidase and sialidase, of glycoside hydrolase families 33 and 34, respectively . The most reliable structural model was obtained using the crystal structure of neuraminidase (Protein Data Bank file: 5nn9) as template, and it is consistent with the location of previously identified functional residues of bacterial levansucrases (Batista et al., 1999; Song & Jacques, 1999) . The sequence-sequence analysis presented here reinforces the recent inclusion of fungal and plant FTFs into glycoside hydrolase family 32, and suggests a modified sequence pattern H-x (2)-{PTV}-x (4)-{LIVMA}-{NSCAYG}-{DE}-P-{NDSC}{GA}3 for this family. J Orofac Orthop, 2001 Mar, 62(2), 146 - 56 Effects of orthodontic bands on marginal periodontal tissues . A histologic study on two human specimens; Diedrich P et al.; Eight banded teeth on two human specimens (9 years, male; 19 years, female) were analyzed regarding the fit of the orthodontic bands and periodontal reactions . Five teeth (three molars, two premolars) were evaluated histologically in the horizontal plane and three (one molar, two premolars) in the sagittal plane using the micro-section method according to Donath . The fit of the bands varied in occluso-apical direction . The mean of marginal gaps was x = 0.23 mm in the occlusal, x = 0.03 mm in the equatorial, and x = 0.28 mm in the cervical area . In the equatorial area the thin cement layer was largely homogeneous, whereas porosities and microfissures were found predominantly in thicker cement layers . 85% of the occlusal and cervical band margins revealed cement defects and/or erosions which were colonized by felted, partially densely compacted microbial plaque . With regard to the periodontal effects, the signs of inflammation in the buccolingual gingival areas were markedly less severe due to the supramarginal position of the band margins . The interdental gingiva of all teeth presented the histological pattern of an established gingival lesion . Leukocyte infiltration and inflammatory exudation in the area of the transseptal fibers were exceptionally pronounced in one lower molar (band exposure time: 6 months) . At this site the connective tissue attachment close to the cementoenamel junction was severely damaged on the mesial surface and the pocket epithelium proliferated towards the apex, meaning progression from established gingivitis to an initial periodontal lesion . The histologic findings on these human periodontal tissues confirm that the application and hygiene control of orthodontic bands have to be performed with great care to avoid permanent periodontal destruction. J Exp Med, 2001 Apr 16, 193(8), 935 - 42 Identification of a chlamydial protease-like activity factor responsible for the degradation of host transcription factors; Zhong G et al.; Microbial pathogens have been selected for the capacity to evade or manipulate host responses in order to survive after infection . Chlamydia, an obligate intracellular pathogen and the causative agent for many human diseases, can escape T lymphocyte immune recognition by degrading host transcription factors required for major histocompatibility complex (MHC) antigen expression . We have now identified a chlamydial protease- or proteasome-like activity factor (CPAF) that is secreted into the host cell cytosol and that is both necessary and sufficient for the degradation of host transcription factors RFX5 and upstream stimulation factor 1 (USF-1) . The CPAF gene is highly conserved among chlamydial strains, but has no significant overall homology with other known genes . Thus, CPAF represents a unique secreted protein produced by an obligate intracellular bacterial pathogen to interfere with effective host adaptive immunity. Eur J Nucl Med, 2001 Feb, 28(2), 241 - 52 Imaging infection/inflammation in the new millennium; Rennen HJ et al.; In the closing half of the past century a wide variety of approaches were developed to visualise infection and inflammation by gamma scintigraphy . Use of autologous leucocytes, labelled with indium-111 or technetium-99m, is still considered the "gold standard" nuclear medicine technique for the imaging of infection and inflammation . However, the range of radiopharmaceuticals used to investigate infectious and non-microbial inflammatory disorders is expanding rapidly . Developments in protein/peptide chemistry and in radiochemistry should lead to agents with very high specific activities . Recently, positron emission tomography with fluorine-18 fluorodeoxyglucose has been shown to delineate infectious and inflammatory foci with high sensitivity . The third millennium will witness a gradual shift from basic (non-specific) or cumbersome, even hazardous techniques (radiolabelled leucocytes) to more sophisticated approaches . Here a survey is presented of the different approaches in use or under investigation. Tree Physiol, 2001 Feb, 21(2-3), 153 - 62 Fate of nitrogen released from 15N-labeled litter in European beech forests; Zeller B et al.; The decomposition and fate of 15N-labeled beech litter was monitored in three European beech (Fagus sylvatica L.) forests (Aubure, France; Ebrach, Germany; and Collelongo, Italy) for 3 years . Circular plots around single beech trees were isolated from roots of neighboring trees by soil trenching, and annual litterfall was replaced by 15N-labeled litter . Nitrogen was continuously released from the decomposing litter . However, over a 2-year period, this release was balanced by the incorporation of exogenous N . Released N accumulated mainly at the soil surface and in the topsoil . Microbial biomass remained almost constant during the experiment at all sites except for considerably lower values at Ebrach . The 15N enrichment of the microbial biomass increased strongly during the first year and then remained stable . The 15N released from the decomposing litter was rapidly detected in roots and leaves of the beech trees, increasing regularly and linearly over the course of the experiment . The uptake of litter-released 15N by the trees was reduced under conditions that reduced tree growth . Under these conditions, leaves and fine roots were the dominant N sinks, and little N was allocated to other plant parts . By contrast, N uptake and N allocation from leaves to stem and bark tissues increased when tree growth was enhanced . Budgets for 15N showed that 2 to 4% of litter-released N was incorporated into the trees, about 35% remained in the litter and about 50% reached the topsoil. Tree Physiol, 2001 Feb, 21(2-3), 145 - 52 Seasonal dynamics of soil carbon dioxide efflux and simulated rhizosphere respiration in a beech forest; Epron D et al.; Respiration of the rhizosphere in a beech (Fagus sylvatica L.) forest was calculated by subtracting microbial respiration associated with organic matter decomposition from daily mean soil CO2 efflux . We used a semi-mechanistic soil organic matter model to simulate microbial respiration, which was validated against "no roots" data from trenched subplots . Rhizosphere respiration exhibited pronounced seasonal variation from 0.2 g C m(-2) day(-1) in January to 2.3 g C m(-2) day(-1) in July . Rhizosphere respiration accounted for 30 to 60% of total soil CO2 efflux, with an annual mean of 52% . The high Q10 (3.9) for in situ rhizosphere respiration was ascribed to the confounding effects of temperature and changes in root biomass and root and shoot activities . When data were normalized to the same soil temperature based on a physiologically relevant Q10 value of 2.2, the lowest values of temperature-normalized rhizosphere respiration were observed from January to March, whereas the highest value was observed in early July when fine root growth is thought to be maximal. Mikrobiol Z, 2000 Jan-Feb, 62(1), 11 - 9 {Hydrodynamic properties of exopolysaccharide-acrylamide copolymer}; Votselko SK; The method for producing copolymer EPAA of exopolysaccharide (EPS)--polyacrylamide (PAA) has been presented which was based on microbial exopolysaccharides (enposane, xampane), their mixture and model EPS (xanthane sigma, rodopol P-23) . The copolymer was produced by acrylamide polymerization in 1-2% water solutions of polysaccharides, the concentration of acrylamide in the reaction mixture being 4.7-2% and that of polysaccharides 0.1-1% of the weight . Hydrodynamic parameters of the studied polymers have been determined, their heterogenity as to molecular-weight characteristics has been demonstrated . Molecular-weight distribution of copolymers showed that the content of low-molecular fractions decreased, thus the Mw values were (0.08-0.2) x 10(6) Da in contrast to that of exopolysaccharides possessing Mw (1.2-0.4) x 10(6) Da and of polyacrylamide possessing Mw within (2-30) x 10(6) Da . The value of efficient viscosity of copolymers ranged from 120 to 131 mPa.s that was lower than that of polyacrylamide (500 mPa.s), and higher than that of exopolysaccharides (42 mPa.s), and it depended on the sample, raw material, production conditions . A possibility has been shown to produce a new copolymer based on microbial polysaccharides enposane and xampane in the process of acrylamide polymerization . It has been found out that the studied copolymers EPAA differ from initial ones as to their hydrodynamical properties, which determines their preference: better solubility, good glueing properties, prolonged term of preservation, resistance to bacterial pollution. Lett Appl Microbiol, 2001 Apr, 32(4), 278 - 81 Inhibitory effect of acetosyringone on two aflatoxin biosynthetic genes; Hua SS; AIMS: The objective of this study was to determine if acetosyringone affected the expression of aflatoxin biosynthetic genes . METHODS AND RESULTS: Two genes, nor1 and ver1, representing genes whose products are involved in early and late steps in aflatoxin biosynthesis, were examined . Two GUS (beta-glucuronidase) reporter constructs, nor1:GUS (pGAP12) and ver1:GUS (pGAP13), were used to study the effect of acetosyringone on expression of aflatoxin biosynthetic (AF) genes, nor1 and ver1 . The product of nor1 is involved in the formation of norsolorinic acid, the first stable intermediate in the aflatoxin pathway . The ver1 gene codes for the enzyme catalyzing the formation of demethylsterigmatocystin, an intermediate late in the AF pathway . GUS activities of these two reporter constructs were inhibited by 80% in the presence of 2 m mol l-1 acetosyringone . CONCLUSION: Aflatoxin production in a toxigenic strain 4