Microorganism

Cell Mol Life Sci, 2000 Apr, 57(4), 542 - 51
Molecular mimicry: a critical look at exemplary instances in human diseases; Rose NR et al.; Molecular mimicry, the concept that antigenic determinants of microorganisms resemble antigenic determinants of the host, is frequently cited as a plausible mechanism to account for the association of infection and autoimmune disease . Based on analogous sequences of amino acids or on cross-reactions of monoclonal antibodies, numerous examples of such mimicry have been reported . There are, however, no clear examples of a human disease caused by molecular mimicry.

Acta Obstet Gynecol Scand, 2000 Dec, 79(12), 1069 - 74
A case-referent study on fetal bacteremia and late fetal death of unknown etiology in Lithuania; Maleckiene L et al.; BACKGROUND: The objectives were to test the hypothesis that certain strains of microorganisms are present in fetal blood in a significant proportion of parturient women suffering unexplained third trimester fetal death, and to examine the correlation between fetal bacteremia and histologic chorioamnionitis and vasculitis . METHODS: A case-referent study was carried out on 58 pregnant women with fetal death of unknown etiology (cases) and 116 pregnant women at term (referents) with live fetuses . Cultures from maternal endocervix, amniotic fluid, placental homogenate, external ear and blood of newborns were performed in both groups . Histological examination of placentas and fetal membranes was carried out in order to identify chorioamnionitis and chorionic vasculitis . RESULTS: Intrauterine fetal bacteremia was observed in 36% of cases and in 0% of referents (p= 0.001) . Escherichia coli was the most common strain, isolated in 21% of fetal blood samples in cases . Extensive histologic chorioamnionitis was observed in 50% of cases with the presence of Escherichia coli in blood of stillborns . Chorionic vasculitis was found in 67% of such cases . Positive significant correlations between isolation of the Escherichia coli from maternal endocervix, amniotic fluid, placenta, fetal ear and blood in stillborns and histological chorioamnionitis and chorionic vasculitis were observed . CONCLUSIONS: Escherichia coli bacteremia was detected in a significant proportion of stillborns suffering a third trimester prelabor death . Fetal bacteremia significantly correlated with histologic signs of inflammation in placenta and membranes . Ascending subclinical intrauterine infection may play an important role in the etiology of otherwise unexplained late prelabor fetal death.

J Biol Chem, 2001 Apr 6, 276(14), 11113 - 25 Epub 2000 Dec 14.
Transepithelially transported pro-phenoloxidase in the cuticle of the silkworm, Bombyx mori . Identification of its methionyl residues oxidized to methionine sulfoxides; Asano T et al.; Pro-phenoloxidase (proPO) in insects is activated through the action of a protease cascade triggered by minute amounts of microbial cell wall components . It is an important molecule for the defense against invading microorganisms and for the repair of wounds . In the accompanying paper (Asano, T., and Ashida, M . (2001) J . Biol . Chem . 276, 11100-11112), a proPO isoform, proPO-HS, in the hemolymph of the silkworm, Bombyx mori, is reported to be transported to the cuticle . The transported proPO isoform was recovered from the cuticle and named proPO-CS . The elution profiles of proPO-CS and proPO-HS in reversed-phase high performance liquid chromatography (HPLC) were found to be different, giving a basis to the inference that proPO-CS is a modified form of proPO-HS . In the present study, we investigated the nature of the modifications occurring in proPO-CS, in which proteolytically and chemically cleaved fragments originating from the subunits of proPO-CS and proPO-HS were analyzed by reversed-phase HPLC, amino acid sequencing, and mass spectrometry . A subunit of the heterodimeric proPO-CS was found to contain five or six methionine sulfoxides, and another subunit was found to contain one methionine residue oxidized to the sulfoxide . All of the oxidized methionyl residues were identified . Other than oxidation of the methionyl residues, no additional modification of proPO-CS was found . In the model structure of each subunit of proPO-CS constructed by protein modeling with the known structures of the horseshoe crab, Limulus polyphemus, hemocyanin type II subunit as templates, the methionine residues identified as methionine sulfoxide had high degrees of accessibility to the solvent . The implication of the oxidation at the methionine residues is discussed in relation to the mechanism of transepithelial transport of proPO from the hemolymph to the cuticle.

Postgrad Med J, 2001 Jan, 77(903), 16 - 9
The health professional's role in preventing nosocomial infections; Saloojee H et al.; Despite their best intentions, health professionals sometimes act as vectors of disease, disseminating new infections among their unsuspecting clients . Attention to simple preventive strategies may significantly reduce disease transmission rates . Frequent hand washing remains the single most important intervention in infection control . However, identifying mechanisms to ensure compliance by health professionals remains a perplexing problem . Gloves, gowns, and masks have a role in preventing infections, but are often used inappropriately, increasing service costs unnecessarily . While virulent microorganisms can be cultured from stethoscopes and white coats, their role in disease transmission remains undefined . There is greater consensus about sterile insertion techniques for intravascular catheters-a common source of infections-and their care . By following a few simple rules identified in this review, health professionals may prevent much unnecessary medical and financial distress to their patients.

Cytometry, 2001 Jan 1, 43(1), 82 - 5
Quantitative assessment of phagocytic activity of hemocytes in the prawn, Penaeus merguiensis, by flow cytometric analysis; Lee YK et al.; BACKGROUND: The blood cells of crustaceans are involved in phagocytosis of invading microorganisms, contributing to their defense mechanisms . In this study, phagocytic activity of hemocytes of the prawn, Penaeus merguiensis, was quantitated by means of flow cytometric analysis . METHOD: This study was done in vitro . Hemolymph, which was extracted from prawns, was mixed with an equal volume of anticoagulant . Heat-killed Escherichia coli prestained with propidium iodide (PI) was then added . Hemocytes were fixed at various time intervals for flow cytometric analysis . This study was supplemented with electron micrographs using transmission electron microscopy (TEM), which showed three populations of hemocytes . RESULTS: It was observed that those hemocytes that were more active engulfed and digested bacteria readily, thus having higher red fluorescence intensity . The phagocytic activity was expressed as fluorescence unit or engulfed E . coli number per hemocyte . CONCLUSIONS: With this approach, the phagocytic and cellular activity of individual hemocyte populations could be studied quantitatively.

Proc Natl Acad Sci U S A, 2001 Jan 2, 98(1), 60 - 2
An anthelmintic compound, nafuredin, shows selective inhibition of complex I in helminth mitochondria; Omura S et al.; Infections with parasitic helminths are important causes of morbidity and mortality worldwide . New drugs that are parasite specific and minimally toxic to the host are needed to counter these infections effectively . Here we report the finding of a previously unidentified compound, nafuredin, from Aspergillus niger . Nafuredin inhibits NADH-fumarate reductase (complexes I + II) activity, a unique anaerobic electron transport system in helminth mitochondria, at nM order . It competes for the quinone-binding site in complex I and shows high selective toxicity to the helminth enzyme . Moreover, nafuredin exerts anthelmintic activity against Haemonchus contortus in in vivo trials with sheep . Thus, our study indicates that mitochondrial complex I is a promising target for chemotherapy, and nafuredin is a potential lead compound as an anthelmintic isolated from microorganisms.

FEMS Immunol Med Microbiol, 2000 Dec, 29(4), 323 - 8
Immune cell functions, lipids and host natural resistance; de Pablo MA et al.; Nutritional status may exert a profound effect on immune system functions . Hence, several parameters of immune system are modified by dietary lipid administration, as lymphocyte proliferation, cytokine production, natural killer activity, antigen presentation, etc . Thus, numerous studies have indicated the key role of lipids as immune response modulators . These properties have been applied in the treatment of autoimmune and inflammatory diseases . As a result, the reduction or suppression of immune status due to lipid incorporation promotes an impairment in the ability of host natural response to eliminate infectious microorganisms as bacteria or parasites . In the present review, we analyze the current status about the relationship among dietary lipids, reduction of immune parameters and reduction of host natural response against infectious diseases . Many discrepancies are discussed, although several studies indicate a close association between dietary lipid manipulation and impairment in the elimination of bacteria, viruses or parasites . On the other hand, other studies point out a beneficial effect of dietary lipid manipulation on the host natural response . Future investigations will determine the events involved in the regulation of immune response by fatty acids and their role in the elimination of pathogenic agents.

Int J Gynaecol Obstet, 2000 Dec, 71 Suppl 1, S37 - 46
Sertaconazole: pharmacology of a gynecological antifungal agent; Palacin C et al.; Sertaconazole is a broad spectrum antifungal agent with excellent activity against yeasts, dermatophytes and opportunistic fungi . In addition to this antifungal efficacy, it has a good safety profile, sustained cutaneous retention, and low systemic absorption, all of which make it ideal for topical applications . In this study, the pharmacological properties of sertaconazole related to the treatment of vaginal fungi, in particular vulvovaginal candidiasis, are reviewed . As with all other infectious processes, the interacting components are infectious microorganism, host and drug . The following properties of sertaconazole have been investigated in pre-clinical studies: its in vitro spectrum of activity and potency against causative agents and accompanying factors in vaginal infection; its mechanism of action, whether it acts on the pathogenic properties of the microorganism; if it affects host defense mechanisms and how its antifungal activity is manifested in vivo in experimental candidiasis in the mouse.

Biochem Biophys Res Commun, 2000 Dec 20, 279(2), 462 - 7
Amino acid residues conferring herbicide tolerance in tobacco acetolactate synthase; Chong CK et al.; Acetolactate synthase (ALS) is the common enzyme in the biosynthetic pathways leading to valine, leucine, and isoleucine in plants and microorganisms . ALS is the target site of several classes of structurally unrelated herbicides including sulfonylureas, imidazolinones, and triazolopyrimidines . To identify the residues conferring herbicide tolerance in tobacco ALS, site-directed mutagenesis for three residues, Ala121, Pro187 and Ser652, was performed . Mutant A121T showed strong resistance to Londax (a sulfonylurea) and Cadre (an imidazolinone), while mutant S652T was resistant only to Cadre . The S652N mutation abolished the binding affinity of FAD, and inactivated the enzyme . Double mutation of Ala121 and Ser652 with Thr yielded a mutant highly tolerant to Londax, Cadre, and TP (a triazolopyrimidine sulfonamide), but has enzymatic properties similar to those of wild-type . Substitution of Pro187 with Ser resulted in the enzyme highly susceptible to oxidation and fragmentation . These results suggest that two residues Ala121 and Ser652 are potent residues conferring herbicide resistance in tobacco ALS, and that double mutation of Ala121 and Ser652 by Thr can confer stronger tolerance to Londax, Cadre, and TP .

Nature, 2000 Nov 30, 408(6812), 574 - 8
Geochemical evidence for terrestrial ecosystems 2.6 billion years ago; Watanabe Y et al.; Microorganisms have flourished in the oceans since at least 3.8 billion years (3.8 Gyr) ago, but it is not at present clear when they first colonized the land . Organic matter in some Au/U-rich conglomerates and ancient soils of 2.3-2.7 Gyr age has been suggested as remnants of terrestrial organisms . Some 2.7-Gyr-old stromatolites have also been suggested as structures created by terrestrial organisms . However, it has been disputed whether this organic matter is indigenous or exogenic, and whether these stromatolites formed in marine or fresh water . Consequently, the oldest undisputed remnants of terrestrial organisms are currently the 1.2-Gyr-old microfossils from Arizona, USA . Unusually carbonaceous ancient soils--palaeosols--have been found in the Mpumalanga Province (Eastern Transvaal) of South Africa . Here we report the occurrences, elemental ratios (C, H, N, P) and isotopic compositions of this organic matter and its host rocks . These data show that the organic matter very probably represents remnants of microbial mats that developed on the soil surface between 2.6 and 2.7 Gyr ago . This places the development of terrestrial biomass more than 1.4 billion years earlier than previously reported.

Prikl Biokhim Mikrobiol, 2000 Nov-Dec, 36(6), 679 - 84
{Development of biological methods of combating steel corrosion, induced by aerobic microorganisms}; Rodin VB et al.; Cocultivation of degrading microorganisms and their antagonists decreases the corrosion loss of carbon steel by 20 to 80% . It was found that a microorganism can either accelerate or inhibit corrosion, depending on the nutrient . The magnitude of the effect on corrosion depends on the ability of the microorganism to respond to changes in the nutrient-medium composition by releasing acidic or alkaline metabolites.

Prikl Biokhim Mikrobiol, 2000 Nov-Dec, 36(6), 672 - 8
{Microorganisms as possible indicators of soil pollution by dioxin-containing defoliants}; Mitsevich EV et al.; The diversity of microorganisms from soils treated in the past with various dosages of dioxin-containing defoliants was studied . Population alterations dependent on dioxin concentrations were elucidated . Soil fungi and, to a smaller extent, actinomycetes were found to be the most sensitive to dioxins.

Prikl Biokhim Mikrobiol, 2000 Nov-Dec, 36(6), 661 - 5
{Development and testing of "Ekosorb" biosorbent based on association of petroleum-oxidizing bacteria for purifying petroleum-polluted soils}; Chugunov VA et al.; A biosorbent containing an association of oil-oxidizing bacteria as a main constituent was developed, in which Lessorb, a product of moss and wood thermal processing, was used as a carrier . Xeroprotectors preserving the cell viability and oil-oxidizing activity in the biosorbent on drying and after long-term storage were selected . The use of this biosorbent for cleaning oil-polluted sod-podzol soils showed a two-threefold cleanup rate acceleration at different pollution levels (8 and 24 l/m2), especially in the presence of a nitrogen-phosphate fertilizer . The biosorbent increased the populations of certain groups of soil microorganisms and the total soil biological activity.

Prikl Biokhim Mikrobiol, 2000 Nov-Dec, 36(6), 642 - 6
{Microbial degraders of some organochlorine compounds}; Mitsevich EV et al.; A possibility of isolation of microorganisms, potential destructors of chlorinated organics from aged Vietnamese soils polluted with dioxine-containing defoliants was demonstrated . As an example, the ability of one isolated strain to metabolize pentachlorophenol and 2,4-dichlorophenoxyacetic acid was shown under laboratory conditions . An attempt was made to identify intermediates of pentachlorophenol metabolism using HPLC.

Prikl Biokhim Mikrobiol, 2000 Nov-Dec, 36(6), 637 - 41
{Initial stages of steel biocorrosion}; Zhigletsova SK et al.; Initial stages of corrosion of mild steel induced by Klebsiela rhinoscleromatis BO2 were studied in various media . The effect of the microorganism was detected 8-10 h after inoculation . The number of viable cells were virtually unchanged within one month in all media, but the corrosive activity of the strain decreased . The corrosive activity of microorganisms can be determined by spectrophotometry even only after incubation for 24 h . At a low level of organic substrate, even strong colonization with microorganisms does not inevitably result in a significant damage to metals.

Curr Microbiol, 2001 Jan, 42(1), 12 - 7
In vitro catabolism of histidine by mixed rumen bacteria and protozoa; Wadud S et al.; An in vitro study was conducted to examine the metabolism of histidine (His) by mixed rumen bacteria (B), mixed rumen protozoa (P), and a combination of the two (BP) . Rumen microorganisms were collected from fistulated goats fed with lucerne cubes (Medicago sativa) and a concentrate mixture twice a day . Microbial suspensions were anaerobically incubated with or without 2 mm each of His, or histamine (HTM), or 1 mm urocanic acid (URA) at 39 degrees C for 12 h . His and other related compounds in both supernatant and microbial hydrolysates were analyzed by HPLC . After 6- and 12-h incubations, the net degradation of His was 26.1% and 51.7% in B, 13.5% and 20.9% in P, and 21.7% and 46.0% in BP, respectively . The rate of the net degradation of His in B (98.0 micromol/g microbial nitrogen/h) was about 2.6 times higher than that of P during a 12-h incubation period . His was found to be degraded into urocanic acid (URA), imidazolelactic acid (ImLA), imidazoleacetic acid (ImAA), and histamine (HTM) . Of these degraded His was mainly converted into URA in all microbial suspensions . The production of ImLA and ImAA was higher in B than in P suspensions, whereas the production of HTM was higher in P than in B suspensions . From these results, the existence of diverse catabolic routes of His in rumen microorganisms was indicated.

Vaccine, 2000 Nov 22, 19(7-8), 958 - 65
Immunogenicity of a foreign peptide expressed within a capsid protein of an attenuated coxsackievirus; Halim SS et al.; The immunogenicity of soluble peptides can be improved by expression within recombinant microorganisms . The immunogenicity of a peptide expressed within a capsid protein of an attenuated coxsackievirus B4 was evaluated . The insertion site was chosen based on its antigenic structure . A foreign peptide was inserted into a region of the VP1 capsid protein that was identified as a T helper cell epitope . A recombinant virus containing ten amino acids of ovalbumin sequence was genetically stable and retained the biological and physical characteristics of the parental virus . The recombinant was able to elicit a T helper cell response against ovalbumin sequences . This study shows, for the first time, that coxsackievirus can be used as an expression vector and that insertion of heterologous peptides into an immunogenic region is a viable strategy for inducing T helper cell responses against foreign sequences . The implications of this work are that the attenuated coxsackievirus variant may be useful as a vaccine vector for expressing T helper cell epitopes that are important in inducing protective immunity.

Vaccine, 2000 Nov 22, 19(7-8), 862 - 76
A systematic approach to vaccine complexity using an automaton model of the cellular and humoral immune system . I . Viral characteristics and polarized responses; Kohler B et al.; A modern approach to vaccination faces the compound complexity of microorganism behavior and immune response triggering and regulation . Since computational modeling can yield useful guidelines for biological experimentation, we have used IMMSIM(3), a cellular automaton model for simulating humoral- and cell-mediated responses, to explore a wide range of virus-host relations . Sixty-four virtual viruses were generated by an assortment of speed of growth, infectivity level and lethal load . The outcome of the infections, as influenced by the immune response and the bolstering of cures, obtained by vaccine presensitization are illustrated in this first article . The results of the in machina experiments allow us to relate the success rate of responses to certain combinations of viral parameters and by freezing one or the other branch, and to determine that some viruses are more susceptible to humoral, and others to cellular responses, depending either on single parameters or combinations thereof . This finding allows prediction of which infection may be susceptible to polarized ((Th)(1)>Th(2) and Th(1)<Th(2)) responses and will eventually help designing vaccines whose action relies on antagonizing both the specificity and the behavior of the invader . A second, not lesser, result of this study is the finding that humoral and cellular responses, while cooperating, towards the cure of the infected body, also show significant patterns of competition and mutual thwarting.

J Mol Biol, 2001 Jan 5, 305(1), 109 - 20
NMR structure of Streptomyces killer toxin-like protein, SKLP: further evidence for the wide distribution of single-domain betagamma-crystallin superfamily proteins; Ohki SY et al.; A protein isolated from the culture supernatant of the soil bacterium, Streptomyces sp . F-287, exhibits cytocidal effects for both budding and fission yeasts, and causes morphological changes of yeasts and filamentous fungi . This protein, which was the first killer toxin-like protein for yeasts identified in the Streptomyces microorganism, was named SKLP (Streptomyces killer toxin-like protein) . Since the amino acid sequence of the protein, as determined by sequential Edman degradations, seemed to be unique, we determined the structure by NMR spectroscopy . Although the actual target of SKLP in yeasts has not been determined yet, the structure might give us a clue to characterize the targets . The solution structure of SKLP determined by NMR, however, turned out to be a single-domain crystallin-like protein, with two Greek key motifs and a short extra beta-strand at the N terminus . The final ensemble of 20 NMR structures overlaid onto their mean coordinate with rmsd values of 0.32(+/-0.06) A for the backbone atoms involved in the secondary structure elements . As a yeast killer toxin, WmKT, isolated from the yeast strain Williopsis mrakii also has a Greek key beta-barrel fold, we have made a detailed comparison of the structural features of SKLP with the other crystallin superfamily proteins . It is very interesting that SKLP has a unique electrostatic potential distribution on the molecular surface . Namely, one surface of the beta-barrel fold in SKLP has a large negatively charged region, with an isolated positive charge of the Arg62 side-chain at the center . The edge of this surface is surrounded by positively charged residues, including Arg31, Arg65 and Arg74 . The salient features of the charge distribution on this surface and the cluster of Arg residues might be related to the target binding of SKLP .

Rapid Commun Mass Spectrom, 2000, 14(24), 2362 - 6
Identification of an N-(hydroxysulfonyl)oxy metabolite using in vitro microorganism screening, high-resolution and tandem electrospray ionization mass spectrometry; Pilard S et al.; Preliminary metabolic profiling of a drug under pre-clinical development revealed the presence of a minor unknown metabolite with a positive ion electrospray ionization (ESI) mass spectrum identical to that of the unchanged compound . Since the low concentration of the compound did not allow any additional experiments, preparative bioconversion using fungi was used to obtain a substantial amount of the molecule . Negative ion ESI-MS and tandem mass spectrometry (MS/MS) in combination with accurate mass measurements obtained on a quadrupole/time-of-flight instrument (Q-TOF) led to the positive identification of a hydroxylamide sulfoconjugated metabolite .

Biochim Biophys Acta, 2000 Dec 15, 1524(2-3), 189 - 95
Demonstration of the central dark line in crystals of dental calculus; Kakei M et al.; Using an electron microscope and Fourier transform infrared (FTIR) microspectroscopy, we studied the lattice images of crystallites of dental calculus to demonstrate the presence of the central dark line (CDL) in its crystallite and to compare this CDL with that of bone and synthetic hydroxyapatite crystals . Ultrastructural observations revealed clearly a number of crystallites, which displayed a proper lattice image and CDL similar to that of bone, in the dental calculus . FTIR microspectroscopy revealed that the dental calculus displayed a set of major spectra analogous to that of bone . These results suggest that the formation process of hydroxyapatite crystals with CDL in dental calculus, which is considered to be an unusual type of calcified structure in association with microorganisms, is basically similar to that of the ordinary calcifying hard tissues (bone, enamel, etc.).

FEMS Microbiol Lett, 2000 Dec 15, 193(2), 237 - 41
Enzymatic versus spontaneous S-methyl thioester synthesis in Geotrichum candidum; Helinck S et al.; The synthesis of short chain S-methyl thioesters was investigated in Geotrichum candidum strain GcG . The results indicated the involvement of an enzymatic reaction in this microorganism that led to the synthesis of S-methyl thioacetate (MTA) when methanethiol and acetyl-CoA were used as substrates . MTA was generated from these substrates by enzymatic or spontaneous reactions, whose relative importance depended largely on pH and temperature . For longer chain acyl-CoA compounds (C3 to C6), thioester synthesis was primarily spontaneous . Short chain fatty acid activation by a CoA residue probably is a prerequisite for the synthesis of S-methyl thioesters.

Radiology, 2000 Dec, 217(3), 647 - 56
Pulmonary infections in immunocompromised hosts: the importance of correlating the conventional radiologic appearance with the clinical setting; Oh YW et al.; The lung is one of the most frequently involved organs in a variety of complications in the immunocompromised host . Among the pulmonary complications that occur in this kind of patient, infection is the most common and is associated with high morbidity and mortality . Although chest radiography and computed tomography (CT) are essential diagnostic tools, radiologists often have difficulty in establishing the correct diagnosis on the basis of radiologic findings alone . The reasons are that the immunocompromised host is potentially susceptible to infection from many different microorganisms and that radiologic findings are seldom specific for the detection of a particular pathogen . Experience has shown that a particular clinical setting predisposes patients to infection by particular pathogens . The setting comprises (a) the specific epidemiologic or environmental exposure, (b) the type of underlying immune defect, (c) the duration and severity of immune compromise, and (d) the progression rate and pattern of the radiologic abnormality . Correlating the radiologic appearance with the clinical setting can expedite diagnosis and appropriate therapy . In this review, the authors describe the clinical settings that are helpful in choosing the radiologic approach to treatment of the immunocompromised host who presents with suspected pulmonary infection.

Int Microbiol, 2000 Mar, 3(1), 9 - 16
Molecular phylogeny: pitfalls and progress; Moreira D et al.; Molecular phylogeny based on nucleotide or amino acid sequence comparison has become a widespread tool for general taxonomy and evolutionary analyses . It seems the only means to establish a natural classification of microorganisms, since their phenotypic traits are not always consistent with genealogy . After an optimistic period during which comprehensive microbial evolutionary pictures appeared, the discovery of several pitfalls affecting molecular phylogenetic reconstruction challenged the general validity of this approach . In addition to biological factors, such as horizontal gene transfer, some methodological problems may produce misleading phylogenies . They are essentially (i) loss of phylogenetic signal by the accumulation of overlapping mutations, (ii) incongruity between the real evolutionary process and the assumed models of sequence evolution, and (iii) differences of evolutionary rates among species or among positions within a sequence . Here, we discuss these problems and some strategies proposed to overcome their effects.

Int Microbiol, 1999 Dec, 2(4), 207 - 16
Not plants or animals: a brief history of the origin of Kingdoms Protozoa, Protista and Protoctista; Scamardella JM; In the wake of Darwin's evolutionary ideas, mid-nineteenth century naturalists realized the shortcomings of the long established two-kingdom system of organismal classification . Placement in a natural scheme of Protozoa, Protophyta, Phytozoa and Bacteria, microorganisms that exhibited plant-like and animal-like characteristics but obviously differed in organization from larger plants and animals, challenged traditional classification . The attempts of naturalists to classify these organisms outside the constraints of the plant and animal kingdoms led to concepts of additional kingdoms (Protozoa, Protista, Protoctista, etc.) to accommodate the nature of these organisms as not true plants or animals.

Int Microbiol, 1999 Sep, 2(3), 145 - 54
Intracellular parasitism and molecular determinants of Legionella virulence; Belyi Y; Bacteria of the genus Legionella are intracellular parasites and major human pathogens . They bind to surface receptors, penetrate eukaryotic cells and initiate complex disorders during phagocytosis . These disorders include inhibition of oxidative burst, a decrease in phagosome acidification, the blocking of phagosome maturation and changes in organelle trafficking . As a result, the microorganisms prevent the bactericidal activity of the phagocyte and transform the phagosome into a niche for their replication . Biological, biochemical and molecular-genetic approaches have been used to identify a panel of bacterial products that may be involved in Legionella virulence . They include cytotoxins, several enzymes and a set of genes thought to encode proteins of the export machinery . However, despite distinct progress in research, the molecular mechanisms underlying intracellular parasitism in Legionella are unclear.

Int Microbiol, 1998 Dec, 1(4), 295 - 300
Selection of very small differences in bacterial evolution; Baquero F et al.; As the Science of Biology is constantly changing due to new discoveries and advanced techniques it is essential that a systematic study of the environmental causes of natural selection on microorganisms be conducted . Very small phenotypic differences among individuals within bacterial populations arise as a result of spontaneous genetic variation, but the evolutionary importance of these small changes is frequently considered to be non-significant . Recent in vitro experiments indicate that efficient selection of these very small differences may take place in environmental compartments where a particular intensity of the selective agent is exerted . Model studies based on competition between bacterial populations only differing in one or two amino acid changes of a detoxifying antibiotic enzyme (e.g . beta-lactamase) have shown that at a narrow range of antibiotic concentrations the variant population is strongly selected over the original type, despite the extremely low phenotypic differences in antibiotic susceptibility . These selective concentrations are expected to occur in precise environmental compartments (selective compartments) . Due to the high frequency of structured habitats in natural environments, the intensity of selective agents is commonly exerted along certain gradients . Each one of the points forming these gradients (or intersection among gradients) may have a particular selective ability for a specific genetic variant . Considering the environment as a composition of an extremely high number of specific selective compartments may help to understand the existence of high levels of genetic variability in natural bacterial populations . This may be one of the clues towards the unraveling of bacterial evolution.

Int Microbiol, 1998 Dec, 1(4), 285 - 94
Crucial crises in biology: life in the deep biosphere; Guerrero R; The origin and evolution of life on Earth are the result of a series of crises that have taken place on the planet over about 4500 millions of years since it originated . Biopoiesis (origin of life), ecopoiesis (origin of ecosystems) and the first ecosystems (stromatolites and microbial mats), as well as eukaryopoiesis (origin of nucleated cells) are revised . The paper then focuses on the study of the deep biosphere, describing ecosystems never found before, which are independent of solar radiation and have changed previous assumptions about the requirements of life; even the concept of biosphere, as Vernadsky defined it, has increased its scope . Since the discovery, in 1987, of bacteria growing in the crevices of rocks at 500 m deep, in boreholes drilled near the Savanna River, Aiken, South Carolina, other bacteria have been found in the deep subsurface reaching depths of about 3 km (e.g., in the Columbia River Basalt Group, near Richland, Washington state), in an anaerobic, hot, high-pressure environment . Some kinds of microorganisms can thrive at such depths, living in many cases a geochemical existence, by using very specialized metabolisms, which depend on the local environments . The existence of organisms independent from photosynthetic production is the most outstanding, novel feature of the deep biosphere . Living beings might not need other energy and chemical sources than those which occur in the development of all planetary bodies . Life, therefore, could even be an ineluctable outcome of planetary evolution and, as a corollary, a natural continuation of the usual development of physical phenomena in the universe.

J, Exp . Mar . Biol . Ecol. . 2000 Dec 20, 255(2), 201 - 214
Diurnal changes in pore water sulfide concentrations in the seagrass Thalassia testudinum beds: the effects of seagrasses on sulfide dynamics; Lee K et al.; The dynamics of the seagrass-sulfide interaction were examined in relation to diel changes in sediment pore water sulfide concentrations in Thalassia testudinum beds and adjacent bare areas in Corpus Christi Bay and lower Laguna Madre, Texas, USA, during July 1996 . Pore water sulfide concentrations in seagrass beds were significantly higher than in adjacent bare areas and showed strong diurnal variations; levels significantly decreased during mid-day at shallow sediment depths (0-10 cm) containing high below-ground tissue biomass and surface area . In contrast, diurnal variations in sediment sulfide concentrations were absent in adjacent bare patches, and at deeper (>10 cm) sediment depths characterized by low below-ground plant biomass or when the grasses were experimentally shaded . These observations suggest that the mid-day depressions in sulfide levels are linked to the transport of photosynthetically produced oxygen to seagrass below-ground tissues that fuels sediment sulfide oxidation . Lower sulfide concentrations in bare areas are likely a result of low sulfate reduction rates due to low organic matter available for remineralization . Further, high reoxidation rates due to rapid exchange between anoxic pore water and oxic overlying water are probably stimulated in bare areas by higher current velocity on the sediment surface than in seagrass beds . The dynamics of pore water sulfides in seagrass beds suggest no toxic sulfide intrusion into below-ground tissues during photosynthetic periods and demonstrate that the sediment chemical environment is considerably modified by seagrasses . The reduced sediment sulfide levels in seagrass beds during photosynthetic periods will enhance seagrass production through reduced sulfide toxicity to seagrasses and sediment microorganisms related to the nutrient cycling.

J Vet Diagn Invest, 2000 Nov, 12(6), 552 - 7
Pathogenesis of liver lesions caused by experimental infection with Piscirickettsia salmonis in juvenile Atlantic salmon, Salmo salar L; Almendras FE et al.; Piscirickettsia salmonis, the etiologic agent of salmonid rickettsial septicemia (SRS), or piscirickettsiosis, causes substantial economic losses to the salmon industry . The pathogenesis of the disease has not been fully characterized . The aim of this study is to describe the hepatic lesions associated with experimental P . salmonis infection in Atlantic salmon juveniles . Fish were maintained in fresh water and inoculated intraperitoneally (IP), orally, or on the gill surface with P . salmonis . A group of uninfected fish was kept as control . Liver samples from 5 fish in each inoculated group and 3 controls were collected weekly and processed for histological and immunohistochemical examination . Thickening of the liver capsule by inflammatory cells was a characteristic histologic feature of IP inoculated fish . Three weeks post-IP inoculation, 8 fish had died and 2 fish were sampled . Histological changes at this time consisted of vasculitis, presence of fibrin thrombi, vacuolated hepatocytes and focal areas of necrosis . Leukocytes containing intracytoplasmic basophilic microorganisms were seen within hepatic sinusoids . Vasculitis and intracytoplasmic vacuoles were prominent features in fish inoculated orally and on the gill surface . The presence of P . salmonis within hepatocellular vacuoles, endothelial cells, and leucocytes was confirmed by immunohistochemistry . The intracellular location of P . salmonis and the vascular damage seen in infected fish are characteristic of rickettsial infections . Histological lesions induced by experimental infection with P . salmonis using the oral and gill surface routes were similar to those observed in natural outbreaks of piscirickettsiosis . The tropism of P . salmonis for endothelial cells explains the vascular lesions observed in SRS, whereas hepatic lesions are due to ischemic necrosis and direct injury by intracytoplasmic organisms.

Angiology, 2000 Oct, 51(10), 827 - 30
Identificaiton of chlamydia penumoniae DNA in caroitd plaques; Chierichetti F et al.; Chlamydia pneumoniae (CP) is a bacterium that in recent years has been investigated as an etiologic agent for atherosclerosis . It is a ubiquitous microorganism that has been isolated in various regions of the vascular system and its prevalence is about 10% in the patient population . This study involved a group of 43 patients (27 men, 16 women, mean age 68 years) who underwent carotid endarterectomy . About 9.3% of the patients yielded plaques that tested positive for the DNA genome of Chlamydia pneumoniae.

Med Dosw Mikrobiol, 2000, 52(2), 165 - 71
{Bactericidal properties of neutrophils from peripheral blood (PMN)of patients with Lyme borreliosis}; Izycka A et al.; In recent years in Poland, the interest has increased in studies about tick borne diseases, mainly Lyme borreliosis . Immune response and genotype of pathogen play an important role in the course of this disease . Phagocytic cells, especially PMN are dominant in defence mechanisms against bacterial infections . The main feature of PMN is their ability to destroy pathogenic microorganisms by phagocytosis . The aim of this study was to estimate the phagocytic activity of PMN connected with intracellular respiratory burst in patients with Lyme borreliosis . The PMN activity tests completed were: phagocytosis, spontaneous and reduced of nitrotetralizate blue test (NBT) . Decreased phagocytic activity and oxygen metabolism of PMN from patients with borreliosis in comparison with values of controls were found . Normalization of these parameters after treatment was observed . Changed phagocytic activity connected with intracellular oxygen metabolism during the course of therapy was the main observation . Depression of phagocytic activity of PMN connected with oxygen metabolism can influence defence reactions in patients with Lyme borreliosis . It is suggested that changes observed are acquired and associated with Borrelia burgdorferi presence.

Biochim Biophys Acta, 2000 Nov 20, 1460(2-3), 276 - 90
An elementary kinetic model of energy coupling in biological membranes; Cristina E et al.; The purpose of this work is to contribute to the understanding of the fundamental kinetic properties of the processes of energy coupling in biological membranes . For this, we consider a model of a microorganism that, in its plasma membrane, expresses two electrogenic enzymes (E(1) and E(2)) transporting the same monovalent cation C and electrodiffusive paths for C and for a monovalent anion A . E(1) (E(2)) couples transport C to the reaction S(1)<-->P(1) (S(2)<-->P(2)) . We developed a mathematical model that describes the rate of change of the electrical potential difference across the membrane, of the internal concentrations of C and A, and of the concentrations of S(2) and P(2) . The enzymes are incorporated via two-state kinetic models; the passive ionic fluxes are represented by classical formulations of electrodiffusion . The microorganism volume is maintained constant by accessory regulatory devices . The model is utilized for stationary and dynamic studies for the case of bacteria employing the electrochemical gradient of Na(+) as energetic intermediate . Among other conclusions, the results show that the membrane potential represents the relevant kinetic intermediate for the overall coupling between the energy donor reaction S(1)<-->P(1) and the synthesis of S(2).

Proc Natl Acad Sci U S A, 2000 Dec 19, 97(26), 14590 - 5
Cell injury releases endogenous adjuvants that stimulate cytotoxic T cell responses; Shi Y et al.; General immunostimulants (adjuvants) are essential for generating immunity to many antigens . In bacterial infections, adjuvants are provided by components of the microorganism, e.g., lipopolysaccharide . However, it is unclear what provides the adjuvant effect for immune responses that are generated to tumors and many viruses . Here we show that cell injury and death of tumor or even normal cells provide a potent adjuvant effect for the stimulation of cytotoxic T lymphocyte responses . This adjuvant activity is constitutively present in the cytoplasm of cells and is increased in the cytoplasm of cells dying by apoptosis . The release of these components stimulates immune responses both locally and at a distance, and provides a simple mechanism to alert the immune system to potential danger in almost all pathological situations.

Curr Opin Biotechnol, 2000 Dec, 11(6), 565 - 71
Dynamic resolution and stereoinversion of secondary alcohols by chemo-enzymatic processes; Azerad R et al.; To overcome the maximum 50% yield limitation of classical resolution methods, deracemization processes involving a racemization step (dynamic resolution) or a prochiral intermediate (stereoinversion) have been developed . The use of transition metal complexes as racemizing agents, in combination with an enzymatic reaction, has been successfully extended to the deracemization of a number of simple or functionalized sec-alcohols . A two-enzyme process has been also investigated for their sequential or simultaneous deracemization . Other prominent results arise from an (apparently general) oxidoreduction process catalyzed by a single whole-cell microorganism.

Genetics, 2000 Dec, 156(4), 1949 - 58
Sequence variation at two eosinophil-associated ribonuclease loci in humans; Zhang J et al.; Host defense against invading pathogens is of great importance to the survival of higher organisms . We have been studying the evolution of mammalian eosinophil-associated ribonucleases (EARs), which are members of the ribonuclease A superfamily with known antipathogen activities . Earlier studies showed that positive selection promoted rapid diversification of paralogous EAR genes in both primates and rodents . Intraspecifically, however, it is unknown whether these genes also have divergent alleles . The recent discovery that the gene repertoire of the EAR family is much larger in rodents than in primates has led us to consider the possibility that primates maintain a large number of polymorphic alleles to compensate for a smaller gene repertoire . Here we present sequences of 2417 nucleotides at the two EAR loci, the eosinophil-derived neurotoxin (EDN, RNase 2) and eosinophil cationic protein (ECP, RNase 3), from >50 human individuals . Our data demonstrate that the nucleotide diversities (0.06-0.11%) at these loci are typical for human nuclear genes, thus permitting us to reject this polymorphism hypothesis . No significant departure from neutrality is noted and no signs of overdominant selection are observed . Similar patterns were observed in a preliminary study of chimpanzees . In summary, our results suggest that the antipathogen functions of the primate EARs are conserved after they are established and that these proteins are not currently undergoing rapid diversification in response to challenge from invading microorganisms.

Braz J Infect Dis, 1998 Dec, 2(6), 285 - 290
Morphofunctional Study of Blood Polymorphonuclear Leucocytes in HIV-Seropositive Individuals; Spada C et al.; The impairment of leukocytic functions in AIDS infected individuals, where opportunistic infections are manifested, has been under study since 1985 . However, controversy remains concerning leukocyte function during initial stages of HIV infection . In the context of the precarious immunologic and phagocytic defense of persons with AIDS, and the resulting difficulty they have to control microorganism invasion and opportunistic infections, examination of the host defense functions played by leukocytes in seropositive HIV persons is particularly important . To that end, our study sought to assess, during the initial stage of HIV infection, the laboratory parameters associated myeloid cells which are known to be altered during disease stage . Seventy-five (75) persons seropositive to HIV-1 (by the ELISA test, confirmed by immunofluorescence), and twenty-six (26) controls were tested . These individuals were screened by infectologists and their disease severity classified according to the Walter Reed Army Institute System . We observed that myeloperoxidase enzyme activity, superoxide anion production, and fungicidal action in homologous serum were all diminished in patients classified as WR-1, and progressively decreased in WR-2-4 . The percent phagocytizing neutrophils and the number of C . albicans phagocytized were normal in WR-1 patients, but diminished in WR-2-4 . We conclude that neutrophil function is diminished in HIV-infected persons at the beginning of infection, and that the defects increase as the HIV disease progresses.

J Clin Microbiol, 2000 Dec, 38(12), 4408 - 11
Detection of Chlamydia pneumoniae and Helicobacter pylori DNA in human atherosclerotic plaques by PCR; Farsak B et al.; Chlamydia pneumoniae and Helicobacter pylori can cause persistent infections of the respiratory and gastrointestinal tract, respectively . It has been suggested that persistent infection of arteries with these bacteria can contribute to the development of atherosclerosis . The aims of this study were to determine the presence of C . pneumoniae and H . pylori DNA in atherosclerotic plaque samples by PCR and to evaluate the correlation between clinical status and DNA positivity of these bacteria . Eighty-five consecutive patients (mean age, 59 +/- 10; 75 male, 10 female) undergoing coronary artery bypass grafting, carotid endarterectomy, and surgery of the abdominal aorta for atherosclerotic obstructive lesions were included in the study . Forty-six endarterectomy specimens from the atherosclerotic lesions and 39 specimens from healthy regions of the ascending aorta, which were accepted as the control group, were excised . The presence of microorganism DNA in endarterectomy specimens was assessed by PCR . C . pneumoniae DNA was found in 12 (26%) of 46 endarterectomy specimens and none of the healthy vascular-wall specimens (P < 0.001), while H . pylori DNA was found in 17 (37%) of 46 endarterectomy specimens and none of the controls (P < 0.001) . Either C . pneumoniae or H . pylori DNA was positive in 23 (50%) of 46 patients and none of the controls (P < 0 . 001) . Six of the atherosclerotic lesions showed coexistence of both of the microorganism DNAs . The presence of C . pneumoniae and H . pylori DNA in a considerable number of atherosclerotic plaques but their absence in healthy vascular wall supports the idea that they may have a role in the development of atherosclerosis, especially in countries where infection is prevalent and where conventional risk factors fail to explain the high prevalence of atherosclerotic vascular disease.

Semin Cancer Biol, 2000 Oct, 10(5), 331 - 40
Requirement for reverse immune surveillance for the growth of germinal center-derived murine lymphomas; Ponzio NM et al.; The concept of reverse immune surveillance, first conceived over 12 years ago, described the relationship that existed between germinal center-derived B cell lymphoma cells and the host immune system in SjL/J mice . According to reverse immune surveillance, recognition of tumor cell antigens and a response by the host immune system is required for tumor growth . The phenomenon of reverse immune surveillance related to B cell lymphomas has recently also been characterized in another inbred mouse strain, C57L/J . Moreover, elements of reverse immune surveillance have been observed in several other mouse strains that develop B cell lymphomas, suggesting that this lymphomagenic mechanism may be more common than first envisioned . In SJL and C57L mice, the B lymphoma cells express an MMTV-encoded superantigen (vSAg29) that stimulates syngeneic CD4+ T cells bearing Vbeta16 in their TCR . In contrast to the mRNAs for other MMTVs in normal mouse B cells, vSAg29 mRNA initiates in the env (META) region, undergoes splicing in the 3' env region, and continues through the 3' LTR . Copious cytokine production, including IFN-gamma, IL-4 and IL-5 accompanies the response of the T cells to this vSAg . In addition to cytokines produced by vSAg-responsive T cells, more recent evidence indicates that another cytokine, LTalphabeta2, which is expressed on the lymphoma cell surface, also plays a role in the promotion of the B cell lymphoma growth . It is possible that interaction with LTbeta-R on follicular dendritic cells or other stromal elements facilitates tumor growth by preventing apoptosis of the malignant B cells . To what degree these findings in the mouse are relevant to the development and/or growth of human B lymphoma cells remains to be determined . However, endogenous retroviral sequences do exist in the human genome . Interestingly, some of these sequences are homologous to MMTV, and are transcribed in B lymphoblastoid cells . Moreover microorganisms that are infectious for human B cells, such as EBV and Herpes Virus 8, may also produce superantigens.

Med Trop (Mars), 2000, 60(2), 171 - 8
{Dangerous sharks in tropical seas}; Maslin J et al.; Sightseeing travel in tropical zones is a growing industry . The risks incurred by travelers depend on the destination, duration of stay, individual behavior, and type of leisure activity . Water sports expose visitors to encounters with dangerous marine animals . Shark attacks are rare but always serious occurrences . Divers should handle any shark, regardless of size, with due precaution . Prevention of shark attack depends on avoiding encounters by not attracting the attention of the shark and knowing the proper attitude to adopt in case an encounter should occur . Active and passive protection can be used, but each method has advantages and disadvantages depending on the situation . Rescue operations are difficult due to the gravity of injuries and their occurrence in a marine environment . This along with the nature of the aggressor explain that many attacks are immediately fatal . Wounds are often deep with involvement of bone, blood vessels, and nerves . A possible source of complication in survivors is infection, which can involve uncommon microorganisms associated with bacteria in sharks mouth or marine environment.

Nat Med, 2000 Dec, 6(12), 1348 - 54
Efficient presentation of exogenous antigen by liver endothelial cells to CD8+ T cells results in antigen-specific T-cell tolerance; Limmer A et al.; Myeloid antigen-presenting cells (APC) are known to cross-present exogenous antigen on major histocompatibility class I molecules to CD8+ T cells and thereby induce protective immunity against infecting microorganisms . Here we report that liver sinusoidal endothelial cells (LSEC) are organ-resident, non-myeloid APC capable of cross-presenting soluble exogenous antigen to CD8+ T cells . Though LSEC employ similar molecular mechanisms for cross-presentation as dendritic cells, the outcome of cross-presentation by LSEC is CD8+ T cell tolerance rather than immunity . As uptake of circulating antigens into LSEC occurs efficiently in vivo, it is likely that cross-presentation by LSEC contributes to CD8+ T cell tolerance observed in situations where soluble antigen is present in the circulation.

Microbes Infect, 2000 Oct, 2(12), 1523 - 35
Use of fluorescent probes to assess physiological functions of bacteria at single-cell level; Joux F et al.; A wide diversity of fluorescent probes is currently available to assess the physiological state of microorganisms . The recent development of techniques such as solid-phase cytometry, the increasing sensitivity of fluorescence tools and multiparametric approaches combining taxonomic and physiological probes have improved the effectiveness of direct methods in environmental and industrial microbiology.

Neth J Med, 2000 Dec, 57(6), 215 - 23
Totally implantable venous access devices: evaluation of complications and a prospective comparative study of two different port systems; Hartkamp A et al.; BACKGROUND: Totally implantable venous access devices (TIVADs) are valuable instruments in case prolonged intravenous therapy is required, but implantation and use of these devices are associated with complications . The purpose of this study was to evaluate perioperative and long-term complications associated with TIVADs . In addition, we compared two different types of TIVADs with respect to implantation, care protocol and patients' comfort . METHODS: In a retrospective study perioperative and long-term complications in a general oncology population were analysed . In a prospective randomized study comparison of two types of TIVADs was carried out . RESULTS: Perioperative complications occurred in 27 (21.4%) of 126 implanted TIVADs: catheter malposition (16.7%) in 21 patients, pneumothorax (0.8%) in one and haemorrhage (4.0%) in five . Long-term complications appeared in 31 (25.2%) out of 123 TIVADs: thrombosis in 9 (7.3%), especially associated with malposition of the tip of the catheter; infection in 10 (8.1%); extravasation in 2 (1.6%); migration of the catheter tip in 6 (4.8%); pain at reservoir in 3 (2.4%) and inaccessibility of the port in 1 (0.8%) . No significant differences were found with respect to implantation, care accessibility and patients' comfort between the two TIVADs . CONCLUSIONS: The use of TIVADs is associated with some risk of serious perioperative and long-term complications . In case of thrombotic complications these systems can be saved with appropriate treatment . Correct positioning of the catheter tip is essential to prevent thrombotic complications . In case of TIVAD-related infectious complications, the possibility of saving the TIVAD depends on the causative microorganism and type of infection . Furthermore, to increase patients' satisfaction with TIVADs they should be well informed about the surgical procedure and possible disadvantages of these devices.

Scand J Gastroenterol, 2000 Oct, 35(10), 1033 - 40
Different patterns of Helicobacter pylori adherence to gastric mucosa cells in children and adults . An ultrastructural study; Blom J et al.; BACKGROUND: Infection with Helicobacter pylori in childhood may be the initiation of a lifelong coexistence between microorganisms and epithelial cells resulting in chronic inflammation . The adhesion pattern of H . pylori found in antral biopsies from a group of H . pylori-infected children with recurrent abdominal pain was compared with a group of H . pylori-infected adults suffering from dyspepsia, in an attempt to reveal differences in the type of adhesion . METHODS: The histology of antrum biopsies and the ultrastructure of adherent H . pylori in biopsies from 26 children (median age, 10.1 years) were compared with organisms in biopsies from 19 adults (median age, 54.4 years) . RESULTS: More than 1000 adherent H . pylori were studied and divided into four types of adhesion: 1) contact to microvilli; 2) connection to the plasma membrane via filamentous material; 3) adhesive pedestal formation; and 4) abutting or making a depression in the plasma membrane . Contact to microvilli was significantly higher (69% versus 39%; P = 0.002) in children compared with adults and comprised two-thirds of all adherent organisms in children . The more intimate adhesion types as abutting or adhesive pedestals dominated in adults . CONCLUSIONS: These results indicate a change in contact types between H . pylori and gastric epithelial cells in adults compared with children and this may be a natural development in the lifelong infection of humans.

Crit Rev Biochem Mol Biol, 2000, 35(5), 317 - 37
The production of pyrethrins by plant cell and tissue cultures of Chrysanthemum cinerariaefolium and Tagetes species; Hitmi A et al.; Pyrethrins, the most economically important natural insecticide, comprise a group of six closely related monoterpene esters . The industrial production is based on their extraction from Chrysanthemum cinerariaefolium (Pyrethrum) capitula . The world production of natural pyrethrins still falls short of global market demand stimulating the research in in vitro production as an alternative to conventional cultivation methods . The different biotechnological alternatives such as callus cultures, shoot and root cultures, plant cell suspension cultures, and bioconversion of precursors by means of enzymatic synthesis or genetically engineered microorganisms, as well as the progress achieved in methods for the identification and quantitation of insecticidal compounds have been reviewed . Although technology for plant cell culture exists, industrial applications have, to date, been limited due to both the low economical viability and technological feasibility at large scale . Bioconversion of readily available precursors looks more attractive, but more research is needed before this technology is used for the industrial production of pyrethrins.

FEMS Microbiol Ecol, 2000 Sep 1, 33(3), 191 - 196
Spatial distribution of protists in the presence of macroaggregates in a marine system; Artolozaga I I et al.; The spatial distribution of marine protistan communities in the presence of organic macroaggregates, formed from natural seawater, was studied in several microcosm experiments . The presence of macroaggregates had two main effects . First, the size of the communities of bacteria, flagellates and ciliates increased, as these communities were three orders of magnitude higher in the aggregates than in the microcosm water . In addition, it brought the diversification on the niches accessible to planktonic microorganisms, as three phases were formed: water, aggregates and aggregate-water interphase . Some of the detected protistan taxa were only found in the water, and therefore they can be considered as truly free-swimming protists . Others quickly colonised the aggregates, and finally, some of them showed a preference for the aggregate-water interphase . We discuss this spatial structuring of the protistan community on the basis of their feeding strategies and structural and behavioural characteristics.

Biofizika, 2000 Sep-Oct, 45(5), 882 - 7
{Mathematical model of microorganism biomass growth in the absence of a limiting substrate and inhibiting agents}; Shelykh IA et al.; A mathematical model for the growth of microbial cells upon submerged cultivation was constructed . The model describes the growth phases of the biomass of microorganisms in the absence of inhibiting agents and limitation by substrate in the medium . At the basis of model is the requirement that cells should not be in physical contact during some time in order that they can divide . The model involves the known concepts of statistical physics . The consequences of the model are discussed.

Br J Anaesth, 2000 Nov, 85(5), 735 - 9
Gram staining of protected pulmonary specimens in the early diagnosis of ventilator-associated pneumonia; Mimoz O et al.; We evaluated prospectively the use of Gram staining of protected pulmonary specimens to allow the early diagnosis of ventilator-associated pneumonia (VAP), compared with the use of 60 bronchoscopic protected specimen brushes (PSB) and 126 blinded plugged telescopic catheters (PTC) obtained from 134 patients . Gram stains were from Cytospin slides; they were studied for the presence of microorganisms in 10 and 50 fields by two independent observers and classified according to their Gram stain morphology . Quantitative cultures were performed after serial dilution and plating on appropriate culture medium . A final diagnosis of VAP, based on a culture of > or = 10(3) c.f.u . ml-1, was established after 81 (44%) samplings . When 10 fields were analysed, a strong relationship was found between the presence of bacteria on Gram staining and the final diagnosis of VAP (for PSB and PTC respectively: sensitivity 74 and 81%, specificity 94 and 100%, positive predictive value 91 and 100%, negative predictive value 82 and 88%) . The correlation was less when we compared the morphology of microorganisms observed on Gram staining with those of bacteria obtained from quantitative cultures (for PSB and PTC respectively: sensitivity 54 and 69%, specificity 86 and 89%, positive predictive value 72 and 78%, negative predictive value 74 and 84%) . Increasing the number of fields read to 50 was associated with a slight decrease in specificity and positive predictive value of Gram staining, but with a small increase in its sensitivity and negative predictive value . The results obtained by the two observers were similar to each other for both numbers of fields analysed . Gram staining of protected pulmonary specimens performed on 10 fields predicted the presence of VAP and partially identified (using Gram stain morphology) the microorganisms growing at significant concentrations, and could help in the early choice of the treatment of VAP . Increasing the number of fields read or having the Gram stain analysed by two independent individuals did not improve the results.

Annu Rev Genet, 2000, 34, 139 - 164
Assessment of bacterial pathogenesis by analysis of gene expression in the host; Mahan MJ et al.; A number of techniques have been developed to assess the expression of microbial virulence genes within the host (in vivo) . These studies have shown that bacteria employ a wide variety of mechanisms to coordinately regulate the expression of these genes during infection . Two tenets have emerged from these studies: bacterial adaptation responses are critical to growth within the host, and interactions between microorganisms and the microenvironments of their hosts cannot be revealed from in vitro studies alone . Results that support these tenets include (i) the prevalent class of in vivo expressed genes are involved in adaptation to environmental stresses, (ii) pathogens recovered from host tissues (versus laboratory growth) are often more resistant to host killing mechanisms, and (iii) virulence gene expression can differ in the animal compared to laboratory media . Thus, pathogenicity comprises the unique ability to adapt to the varied host milieus encountered as the infection proceeds.

DNA Seq, 2000, 11(3-4), 183 - 92
A BAC library and paired-PCR approach to mapping and completing the genome sequence of Sulfolobus solfataricus P2; She Q et al.; The original strategy used in the Sulfolobus solfataricus genome project was to sequence non overlapping, or minimally overlapping, cosmid or lambda inserts without constructing a physical map . However, after only about two thirds of the genome sequence was completed, this approach became counter-productive because there was a high sequence bias in the cosmid and lambda libraries . Therefore, a new approach was devised for linking the sequenced regions which may be generally applicable . BAC libraries were constructed and terminal sequences of the clones were determined and used for both end mapping and PCR screening . The PCR approaches included a novel chromosome walking method termed "paired-PCR" . 21 gaps were filled by BAC end sequence analyses and 6 gaps were filled by PCR including three large ones by paired-PCR . The complete map revealed that 0.9 Mb remained to be sequenced and 34 BAC clones were selected for walking over small gaps and preparing template libraries for larger ones . It is concluded that an optimal strategy for sequencing microorganism genomes involves construction of a high-resolution physical map by BAC end analyses, PCR screening and paired-PCR chromosome walking after about half the genome sequence has been accumulated.

Adv Biochem Eng Biotechnol, 2000, 70, 35 - 40
Antibiotica research in Jena from penicillin and nourseothricin to interferon; Bocker H et al.; Milestones of antibiotics research and biotechnology in Jena/Thuringia are: 1938--Hans Knoll established a strain collection of microorganisms; 1942--production of penicillin on laboratory scale by Hans Knoll; since 1945--development of industrial production processes for penicillin and streptomycin; 1952--production of BCG-vaccine; since 1956--development of biotechnical processes in the Institute of Microbiology and Experimental Therapy for actinomycin C, oxytetracyclin, erythromycin, paromomycin, turimycin, griseofulvin, nystatin, and nourseothricin, and in the 1980s for streptokinase, staphylokinase, and interferons . After the German unification the Hans-Knoll-Institute for Natural Products Research was founded.

Am Surg, 2000 Nov, 66(11), 1004 - 10
Zinc, copper, and metallothionein metabolism after jejunoileal bypass surgery or small bowel resection in rats; Rodriguez JA et al.; Liver dysfunction is a frequent complication of jejunoileal bypass (JIB) surgery, a procedure commonly used until recently to treat morbid obesity . It has been suggested that liver failure in JIB patients is due to bacterial overgrowth and translocation from the bypassed intestine . Because invading microorganisms cause hepatic inflammation these experiments evaluated zinc, copper, and metallothionein (MT) in two experimental rat models of intestinal surgery to determine whether their distribution in plasma and tissues was similar to the highly characteristic pattern observed during an inflammatory response . In the JIB rat model 90 per cent of the small intestine was isolated from the flow of digesta but remained viable in the abdominal cavity . In the small bowel resection (SBR) model 90 per cent of the small intestine was removed and the remaining intestine was resected . Data collected 21 days after surgery showed decreased growth rate and plasma zinc in the SBR and JIB rats that was significantly improved by supplemental zinc . All other measures of zinc, copper, and MT metabolism in the SBR rats were similar to those of controls . In JIB rats, however, liver copper, MT protein, and MT mRNA were significantly elevated, and a high proportion of the intracellular zinc and copper was associated with MT . The pattern of zinc, copper, and MT distribution in systemic circulation and liver of JIB rats suggests hepatic inflammation superimposed on low zinc and copper status . Lack of a similar response in the SBR rats confirms the involvement of the bypassed intestinal segment and supports the hypothesis that bacterial overgrowth and translocation are responsible for liver inflammation and dysfunction in JIB patients.

Z Gastroenterol, 2000 Oct, 38(10), 855 - 72
{The mechanisms of antigen uptake in the small and large intestines: the roll of the M cells for the initiation of immune responses}; Gebert A et al.; The gut-associated lymphoid tissues, e.g., the Peyer's patches and the appendix, constantly internalize antigenic material to rapidly generate an immune response, if necessary . This sampling of antigens is performed by specialized epithelial cells, the "membranous" or "microfold" (M) cells of the dome epithelia . M cells possess a unique ultrastructure and are typically in contact with lymphoid cells . They endocytose macromolecules and particles, including entire microorganisms, at their apical membrane, transport these in vesicles to their basolateral membrane, and exocytose them to the intercellular space . This article reviews the structural and functional characteristics of M cells in the digestive tract in humans and other species . Specializations of M cells for antigen uptake and transport comprise the composition of their apical membrane, a modified cytoskeleton as compared to enterocytes, and a large pocket-like invagination of the basolateral membrane populated by lymphocytes . Besides ultrastructural characteristics, histochemical markers are listed that are available for detecting M cells . The origin and differentiation pathways of M cells and enterocytes of the dome epithelium are outlined and critically commented on . Because M cells are known entry sites of various pathogens and, in the future, might be employed for the oral application of drugs and vaccines, the clinical relevance of M cells in health and disease is discussed.

Mol Biochem Parasitol, 2000 Nov, 111(1), 95 - 105
Identification of six Trypanosoma cruzi lineages by sequence-characterised amplified region markers; Brisse S et al.; Six discrete phylogenetic lineages were recently identified in Trypanosoma cruzi, on the basis of multilocus enzyme electrophoresis and random amplified polymorphic DNA (RAPD) characterisation . The objective of the present study was to develop specific PCR-based markers for the identification of each of the six lineages . Eighty-seven T . cruzi stocks representative of all the lineages were characterised by RAPD with three primers, resulting in the identification of three fragments that were specifically amplified in the given sets of lineages . After cloning and sequencing these fragments, three pairs of sequence-characterised amplified region (SCAR) primers were designed . After PCR amplification using the SCAR primers, the initial polymorphism was retained either as the presence or absence of amplification, or as size variation between the PCR products . Although most PCR products, taken individually, were distributed across several lineages, the combination of the three SCAR markers resulted in characteristic patterns that were distinct in the six lineages . Furthermore, T . cruzi lineages were distinguished from Trypanosoma rangeli, T . cruzi marinkellei and T . cruzi-like organisms . The excellent correspondence of these new PCR markers with the phylogenetic lineages, allied with their sensitivity, makes them reliable tools for lineage identification and strain characterisation in T . cruzi . The approach described here could be generalised to any species of microorganism harbouring clear-cut phylogenetic subdivisions.

J Infect Dis, 2001 Jan 1, 183(1), 119 - 24 Epub 2000 Nov 16.
Biological selection of variant-specific surface proteins in Giardia lamblia; Singer SM et al.; Immune evasion is frequently cited as the main reason for antigenic variation in pathogenic microorganisms . To better understand the role of switching of variant-specific surface proteins (VSPs) in Giardia lamblia-host interactions, antigenic variation during infections of mice and gerbils was examined, using clones that predominantly expressed unique VSPs . As expected, VSPs were selected against during infections of immunocompetent hosts . In contrast, in immunodeficient hosts, some VSPs were selected for and others were selected against . These diverse patterns of selection demonstrate that there are host-VSP interactions that exert both positive and negative selective pressures on parasites, independent of the adaptive immune response . Furthermore, selection was dependent on both the particular VSP and the host . Thus, the large number of VSP genes in G . lamblia may allow the parasite to infect multiple different hosts, and antigenic variation could be a mechanism to expand the parasite's host range.

J Biochem Biophys Methods, 2000 Nov 20, 46(1-2), 1 - 9
A microcalorimetric method for studying the biological effects of La(3+) on Escherichia coli; Ruming Z et al.; A microcalorimetric technique based on the bacterial heat-output was explored to evaluate the stimulatory effect of La(3+) on Escherichia coli . The power-time curves of the growth metabolism of E . coli and the effect of La(3+) on it were studied using an LKB-2277 BioActivity Monitor, stopped-flow method, at 37 degrees C . For evaluation of the results, the maximum power (P(max)), the growth rate constants (k) and the heat effects (Q(LOG), Q(STAT)) for the log phase, the stationary phase and the total heat effect (Q(T)) for E . coli were determined . The microcalorimetric method agreed with the conventional methods, such as cell numbers and biomass . La(3+) in the concentration ranges of 0-400 microg/ml has stimulatory effects on E . coli, while La(3+) ion of higher concentrations (>400 microg/ml) can inhibit the growth . This phenomenon is very similar to those observed from the in vitro cells and tissues from animals, plants and some microorganisms by other methods.

Bioessays, 2000 Dec, 22(12), 1067 - 74
Adaptive mutation: implications for evolution; Foster PL; Adaptive mutation is defined as a process that, during nonlethal selections, produces mutations that relieve the selective pressure whether or not other, nonselected mutations are also produced . Examples of adaptive mutation or related phenomena have been reported in bacteria and yeast but not yet outside of microorganisms . A decade of research on adaptive mutation has revealed mechanisms that may increase mutation rates under adverse conditions . This article focuses on mechanisms that produce adaptive mutations in one strain of Escherichia coli, FC40 . These mechanisms include recombination-induced DNA replication, the placement of genes on a conjugal plasmid, and a transient mutator state . The implications of these various phenomena for adaptive evolution in microorganisms are discussed.

J Endourol, 2000 Oct, 14(8), 689 - 92
Transurethral microwave thermotherapy for the treatment of prostatitis; Liatsikos EN et al.; The lethal action of microwaves on various microorganisms is well established and has been exploited in various clinical settings . Transurethral microwave thermotherapy (TUMT) has become a recognized modality for the treatment of prostatic diseases . Recently, it has been applied for the treatment of patients with nonbacterial prostatitis unresponsive to traditional therapeutic schemes . We review the current literature and present our recent encouraging experience with the in vitro bactericidal effect of microwaves on bacteria considered possible etiologic agents of prostatitis . Thus, we may consider the application of TUMT in patients with chronic bacterial prostatitis.

J Mol Biol, 2000 Nov 24, 304(2), 219 - 29
High precision NMR structure of YhhP, a novel Escherichia coli protein implicated in cell division; Katoh E et al.; YhhP, a small protein of 81 amino acid residues encoded by the yhhP gene in the Escherichia coli database, is implicated in cell division although the precise biological function of this protein has not been yet identified . A variety of microorganisms have similar proteins, all of which contain a common CPxP sequence motif in the N-terminal region . We have determined the three-dimensional solution structure of YhhP by NMR spectroscopy in order to obtain insight into its biological function . It folds into a two-layered alpha/beta-sandwich structure with a betaalphabetaalphabetabeta fold, comprising a mixed four-stranded beta-sheet stacked against two alpha-helices, both of which are nearly parallel to the strands of the beta-sheet . The CPxP motif plays a significant structural role in stabilizing the first helix as a part of the new type N-capping box where the Cys-Pro peptide bond adopts a cis configuration . The structure of YhhP displays a striking resemblance to the C-terminal ribosome-binding domain of translation initiation factor IF3 (IF3C) . In addition, the surface charge distribution of the RNA-recognition helix of IF3C is nearly the same as that of the corresponding helix of YhhP . These results suggest a structure-based hypothesis in which binding to an RNA target plays an essential role in the function of this ubiquitous protein .

Microb Ecol, 2000 Aug, 40(3), 260 - 272
"BACWAVE," a Spatial-Temporal Model for Traveling Waves of Bacterial Populations in Response to a Moving Carbon Source in Soil; Zelenev VV et al.; Previously, we discovered the phenomenon of wavelike spatial distributions of bacterial populations and total organic carbon (TOC) along wheat roots . We hypothesized that the principal mechanism underlying this phenomenon is a cycle of growth, death, autolysis, and regrowth of bacteria in response to a moving substrate source (root tip) . The aims of this research were (i) to create a simulation model describing wavelike patterns of microbial populations in the rhizosphere, and (ii) to investigate by simulation the conditions leading to these patterns . After transformation of observed spatial data to presumed temporal data based on root growth rates, a simulation model was constructed with the Runge-Kutta integration method to simulate the dynamics of colony-forming bacterial biomass, with growth and death rates depending on substrate content so that the rate curves crossed over at a substrate concentration within the range of substrate availability in the model . This model was named "BACWAVE," standing for "bacterial waves." Cyclic dynamics of bacteria were generated by the model that were translated into traveling spatial waves along a moving nutrient source . Parameter values were estimated from calculated initial substrate concentrations and observed microbial distributions along wheat roots by an iterative optimization method . The kinetic parameter estimates fell in the range of values reported in the literature . Calculated microbial biomass values produced spatial fluctuations similar to those obtained for experimental biomass data derived from colony forming units . Concentrations of readily utilizable substrate calculated from biomass dynamics did not mimic measured concentrations of TOC, which consist not only of substrate but also various polymers and humic acids . In conclusion, a moving pulse of nutrients resulting in cycles of growth and death of microorganisms can indeed explain the observed phenomenon of moving microbial waves along roots . This is the first report of wavelike dynamics of microorganisms in soil along a root resulting from the interaction of a single organism group with its substrate.

Microb Ecol, 2000 Aug, 40(3), 250 - 259
Wavelike Distributions of Microbial Populations along an Artificial Root Moving through Soil; van Bruggen AH et al.; In a previous paper, we described wavelike distributions of bacterial populations along roots of wheat, and hypothesized that one mechanism underlying these distributions might be growth and death cycles of microorganisms in response to a moving nutrient source, the root tip . Similar wavelike distributions in microbial biomass were obtained using a simulation model for growth and death of bacteria in relation to their substrate (BACWAVE) . The model was parameterized with data from one experiment on rhizosphere bacterial populations along wheat roots, and compared against a similar but independent experiment . In experiments described in this paper, similar wavelike distributions in bacterial populations were observed in response to a single artificial exudate moving linearly through a soil that had been air-dry for almost 2 years . The period of the spatial waves was longer when the tip of the artificial exudate moved at a speed of 4.2 cm/day compared to a tip moving at 1.1 cm/day, but after transformation into the temporal domain, the periods of the waves were similar for both moving speeds . The observed distributions were simulated using the BACWAVE model with similar parameter values as derived from the experiment with wheat roots mentioned above . The results presented in this paper confirm our hypothesis that wavelike distributions of bacterial population along plant roots can arise from "exudates" released primarily from the root tip, without the need for additional exudation points.

Proc Natl Acad Sci U S A, 2000 Nov 21, 97(24), 13092 - 6
Measuring the forces involved in polyvalent adhesion of uropathogenic Escherichia coli to mannose-presenting surfaces; Liang MN et al.; Mechanisms of bacterial pathogenesis have become an increasingly important subject as pathogens have become increasingly resistant to current antibiotics . The adhesion of microorganisms to the surface of host tissue is often a first step in pathogenesis and is a plausible target for new antiinfective agents . Examination of bacterial adhesion has been difficult both because it is polyvalent and because bacterial adhesins often recognize more than one type of cell-surface molecule . This paper describes an experimental procedure that measures the forces of adhesion resulting from the interaction of uropathogenic Escherichia coli to molecularly well defined models of cellular surfaces . This procedure uses self-assembled monolayers (SAMs) to model the surface of epithelial cells and optical tweezers to manipulate the bacteria . Optical tweezers orient the bacteria relative to the surface and, thus, limit the number of points of attachment (that is, the valency of attachment) . Using this combination, it was possible to quantify the force required to break a single interaction between pilus and mannose groups linked to the SAM . These results demonstrate the deconvolution and characterization of complicated events in microbial adhesion in terms of specific molecular interactions . They also suggest that the combination of optical tweezers and appropriately functionalized SAMs is a uniquely synergistic system with which to study polyvalent adhesion of bacteria to biologically relevant surfaces and with which to screen for inhibitors of this adhesion.

Tsitologiia, 2000, 42(9), 891 - 5
{The effect of media tonicity on Escherichia coli resistance to heating with different gradient}; Morozov II et al.; The influence of NaCl water solutions and glycerine hypertonic concentration on the survival of bacteria Escherichia coli B/r heated with different values of heat drop was investigated . It was shown that the transfer of cell suspensions from isotonic conditions to media with raised osmotic pressure, preliminarily heated up to 60 degrees C, and the following heating at this temperature inhibited differences in cell sensitivity to heating at different heat drop . Unlike, it was found that the transfer of cell suspensions from isotonic conditions to hypertonic media before and after heating at 60 degrees C increased differences in resistance of these microorganisms to heating at different heat drop . It is proposed that different resistance of bacteria to damaging action of hyperthermia at different heat drop, and a modified influence of hypertonic solutions on these differences may be due to heat induced destabilization of cell osmotic homeostasis . The extent of expression of this destabilization may be determined by a quantitative ratio of osmotic pressure values in the cell-suspension medium system in particular temperature and tonic environmental conditions.

Oral Surg Oral Med Oral Pathol Oral Radiol Endod, 2000 Nov, 90(5), 647 - 50
Bacterial leakage in coronally unsealed root canals obturated with 3 different techniques; Siqueira JF Jr et al.; OBJECTIVE: The purpose of this in vitro study was to evaluate the coronal leakage of microorganisms from saliva into root canals filled by 3 obturation techniques . STUDY DESIGN: Obturated canals were mounted in an apparatus and then exposed to human saliva . The number of days required for the entire contamination of the root canal was recorded . Evaluation was carried out for 60 days . RESULTS: Regardless of the technique used, a significant number of specimens were contaminated after 30 and 60 days . No significant differences were detected among the techniques (P >.05) . CONCLUSIONS: Results indicated that none of the techniques tested could predictably produce a coronal bacteria-tight seal of the root canal after direct saliva challenge.

FEMS Microbiol Rev, 2000 Dec, 24(5), 591 - 9
Microbial interactions involving sulfur bacteria: implications for the ecology and evolution of bacterial communities; Overmann J et al.; A major goal of microbial ecology is the identification and characterization of those microorganisms which govern transformations in natural ecosystems . This review summarizes our present knowledge of microbial interactions in the natural sulfur cycle . Central to the discussion is the recent progress made in understanding the co-occurrence in natural ecosystems of sulfur bacteria with contrasting nutritional requirements and of the spatially very close associations of bacteria, the so-called phototrophic consortia (e.g . 'Chlorochromatium aggregatum' or 'Pelochromatium roseum') . In a similar way, microbial interactions may also be significant during microbial transformations other than the sulfur cycle in natural ecosystems, and could also explain the low culturability of bacteria from natural samples.

FEMS Microbiol Rev, 2000 Dec, 24(5), 555 - 65
Ribosomal RNA-targeted nucleic acid probes for studies in microbial ecology; Amann R et al.; With readily applicable hybridization assays, mainly based on rRNA-targeted nucleic acid probes, and direct, cultivation-independent sequence retrieval, microbiologists can for the first time determine the true composition of microbial communities . Phylogenetic identification and exact spatiotemporal quantification of microorganisms will in the future become prerequisites for high quality studies in microbial ecology just as good taxonomy and solid quantification have always been for macroecology . This review is intended to give a short history of the development of rRNA-targeted nucleic acid probes and probe technologies, as well as of their application in microbial ecology . The current state of the art is described, and we will try to look into the future . Over the last decade, rRNA-targeted probes have become a handy tool for microbial ecologists . In order to speed up the transformation of microbial ecology from a mostly descriptive to a hypothesis-driven, experimental science more intense use must be made of the taxonomic precision and quantitativeness of rRNA-targeted probes.

Biol Chem, 2000 Sep-Oct, 381(9-10), 965 - 72
Macromolecular intelligence in microorganisms; Bruggeman FJ et al.; Biochemistry and molecular biology have been focusing on the structural, catalytic, and regulatory properties of individual macromolecules from the perspective of clarifying the mechanisms of metabolism and gene expression . Complete genomes of 'primitive' living organisms seem to be substantially larger than necessary for metabolism and gene expression alone . This is in line with the findings of silent phenotypes for supposedly important genes, apparent redundancy of functions, and variegated networks of signal transduction and transcription factors . Here we propose that evolutionary optimization has been much more intensive than to lead to the bare minima necessary for autonomous life . Much more complex organisms prevail . Much of this complexity arises in the nonlinear interactions between cellular macromolecules and in subtle differences between paralogs (isoenzymes) . The complexity can only be understood when analyzed quantitatively, for which quantitative experimentation is needed in living systems that are as simple and manipulatable as possible, yet complex in the above sense . We illustrate this for the glutamine synthetase cascade in Escherichia coli . By reviewing recent molecular findings, we show that this cascade is much more complex than necessary for simple regulation of ammonia assimilation . Simulations suggest that the function of this complexity may lie in quasi-intelligent behavior, including conditioning and learning.

Biol Chem, 2000 Sep-Oct, 381(9-10), 911 - 20
Metabolic networks: a signal-oriented approach to cellular models; Lengeler JW; Complete genomes, far advanced proteomes, and even 'metabolomes' are available for at least a few organisms, e.g., Escherichia coli . Systematic functional analyses of such complete data sets will produce a wealth of information and promise an understanding of the dynamics of complex biological networks and perhaps even of entire living organisms . Such complete and holistic descriptions of biological systems, however, will increasingly require a quantitative analysis and the help of mathematical models for simulating whole systems . In particular, new procedures are required that allow a meaningful reduction of the information derived from complex systems that will consequently be used in the modeling process . In this review the biological elements of such a modeling procedure will be described . In a first step, complex living systems must be structured into well-defined and clearly delimited functional units, the elements of which have a common physiological goal, belong to a single genetic unit, and respond to the signals of a signal transduction system that senses changes in physiological states of the organism . These functional units occur at each level of complexity and more complex units originate by grouping several lower level elements into a single, more complex unit . To each complexity level corresponds a global regulator that is epistatic over lower level regulators . After its structuring into modules (functional units), a biological system is converted in a second step into mathematical submodels that by progressive combination can also be assembled into more aggregated model structures . Such a simplification of a cell (an organism) reduces its complexity to a level amenable to present modeling capacities . The universal biochemistry, however, promises a set of rules valid for modeling biological systems, from unicellular microorganisms and cells, to multicellular organisms and to populations.

J Clin Periodontol, 2000 Nov, 27(11), 846 - 53
Bacterial susceptibility to amoxicillin and potassium clavulanate in advanced periodontitis patients not responding to mechanical therapy; Kleinfelder JW et al.; BACKGROUND, AIMS: Between 4 and 8% of periodontitis patients are reported to respond poorly to conventional therapy . In these cases, adjunctive use of systemic antibiotics might be a reasonable therapeutic approach . The purpose of this study was to evaluate the effects of systemic amoxicillin/clavulanate as adjunct to periodontal surgery on the predominant subgingival microorganisms in patients not responding to mechanical therapy . Furthermore, the bacterial susceptibility to amoxicillin/clavulanate was analyzed before and after therapy in order to assess the clinical validity of pre-therapeutic susceptibility testing . METHODS: In 10 periodontitis subjects with no subgingival detection of Actinobacillus actinomycetemcomitans, the predominant subgingival organisms were identified using the identification system Rapid ID 32 A as well as antibiotic susceptibility was tested utilizing the E test . RESULTS: Porphyromonas gingivalis and Prevotella oralis were detected in 7/10 subjects and could no more recovered after therapy . Fusobacterium nucleatum and Peptostreptococcus micros were present in 5/10 patients before treatment, but could be detected in 6/10, resp . 3/10 after therapy . In 4/10 subjects harboring F . nucleatum and in 3/10 with P . micros, those organisms were not targeted by amoxicillin/clavulanate, although post-treatment testing revealed their alleged susceptibility (MICs varied from 0.023 to 0.032 microg/ml, resp . from 0.125 to 2.0 microg/ ml) . CONCLUSIONS: The results of this study suggest that the outcomes of conventional methods of susceptibility testing have to be interpreted very carefully when being used for treatment of plaque-related diseases . Furthermore, since the endpoint of systemic antibiotic treatment as adjunct to conventional therapy is elimination of F . nucleatum or P . micros in patients harboring these organisms, the use of amoxicillin/clavulanate appears not to be justified.

J Environ Sci Health B, 2000 Nov, 35(6), 677 - 87
Atrazine degradation in a containerized rhizosphere system; Costa RM et al.; The effect of atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine) on rhizosphere microorganisms and its fate in a containerized rhizosphere system was studied . The rhizosphere system consisted of corn grown in pot containing a defined potting mix of sand and bark with atrazine . Sterilized potting mix and a container without plants served as controls . Atrazine was extracted and analyzed via HPLC . Fluorescent pseudomonad populations increased 100-fold in the rhizposphere during a 60-day incubation period as compared to the nonvegetated control . Atrazine degradation was higher in the rhizosphere system (half-life of 7 days) compared to the nonvegetated control (half-life of greater than 45 days) . The major degradation product detected in the rhizosphere system was deisopropylatrazine; other products detected included deethylatrazine, deethylhydroxyatrazine, deisopropylatrazine and hydroxyatrazine . Hydroxyatrazine was detected in the nonvegetated and sterile controls . The containerized rhizosphere system provides an experimental system to study the fate of pesticidal chemicals as well as the effects on microbial populations.

Rev Soc Bras Med Trop, 2000 Sep-Oct, 33(5), 417 - 25
{Epidemiology and ecology of dermatophytoses in the City of Fortaleza: Trichophyton tonsurans as important emerging pathogen of Tinea capitis}; Brilhante RS et al.; Dermatophytosis is the most common skin infectious disturbance in the world . In this research 2,297 patients were evaluated with suspected clinical lesions of dermatophytosis . It was observed that, 534 (23.2%) patients tested positive for dermatophytes . T . rubrum was the most prevalent specie (49.6%; p < or = 0.05), followed by T . tonsurans (34.4%), M . canis (7%) and T . mentagrophytes (6.2%) . When the species isolated was correlated with the respective anatomical localization, it was observed that T . tonsurans was the most frequent isolated in scalp lesions (73.9%; p < or = 0.01) . On the other hand, T . rubrum was the main specie involved in body lesions (72.8%; p < or = 0.05) . Therefore, in scalp infections it was observed that, there was an absolute prevalence of T . tonsurans . This evidence is different from the statistical data collected in the southeast and south of Brazil, as well as from other areas of the world, which still show M . canis as the most frequent microorganism isolated in Tinea capitis.

Nippon Ishinkin Gakkai Zasshi, 2000, 41(4), 235 - 9
{Recent knowledge allowing diagnosis and treatment of deep-seated trichosporonosis}; Yamakami Y et al.; Deep-seated trichosporonosis is a lethal opportunistic infection in immunocompromised patients . For the rapid diagnosis of this condition, we developed a novel nested-PCR assay that detects DNA specific for clinically important strains of Trichosporon in serum of patients with disseminated trichosporonosis . In this assay, two sets of oligonucleotide primers were derived from the sequence of 26 S ribosomal RNA genes of T . asahii . The specific fragment was amplified from T . asahii and T . mucoides but not from other microorganisms . In a retrospective study using serum samples of patients with disseminated trichosporonosis, the specific fragment was detected in 64% (7 of 11) . To treat this infection, we studied the efficacy of rhG-CSF alone and in combination with antifungal agents against disseminated trichosporonosis in neutropenic mice . The results suggested that rhG-CSF might be a useful immunomodulator against Trichosporon infections and the therapeutic outcome might be better when used in combination with antifungal agents.

Orthop Nurs, 2000 Mar-Apr, 19(2), 19 - 25; quiz 26-8
How drug-resistant microorganisms affect nursing; Glover TL; Although antibiotics have improved the mortality and morbidity associated with infectious disease, antibiotic mismanagement has created drug-resistant microorganisms, which are present in the environment outside the hospital . In the hospital, drug-resistant microorganisms require Contact Isolation, a transmission-based isolation recommended by the Centers for Disease Control and Prevention . The nurse's role in preventing the spread of drug-resistant microorganisms includes using appropriate infection control and isolation guidelines (especially handwashing), working with other health care workers to maintain appropriate infection control standards at all times, and teaching patients and families about infection control and antibiotic management.

J Antimicrob Chemother, 2000 Nov, 46(5), 685 - 93
In vitro inactivation of Chlamydia trachomatis and of a panel of DNA (HSV-2, CMV, adenovirus, BK virus) and RNA (RSV, enterovirus) viruses by the spermicide benzalkonium chloride; Belec L et al.; Kinetics of inactivation by the detergent spermicide benzalkonium chloride (BZK) of Chlamydia trachomatis and of a panel of DNA viruses {herpes simplex virus hominis type 2 (HSV-2), cytomegalovirus (CMV), adenovirus (ADV) and BK virus (BKV)} and RNA {respiratory syncytial virus (RSV) and enterovirus (ENV)} were established in accordance with a standardized in vitro protocol . After a 5 min incubation, inactivation of >95% of HSV-2 and CMV was obtained at a concentration of 0.0025% (w/v) (25 Ig/L); concentrations as low as 0.0005%, 0.0050% and 0.0125%, induced a 3.0 log10 reduction in infectivity of HSV-2 and CMV, RSV and ADV, respectively . After a 60 min incubation, concentrations of 0.0125% and 0.050% provided a 3.0 log10 reduction in infectivity of ENV and BKV, respectively . These features indicate that sensitivity to BZK was very high (HSV-2 and CMV) or high (RSV) for enveloped viruses, intermediate (ADV) or low (ENV and BKV) for non-enveloped viruses . Furthermore, BZK had marked antichlamydial activity, showing >99% killing after only a 1 min incubation at a concentration of 0.00125% . BZK demonstrates potent in vitro activity against the majority of microorganisms causing sexually transmitted infectious diseases, including those acting as major genital cofactors of human immunodeficiency virus transmission . These attributes qualify BZK as a particularly attractive candidate for microbicide development.

J Cardiovasc Nurs, 2000 Oct, 15(1), 13 - 26
Inflammation and infection in acute coronary syndrome; Albert NM; Basic science research has revealed that monocytes and macrophages are important factors in atherogenesis . Immune system activation occurs at all stages of plaque formation, from the fatty streak to an advanced, complicated lesion . The inflammatory response not only stimulates changes in coronary artery endothelial cells causing endothelial injury and dysfunction, but also plays a role in plaque instability and rupture . New perspectives of atherosclerosis and acute coronary syndromes will be discussed in relation to inflammation . In addition, discussion will focus on bacterial and viral infectious microorganisms as a potential factor that may induce and promote inflammation and lead to acute coronary events . Clinical studies in humans have provided insight relating inflammation and infectious agents to atherosclerosis and plaque vulnerability . Other studies focus on specific interventions that may aid in diagnosis and treatment.

Microbiol Res, 2000 Sep, 155(3), 179 - 95
Reliable amplification of actin genes facilitates deep-level phylogeny; Voigt K et al.; The gene for actin as a highly conserved and functionally essential genetic element is developing into a major tool for phylogenetic analysis within a broad organismic range . We therefore propose a set of universally applicable primers that allow reliable amplification of actin genes . For primer construction the amino acid sequences of 57 actin genes comprising fungi, animals, plants and protists were analysed, aligned and used for the definition of six well-conserved regions which are suitable as priming sites in PCR amplification experiments . Ten primers were designed for specific in vitro amplification of actin gene fragments from a wide range of microorganisms . The corresponding gene fragments provide a strong basis to isolate nearly complete actin genes for further molecular characterization and for establishing phylogenies based on actin gene trees.

Expert Opin Investig Drugs, 2000 Jun, 9(6), 1243 - 56
Microbial pathogens and apoptotic anticancer therapy; Pasechnik V; In spite of tremendous efforts to control cancer, the mortality associated with this disease has been increasing in developed countries in the recent decades . Inadequate efficiency of existing therapeutic regimens and the rise of multi-drug resistant cancer cells are the main factors which require a broadening of investigations into novel anticancer strategies . Enhancement of apoptosis in tumours has been suggested recently as a new anticancer strategy . It targets the disruption of equilibrium between cell proliferation and cell death in tumours and suggests to restore it through the use of pharmacological agents or genetic approaches . Apoptotic therapy has attracted many groups of investigators and several companies have entered the race to develop the first generation of apoptotic anticancer agents . The review discusses the role that pathogenic microorganisms may have as the source of agents for apoptotic therapy.

Rev Esp Cardiol, 2000 Oct, 53(10), 1384 - 96
{Practice guidelines of the Spanish Society of Cardiology on endocarditis}; Valles F et al.; Infectious endocarditis is a disease which mainly involves the cardiac valves . It has a bad prognosis and is caused by a great variety of microorganisms . Prophylaxis is important although the effectiveness and the best way to achieve it remain unclear . Recommendations are herein presented . The diagnosis is based on clinical, bacteriological, and echocardiographic findings mainly based on Duke's criteria . Transthoracic and transesophageal echography are not only of diagnostic value but are also a tool to determine the therapy to follow . Antibiotic therapy should be selected according to the organisms isolated and their in vitro susceptibility . Guidelines for empirical antibiotic therapy in cases of negative cultures are also included . Lastly, indications and time for surgery are discussed.

Biochim Biophys Acta, 2000 Oct 18, 1482(1-2), 272 - 83
Human neutrophil gelatinase-associated lipocalin and homologous proteins in rat and mouse; Kjeldsen L et al.; Neutrophil gelatinase-associated lipocalin (NGAL) is a 25-kDa lipocalin originally purified from human neutrophils . It exists in monomeric and homo- and heterodimeric forms, the latter as a dimer with human neutrophil gelatinase . It is secreted from specific granules of activated human neutrophils . Homologous proteins have been identified in mouse (24p3/uterocalin) and rat (alpha(2)-microglobulin-related protein/neu-related lipocalin) . Structural data have confirmed a typical lipocalin fold of NGAL with an eight-stranded beta-barrel, but with an unusually large cavity lined with more polar and positively charged amino acid residues than normally seen in lipocalins . Chemotactic formyl-peptides from bacteria have been proposed as ligands of NGAL, but binding experiments and the structure of NGAL do not support this hypothesis . Besides neutrophils, NGAL is expressed in most tissues normally exposed to microorganisms, and its synthesis is induced in epithelial cells during inflammation . This may indicate either a microbicidal activity of NGAL or a role in regulation of inflammation or cellular growth, putative functions yet to be demonstrated.

Crit Care Med, 2000 Oct, 28(10), 3412 - 6
Pharmacokinetics and dosing regimen of meropenem in critically ill patients receiving continuous venovenous hemofiltration; Ververs TF et al.; OBJECTIVE: To study the pharmacokinetics of meropenem in critically ill patients with acute renal failure receiving continuous venovenous hemofiltration (CWHF) . DESIGN: Prospective, open-labeled study . SETTING: Medical intensive care unit of the University Medical Center Utrecht . PATIENTS: Five critically ill patients receiving CWHF for acute renal failure treated with meropenem for documented or suspected bacterial infection . INTERVENTION: All patients received meropenem (500 mg) administered intravenously every 12 hrs . Plasma samples and ultrafiltrate aliquots were collected during one dosing interval . MEASUREMENTS AND RESULTS: Mean age and body weight of the patients studied were 46.6 yrs (range, 28-61 yrs) and 85.8 kg (range, 70-100 kg), respectively . The following pharmacokinetic variables for meropenem were obtained: mean peak plasma concentration was 24.5 +/- 7.2 mg/L, mean trough plasma concentration was 3.0 +/- 0.9 mg/L, mean terminal elimination half-life was 6.37 +/- 1.96 hrs, mean total plasma clearance was 4.57 +/- 0.89 L/hr, mean CWHF clearance was 1.03 +/- 0.42 L/hr, mean nonrenal clearance was 3.54 +/- 1.06 L/hr, and mean volume of distribution was 0.37 +/- 0.15 L/kg . CONCLUSION: In critically ill patients with acute renal failure, nonrenal clearance became the main elimination route . CWHF substantially contributed to the clearance of meropenem (23% of mean total plasma clearance) . We recommend meropenem to be dosed at 500 mg intravenously every 12 hrs in patients receiving CWHF, according to our operational characteristics . This dosing regimen resulted in adequate trough plasma levels for susceptible microorganisms.

Appl Environ Microbiol, 2000 Nov, 66(11), 4758 - 63
Identification of a universally primed-PCR-derived sequence-characterized amplified region marker for an antagonistic strain of Clonostachys rosea and development of a strain-specific PCR detection assay; Bulat SA et al.; We developed a PCR detection method that selectively recognizes a single biological control agent and demonstrated that universally primed PCR (UP-PCR) can identify strain-specific markers . Antagonistic strains of Clonostachys rosea (syn . Gliocladium roseum) were screened by UP-PCR, and a strain-specific marker was identified for strain GR5 . No significant sequence homology was found between this marker and any other sequences in the databases . Southern blot analysis of the PCR product revealed that the marker represented a single-copy sequence specific for strain GR5 . The marker was converted into a sequence-characterized amplified region (SCAR), and a specific PCR primer pair was designed . Eighty-two strains, isolated primarily from Danish soils, and 31 soil samples, originating from different localities, were tested, and this specificity was confirmed . Two strains responded to the SCAR primers under suboptimal PCR conditions, and the amplified sequences from these strains were similar, but not identical, to the GR5 marker . Soil assays in which total DNA was extracted from GR5-infested and noninoculated field soils showed that the SCAR primers could detect GR5 in a pool of mixed DNA and that no other soil microorganisms present contained sequences amplified by the primers . The assay developed will be useful for monitoring biological control agents released into natural field soil.

Appl Environ Microbiol, 2000 Nov, 66(11), 4625 - 33
Persistence of selected Spartina alterniflora rhizoplane diazotrophs exposed to natural and manipulated environmental variability; Bagwell CE et al.; Rhizoplane-rhizosphere nitrogen-fixing microorganisms (diazotrophs) are thought to provide a major source of biologically available nitrogen in salt marshes dominated by Spartina alterniflora . Compositional and functional stability has been demonstrated for this important functional group; however, the quantitative responses of specific diazotroph populations to environmental variability have not been assessed . Changes in the relative abundances of selected rhizoplane diazotrophs in response to long-term fertilization were monitored quantitatively by reverse sample genome probing . Fertilization stimulated Spartina, with plant height nearly tripling after 1 year . Fertilization also resulted in significant changes in interstitial porewater parameters . Diazotrophic activity (acetylene reduction assay) was sensitive to the fertilization treatments and was inhibited in some plots on several sampling dates . However, inhibition was never consistent across all of the replicates within a treatment and activity always recovered . The rhizoplane diazotrophs were quite responsive to environmental variability and to experimental treatments, but none were displaced by either environmental variability or experimental treatments . All strains were detected consistently throughout this study, and extensive spatial heterogeneity in the distribution patterns of these organisms was observed . The physiological traits that differentiate the diazotroph populations presumably support competitiveness and niche specialization, resulting in the observed resilience of the diazotroph populations in the rhizosphere.

Scand J Infect Dis, 2000, 32(5), 507 - 10
Mycobacterium tuberculosis drug resistance in Turkey, 1976-97; Bengisun JS et al.; Drug-resistant tuberculosis is increasing day by day and is a significant threat to tuberculosis control because there are few drugs effective against Mycobacterium tuberculosis . This study evaluates the resistance of the microorganism to primary anti-tuberculosis drugs over the 21-y period 1976-97 . Records from the bacteriology laboratory of the Department of Chest Diseases and Tuberculosis, Ankara University Medical Faculty were evaluated retrospectively . Among 3,418 mycobacteria strains, 3,319 (97.1%,) M . tuberculosis were isolated and their susceptibility was examined by the proportion method in Loewenstein-Jensen medium . It was found that 60.8% of isolated strains were susceptible, whereas 39.2%, were resistant to at least one drug . Multi-drug resistant tuberculosis (MDR-TB) was found in 194 (5.8%) materials . Over the 21-y period studied, total resistance to isoniazid (INH), rifampicin (RF) and streptomycin (SM) were determined as 10.5, 6.9 and 7.0%, respectively . It was also observed that the resistance rates to INH or SM increased, whereas resistance to RF was not changed within this period . While resistance to the 2-drug combination RF+SM increased, resistance to INH+SM decreased significantly . There was no change in resistance to the 2-drug INH + RF or 3-drug INH + RF + SM combinations in the same period . In conclusion, combined therapy is still useful and available for the treatment of resistant tuberculosis, and INH should be included in the chemotherapeutic regimen even if high resistance rates are shown to exist.

Exp Parasitol, 2000 Oct, 96(2), 75 - 88
Role of nonspecific cytotoxic cells in the induction of programmed cell death of pathogenic protozoans: participation of the Fas ligand-Fas receptor system; Jaso-Friedmann L et al.; Numerous different species of parasites and pathogenic microorganisms produce programmed cell death (PCD) and apoptosis in eukaryotic targets . How ever, only a few studies have demonstrated that effector cells, cytokines, growth factors, or soluble apoptosis-inducing factors are capable of initiating apoptosis in protozoan parasites . Certain Tetrahymena spp . in teleosts are opportunistic pathogens . In the present study these pathogenic protozoans were developed as a model system to describe the potential role of the Fas ligand (FasL)-Fas receptor (FasR) system as a means of innate immunity in teleosts . Nonspecific cytotoxic cells (NCC) constitutively express soluble FasL (sFasL) . Binding of the antigen receptor (i.e., NCCRP-1) on NCC to target cells caused the release of sFasL into the milieu . The presence of functional sFasL in these supernatants was determined by Western blot analysis and by demonstrating the lysis of FasR(+) HL-60 but not IM-9 (FasR(-)) targets . Soluble FasL containing supernatants generated by tumor cell-activated NCC also produced a reduction in 2 N DNA (i.e., DNA hypoploidy) of T . furgasoni . The induction of DNA hypoploidy by NCC supernatants could be neutralized by adsorption of the supernatants with anti-FasL antibody (but not with an isotype control) . Experiments were next done to determine the expression of FasR on Tetrahymena and study the effects of anti-FasR monoclonal crosslinkage and treatment with soluble human recombinant FasL (huFasL) on initiation of PCD in Tetrahymena . Cell cycle analysis revealed that both crosslinkage and soluble huFasL binding to Tetrahymena produced DNA hypoploidy . The reduction in diploid DNA was confirmed by observing oligonucleosome fragmentation (DNA laddering) following anti-FasR treatment . Additional evidence for FasR expression on Tetrahymena was obtained using fluorescence microscopy and flow cytometry . Both methods showed that all Tetrahymena examined (three species consisting of four isolates) expressed membrane FasR . These studies demonstrated the potential of the FasL-FasR system in teleosts for initiation of antiparasite innate immunity . Effector NCC may initiate PCD of Tetrahymena that express a FasR-like protein . Induction of apoptosis may be a major mechanism of homeostatic control of protozoan parasite infestations/infections .

J Agric Food Chem, 2000 Oct, 48(10), 4835 - 8
Identification and quantification of geosmin, an earthy odorant contaminating wines; Darriet P et al.; Musty, earthy odors are highly detrimental to the aromatic quality of wines . A characteristic aroma of freshly tilled earth, damp cellar was studied in some red and white wines of different origins . The extraction and purification of the wines marked by this odor have shown after analysis by gas chromatography-olfactometry a unique strong odorous zone having the same odor as the one perceived at tasting . The compound responsible for this odorous zone was identified by gas chromatography-mass spectrometry as geosmin (trans-1,10-dimethyl-trans-9-decalol), which possesses a distinctive earthy odor . Geosmin may be present in wines at levels higher than the racemic geosmin olfactory perception threshold, thus suggesting its contribution to their off-aroma . Moreover, the presence of this compound in juice taken from freshly crushed grapes suggests that microorganisms that develop on the grapes may contribute to the presence of this compound in wines.

J Agric Food Chem, 2000 Oct, 48(10), 4681 - 6
Influence of metam sodium on the dissipation and residual biological activity of the herbicides EPTC and pebulate in surface soil under black plastic mulch; Stiles CL et al.; Metam sodium is a potential replacement for methyl bromide, which is used to control soil pests . Metam sodium rapidly breaks down in the soil to form methylisothiocyanate (MITC) . Dissipation of the herbicides EPTC and pebulate in a silt loam soil under plastic mulch in the absence and presence of metam sodium was examined in field experiments in 1998 and 1999 at Knoxville, Tennessee . EPTC half-life (DT(50)) was 9 d, but when applied in conjunction with metam sodium DT(50) increased to 22 d . Similarly, average pebulate DT(50) was 8 d and increased to 23 d when applied in conjunction with metam sodium . This increase in herbicide DT(50) with the addition of metam sodium is thought to be due to a reduction in soil microorganisms that degrade EPTC and pebulate . EPTC applied with metam sodium injured tomato plants and reduced total crop yield more than EPTC, pebulate, or pebulate with metam sodium . The increased tomato injury may have been related to the greater and prolonged activity of EPTC and slower EPTC dissipation in the presence of metam sodium or MITC.

J Agric Food Chem, 2000 Oct, 48(10), 4597 - 605
Effects of pulsed electric fields on the quality of orange juice and comparison with heat pasteurization; Yeom HW et al.; Effects of pulsed electric fields (PEF) at 35 kV/cm for 59 micros on the quality of orange juice were investigated and compared with those of heat pasteurization at 94.6 degrees C for 30 s . The PEF treatment prevented the growth of microorganisms at 4, 22, and 37 degrees C for 112 days and inactivated 88% of pectin methyl esterase (PME) activity . The PEF-treated orange juice retained greater amounts of vitamin C and the five representative flavor compounds than the heat-pasteurized orange juice during storage at 4 degrees C (p < 0.05) . The PEF-treated orange juice had lower browning index, higher whiteness (L), and higher hue angle (theta) values than the heat-pasteurized orange juice during storage at 4 degrees C (p < 0 . 05) . The PEF-treated orange juice had a smaller particle size than the heat-pasteurized orange juice (p < 0.05) . degrees Brix and pH values were not significantly affected by processing methods (p > 0 . 05).

Crit Rev Microbiol, 2000, 26(3), 147 - 62
Cork taint in wine: scientific knowledge and public perception: a critical review; Silva Pereira C et al.; The manufacturing process of cork stoppers includes a stabilization period of the cork slabs, following boiling, during which mold growth completely covers the cork slabs . This process has been used traditionally for several decades; however, due to the possibility of certain molds isolated from cork to produce off flavor compounds, especially 2,4,6-trichloroanisole and 2,3,4,6-tetrachloroanisole, recently cork stoppers are being unsoundly targeted with the accusation of inducing cork taint in wine . This article reviews the manufacturing process of cork stoppers, the diversity of microorganisms associated with cork, and finally the diversity and origins of the compounds associated with cork taint in wine, focusing on those currently considered as more important . Some important results recently obtained by the authors are also included . The current idea of suppressing mold growth during cork stopper manufacturing is discussed, as well as the erroneous idea of imputing, directly and exclusively, to cork the responsibility of the so-called cork taint in wine.

Pediatr Infect Dis J, 2000 Oct, 19(10 Suppl), S123 - 4
Overview of Lysol scientific studies; Rubino JR; When followed, simple hygienic practices such as handwashing and surface disinfection along with proper food handling techniques can have a positive impact on the health of families and individuals in nonmedical settings like homes, day care and long term care facilities . Several studies have attempted to identify the specific role surface disinfectants can play in this effort . The evidence seems to indicate that these types of products, when properly used, can be beneficial . Because it has been established that environmental surfaces act as intermediates in the transmission of microorganisms throughout the day-care center and in homes, future studies should be developed to quantitate the impact of specific interventions in the reduction of microorganisms.

Risk Anal, 2000 Aug, 20(4), 513 - 20
The Beta Poisson dose-response model is not a single-hit model; Teunis PF et al.; The choice of a dose-response model is decisive for the outcome of quantitative risk assessment . Single-hit models have played a prominent role in dose-response assessment for pathogenic microorganisms, since their introduction . Hit theory models are based on a few simple concepts that are attractive for their clarity and plausibility . These models, in particular the Beta Poisson model, are used for extrapolation of experimental dose-response data to low doses, as are often present in drinking water or food products . Unfortunately, the Beta Poisson model, as it is used throughout the microbial risk literature, is an approximation whose validity is not widely known . The exact functional relation is numerically complex, especially for use in optimization or uncertainty analysis . Here it is shown that although the discrepancy between the Beta Poisson formula and the exact function is not very large for many data sets, the differences are greatest at low doses--the region of interest for many risk applications . Errors may become very large, however, in the results of uncertainty analysis, or when the data contain little low-dose information . One striking property of the exact single-hit model is that it has a maximum risk curve, limiting the upper confidence level of the dose-response relation . This is due to the fact that the risk cannot exceed the probability of exposure, a property that is not retained in the Beta Poisson approximation . This maximum possible response curve is important for uncertainty analysis, and for risk assessment of pathogens with unknown properties.

J Immunol, 2000 Nov 1, 165(9), 5186 - 91
Nonopsonic phagocytosis of Mycobacterium kansasii by human neutrophils depends on cholesterol and is mediated by CR3 associated with glycosylphosphatidylinositol-anchored proteins; Peyron P et al.; Receptors involved in the phagocytosis of microorganisms under nonopsonic conditions have been little studied in neutrophils . Complement receptor type 3 (CR3) is a pattern recognition receptor able to internalize zymosan and C3bi-coated particles . We report that Abs directed against CR3 strongly inhibited nonopsonic phagocytosis of Mycobacterium kansasii in human neutrophils . In these cells CR3 has been found associated with several GPI-anchored proteins localized in cholesterol-rich microdomains (rafts) of the plasma membrane . Cholesterol sequestration by nystatin, filipin, or beta-cyclodextrin as well as treatment of neutrophils with phosphatidylinositol phospholipase C to remove GPI-anchored proteins from the cell surface markedly inhibited phagocytosis of M . kansasii, without affecting phagocytosis of zymosan or serum-opsonized M . kansasii . Abs directed against several GPI-anchored proteins inhibited phagocytosis of M . kansasii, but not of zymosan . N:-acetyl-D-glucosamine, which is known to disrupt interactions between CR3 and GPI proteins, also strongly diminished phagocytosis of these mycobacteria . In conclusion, phagocytosis of M . kansasii involved CR3, GPI-anchored receptors, and cholesterol . In contrast, phagocytosis of zymosan or opsonized particles involved CR3, but not cholesterol or GPI proteins . We propose that CR3, when associated with a GPI protein, relocates in cholesterol-rich domains where M . kansasii are internalized . When CR3 is not associated with a GPI protein, it remains outside of these domains and mediates phagocytosis of zymosan and opsonized particles, but not of M . kansasii.

Int J Med Microbiol, 2000 May, 290(2), 191 - 201
Target-based drug discovery for the development of novel antiinfectives; Selzer PM et al.; In the 20th century and especially during the last 50 years, antiinfectives have been increasingly used to control and prevent infectious diseases . Unfortunately the resistance of microorganisms to these pharmaceuticals has increased as well . At the same time the discovery process for novel antiinfectives, the so-called "conventional" screening approach, involves testing natural products or derivatives of known compounds in in vitro cultures . By now it is obvious that this screening approach did not meet the expectations to generate a sufficient number of novel drug candidates . Consequently, studies for selective antiinfectives with new modes of action, which are able to break resistance, are highly desirable for human and animal health . The enormous advance in sequencing technologies--leading to a constantly growing number of known microbial genomes--together with the rapid development of computer power and bioinformatic software tools, now makes it possible to identify genes and gene products that are essential to the pathogenic organisms and are therefore considered to be novel targets for the development of new antiinfectives . When these potential targets have been validated by sophisticated laboratory methods, large diverse compound libraries can be tested in in vitro assays using high-throughput screening . This approach will most likely generate an increasing number of novel lead structures that will be specifically optimized by modern combinatorial chemistry and subsequently lead to new antiinfective candidates strengthening the armoury of weapons available to fight infectious diseases in humans and animals.

Protein Sci, 2000 Sep, 9(9), 1607 - 17
Collectin structure: a review; Hakansson K et al.; Collectins are animal calcium dependent lectins that target the carbohydrate structures on invading pathogens, resulting in the agglutination and enhanced clearance of the microorganism . These proteins form trimers that may assemble into larger oligomers . Each polypeptide chain consists of four regions: a relatively short N-terminal region, a collagen like region, an alpha-helical coiled-coil, and the lectin domain . Only primary structure data are available for the N-terminal region, while the most important features of the collagen-like region can be derived from its homology with collagen . The structures of the alpha-helical coiled-coil and the lectin domain are known from crystallographic studies of mannan binding protein (MBP) and lung surfactant protein D (SP-D) . Carbohydrate binding has been structurally characterized in several complexes between MBP and carbohydrate; all indicate that the major interaction between carbohydrate and collectin is the binding of two adjacent carbohydrate hydroxyl group to a collectin calcium ion . In addition, these hydroxyl groups hydrogen bond to some of the calcium amino acid ligands . While each collectin trimer contains three such carbohydrate binding sites, deviation from the overall threefold symmetry has been demonstrated for SP-D, which may influence its binding properties . The protein surface between the three binding sites is positively charged in both MBP and SP-D.

J Microbiol Immunol Infect, 2000 Sep, 33(3), 165 - 8
Evaluation of different blood culture media in neonatal sepsis; Lee CS et al.; Blood drawn from neonatal patients is available in only limited amounts for blood cultures . The BACTEC Pediatrics (PEDS) Plus aerobic nonradiometric blood culture bottle was designed to aid the diagnosis of pediatric bacteremia . To assess the value of PEDS Plus blood culture medium for neonatal patients, we prospectively compared the PEDS Plus blood culture medium with the standard BACTEC aerobic medium (NR6A) . From January to December 1999, 192 pairs of PEDS Plus and NR6A blood culture bottles were collected by the pediatric microbiology laboratory of Taipei Veterans General Hospital . Seventeen (8.85%) isolates were considered to be clinically significant microorganisms . Isolation rate of the PEDS Plus culture bottles was significantly higher than that of the NR6A culture bottles (p < 0.001) . Six isolates were detected at least 1 day earlier by using the PEDS Plus culture bottles (p < 0.001) . Among those patients who were under antibiotic therapy, the PEDS Plus culture bottle showed more significant growth than the NR6A culture bottle (p < 0.001) . After weighing their benefits, we suggest substituting PEDS Plus bottles for NR6A bottles when culturing blood from neonatal patients or from those who are receiving antibiotic therapy.

Immunol Rev, 2000 Aug, 176, 154 - 70
B-cell activation by T-cell-independent type 2 antigens as an integral part of the humoral immune response to pathogenic microorganisms; Vos Q et al.; Antigens that are expressed on the surface of pathogens in an organized, highly repetitive form can activate specific B cells by cross-linking of antigen receptors in a multivalent fashion . B cells respond to these multivalent antigens in the absence of MHC class II-restricted T-cell help by a mechanism that depends on the expression of a functional Bruton's tyrosine kinase (Btk) . Accordingly, this class of immunogens has been designated T-cell-independent type 2 (TI-2) antigens . The unique properties of the B-cell response to TI-2 antigens are critically dependent on the formation of a small number of antigen receptor clusters, each of which contains approximately 10 to 20 antigen-bound membrane Ig (mIg) molecules . These clusters induce local membrane association of multiple activated Btk molecules, which results in long-term mobilization of intracellular ionized calcium . Such persistent calcium fluxes efficiently recruit transcription factors and thereby induce T-cell-independent B-cell activation and proliferation . While this first signal of multivalent mIg cross-linking can induce B-cell proliferation, we propose that a second signal is required for a TI-2 Ig secretory response . We have found that engagement of members of the Toll-like receptor (TLR) family could provide second signals that selectively induce Ig secretion in B cells that were activated by multivalent, but not by bivalent, antigen receptor engagement . This finding demonstrates a general mechanism by which TLRs recognize molecular motifs on the surface of pathogens and provide the TI-2-activated B cell with a second signal . In addition, TLR-dependent recognition of these non-self motifs by cells of the innate immune system can induce these cells to provide alternative and/or additional second signals in the TI-2 response . The complement system provides another link between the B cell and the innate immune system, and facilitates the mIg signal transduction by recruitment of CD21 in the immune response . Thus, the TI-2 response provides the host with a combination of "the best of both worlds": the recruitment of the fine specificity of the adaptive immune response and the utilization of both the speed of the innate immune system and the wealth of cytokines produced by its member cells upon stimulation by pathogenic organisms or their products . By combining these two pathways, the TI-2 response enables the host to rapidly produce antigen-specific Ig effector molecules that can be secreted at a sufficient rate to keep up with the rapid multiplication of invading infectious microorganisms, and will also prevent the intracellular spreading of a significant part of this population.

J Am Dent Assoc, 2000 Oct, 131(10), 1427 - 41
The dental unit waterline controversy: defusing the myths, defining the solutions; Mills SE; BACKGROUND AND OVERVIEW: This article reviews the literature on the subject of dental unit waterline contamination . It has been expanded from the text of a lecture given at the Scientific Frontiers in Dentistry program sponsored by the National Institute for Dental and Craniofacial Research in Bethesda, Md., in July 1999 . The author examines the underlying biological causes of waterline colonization by microorganisms, the evidence of potential health consequences and possible means of improving the quality of dental water . He also describes examples of devices currently marketed to improve and maintain the quality of dental treatment water . CONCLUSIONS: Microorganisms colonize dental units and contaminate dental treatment water . While documented instances of related illness are few, water that does not meet potable-water standards is inappropriate for use in dentistry . CLINICAL IMPLICATIONS: Exposure to water containing high numbers of bacteria violates basic principles of clinical infection control . Dentists should consider available options for improving the quality of water used in dental treatment.

Izv Akad Nauk Ser Biol, 2000 Sep-Oct, (5), 607 - 16
{Environmental activity of earthworms (Lumbricus terrestris L.) and the spatial organization of soil communities}; Tiunov AV et al.; The effect of feeding and burrowing activities of anecic earthworms (Lumbricus terrestris) on abiotic characteristics of the soil, biomass and activity of soil microorganisms, and the spatial distribution of Collembola and Lumbricidae species was studied in a Iinden forest near Moscow . The results showed that organic carbon content, nitrogen content, pH, and microbial biomass and basal respiration are considerably higher around L . terrestris burrows than in the surrounding soil . The total density of springtails near the burrows was 1.6-1.7 as high as at the control sites . The most pronounced preference for earthworm burrows was observed in the species dominating in the soils of undisturbed deciduous forests (Isotomiella minor and Isotoma notabilis) . The number and biomass of epigeic and endogeic earthworms also increased significantly in the zone of L . terrestris burrows . However, some springtail (Isotoma viridis, Protaphorura cf . nemorata, Lepidocyrtus lignorum) and earthworm species (Aporrectodea rosea) did not accumulate near L . terrestris burrows and even avoided them . Thus, L . terrestris activities create a mosaic of soil microhabitats, which provides for the coexistence of different microcommunities of soil organisms.

Curr Opin Struct Biol, 2000 Oct, 10(5), 536 - 41
Large-scale production of oligosaccharides using engineered bacteria; Endo T et al.; Rapid advances in the cloning and expression of glycosyltransferase genes, especially from bacteria, could open the way to overcoming difficulties in the mass production of oligosaccharides . The large-scale production of oligosaccharides using either glycosyltransferases isolated from engineered microorganisms or whole cells as an enzyme source could promote a new era in the field of carbohydrate synthesis.

J Food Prot, 2000 Oct, 63(10), 1447 - 9
Comparison of different peptidase substrates for evaluation of microbial quality of aerobically stored meats; Stepaniak L; Different aminopeptidase and endopeptidase substrates were assessed for the detection of enzymatic activity of microorganisms collected from the surface of aerobically cold-stored pork and beef . The most sensitive substrates were fluorogenic Ala-7-amino-4-methylcoumarin (Ala-AMC) or Leu-AMC and colorogenic Ala-p-nitroanilide (Ala-pNA) . Activity on natural oligopeptides, e.g., bradykinin or alpha(s1) casein fragment 1 to 23, was very low . The correlation coefficient (r) between log surface counts of 66 meat samples and log fluorescence or absorbance after incubation of surface microbial cells for 2 h with Ala-AMC, Leu-AMC, and Ala-pNA was 0.89, 0.83, and 0.82, respectively . A distinct yellow color was obtained with Ala-pNA when the surface count was approximately 10(6) CFU/cm2 . Although correlation and sensitivity was better, no clear advantage is obtained with the use of the fluorogenic Ala-AMC or Leu-AMC instead of Ala-pNA, a substrate proposed by Alvarado et al . (J . Food Sci . 57:1330, 1992) for rapidly assessing the microbial quality of refrigerated meat . The correlation coefficient (r) between time of cold storage and surface count was 0.69.

J Food Prot, 2000 Oct, 63(10), 1377 - 80
Heat resistance of Alicyclobacillus acidocaldarius in water, various buffers, and orange juice; Palop A et al.; The effect of the pH or the composition of the heating medium and of the sporulation temperature on the heat resistance of spores of a thermoacidophilic spore-forming microorganism isolated from a dairy beverage containing orange fruit concentrate was investigated . The species was identified as Alicyclobacillus acidocaldarius . The spores showed the same heat resistance in citrate-phosphate buffers of pH 4 and 7, in distilled water, and in orange juice at any of the temperatures tested (D120 degrees C = 0.1 min and z = 7 degrees C) . A raise in 20 degrees C in the sporulation temperature (from 45 to 65 degrees C) increased the heat resistance eightfold (from D110 degrees C = 0.48 min when sporulated at 45 degrees C to 3.9 min when sporulated at 65 degrees C) . The z-values remained constant for all sporulation temperatures . The spores of this strain of A . acidocaldarius were very heat resistant and could easily survive any heat treatment currently applied to pasteurize fruit juices.

J Clin Pathol, 2000 Sep, 53(9), 647 - 54
Microorganisms in the aetiology of atherosclerosis; Morre SA et al.; Recent publications have suggested that infective pathogens might play an important role in the pathogenesis of atherosclerosis . This review focuses on these microorganisms in the process of atherosclerosis . The results of in vitro studies, animal studies, tissue studies, and serological studies will be summarised, followed by an overall conclusion concerning the strength of the association of the microorganism with the pathogenesis of atherosclerosis . The role of the bacteria Chlamydia pneumoniae and Helicobacter pylori, and the viruses human immunodeficiency virus, coxsackie B virus, cytomegalovirus, Epstein-Barr virus, herpes simplex virus, and measles virus will be discussed.

J Surg Res, 2000 Nov, 94(1), 6 - 12
Usefulness of an alcohol solution of N-duopropenide for the surgical antisepsis of the hands compared with handwashing with iodine-povidone and chlorhexidine: clinical essay; Herruzo-Cabrera R et al.; BACKGROUND: The usual surgical antisepsis involves scrubbing the skin with antiseptic solutions . This procedure can damage the skin, with the subsequent risk of infection for the patient . There are several efficient and quick-acting antiseptic alcohol solutions that require no scrubbing . MATERIAL AND METHODS: We compare four alcohol solutions with the classic surgical handwashing products (chlorhexidine and iodine-povidone), in both in vitro (pigskin germ carriers) and in vivo studies . The latter (clinical essays) were done with healthy volunteers (crossed design) as well as with 154 surgical team members (Plastic Surgery or Traumatology), whose hand microbial flora were measured before and after scrubbing up and after surgery . RESULTS AND DISCUSSION: Because of its efficiency in the germ carrier, we chose a solution of N-duopropenide in 60 degrees alcohol with emollients for further comparison with the standard surgical scrub: 4% chlorhexidine and 7.5% iodine-povidone . The quantitative, semiquantitative, and qualitative results obtained with N-duopropenide without scrubbing were better in the healthy volunteers and surgical teams . This product reduced hand microorganisms by more than 2 log, and maintained the reduction for the entire study period . Four percent chlorhexidine initially reduced colonization more than 2 log but lost part of its effect over time during the surgical intervention . Last, 7.5% iodine-povidone reduced the germs by 1 log but at the end of surgery there were even more germs than before washing . CONCLUSION: Because of its efficacy, persistent effect, and skin protection, we advise that scrubbing with classic antiseptic solutions be replaced with gentle washing with an alcohol solution such as N-duopropenide in alcohol .

Eur J Oral Sci, 2000 Oct, 108(5), 412 - 7
Dental plaque mass and acid production activity of the microbiota on teeth; Borgstrom MK et al.; With the purpose of elucidating the effect of dental plaque thickness on the acid production activity in dental plaque, we studied the prevalence of acid anions in dental plaque of children harbouring different amount of plaque on their teeth . On two occasions, the occurrence of plaque on the dentition was scored (Silness-Loe's index), and plaque on available smooth surfaces was collected and the wet weight determined . On the first occasion, the amount of acid anions in resting plaque, and on the second occasion, the acid anions of sucrose-exposed plaque were analysed with isotachophoresis . Mean value of plaque wet weights per individual dentition was 11.7 +/- 9.0 mg (first occasion) and 11.1 +/- 8.9 mg (second occasion) . Dominating anions in resting plaque were acetate < propionate < lactate and in sucrose-exposed plaque lactate < acetate < propionate . The microbial acid production activity (acid anion per mg wet plaque weight) decreased with increasing weights of the plaque mass . The findings illustrate the cellular glycolytic metabolism of plaque microorganisms in thin and thick plaque, being a consequence of the diverse environmental condition existing in these ecosystems.

Res Microbiol, 2000 Sep, 151(7), 513 - 9
New insights into symbiotic associations between ants and bacteria; Boursaux-Eude C et al.; Many ants live in complex mutualistic or parasitic relationships with other insects or plants, some of which are classical examples of the mutual benefit of symbiosis . However, only in the past few years have new insights into the symbiosis of ants and microorganisms been reported . Examples are the symbiosis of ants of the genus Camponotus with intracellular bacteria present in their midgut, and the tripartite relationship of ants of the tribe Attini with an extracellular bacterium essential for the cultivation of their fungus gardens . The analysis of the parasitic and mutualistic interactions of these organisms will allow interesting insights into the evolution of symbiosis and possibly lead to novel strategies of pest control.

Dtsch Tierarztl Wochenschr, 2000 Aug, 107(8), 302 - 4
{Rules to control ddrinking water supply systems in livestock farming}; Hartung J; Water is regarded as one of the most important distributors of infectious diseases . Moreover it can carry chemical compounds and toxic substances . Presently there are no specific legal regulations which define the quality of the drinking water for animals in Germany . However, some rules and criteria exist which help to survey and secure the water supply of animals on farm level . When controlling the hygienic quality of water on the farm it is necessary to investigate not only the water itself but also the local facilities around the water well . If health problems occur in the stock the water tanks, the tubing system which distributes the water in the animal houses and the drinkers have to be checked carefully . Water samples for the analysis on microorganisms and chemical contaminants should be taken according to a strict protocol . The regulations of the German drinking water directive for humans can be used as an orientation to characterise the drinking water quality for the animals . Nevertheless it seems useful to elaborate animal species specific thresholds for water contaminants particularly for food producing animals . A proposal for some threshold values is reported.

Adv Biochem Eng Biotechnol, 2000, 69, 41 - 70
Development of applied microbiology to modern biotechnology in Japan; Beppu T; Development of modern biotechnology in Japan is characterized by unique contributions from applied microbiology and bioindustry . This review tries to summarize these original contributions with special emphasis on industrial production of useful substances by microorganisms . In the first part, development of applied microbiology and bioindustry in the last half of the twentieth century is summarized with a brief overview of the traditional background . In the second part, recent progress is reviewed with citation of typical achievements in biotechnology, applied enzymology, secondary metabolites, genetic engineering, and screening of microbial diversity, respectively.

Am J Obstet Gynecol, 2000 Oct, 183(4), 914 - 20
Evidence for the participation of interstitial collagenase (matrix metalloproteinase 1) in preterm premature rupture of membranes; Maymon E et al.; OBJECTIVE: Rupture of membranes is thought to result from the effects of physical forces in localized areas of the membranes weakened by the degradation of structural collagens . Matrix metalloproteinases are enzymes that degrade extracellular matrix components and have been implicated in membrane rupture . The objective of this study was to determine whether spontaneous rupture of membranes is associated with a change in the amniotic fluid concentration of interstitial collagenase (matrix metalloproteinase 1 {MMP-1}), a major collagenase . STUDY DESIGN: A cross-sectional study was conducted to determine MMP-1 concentrations in amniotic fluid from 353 women in the following categories: (1) term with intact membranes not in labor and in labor, (2) preterm labor who delivered at term, (3) preterm labor who delivered preterm without microbial invasion of the amniotic cavity, (4) preterm labor who delivered preterm with microbial invasion of the amniotic cavity, (5) preterm premature rupture of membranes with and without microbial invasion of the amniotic cavity, (6) term premature rupture of membranes not in labor and in labor, and (7) mid trimester of pregnancy . Microbial invasion of the amniotic cavity was determined by an amniotic fluid culture positive for microorganisms . MMP-1 concentrations in amniotic fluid were determined by means of sensitive and specific immunoassays . RESULTS: (1) MMP-1 was detectable in 81.3% of amniotic fluid samples (287/353), and its concentrations increased with advancing gestational age (r = 0.4; P <.001) . (2) Preterm premature rupture of membranes was associated with a significant increase in the median amniotic fluid concentration of MMP-1 (P =.02) . (3) Women with term premature rupture of membranes had a significantly lower amniotic fluid MMP-1 concentration than those with intact membranes at term not in labor (P <.001) . (4) Microbial invasion of the amniotic cavity in patients in preterm labor with intact membranes and in patients with preterm premature rupture of membranes was also associated with significant increases in the median amniotic fluid MMP-1 concentrations (P <.05 and P <.01, respectively) . (5) Patients with preterm premature rupture of membranes and microbial invasion of the amniotic cavity had a significantly higher median amniotic fluid MMP-1 concentration than those with intact membranes and microbial invasion of the amniotic cavity (P =.01) . (6) Neither term nor preterm parturition was associated with changes in amniotic fluid MMP-1 concentrations (P =.6 and P =.3, respectively) . CONCLUSION: (1) Collagenase 1 (MMP-1) is a physiologic constituent of amniotic fluid . (2) Preterm premature rupture of membranes (in both the presence and absence of infection) was associated with an increase in the amniotic fluid MMP-1 concentrations . (3) Neither term nor preterm parturition was associated with a significant increase in the amniotic fluid concentration of MMP-1.

FEMS Microbiol Lett, 2000 Sep 15, 190(2), 215 - 21
Characterization of strain HY99, a novel microorganism capable of aerobic and anaerobic degradation of aniline; Kahng HY et al.; We have characterized a novel microorganism, strain HY99, which is capable of aerobic and anaerobic degradation of aniline . Strain HY99 was found to aerobically metabolize aniline via catechol and 2-hydroxymuconic semialdehyde intermediates, and to transform aniline via p-aminobenzoate in anaerobic environments . Physiological and biochemical tests revealed that strain HY99 was most similar to Delftia acidovorans, but unlike D . acidovorans, strain HY99 was able to metabolize aniline under anaerobic conditions linked with nitrate reduction . Phylogenetic analysis based on 16S rDNA sequencing also revealed that strain HY99 was closely related to D . acidovorans, with 96% overall similarity.

Nature, 2000 Oct 5, 407(6804), 651 - 4
The large-scale organization of metabolic networks; Jeong H et al.; In a cell or microorganism, the processes that generate mass, energy, information transfer and cell-fate specification are seamlessly integrated through a complex network of cellular constituents and reactions . However, despite the key role of these networks in sustaining cellular functions, their large-scale structure is essentially unknown . Here we present a systematic comparative mathematical analysis of the metabolic networks of 43 organisms representing all three domains of life . We show that, despite significant variation in their individual constituents and pathways, these metabolic networks have the same topological scaling properties and show striking similarities to the inherent organization of complex non-biological systems . This may indicate that metabolic organization is not only identical for all living organisms, but also complies with the design principles of robust and error-tolerant scale-free networks, and may represent a common blueprint for the large-scale organization of interactions among all cellular constituents.

Nature, 2000 Oct 5, 407(6804), 623 - 6
A marine microbial consortium apparently mediating anaerobic oxidation of methane; Boetius A et al.; A large fraction of globally produced methane is converted to CO2 by anaerobic oxidation in marine sediments . Strong geochemical evidence for net methane consumption in anoxic sediments is based on methane profiles, radiotracer experiments and stable carbon isotope data . But the elusive microorganisms mediating this reaction have not yet been isolated, and the pathway of anaerobic oxidation of methane is insufficiently understood . Recent data suggest that certain archaea reverse the process of methanogenesis by interaction with sulphate-reducing bacteria . Here we provide microscopic evidence for a structured consortium of archaea and sulphate-reducing bacteria, which we identified by fluorescence in situ hybridization using specific 16S rRNA-targeted oligonucleotide probes . In this example of a structured archaeal-bacterial symbiosis, the archaea grow in dense aggregates of about 100 cells and are surrounded by sulphate-reducing bacteria . These aggregates were abundant in gas-hydrate-rich sediments with extremely high rates of methane-based sulphate reduction, and apparently mediate anaerobic oxidation of methane.

Semin Neonatol, 2000 Nov, 5(4), 273 - 80
The epidermal barrier; Cartlidge P; A mature epidermis is an effective barrier which prevents dehydration from the loss of body water, poisoning from the absorption of noxious substances, and systemic infection from invading surface microorganisms . The epidermal barrier resides within the most superficial layer of the skin, the stratum corneum . In utero the fetus has no need for a skin barrier, so the stratum corneum does not start to develop until around 24 weeks' gestation . After 24 weeks there is a steady increase in the number of epidermal cell layers and in epidermal thickness, although it is not until around 34 weeks' gestation that a well-defined stratum corneum has completely developed . A weak epidermal barrier is, therefore, present is very preterm infants (<30 weeks' gestation) during the first 2-3 weeks of life and if the skin is damaged by trauma or disease .

Annu Rev Cell Dev Biol, 2000, 16, 301 - 32
Epithelial M cells: differentiation and function; Kraehenbuhl JP et al.; M cells are distinctive epithelial cells that occur only in the follicle-associated epithelia that overlie organized mucosa-associated lymphoid tissues . They are structurally and functionally specialized for transepithelial transport, delivering foreign antigens and microorganisms to organized lymphoid tissues within the mucosae of the small and large intestines, tonsils and adenoids, and airways . M cell transport is a double-edged sword: Certain pathogens exploit the features of M cells that are intended to promote uptake for the purpose of immunological sampling . Eludication of the molecular architecture of M cell apical surfaces is important for understanding the strategies that pathogens use to exploit this pathway and for utilizing M cell transport for delivery of vaccines to the mucosal immune system . This article reviews the functional and biochemical features that distinguish M cells from other intestinal cell types . In addition it synthesizes the available information on development and differentiation of organized lymphoid tissues and the specialized epithelium associated with these immune inductive sites.

Allergy, 2000 Oct, 55(10), 916 - 22
The initial care of newborn infants and subsequent hay fever; Montgomery SM et al.; BACKGROUND: Patterns of neonatal exposure to microorganisms have changed substantially over the last 100 years, and it has been suggested that this has influenced the risk of immune-mediated disease . Using a proxy measure, we tested the hypothesis that the initial handling of newborn infants, which is known to affect the pattern of exposure to microorganisms, may alter the risk of developing subsequent atopy, as indicated by hay fever . METHODS: Analysis was performed on 5,519 members of the 1970 British Cohort Study, a nationally representative birth cohort . Cohort members with hay fever were identified at intervals up to the age of 26 years . Details of neonatal care and childhood circumstances were recorded prospectively . Those who had spent their first night away from their mother in the communal infant nursery were selected as likely to have experienced atypical exposure compared with infants who remained with their mother . Adjustment was made for potential confounding factors in infancy and childhood by multiple logistic regression analysis . RESULTS: Unadjusted relative odds (with 95% CI) for developing hay fever among those spending the first night in the communal nursery, when compared with other infants who remained with the mother, were 1.48 (1.23-1.77), P<0.001 . Comprehensive adjustment for the potential confounding factors, including feeding practices on the first day of life, markers of social and material circumstances, and region, did not substantially alter this relationship, with adjusted relative odds of 1.31 (1.08-1.59), P=0.005 . CONCLUSIONS: While our proxy measure is associated with an increased risk of hay fever, further research is required to confirm that this is due to the pattern of infectious exposure in very early life . The results are consistent with the hypothesis that the first challenges are particularly important in the development of the newborn infant's immune system.

Prog Retin Eye Res, 2000 Nov, 19(6), 649 - 68
Towards a closed eye model of the pre-ocular tear layer; Sack RA et al.; Although the tear film has been extensively studied as it exists in the open eye state, until recently very little was known as to what happens to the tear film on eye closure . Recent studies have shown that eye closure results in a profound change in the composition, origins, turnover and physiological functions of the tear film . These changes include a shift from an inducible, neurologically controlled, lacrimal secretion containing among other proteins primarily lysozyme, lactoferrin and tear specific lipocalin, to a much slower, constitutive-type of secretion, composed almost exclusively of sIgA . This change is accompanied by the build-up of sialoglycoproteins of epithelial and goblet cell origin, the build-up and activation of complement and the build-up of serum proteins . In addition, various cytokines and proinflammatory mediators accumulate, including some which are potent inducers of angiogenesis and leukochemotaxis . The closed eye also exhibits the recruitment and activation of massive numbers of PMN cells . This results in a stagnant, closed eye layer, which is extremely rich in reactive complement products, PMN cell proteases including protease-3, elastase, capthepsin G, MMP-9 and urokinase . We have postulated that this shift represents a fundamental change in host-defense strategies from a passive-barrier defense to an active immune, inflammatory, phagocyte-mediated process and that this shift is necessitated in order to protect the cornea from entrapped microorganisms.Studies have shown that autologous cell damage is avoided in closed eye tear fluid, by the accumulation of several modulators of complement activation, which shift activation towards opsonization of entrapped microorganisms and the build-up of a wide array of antiproteases . Some of the latter are likely to arise from the ocular surface tissues . Corneal neovascularization may be avoided in part by the build-up of alpha2-macroglobulin and the conversion of plasminogen to angiostatin . It is highly probable that other bioactive protein fragments are produced in the closed eye, which contribute to homeostasis . Areas of future study are indicated.

Anal Chem, 2000 Oct 1, 72(19), 4603 - 7
Capillary isoelectric focusing of yeast cells; Shen Y et al.; In the present work, capillary isoelectric focusing (CIEF) methods were developed for the separation and identification of yeast cells . Yeast cells (approximately 4-microm diameter) cultured to various phases of growth were shown to be reproducibly resolved by CIEF using 100-microm-i.d . fused-silica capillaries coated with hydroxypropyl methylcellulose . Separation efficiencies corresponding to peak capacities of >4000 were obtained . The suitable cell concentration range for obtaining repeatable elution in CIEF separations was found to be quite low (<3 cells/microL) . CIEF experiments showed that yeast cell populations at early log, mid log, and stationary growth phases differ in isoelectric point, with values ranging from 5.2 to 6.4 . The broader application of CIEF are projected for microorganism identification and separation based upon growth conditions.

Khirurgiia (Mosk), 2000, (9), 11 - 5
{Correction of the intraintestinal status in patients with diffuse peritonitis}; Kirkovskii VV et al.; Complex methods of intraintestinal status correction are proposed for patients surgically treated for general peritonitis . These methods consist of three main components: suppression of excessive bacterial colonization of gastrointestinal tract; binding of toxic substances and microorganisms; colonization of small intestine by physiological strains of bacteria . Original design of three-lumen tube for nasogastrointestinal intubation was used . Clinical study was carried out in 2 groups of patients . Study group consisted of 79 patients treated by proposed methods; only gastrointestinal intubation by three-lumen tube was performed in 44 patients (control group) . Usage of the proposed methods led to dysbacteriosis correction and fast appearance of intestinal peristalsis, improved the course of postoperative period . The mortality was 8.9% in the study group and 13.6% in the control group.

Burns, 2000 Dec, 26(8), 731 - 6
Bacteriology in burn patients undergoing mechanical ventilation; Garcia Bernal FJ et al.; In this paper the authors introduce a retrospective study of the incidence of infectious processes in the Burns Unit of the Cruces Hospital (Bilbao), in those patients treated between 1995 and 1998, and who needed, for different reasons, mechanical ventilatory support . The most common microorganisms found in wound cultures, plugged telescoping catheter and blood cultures and analyse variations throughout the stay in the Burns Unit are described.

Curr Opin Biotechnol, 2000 Oct, 11(5), 490 - 6
Novel approaches to the biosynthesis of vanillin; Walton NJ et al.; Microorganisms able to produce vanillin in excess of 6g/l from ferulic acid have now been isolated . In Pseudomonas strains, the metabolic pathway from eugenol via ferulic acid to vanillin has been characterised at the enzymic and molecular genetic levels . Attempts to introduce vanillin production into other organisms by genetic engineering have begun.

J Biol Chem, 2001 Jan 12, 276(2), 1424 - 33
Rh type B glycoprotein is a new member of the Rh superfamily and a putative ammonia transporter in mammals; Liu Z et al.; Ammonium transporters play a key functional role in nitrogen uptake and assimilation in microorganisms and plants; however, little is known about their structural counterpart in mammals . Here, we report the molecular cloning and biochemical characterization of Rh type B glycoproteins, human RhBG and mouse Rhbg, two new members of the Rh family with distinct tissue specificities . The RhBG orthologues possess a conserved 12-transmembrane topology and most resemble bacterial and archaeal ammonium transporters . Human RHBG resides at chromosome 1q21.3, which harbors candidate genes for medullary cystic kidney disease, whereas mouse Rhbg is syntenic on chromosome 3 . Northern blot and in situ hybridization revealed that RHBG and Rhbg are predominantly expressed in liver, kidney, and skin, the specialized organs involving ammonia genesis, excretion, or secretion . Confocal microscopy showed that RhBG is located in the plasma membrane and in some intracellular granules . Western blots of membrane proteins from stable HEK293 cells and from mouse kidney and liver confirmed this distribution . N-Glycanase digestion showed that RhBG/Rhbg has a carbohydrate moiety probably attached at the NHS motif on exoloop 1 . Phylogenetic clustering, tissue-specific expression, and plasma membrane location suggest that RhBG homologous proteins are the long sought major ammonium transporters in mammalians.

Clin Microbiol Rev, 2000 Oct, 13(4), 662 - 85
Fungal and parasitic infections of the eye; Klotz SA et al.; The unique structure of the human eye as well as exposure of the eye directly to the environment renders it vulnerable to a number of uncommon infectious diseases caused by fungi and parasites . Host defenses directed against these microorganisms, once anatomical barriers are breached, are often insufficient to prevent loss of vision . Therefore, the timely identification and treatment of the involved microorganisms are paramount . The anatomy of the eye and its surrounding structures is presented with an emphasis upon the association of the anatomy with specific infection of fungi and parasites . For example, filamentous fungal infections of the eye are usually due to penetrating trauma by objects contaminated by vegetable matter of the cornea or globe or, by extension, of infection from adjacent paranasal sinuses . Fungal endophthalmitis and chorioretinitis, on the other hand, are usually the result of antecedent fungemia seeding the ocular tissue . Candida spp . are the most common cause of endogenous endophthalmitis, although initial infection with the dimorphic fungi may lead to infection and scarring of the chorioretina . Contact lens wear is associated with keratitis caused by yeasts, filamentous fungi, and Acanthamoebae spp . Most parasitic infections of the eye, however, arise following bloodborne carriage of the microorganism to the eye or adjacent structures.

Microb Ecol, 2000 Aug, 40(2), 148 - 158
Relationships among Bacterial Cell Size, Productivity, and Genetic Diversity in Aquatic Environments using Cell Sorting and Flow Cytometry; Bernard L et al.; The study of relationships between cell size and productivity is of key importance in microbial ecology to understand which members of natural aquatic communities are responsible for the overall activity and/or productivity . Flow sorting of microorganisms from different environmental samples was used to analyze the activity of bacterial cells depending on their biovolume . Bacterial cells from five different natural samples taken along the Mediterranean coast including fresh- and seawaters were incubated with tritiated leucine, then stained with SYTO 13 and sorted by flow cytometry according to their average side-angle-scattered (SSC) light . In all samples, a bell-shaped relationship was found between cell biovolume and activity, whereas activity of a given cell-size class varied between samples . In contrast, an inverse relationship was found between biovolumes and abundances . These results suggest that medium-sized cells with highest growth rates are probably submitted to intense grazing . For one sample, bacteria within five different size classes were sorted and the genetic diversity of cells within each sorted size class and that of the whole community were analyzed by the denaturing gradient gel electrophoresis (DGGE) method . The genetic diversity, as determined at the community level was highly represented into the pool of small cells, whereas only few species were present into larger cell subpopulations . The results suggest that only a few genotypes may be dominant within the largest and most productive cells . Furthermore, cell size polymorphism as well as heterogeneous cellular activities were found within some species.

Microb Ecol, 2000 Aug, 40(2), 139 - 147
Improved Recoverability of Microbial Colonies from Marine Sponge Samples; Olson JB et al.; The growth of microorganisms from marine sponge samples was studied on various low to high nutrient solid media using media supplements . The supplements utilized were catalase, sodium pyruvate, and a combination of the two . Medium composition was found to influence the growth response on the supplemented media . Microorganisms on low nutrient media responded more favorably to the media additions than on high nutrient media . Thirty-five percent of the supplemented media demonstrated colony forming unit (CFU) recoveries that were 50% or greater than those of the unamended control plates . Twenty-one percent showed recoveries of more than 100% of the control values, with sodium pyruvate additions providing for the greatest overall increase in recovery, whether alone or in conjunction with catalase . These findings suggest that addition of catalase or sodium pyruvate to solid growth and isolation media may improve recoverability of microorganisms from natural samples.

J Infect Dis, 2000 Nov, 182(5), 1566 - 9 Epub 2000 Oct 09.
Identification of loci essential for the growth of Helicobacter pylori under acidic conditions; Bijlsma JJ et al.; To persist in the hostile acidic environment of the stomach, Helicobacter pylori must survive acid shock and grow at acidic pH . Of a library of 1250 random mutants screened for isolates unable to grow at low pH, 10 mutants were detected that were unable to grow at pH 4.8 . However, all 10 mutants were resistant to acid shock . Four mutants had an insertion in genes of unknown function . One mutant was affected in lepA, an orthologue of a membrane GTPase . Three mutants were disrupted in loci involved in the transport of H(+) ions or other cations (FRaseI, czcA, and aldo-keto reductase) . Two mutants were affected in loci that contribute to acid resistance in other microorganisms (uvrA and atpF') . Thus, at least 10 loci not related to urease are essential for the growth of H . pylori under acidic conditions and should be critical for lifelong infection by this pathogen.

Am J Perinatol, 2000, 17(2), 107 - 12
Neutrophil chemotaxis and random migration in preterm and term infants with sepsis; Turkmen M et al.; The aim of this study was to evaluate neutrophil chemotaxis and random migration in healthy newborn infants and septic neonates with similar gestational and postnatal age . Possible relationships between chemotactic activity, random migration, causative microorganisms, and clinical course of septic infants were also investigated . The neutrophil chemotaxis and random migration was evaluated in 24 healthy newborn babies and 34 septic neonates and 20 healthy adults by modified Boyden technique . The mean neutrophil chemotaxis of healthy preterm-term infants and adults were similar (66.6 +/- 18.9, 64.4 +/- 19.9, and 74.7 +/- 17 microm, respectively) . The mean neutrophil random migration of healthy term infants was not different than that of adults . But the mean neutrophil random migration of healthy preterm infants was lower than that of adults (36.9 +/- 13.7 and 43.5 +/- 1 1.8 microm, respectively) (p = 0.03) . The mean neutrophil chemotaxis and random migration septic term infants were not different from the value of healthy term infants (p > 0.05) . Although the mean random migration of septic and preterm infants were similar (p > 0.05), the mean neutrophil chemotaxis of septic preterm infants was lower than the value of healthy preterm infants (p = 0.04) . Not only mean neutrophil chemotaxis of septic preterm and term infants were significantly lower than that of adults (p = 0.002 and p = 0.006, respectively), but also neutrophil random migration of septic preterm and term infants were significantly lower than that of adults (p = 0.001 and p = 0.005, respectively) . There was no relationship between the nature of causative microorganism and neutrophil random migration or chemotactic activity . Polymorphonuclear leukocytes chemotaxis was significantly lower in preterm with sepsis compared with healthy preterm-term infants and adults . These findings may indicate deterioration in neutrophil functions in premature babies under stress but more detailed studies with larger groups are needed.

Xenotransplantation, 2000 Aug, 7(3), 221 - 9
Generation and testing of a highly specific anti-serum directed against porcine endogenous retrovirus nucleocapsid; Krach U et al.; Advances in xenotransplantation offer chances to alleviate the shortage of human donor organs . The discovery that pig endogenous retroviruses (PERV) can infect human cells in vitro has stimulated the discussion on infectious risk in xenotransplantation . A molecular and immunologic monitoring of xenograft recipients and of donor animals for putative infection with PERV and other microorganisms is inevitable . In this report, we describe the generation and testing of a highly specific anti-serum directed against the PERV nucleocapsid protein . The Gag amino acid (aa) sequence of PERV class B was used to define immunogenic domains by computer analysis . A peptide corresponding to the C-terminal 19 aa of the 10 kDa (p10) nucleocapsid (NC) portion of the Gag polyprotein was used to immunize rabbits . The generated serum was tested using recombinant PERV Gag protein expressed in insect cells, purified PERV virus particles and human 293 cells transfected or infected with PERV, respectively . Test methods included Western blotting, indirect immunofluorescence, immunoperoxidase assay and ELISA . The PERV anti-serum provides a tool that is instrumental for detection of a potential agent of zoonosis . It can be used for screening of donor animals and xenograft recipients in the course of xenotransplantation procedures.

Am J Med, 2000 Oct 1, 109(5), 398 - 421
Oxidants, nitrosants, and the lung; van der Vliet A et al.; The respiratory tract is subjected to a variety of environmental stresses, including oxidizing gases, particulates, and airborne microorganisms, that together, may injure structural and functional lung components and thereby jeopardize the primary lung function of gas exchange . To cope with such various environmental threats, the lung has developed elaborate defense mechanisms that include inflammatory-immune pathways as well as several antioxidant systems . These defense systems operate largely in extracellular spaces, thus protecting underlying bronchial and alveolar epithelial cells from injury, although these cells themselves are also active participants in such (inflammatory) defense mechanisms . Although potentially harmful, oxidants are increasingly recognized as pathophysiologic mediators produced primarily by inflammatory-immune cells as a host defense mechanism, but also by various other cell types as an intracellular mediator in various cell responses, thus affecting inflammatory-immune processes or inducing resistance . The molecular mechanisms and signaling pathways involved in such processes are the focus of much current investigation . Nitric oxide, a messenger molecule produced by many lung cell types, also modulates oxidant-mediated processes, thereby giving rise to a new family of reactive nitrogen species ("nitrosants") with potentially unique signaling properties . The complex role of oxidants and nitrosants in various pathophysiologic processes in the lung have confounded the design of therapeutic approaches with antioxidant substrates . This review discusses current knowledge regarding extracellular antioxidant defenses in the lung, and oxidant/nitrosant mechanisms operating under inflammatory-immune conditions and their potential contribution to common lung diseases . Finally, some recent developments in antioxidant therapeutic strategies are discussed.

Kansenshogaku Zasshi, 2000 Aug, 74(8), 630 - 7
{Clinical study of infection associated hemophagocytic syndrome}; Shiraishi K et al.; Hemophagocytic syndrome (HPS) causes pancytopenia, increased blood LDH level, liver dysfunction, DIC, etc . with macrophages appearing in the bone marrow, spleen, lymph nodes, etc . Adult HPS is mostly secondary to various infections, malignant tumors, etc . and sometimes has a serious outcome . Particularly infection associated HPS (IAHS) is triggered by viral, bacterial and fungal infections . The cases of unknown primary disease and suspected IAHS of unidentified pathogenic microorganism are often encountered in the clinical setting . The authors compared IAHS and malignant associated HPS (MAHS) and classified IAHS into viral associated HPS (VAHS), bacterial associated HPS (BAHS) and fungal types to compare the test values based on the test findings at the onset in the HPS cases treated at our Department . The patients consisted of 21 HPS cases, 11 IAHS cases (VAHS 4, BAHS 5, fungal 2) and 10 MAHS cases . Based on the test findings (WBC, Hb, Plt, LDH, ferritin, myelogram, cytokines, {IFN alpha, TNF gamma, IL-6, sIL-2R, M-CSF}, adhesion molecules {sICAM-1, sVCAM-1, sELAM-1, sL-selectin}) at the onset, a comparison between IAHS and MAHS and among the IAHS cases classified by pathogenic microorganism was made . In the comparison between IAHS and MAHS, the Hb value was significantly decreased and sIL-2R tended to be increased at the onset in MAHS . When comparing the IAHS cases by pathogenic microorganism, Plt was significantly decreased and sICAM-1 and sVCAM-1 were increased at the onset in the BAHS, The BAHS cases had serious underlying diseases and poor prognosis with high incidence of DIC complications . We are going to accumulate more cases for early diagnosis and treatment of IAHS.

Annu Rev Microbiol, 2000, 54, 289 - 340
ALGINATE LYASE: review of major sources and enzyme characteristics, structure-function analysis, biological roles, and applications; Wong TY et al.; Alginate lyases, characterized as either mannuronate (EC 4.2.2.3) or guluronate lyases (EC 4.2.2.11), catalyze the degradation of alginate, a complex copolymer of alpha-L-guluronate and its C5 epimer beta-D-mannuronate . Lyases have been isolated from a wide range of organisms, including algae, marine invertebrates, and marine and terrestrial microorganisms . This review catalogs the major characteristics of these lyases, the methods for analyzing these enzymes, as well as their biological roles . Analysis of primary sequence data identifies some markedly conserved motifs that should help elucidate functional domains . Information about the three-dimensional structure of a mannuronate lyase from Sphingomonas sp., combined with various mutagenesis studies, has identified residues that are important for catalytic activity in several lyases . Characterization of alginate lyases will enhance and expand the use of these enzymes to engineer novel alginate polymers for applications in various industrial, agricultural, and medical fields . In this review, we explore both past and present applications of this important enzyme and discuss its future prospects.

Nat Biotechnol, 2000 Oct, 18(10), 1071 - 4
Function-based isolation of novel enzymes from a large library; Olsen MJ et al.; Here we describe a high-throughput, quantitative method for the isolation of enzymes with novel substrate specificities from large libraries of protein variants . Protein variants are displayed on the surface of microorganisms and incubated with a synthetic substrate consisting of (1) a fluorescent dye (2) a positively charged moiety (3) the target scissile bond, and (4) a fluorescence resonance energy transfer (FRET) quenching partner . Enzymatic cleavage of the scissile bond results in release of the FRET quenching partner while the fluorescent product is retained on the cell surface, allowing isolation of catalytically active clones by fluorescence-activated cell sorting (FACS) . Using a synthetic substrate with these characteristics, we enriched Escherichia coli expressing the serine protease OmpT from cells expressing an inactive OmpT variant by over 5,000-fold in a single round . Screening a library of 6 x 10(5) random OmpT variants by FACS using a FRET peptide substrate with a nonpreferred Arg-Val cleavage sequence resulted in the isolation of variant proteases with catalytic activities enhanced by as much as 60-fold . This approach represents a potentially widely applicable method for high-throughput screening of large libraries on the basis of catalytic turnover.

Nat Biotechnol, 2000 Oct, 18(10), 1049 - 54
Status of genome projects for nonpathogenic bacteria and archaea; Nelson KE et al.; Since the first microbial genome was sequenced in 1995, 30 others have been completed and an additional 99 are known to be in progress . Although the early emphasis of microbial genomics was on human pathogens for obvious reasons, a significant number of sequencing projects have focused on nonpathogenic organisms, beginning with the release of the complete genome sequence of the archaeon Methanococcus jannaschii in 1996 . The past 18 months have seen the completion of the genomes of several unusual organisms, including Thermotoga maritima, whose genome reveals extensive potential lateral transfer with archaea; Deinococcus radiodurans, the most radiation-resistant microorganism known; and Aeropyrum pernix, the first Crenarchaeota to be completely sequenced . Although the functional characterization of genomic data is still in its initial stages, it is likely that microbial genomics will have a significant impact on environmental, food, and industrial biotechnology as well as on genomic medicine.

Cancer Res, 2000 Sep 15, 60(18), 5052 - 8
Cell-based screen for antimitotic agents and identification of analogues of rhizoxin, eleutherobin, and paclitaxel in natural extracts; Roberge M et al.; We describe a cell-based assay for antimitotic compounds that is suitable for drug discovery and for quantitative determination of antimitotic activity . In the assay, cells arrested in mitosis as a result of exposure to antimitotic agents in pure form or in crude natural extracts are detected by ELISA using the monoclonal antibody TG-3 . The assay was used to screen >24,000 extracts of marine microorganisms and invertebrates and terrestrial plants and to guide the purification of active compounds from 5 of 119 positive extracts . A new rhizoxin analogue was found in a Pseudomonas species, six new eleutherobin analogues were identified from the octocoral Erythropodium caribaeorum, and two paclitaxel analogues were found in the stem bark of the tree Ilex macrophylla . The assay was also used for quantitative comparison of the antimitotic activity of different analogues . It revealed the importance of the C-11 to C-13 segment of the diterpene core of eleutherobin for its antimitotic activity . The identification of antimitotic compounds in very low abundance and their high (0.5%) occurrence in natural extracts indicates that drug discovery efforts using this cell-based assay may lead to the identification of structurally novel antimitotic agents.

Biometals, 2000 Jun, 13(2), 165 - 8
Salicylic acid is not a bacterial siderophore: a theoretical study; Chipperfield JR et al.; Using a newly available program for calculating the concentrations and speciation of various ions (Pettit, LD & Powell KJ, 'SolEq' Academic Software, 1999), we have calculated that at pH 7 the amount of free Fe(III) present in an aqueous solution is 1.4 x 10(-9) M and not 10(-18) M as is usually quoted . In the presence of salicylic acid, included in the calculations at 10(-4) M, the solubility of Fe(III) is increased to only 9.8 x 10(-9) M suggesting that salicylate is unable to act as a siderophore although it is produced as an extracellular product by several bacterial genera when grown iron deficiently . In the presence of 40 mM phosphate, the soluble Fe(III) concentration is decreased by 10(4) at pH 7 and again this is hardly affected by the presence of salicylate . Thus, for microorganisms grown either in vitro or in vivo, salicylate is unlikely to function as a iron solubilizing agent . The same conclusions may also apply to 2,3-dihydroxybenzoic acid.

Acta Cytol, 2000 Sep-Oct, 44(5), 835 - 9
Cytologic diagnosis of leishmaniasis in HIV infection . A report of eight cases; Vicandi B et al.; BACKGROUND: Leishmania organisms are among the intracellular microorganisms with a tendency to develop in patients with the acquired immunodeficiency syndrome (AIDS) . With increasing travel to endemic areas by patients with human immunodeficiency virus (HIV) infection, it is becoming a more-frequent diagnosis in nonendemic areas . CASES: Ten cytologic specimens from eight patients with leishmaniasis and AIDS were reviewed . Eight samples were obtained from lymph nodes through fine needle aspiration (FNA) . Another sample was obtained after scraping a tongue ulcer . The last one was an ascitic fluid specimen . Smears showed numerous parasitized histiocytes with abundant intracellular Leishmania organisms (amastigotes) . Extracellular microorganisms were also abundant . Diff-Quik-stained smears allowed the clear recognition of the characteristic morphologic appearance with a deep-staining area (nuclei) and paranuclear zone (kinetoplast) . Intracellular organisms were round, while single, extracellular forms were a more elongated . CONCLUSION: The polymorphous clinical manifestations usually seen in patients suffering from leishmaniasis and AIDS constitute a diagnostic challenge that can be facilitated by cytopathologic examination . Cytology permits easy and rapid identification of Leishmania amastigotes, allowing a specific diagnosis and treatment.

J Clin Microbiol, 2000 Oct, 38(10), 3864 - 6
Clinical comparison of nonvented aerobic BacT/Alert blood culture bottle and standard aerobic bottle for detection of microorganisms in blood; Snyder JW et al.; The current BacT/Alert standard aerobic (VA) blood culture bottle was redesigned and designated a nonvented aerobic (NVA) culture bottle; this bottle does not require venting . A total of 3,873 sets of blood samples for culture were obtained from adult patients with suspected bacteremia or fungemia . The NVA bottle showed performance equivalent to that of the VA bottle for recovery and speed of detection of microorganisms from blood without the need for venting the bottle.

Genetics, 2000 Oct, 156(2), 699 - 709
Male-killing Wolbachia in Drosophila: a temperature-sensitive trait with a threshold bacterial density; Hurst GD et al.; Inherited microorganisms that disturb the reproduction of their host have been characterized from a number of host taxa . To understand the general principles underlying the genetic and mechanistic basis of interactions, study of different agents in model host species is required . To this end, the nature and genetics of the maternally inherited sex-ratio trait of Drosophila bifasciata were investigated . Successful curing of affected lines with antibiotics demonstrated this trait was associated with the presence of a bacterium, and molecular systematic analysis demonstrated an association between the presence of the trait and infection with an A group Wolbachia . The penetrance and heritability of the trait did not vary with maternal age . Exposure to elevated temperatures did reduce trait penetrance but did not affect heritability . Examination of the effect of temperature on bacterial density in eggs revealed a decrease in bacterial density following exposure of the parent to elevated temperature, consistent with the hypothesis that male killing in D . bifasciata requires a threshold density of Wolbachia within eggs . The male offspring produced following exposure to elevated temperatures were infected with Wolbachia on emergence as adults . Crossing studies demonstrated a weak cytoplasmic incompatibility phenotype exhibited by Wolbachia in these males . The results are discussed with respect to the incidence of male killing within the clade Wolbachia, the general nature of Wolbachia-host interactions, and the prospects for using this association to investigate the mechanism of male killing.

Eur J Clin Microbiol Infect Dis, 2000 Aug, 19(8), 638 - 40
Prosthetic valve endocarditis caused by Mycoplasma hominis; Blasco M et al.; Mycoplasma hominis endocarditis is extremely uncommon and difficult to diagnose . Atypical growth characteristics in routine bacterial culture and an inability to demonstrate the organism using Gram staining can lead to a delayed diagnosis of Mycoplasma hominis infections, and the organism is often missed . This report describes a patient with Mycoplasma hominis prosthetic valve endocarditis . The microorganism was recovered from the mitral prosthesis but was missed in blood cultures . This finding suggests that Mycoplasma hominis should be considered in the differential diagnosis of culture-negative endocarditis.

Appl Environ Microbiol, 2000 Oct, 66(10), 4475 - 80
PCR assays that identify the grapevine dieback fungus Eutypa lata; Lecomte P et al.; Eutypa lata is the causal fungal agent of Eutypa dieback, a serious grapevine necrotic disease . The erratic and delayed (1 to 2 months) appearance of characteristic conidia on culture media and the presence of numerous microorganisms in decaying wood make it difficult either to identify or to detect E . lata in grapevine wood samples . We designed six pairs of PCR primers for diagnosis of E . lata . Three primer pairs were derived from ribosomal DNA internal transcribed spacer sequences, and three pairs were derived from randomly amplified polymorphic DNA fragments . The six primer pairs could be used to amplify DNAs extracted from all of the E . lata isolates tested . They did not amplify DNAs from fungi and bacteria representing more than 50 different species of microorganisms associated with grapevine . We developed a simple protocol, leading to a rapid release of DNA, that enabled us to identify E . lata from pure or mixed cultures as well as from grapevine wood samples . Identification of E . lata in wood was achieved within a few hours, instead of the several weeks required for classical cultures on agar medium . We believe that the procedure described here can be adapted to detect other microorganisms involved in woody plant diseases.

Appl Environ Microbiol, 2000 Oct, 66(10), 4258 - 65
A bead-based method for multiplexed identification and quantitation of DNA sequences using flow cytometry; Spiro A et al.; A new multiplexed, bead-based method which utilizes nucleic acid hybridizations on the surface of microscopic polystyrene spheres to identify specific sequences in heterogeneous mixtures of DNA sequences is described . The method consists of three elements: beads (5.6-microm diameter) with oligomer capture probes attached to the surface, three fluorophores for multiplexed detection, and flow cytometry instrumentation . Two fluorophores are impregnated within each bead in varying amounts to create different bead types, each associated with a unique probe . The third fluorophore is a reporter . Following capture of fluorescent cDNA sequences from environmental samples, the beads are analyzed by flow cytometric techniques which yield a signal intensity for each capture probe proportional to the amount of target sequences in the analyte . In this study, a direct hybrid capture assay was developed and evaluated with regard to sequence discrimination and quantitation of abundances . The target sequences (628 to 728 bp in length) were obtained from the 16S/23S intergenic spacer region of microorganisms collected from polluted groundwater at the nuclear waste site in Hanford, Wash . A fluorescence standard consisting of beads with a known number of fluorescent DNA molecules on the surface was developed, and the resolution, sensitivity, and lower detection limit for measuring abundances were determined . The results were compared with those of a DNA microarray using the same sequences . The bead method exhibited far superior sequence discrimination and possesses features which facilitate accurate quantitation.

Appl Environ Microbiol, 2000 Oct, 66(10), 4222 - 9
Evolution of thermotolerance in hot spring cyanobacteria of the genus Synechococcus; Miller SR et al.; The extension of ecological tolerance limits may be an important mechanism by which microorganisms adapt to novel environments, but it may come at the evolutionary cost of reduced performance under ancestral conditions . We combined a comparative physiological approach with phylogenetic analyses to study the evolution of thermotolerance in hot spring cyanobacteria of the genus Synechococcus . Among the 20 laboratory clones of Synechococcus isolated from collections made along an Oregon hot spring thermal gradient, four different 16S rRNA gene sequences were identified . Phylogenies constructed by using the sequence data indicated that the clones were polyphyletic but that three of the four sequence groups formed a clade . Differences in thermotolerance were observed for clones with different 16S rRNA gene sequences, and comparison of these physiological differences within a phylogenetic framework provided evidence that more thermotolerant lineages of Synechococcus evolved from less thermotolerant ancestors . The extension of the thermal limit in these bacteria was correlated with a reduction in the breadth of the temperature range for growth, which provides evidence that enhanced thermotolerance has come at the evolutionary cost of increased thermal specialization . This study illustrates the utility of using phylogenetic comparative methods to investigate how evolutionary processes have shaped historical patterns of ecological diversification in microorganisms.

Rev Argent Microbiol, 2000 Jul-Sep, 32(3), 157 - 60
{Relationship between rhodamine 6G accumulation and fluconazole resistance in Saccharomyces cerevisiae S288c}; Stella CA et al.; Severe mycotic infections are a source of concern in immunocompromised patients or in those who receive chemotherapy for hematological malignant diseases . One of the causes is referred to the appearance of antimycotic resistant microorganisms . Fluconazole is one of the antimycotic used for invasive mycoses treatment . Therefore it is necessary to evaluate the factors that originate this resistance . In the present report the yeast Saccharomyces cerevisiae S288c was used as a model system . In resistant strains the accumulation of the lipophilic cation Rhodamine 6G, L-leucine uptake and growth inhibition by crystal violet dye were determined . The results presented herein demonstrate the correlation between the membrane potential and the resistance to fluconazole presented by S . cerevisiae strain S288c.

Mikrobiologiia, 2000 Jul-Aug, 69(4), 581 - 5
{Microsampling of rhizosphere soil and laboratory artefacts}; Polianskaia LM et al.; A parallel analysis of the microsamples of surrounding soil and microsamples of rhizosphere soil did not reveal the so-called rhizospheric effect . The data obtained showed that dilution significantly influences the results of determination of the number of soil microorganisms . The actual number of microorganisms revealed in soil samples greatly differed from the theoretically predicted values . The enumeration of microorganisms in soil microsamples by direct count and, especially, by the plating method with the use of conversion coefficients based on the degree of sample dilution gave erroneous results.

Mikrobiologiia, 2000 Jul-Aug, 69(4), 541 - 52
{Effect of microorganisms and seasonal factors on the isotope composition of organic carbon from Black Sea suspensions}; Ivanov MV et al.; The isotopic composition of particulate organic carbon (POC) from the Black Sea deep-water zone was studied during a Russian-Swiss expedition in May 1998 . POC from the upper part of the hydrogen sulfide zone (the C-layer) was found to be considerably enriched with the 12C isotope, as compared to the POC of the oxycline and anaerobic zone . In the C-layer waters, the concurrent presence of dissolved oxygen and hydrogen sulfide and an increased rate of dark CO2 fixation were recorded, suggesting that the change in the POC isotopic composition occurs at the expense of newly formed isotopically light organic matter of the biomass of autotrophic bacteria involved in the sulfur cycle . In the anaerobic waters below the C-layer, the organic matter of the biomass of autotrophs is consumed by the community of heterotrophic microorganisms; this results in weighting of the POC isotopic composition . Analysis of the data obtained and data available in the literature allows an inference to be made about the considerable seasonable variability of the POC delta 13C value, which depends on the ratio of terrigenic and planktonogenic components in the particulate organic matter.

Schweiz Arch Tierheilkd, 2000 Jul, 142(7), 367 - 73
{Ehrlichiosis in Switzerland--significance for veterinary medicine}; Pusterla N et al.; Ehrlichiosis is a rickettsial disease of animals and humans caused by various species of Ehrlichia . These obligate intracellular microorganisms infect granulocytes or monocytes of mammalian hosts and are transmitted mostly by ticks . The febrile disease is often undiagnosed and characterized by leukopenia, anemia and thrombocytopenia . The diagnosis of ehrlichiosis is based on clinical findings, tick infestation, direct or indirect detection of the agent, and serology . The role of native and imported ehrlichiae of animals in Switzerland is discussed.

Childs Nerv Syst, 2000 Aug, 16(8), 503 - 6; discussion 507
Craniocerebral injury resulting from transorbital stick penetration in children; Di Roio C et al.; OBJECTS: Two children were admitted to hospital for treatment of craniocerebral injury with transorbital penetration . METHODS: One child aged 6 years and 6 months had poked a chopstick in his orbit . There was no report of either a palpebral or an ocular wound . He had subsequently developed a meningeal syndrome with a cerebral abscess managed by needle aspiration biopsy and intravenous antibiotics . The other child, aged 4, had fallen onto a metal rod . He presented with a palpebral wound, motor disorders and coma, all due to a frontal intracerebral hematoma . There was an improvement in outcome without complications of an infectious nature or motor sequelae . CONCLUSIONS: Such head injuries are rare . Clinical, radiological and ophthalmological investigations must be performed, including computed tomography (CT) scan or cerebral magnetic resonance imaging (MRI) with antibiotic treatment for suspected microorganisms.

Sci Total Environ, 2000 Aug 21, 258(1-2), 119 - 27
Microbial interactions with tributyltin compounds: detoxification, accumulation, and environmental fate; Gadd GM; While inorganic forms of tin are of relatively low toxicity towards microorganisms, the more lipid-soluble organotins can be highly toxic . Generally, trisubstituted (R3SnX) organotins are more toxic than di- (R2SnX2) and monosubstituted (RSnX3) compounds; the anion (X) apparently having little influence on toxicity . However, many microorganisms exhibit resistance to organotins, a phenomenon of relevance to the environmental cycling of organotins and also to novel biological methods of treatment . Organotin degradation can involve the sequential removal of organic moieties to yield less toxic derivatives, e.g . debutylation of tributyltin compounds to di- and monobutylins . Such degradation is known to take place in bacteria, algae and fungi, and this provides one route for detoxification . In addition, microorganisms are capable of accumulating tributyltin compounds, and this is another mechanism of removal from solution . The high lipid solubility of organotins ensures cell penetration and association with intracellular sites, while cell wall components also play an important role . Of the fungal wall components, melanin pigments are capable of TBT binding, and the addition of melanin to growing cultures can remove toxicity; melanised strains are also more sensitive than albino strains of the same species . To date, little attention has been paid to the biotechnological exploitation of these interactions for the degradation of tributyltin or its removal from solution . This paper describes some interactions of microorganisms (bacteria, cyanobacteria, microalgae, and fungi) with tributyltin compounds, with particular reference to toxicity, bioaccumulation and detoxification . Such processes should receive due consideration in any environmental management programme.

Sci Total Environ, 2000 Aug 21, 258(1-2), 103 - 10
Sea-nine antifoulant: an environmentally acceptable alternative to organotin antifoulants; Jacobson AH et al.; This article reviews previously reported data on the performance, environmental fate, and environmental modeling of Sea-Nine 211 antifoulant (4,5-dichloro-2-n-octyl-4-isothiazolin-3-one) . Since organotins are an industry standard, the environmental fate and environmental modeling results of tributyltin (TBT) are compared to those of the Sea-Nine antifoulant for reference . Laboratory and field tests results have shown Sea-Nine antifoulant to be highly effective . Five years of commercial use has confirmed this . Sea-Nine antifoulant and TBT were compared in an environmental risk assessment to predict their effects on the environment . Sea-Nine antifoulant was degraded rapidly in the environment by microorganisms . Its half-life in aerobic and anaerobic microcosm studies was less than 1 h . TBT degraded slowly under aerobic and anaerobic conditions with half-lives ranging from 6 to 9 months . The degradation products of Sea-Nine antifoulant were ring-opened compounds with greatly reduced toxicity . TBT degraded to dibutyltin species, which were still toxic and persistent in the environment . Bioaccumulation studies in fish showed essentially no bioaccumulation of the Sea-Nine biocide . The bioaccumulation of TBT was significant, with bioconcentration factors as high as 10000 . The Sea-Nine antifoulant showed no chronic or reproductive toxicity to marine species, while TBT showed a wide range of effects on growth, development, and reproduction at levels as low as 2 parts per trillion (ppt) . Computer modeling using the Exposure Analysis Modeling System (EXAMS) predicted maximum concentrations of Sea-Nine biocide of up to 10 ppt, far below the maximum acceptable environmental concentration (MAEC) of 630 ppt . The maximum predicted concentrations of TBT were as high as 345 ppt, far above the UK Environmental Standard in seawater of 2 ppt.

J Periodontal Res, 2000 Oct, 35(5), 285 - 90
Glucocorticoid receptor antagonist RU 486 treatment reduces periodontitis in Fischer 344 rats; Breivik T et al.; Inappropriate hypothalamic pituitary adrenal (HPA) axis regulation of immune responses to bacterial challenges has been found to play an important role in infections and inflammatory disease susceptibility and progression . In the present study we investigated the tissue effects of experimental periodontitis in Fischer 344 rats, which were subcutaneously (s.c.) injected with 20 mg/kg of the glucocorticoid receptor antagonist and active antiglucocorticoid agent RU 486 every second day over a period of 14 d . Periodontitis was induced by placing a bacterial plaque retentive silk ligature in the gingival sulcus around the neck of maxillary right 2nd molar teeth 1 d after the first injection in 10 RU 486-treated and 10 vehicle (1,2-propanediol)-treated control animals . The contralateral maxillary left 2nd molars served as internal control teeth for naturally occurring periodontitis . Disease progression was evaluated radiographically and histometrically . The average level of corticosterone in blood at sacrifice was significantly lower in the RU 486-treated animals as compared to controls . The experimental animals also developed significantly less periodontal breakdown at both experimental and control teeth compared to the vehicle-treated control animals . The results support our recent findings showing that HPA hyper-reactivity, either genetically determined or experimentally induced, stimulates periodontal disease susceptibility . These findings suggest that central nervous regulation of inflammatory responses to dental plaque microorganisms in the gums may modulate periodontal disease susceptibility and progression.

Biochim Biophys Acta, 2000 Aug 31, 1481(1), 119 - 30
Characterization of a heme c nitrite reductase from a non-ammonifying microorganism, Desulfovibrio vulgaris Hildenborough; Pereira IA et al.; A cytochrome c nitrite reductase (NiR) was purified for the first time from a microorganism not capable of growing on nitrate, the sulfate-reducing bacterium Desulfovibrio vulgaris Hildenborough . It was isolated from the membranes as a large heterooligomeric complex of 760 kDa, containing two cytochrome c subunits of 56 and 18 kDa . This complex has nitrite and sulfite reductase activities of 685 micromol NH(4)(+)/min/mg and 1.0 micromol H(2)/min/mg . The enzyme was studied by UV-visible and electron paramagnetic resonance (EPR) spectroscopies . The overall redox behavior was determined through a visible redox titration . The data were analyzed with a set of four redox transitions, with an E(0)' of +160 mV (12% of total absorption), -5 mV (38% of total absorption), -110 mV (38% of total absorption) and -210 mV (12% of total absorption) at pH 7.6 . The EPR spectra of oxidized and partially reduced NiR show a complex pattern, indicative of multiple heme-heme magnetic interactions . It was found that D . vulgaris Hildenborough is not capable of using nitrite as a terminal electron acceptor . These results indicate that in this organism the NiR is not involved in the dissimilative reduction of nitrite, as is the case with the other similar enzymes isolated so far . The possible role of this enzyme in the detoxification of nitrite and/or in the reduction of sulfite is discussed.

An Esp Pediatr, 2000 Mar, 52(3), 238 - 41
{Ureaplasma urealyticum and pertussis-like syndrome}; Ferrer Marcelles A et al.; BACKGROUND: Ureaplasma urealyticum is associated with respiratory pathology in the neonates and preterm neonates . However, this association has been poorly studied in infants and during early infancy . To address this issue, a clinic evaluation of patients with whooping cough and isolation of U . urealyticum in their nasopharyngeal aspirates has been done . METHODS: Over a period of 11 years, 1063 nasopharyngeal aspirates from 905 infants were studied . Clinical samples were cultured for Bordetella spp., other bacteria, viruses and mycoplasma . Data of patients with positive cultures for U . urealyticum were obtained from clinical records . RESULT: U . urealyticum was isolated from 26 patients with a median age of 5 months (range: 23 days-22 months) . The gestational age of 9 patients (34.6%) was less than 37 weeks . All the patients were hospitalised because of pertussis-like syndrome, which was associated with respiratory distress due to bronchospasm in 18 patients (69.2%) . Twelve patients (46.1%) had fever and 15 (57.7%) showed lymphocytosis . The chest roentgenogram was abnormal in 18 patients (69.2%): pulmonary hyperaeration, with or without atelectasis . Clinical evolution was good in all patients . In 16 patients (61.5%) U . urealyticum was isolated together with other microorganisms: in 9 samples with bacteria (H . influenzae, S . pneumoniae, B . pertussis, M . catarrhalis), in 5 with viruses (respiratory syncytial virus, cytomegalovirus, adenovirus, enterovirus) and in 2 samples with respiratory syncytial virus and S . pneumoniae and B . pertussis respectively . CONCLUSIONS: Likely U . urealyticum cannot be considered clearly as the etiologic agent of whooping cough, mainly because in the 61.5% of patients U . urealyticum has been isolated together with other microorganisms considered pathogens or potentially pathogens . Future studies would be necessary in order to establish the pathogenic role of U . urealyticum after the neonatal period.

Eur Radiol, 2000, 10(7), 1169 - 83
Pulmonary complications of liver transplantation: radiological appearance and statistical evaluation of risk factors in 300 cases; Golfieri R et al.; The aim of this study was to evaluate the incidence, radiographic appearance, time of onset, outcome and risk factors of non-infectious and infectious pulmonary complications following liver transplantation . Chest X-ray features of 300 consecutive patients who had undergone 333 liver transplants over an 11-year period were analysed: the type of pulmonary complication, the infecting pathogens and the mean time of their occurrence are described . The main risk factors for lung infections were quantified through univariate and multivariate statistical analysis . Non-infectious pulmonary abnormalities (atelectasis and/or pleural effusion: 86.7%) and pulmonary oedema (44.7%) appeared during the first postoperative week . Infectious pneumonia was observed in 13.7%, with a mortality of 36.6% . Bacterial and viral pneumonia made up the bulk of infections (63.4 and 29.3%, respectively) followed by fungal infiltrates (24.4 %) . A fairly good correlation between radiological chest X-ray pattern, time of onset and the cultured microorganisms has been observed in all cases . In multivariate analysis, persistent non-infectious abnormalities and pulmonary oedema were identified as the major independent predictors of posttransplant pneumonia, followed by prolonged assisted mechanical ventilation and traditional caval anastomosis . A "pneumonia-risk score" was calculated: low-risk score ( < 2.25) predicts 2.7% of probability of the onset of infections compared with 28.7% of high-risk (> 3.30) population . The "pneumonia-risk score" identifies a specific group of patients in whom closer radiographic monitoring is recommended . In addition, a highly significant correlation (p < 0.001) was observed between pneumonia-risk score and the expected survival, thus confirming pulmonary infections as a major cause of death in OLT recipients.

Immunogenetics, 2000 Sep, 51(11), 955 - 64
The homologue of mannose-binding lectin in the carp family Cyprinidae is expressed at high level in spleen, and the deduced primary structure predicts affinity for galactose; Vitved L et al.; Mannose-binding lectin (MBL) participates in the innate immune system as an activator of the complement system and as an opsonin after binding to certain carbohydrate structures on microorganisms . We isolated and characterized cDNA transcripts encoding an MBL homologue from three members of the carp family Cyprinidae, the zebrafish Danio rerio, the goldfish Carassius auratus, and the carp Cyprinus carpio . The carp and zebrafish transcripts contain two polyadenylation sites and RT-PCR on mRNA from carp tissues revealed the carp transcript to be most prominently expressed in the spleen . The deduced mature proteins contain 228 or 233 amino acids with a short N-terminal segment containing a single conserved cysteine expected to form interchain disulfide bridges, a collagen domain interrupted by four amino acids between two glycine residues, a neck region predicted to form an alpha-helical coiled-coil structure, and a C-terminal carbohydrate recognition domain (CRD) . Several of the structurally important residues in the CRD are conserved, but the residues known to interact with the calcium ion and hydroxyl groups of the carbohydrate ligand are different . The amino acid motif EPN, important for mannose specificity, was QPD in the Cyprinidae homologue, suggesting specificity for galactose instead . The identity between the deduced amino acid sequences is more than 90% between the carp and the goldfish and 68% and 65% between these two species, respectively, and the zebrafish . The identity with bird and mammalian MBLs ranges from 28 to 33%.

Med Clin (Barc), 2000 Jul 8, 115(6), 201 - 4
{Effects of Helicobacter pylori eradication on the recurrence of gastric ulcer during a 12-month follow up}; Bermejo F et al.; BACKGROUND: To study the influence of Helicobacter pylori eradication on the incidence of ulcer recurrence during 12 months of follow-up in gastric ulcer patients . PATIENTS AND METHOD: Seventy-three patients with gastric ulcer were prospectively studied . At endoscopy two biopsies from both antrum and body for haematoxylin-eosin staining and one for rapid urease test were obtained . Likewise, serology and 13C-urea breath test were carried out . Fifty-six H . pylori infected patients were monitored after giving an eradication therapy with omeprazole, clarithromycin and amoxicillin . A first control endoscopy was performed immediately after completing treatment to confirm ulcer healing . A second control endoscopy (with histologic study) and a breath test were performed one month after completing therapy (eradication was defined as the absence of H . pylori by both methods) . Finally, an endoscopy was repeated at 6 and 12 months to study ulcer recurrences . RESULTS: Mean age was 54 +/- 13 years (69% males) . Cumulative ulcer recurrence rate for 12 months, respectively for patients with eradication success and failure, was 2.3% (95% CI, 0-12%) and 70% (34-93%) (chi 2: 23.9; p < 0.0001) . Comparison between Kaplan-Meier curves for ulcer recurrence depending on H . pylori eradication showed significant differences (log-rank test; chi 2: 33.8; p < 0.0001) . A patient successfully treated underwent ulcer recurrence while receiving treatment with acetylsalicylic acid, without recurrence of the infection . CONCLUSIONS: H . pylori eradication is associated with a dramatic reduction on the recurrence of gastric ulcer, with a cumulative recurrence rate during 12 months of only 2.3%, which suggests that definitive cure of gastric ulcer disease is possible by means of microorganism eradication.

Microsc Microanal, 2000 Sep, 6(5), 463 - 470
Electron Spectroscopic Imaging of Magnetotactic Bacteria: Magnetosome Morphology and Diversity; Lins U et al.; Magnetotactic bacteria from aquatic environments were analyzed with the electron spectroscopic imaging technique . Rod-shaped bacteria and cocci were present in most of the samples observed . Magnetotactic multicellular aggregates were also observed at some of the sampling sites . The use of electron spectroscopic imaging allowed the observation of magnetosomes inside magnetotactic microorganisms with exceptional clarity . The number, size, and morphology of magnetosomes, as well as their ultrastructural spatial disposition inside the bacterial cell, could be directly observed and associated with the disposition of flagella of the respective cells.This allowed us to examine the structural relationships between magnetosomes and flagella, which are important components in the mechanisms of magnetotaxis . In disrupted magnetotactic multicellular aggregates, connections between cells were also visualized . We believe this technique will be useful in studying not only magnetotactic bacteria but also other uncultured microorganisms from natural environments.

J Microbiol Methods, 2000 Sep, 42(1), 81 - 6
Gel microdroplet technique leaving microorganisms alive for sorting by flow cytometry; Katsuragi T et al.; Fluorescent labels used to disclose cellular function and the like are generally needed for cytometric analysis, but suitable ones are not always available . Thiamin, an example of such a label, was used as a model in this study . Thiamin in cells of bakers' yeast can be chemically converted to thiochrome, which fluoresces strongly, but the reaction kills cells not protected inside a gel microdroplet (GMD) . Our new procedure for preparation of a small amount of GMDs uses a glass filter with micropores uniform in size to make an emulsion of molten agar in mineral oil that is then chilled for gelation of the agarose . Cells were suspended and mixed with the warm agarose, which was used to make GMDs . Cells were grown into microcolonies in the GMDs, which were then treated to convert thiamin to thiochrome . The thiochrome in microcolonies in single GMDs could be detected by flow cytometry . Plating showed that enough cells survived for this method to be used for screening . This technique can be used for all applications of GMDs.

J Microbiol Methods, 2000 Sep, 42(1), 75 - 9
Nucleic acid-based fluorescent probes in microbial ecology: application of flow cytometry; Porter J et al.; Microorganisms in natural environments have often been treated as 'black box' systems . Researchers have measured the inputs and outputs of the box, and have made bulk measurements on cell behaviour . However, unravelling the details of the diversity and interactions that exist within these microbial populations has proven exceptionally difficult . The information gained from the black box approach has been invaluable, and has allowed models of global foodwebs to be generated and tested . However, there is still little information about the interactions of individual microbial cells within natural populations . Such studies are essential to fully understand the integrated functioning of ecosystems . To achieve this goal, researchers need to be able to identify individual cells within a population, enumerate them, estimate both viability and activity, and monitor changes in response to relevant parameters . Due to the diversity, heterogeneity and numbers of cells that make up these populations, these measurements require automation and speed . At present, the use of flow cytometry in conjunction with nucleic acid probes provides an excellent method with which to pursue such studies.

Curr Biol, 2000 Sep 21, 10(18), 1139 - 42
Recognition of CpG DNA is mediated by signaling pathways dependent on the adaptor protein MyD88; Schnare M et al.; The innate immune system evolved to recognize conserved microbial products, termed pathogen-associated molecular patterns (PAMPs), which are invariant among diverse groups of microorganisms . PAMPs are recognized by a set of germ-line encoded pattern recognition receptors (PRRs) . Among the best characterized PAMPs are bacterial lipopolysaccharide (LPS), peptidoglycan (PGN), mannans, and other constituents of bacterial and fungal cell walls, as well as bacterial DNA . Recognition of bacterial DNA is the most enigmatic of these, as it depends on a particular sequence motif, called the CpG motif, in which an unmethylated CpG present in a particular sequence context accounts for a potent immunostimulatory activity of CpG DNA . Receptor(s) of the innate immune system that mediate recognition of CpG DNA are currently unknown . Here, we report that recognition of CpG DNA requires MyD88, an adaptor protein involved in signal transduction by the Toll-like receptors (TLRs), essential components of innate immune recognition in both Drosophila and mammals {1,2} . Signaling induced by CpG DNA was found to be unaffected in cells deficient in TLR2 or TLR4, suggesting that some other member of the Toll family mediates recognition of bacterial DNA.

FEBS Lett, 2000 Sep 15, 481(2), 189 - 92
Human acylation stimulating protein enhances triacylglycerol biosynthesis in plant microsomes; Weselake RJ et al.; Diacylglycerol acyltransferase has a universal role in catalyzing the acyl-CoA-dependent formation of triacylglycerol in microorganisms, animals and plants . Acylation stimulating protein, from human blood, is known to enhance diacylglycerol acyltransferase activity and triacylglycerol biosynthesis in human adipocytes . In the current study, acylation stimulating protein was also shown to enhance diacylglycerol acyltransferase activity in microsomes from cell suspension cultures of oilseed rape . Enzyme stimulation occurred over the pH range of 6-9 but the degree of stimulation decreased with increasing ionic strength at pH 7.4 . Varying acyl-CoA concentration did not affect the degree of stimulation . Membranes from triacylglycerol producing cells in plants and humans may have similar binding sites for acylation stimulating protein which have been preserved during molecular evolution . The results suggest that human acylation stimulating protein may be useful in modifying lipid biosynthesis in plants.

Berl Munch Tierarztl Wochenschr, 2000 Jul-Aug, 113(7-8), 279 - 83
{Investigations on airborne microorganisms in animal stables . 3: Relationship between inhalable endotoxin, inhalable dust and airborne bacteria in a hen house}; Zucker BA et al.; The relationship between inhalable endotoxin, inhalable dust and airborne bacteria was studied in a hen house . Neither the concentration of inhalable dust nor the concentration of airborne bacteria are suitable to reflect the concentration of airborne endotoxin . Furthermore it was found that the endotoxic activity can persist over a long period of time in dust samples . Therefore an accumulation of endotoxin in different environments is possible . Airborne endotoxin seems to be a suitable marker to characterize exposure to airborne organic dust, since this toxin is responsible for different respiratory diseases (e.g . toxic pneumonitis, airway obstructions) and the toxic activity of endotoxin in dust samples is known to persist for a long time.

Biosci Biotechnol Biochem, 2000 Aug, 64(8), 1737 - 42
Phylogenetic analysis of methanogens in sheep rumen ecosystem and detection of Methanomicrobium mobile By fluorescence in situ hybridization; Yanagita K et al.; The population of methanogens in the sheep rumen microbial ecosystem was studied by using 16S rDNA cloning analysis, epifluorescence microscopy (which detects autofluorescence of a specific cofactor F420 in methanogens) and the 16S rRNA-targeted in situ hybridization technique . The 16S rDNA clone libraries were constructed by PCR amplification with an Archaea-specific primer set and partial sequencing of the clonal 16S rDNAs was done . Phylogenetic analysis indicated that the clones were affiliated with Methanomicrobium ruminantium and mobile, Methanobrevibacter smithii . Epifluorescence microscopy (F420 autofluorescence) and in situ hybridization by using a newly designed M . mobile-specific 16S rRNA-targeted oligonucleotide probe found that methanogens accounted for approximately 3.6% of total ruminal microorganisms and approximately 54% of the total methanogens were M . mobile.

J Urol, 2000 Oct, 164(4), 1221 - 8
Bacterial dna sequences in prostate tissue from patients with prostate cancer and chronic prostatitis; Krieger JN et al.; PURPOSE: Although bacterial genetic material has been detected in prostate tissue from patients with various disorders, the prevalence of these organisms is unknown . We tested the hypothesis that bacterial detection rates differ between patients with prostate cancer and those with the chronic prostatitis/pelvic pain syndrome . MATERIALS AND METHODS: Sterile prostate biopsies were obtained during radical retropubic prostatectomy from 107 patients with prostate cancer and using a perineal approach from 170 with the chronic prostatitis/pelvic pain syndrome . Numerous controls were also evaluated . Bacterial ribosomal encoding DNA (165 rDNA) sequences were detected using a polymerase chain reaction assay . Selected positives were cloned, sequenced and compared with DNA databases . RESULTS: Bacterial DNA sequences were detected in 21 (19 . 6%) of 107 patients with prostate cancer compared to 79 (46.4%) of 170 with chronic prostatitis (p <0.0001) . These bacteria included urogenital pathogens, other described microorganisms and bacteria not reported previously . CONCLUSIONS: Bacterial DNA sequences may be identified in prostate tissue from many patients . Bacterial detection rates in prostate tissue appear to differ among populations, with higher rates among patients with the chronic prostatitis/pelvic pain syndrome than among those with prostate cancer . Future studies of the role of various bacteria in the prostate may provide insight into the pathophysiology of prostate disease.

J Microbiol Methods, 2000 Jul, 41(2), 85 - 112
Fluorescence in situ hybridization (FISH) for direct visualization of microorganisms; Moter A et al.; As a technique allowing simultaneous visualization, identification, enumeration and localization of individual microbial cells, fluorescence in situ hybridization (FISH) is useful for many applications in all fields of microbiology . FISH not only allows the detection of culturable microorganisms, but also of yet-to-be cultured (so-called unculturable) organisms, and can therefore help in understanding complex microbial communities . In this review, methodological aspects, as well as problems and pitfalls of FISH are discussed in an examination of past, present and future applications.

Anim Reprod Sci, 2000 Nov 1, 63(3-4), 137 - 43
Ureaplasma diversum and reproductive disorder in Brazilian cows and heifers; first report; Cardoso MV et al.; The species Ureaplasma diversum is associated with bovine reproductive illnesses, in particular granular lesions of the vulva and vagina or granular vulvovaginitis (GVV) . In Brazil, this pathology is unknown and, until this point in time, the presence of U . diversum in the Brazilian herds has been ignored . With the intention of detecting the microorganism, vulvovaginal mucuses of 152 animals located on seven farms in the Sao Paulo State, Brazil were analyzed . Those animals had evidence of reproductive disorders at the time of the sample collection . The technique used for microorganism detection was bacterial isolation . Statistical analysis assessed: the exposure of studied farms to U . diversum, relative risks for different symptoms, susceptibility of the animals according to age and breed . The frequency of that microorganism in tested animals was 38.8% and this frequency suggests that U . diversum can be related to GVV in Brazilian herds and possibly with other reproductive illnesses . As a result, the U . diversum differential diagnosis could be very important.

Pharmacol Toxicol, 2000 Jul, 87(1), 46 - 51
Supernatants from macrophages stimulated with microcystin-LR induce electrogenic intestinal response in rabbit ileum; Rocha MF et al.; Microcystin-LR is a cyclic heptapeptide hepatotoxin produced by the cyanobacterium Microcystis aeruginosa . This microorganism often forms toxic blooms in freshwater lakes and reservoirs for drinking water supply, producing serious disorders in humans and animals . Some have suggested that certain biological activities of microcystin may depend upon the stimulation of immune cells . Therefore, the aims of this research were to examine electrogenic intestinal secretion, in vitro, caused by the supernatants from macrophages stimulated with microcystin-LR, as well as to investigate the presence of interleukin-1beta and tumour necrosis factor-alpha in these supernatants . We found that the supernatants of macrophages stimulated with microcystin-LR (0.1, 0.3 and 1.0 microg/ml) caused electrogenic intestinal effects (change in short circuit currents (delta SCC)=57.6, 50.8 and 73.3, respectively, versus control=19.6 microA.cm(-2)) in a time-dependent way (microcystin-LR (1.0 microg/ml)=63.2, 108.8, 120.4 and 132.3 microA.cm(-2) at time 0, 40, 50 and 60 min., respectively) . In addition, the intestinal secretory activity present in these supernatants was blocked (57%) by the prior treatment of macrophages with dexamethasone . We also demonstrated that microcystin-LR (0.1, 0.3 and 1.0 ,microg/ml) is capable of stimulating the synthesis of tumour necrosis factor-alpha (375.4, 369.0 and 610.8 pg/ml, respectively, versus control=165.0 pg/ml) and interleukin-1beta (198.9, 189.3 and 522.1 pg/ml, respectively, versus control=39.7 pg/ml) . These findings demonstrate that microcystin-LR induces the release of interleukin-1beta and tumour necrosis factor-alpha by peritoneal macrophages in vitro, and that the supernatants from these macrophages induce electrogenic secretion in rabbit ileal mucosa.

Mol Biotechnol, 2000 Jul, 15(3), 211 - 23
Problems posed by natural environments for monitoring microorganisms; Edwards C; Microorganisms in natural environments have evolved to withstand fluctuations in physical and chemical conditions . This means that they often manifest very different biochemical and morphological features compared with those seen during laboratory culture . A major limitation in natural ecosystems is nutrient limitation under which microorganisms are exposed to starvation conditions and grow slowly or not at all . This review identifies the role of inimical processes on microbial properties such as the responses to starvation that may result in the adoption of viable but nonculturable (VBNC) states, discusses the problems that altered physiological states pose for detection and identification and highlights novel methods that have been developed to circumvent these difficulties . These factors dictate that to survive and respond to environmental stimuli, a cell must have evolved sophisticated programs of gene expression . These include the sigma factor rpoS that directs RNA polymerase to transcribe genes whose expression aids survival during severe nutrient limitation or cell-cell communication systems that promote a concerted population response termed quorum sensing.

J Immunol Methods, 2000 Sep 21, 243(1-2), 229 - 42
Phagocytosis: measurement by flow cytometry; Lehmann AK et al.; Defects in phagocyte function or in the interactions between phagocytes, microorganisms and serum factors are associated with increased susceptibility to infection . Flow cytometry (FCM) offers rapid and reproducible measurements of single cells in suspension and, following staining with one or more fluorochromes, simultaneous biochemical and functional examinations of the complex process of phagocytosis . FCM techniques have been used for more than two decades to evaluate phagocyte cellular defects, as well as species-specific serum opsonic activities during disease and after vaccination . Recently, multiparameter assays have been developed to reveal the antigen-specificity of opsonophagocytic responses . This review presents basic methodological principles of FCM quantitation of phagocytosis and intracellular oxidative burst, and assays to evaluate species-specific and antigen-specific opsonophagocytosis . The calculations performed to present opsonophagocytosis results, as well as technical and methodological challenges are discussed, and examples of applications are presented.

J Immunol Methods, 2000 Sep 21, 243(1-2), 211 - 27
Flow cytometric screening of cell-based libraries; Daugherty PS et al.; Flow cytometry is a powerful, high-throughput library screening tool in numerous applications including the isolation of bioactive molecules from synthetic combinatorial libraries, the identification of virulence genes in microorganisms, and the study and engineering of protein functions . Using flow cytometry, large libraries of protein mutants expressed in microorganisms can be screened quantitatively for desired functions, including ligand binding, catalysis, expression level, and stability . Rare target cells, occurring at frequencies below 10(-6), can be detected and isolated from heterogeneous library populations using one or more cycles of cell sorting and amplification by growth . Flow cytometry is particularly powerful because it provides the unique opportunity to observe and quantitatively optimize the screening process . However, the ability to isolate cells occurring at such low frequencies within a population requires consideration and optimization of screening parameters . With this aim, an analysis of the various parameters involved in screening cell-based libraries for rare target cells possessing a desired trait is presented.

Rev Enferm, 2000 Jul-Aug, 23(7-8), 537 - 41
{Antiseptics}; Salas Campos L et al.; Antiseptics are chemical products which are applied on live tissues in order to eliminate microorganisms potentially pathogenic, or to inhibit their growth . The selection of the antiseptic must be done according to the properties and the recommended uses of the product . This article describes the main antiseptics used in the clinical practice, paying attention to its range of activity, recommended uses and toxicity.

Am J Ind Med, 2000 Oct, 38(4), 426 - 30
Worker exposures to airborne dust, endotoxin and beta(1,3)-glucan in two New Zealand sawmills; Douwes J et al.; BACKGROUND: Sawmill workers have an increased risk of developing occupational asthma and other respiratory symptoms . Wood dust and microorganisms have both been suggested to play a role, but few studies have measured microbial exposure levels in sawmills . METHODS: The preliminary study reported in this paper assessed airborne dust, bacterial endotoxin and beta(1,3)-glucan levels in 37 samples from two New Zealand sawmills . RESULTS: Nearly one-third of the measured dust levels exceeded 1 mg/m(3) and only one sample exceeded the legal limit of 5 mg/m(3) . Endotoxin levels were clearly elevated with 50% of all measured exposures above 50 EU/m(3) (range: 7-588 EU/m(3)) . beta(1,3)-glucan levels were comparable with levels measured in other industries where workers are exposed to organic dust . Workers in the planing department had the highest mean exposures to dust, endotoxin and beta(1,3)-glucan . Dust levels were only weakly correlated with endotoxin and beta(1,3)-glucan levels . CONCLUSIONS: Endotoxin exposures in sawmill workers are at levels sufficient to potentially contribute to the development of respiratory symptoms . Moreover, measurement of dust exposure is a poor proxy for beta(1,3)-glucan and endotoxin exposure in sawmill workers .

Curr Gastroenterol Rep, 1999 Jun, 1(3), 238 - 44
New causes and treatments for infectious diarrhea in children; Rudolph JA et al.; Infectious diarrhea is a universal and important health problem in the pediatric population . An expanding number of potential viral, bacterial, and parasitic pathogens have been associated with diarrheal disease . However, the epidemiologic association of a microorganism with diarrhea is only one step in the process of identifying new pathogens . Once the virulence mechanisms of these organisms are elucidated, a causal relationship can be more readily defined . This article reviews the etiologic agents of diarrhea in the pediatric population and focuses on the newer treatment and prevention modalities, including probiotics and vaccinations, which are used increasingly to combat these diseases.

Strabismus, 2000 Jun, 8(2), 101 - 11
Thyroid-associated eye disease; Heufelder AE et al.; Graves' ophthalmopathy (GO) is thought to result from a complex interplay of genetic and environmental factors . Various genes, including those coding for HLA, may determine a patient's susceptibility to the disease and its severity, but in addition, numerous and often unknown environmental factors may determine its course . Once established, the chronic inflammatory process within the orbital tissues appears to take on a momentum of its own . Based upon our current state of knowledge, we propose the working scheme shown in Fig . 1 for the pathogenesis of GO: Against the background of a permissive immunogenetic milieu, circulating T cells in patients with Graves' Disease (GD), directed against certain antigens on thyroid follicular cells, recognize antigenic epitopes that are shared by tissues contained in the orbital space . Here, preadipocytes and fibroblasts most likely act as target and effector cells of the orbital immune process . This includes preadipocyte fibroblasts present in the perimysium of extraocular muscles, which do not appear to be immunologically or metabolically different from those located in the orbital connective tissue . Differentiation of orbital preadipocyte fibroblasts into mature adipocytes expressing increased levels of TSHR may be driven by stimulation with circulating or locally produced cytokines or effectors . To date, it is still unknown how autoreactive T cells escape deletion by the immune system and become directed against a self-antigen that is presented by cells residing in the thyroid gland and in certain extrathyroidal locations . Mimicry of a host antigen by a microorganism or presentation of an altered self-antigen may promote proliferation and expansion of autoreactive T cell clones . T cell recruitment into the orbital tissues is facilitated by certain chemokines and cytokines, which help to attract T cells by stimulating the expression of several adhesion molecules (e.g . ICAM-1, VCAM-1, CD44) in vascular endothelium and connective tissue cells . Adhesion molecules are known to be important for a variety of interactions between immunocompetent cells, connective tissue cells and extracellular matrix components . In addition, these molecules play a central role in lymphocyte activation and localization, facilitating antigen recognition, T cell costimulation, and various effector-target cell functions at the inflammatory sites, many of which result in amplification of the cellular immune process in active GO . Analysis of variable region genes of T cell antigen receptors in orbital T cells of patients with active GO has revealed limited variability of TcR V gene usage, suggesting that antigen-driven selection and/or expansion of specific T cells may occur during the early stages of GO . T cells and macrophages populate the orbital space and release a number of cytokines (most likely a Th-1-type spectrum) into the surrounding tissues . Cytokines, oxygen free radicals and fibrogenic growth factors, released both from infiltrating inflammatory and residential cells, act upon orbital preadipocytes in a paracrine and autocrine manner to stimulate adipogenesis, fibroblast proliferation, glycosaminoglycan synthesis, and the expression of immunomodulatory molecules . Smoking, a well-known aggravating factor in GO with an uncertain mode of action, may aggravate tissue hypoxia and exert important immunomodulatory effects . Finally, the long-held hypothesis of a thyroid cross-reactive antigen within the orbital tissues has recently gained significant support from an animal model of ophthalmopathy, and from in vitro and ex vivo studies . If confirmed by immunological studies, these data may well explain the localized infiltration of the orbital tissues by autoreactive lymphocytes that share intriguing molecular features with intrathyroidal lymphocytes . Local release of certain cytokines, TSHR-directed autoantibodies, or other factors might further enhance adipogenesis, glycosaminoglycan synthesis and expression of

J Antimicrob Chemother, 2000 Sep, 46(3), 351 - 62
Selective digestive decontamination in patients in intensive care . The Dutch Working Group on Antibiotic Policy; Bonten MJ et al.; Selective digestive decontamination (SDD) is the most extensively studied method for the prevention of infection in patients in intensive care units (ICUs) . Despite 27 prospective randomized studies and six meta-analyses, routine use of SDD is still controversial . In this review, we summarize the available scientific information on effectiveness of SDD in ICU patients . The effects of SDD have been studied in different combinations of the concept, using different antibiotics . Comparison of the individual studies, therefore, is difficult . In most studies, SDD resulted in significant reductions in the number of diagnoses of ventilator-associated pneumonia . However, incidences of ventilator-associated pneumonia in control groups ranged from 5% to 85% . Moreover, these reductions in incidences of ventilator-associated pneumonia in individual studies were not associated with improved patient survival, reductions of duration of ventilation or ICU stay, or reductions in antibiotic use . The numbers of patients studied are too small to determine effects on patient survival . Although two meta-analyses suggested a 20% mortality reduction when using the full concept of SDD (topical and systemic prophylaxis) these results should be interpreted with caution . Formal cost-benefit analyses of SDD have not been performed . SDD is associated with the selection of microorganisms that are intrinsically resistant to the antibiotics used . However, the studies are too small and too short to investigate whether SDD will lead to development of antibiotic resistance . As long as the benefits of SDD (better patient survival, reduction in antibiotic use or improved cost-effectiveness) have not been firmly established, the routine use of SDD for mechanically ventilated patients is not advised.

FEMS Microbiol Rev, 2000 Oct, 24(4), 429 - 48
Current and future applications of flow cytometry in aquatic microbiology; Vives-Rego J et al.; Flow cytometry has become a valuable tool in aquatic and environmental microbiology that combines direct and rapid assays to determine numbers, cell size distribution and additional biochemical and physiological characteristics of individual cells, revealing the heterogeneity present in a population or community . Flow cytometry exhibits three unique technical properties of high potential to study the microbiology of aquatic systems: (i) its tremendous velocity to obtain and process data; (ii) the sorting capacity of some cytometers, which allows the transfer of specific populations or even single cells to a determined location, thus allowing further physical, chemical, biological or molecular analysis; and (iii) high-speed multiparametric data acquisition and multivariate data analysis . Flow cytometry is now commonly used in aquatic microbiology, although the application of cell sorting to microbial ecology and quantification of heterotrophic nanoflagellates and viruses is still under development . The recent development of laser scanning cytometry also provides a new way to further analyse sorted cells or cells recovered on filter membranes or slides . The main infrastructure limitations of flow cytometry are: cost, need for skilled and well-trained operators, and adequate refrigeration systems for high-powered lasers and cell sorters . The selection and obtaining of the optimal fluorochromes, control microorganisms and validations for a specific application may sometimes be difficult to accomplish.

Diagn Mol Pathol, 2000 Sep, 9(3), 172 - 6
Mismatch cleavage detects pathogenic microorganisms; Hsu IC et al.; When a DNA probe hybridizes a DNA target and generates a G/A mismatch in the probe-target DNA heteroduplex, the mismatch enzyme, mutY, will cut the A base at the site of the mismatch . This specific cleavage at the mismatched A on the known probe will reveal the complementary DNA sequences of the targets . This study shows mismatch cleavage assays identify the complementary sequence of cryptic plasmid target in the extract of chlamydia infected cells in culture . In addition, the specific cleavage at a single base permits differentiation of two sequences with one base difference . This was shown in differentiating the subtypes of human immunodeficiency virus (HIV) type 1 . The addition of amines in the assays increases the sensitivity by freeing the target for recycling . The combined assay system of high sensitivity and demonstrated specificity allows further evaluation for direct identification of pathogenic microorganisms in patient samples.

Dig Liver Dis, 2000 Jan-Feb, 32(1), 34 - 8
Severe acute gastritis associated with Helicobacter pylori infection; Caletti G et al.; We describe the case of a young female referred to our unit because of acute upper abdominal symptoms . Upper gastrointestinal endoscopy showed a gastric picture resembling lymphoma or acute non-steroidal anti-inflammatory drug gastropathy (deep, large and irregular ulcers), but the clinical history and the histological examination of gastric biopsies were consistent only with acute gastritis Helicobacter pylori-correlated . The patient was treated with omeprazole and antibiotics with complete recovery . As the patient's cat had suffered from an acute gastrointestinal distress two weeks earlier, a case of zoonosis was hypothesized and an upper gastrointestinal endoscopy was performed also on the cat . Unfortunately, we were not able to detect Helicobacter pylori in the cat gastric mucosa, but only urease-producing spiral microorganisms . Possible sources of infection and pathogenetic mechanisms of the severe gastritis are discussed.

Chang Gung Med J, 2000 Jul, 23(7), 432 - 7
Inflammatory pseudotumor of the liver mimicking a malignancy: case report; Wei KL et al.; Inflammatory pseudotumor (IPT) is a rare lesion of the liver that can be clinically indistinguishable from a malignant tumor . A 51-year-old woman was hospitalized for upper abdominal pain and a weight loss of 5 Kg in 2 months . Radiological examination showed a large heterogenous hypervascular mass in the left lobe of her liver, strongly in favor of hepatocellular carcinoma . However, an ultrasound-guided liver biopsy revealed the typical characteristics of IPT, which consist of plump spindle cells with dense inflammatory cell infiltration . A left lobectomy was performed . No microorganisms were found on stained sections . The markedly elevated eosinophil count reverted to normal postoperatively and she remained well on follow-up examination 8 months after discharge . This case exemplifies the difficulty in radiological diagnosis of hepatic IPT and underscores the importance of its histological differentiation from malignancy before laparotomy.

Acta Cient Venez, 2000, 51(1), 18 - 26
Disruption of the intestinal barrier and bacterial translocation in an experimental model of intestinal obstruction; Antequera R et al.; Clinical evidence and the use of experimental models in laboratory animals indicate that the intestine is a reservoir of microorganisms that can cause systemic infection in the human . The purpose of this work was to study the possible effect of intestinal obstruction (IO) on the mechanical and chemical barriers that bring protection against microorganisms crossing from the intestinal lumen towards the systemic tissues . We demonstrated that 24 hours after IO, histological and ultrastructural alterations do occur, seriously compromising the structure of the intestinal barrier in 100% of the studied animals . Likewise, it was observed that during the same period, microorganisms translocation from intestine to the peritoneal cavity and liver (100 and 80% respectively) occurred . The lungs were spared . Changes observed in the intestinal epithelium are related to a process similar to that produced by intestinal ischemia: mitochondrial destruction, with subsequent decrease of its capacity to supply energy and to preserve the equilibrium and structure of the intestinal epithelium . We propose that translocation of enteric bacteria may be the cause of the infection that brings about the death a significant group of animals at 48 hours (27%) and 72 hours (33%) post-IO.

Diagn Microbiol Infect Dis, 2000 Aug, 37(4), 247 - 51
Early detection of Leishmania promastigotes in dog bone marrow cultures by acridine orange stain; Barreca GS et al.; An acridine orange staining technique was evaluated in comparison with other well-known methods for the laboratory diagnosis of leishmaniasis . A higher number of promastigotes was found in Novy-MacNeal-Nicolle (NNN) cultures inoculated with canine bone marrow, when culture samples were stained with acridine orange vital stain, compared with those detected using either Giemsa staining or unstained wet mount examination . Based on our data the acridine orange stain is a useful and timely technique in reflecting the true numbers of microorganisms present in a culture and also enhances the visualization of the parasites . The present results warrant further studies with human samples from suspected leishmaniasis patients.

Microbiol Mol Biol Rev, 2000 Sep, 64(3), 573 - 606
Search and discovery strategies for biotechnology: the paradigm shift; Bull AT et al.; Profound changes are occurring in the strategies that biotechnology-based industries are deploying in the search for exploitable biology and to discover new products and develop new or improved processes . The advances that have been made in the past decade in areas such as combinatorial chemistry, combinatorial biosynthesis, metabolic pathway engineering, gene shuffling, and directed evolution of proteins have caused some companies to consider withdrawing from natural product screening . In this review we examine the paradigm shift from traditional biology to bioinformatics that is revolutionizing exploitable biology . We conclude that the reinvigorated means of detecting novel organisms, novel chemical structures, and novel biocatalytic activities will ensure that natural products will continue to be a primary resource for biotechnology . The paradigm shift has been driven by a convergence of complementary technologies, exemplified by DNA sequencing and amplification, genome sequencing and annotation, proteome analysis, and phenotypic inventorying, resulting in the establishment of huge databases that can be mined in order to generate useful knowledge such as the identity and characterization of organisms and the identity of biotechnology targets . Concurrently there have been major advances in understanding the extent of microbial diversity, how uncultured organisms might be grown, and how expression of the metabolic potential of microorganisms can be maximized . The integration of information from complementary databases presents a significant challenge . Such integration should facilitate answers to complex questions involving sequence, biochemical, physiological, taxonomic, and ecological information of the sort posed in exploitable biology . The paradigm shift which we discuss is not absolute in the sense that it will replace established microbiology; rather, it reinforces our view that innovative microbiology is essential for releasing the potential of microbial diversity for biotechnology penetration throughout industry . Various of these issues are considered with reference to deep-sea microbiology and biotechnology.

J Biol Chem, 2000 Nov 24, 275(47), 36734 - 40
Differential activation of four specific MAPK pathways by distinct elicitors; Cardinale F et al.; Plant cells respond to elicitors by inducing a variety of defense responses . Some of these reactions are dependent on the activity of protein kinases . Recently, mitogen-activated protein kinases (MAPKs) have been identified to be activated by fungal and bacterial elicitors as well as by pathogen infection . In gel kinase assays of alfalfa cells treated with yeast cell wall-derived elicitor (YE) revealed that 44- and 46-kDa MAPKs are rapidly and transiently activated . Immunokinase assays with specific MAPK antibodies revealed that YE mainly activated the 46-kDa SIMK and the 44-kDa MMK3 and to a lesser extent the 44-kDa MMK2 and SAMK . When cells were treated with chemically defined elicitors potentially contained in the YE (chitin and N-acetylglucosamine oligomers, beta-glucan, and ergosterol), the four MAPKs were found to be activated to different levels and with different kinetics . Whereas SIMK and SAMK have been found to be activated by a number of diverse stimuli, MMK3 is activated during mitosis and was therefore assumed to participate in cell division () . No physiological process could be associated with MMK2 activity so far . This is the first report that MMK2 and MMK3 can be activated by external stimuli . Overall, our findings indicate that plant cells can sense different cues of a given microorganism through the activation of multiple MAPKs.

Braz J Med Biol Res, 2000 Sep, 33(9), 1023 - 6
Detection of Mycoplasma pneumoniae and Chlamydia pneumoniae in ruptured atherosclerotic plaques; Higuchi ML et al.; This paper reports what is apparently the first observation of Mycoplasma pneumoniae in association with Chlamydia pneumoniae in thrombosed ruptured atheromas . We performed electron microscopy and in situ hybridization in specimens from three patients who died of acute myocardial infarction . These patients had typical symptoms of acute ischemic syndrome . Mycoplasmas were present mainly in the lipid core of the ruptured thrombosed plaque . Vulnerable atheromas are rich in cholesterol and may favor the growth of mycoplasmas, the only microorganisms that require cholesterol for survival . We suggest that the association of Mycoplasma pneumoniae and Chlamydia pneumoniae may increase the virulence of these microorganisms, favoring proliferation, plaque inflammation and possibly plaque rupture.

J Oral Pathol Med, 2000 Sep, 29(8), 394 - 402
Oral mucosal Langerhans' cells as target, effector and vector in HIV infection; Chou LL et al.; The mechanism underlying a transition of the oral cavity mucosal epithelium towards susceptibility to opportunistic infections in HIV-seropositive patients was investigated . Phenotypic markers CD1a, HLA-DR, and CD86 of oral mucosal Langerhans' cells (LCs), p17 core protein of human immunodeficiency virus (HIV), and CD45RO of memory T cells were labeled on oral hairy leukoplakia lesional biopsies and clinically normal autologous tissue of HIV-infected patients . HIV p17 protein was detected in association with mucosal LCs, mainly within the lesional epithelium . There were significant correlations between the detection of HIV p17 and the depletion of LCs, and between the depletion of LCs and the presence of hairy leukoplakia lesions . Conjugates of activated LCs and memory T cells were also evident in the submucosal area of lesional biopsies . The findings from this study support the hypothesis that oral mucosal LCs are also the target of HIV infection . Cytopathic changes of LCs caused by productive HIV infection may contribute to selective depletion of LCs, which may impair the mucosal immunologic protection against colonization by microorganisms causing HIV-associated oral mucosal lesions.

PDA J Pharm Sci Technol, 2000 Jul-Aug, 54(4), 320 - 31
Enumeration of total viable microorganisms in an antibiotic raw material using ChemScan solid phase cytometer; Ramond B et al.; A preliminary study was performed for the enumeration of microorganism contamination of the macrolide antibiotic, Spiramycin, using epifluorescence with the ChemScan solid phase cytometer . The artificial spiking of Spiramycin powder antibiotic with pure culture of four microorganisms led to complete recovery of the tested organisms, whatever their sensitivity to the bacteriostatic activity of the drug . With the conventional plate method run in parallel, complete recovery was only obtained for Spiramycin resistant organisms . The spiked microorganisms that were sensitive to the antibiotic remained inhibited or stressed by the action of the Spiramycin and did not grow on the plate.

PDA J Pharm Sci Technol, 2000 Jul-Aug, 54(4), 305 - 14
Pharmaceutical container/closure integrity . VI: A report on the utility of liquid tracer methods for evaluating the microbial barrier properties of pharmaceutical packaging; Kirsch LE; The relationship between a liquid tracer package leak test (Mg ion ingress) and microbial immersion challenge test was demonstrated by direct and indirect correlation techniques . Rubber-stoppered glass vials with micropipette leaks were evaluated by a helium leak rate method, filled with broth, sterilized, and immersed in a bath containing microorganisms (E . coli/B . diminuta) and liquid tracer (Mg ions) . After exposure and incubation, each unit was evaluated for liquid tracer ingress by atomic absorption spectrophotometry and for microbial ingress by visual inspection and blood agar streaking . Two hundred and eighty sterile broth-filled test units were challenged with microorganisms and liquid tracer . One hundred and fourteen units showed neither liquid tracer nor microbial ingress . One hundred and eight units were positive for both microbial and liquid tracer ingress . No test units were positive for microbial ingress but not for liquid tracer ingress . Fifty-eight units were positive for liquid tracer ingress but failed to show microbial ingress . Logistical regression was used to demonstrate that the probability of liquid tracer ingress was greater than microbial ingress at all leak sizes . The results indicate that the liquid tracer method studied herein was a useful indicator of the microbial barrier properties of pharmaceutical packaging . Additionally, the results support the contention that liquid penetration of a leak is required for microbial ingress.

Semin Diagn Pathol, 2000 Aug, 17(3), 170 - 7
Advances in immunohistochemistry: impact on surgical pathology practice; Chan JK; Over the past decade, the many advances in immunohistochemical techniques have revolutionized the field of immunohistochemistry . Most notable is discovery of the use of heat for antigen retrieval, which permits consistent and reliable demonstration of antigens in routine surgical pathology specimens despite variations in the duration of fixation and tissue processing schedules . As a result, immunohistochemical studies play an increasingly important role in surgical pathology, such as help in rendering a diagnosis in a crushed specimen, classification of tumors, prediction of the likely origin of a carcinoma, demonstration of micrometastases, provision of prognostic information, and demonstration of microorganisms . To serve such purposes, immunohistochemical stains must be performed at a high standard with consistent and reproducible results . The stains must be interpreted cautiously in the appropriate context, and potential pitfalls such as endogenous biotin activity must be recognized . The increased demand for immunohistochemical tests raises the issue of cost containment, which can be achieved through a number of ways, such as deletion of nonvalue-added tests, deletion of antibodies that no longer serve a purpose, replacement of the conventional positive control with a multitissue control mounted on the same slides of the test cases, various means of savings on antibodies, and continuing to use "expired" antibodies . To keep abreast of modem developments in the field in this era of information explosion, the internet can play an important role by providing updated information or database and a platform for rapid exchange of knowledge.

Int Arch Occup Environ Health, 2000 Jun, 73 Suppl, S69 - 74
Natural organic fibers--health effects; Jarvholm B; OBJECTIVES: Natural organic fibers are used in large quantities in the production of paper products and textiles . They are also constituents of food and added to food to promote health . The objective of this review is to evaluate the health effects of natural organic fibers . The health effects of dietary fibers are excluded from the review . METHODS: This is a literature review . RESULTS: Exposure to these fibers in industry is usually not characterized as fibers but as dust . Rather dusty conditions have been reported in both paper and textile industries with concentrations up to and above 30 mg/m3 . Both in the paper and textile industry inorganic fibers may occur making it hard to evaluate health effects of natural organic fibers from studies of workers in the paper and textile industry . There seems to be no increased risk of mesothelioma, lung cancer or lung fibrosis in workers exposed to natural organic fibers in contrast to workers exposed to inorganic crystalline fibers as asbestos . However, workers with a heavy exposure to paper dust or textile dust seem to have an increased risk of obstructive lung disease and bronchitis . These effects have not been causally linked to the fibrous shape of the particles but rather to the dust, chemicals absorbed on the dust or microorganisms occurring together with the dust . There is some indication that work in the textile industry may increase the risk of sinonasal cancer, but the etiological agents are unknown . CONCLUSION: Natural organic fibers are not causally linked with the well-known effects of some inorganic fibers, i.e . mesothelioma, lung cancer, lung fibrosis or some pleural diseases . The health effects of natural organic fibers, e.g . irritative effects, seem not to be linked to their fibrous shape.

Life Sci, 2000 Jul 7, 67(7), 733 - 42
The biology of ophiobolins; Au TK et al.; This review article aims at summarizing the research findings on the biological aspects of ophiobolins, phytotoxins produced by the pathogenic fungi Bipolaris species, which usually infect rice, maize and sorghum . The topics covered include the organisms that produce the various ophiobolins, the structural variations of ophiobolins, the biological actions of ophiobolins in plants, animals and microorganisms, and the mode of action and the possible use of ophiobolin A as a calmodulin antagonist.

Crit Rev Immunol, 2000, 20(3), 197 - 222
Regulation of the adhesion versus cytotoxic functions of the Mac-1/CR3/alphaMbeta2-integrin glycoprotein; Ross GD; Mac-1/CR3 functions as both an adhesion molecule mediating the diapedesis of leukocytes across the endothelium and a receptor for the iC3b fragment of complement responsible for phagocytic/degranulation responses to microorganisms . Mac-1/CR3 has many functional characteristics shared with other integrins, including bidirectional signaling via conformational changes that originate in either the cytoplasmic domain or extracellular region . Another key to its functions is its ability to form membrane complexes with glycosylphosphatidylinositol (GPI)-anchored receptors such as Fc gammaRIIIB (CD16b) or uPAR (CD87), providing a transmembrane signaling mechanism for these outer membrane bound receptors that allows them to mediate cytoskeleton-dependent adhesion or phagocytosis and degranulation . Many functions appear to depend upon a membrane-proximal lectin site responsible for recognition of either microbial surface polysaccharides or GPI-linked signaling partners . Because of the importance of Mac-1/CR3 in promoting neutrophil inflammatory responses, therapeutic strategies to antagonize its functions have shown promise in treating both autoimmune diseases and ischemia/reperfusion injury . Conversely, soluble beta-glucan polysaccharides that bind to its lectin site prime the Mac-1/CR3 of circulating phagocytes and natural killer (NK) cells, permitting cytotoxic degranulation in response to iC3b-opsonized tumor cells that otherwise escape from this mechanism of cell-mediated cytotoxicity.

Microbes Infect, 2000 Jul, 2(9), 1119 - 24
Molecular studies of the intestinal mucosal barrier physiopathology using cocultures of epithelial and immune cells: a technical update; Kerneis S et al.; Peyer's patch lymphocytes cocultured with Caco-2 cells trigger the phenotypic conversion of enterocytes into cells that express morphological and functional M-cell properties . We report a technical update for setting up this model, which will enable the study of M-cell biology, the identification by biochemical approaches of molecules involved in the interaction of microorganisms with M cells, and the development of vectors that would efficiently target the mucosal immune system.

Front Biosci, 2000 Sep 01, 5, D787 - 95
Protein stability in extremophilic archaea; Scandurra R et al.; Extremophilic microorganisms have adapted their molecular machinery to grow and thrive under the most adverse environmental conditions . These microorganisms have found their natural habitat at the boiling and freezing point of water, in high salt concentration and at extreme pH values . The extremophilic proteins, selected by Nature to withstand this evolutionary pressure, represent a wide research field for scientists from different disciplines and the study of the determinants of their stability has been an important task for basic and applied research . A surprising conclusion emerges from these studies: there are no general rules to achieve protein stabilization . Each extremophilic protein adopts various strategies and the outstanding adaptation to extreme temperature and solvent conditions is realized through the same weak electrostatic and hydrophobic interactions among the ordinary amino acid residues which are also responsible for the proper balance between protein stability and flexibility in mesophilic proteins.

FEMS Microbiol Ecol, 2000 Aug 1, 33(2), 89 - 99
Bacteria in the cold deep-sea benthic boundary layer and sediment-water interface of the NE Atlantic; Turley C; This is a short review of the current understanding of the role of microorganisms in the biogeochemistry in the deep-sea benthic boundary layer (BBL) and sediment-water interface (SWI) of the NE Atlantic, the gaps in our knowledge and some suggestions of future directions . The BBL is the layer of water, often tens of meters thick, adjacent to the sea bed and with homogenous properties of temperature and salinity, which sometimes contains resuspended detrital particles . The SWI is the bioreactive interface between the water column and the upper 1 cm of sediment and can include a large layer of detrital material composed of aggregates that have sedimented from the upper mixed layer of the ocean . This material is biologically transformed, over a wide range of time scales, eventually forming the sedimentary record . To understand the microbial ecology of deep-sea bacteria, we need to appreciate the food supply in the upper ocean, its packaging, passage and transformation during the delivery to the sea bed, the seasonality of variability of the supply and the environmental conditions under which the deep-sea bacteria grow . We also need to put into a microbial context recent geochemical findings of vast reservoirs of intrinsically labile organic material sorped onto sediments . These may well become desorped, and once again available to microorganisms, during resuspension events caused by deep ocean currents . As biotechnologists apply their tools in the deep oceans in search of unique bacteria, an increasing knowledge and understanding of the natural processes undertaken and environmental conditions experienced by deep-sea bacteria will facilitate this exploitation.

Proteins, 2000 Nov 1, 41(2), 257 - 69
Comparative modeling of the three-dimensional structures of family 3 glycoside hydrolases; Harvey AJ et al.; There are approximately 100 known members of the family 3 group of glycoside hydrolases, most of which are classified as beta-glucosidases and originate from microorganisms . The only family 3 glycoside hydrolase for which a three-dimensional structure is available is a beta-glucan exohydrolase from barley . The structural coordinates of the barley enzyme is used here to model representatives from distinct phylogenetic clusters within the family . The majority of family 3 hydrolases have an NH(2)-terminal (alpha/beta)(8) barrel connected by a short linker to a second domain, which adopts an (alpha/beta)(6) sandwich fold . In two bacterial beta-glucosidases, the order of the domains is reversed . The catalytic nucleophile, equivalent to D285 of the barley beta-glucan exohydrolase, is absolutely conserved across the family . It is located on domain 1, in a shallow site pocket near the interface of the domains . The likely catalytic acid in the barley enzyme, E491, is on domain 2 . Although similarly positioned acidic residues are present in closely related members of the family, the equivalent amino acid in more distantly related members is either too far from the active site or absent . In the latter cases, the role of catalytic acid is probably assumed by other acidic amino acids from domain 1.

Annu Rev Biochem, 2000, 69, 1 - 29
Still looking for the Ivory Tower; Schachman HK; Following graduate training, which was disrupted by my changing schools and serving in the Navy in World War II, I arrived in Berkeley in 1948 as an instructor in the Biochemistry Department . Despite numerous academic reorganizations and a host of struggles over the University-imposed Loyalty Oath, dismissal of a faculty member because of political affiliations, free speech for students, and my resistance to mandatory retirement, I survived with the help of great graduate students, postdoctoral fellows, undergraduates, superb research assistants, and a supportive wife . Studies on structure of tobacco mosaic virus led to our investigating an ultracentrifuge anomaly and the construction of a synthetic boundary cell . In turn, this resulted in about 15 years of research on the ultracentrifuge and its application to the study of biological macromolecules . Among the latter, the discovery of large ribonucleoprotein complexes, now known as ribosomes, and chromatophores in photosynthetic microorganisms attracted the most attention . But it was the development of the photoelectric absorption optical system and the incorporation of the Rayleigh interferometer onto the ultracentrifuge that had the greatest impact on our further research . These tools, when applied to our initial research on E . coli aspartate transcarbamoylase (ATCase), led to the discovery of distinct subunits for catalysis and regulation and the global conformational change in the enzyme associated with its role in regulation . For almost 35 years we have been using the techniques of protein chemistry and molecular biology in studies of structural and conformational changes in the enzyme, the genes encoding the different polypeptides, subunit interactions, and assembly of the enzyme from six catalytic and six regulatory chains . Hybrids constructed from inactive mutants were used to demonstrate shared active sites requiring the joint participation of amino acid residues from adjoining polypeptide chains . ATCase is still being studied as a model for understanding allostery as a regulatory mechanism . Circularly permuted polypeptide chains are being used to study the folding and assembly pathways, and the recently determined crystal structure of the active nonallosteric catalytic subunit has led to new questions regarding the activated form of ATCase.

Microbes Infect, 2000 Jul, 2(8), 923 - 31
Molecular mechanisms of invasion by cancer cells, leukocytes and microorganisms; Lauwaet T et al.; Invasion is a phenotype common to cancer cells, leukocytes, parasites, bacteria and viruses, involving cell-cell adhesion, cell-matrix adhesion, proteolysis and motility . These activities are regulated by the cross talk between invaders and host . We discuss the invasion-related molecular interactions of E-cadherin, integrins, matrix metalloproteinases and the chemokine receptor RANTES.

Microbes Infect, 2000 Jul, 2(8), 897 - 906
The oral cavity as a reservoir of bacterial pathogens for focal infections; Gendron R et al.; Dental procedures, but more importantly, oral infections and poor oral health can provoke the introduction of oral microorganisms into the bloodstream or the lymphatic system . The subsequent attachment and multiplication of these bacteria on tissues or organs can lead to focal oral infections . Pathogenic agents may also remain at their primary oral site but the toxins liberated can reach an organ or tissue via the bloodstream and cause metastatic injury . Finally, metastatic inflammation may result from an immunological injury caused by oral bacteria or their soluble products that enter the bloodstream and react with circulating specific antibodies to form macromolecular complexes.

Am J Physiol Gastrointest Liver Physiol, 2000 Sep, 279(3), G492 - 9
Identification of genes involved in mucosal defense and inflammation associated with normal enteric bacteria; Ogawa H et al.; Normal luminal bacteria and their products play a role in experimental colitis and inflammatory bowel disease . However, what molecules from what cells are responsible for mounting and maintaining the mucosal defense against luminal flora is still uncertain . The aim of this study was to identify epithelial gene products involved in mucosal defense and inflammation associated with ubiquitous enteric bacteria . Germ-free ICR mice were given an oral bacterial suspension prepared from conventional components (bacterial reconstitution) . Small intestinal and colonic epithelial cells were isolated from bacteria-reconstituted, germ-free, and specific pathogen-free mice . Differential gene expression was investigated by differential display, Northern blot, and sequence analysis . Bacterial reconstitution resulted in acute but self-limited colitis . In epithelial cells, we observed the induction of small intestine-specific genes of the cryptdin family and colon-specific expression of serum amyloid A1 gene . This novel approach allows the identification of known and novel gene products involved in mucosal defense against luminal microorganisms and the associated inflammatory response.

Scand J Infect Dis, 2000, 32(4), 425 - 6
Difficulties in diagnosing Brucella spondylitis; Jensenius M et al.; We describe a case of culture-proven Brucella spondylitis in a 28-y-old Turkish male asylum seeker who had arrived to Norway 6 months earlier . Several diagnostic difficulties, including rapid in vitro growth and misidentification of the causative microorganism in biochemical gallery strip tests, resulted in late diagnosis.

Neurochem Res, 2000 Jul, 25(7), 903 - 8
Inhibition of microglial nitric oxide production by hydrocortisone and glucocorticoid precursors; Chang JY et al.; Viral and bacterial infection in the central nervous system can induce nitric oxide production, which serves as a major host defense against invading microorganisms . Glucocorticoids secretion is enhanced and immune responses are diminished in stressed animals or in patients suffering depression . Using N9 microglial cells, this study tested the hypothesis that glucocorticoids and their precursors caused an impaired immune defense in animals because these compounds could inhibit microglial nitric oxide production . Results indicated that both hydrocortisone and the synthetic glucocorticoid, dexamethasone, were potent inhibitors of the microglial nitric oxide production . While glucocorticoid precursors were not as potent as hydrocortisone, the potency of these precursors increased linearly as they advanced on the biosynthesis pathway . Northern and Western blot analyses indicated that hydrocortisone and dexamethasone might interfere with the inducible nitric oxide synthase at either the transcription or at the post-translational level, depending on the concentrations used . These results suggest that glucocorticoids have the ability to block nitric oxide production by microgila, which could partially explain the impaired immune protection against infection in the central nervous system in stressed animals.

Vet Res, 2000 Jul-Aug, 31(4), 413 - 35
{Bacterial enterotoxin receptors}; Rousset E et al.; Bacterial enterotoxin receptors . Enteric bacterial toxins display a great diversity in their structure, molecular weight and mechanism of action . The interaction of enterotoxins with the intestinal mucosa either leads to a direct effect on the cell membrane or an effect on signal transduction within eukaryotic cells . However, before a toxin can affect a cell, it must after its secretion by a microorganism, recognise and bind to a specific surface molecule, its receptor . Membrane receptors of bacterial enterotoxins have been identified as protein, glycoprotein or glycolipid in nature . The chemical nature of the molecules acting as receptors is crucial and during evolution they have been carefully selected . Some toxins, after their interaction with a receptor molecule, will transduce a signal across the cell membrane while remaining at the cell surface . Other toxins, after this initial binding step with a receptor, will be internalised . Others can form pores leading to leakage of cellular components and cell lysis . Receptors that have been identified often comprise a saccharidic chain that is directly involved in the recognition and binding of the toxin . Today, models explaining toxin-receptor interactions are more complex, including multistep events . This review summarises the knowledge of the interactions between bacterial toxins and membrane receptors present on intestinal mucosa.

J Basic Microbiol, 2000, 40(3), 177 - 86
Abundance of polymers degrading microorganisms in a sea-based solid waste disposal site; Ishigaki T et al.; In order to assess the degradability of plastics in solid waste disposal landfill sites, microbial populations capable of degrading five kinds of plastic-constituting polymers, poly epsilon-caprolactone (PCL), polylactic acid (PLA), polyethylene glycol (PEG), poly-beta-hydroxybutyrate (PHB) and cellulose acetate (CA), in a sea-based solid waste disposal site were investigated . Enumeration of aerobic and anaerobic polymers-degrading microorganisms (PDMs) was performed against to total 8 leachate samples, which were seasonally collected from the facultative pretreatment pond and the aerated lagoon . Both aerobic and anaerobic PDMs for natural polymers, PHB and CA, were found in all of the samples, while those for chemically-synthesized polymers, PCL, PLA and PEG, could not be always detected . In most cases, the ratios of the PHB- and CA-degraders to the heterotrophic bacterial population were more than 0.1% . On the other hand, the ratios of PCL-, PLA- and PEG-degraders were often much lower . These data indicate that the plastics degradation potential is commonly present in the studied disposal site, and that the degradation potential for plastics composed of chemically-synthesized polymers is inferior to that of natural polymers . Population sizes of the PDMs correlated to those of heterotrophic bacteria, and the counts of aerobic heterotrophic bacteria and PDMs in the aerated lagoon tended to be higher than those of anaerobic ones, indicating that the aeration of the leachate resulted in the activation of growth of whole aerobic microbial community including the PDMs.

J Agric Food Chem, 2000 Aug, 48(8), 3728 - 32
Influence of insecticides on microbial transformation of nitrogen and phosphorus in Typic Orchragualf soil; Das AC et al.; Four insecticides, viz., BHC, phorate, carbofuran, and fenvalerate, were applied at the rate of 7.5, 1.5, 1.0, and 0.35 kg a.i . ha(-)(1), respectively, to investigate their effects on the growth and activities of N(2)-fixing and phosphate-solubilizing microorganisms in relation to the availability of N and P in laterite (Typic Orchragualf) soil . Insecticides in general, and BHC and phorate in particular, stimulated the proliferation of aerobic nonsymbiotic N(2)-fixing bacteria and phosphate-solubilizing microorganisms and also their biochemical activities, such as nonsymbiotic N(2)-fixing and phosphate-solubilizing capacities, which resulted in greater release of available N (NH(4)(+) and NO(3)(-)) and P in soil . All the insecticides were persistent in soil for a short period of time, and the rate of dissipation was highest for fenvalerate followed by phorate, carbofuran, and BHC, depicting the half-lives (T(1/2)) 8.8, 9.7, 16.9, and 20.6 days, respectively . The insecticides followed first-order reaction kinetics during their dissipation in soil.

Vet Q, 2000 Jul, 22(3), 123 - 30
The use of skin delayed-type hypersensitivity as an adjunct test to diagnose brucellosis in cattle: a review; Bercovich Z; Brucellosis, caused by bacteria of the genus Brucella, is a contagious disease that causes economic loss to owners of domestic animals due to loss of progeny and milk yield . Because cattle, sheep, goats, and to a lesser extent pigs are considered to be the source of human brucellosis, serological tests have been used to screen domestic animals for antibodies against Brucella . Although the serological tests helped to eradicate brucellosis in many countries, serological tests are not always adequate to detect latent carriers of Brucella . Therefore, the use of the skin delayed-type hypersensitivity (SDTH) test, which is independent of circulating antibodies, might improve the diagnosis of brucellosis . In the literature, however, there are conflicting reports as to the value of the SDTH test for the diagnosis of brucellosis . Some studies consider the test unreliable, whereas others advocate its use because it detects brucellosis earlier than serological tests . The objectives of this study were therefore to assess the characteristics of the SDTH test, to select a Brucella strain that will yield a suitable brucellin for use in the field, and to determine whether the use of serological tests in combination with the SDTH test improves the detection of brucellosis . The results of this study clearly show that the SDTH test detects latent carriers of Brucella and confirms brucellosis in cattle with ambiguous serological test results . Brucellins prepared from smooth or mucoid strains of Brucella are better suited for use in the field than brucellins prepared from rough strains because they detect brucellosis in cattle with acute as well as chronic infection . The SDTH test is highly specific (99.3% specificity), and repeated testing of naive cattle or cattle infected with microorganisms that serologically cross-react with Brucella does not sensitize cattle to subsequent SDTH tests . However, it is possible that some naive cattle may serologically react to the injection of brucellin . The effect of these serological reactions on the sero-diagnosis of brucellosis is limited, because cattle may only now and then react serologically either with the serum agglutination test (SAT) or the complement fixation test (CFT) . Nevertheless, cattle infected with microorganisms that serologically cross-react with Brucella may test seropositive for brucellosis 4 to 7 weeks after injection of brucellin, depending on the cross-reacting microorganism . The value of the SDTH test for the diagnosis of brucellosis was demonstrated after an outbreak of brucellosis . When the SDTH test was used in combination with SAT and CFT at diagnostic threshold > or =2 mm or > or =1 mm (increase in skinfold thickness), respectively, 39/44 (88%) or 42/44 (95%) of the infected cattle were detected compared with only 27/44 (61%) when SAT and CFT were used . When cattle in areas of low prevalence or in areas free from brucellosis are tested with the SDTH test an increase > or =2 mm in skinfold thickness should be considered indicative of infection . When the control and eradication of brucellosis is based on test-and-slaughter, an increase of > or =1 mm in skinfold thickness should be considered indicative of infection . Repeated serological testing complemented with the SDTH test in this programme will shorten the quarantine (movement control) period of a suspect herd, limiting the financial loss incurred during outbreaks of the disease . Consequently, since the SDTH test usually does not interfere with the serological diagnosis and can safely be used to establish the infection status of cattle in a suspect herd, it is opportune to consider adding the SDTH test to the procedure currently used to diagnose brucellosis in individual animals.

Appl Microbiol Biotechnol, 2000 Jul, 54(1), 1 - 8
Molecular studies on isopenicillin N synthases; Sim TS et al.; The isopenicillin N synthases isolated thus far are related to oxidases from other microorganisms and plants . These enzymes maintain a non-heme monoferrous-dependent catalytic centre comprising a HisXAsp(53-57)XHis motif and a crucial substrate-binding pocket with an ArgXSer motif for their functionality . The elucidation of these motifs was dependent on information collated from studies on structural chemistry, structural biology, site-directed engineered mutations and biochemical experiments . It is envisaged that these enzymes can potentially be improved through molecular breeding and protein engineering.

Allergy Asthma Proc, 2000 Jul-Aug, 21(4), 221 - 5
IgE and the allergy-asthma connection in the 23-year follow-up of Brown University students; Settipane RJ et al.; The Hygiene Hypothesis helps to explain the increased epidemiology of atopy, especially asthma and hay fever . This hypothesis depends on two major immunological pathways, the Th1 and the Th2 pathways, which are mutually inhibitory, with the Th2 pathway being the dominant one in fetal life and the newborn . The Th1 leads to a cellular delayed hypersensitive response while the Th2 pathway leads to increased IgE, eosinophilia, atopy, and airway/hyperresponsiveness . The ever-increasing vaccines for immunization against viral and bacterial microorganisms together with better public health hygiene procedures introduce a bias in favor of the inhibition of the Th1 pathway, thereby allowing the Th2 pathway, with its IgE hypersensitivity, to predominate . We have attempted to correlate this new hypothesis with data from our Brown University college student longitudinal study . In this study, our data have demonstrated that allergen sensitization (positive pollen skin tests reactions) leads to an increased risk factor for developing asthma . Most of our asthmatic patients in our longitudinal study had positive allergy skin tests . Also, students born in months with high concentrations of atmospheric ragweed pollen had an increased risk of developing sensitization to ragweed and later to develop hay fever, which may lead to asthma . There is a strong association of asthma with hay fever (a classic IgE disease) . Also, hay fever patients have three times the risk for developing asthma than controls . There appear to be several factors needed to express the phenotype of allergic asthma: elevated IgE, eosinophilia, airway hyperresponsiveness, exposure to allergens, and the predominance of the Th2 pathway of immunologic reactions.

Rev Neurol, 2000 Jul 16-31, 31(2), 137 - 41
{The history and classification of human prion diseases}; Polo JM; INTRODUCTION AND DEVELOPMENT: The history of prion diseases is one of the most exciting chapters of the story of medicine in the twentieth century . It began in the nineteen twenties when Creutzfeldt (in one patient) and Jakob (in five patients) described a clinically polymorphic cerebral syndrome with a subacute or chronic course and fatal outcome . Although later reviews of these pioneer studies have cast doubt on the nosology of some of these cases, the eponym has been maintained over the years . It is even possible that the miliary sclerosis described by Gowers in the nineteenth century was in fact a spongiform encephalopathy . Subsequently the nosological limits of Creutzfeldt-Jakob disease remained ill-defined . This explains the large number of names given to it whilst it continued to be included in the chapter on degenerative conditions of the nervous system . Perhaps the turning point was when, in the nineteen sixties, Carleton Gajdusek et al showed that it was transmissible . Previously Gajdusek and Zigas had (in 1957) described the disease kuru in a group of indigenous cannibals in Papua (New Guinea) . The possibility of a parallel between this kuru and the scrapie of sheep (in which transmission had been proved twenty years before) led them to experiment and eventually prove its infectious nature . Over the following years, reports of iatrogenic cases with different routes of transmission gave further proof . The absence of conventional microorganisms responsible for this group of conditions led Prusiner (in 1982) to suggest the theory of the infecting proton or prion . CONCLUSION: This theory led to better understanding of several pathological and physiopathological aspects, however, we are aware that the full story of prion diseases is still being written at the present time.

Rev Latinoam Microbiol, 2000 Jan-Mar, 42(1), 27 - 33
Efficacy of florphenicol premix in weanling pigs experimentally infected with Actinobacillus pleuropneumoniae; Palacios-Arriaga JM et al.; The efficacy of a florfenicol premix was studied in weaning pigs experimentally inoculated with Actinobacillus pleuropneumoniae . Twenty five clinically healthy pigs were distributed into 3 groups; group A non-medicated, groups B and C orally medicated with 20 and 40 ppm of florfenicol respectively . The pigs were fed during 12 consecutive days and on day 5 all the groups were challenged with A . pleuropneumoniae serotype 1 . All the animals in Group A developed clinical signs . Most of the pigs in the medicated groups maintained a good health status . Postmortem examination revealed severe pleuropneumonia in pigs from the control group and pneumonic lesions in 40% of the animals treated with 20 ppm of florfenicol . Development of pleuropneumonia was prevented in all the pigs medicated with 40 ppm of florfenicol . Actinobacillus pleuropneumoniae was recovered from the lungs of all control animals and from one pig of each of the medicated groups, however, the avidin biotin peroxidase (ABC-P) method detected the presence of the microorganism in all the animals . We demonstrated that medication with feed containing 40 ppm of florfenicol blocked efficiently the signs and lesions caused by A . pleuropneumoniae and increased the daily body weight gain.

Rev Latinoam Microbiol, 2000 Jan-Mar, 42(1), 7 - 11
{Isolation of Mycoplasma bovis during an outbreak of bovine mastitis at a dairy farm in the province of Buenos Aires . 1st report in the Republic of Argentina}; Cerda R et al.; Several mycoplasma species produce various diseases in different animal species . M . bovis has been described as the cause of mastitis, arthritis, pneumonia and infertility in cattle . Furthermore, this species has been the most frequently isolated agent producing bovine mastitis . The objective of this study was to isolate and typify mycoplasma strains from a clinical mastitis outbreak in a dairy farm of Buenos Aires Province . A total of 279 samples were studied (276 from pooled quarter milk of cows with clinical mastitis that did not respond to antibiotic therapy, 1 from bulk tank milk and 2 preputial swabs from bulls) . The isolated mycoplasma strains (n = 12) were further characterized by biochemical analysis, serological studies and electrophoretic analysis of the protein profiles (SDS-PAGE) . Based upon these studies, the isolated strains were identified as Mycoplasma bovis . This is the first report of isolation of this microorganism in Argentina . Therefore the results described here could be very useful to improve mastitis control in dairy farms.

Rev Latinoam Microbiol, 2000 Jan-Mar, 42(1), 1 - 6
Association of Mycoplasma hominis and Ureaplasma urealyticum with some indicators of nonspecific vaginitis; Cedillo-Ramirez L et al.; The purpose of this study was to determine the isolation rates of Mycoplasma hominis and Ureaplasma urealyticum from three populations of women and also to relate the presence of these microorganisms with some indicators of nonspecific vaginitis . Three hundred vaginal swabs were taken from delivery, pregnant and control (not pregnant) women . Cultures were done in E broth supplemented with arginine or urea . M . hominis was isolated in 5% at delivery, 12% from pregnant and 5% from control women and U . urealyticum was isolated in 21%, 31% and 28% respectively . There was statistical difference in the isolation rate of M . hominis in pregnant women respect to the other groups . Both microorganisms were more frequently isolated in women with acid vaginal pH, amine-like odor in KOH test, clue cells and leucorrhea . M . hominis was isolated in 17% and U . urealyticum in 52% from women with nonspecific vaginitis . M . hominis was isolated in 2% and U . urealyticum in 13% from women without nonspecific vaginitis . Although the presence of clue cells and amine-like odor in KOH test have relationship with Gardnerella vaginalis, these tests could also suggest the presence of these mycoplasmas.

Infect Immun, 2000 Sep, 68(9), 5284 - 92
Cytokine responses to treponema pectinovorum and treponema denticola in human gingival fibroblasts; Nixon CS et al.; Human gingival fibroblasts were challenged with Treponema pectinovorum and Treponema denticola to test three specific hypotheses: (i) these treponemes induce different cytokine profiles from the fibroblasts, (ii) differences in cytokine profiles are observed after challenge with live versus killed treponemes, and (iii) differences in cytokine profiles are noted from different gingival fibroblast cell lines when challenged with these treponemes . Three normal gingival fibroblast cell cultures were challenged with T . pectinovorum and T . denticola strains, and the supernatants were analyzed for cytokine production (i.e., interleukin-1alpha {IL-1alpha}, IL-1beta, IL-6, IL-8, IL-10, gamma interferon, macrophage chemotactic protein 1 {MCP-1}, platelet-derived growth factor, tumor necrosis factor alpha, and granulocyte-macrophage colony-stimulating factor) . Unstimulated fibroblast cell lines produced IL-6, IL-8, and MCP-1 . T . pectinovorum routinely elicited the greatest production of these cytokines from the fibroblast cell lines, increasing 10- to 50-fold over basal production . While T . denticola also induced IL-6 and IL-8 production, these levels were generally lower than those elicited by challenge with T . pectinovorum . MCP-1 levels were significantly lower after T . denticola challenge, and the kinetics suggested that this microorganism actually inhibited basal production by the fibroblasts . No basal or stimulated production of the other cytokines was observed . Significant differences were noted in the responsiveness of the various cell lines with respect to the two species of treponemes and the individual cytokines produced . Finally, dead T . pectinovorum generally induced a twofold-greater level of IL-6 and IL-8 than the live bacteria . These results supported the idea that different species of oral treponemes can elicit proinflammatory cytokine production by gingival cells and that this stimulation did not require live microorganisms . Importantly, a unique difference was noted in the ability of T . pectinovorum to induce a robust MCP-1 production, while T . denticola appeared to inhibit this activity of the fibroblasts . While the general cytokine profiles of the fibroblast cell cultures were similar, significant differences were noted in the quantity of individual cytokines produced, which could relate to individual patient variation in local inflammatory responses in the periodontium.

J Pharm Pharm Sci, 1998 May-Aug, 1(2), 48 - 59
Biotech pharmaceuticals and biotherapy: an overview; Steinberg FM et al.; Broadly, the history of pharmaceutical biotechnology includes Alexander Fleming"s discovery of penicillin in a common mold, in 1928, and the subsequent development-prompted by World War II injuries-of large-scale manufacturing methods to grow the organism in tanks of broth . Pharmaceutical biotechnology has since changed enormously . Two breakthroughs of the late 1970s became the basis of the modern biotech industry: the interspecies transplantation of genetic material, and the fusion of tumor cells and certain leukocytes . The cells resulting from such fusion-hybridomas-replicate endlessly and can be geared to produce specific antibodies in bulk . Modern pharmaceutical biotechnology encompasses gene cloning and recombinant DNA technology . Gene cloning comprises isolating a DNA-molecule segment that corresponds to a single gene and synthesizing ("copying") the segment . Recombinant DNA technology, or gene splicing, comprises altering genetic material outside an organism-for example, by inserting into a DNA molecule a segment from a very different DNA molecule-and making the altered material (recombinant DNA) function in living things . Recombinant DNA technology enables modifying microorganisms, animals, and plants so that they yield medically useful substances, particularly scarce human proteins (by giving animals human genes, for example) . This review, however, focuses not on pharmaceutical biotechnology"s methods but on its products, notably recombinant pharmaceuticals . It describes various types of biotech pharmaceuticals, their safety and effectiveness relative to the safety and effectiveness of conventionally produced pharmaceuticals, and the regulation of biotech pharmaceuticals.

J Food Prot, 2000 Aug, 63(8), 1117 - 22
Efficacy of disinfectants in killing spores of Alicyclobacillus acidoterrestris and performance of media for supporting colony development by survivors; Orr RV et al.; Alicyclobacillus has recently emerged as a spoilage microorganism of concern in a wide range of pasteurized fruit products . The focus of this study was to determine the efficacy of chemical disinfectants in killing Alicyclobacillus acidoterrestris spores . Direct plating media were evaluated for their suitability to support germination and outgrowth of spores surviving exposure to these disinfectants . Significant (P < or = 0.05) reductions of about 2.2, 0.4, and 0.1 logs in the number of viable A . acidoterrestris spores in a five-strain mixture were achieved when spores were suspended in 200 ppm chlorine, 500 ppm acidified sodium chlorite, or 0.2% H2O2 solutions, respectively, for 10 min at 23 degrees C . When treated with either 1,000 ppm chlorine or 4% H2O2, the number of spores was reduced by more than 5 logs . Treatment with 8% trisodium phosphate or 80 ppm Tsunami did not significantly reduce numbers of viable spores . Spores of individual strains of A . acidoterrestris varied little in resistance to the same chemical treatment . K agar (pH 3.7) was judged best for recovering chemically treated spores, compared to orange serum agar (pH 5.0) and potato dextrose agar (pH 3.5) . Experiments were done to determine the effectiveness of chemical treatments in killing a mixed-strain inoculum of A . acidoterrestris spores on the surface of apples . Treatment with 500 ppm chlorine or 1,200 ppm acidified sodium chlorite for 1 min significantly (P < or = 0.05) reduced the number of viable spores, but reductions were less than 1 log . Hydrogen peroxide (2%) was ineffective in killing spores remaining on the apple skin after treatment.

Biosens Bioelectron, 2000 Jan, 14(10-11), 853 - 9
Development of instrumentation to allow the detection of microorganisms using light scattering in combination with surface plasmon resonance; Perkins EA et al.; This paper describes work carried out to develop a biosensor which allows two separate detection principles to operate simultaneously at the same surface . A prototype device was constructed that provided Kretschmann-configuration surface plasmon resonance (SPR) measurement of refractive index (RI) changes using an 820 nm LED light source, whilst a 635 nm diode laser was used to produce light scattering signals from bacterial spores . Both effects occurred at a gold-coated surface . The RI changes were measured conventionally from the side of the gold layer nearer to the light sources . The scattered light was imaged from the opposite face which was in contact with the aqueous sample . Specific detection of bacterial spores through the light scattering mode using antibody capture was investigated . The flow dynamics and interactions with the surface of individual spores were observed . A comparison with SPR for detection using the same antibody/antigen pair was made . Spore suspensions that were readily detectable by light scattering at 10(7) ml(-1) did not provide significant responses by SPR . The potential for future developments is discussed.

Biosci Biotechnol Biochem, 2000 Jul, 64(7), 1321 - 7
Difructose anhydrides: their mass-production and physiological functions; Saito K et al.; Difructose anhydrides (DFAs) are the smallest cyclic disaccharides consisting of two fructose residues, and are expected to have novel physiological functions from their unique structures and properties . For mass-production of alpha-D-fructofuranose-beta-D-fructofuranose-2',1:2,3'-dianhydride (DFA III) and beta-D-fructofuranose-beta-D-fructofuranose-2',6:2,6'-dianhydride (DFA IV), Arthrobacter sp . H65-7 and A . nicotinovorans GS-9 were selected as the best producers of inulase II, which produced DFA III from inulin and LFTase, which produced DFA IV from levan . The enzymes were purified and their genes were subsequently cloned and expressed in E . coli at higher levels than in the original bacteria . Thus, it became possible to provide a large amount of DFA III and DFA IV for evaluating their physiological properties . DFA III and DFA IV have half the sweetness of sucrose, but cannot be digested by the digestive system of rats . Their use by the intestinal microorganisms was observed in vivo even though their assimilation could not be detected in vitro . This implied that they were degraded by an unknown system in the intestine . It was also found that they affected calcium absorption mainly in the small intestine through mechanisms different from the known stimulants such as fructooligosaccharides and raffinose.

Springer Semin Immunopathol, 2000, 22(1-2), 77 - 84
Multiple effects of immunostimulatory DNA on T cells and the role of type I interferons; Sun S et al.; In addition to stimulating antigen-specific immune responses, infectious agents cause nonspecific activation of the innate immune system, notably up-regulation of costimulatory/adhesion molecules on APCs and cytokine production . In recent years it has become apparent that stimulation of the immune system by microorganisms is a property of a number of different cellular components, including DNA . As discussed earlier and elsewhere in this volume, the DNA of infectious agents--and indeed of all non-vertebrates tested--differs from mammalian DNA in being enriched for unmethylated CpG motifs . With appropriate flanking sequences, CpG DNA and synthetic CpG ODNs cause strong activation of APCs and other cells . In this article we have focussed on the capacity of CpG DNA/ODNs to alter T cell function . Whether these compounds act directly on T cells or function indirectly by activating other cells, especially APCs, is controversial {7, 8, 13, 14} . In contrast to other workers {8}, we have yet to find definitive evidence that CpG DNA/ODNs can provide a co-stimulatory signal for purified T cells subjected to TCR ligation ({14} and unpublished data of authors) . For this reason we lean to the notion that CpG DNA/ODNs modulate T cell function by inducing activation of APC rather than by acting directly on T cells . When injected in vivo in the absence of specific antigen, CpG DNA/ODNs have two striking effects on T cells, namely (1) induction of overt activation (proliferation) of memory-phenotype CD8+ cells, and (2) partial activation of all T cells, including naive-phenotype T cells . Both actions of CpG DNA/ODNs are heavily dependent on the production of IFN-I by APC . For memory-phenotype (CD44hi) CD8+ cells, neither CpG DNA nor IFN-I can cause proliferation of purified APC-depleted T cells in vitro . Hence, under in vivo conditions, CpG DNA-induced proliferation of CD44hi CD8+ cells is probably mediated through the production of a secondary cytokine, i.e., by a cytokine that is directly stimulatory for CD44hi CD8+ cells . Based on the available evidence, it is highly likely that the effector cytokine is IL-15 . With this assumption, our current model is that proliferation of CD44hi CD8+ cells induced by injection of CpG DNA/ODNs reflects production of IFN-I which, in turn, leads to synthesis of IL-15 . Which particular cell types produce these two cytokines is unclear, although APCs are probably of prime importance . In addition to inducing proliferation of memory-phenotype CD8+ cells via IL-15, the IFN-I induced by CpG DNA/ODNs can also induce partial activation of naive T cells . This form of activation leads to up-regulation of CD69 and other molecules but does not cause entry into cell cycle . It is of interest that the partial activation of naive T cells induced by IFN-I is associated with decreased T proliferative responses . Thus, proliferation of purified naive T cells elicited by combined TCR/CD28 ligation in vitro is greatly reduced by addition of IFN-I . This inhibitory effect of IFN-I does not influence cytokine production and probably reflects production of cell cycle inhibitors . Surprisingly, except at high doses, IFN-I fails to exert an anti-proliferative effect when T proliferative responses are driven by viable APCs . Indeed, in this situation, IFN-I enhances antigen-specific T proliferative responses, both in vivo and in vitro . This adjuvant effect of IFN-I is presumably a reflection of APC activation, but direct evidence on this issue is still lacking . In this article we have emphasized that contact with CpG DNA/ODNs has multiple effects on T cell function in vivo . Many of these effects seem to be related to the production of certain cytokines by APCs, notably IFN-I and IL-15 . It should be stressed, however, that CpG DNA/ODNs probably lead to the production of many other cytokines . Hence, our current models of how CpG DNA/ODNs influence T cell function are undoubtedly oversimplified.

Biochem Biophys Res Commun, 2000 Aug 18, 275(1), 241 - 6
Surface expression of lactoferrin by resting neutrophils; Deriy LV et al.; We examined the surface expression of lactoferrin by human neutrophils . Western blot analysis with anti-lactoferrin antibodies demonstrated the presence of a 78- to 79-kDa band in plasma membranes isolated from resting neutrophils that corresponded to the 78- to 79-kDa protein in neutrophil secondary granules . Flow cytometry using FITC-conjugated anti-lactoferrin antibodies confirmed that lactoferrin is expressed on the neutrophil surface . Preincubating the neutrophils in acidic (pH 3.9) buffer did not alter staining of the cells by the antibodies . Surface expression of lactoferrin was also detected on neutrophils in whole blood . Neutrophil activation by C5a or the calcium ionophore A23187 did not increase the surface expression of lactoferrin . Instead, the level of lactoferrin expression detected with one of two monoclonal antibodies was diminished after neutrophil activation, suggesting a possible conformational change in the lactoferrin . The surface-expressed lactoferrin may provide a mechanism for the interaction between lactoferrin-binding microorganisms and neutrophils .

J Mol Microbiol Biotechnol, 1999 Nov, 1(2), 243 - 55
Cold shock response in mammalian cells; Fujita J; Compared to bacteria and plants, the cold shock response has attracted little attention in mammals except in some areas such as adaptive thermogenesis, cold tolerance, storage of cells and organs, and recently, treatment of brain damage and protein production . At the cellular level, some responses of mammalian cells are similar to microorganisms; cold stress changes the lipid composition of cellular membranes, and suppresses the rate of protein synthesis and cell proliferation . Although previous studies have mostly dealt with temperatures below 20 degrees C, mild hypothermia (32 degrees C) can change the cell's response to subsequent stresses as exemplified by APG-1, a member of the HSP110 family . Furthermore, 32 degrees C induces expression of CIRP (cold-inducible RNA-binding protein), the first cold shock protein identified in mammalian cells, without recovery at 37 degrees C . Remniscent of HSP, CIRP is also expressed at 37 degrees C and developmentary regulated, possibly working as an RNA chaperone . Mammalian cells are metabolically active at 32 degrees C, and cells may survive and respond to stresses with different strategies from those at 37 degrees C . Cellular and molecular biology of mammalian cells at 32 degrees C is a new area expected to have considerable implications for medical sciences and possibly biotechnology.

J Mol Microbiol Biotechnol, 1999 Nov, 1(2), 211 - 9
Cold shock response and low temperature adaptation in psychrotrophic bacteria; Hebraud M et al.; Psychrotrophic bacteria are capable of developing over a wide temperature range and they can grow at temperatures close to or below freezing . This ability requires specific adaptative strategies in order to maintain membrane fluidity, the continuance of their metabolic activities, and protein synthesis at low temperature . A cold-shock response has been described in several psychrotrophic bacteria, which is somewhat different from that in mesophilic microorganisms: (i) the synthesis of housekeeping proteins is not repressed following temperature downshift and they are similarly expressed at optimal and low temperatures (ii) cold-shock proteins or Csps are synthesized, the number of which increases with the severity of the shock (iii) a second group of cold-induced proteins, i.e . the cold acclimation proteins or Caps, comparable with Csps are continuously synthesized during prolonged growth at low temperature . Homologues to CspA, the major cold-shock protein in E . coli, have been described in various psychrotrophs, but unlike their mesophilic counterparts, they belong to the group of Caps . Although they have been poorly studied, Caps are of particular importance since they differentiate psychrotrophs from mesophiles, and they are probably one of the key determinant that allow life at very low temperature.

Cytometry, 2000 Sep 1, 41(1), 41 - 5
Individual Escherichia coli cells studied from light scattering with the scanning flow cytometer; Shvalov AN et al.; BACKGROUND: Flow cytometry is a powerful tool for the analysis of individual particles in a flow . Differential light scattering (an indicatrix) was used for many years to obtain morphologic information about microorganisms . The indicatrices play the same role for individual particle recognition as a spectrum for substance characterization . We combined two techniques to analyze the indicatrix of the cells for the purpose of developing a database of light-scattering functions of cells . METHODS: The scanning flow cytometer (SFC) allows the measurement of the entire indicatrix of individual particles at polar angles ranging from 5 degrees to 100 degrees . In this work, light-scattering properties of Escherichia coli have been studied both experimentally and theoretically with the SFC and the T-matrix method, respectively . The T-matrix method was used because of the nonspherical shape of E . coli cells, which were modeled by a prolate spheroid . RESULTS: The indicatrices of E . coli cells were stimulated with T-matrix method at polar angles ranging from 10 degrees to 60 degrees . The absolute cross-section of light scattering of E . coli has been determined comparing the cross section of polystyrene particles modeled by a homogeneous sphere . The E . coli indicatrices were compared for logarithmic and stationary phases of cell growth . CONCLUSIONS: The indicatrices of E . coli were reproducible and could be used for identification of these cells in biologic suspensions . The angular location of the indicatrix minimum can be used in separation of cells in logarithmic and stationary phases . To use effectively the indicatrices for that purpose, the light-scattering properties of other microorganisms have to be studied .

Am J Obstet Gynecol, 2000 Aug, 183(2), 431 - 7
Relationship of bacterial vaginosis and mycoplasmas to the risk of spontaneous abortion; Donders GG et al.; OBJECTIVE: This study was undertaken to investigate a possible link between first-trimester diagnosis of bacterial vaginosis and cessation of pregnancy at < or =20 weeks' gestation . STUDY DESIGN: Women (n = 228) who received routine prenatal care in Flanders, Belgium, during the first trimester (14 weeks' gestation) and had a living singleton fetus were examined for microbiologic flora of the vagina . Bacterial vaginosis was assessed either clinically (Amsel et al criteria), microscopically (clue cells), or by culture of bacterial vaginosis-associated bacteria . Data were analyzed univariately (relative risk) and multivariately . RESULTS: The presence of bacterial vaginosis at the first prenatal visit was strongly associated with subsequent early pregnancy loss (relative risk, 5.4; 95% confidence interval, 2.5-11) . After multivariate analysis bacterial vaginosis, Mycoplasma hominis, and Ureaplasma urealyticum but not other microorganisms remained associated with an increased risk of miscarriage . CONCLUSION: Bacterial vaginosis and mycoplasmas may play causative roles in spontaneous abortion and early pregnancy loss.

J Chromatogr B Biomed Sci Appl, 2000 Jun 23, 743(1-2), 247 - 54
Study on heterogeneity of beta-glucosidase from Aspergillus species by using counter-current distribution; Brumbauer A et al.; beta-Glucosidase plays a key role in cellulose degradation by cleaving its cellobiose units to glucose . The heterogeneity of the enzyme has been studied earlier by isoelectric focusing and several isoforms were found in the culture filtrate of Trichoderma and Aspergillus species . An aqueous two-phase system is an alternative fractionation method in which proteins are separated according to their net charge and surface properties . A dextran 500-poly(ethylene glycol) 8000 system was used to study the distribution of beta-glucosidase of different origins . To investigate the heterogeneity of enzymes 56- and 145-step thin-layer counter-current distributions were carried out . beta-Glucosidase produced by Aspergillus niger and Aspergillus carbonarius has been shown to consist of at least three isoenzymes by applying this method . The three forms of A . niger show the corresponding partition ratios with G values of 0.13, 0.22 and 0.31; and A . carbonarius 0.14, 0.22 and 0.36, respectively . However, the relative amount of these isoforms differs strongly between the two microorganisms.

J Clin Immunol, 2000 May, 20(3), 161 - 6
Molecular events of bacterial-induced maturation of dendritic cells; Rescigno M et al.; In order to protect the body from infectious microorganisms, mammals have developed powerful lines of defense, consisting in innate and adaptive immune responses . The innate response is phylogenetically more ancient and, for a long time, it has been considered to be broadly directed to microorganisms . However, the discovery of a new class of receptors, involved in recognition of patterns characteristic of groups of microorganisms (the toll-like receptor family) has re-evaluated the role of the innate immune system as a discriminating system . Indeed, there is increasing evidence that the induction of different types of effector adaptive responses are directed by the innate immune system after recognition of particular groups of pathogens . The central role of Dendritic cells (DC) in the induction of adaptive immune responses towards infectious agents has been extensively described, but, recently, a new role of DC as a link between the non-antigen- and the antigen-specific responses has been proposed . DC have, indeed, the capacity to recruit and activate cells of the innate immune system upon inflammation . Thus . understanding the interaction of bacteria with DC, and the early molecular events resulting from this interaction may shed some light on the mechanisms of initiation of the immune response to infectious agents and on aspects of invasiveness, pathogenicity, and the persistence of certain bacteria.

J Mol Microbiol Biotechnol, 1999 Aug, 1(1), 33 - 43
Microbial symbionts of marine invertebrates: opportunities for microbial biotechnology; Haygood MG et al.; Marine invertebrates are sources of a diverse array of bioactive metabolites with great potential for development as drugs and research tools . In many cases, microorganisms are known or suspected to be the biosynthetic source of marine invertebrate natural products . The application of molecular microbiology to the study of these relationships will contribute to basic biological knowledge and facilitate biotechnological development of these valuable resources . The bryostatin-producing bryozoan B . neritina and its specific symbiont "Candidatus Endobugula sertula" constitute one promising model system . Another fertile subject for investigation is the listhistid sponges that contain numerous bioactive metabolites, some of which originate from bacterial symbionts.

Plant Sci, 2000 Aug 8, 157(1), 43 - 50
Expression of threonine synthase from Solanum tuberosum L . is not metabolically regulated by photosynthesis-related signals or by nitrogenous compounds; Casazza AP et al.; Although the control of carbon fixation and nitrogen assimilation has been studied in detail, little is known about the regulation of carbon and nitrogen flow into amino acids . In this paper the isolation of a cDNA encoding threonine synthase is reported (TS; EC 4.2.99.2) from a leaf lambda ZAP II-library of Solanum tuberosum L . and the transcriptional regulation of the respective gene expression in response to metabolic changes . The pattern of expression of TS by feeding experiments of detached petioles revealed that TS expression is regulated neither by photosynthesis-related metabolites nor by nitrogenous compounds . The present study suggests that the regulation of the conversion of aspartate to threonine is not controlled at the transcript level of TS . The nucleotide and deduced amino acid sequences of potato TS show homology to other known sequences from Arabidopsis thaliana and microorganisms . TS is present as a low copy gene in the genome of potato as demonstrated in Southern blot analysis . When cloned into a bacterial expression vector, the cDNA did functionally complement the Escherichia coli mutant strain Gif41 . TS transcript was found in all tissues of potato and was most abundant in flowers and source leaves.

Int J Food Microbiol, 2000 Jul 15, 58(3), 159 - 72
Microbial risk assessment: dose-response relations and risk characterization; Buchanan RL et al.; Characterizations of the risks associated with foodborne pathogens are dependent on the availability of information on the population's exposure to the biological agents . However, by itself, exposure data are insufficient to assess the public health impact of pathogenic microorganisms . This requires the availability of effective dose-response models . Successful development of models that describe dose-response relations for enteric pathogens is dependent on a sound understanding of the mechanisms of pathogenicity associated with individual pathogens . This includes knowledge of how the various pathogen, host, and food matrix factors influence pathogenicity . Currently, a group of sigmoidal mathematical equations are used to empirically describe dose-response relations . While these have proven to be highly useful, advances in microbial food safety risk assessment will likely require the development of mechanistic models that more effectively consider the range of factors that influence the frequency and severity of foodborne infections in a population.

Metab Eng, 1999 Jul, 1(3), 232 - 42
Use and limitations of modular metabolic control analysis in medicine and biotechnology; Schuster S; By Metabolic Control Analysis (MCA), it has been shown that control on flux is in most cases shared by several enzymes rather than concentrated on one "rate-limiting step." This analysis also allows the quantification of the control exerted by groups (modules) of enzymes . The modules may correspond to spatial compartments or to functional units . A brief outline of the modular approach to MCA is given . The criteria by which the system can be modularized and the concept of monofunctional unit are explained . Various studies in which control analysis was applied to biotechnological and medical issues are reviewed . In particular, MCA has turned out to be helpful in the assessment of the severity of enzyme deficiencies . Another application is the search for target enzymes or enzyme groups where pharmaceuticals can suppress the metabolism of pathogenic microorganisms most . In biotechnology, modular and "traditional" control analyses are valuable tools for choosing the most promising targets for genetic manipulation so as to increase a biosynthetic flux . As control coefficients are linear approximations, the effect of enhancing the activities of enzymes to a larger extent is often overestimated . Further limitations such as the restriction to stationary states, uncertainties due to spatial heterogeneities and the impact of experimental error are discussed.

Am J Med, 2000 Jul, 109(1), 33 - 44
Phagocytes and oxidative stress; Babior BM; Neutrophils and other phagocytes manufacture O(2)(-) (superoxide) by the one-electron reduction of oxygen at the expense of NADPH . Most of the O(2)(-) reacts with itself to form H(2)O(2) (hydrogen peroxide) . From these agents a large number of highly reactive microbicidal oxidants are formed, including HOCl (hypochlorous acid), which is produced by the myeloperoxidase-catalyzed oxidation of Cl(-) by H(2)O(2); OH(*) (hydroxyl radical), produced by the reduction of H(2)O(2) by Fe(++) or Cu(+); ONOO(-) (peroxynitrite), formed by the reaction between O(2)(-) and NO(*); and many others . These reactive oxidants are manufactured for the purpose of killing invading microorganisms, but they also inflict damage on nearby tissues, and are thought to be of pathogenic significance in a large number of diseases . Included among these are emphysema, acute respiratory distress syndrome, atherosclerosis, reperfusion injury, malignancy and rheumatoid arthritis.

J Med Virol, 2000 Sep, 62(1), 46 - 51
Low induction of varicella-zoster virus-specific secretory IgA antibody after vaccination; Terada K et al.; Breakthrough after varicella vaccination occurs in approximately 2 . 6% approximately 18.6% of immunocompetent children, but the reason has not been demonstrated clearly . As a first defense, specific secretory IgA antibody on the mucosa plays an important role in preventing invasion of microorganisms . To examine induction of varicella-zoster virus (VZV) specific secretory IgA after natural infection and vaccination and its booster mechanisms, 143 salivary samples were tested by ELISA . The VZV-secretory IgA values were significantly higher in the matched children after natural chickenpox than in those after vaccination, although the total secretory IgA did not differ between them . Two (7%) of the vaccinees lacked the sIgA antibody . In the elderly and in immunocompromised children, the VZV-secretory IgA values were no lower than those in healthy children, and they did not lack VZV-secretory IgA . The doctors and nurses taking care of patients with chickenpox had higher values than the other groups as did individuals who had had herpes zoster recently . VZV-secretory IgA was thought to be stimulated by exogenous and reactivated endogenous VZV to neutralize VZV with weak activity . These results suggest that low or no induction of VZV-secretory IgA antibody after vaccination may be one of the possible explanations for a breakthrough .

Metab Eng, 2000 Jan, 2(1), 14 - 33
Metabolic modeling of Saccharomyces cerevisiae using the optimal control of homeostasis: a cybernetic model definition; Giuseppin ML et al.; A model is presented to describe the observed behavior of microorganisms that aim at metabolic homeostasis while growing and adapting to their environment in an optimal way . The cellular metabolism is seen as a network with a multiple controller system with both feedback and feedforward control, i.e., a model based on a dynamic optimal metabolic control . The dynamic network consists of aggregated pathways, each having a control setpoint for the metabolic states at a given growth rate . This set of strategies of the cell forms a true cybernetic model with a minimal number of assumptions . The cellular strategies and constraints were derived from metabolic flux analysis using an identified, biochemically relevant, stoichiometry matrix derived from experimental data on the cellular composition of continuous cultures of Saccharomyces cerevisiae . Based on these data a cybernetic model was developed to study its dynamic behavior . The growth rate of the cell is determined by the structural compounds and fluxes of compounds related to central metabolism . In contrast to many other cybernetic models, the minimal model does not consist of any assumed internal kinetic parameters or interactions . This necessitates the use of a stepwise integration with an optimization of the fluxes at every time interval . Some examples of the behavior of this model are given with respect to steady states and pulse responses . This model is very suitable for describing semiquantitatively dynamics of global cellular metabolism and may form a useful framework for including structured and more detailed kinetic models.

J Dermatol, 2000 Jul, 27(7), 450 - 2
Salivary gland MALT lymphoma associated with Helicobacter pylori infection in a patient with Sjögren's Syndrome; Nishimura M et al.; We report a case of salivary gland MALT lymphoma in Sjogren's syndrome associated with localized H . pylori infection . A 76-year-old woman had a history of bilateral cheek masses for two years . Histologically, the parotid glands were invaded by numerous centrocyte-like cells to form lymphoepithelial lesions . The tumor cells showed immunohistological differentiation into B cells . Southern blotting demonstrated immunoglobulin gene rearrangement . These results indicated that the tumors were MALT lymphoma . H . pylori, as assessed by the urease test (CLO test; BML Ltd., Tokyo, Japan), was positive in the tumor specimen . After wide local excision of the tumors followed by radio therapy and oral administration of antibiotics and proton pump inhibitor, no evidence of recurrence was found during the 24-months of follow up . H . pylori infection in the salivary gland is rare, although the source of infection and transmission of H . pylori organisms has been thought to be the oral cavity . We discussed the association between H . pylori infection and salivary gland MALT lymphoma . The microorganism may play a role as an additional antigenic stimulus for the development of salivary gland MALT lymphoma as well as for the development of gastric MALT lymphoma . This means that H . pylori can play a role in lymphoma progression as booster of B cell lymphoproliferation.

Mol Biotechnol, 1999 Nov, 13(1), 57 - 66
Methods for long-term virus preservation; Gould EA; Viruses exhibit a wide variety of structural and chemical differences, but, in general, their infectivity may be destroyed by degradative enzymes that destroy nucleic acids, by detergents that solubilize the lipid-containing envelopes thus exposing the nucleic acid, by temperatures higher than about 50 degrees C, or by chemicals that breakdown capsid proteins . Preserving the viruses at low or ultra-low temperatures, and/or in the absence of water, slows down these destructive processes sufficiently to increase significantly the length of time that the virus can be stored as infectious material . Supplements such as serum are presumed to stabilize the environmental conditions and to block degradative processes . The methods by which viruses may be preserved for long periods of time are similar to those employed for other microorganisms and are relatively simple . Nevertheless, attention to detail, good laboratory practice, aseptic technique, meticulous recordkeeping, and regular monitoring of the stored materials will increase the success rate and reduce problems of contamination or loss in the storage containers, where many different viruses may be stored for posterity! This article describes some of the simplest and most reliable storage procedures for viruses, but the author recognizes that everyone will have a favorite method to suit his or her own particular virus.

Rev Latinoam Microbiol, 1999 Jan-Mar, 41(1), 1 - 3
Serological survey of canine borreliosis; Salinas-Melendez JA et al.; Lyme disease or Borreliosis, a tick-borne disease caused by Borrelia burgdorferi, has been described recently in dogs . A total of 850 blood samples were obtained from dogs in the metropolitan area of Monterrey, Mexico . An indirect immunofluorescent assay (IFA) was used to detect antibodies against Borrelia burgdorferi, the etiologic agent of Lyme disease in human beings . The 16% (136) of these dogs had positive results . These findings suggest that exposition to this microorganism is common in dogs in this area and that this disease is of importance to veterinarians.

Mikrobiol Z, 2000 May-Jun, 62(3), 56 - 65
{The intensification of biological nitrogen fixation by using ammonium carbonate compounds and the routes of their action on microorganisms and plants}; Mal'tseva NN et al.; The intensification of activity of associative and symbiotic nitrogen fixation while using low amounts of ammonium-carbonate compounds, carbonic-ammonium salts, in particular, has been established . The main ways and mechanisms of the action of ammonium-carbonate salts as a new and perspective agrochemical on physiological and biochemical processes of microorganisms and agricultural plants were presented on the basis of the analysis of literary information and the author's investigations.

Mikrobiol Z, 2000 May-Jun, 62(3), 43 - 8
{The antibiotic sensitivity of microorganisms isolated from newborn infants}; Avdieieva LV; Bacterial strains (219) isolated from newborn children were studied for their sensitivity to 17 antibiotics . In the case of the species studied the increase of resistance to cephalothin, cefazolin, cefotaxime, ceftriaxone, gentamicin, tobramycin, chloramphenicol by 5.7 to 43% was found . This evidenced for a necessity to revise the tactics of their further use for treatment and prophylaxis, while the identification of the strains resistant to ofloxacin and ciprofloxacin evidenced for the appearance of new resistance determinants . The high level of resistance to antibiotics and practically identical profile of antibiotics in the strains isolated from newborns and epidemiologically significant environmental objects in the examined hospitals do point to possible colonization of newborns by the hospital strains.

Mikrobiol Z, 2000 May-Jun, 62(3), 36 - 42
{The effect of biostimulants and fungicides on the growth parameters of natural associations of soil microorganisms}; Iutyns'ka HO et al.; Biostimulants ivin and emistym take positive effect on the growth characteristics of natural association of soil microorganisms: they increase the specific growth rate, the number of generations, decrease the lag-phase and duration of redoubling the number of microorganisms . Presence of fungicides in the medium inhibits the growth of microorganisms . Under combined use of biostimulants and fungicides one cannot reveal the negative effect of fungicides on the natural associations of microorganisms, however the stimulating action of growth-regulating substances decreases.

Can J Microbiol, 2000 Jul, 46(7), 633 - 42
Purification and characterization of a common soil component which inhibits the polymerase chain reaction; Watson RJ et al.; DNA prepared from soil usually contains a brown-tinted inhibitor of the polymerase chain reaction (PCR) which limits the sensitivity of this technique for specific detection of microorganisms . To localize the inhibitor, soil fractions were tested for their inhibitory effect on the PCR reaction . A highly inhibitory activity, sufficient to account for the inhibition typically exhibited by soil DNA, was found to be tightly associated with the soil microorganism fraction . After cell breakage, the inhibitory material became soluble, and was not separable from DNA by standard purification procedures . A method was derived by which most of the inhibitory material could be selectively solubilized from the microorganism fraction without cell breakage, using successive washes with buffers differing in EDTA concentration . This technique was used to isolate a substance with characteristics suggesting that it is the major PCR inhibitor contaminating DNA purified from soil . It was found to be an organic, water-soluble compound of high molecular weight, and was present in a variety of soil types from different locations . It was found to be distinctly different in its solubility properties from humic and fulvic acids, and also in its FT-IR and NMR spectra . It forms a complex with protein and may inhibit the PCR reaction by an interaction with Taq DNA polymerase.

Clin Exp Immunol, 2000 Aug, 121(2), 295 - 301
The 75-kD tumour necrosis factor (TNF) receptor is specifically up-regulated in monocytes during Q fever endocarditis; Ghigo E et al.; Q fever is an infectious disease caused by Coxiella burnetii, an obligate intracellular microorganism that inhabits monocytes/macrophages . The dysregulated production of TNF-alpha in Q fever endocarditis has been associated with defective killing of C . burnetii by patient monocytes . As soluble receptors for TNF-alpha (TNF-R55 and TNF-R75) regulate TNF-alpha activity, we investigated their release by monocytes in Q fever . Spontaneous and C . burnetii-stimulated release of TNF-R75, but not of TNF-R55, was up-regulated in patients with ongoing endocarditis compared with controls . The increase in TNF-R75 release was related to the activity of Q fever endocarditis, since TNF-R75 release was similar in patients with cured endocarditis and controls . While spontaneous release of TNF-R75 by monocytes from patients with ongoing Q fever endocarditis occurred without changes in its membrane expression, C . burnetii increased the surface expression of TNF-R75 . In addition, TNF-R75 transcripts were increased in resting and C . burnetii-stimulated monocytes from patients with ongoing endocarditis . On the other hand, TNF-R75 release was not related to TNF-alpha secretion . These results indicate that the modulation of TNF-R75 is a critical feature of the pathophysiology of Q fever endocarditis.

FEMS Microbiol Lett, 2000 Aug 15, 189(2), 219 - 23
Antibiotic production in relation to bacterial growth and nematode development in Photorhabdus--Heterorhabditis infected Galleria mellonella larvae; Hu K et al.; The population of Photorhabdus luminescens C9, bacterial symbiont of the entomopathogenic nematode, Heterorhabditis megidis 90, increased rapidly to 1.2-2.6x10(9) cells g(-1) wet Galleria mellonella larvae within 24 h of nematode infection of the larvae, and maintained a relatively constant level (1.2-2.0x10(10) cells g(-1)) through the entire 14-day period of nematode development . The antibiotic, 3, 5-dihydroxy-4-isopropylstilbene, was produced by P . luminescens C9 after 24 h of nematode infection, increased rapidly at 2-5 days postinfection and remained at a level of 3000-3600 microg g(-1) wet larvae until about 21 days, decreasing gradually thereafter . The early production and continued presence of a relatively large amount of 3,5-dihydroxy-4-isopropylstilbene in the infected insect supports the hypothesis that the antibiotics produced by the bacterial symbiont help minimize competition from other microorganisms and prevents the putrefaction of the nematode-infected insect cadaver.

Free Radic Biol Med, 2000 May 15, 28(10), 1451 - 5
Interaction of peroxynitrite with selenoproteins and glutathione peroxidase mimics; Sies H et al.; Peroxynitrite is an oxidant generated under inflammatory conditions, acting in defense against invading microorganisms . There is a need for protection of the organism from damage inflicted by peroxynitrite . Selenium-containing compounds, notably ebselen, have a high second-order reaction rate constant (approx . 2 x 10(6) M(-1) s(-1)), which makes them candidates for efficient protection . This applies also for selenium in proteins, occurring as selenocysteine or selenomethionine residues . Glutathione peroxidases, thioredoxin reductase, and selenoprotein P have been shown to play a potential role in protection against peroxynitrite . Tellurium-containing compounds also react with peroxynitrite.

Clin Chem, 2000 Aug, 46(8 Pt 1), 1157 - 61
An IgM lambda antibody to Escherichia coli produces false-positive results in multiple immunometric assays; Covinsky M et al.; BACKGROUND: Interferences in immunometric assays as a result of human anti-immunoglobulin antibodies frequently have been described in the literature . The etiology of these interfering antibodies is usually not known but has been associated with rheumatoid factors in some assays . It is known that microorganisms in experimental settings can induce anti-immunoglobulin antibodies . METHODS: Following Escherichia coli septicemia, a 56-year-old male patient had increased immunoassay results for cardiac troponin I, thyrotropin, human chorionic gonadotropin, alpha-fetoprotein, and CA-125 that were consistent with myocardial infarction, hyperthyroidism, and pregnancy, and suggestive of an occult neoplasm such as hepatic or ovarian cancer . None of these diagnoses were consistent with the rest of his medical exam . In addition, the patient had a restricted IgM lambda paraprotein by immunofixation . Plasma from the patient was incubated with Sepharose-conjugated protein A, irrelevant murine monoclonal antibodies, and formalin-killed E . coli organisms from his infection to determine whether these immunoassay values were falsely increased . RESULTS: Incubation of the patient's plasma with irrelevant murine monoclonal antibodies or the E . coli organism produced normal immunoassay values and removed the IgM lambda paraprotein . CONCLUSIONS: The patient produced a very restricted IgM lambda antibody response to the E . coli infection that had anti-immunoglobulin activity and caused falsely increased values in numerous immunometric assays . Microorganism-induced anti-immunoglobulin antibodies are discussed in the context of this patient.

J Nat Prod, 2000 Jul, 63(7), 969 - 74
Antineoplastic agents 440 . Asymmetric synthesis and evaluation of the combretastatin A-1 SAR probes (1S,2S)- and (1R,2R)-1, 2-dihydroxy- 1-(2',3'-dihydroxy-4'-methoxyphenyl)-2-(3' ',4' ',5' '-trimethoxyphenyl)-ethane; Pettit GR et al.; The synthetic (E)-isomer (3b) of natural combretastatin A-1 (1a) isolated from the African bushwillow Combretum caffrum was the focus of chiral hydroxylation (Sharpless) reactions as part of a structure-activity relationship study . The resulting (R,R)- and (S,S, )-diols (6 and 7) and synthetic intermediates were evaluated against a series of cancer cell lines, microorganisms, and tubulin . Chiral diols 6 and 7 showed increased activity against the P-388 murine lymphocytic leukemia cell line with ED(50) values of 3.9 and 2.9 microg/mL, respectively, when compared to the precursor (E)-stilbene 3b . In contrast, (E)-stilbene 3b exhibited more potent antibiotic activity than the chiral diols (6 and 7) . Both diols, (R,R)-6 and (S, S)-7, displayed less cancer cell growth inhibition and less antibiotic activity than did natural combretastatin A-1 (1a) (P-388 ED(50) 0.25 microg/mL).

Appl Environ Microbiol, 2000 Aug, 66(8), 3603 - 7
Unlabeled helper oligonucleotides increase the in situ accessibility to 16S rRNA of fluorescently labeled oligonucleotide probes; Fuchs BM et al.; Target site inaccessibility represents a significant problem for fluorescence in situ hybridization (FISH) of 16S rRNA with oligonucleotide probes . Here, unlabeled oligonucleotides (helpers) that bind adjacent to the probe target site were evaluated for their potential to increase weak probe hybridization signals in Escherichia coli DSM 30083(T) . The use of helpers enhanced the fluorescence signal of all six probes examined at least fourfold . In one case, the signal of probe Eco474 was increased 25-fold with the use of a single helper probe, H440-2 . In another case, four unlabeled helpers raised the FISH signal of a formerly weak probe, Eco585, to the level of the brightest monolabeled oligonucleotide probes available for E . coli . The temperature of dissociation and the mismatch discrimination of probes were not significantly influenced by the addition of helpers . Therefore, using helpers should not cause labeling of additional nontarget organisms at a defined stringency of hybridization . However, the helper action is based on sequence-specific binding, and there is thus a potential for narrowing the target group which must be considered when designing helpers . We conclude that helpers can open inaccessible rRNA regions for FISH with oligonucleotide probes and will thereby further improve the applicability of this technique for in situ identification of microorganisms.

Appl Environ Microbiol, 2000 Aug, 66(8), 3249 - 54
Use of self-assembled monolayers of different wettabilities to study surface selection and primary adhesion processes of green algal (Enteromorpha) zoospores; Callow ME et al.; We investigated surface selection and adhesion of motile zoospores of a green, macrofouling alga (Enteromorpha) to self-assembled monolayers (SAMs) having a range of wettabilities . The SAMs were formed from alkyl thiols terminated with methyl (CH(3)) or hydroxyl (OH) groups or mixtures of CH(3)- and OH-terminated alkyl thiols and were characterized by measuring the advancing contact angles and by X-ray photoelectron spectroscopy . There was a positive correlation between the number of spores that attached to the SAMs and increasing contact angle (hydrophobicity) . Moreover, the sizes of the spore groups (adjacent spores touching) were larger on the hydrophobic SAMs . Video microscopy of a patterned arrangement of SAMs showed that more zoospores were engaged in swimming and "searching" above the hydrophobic sectors than above the hydrophilic sectors, suggesting that the cells were able to "sense" that the hydrophobic surfaces were more favorable for settlement . The results are discussed in relation to the attachment of microorganisms to substrata having different wettabilities.

Int J STD AIDS, 2000 Jul, 11(7), 435 - 9
The association of Chlamydia trachomatis and Mycoplasma genitalium with non-gonococcal urethritis: observations on heterosexual men and their female partners; Keane FE et al.; Our objectives were to study the distribution of Chlamydia trachomatis and Mycoplasma genitalium in men with or without non-gonococcal urethritis (NGU) and their respective female partners . A case-control study was carried out to which men with or without NGU and their female partners were recruited . All study participants were tested for the presence of C . trachomatis and M . genitalium . An analysis firstly of the distribution of each of these microorganisms among men with or without urethritis and their respective female partners was carried out . Furthermore, we examined the association of each of these microorganisms and NGU when the other had been excluded . Chlamydia trachomatis was present in 14 (36%) of 39 men with NGU compared to none of 12 men without NGU (P=0.022) . The prevalence rates for female partners of men with NGU were 10 (26%) of 39 compared to none of 12 partners of men without NGU (P=0.092) . M . genitalium was detected in 12 (33%) of 36 men with NGU compared to 1 (9%) of men without NGU (not significant; P=0.147) . The prevalence rates for female partners of men with NGU were 10 (32%) of 31 women compared to none of 7 partners of men without NGU (not significant; P=0.156) . There was a greater concordance than discordance of carriage of each of the 2 microorganisms among the study couples and each tended to be carried independently of the other by men . Analysis of the association between the presence of C . trachomatis in men and NGU was significantly improved by the exclusion of men with M . genitalium (P=0.0058) . Likewise, the association between the presence of M . genitalium in men and NGU was significantly improved by the exclusion of couples in whom either the man or woman was C . trachomatis-positive (P=0.049) . The independent carriage of C . trachomatis and M . genitalium by men with NGU, coupled with the improved association between each pathogen and NGU by exclusion of the other provides support for the separate role of each in the aetiology of NGU.

Curr Microbiol, 2000 Jul, 41(1), 70 - 2
Specificity of a neutral Zn-dependent proteinase from Thermoactinomyces sacchari toward the oxidized insulin B chain; Georgieva DN et al.; The proteolytic specificity of the neutral Zn-dependent proteinase from Thermoactinomyces sacchari was determined by analysis of the peptides obtained after incubation with the oxidized insulin B chain as a substrate . The enzyme is an endopeptidase with broad specificity . In total, 12 peptide bonds in the B chain of insulin were hydrolyzed . The major requirement is that a hydrophobic residue such as Leu, Val, or Phe should participate with the alpha-amino group in the bond to be cleaved . However, hydrolysis of bonds at the N-terminal side of His, Thr, and Gly was also observed . The peptide bond Leu 15-Tyr 16 in the oxidized insulin B chain, which is the major cleavage site for the alkaline microbial proteinases, is resistant to the attacks of the enzyme from Thermoactinomyces sacchari and other neutral proteinases . The proteolytic activity of the Zn-dependent proteinase from T sacchari is different from those of other metalloendopeptidases from microorganisms.

Appl Microbiol Biotechnol, 2000 Jun, 53(6), 690 - 4
Rapid and specific identification of medium-chain-length polyhydroxyalkanoate synthase gene by polymerase chain reaction; Solaiman DK et al.; A polymerase chain reaction (PCR) protocol was developed for the specific detection of genes coding for type II polyhydroxyalkanoate (PHA) synthases . The primer-pair, I-179L and I-179R, was based on the highly conserved sequences found in the coding regions of Pseudomonas phaC1 and phaC2 genes . Purified genomic DNA or lysate of colony suspension can serve equally well as the target sample for the PCR, thus affording a simple and rapid screening of phaC1/C2-containing microorganisms . Positive samples yield a specific 540-bp PCR product representing partial coding sequences of the phaC1/C2 genes . Using the PCR method, P . corrugata 388 was identified for the first time as a medium-chain-length (mcl)-PHA producer . Electron microscopic study and PHA isolation confirmed the production of mcl-PHA in P . corrugata 388 . The mcl-PHA of this organism has a higher molecular weight than that of similar polymers produced by other pseudomonads.

Acta Vet Scand, 1999, 40(4), 307 - 14
Mortality in farmed mink: systematic collection versus arbitrary submissions for diagnostic investigation; Rattenborg E et al.; The distribution of diagnoses of mortality in mink submitted to the Danish Veterinary Laboratory (DVL) for diagnostic investigation in the calendar year 1997 was compared with the diagnoses of mortality in all dead mink collected at 4 selected farms (project farms) during the same period . A total of 1,015 submitted mink and 1,149 mink from the 4 project farms were subjected to post mortem investigation . The average size (breeding stock) of the project farms was larger than Danish farms on average . However, the distribution of colour types of the mink was comparable . The seasonal distribution of the material from project farms and that of the submissions were approximately the same . Differences in the distribution of diagnoses as well as recovered microorganisms were found, however, mainly related to the proportion of gastro-intestinal disorders and E . coli respectively . These proportions were negatively correlated . Overall the results showed that extrapolating diagnostic results of laboratory submissions to the population of farmed mink may be problematic, and more reliable methods for disease surveillance must be considered.

South Med J, 2000 Jul, 93(7), 692 - 7
Utility of bone marrow biopsy for rapid diagnosis of febrile illnesses in patients with human immunodeficiency virus infection; Luther JM et al.; BACKGROUND: Histochemical staining of bone marrow biopsy samples for microorganisms may provide a presumptive diagnosis weeks before culture . METHODS: To identify predictors of histochemical positivity, we reviewed 161 bone marrow biopsies from febrile patients with human immunodeficiency virus (HIV) infection . RESULTS: By multivariate analysis, both hematocrit value <30% and white blood cell count <4,000/mm3 predicted biopsy positivity by culture or staining, but only anemia predicted histochemical stain positivity . Of cases with serum lactate dehydrogenase (LDH) levels >600 U/L, histoplasmosis was diagnosed in 31.6% versus 7.8% with lower LDH levels . Among histoplasmosis cases, staining showed fungi in all, with LDH levels >600 U/L versus 44.4% with lower levels . CONCLUSIONS: Bone marrow biopsy will most likely provide a rapid diagnosis in patients with anemia . Markedly elevated LDH levels suggest stain positivity for Histoplasma capsulatum . Histopathologic patterns may also guide empiric therapy.

Support Care Cancer, 2000 Jul, 8(4), 287 - 92
New tools in diagnosing catheter-related infections; Blot F et al.; Clinical criteria alone are insufficient to allow a diagnosis of intravascular catheter-related sepsis (CRS) . A definite diagnosis of CRS usually requires removal of the catheter for quantitative catheter tip culture . However, only about 15-25% of central venous catheters (CVC) removed because infection is suspected actually prove to be infected, and the diagnosis is always retrospective . Other diagnostic tests, such as differential quantitative blood cultures from samples taken simultaneously from the catheter and a peripheral vein, have been proposed to avoid unjustified removal of the catheter and the potential risks associated with the placement of a new catheter at a new site: a central-to-peripheral blood culture colony count ratio of 5:1 to 10:1 is considered indicative of CRS . Despite its high specificity, the latter diagnostic technique is not routinely used in clinical practice because of its complexity and cost . The measurement of the differential time to positivity between hub blood (taken from the catheter port) and peripheral blood cultures might be a reliable tool facilitating the diagnosis of CRS in situ . In an in vitro study, we found a strong relationship between the inoculum size of various microorganisms and the time to positivity of cultures . When the times to positivity of cultures of blood taken simultaneously from central and peripheral veins in patients with and without CRS were examined, we found that earlier positivity of central vs peripheral vein blood cultures was highly correlated with CRS . Using a cut-off value of +120 min, the "differential time to positivity" of the paired blood samples, defined as time to positivity of the peripheral blood minus that of the hub blood culture, had 91% specificity and 94% sensitivity for the diagnosis of CRS . This method may be coupled with other techniques that have high negative predictive value, such as skin cultures at the catheter exit site . This diagnostic test can be proposed for routine clinical practice in most hospitals using automatic devices for blood cultures positivity detection . Endoluminal brushing of the catheter is considered sensitive and specific for the diagnosis of CRS, but the risk of embolisation or subsequent bacteraemia should be considered . Gram staining and the acridine-orange leucocyte cytospin test on through-catheter blood culture have been proposed for rapid diagnosis of CRS without catheter removal . The technique, which requires 100 microl catheter blood and the use of light and ultraviolet microscopy, is considered simple, rapid (30 min) and inexpensive . In conclusion, diagnostic tools such as paired blood cultures or Gram staining and the acridine-orange leucocyte cytospin test should allow a diagnosis of CRS without catheter removal in cancer patients.

Ned Tijdschr Geneeskd, 2000 Jul 15, 144(29), 1385 - 8
{Decreasing prevalence of Helicobacter pylori: a consequence of treatment of gastroduodenal ulcers}; van der Weerd NC et al.; Four patients with gastroduodenal ulcers in the absence of Helicobacter pylori illustrate the decreasing prevalence of this microorganism . One was a 19-year-old boy with nausea, diarrhoea and weight loss caused by multiple gastroduodenal ulcers due to the Zollinger-Ellison syndrome . Another was a 36-year-old man with abdominal discomfort caused by an ulcer due to Crohn's disease . The other two cases concerned a 29-year-old man and a 68-year-old woman with relapsing ulcer disease and active bleeding, in whom no causal factors could be determined . Recent studies suggest a decreasing prevalence of H . pylori leading to both a relative and an absolute decrease of gastroduodenal ulcers attributed to H . pylori . Future treatment strategies will have to take these altered prevalence rates into consideration.

Mikrobiologiia, 2000 May-Jun, 69(3), 433 - 40
{On the vertical distribution of microorganisms in lake Baikal during spring deep-water renewal}; Parfenova VV et al.; The vertical distribution of microorganisms during spring deep-water renewal in Lake Baikal was studied . The downward advection of trophogenic waters was found to create conditions for the extensive growth of microorganisms capable of decomposing and mineralizing organic carbon, nitrogen, and phosphorus in deep water layers . These processes occur annually at spring thermal bars near the underwater slope of Lake Baikal, whereas in its pelagic zone, the deep intrusions of waters rich in organic material are observed only in the years when enhanced deep-water renewal is accompanied by a high spring yield of phytoplankton.

Mikrobiologiia, 2000 May-Jun, 69(3), 420 - 5
{Effect of phosphorus on the colonization of barley rhizosphere by microorganisms}; Orazova MX et al.; The mineral phosphorus supply produced two outbreaks in the bacterial population of the barley rhizosphere and rhizoplane but inhibited the growth of fungal mycelium . The inhibition of mycelial growth might be due to the exudation of specific inhibitors by barley roots, since the most pronounced inhibition was observed at high doses of supplementary phosphorus.

Am J Obstet Gynecol, 2000 Jul, 183(1), 252 - 6
Individual immunity and susceptibility to female genital tract infection; Witkin SS et al.; The responses to genital tract infection vary among different women to a far greater extent than has previously been appreciated . All women are not genetically identical and have not been exposed to identical environments; therefore it is naive to expect that a particular microorganism will elicit the identical response and have the identical sequelae for each infected individual . The genes inherited from one's parents, which contain specific polymorphisms in immune response genes, greatly influence the direction and magnitude of the immune response to microorganisms . Similarly, extrinsic variables, such as the type or quantity of a specific infection, whether there is a coinfection with another microorganism, such as an intracellular parasite, and whether an immediate hypersensitivity response is concurrently induced also determine the nature of the host response and thus the consequences of microbial exposure . Finally, factors such as the frequency of sexual intercourse and previous immune sensitization to spermatozoa or other components of a particular ejaculate also influence the outcome . An increased awareness of the uniqueness of each host will lead to the development of more precise individualized treatments and improvements in combating infectious diseases of the female genital tractPublication Types:

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