Ecotoxicol Environ Saf, 2001 Mar, 48(3), 241 - 54 Complex dynamics of adaptation in a nonaxenic microcystis culture . 2 . Computer simulation of dinotrophenol effects; Montague CL et al.; A hypothesis was modeled to account for complex 20-day dynamics in a culture of blue-green algae Microcystis and heterotrophic bacteria exposed to 2,4-dinitrophenol (DNP) . In trials with little or no added DNP, a limiting factor (light or CO(2)) may cause algal density to fluctuate after 14 days of increase . Such factors may be unimportant at levels of DNP that restrict photosynthesis . Bacterial growth may be limited by organic substrate, and bacteria may be more resistant to DNP than blue-green algae . Hence, at intermediate levels of DNP, substrate provided by increased algal death stimulates bacterial growth more than DNP retards it, causing a bacterial peak . Sorption of DNP to cells may cause the DNP decline . Greater growth and slower DNP decline in experiments with preexposed organisms indicate lower DNP sorption affinity in preexposed cells . Bacterial assimilation of DNP-containing substrate may cause the reappearance of DNP . The model reproduced the fluctuation in algal density after growth was limited and better growth and lower DNP decline with preexposed organisms . Reappearance of DNP occurred, but was not obvious . Bacterial dynamics were least well reproduced . Changes in bacterial constants most affected output . Despite model inadequacies, probable aspects of toxicant action in nature have been revealed . Ecological relationships among populations of different species and genetic differences among individuals may have led to lower than expected toxicity, adaptation, and even growth stimulation . Responses of single species tested in isolation may be inadequate to predict toxicant impact . Ecotoxicol Environ Saf, 2001 Mar, 48(3), 235 - 40 Complex dynamics of adaptation in a nonaxenic microcystis culture . 1 . Effects of dinitrophenol on population growth; Genoni GP et al.; Chronic exposure to toxicants is a selective pressure affecting populations and also the interactions between populations . Nonaxenic cultures of the blue-green alga Microcystis aeruginosa were used to investigate the ecological dynamics and the effect of preexposure to 2,4-dinitrophenol (DNP) on the tolerance toward subsequent DNP inputs . It was predicted that preexposure would induce an increased tolerance to further inputs . This should cause a higher population growth rate under a given DNP exposure, a broader tolerance range (the range of concentrations over which population growth can be sustained), a higher EC(50), and a lesser variability in growth rates, over the range of experimental exposure concentrations . DNP reduced Microcystis growth proportionally to exposure concentration . Light, inorganic carbon, and DNP were likely limiting factors for algal growth . Heterotrophic bacteria presumably used the dead cells and the exudate of living algae as substrates . Some unexpected effects occurred, such as an apparent increase in dissolved DNP in the medium following its initial decline and fluctuations of the bacterial population . The hypotheses were verified as concerns the effect of preexposure on tolerance . Changes were apparent in the EC(50) and in the breadth of the tolerance range . Moreover, the variability of preexposed populations, in terms of algal growth rate, over the range of exposure concentrations, was smaller than that of non-preexposed populations . Such a decrease in variability may reduce the potential of a population to resist further stresses . Cryobiology, 2000 Dec, 41(4), 257 - 79 Ice nucleation and antinucleation in nature; Zachariassen KE et al.; Plants and ectothermic animals use a variety of substances and mechanisms to survive exposure to subfreezing temperatures . Proteinaceous ice nucleators trigger freezing at high subzero temperatures, either to provide cold protection from released heat of fusion or to establish a protective extracellular freezing in freeze-tolerant species . Freeze-avoiding species increase their supercooling potential by removing ice nucleators and accumulating polyols . Terrestrial invertebrates and polar marine fish stabilize their supercooled state by means of noncolligatively acting antifreeze proteins . Some organisms also depress their body fluid melting point to ambient temperature by evaporation and/or solute accumulation . Ann Otol Rhinol Laryngol, 2001 Feb, 110(2), 132 - 41 Immortalization of rat middle ear epithelial cells by adeno 12-SV40 hybrid virus; Ueyama S et al.; Rat middle ear epithelial cells were infected with the adeno 12-SV40 hybrid virus . The cell line thus obtained displays features of primary cultured epithelial cells in both light microscopic and ultrastructural examinations . The immortalized cells have been in continuous proliferation for 40 passages and more than 17 months . Immunohistochemical analysis of the immortalized cells was positive for the SV40 T antigen and the tumor suppressor protein p53 . The cells also stained positive for cytokeratin, an epithelial cell marker, and negative for vimentin, a fibroblast marker . These results, together with karyotype analysis, indicate that this cell line originated from rat middle ear epithelial cells and retains the characteristics of epithelial cells . This cell line will be useful for studying the normal cellular biology of middle ear epithelial cells, as well as the cellular and molecular mechanisms involved in the bacteria-middle ear epithelial cell interaction. Dent Update, 2000 Jul-Aug, 27(6), 272 - 6 Dentine caries: take it or leave it? Banerjee A, Watson TF, Kidd EA. In modern dentistry the primary aim when excavating carious dentine is to eradicate only the highly infected, irreversibly demineralized and denatured biomass in order to allow effective restoration of the cavity, restoration of the surface anatomy of the tooth and to prevent disease progression . However, the boundary between this superficial zone of dentine requiring excavation and the deeper, affected but repairable tissue is not always obvious either in the clinic or in the research laboratory . The inherent subjectivity in detecting this excavation boundary can result in clinically significant differences in the quality and quantity of dentine removed by different operators and makes the in vitro comparison of newer excavation techniques more difficult . This article discusses the rationale behind carious dentine excavation and the criteria available to the dentist, both clinical and laboratory, to help identify the dentine requiring removal. Nippon Rinsho, 2001 Feb, 59(2), 342 - 8 {Gastric mucosal immunity induced by H . pylori infection}; Yokota K et al.; H . pylori infection induces various humoral and cellular immunities in gastric mucosa . Some reports indicate predominant CD4+ cells infiltrate in H . pylori infected gastric mucosa, and these cells express the T helper 1 phenotype . Local humoral immunity is also induced . Gastric plasma cells produce anti-H . pylori antibodies, however, their protective immunity is not enough to eradicate bacteria in human . We found heat shock protein 60 kDa (hsp60) may be closely associated with pathogenesis in MALT lymphoma . IgG1 antibodies to hsp60 were significantly correlated with the antibodies to H . pylori whole cell in patients with MALT lymphoma . CD40-CD40L dependent B cell proliferation was induced by cytokine and/or hsp60 stimulations in those patients . Cytotoxicity of gastric epithelial cells which is associated with host immunity induced by H . pylori infection is still unclear . We found that lymphocytes from patients with peptic ulcer showed cytotoxicity to gastric cell line HGC-27 in vitro . Cytotoxicity was enhanced by cytokine stimulus to T-lymphocytes and by heat stress and/or patients' antibodies treatment of HGC-27 cells . The pathogenicity of H . pylori may involve not only bacterial virulence factor but also host immunity . Studies of mucosal local immunity will help explain the mechanisms of H . pylori induced gastrodoudenal diseases. Nippon Rinsho, 2001 Feb, 59(2), 273 - 9 {Rapid urease test}; Aoyama N et al.; The rapid urease test is a simple, sensitive, and highly specific test that enables the endoscopist to diagnose Helicobacter pylori infection in the endoscopy room . Determination of the infection status of Helicobacter pylori by biopsies from the gastric body had a significantly higher sensitivity than antral biopsies . A false-negative reaction by rapid urease test occurred the use of antibiotics (correlates with clearance of the bacteria) and the use of proton pump inhibitor or a part of mucosal protective agents(correlates urease inhibitory effect) and in the case of non-urease producing Helicobacter pylori . The rapid urease test satisfactory overall sensitivity before eradication treatment . However, the sensitivity of these rapid urease tests was lower after eradication than before eradication. Appl Occup Environ Hyg, 2001 Feb, 16(2), 159 - 63 MEGA-database: one million data since 1972; Stamm R; MEGA is the chemical workplace exposure database of the Institute for Occupational Safety (BIA) of the German Berufsgenossenschaften (BG) (statutory accident institutions for insurance and prevention) . On the legal basis of the social insurance law the inspectorates of the BGs conduct workplace measurements of chemical and biological agents . The BGs have cooperated with BIA within the Berufsgenossenschaftliches Messsystem Gefahrstoffe--BGMG since 1972: measurements are done by the BGs, analyses and data processing are the tasks of BIA . In 1999 31,000 measurements with 68,000 analyses were taken in 4,000 enterprises . All data are stored in the MEGA-database with up to 150 pieces of information (describing type of workplace, working conditions, measured substances, sampling strategy, sampling duration, sampling and analytical method etc.), for each result . MEGA contains today about 1,000,000 measurements of more than 400 substances starting in 1972 . MEGA is used by BIA and the BGs for the following purposes: prevention (e.g., identification of hazards, efficiency of exposure reducing measures, determination of technical criteria for exposure limit values), epidemiological questions, and investigations of occupational diseases . In the framework of the measuring and inspection activities and tasks of the inspectorates of the BGs the locations for measurements are not randomly selected, but are based on criteria such as supposed critical exposure situations or testing the efficiency of exposure reducing measures . Nevertheless, a statistical appraisal of the data is possible for different purposes considering the specific determinants of the results, as, for example, classification of enterprises (sectors), workplaces (activities, tasks), used materials, and products . The MEGA-database will be further developed into a multifactorial exposure database with additional data on biological exposure to bacteria and funghi, but also noise and other data. Adv Biochem Eng Biotechnol, 2001, 71, 1 - 49 Polyesters in higher plants; Kolattukudy PE; Polyesters occur in higher plants as the structural component of the cuticle that covers the aerial parts of plants . This insoluble polymer, called cutin, attached to the epidermal cell walls is composed of interesterified hydroxy and hydroxy epoxy fatty acids . The most common chief monomers are 10,16-dihydroxy C16 acid, 18-hydroxy-9,10 epoxy C18 acid, and 9,10,18-trihydroxy C18 acid . These monomers are produced in the epidermal cells by omega hydroxylation, in-chain hydroxylation, epoxidation catalyzed by P450-type mixed function oxidase, and epoxide hydration . The monomer acyl groups are transferred to hydroxyl groups in the growing polymer at the extracellular location . The other type of polyester found in the plants is suberin, a polymeric material deposited in the cell walls of a layer or two of cells when a plant needs to erect a barrier as a result of physical or biological stress from the environment, or during development . Suberin is composed of aromatic domains derived from cinnamic acid, and aliphatic polyester domains derived from C16 and C18 cellular fatty acids and their elongation products . The polyesters can be hydrolyzed by pancreatic lipase and cutinase, a polyesterase produced by bacteria and fungi . Catalysis by cutinase involves the active serine catalytic triad . The major function of the polyester in plants is as a protective barrier against physical, chemical, and biological factors in the environment, including pathogens . Transcriptional regulation of cutinase gene in fungal pathogens is being elucidated at a molecular level . The polyesters present in agricultural waste may be used to produce high value polymers, and genetic engineering might be used to produce large quantities of such polymers in plants. J Environ Qual, 2001 Jan-Feb, 30(1), 24 - 30 Potential mineralization of four herbicides in a ground water--fed wetland area; Larsen L et al.; Herbicides may leach from agricultural fields into ground water feeding adjacent wetlands . However, only little is known of the fate of herbicides in wetland areas . The purpose of the study was to examine the potential of a riparian fen to mineralize herbides that could leach from an adjacent catchment area . Slurries were prepared from sediment and ground water collected from different parts of a wetland representing different redox conditions . The slurries were amended with O2, NO3-, SO4(2-), and CO2, or CO2 alone as electron acceptors to simulate the in situ conditions and their ability to mineralize the herbides mecoprop, metsulfuron-methyl, isoproturon and atrazine . In addition, the abundance of bacteria able to utilize O2, NO3-, SO4(2-) + CO2, and CO2 as electron acceptors was investigated along with the O2-reducing and methanogenic potential of the sediment . The recalcitrance to bacterial degradation depended on both the type of herbicide and the redox conditions pertaining . Mecoprop was the most readily degraded herbicide, with 36% of {ring-U-14C}mecoprop being mineralized to 14CO2 under aerobic conditions after 473 d . In comparison, approximately 29% of {phenyl-U-14C}metsulfuron-methyl and 16% of {ring-U-14C}isoproturon mineralized in aerobic slurries during the same period . Surprisingly, 8 to 13% of mecoprop also mineralized under anaerobic conditions . Neither metsulfuron-methyl nor isoproturon were mineralized under anaerobic conditions and atrazine was not mineralized under any of the redox conditions examined . The present study is the first to report mineralization of meco-prop in ground water in a wetland area, and the first to report mineralization of a phenoxyalcanoic acid herbicide under both aerobic and anaerobic conditions. Environ Microbiol, 2000 Dec, 2(6), 666 - 79 Effects of O2 and CH4 on presence and activity of the indigenous methanotrophic community in rice field soil; Henckel T et al.; The activity and distribution of methanotrophs in soil depend on the availability of CH4 and O2 . Therefore, we investigated the activity and structure of the methanotrophic community in rice field soil under four factorial combinations of high and low CH4 and O2 concentrations . The methanotrophic population structure was resolved by denaturant gradient gel electrophoresis (DGGE) with different PCR primer sets targeting the 16S rRNA gene, and two functional genes coding for key enzymes in methanotrophs, i.e . the particulate methane monooxygenase (pmoA) and the methanol dehydrogenase (mxaF) . Changes in the biomass of type I and II methanotrophic bacteria in the rice soil were determined by analysis of phospholipid-ester-linked fatty acid (PLFA) biomarkers . The relative contribution of type I and II methanotrophs to the measured methane oxidation activity was determined by labelling of soil samples with 14CH4 followed by analysis of {14C}-PLFAs . CH4 oxidation was repressed by high O2 (20.5%), and enhanced by low O2 (1%) . Depending on the CH4 and O2 mixing ratios, different methanotrophic communities developed with a higher diversity at low than at high CH4 concentration as revealed by PCR-DGGE . However, a prevalence of type I or II populations was not detected . The {14C}-PLFA fingerprints, on the other hand, revealed that CH4 oxidation activity was dominated by type I methanotrophs in incubations with low CH4 mixing ratios (1000 p.p.m.v.) and during initiation of CH4 consumption regardless of O2 or CH4 mixing ratio . At high methane mixing ratios (10 000 p.p.m.v.), type I and II methanotrophs contributed equally to the measured CH4 metabolism . Collectively, type I methanotrophs responded fast and with pronounced shifts in population structure and dominated the activity under all four gas mixtures . Type II methanotrophs, on the other hand, although apparently more abundant, always present and showing a largely stable population structure, became active later and contributed to CH4 oxidation activity mainly under high CH4 mixing ratios. Lipids, 2001 Jan, 36(1), 83 - 7 The first naturally occurring alpha-methoxylated branched-chain fatty acids from the phospholipids of Amphimedon complanata; Carballeira NM et al.; The phospholipid fatty acid composition of the sponge Amphimedon complanata was reinvestigated, and the 2-methoxy-13-methyltetradecanoic acid, 2-methoxy-14-methylpentadecanoic acid, and 2-methoxy-13-methylpentadecanoic acid were identified for the first time in nature . Structure characterization was accomplished by means of gas chromatographic retention times and gas chromatography-mass spectrometry . These acids could have originated from bacteria in symbiosis with the sponge. Dev Biol (Basel), 2000, 103, 3 - 9 Physico-chemical characterization of polysaccharide vaccines; Egan W; An increasing number of sophisticated analytical techniques, including NMR spectroscopy, are currently being applied to the quality control of polysaccharide and polysaccharide-based vaccines . These methodologies are providing more precise and more detailed profiles of these vaccines . NMR spectroscopy also provides a convenient and powerful technique to monitor alterations of the polysaccharide in the production of protein conjugate vaccines. Diabetes Obes Metab, 2001 Feb, 3(1), 33 - 40 Effect of treatment with acarbose and insulin in patients with non-insulin-dependent diabetes mellitus associated with non-alcoholic liver cirrhosis; Gentile S et al.; AIM: Non-insulin-dependent diabetes mellitus (type 2 diabetes) not responding to dietary treatment alone in patients with non-alcoholic liver cirrhosis is characterized by high postprandial hyperglycaemia . The control of postprandial hyperglycaemia in such patients, is generally achieved by the means of progressively higher doses of insulin, with an increasing risk of hypoglycaemia in the late postprandial period . The aim of this study was to evaluate the use of acarbose for the control of postprandial hyperglycaemia in 100 patients with well-compensated liver cirrhosis and type 2 diabetes treated with insulin . METHODS: The study was double blind with randomization of treatments into acarbose (52 patients) vs . placebo (48 patients) with parallel branches over a period of 28 weeks . RESULTS: All patients tolerated the treatments well and no significant variations in liver function tests were observed (< 5% vs . pretreatment) . A significant reduction of several parameters was observed only after acarbose treatment: fasting glycaemia (173 +/- 28 vs . 146 +/- 19 mg/dl; p < 0.01), postprandial glycaemia (230 +/- 24 vs . 148 +/- 20 mg/dl; p < 0.01), mean glycaemia (206 +/- 20 vs . 136 +/- 13 mg/dl; p < 0.01), mean variation (180 +/- 14 vs . 51 +/- 10 mg/dl; p < 0.01), HbA1c (8.9 +/- 0.8 vs . 7.2 +/- 0.5; p < 0.05), C-peptide 2 h after a standard meal (4.5 +/- 1.9 vs . 2.8 +/- 1.7 ng/ml; p < 0.05), whereas the parameters did not change significantly after the placebo . After acarbose treatment a significant increase of intestinal voiding/week (+116% vs . +10%; p < 0.01) and a parallel reduction of blood ammonia levels (-52 +/- 9% vs . -9 +/- 5%; P < 0.01) were observed . CONCLUSIONS: The results clearly document the good tolerability and the absence of toxic effects of acarbose on liver, due to the lack of both intestinal absorption and hepatic metabolism of the drug at doses in the therapeutic range . In fact, acarbose increases the peristalsis movements of the gut, stimulates the proliferation of the saccarolytic bacteria and simultaneously reduces the proliferation of proteolytic bacteria, thus resulting active in the reduction of blood ammonia levels . These effects of acarbose may be advantageously exploited in the treatment of type 2 diabetic patients with well-compensated non-alcholic liver cirrhosis. Biosens Bioelectron, 2000, 15(11-12), 579 - 89 Simultaneous detection of six biohazardous agents using a planar waveguide array biosensor; Rowe-Taitt CA et al.; Recently, we demonstrated that an array biosensor could be used with cocktails of fluorescent antibodies to perform three assays simultaneously on a single substrate, and that multiple samples could be analyzed in parallel . We extend this technology to demonstrate the simultaneous analysis of six samples for six different hazardous analytes, including both bacteria and protein toxins . The level of antibody cross-reactivity is explored, revealing a possible common epitope in two of the toxins . A panel of environmental interferents was added to the samples; these interferents neither prevented the detection of the analytes nor caused false-positive responses. Cell Mol Life Sci, 1999 Dec, 56(11-12), 918 - 44 Plant mitochondrial carriers: an overview; Laloi M; In the two last decades, biochemical studies using mitochondrial swelling experiments or direct solute uptake in isolated mitochondria have lead to the identification of different transport systems at the level of the plant mitochondrial inner membrane . Although most of them have been found to have similar features to those identified in animal mitochondria, some differences have been observed between plant and animal transporters . More recently, molecular biology studies have revealed that most of the mitochondrial exchanges are performed by nuclear encoded proteins, which form a superfamily . Members of this family have been reported in animals, yeast as well as plants . This review attempts to give an overview of the present knowledge concerning the biochemical and molecular characterisation of plant members of the mitochondrial carrier family and, when possible, a comparison with carriers from other organisms. Int J Syst Evol Microbiol, 2001 Jan, 51(Pt 1), 27 - 34 Determination of the systematic position of the genus Asticcacaulis Poindexter by a polyphasic analysis; Abraham WR et al.; The genus Asticcacaulis, to date, comprises two species of unicellular, stalked bacteria, developing a stalk at a site which is not coincidental with the centre of the pole of the cell . Multiplication is similar to that demonstrated by the prosthecate species of the genera Caulobacter, Brevundimonas and Maricaulis . A polyphasic approach, comprising 16S rRNA gene sequencing, lipid analysis and NaCl tolerance characterizations, was used to clarify the taxonomy of the two Asticcacaulis species . From the analysis of the 16S rRNA gene sequences, a close phylogenetic relationship between the species that comprise the genera Asticcacaulis, Caulobacter and Brevundimonas could be deduced wherein the three genera form three distinct branches . The individual genera could also be discerned by different characteristic polar lipids . The species of Asticcacaulis differed from species of Caulobacter and Brevundimonas by the lack of 1,2-diacyl-3-O-{6'-phosphatidyl-alpha-D-glucopyranosyl}glycerol . They also did not contain 1,2-di-O-acyl-3-O-{D-glucopyranosyl-(1-->4)-alpha-D-glucuronopyranosyl}glycerol, which is found in most Brevundimonas species but not in strains of the genus Caulobacter . The morphological differences seen between the two species Asticcacaulis excentricus and Asticcacaulis biprosthecium are mirrored by the observed 16S rDNA sequence similarity value of 95.3%, which is relatively low compared to the interspecies similarity values observed within the genera Brevundimonas or Caulobacter. J Periodontol, 2001 Jan, 72(1), 74 - 8 Relationship of sulcular sulfide level to severity of periodontal disease and BANA test; Morita M et al.; BACKGROUND: Volatile sulfur compounds (VSC), such as hydrogen sulfide and methyl mercaptan, are toxic metabolites produced by periodontal pathogens . Their relationship to periodontal disease severity is not yet fully understood . Hence, the aims of this study were to: 1) examine the relationship between sulcular sulfide (pS) levels and severity of periodontal disease and 2) examine the link between pS level and the BANA (benzoyl-DL-arginine-naphthylamide) test . METHODS: Seventy systemically healthy subjects with a mean age of 53.0 +/- 13.8 years participated . Three sites were selected from each subject based upon radiographic bone loss (RBL): RBL < 2 mm, healthy; RBL > or = 2 to < 4, low to moderate; RBL > or = 4 mm, severe . Periodontal parameters, probing depth (PD), clinical attachment level (CAL), and bleeding on probing (BOP), were recorded . The pS level was measured using a portable sulfide monitor in a digital score ranging from 0.0 (< 10(-7) M of S) to 5.0 (> or = 10(-2) M of S) in increments of 0.5 . The presence of specific bacteria in subgingival plaque was detected using BANA test . RESULTS: The mean pS level was 0.10 +/- 0.23, 0.36 +/- 0.48, and 1.10 +/- 0.87 for healthy, low to moderate, and severe disease sites, respectively, and was statistically different (P<0.001) . The pS level was positively correlated with the BANA test, and was higher in untreated subjects than maintenance subjects (P<0.01) . CONCLUSIONS: The pS level may be a potential indicator for detecting severity of periodontal disease and identifying bacteria that are capable of hydrolyzing BANA. J Periodontol, 2001 Jan, 72(1), 65 - 73 Fluid dynamics of gingival tissues in transition from physiological condition to inflammation; Del Fabbro M et al.; BACKGROUND: An increase in gingival sulcular fluid filtration is a common clinical sign of early gingivitis . The aim of this study was to describe the fluid dynamics of the gingival interstitial tissues at the level of the sulcus in the transition towards inflammation . METHODS: In 13 anesthetized rabbits, a silk ligature was placed around incisors close to the gingival margin, in order to prevent mechanical cleaning of plaque deposition . After 2 to 7 days, animals were anesthetized and interstitial fluid pressure measured using glass micropipettes connected to a servonull pressure system at the level of the free and attached gingiva . RESULTS: Interstitial pressure was 3.8 +/- 2.9 cmH2O, significantly higher than the normal physiological value (about -1 cmH2O) . Colloid osmotic pressure of interstitial fluid samples collected using the wick technique was measured using an osmometer whose membrane had a molecular cut-off of 30 kD and averaged 12.8 +/- 2.8 cmH2O (unchanged relative to control) . Mean gingival sulcular fluid flow, measured by placing a PE tube (0.5 mm OD, 0.28 mm ID) in the sulcus, was 0.16 +/- 0.12 microl/h; the mean colloid osmotic pressure was 13.6 +/- 6.6 cmH2O, corresponding to a protein concentration of approximately 2.8 g/dl . Proteins of gingival fluid may leak from inflamed gingival interstitium or derive from bacteria of dental plaque . Histological analysis of gingival biopsies showed neutrophilic polymorphonuclear leukocyte infiltrates in both the dermis and epidermis layer . CONCLUSIONS: Based on hydraulic and colloid osmotic data, the Starling pressure gradient favored filtration from gingival interstitium to the sulcular space, a condition opposite to that observed in healthy gingiva where fluid filtration is absent. Dis Aquat Organ, 2000 Dec 21, 43(3), 199 - 209 Mortality and kidney histopathology of chinook salmon Oncorhynchus tshawytscha exposed to virulent and attenuated Renibacterium salmoninarum strains; O'Farrell CL et al.; An isolate of Renibacterium salmoninarum (strain MT 239) exhibiting reduced virulence in rainbow trout Oncorhynchus mykiss was tested for its ability to cause bacterial kidney disease (BKD) in chinook salmon Oncorhynchus tshawytscha, a salmonid species more susceptible to BKD . Juvenile chinook salmon were exposed to either 33209, the American Type Culture Collection type strain of R . salmoninarum, or to MT 239, by an intraperitoneal injection of 1 x 10(3) or 1 x 10(6) bacteria fish(-1), or by a 24 h immersion in 1 x 10(5) or 1 x 10(7) bacteria ml(-1) . For 22 wk fish were held in 12 degrees C water and monitored for mortality . Fish were sampled periodically for histological examination of kidney tissues . In contrast to fish exposed to the high dose of strain 33209 by either injection or immersion, none of the fish exposed to strain MT 239 by either route exhibited gross clinical signs or histopathological changes indicative of BKD . However, the MT 239 strain was detected by the direct fluorescent antibody technique in 4 fish that died up to 11 wk after the injection challenge and in 5 fish that died up to 20 wk after the immersion challenge . Viable MT 239 was isolated in culture from 3 fish that died up to 13 wk after the immersion challenge . Total mortality in groups injected with the high dose of strain MT 239 (12%) was also significantly lower (p < 0.05) than mortality in groups injected with strain 33209 (73 %) . These data indicate that the attenuated virulence observed with MT 239 in rainbow trout also occurs in a salmonid species highly susceptible to BKD . The reasons for the attenuated virulence of MT 239 were not determined but may be related to the reduced levels of the putative virulence protein p57 associated with this strain. Nature, 2001 Jan 25, 409(6819), 497 - 500 Riverine export of aged terrestrial organic matter to the North Atlantic Ocean; Raymond PA et al.; Global riverine discharge of organic matter represents a substantial source of terrestrial dissolved and particulate organic carbon to the oceans . This input from rivers is, by itself, more than large enough to account for the apparent steady-state replacement times of 4,00-6,000 yr for oceanic dissolved organic carbon . But paradoxically, terrestrial organic matter, derived from land plants, is not detected in seawater and sediments in quantities that correspond to its inputs . Here we present natural 14C and 13C data from four rivers that discharge to the western North Atlantic Ocean and find that these rivers are sources of old (14C-depleted) and young (14C-enriched) terrestrial dissolved organic carbon, and of predominantly old terrestrial particulate organic carbon . These findings contrast with limited earlier data that suggested terrestrial organic matter transported by rivers might be generally enriched in 14C from nuclear testing, and hence newly produced . We also find that much of the young dissolved organic carbon can be selectively degraded over the residence times of river and coastal waters, leaving an even older and more refractory component for oceanic export . Thus, pre-ageing and degradation may alter significantly the structure, distributions and quantities of terrestrial organic matter before its delivery to the oceans. Int J Dev Biol, 2000 Dec, 44(8), 861 - 6 Morphological chimeras of larvae and adults in a hydrozoan--insights into the control of pattern formation and morphogenesis; Kroiher M; In the marine hydroid Hydractinia echinata, metamorphosis transforms the spindle-shaped larva into a primary polyp . It bears a hypostome with a ring of tentacles at its apical end, a gastric region in the middle and stolons at the base . In nature, metamorphosis is induced in response to external stimuli provided by bacteria . These stimuli can be replaced by artificial inducers, one of which is heat shock . Among heat shock treated stages are those undergoing complete metamorphosis but also specimens forming chimeras of different developmental stages . In the chimeric larvae, the posterior is transformed into the apical hypostome of the adult polyp while the anterior part of the larva persists as larval tissue . After transverse sectioning, these stage chimeras regenerate the missing body parts with respect to the nature of the tissue at the wound surface . This shows that the decision to make larva or polyp morphology depends not on the majority of the tissue in the original body section, but on stage specificity within the regenerating animal part . Single cells can escape from this general rule, since RFamide nerve cells which usually differentiate in polyp tissue appear in regenerated larval tails of sectioned stage chimeras . The results indicate that the pattern-forming system of the larva and of the adult have features in common . The primary signals controlling patterning along the anterior-posterior axis in larvae and the apical-basal axis in polyps arethus likelyto be the same while the interpretation of these primary signals by the individual cells changes during metamorphosis. Ned Tijdschr Geneeskd, 2001 Jan 20, 145(3), 113 - 5 {Two children with extrapulmonary symptoms due to tuberculosis}; Slingerland AS et al.; Two patients came to their general practitioner for relatively minor problems: a 4-year-old boy came with a red eye and a 10-year-old girl with red foot soles . They came from Pakistan and Vietnam respectively . Their symptoms were due to tuberculosis, which diagnosis was established by Mantoux test and culture of a stomach aspirate . They were treated accordingly with isoniazid, rifampicin and pyrazinamide and with isoniazid, rifampicin and ethambutol respectively . These cases stress the importance of knowledge of the extrapulmonary manifestations of tuberculosis . As treatment exists and adequate treatment can diminish the reservoir of tuberculosis bacteria, early diagnosis can prevent the morbidity, spread and mortality of tuberculosis. Parasitol Res, 2001 Feb, 87(2), 163 - 8 Analysis for Giardia cysts and Cryptosporidium oocysts in water samples from small water systems in Taiwan; Hsu BM et al.; Giardia and Cryptosporidium have emerged as waterborne pathogens of concern . Twenty-six water samples were collected from small water systems in Taiwan and checked for the occurrence of both parasites . Water quality parameters and characteristics of the sampling sites were also recorded . The frequencies of occurrence for Giardia and Cryptosporidium were 46.2% for each; and their mean concentrations were 79.5 cysts/100 l and 22.1 oocysts/100 l, respectively . The concentrations of oocysts and heterotrophic bacteria exhibited the highest correlation and followed the concentrations of the two protozoa . The water samples from sites with filtration devices had a lower oocyst concentration than those from sites without filtration devices, while no significant difference was found for cysts . The level of each parasite had no direct relationship with altitude . The cyst concentrations increased proportionally with the consumer population using the water systems . Risk assessment of the parasitic infections suggests that setting up disinfection devices in the small water systems would be needed. Immunobiology, 2000 Nov, 202(5), 493 - 507 Superantigen-dependent accelerated death of bovine neutrophilic granulocytes in vitro is mediated by blood mononuclear cells; Schuberth HJ et al.; While classical interactions of bacterial superantigens (SAgs) with antigen presenting cells and T cells have been studied intensively, the potential interactions of SAgs with granulocytes (PMNs) have gained much less attention . We investigated if in the bovine system SAgs have any direct or indirect influence on the fate of granulocytes, which are among those cells primarily responsible for the elimination of superantigen-producing bacteria . The tested SAgs (SEA, SEB) had no apparent direct effect on PMN viability (neutrophils and eosinophils) . However, in the presence of blood mononuclear cells (MNCs), SAgs led to an accelerated death of neutrophils but not of eosinophils . Compared to medium controls, in SAg-stimulated cultures only about 20-50% of the neutrophils survived after 24 hours in vitro . Accelerated death of neutrophils required the presence of at least 10% MNC and started between 2.5-24 h after initiation of the co-culture between MNC and PMN . Minimal effective SEA concentrations ranged between 10-100 pg/l (SEB 0.1-10 ng/l) . The effect could be mimicked by culture supernatants of SAg-stimulated MNCs, suggesting that direct cell-cell interactions are not required for the killing . In the human system, where we tested the role of TNF-alpha, an antibody specific for this cytokine was not able to abolish the death of human neutrophils . Brefeldin A, an inhibitor of golgi transport and cytokine secretion, which blocked the SAg-induced activation of bovine MNC did not abolish the killing of neutrophils . Blocking of nitric oxide generation or PGE2 synthesis also could not alter the SAg-induced killing of bovine neutrophils . The observed indirect negative effects of SAgs on neutrophils may provide new insights in mechanisms by which superantigens modulate the hosts immune response. Anticancer Res, 2000 Nov-Dec, 20(6B), 4347 - 50 Failure of detection of the tyrosine to histidine substitution at the residue 33 of thymidylate synthase in human colorectal cancer . A preliminary study; Sanguedolce R et al.; Structural changes in the macromolecular targets of pharmacological agents can result in alterations in the efficacy of these agents . In previous studies Berger et al . (1) identified a variant structural form of thymidylate synthase (TS) that is associated with relative resistance to 5-fluoro-2'-deoxyuridine, in a human colonic tumor cell line . They observed that expression of the variant TS, which differs from the normal form by a tyrosine to histidine substitution at residue 33, confers a 4-fold level of drug resistance in mammalian cells, as well as in bacteria . Now we report on the use of RT-PCR techniques to see if that variant TS form could be present in human samples from patients who underwent surgery for primary colorectal cancer and been previously untreated and to try to find relationships between that hypothetical variant TS form and the 5-Fluorouracil treatment . The possible role of Tyr-33 in 5-fluoropyrimidine-mediated inhibition of TS is discussed. Pathol Biol (Paris), 2000 Dec, 48(10), 906 - 8 {Efficacity of antiseptic products}; Arnaud P et al.; Chemical antiseptics are used in specified conditions . This work studied the actual standards to evaluate the activity of antiseptics . Afterward, the main indications of antiseptics are summarized. J Eur Acad Dermatol Venereol, 2000 Jul, 14(4), 296 - 7 Activation of cutaneous sarcoidosis following Mycobacterium marinum infection of skin; Gudit VS et al.; Sarcoidosis has long been associated with mycobacterial infection, especially with Mycobacterium tuberculosis, although a causal association has not been proven . Atypical mycobacteria have also been implicated in causing sarcoidosis, but there is as yet no conclusive evidence . We report the activation of cutaneous sarcoidosis following infection with M . marinum, raising further questions about the role of these bacteria in causing this chronic granulomatous disorder. Z Naturforsch {C}, 2000 Nov-Dec, 55(11-12), 991 - 1003 Cyanophora paradoxa: nucleotide sequence and phylogeny of the nucleus encoded muroplast fructose-1,6-bisphosphate aldolase; Nickol AA et al.; Immunoscreening of a C . paradoxa expression library against water soluble muroplast ("cyanelle") proteins resulted in isolation of a clone encoding the nucleus-encoded muroplast class-II fructose-1,6-bisphosphate aldolase (class-II FBA) . Its nucleotide sequence was determined . The 1432 bp insert, derived from a single-copy gene transcript, bears a reading frame of 1206 bp in length, representing 402 amino acids with 346 amino acids of mature protein . The leading amino acids match structural features necessary for precursor import across chloroplast envelope membranes . In phylogenetic tree topology, the investigated mature FBA clusters within type B FBAs with Synechocystis sp . as nearest neighbor . This is the first report of a Type B class-II FBA sequence of plastids. Z Naturforsch {C}, 2000 Nov-Dec, 55(11-12), 943 - 7 A study on the heterogeneity of the light-harvesting complex II from Ectothiorhodospira sp . after acid/chaotropic treatment; Buche A et al.; The light-harvesting complex II of the purple bacteria has two strong near infrared electronic absorption bands, around 800 (B800) and 850 (B850) nm, arising from the Qy transitions of bacteriochlorophyll a . It was previously reported that under some specific acid/chaotropic conditions the B850 bacteriochlorophylls of the light-harvesting complex II of Ectothiorhodospira sp . are strongly reorganised . Part of these pigments absorbs at 843 nm while another set absorbs around 858 nm . The current work should investigate whether a mix of two different complexes could generate the 843- and 858-nm bands . Acid/chaotropic conditions inducing the reorganisation of B850 were reproduced on a sample bound to an ionic-exchange column . The chromatographic pattern was found strongly homogeneous . The findings indicate that the heterogeneity of the reorganised B850 results from two forms of differently structured bacteriochlorophylls bound to the same polypeptide backbone. Quintessence Int, 2000 Sep, 31(8), 579 - 89 Pulpotomy reconsidered: application of an adhesive system to pulpotomized permanent primate pulps; Hafez AA et al.; OBJECTIVE: This study was undertaken to compare the healing response of permanent primate pulps to pulpotomy procedures following hemorrhage control and adhesive hybridization to their response after conventional treatments . METHOD AND MATERIALS: Forty-two cavities were placed throughout the dentitions of 4 adult monkeys . In 24 teeth, following mechanical bur exposure and pulpotomy, hemorrhage was controlled with application of 3% sodium hypochlorite . The cavity was rinsed and the enamel-dentin-pulp surface was restored with an adhesive system for 6 and 7 months . Calcium hydroxide, formocresol, and resin-modified glass-ionomer cement were placed as conventional treatments in 18 teeth for 70 days and cavities were sealed with resin-modified glass-ionomer cement . Following perfusion fixation, tissues were demineralized, sectioned, stained, and histologically graded using defined criteria . RESULTS: Of 24 adhesive system pulps, 10 showed no or minimal pulpal response, 1 showed an acute response, 6 showed a chronic response, 2 showed a severe response, and 5 showed compartmentalized zones of localized necrosis . Only 8 adhesive system pulps showed stained bacteria associated with inflamed tissues . Thirteen adhesive system pulps showed dentin bridging directly at the adhesive system interface . Calcium hydroxide-treated specimens showed healing and dentin formation, while resin-modified glass-ionomer cement and formocresol treatments failed to result in any bridging . Apical tissues in all adhesive-treated specimens showed normal pulps and primary odontoblasts along their entire walls . CONCLUSION: Permanent pulps without periapical radiolucencies may survive pulpotomy, provided that hemorrhage is properly controlled and the pulp-restoration interface is hybridized to exclude all microleakage. Spec Care Dentist, 2000 Jan-Feb, 20(1), 18 - 22 Effects of short professional mechanical tooth-cleaning (PMTC) program in young adults with mental disabilities; Mori Y et al.; We evaluated the usefulness of a short professional mechanical tooth-cleaning (PMTC) program to improve periodontal conditions and caries susceptibility in 10 young adult patients with mental and/or physical disabilities . The PMTC program was carried out once on each of 6 sextants of the full mouth during 6 visits at two-week intervals . Even one treatment with PMTC was found to be significantly effective in reducing the probing depth in eight of the 10 subjects . A reduction in the total number of bleeding sites on probing was also clearly observed in all subjects . Moreover, the debris index was reduced in nine subjects by the PMTC program . Although caries susceptibility was improved, albeit very slowly, by PMTC, the Cariostat pH values showed no consistent tendency . The effects lasted for more than 6 weeks . Analysis of these results suggests that the PMTC program can be effective in adults with mental disabilities, especially in reducing gingival inflammation. Environ Pollut, 2001, 112(1), 11 - 7 Comparative metabolism of phenanthridine by carp (Cyprinus carpio) and midge larvae (Chironomus riparius); Bleeker EA et al.; Abiotic transformation of azaarenes in the environment has been analysed extensively, but metabolism is less well described . To further elucidate preliminary observations of interspecific differences in azaarene metabolism by aquatic organisms, phenanthridine biotransformation by midge larvae and carp was studied . In both experiments, 6(5H)-phenanthridinone (phenanthridone) was found as an important metabolite . The fish were clearly capable of metabolising phenanthridine, but in the midge experiment the metabolite was principally formed by bacteria growing on the food and not by the midges . Phenanthridone itself was further degraded to non-observed compounds in both experiments, due to bacteria and midges acting together in the midge experiment, and by carp in the fish experiment . Internal concentrations of phenanthridine and phenanthridone were non-detectable in the midge larvae, but concentrations of both compounds in carp organs suggested a major role of bile and liver . Since phenanthridone did not account for all phenanthridine loss, it was suggested that, apart from phenanthridone degradation, other metabolic pathways may play a role . This study clearly demonstrates the importance of interspecies differences in metabolism, which should not be neglected in risk assessment. J Dent Res, 2000 Dec, 79(12), 1948 - 54 Butyric-acid-induced apoptosis in murine thymocytes and splenic T- and B-cells occurs in the absence of p53; Kurita-Ochiai T et al.; Butyric acid, an extracellular metabolite from periodontopathic bacteria, induces apoptosis in murine thymocytes, splenic T-cells, and human Jurkat T-cells . The present study examines the contributions of apoptosis-related proteins (Bcl-2, Bcl-XL, Bax, and p21WAF1/CIP1) in the regulation of T-cell death induced by butyric acid, using p53 knock-out (p53-/-) and wild-type (p53+/+) mice . The results of a DNA fragmentation assay indicated that thymocytes, splenic T-cells, and B-cells from p53-/- mice were susceptible to butyric-acid-induced apoptosis to a degree similar to those from p53+/+ mice . Moreover, butyric acid significantly induced apoptosis in lymphocytes from both p53+/+ and p53-/- mice in a concentration- and time-dependent fashion . Experiments with fractionated subpopulations of splenic T-cells revealed that DNA fragmentation was equally observed in CD4+ and CD8+ splenic T-cells from both p53+/+ and p53-/- lymphocytes . Activation of caspase-3, caspase-6, and caspase-8, but not of caspase-1, in butyric-acid-induced T-cell apoptosis occurred regardless of the presence of p53 . Western blotting analysis of splenic T-cells showed that butyric acid treatment decreased Bcl-2 and Bcl-XL expressions in p53+/+ and p53-/- cells . Splenic T-cells had barely detectable Bax and p21WAF1/CIP1, regardless of whether butyric acid and/or p53 was present . These results suggest that butyric-acid-mediated apoptosis of murine T-cells takes place via a pathway that is independent of p53, and is followed by the p53-regulated proteins Bax and p21WAF1/CIP1, which lower the levels of the apoptosis antagonists Bcl-2 and Bcl-XL in cells. Comp Med, 2000 Dec, 50(6), 666 - 72 Diagnosis and management of atypical Mycobacterium spp . infections in established laboratory zebrafish (Brachydanio rerio) facilities; Astrofsky KM et al.; Two established zebrafish colonies experienced increased mortality and decreased reproductive performance . Initial examination of several fish from one facility revealed hyperemic gills, petechia around the opercula, abdominal distention, and emaciation . Affected fish had congested liver with inflammation and multifocal hepatic necrosis . Large numbers of acid-fast-positive, rod-shaped bacteria were evident in multiple tissues and the blood . Mycobacterium fortuitum was subsequently isolated from several fish . Zebrafish from the second facility had skin erosions and ulceration along the flank just caudal to the pectoral fins . Large numbers of acid-fast-positive, rod-shaped bacteria were observed within the necrotic centers of well-demarcated, multifocal granulomas in gonads, liver, and peritoneum from affected fish . Mycobacterium abscessus and M . chelonae were isolated and identified biochemically . Definitive diagnosis in these outbreaks was obtained by culture on selective media . Because Mycobacterium spp . grow extremely slowly and positive confirmation may require 45 to 60 days, Mycobacterium species-specific polymerase chain reaction analysis was used to provide a rapid screening assay for Mycobacterium spp . as well as for verification of culture results . To our knowledge, this is the first documentation of mycobacterial infection in laboratory-maintained zebrafish and provides guidelines for diagnosis, management, and prevention of atypical mycobacteriosis in laboratory zebrafish colonies. Ukr Biokhim Zh, 2000 May-Jun, 72(3), 120 - 3 {A rapid method for determining the fatty acid composition of lipid A}; Tarnavs'ka NM et al.; Lipid A is the most conservative part of LPS . Its fatty acids composition can serve as an important taxonomic marker of bacteria . The isolation of LPS and studying their chemical composition are difficult and protracted procedure . We propose the rapid method of determining the prevailed fatty acids of lipid A without isolation of LPS from the cell . The essence of the method is in the release of cell from the lipids which are not components of LPS . These lipids, in contrast to the lipid A, are more easily extractable from the cell structures . The fatty acids, which prevailed in the lipid-free cells, are the structural components of lipid A. J Mol Microbiol Biotechnol, 2001 Jan, 3(1), 95 - 101 A sigmaB-like factor responsible for carotenoid biosynthesis in Streptomyces griseus; Lee HS et al.; Self-cloning experiments with a high-copy-number plasmid and Streptomyces griseus IFO13350 led to the cloning of a 11-kb DNA fragment that conferred yellow pigment production on the host . The cloned fragment contained a gene cluster for carotenoid biosynthesis, in which two polycistrons, crtE (encoding geranylgeranyl pyrophosphate synthase)-crtI (phytoene dehydrogenase)-crtB (phytoene synthase)-crtV (functionally unknown methyltransferase-like protein) and crtY (lycopene cyclase)-crtT (functionally unknown methyltransferase-like protein)-crtU (beta-carotene dehydrogenase), were present in a convergent way . Since strain IFO13350 produced no detectable amount of carotenoids, an increase in the copy number of the crt gene cluster led to production of carotenoids at a detectable level . Overexpression of the stress-responsive sigmaB-like protein CrtS from Streptomyces setonii also activated the cryptic crt genes in S . griseus and conferred pigmentation . A CrtS homologue (sigmaCrtS) in S . griseus, which was predicted by a computer-aided homology search, caused carotenogenesis to the same extent as CrtS of S . setonii, indicating that the two sigmaB-like proteins were functionally the same . Yellow pigment production by S . griseus containing crtS under the control of a strong promoter on a high-copy-number plasmid resulted from activation of transcription of the crt genes, because overexpression of sigmaCrtS in S . griseus led to transcriptional activation of the promoters in front of crtE and crtY . S1 nuclease mapping showed that crtS itself was transcribed at a low level under the laboratory conditions, which may account for undetectable production of carotenoids . The crt genes were suggested to locate very near one end of the linear chromosome, since they were completely deleted in mutant HH1 having large deletions at both ends . The gene organization of crt in S . griseus is similar to that in S . coelicolor A3(2) where the whole crt gene set is near one end of the chromosome. J Endod, 2000 May, 26(5), 295 - 8 The radicular groove: its potential clinical significance; Simon JH et al.; This report examines three clinical cases of root-filled teeth with primary endodontic lesions . During endodontic surgery, an area of incomplete root bifurcation beginning in the coronal or middle third of the root surface and terminating at or near the apical foramen were observed . The radicular grooves of two teeth were eliminated using a round bur ("saucerization"), and the resulting defect was filled with a bone substitute or calcium sulfate and covered by an absorbable collagen membrane . The other tooth was extracted, the groove was eliminated with a similar technique, and the tooth was replanted . Bacteria have been reported in chronic apical lesions . Our observations suggest that after conventional endodontic therapy, the etiology of a nonresolving primary endodontic lesion may be bacteria of endodontic origin sequestered within the protective confines of an apical-radicular groove. J Endod, 2000 Apr, 26(4), 217 - 20 Whole genomic DNA probe for detection of Porphyromonas endodontalis; Nissan R et al.; The purpose of the present study was to develop a DNA probe for Porphyromonas endodontalis . Pure cultures of P . endodontalis were grown in TYP medium, in an anaerobic chamber . DNA was extracted from the P . endodontalis and labeled using the Genius System by Boehringer Mannheim . The labeled P . endodontalis DNA was used in dot-blot hybridization reactions with homologous (P . endodontalis) and unrelated bacterial samples . To determine specificity, strains of 40 other oral bacterial species (e.g . Porphyromonas gingivalis, Porphyromonas asaccharolytica, and Prevotella intermedia) were spotted and reacted with the P . endodontalis DNA probe . None of the panel of 40 oral bacteria hybridized with the P . endodontalis probe, whereas the blot of the homologous organism showed a strong positive reaction . To determine the sensitivity of the probe, dilutions of a P . endodontalis suspension of known concentration were blotted onto a nylon membrane and reacted with the probe . The results of our investigation indicate that the DNA probe that we have prepared specifically detects only P . endodontalis and can detect at least 3 x 10(4) cells. J Vet Med A Physiol Pathol Clin Med, 2000 Dec, 47(10), 617 - 26 Na(+)-dependent transport of D-xylose by bovine intestinal brush border membrane vesicles (BBMV) is inhibited by various pentoses and hexoses; Scharrer E et al.; To detect whether pentoses and hexoses occurring in rumen bacteria or in hemicellulose ingested with feed and partly released in the small intestine have an affinity for the Na(+)-dependent glucose transporter of the bovine intestinal brush border membrane (BBM), we investigated whether these monosaccharides inhibit Na(+)-dependent transport of 14C-labelled D-xylose across the BBM using brush border membrane vesicles (BBMV) isolated from the mid-jejunum of cows . We used D-xylose as the transport substrate, because it has a low affinity for the Na(+)-dependent glucose transporter and thus its uptake into BBMV is more efficiently competitively inhibited by other sugars than that of D-glucose . D-Ribose, D-mannose and L-rhamnose occurring in rumen bacteria significantly inhibited Na(+)-dependent uptake of D-xylose into BBMV, but their inhibitory effect was less than that of D-glucose, D-xylose and phlorizin . This also applied to L-arabinose (and D-arabinose), which is, like D-xylose and D-galactose, a constituent of hemicellulose, and to 2-deoxy-D-glucose . Of all monosaccharides tested, only D-fructose did not affect Na(+)-dependent D-xylose transport . It is concluded that some pentoses and hexoses occurring in rumen bacteria (D-ribose, D-mannose and L-rhamnose) or hemicellulose (L-arabinose and D-xylose) have a low affinity for the Na(+)-dependent glucose transporter of the bovine BBM and may therefore be absorbed from the jejunum when released in the small intestine. J Food Prot, 2001 Jan, 64(1), 120 - 31 Dietary strategies to counteract the effects of mycotoxins: a review; Galvano F et al.; We reviewed various dietary strategies to contain the toxic effects of mycotoxins using antioxidant compounds (selenium, vitamins, provitamins), food components (phenolic compounds, coumarin, chlorophyll and its derivatives, fructose, aspartame), medicinal herbs and plant extracts, and mineral and biological binding agents (hydrated sodium calcium aluminosilicate, bentonites, zeolites, activated carbons, bacteria, and yeast) . Available data are primarily from in vitro studies and mainly focus on aflatoxin B1, whereas much less information is available about other mycotoxins . Compounds with antioxidant properties are potentially very efficacious because of their ability to act as superoxide anion scavengers . Interesting results have been obtained by food components contained in coffee, strawberries, tea, pepper, grapes, turmeric, Fava tonka, garlic, cabbage, and onions . Additionally, some medicinal herbs and plant extracts could potentially provide protection against aflatoxin B1 and fumonisin B1 . Activated carbons, hydrated sodium calcium aluminosilicate, and bacteria seem to effectively act as binders . We conclude that dietary strategies are the most promising approach to the problem, considering their limited or nil interference in the food production process . Nevertheless, a great research effort is necessary to verify the in vivo detoxification ability of the purposed agents, their mode of action, possible long-term drawbacks of these detoxification-decontamination procedures, and their economical and technical feasibility. Parasitology, 2001 Jan, 122 Pt 1, 93 - 103 A phylogenetic analysis of filarial nematodes: comparison with the phylogeny of Wolbachia endosymbionts; Casiraghi M et al.; Infection with the endosymbiotic bacteria Wolbachia is widespread in filarial nematodes . Previous studies have suggested concordance between the phylogeny of Wolbachia with that of their nematode hosts . However, there is only one published molecular phylogenetic study of filarial species, based on the 5S rRNA gene spacer . The phylogeny proposed by this study is partially incongruent with previous classifications of filarial nematodes, based on morphological characters . Furthermore, both traditional classifications and molecular phylogenies are, in part, inconsistent with the phylogeny of Wolbachia . Here we report mitochondrial cytochrome oxidase I (COI) gene sequences for 11 species of filaria and for another spirurid nematode which was included as an outgroup . In addition, 16S rRNA, wsp and ftsZ gene sequences were generated for the Wolbachia of several filarial species, in order to complete the available data sets and further resolve the phylogeny of Wolbachia in nematodes . We used these data to evaluate whether nematode and Wolbachia phylogenies are concordant . Some of the possible phylogenetic reconstructions based on COI gene were congruent with the phylogeny of Wolbachia and supported the grouping of the rodent filaria Litomosoides sigmodontis with the lymphatic filariae (i.e . Brugia spp . and Wuchereria spp.) and the sister group relationship of Dirofilaria spp . and Onchocerca spp . However, the placement of the Wolbachia-free filaria Acanthocheilonema viteae is ambiguous and dependent on the phylogenetic methods used. Parasitology, 2001 Jan, 122 Pt 1, 111 - 20 Cuticle heterogeneity as exhibited by Pasteuria spore attachment is not linked to the phylogeny of parthenogenetic root-knot nematodes (Meloidogyne spp.); Davies KG et al.; The cuticle is a major barrier prohibiting the infection of nematodes against micro-organisms . The attachment of bacterial spores of the nematode hyperparasite Pasteuria penetrans (PP1) to field populations of root-knot nematodes (RKN, Meloidogyne spp.) from Burkino Faso, Ecuador, Greece, Malawi, Senegal and Trinidad and Tobago were assayed in standard attachment tests . The attachment of spore population PP1 to different field populations of root-knot nematode showed that the rates of attachment differed between countries . Similar tests were also undertaken on P . penetrans spores from these countries against 2 species of RKN, M . incognita and M . arenaria . The results showed a high degree of variability in spore attachment with no clear distinction between the 2 species of nematode . It has been hypothesized that Pasteuria spore attachment is linked to nematode species designations and this study clearly shows that this is not the case . Further tests showed that variation in spore attachment was not linked to nematode phylogeny . The results therefore beg the question of how do parthenogenetic root-knot nematodes maintain cuticle variability in the face of such an aggressive hyperparasite. Proc R Soc Lond B Biol Sci, 2000 Dec 22, 267(1461), 2511 - 6 Antigenic role of the endosymbionts of filarial nematodes: IgG response against the Wolbachia surface protein in cats infected with Dirofilaria immitis; Bazzocchi C et al.; Filarial nematodes harbour intracellular endosymbiotic bacteria, which have been assigned to the genus Wolbachia . These bacteria appear to play an important role in the pathogenesis of filarial diseases through their lipopolysaccharides . In view of the presence of Wolbachia endosymbionts in the body of filarial nematodes, one might also expect that proteins from these bacteria play an antigenic role in humans and animals affected by filariases . To test this hypothesis, we produced in recombinant form the surface protein WSP and a portion of the cell-cycle protein FTSZ from the Wolbachia of Dirofilaria immitis . Western immunoblot assays were then performed using cat sera to test the immunogenicity of these proteins . Sera were collected from owners' cats, which were either sero-negative or sero-positive for D . immitis and from cats before and after experimental infection with D . immitis . FTSZ was recognized in Western blots by sera from both positive and negative cats and from both uninfected and experimentally infected cats . WSP was recognized only by sera from positive cats and from cats experimentally infected with D . immitis; this protein was not recognized by sera from negative cats and from cats before experimental infection with D . immitis . The results of Western blot assays on WSP thus support the hypothesis that infection with filarial nematodes induces the production of antibodies against Wolbachia proteins. Mil Med, 2001 Jan, 166(1), 85 - 9 Periodontal disease and its association with systemic disease; Fowler EB et al.; Periodontal diseases are oral disorders characterized by inflammation of the supporting tissues of the teeth . Usually, periodontitis is a progressively destructive loss of bone and periodontal ligament (loss of the attachment apparatus of the teeth) . Periodontitis has documented risk factors, including but not limited to specific plaque bacteria, smoking, and diabetes mellitus . Initially, the link between systemic disease and periodontal diseases was thought to be unidirectional . Currently, there is increasing evidence that the relationship between these entities may be bidirectional . Recent case-control and cross-sectional studies indicate that periodontitis may confer a 7-fold increase in risk for preterm low birth weight infants and a 2-fold increase in risk for cardiovascular disease . These early reports indicate the potential association between systemic and oral health . Additionally, these studies support the central hypothesis that periodontal disease involves both a local and a systemic host inflammatory response . This knowledge of disease interrelationships may prove vital in intervention strategies to reduce patient risks and prevent systemic disease outcomes . Based on the current evidence of the periodontal-systemic disease connection, the purpose of this report is to help establish the groundwork for closer communication between physicians and periodontists in the military health care setting. J Pharm Pharmacol, 2000 Dec, 52(12), 1563 - 8 Baicalin, the predominant flavone glucuronide of scutellariae radix, is absorbed from the rat gastrointestinal tract as the aglycone and restored to its original form; Akao T et al.; When baicalin was orally administered to conventional rats, it was detected in their plasma for 24 h after administration, but baicalein, the aglycone of baicalin, was not detected . However, when baicalin was given to germ-free rats, only a small amount of baicalin was detected in their plasma within 2 h after the administration, its AUC0-lim (the area under the concentration-time curve from 0 to last determination time) being 12.0% of that in conventional rats . Subsequently, a considerable amount (55.1 +/- 6.2%) of baicalin was recovered from the gastrointestinal tract even 4 h after administration . When baicalein was orally administered to conventional rats, however, baicalin appeared rapidly in their plasma at an AUC0-lim value similar to that obtained after oral administration of baicalin, despite the absence of baicalein in plasma . When intestinal absorption was evaluated by the rat jejunal loop method, baicalein was absorbed readily, but only traces of baicalin were absorbed . Moreover, in conventional rats a small amount (13.4 +/- 3.1%) of baicalin and an appreciable amount (21.9 +/- 3.4%) of baicalein were recovered from the gastrointestinal tract even 4 h after oral administration of baicalin, but only a small amount (3.93 +/- 1.43%) of baicalein was detected in the intestinal tract 1 h after administration of baicalein . Baicalin was transformed to baicalein readily by the rat gastric and caecal contents . When baicalin was administered orally to conventional rats, an appreciable amount of baicalein was recovered in their gastrointestinal tracts . Moreover, baicalein was efficiently conjugated to baicalin in rat intestinal and hepatic microsomes . These results indicate that baicalin itself is poorly absorbed from the rat gut, but is hydrolysed to baicalein by intestinal bacteria and then restored to its original form from the absorbed baicalein in the body. Genes Immun, 2000 Jun, 1(5), 308 - 15 Targeting the mucosa: genetically engineered vaccines and mucosal immune responses; Stevceva L et al.; The discovery that inoculation of DNA leads to strong and long lasting immune responses generated enthusiasm to assess the efficacy of various genetically engineered vaccines against mucosally acquired infections . Various techniques have been used to generate the most suitable DNA vaccines, ranging from immunization with naked DNA to utilizing genetically engineered recombinant viruses and bacteria to deliver the DNA . Different DNA vaccine modalities and mucosal immune responses to them have been discussed . It has been shown that even though intramuscular and intradermal immunization with these vaccines generates strong systemic responses, mucosal responses are not induced . It has been proposed that the site of immunization determines mucosal immune responses and that primed lymphocytes preferentially accumulate at sites where they have been induced thus generating the strongest cellular and antibody responses at the site of vaccination . The impact of the site of induction on mucosal immune responses to vaccines is discussed . It is possible to enhance desired vaccine effects in the mucosa and to modify the undesirable side effects . Cytokines such as IL-2, IL-12, IL-15 and IL-18 have been used to enhance CTL activity while IL-5, IL-6 and the chemokine MIP-1 alpha have shown the capacity to increase IgA responses to vaccines. Verh K Acad Geneeskd Belg, 2000, 62(6), 501 - 63 {Intra- and intercellular Ca(2+)-signal transduction}; Himpens B et al.; Calcium is one of the most universal signal-transduction elements in a large variety of cells ranging from bacteria to specialized neurons . Ca2+ acts as a second messenger controlling such processes as secretion, cell differentiation or signal transmission . In order to be able to execute their specific functions and to react in a coordinated way to stimuli, multicellular organs need a precise orchestration of cellular functions . For this purpose cells have developed different forms of intercellular communication (IC) . In this study we investigated a number of mechanisms of intracellular propagation and IC using experiments with fluorescent Ca(2+)-indicators, confocal microscopy and digital imaging techniques . In ROS 17/2.8 osteoblasts, retinal pigment epithelial cells (RPE) and CPAE endothelial cells, a small mechanical deformation of the plasma membrane results in a transient increase of free cytoplasmic Ca2+ concentration ({Ca2+}i) . This Ca(2+)-rise starts at the site of stimulation and propagates concentrically to neighboring cell layers . The intracellular Ca(2+)-wave in RPE and ROS cells is caused by Ca(2+)-influx followed by Ca(2+)-release from the intracellular stores and by intercellular propagation of the Ca(2+)-wave . The {Ca2+}i-transient upon mechanical stimulation of LLC-PK1 epithelial cells, C6 glioma cells and MLO-Y4 osteocytes was limited and/or variable . In CPAE cells only the intracellular release is important for evoking the Ca(2+)-transient, and is followed by IC . IC can occur via gap junctions (GJ) consisting of membrane-spanning proteins, connexins (Cx) . It was demonstrated that IC and GJ in RPE and ROS cells can be reversibly blocked by gap-junction inhibitors such as heptanol or halothane . We demonstrated important differences in modulation of gap junctional communication between these cell types . While in RPE cells stimulation of PKC activity was able to inhibit IC, this was not the case in ROS cells . We screened LE-RPE cDNA via PCR using specific primers for different connexins and found no effect of high glucose solutions, which cause decreased intercellular communication, on the Cx-isoforms expressed . Cx43 is the only Cx-isoform present at the protein level for which Western blot analysis revealed the presence of different forms corresponding to different phosphorylated states . Increased phosphorylation of Cx43 was only seen after direct PKC activation by PMA, but not by indirect PKC activation by high glucose levels . The decreased communication by high glucose concentrations was however associated by a decreased expression of cellular Cx43 to about 3/4 of the level in control conditions . High glucose concentrations therefore decrease Cx43 at the protein level via a PKC effect that appears to be independent of the direct activation of PKC by phorbolesters . Mechanical stimulation did not evoke intercellular Ca(2+)-waves in LLC-PK1 epithelial cells, C6 glioma cells and MLO-Y4 osteocytes . In CPAE-endothelial cells, the contribution of gap junctions to IC following mechanical stimulation is negligible, and modulation of gap junctions via phosphorylation or high glucose solutions is absent . Perfusion experiments and pharmacological studies demonstrated that IC following mechanical stimulation of these cells occurs via release of an extracellular mediator . Our experiments provide strong evidence in favor of purinergic agonists as mediators, such as ATP but mainly ADP . In conclusion we can say that cells contain a wide spectrum of mechanisms for intra- and intercellular communication, and that widely different mechanisms can evoke the same phenomenon of intra- and intercellular Ca(2+)-waves. Biotechniques, 2001 Jan, 30(1), 150 - 7 Quantitative detection of Chlamydia spp . by fluorescent PCR in the LightCycler; Huang J et al.; Quantitative detection of intracellular bacteria of the genus Chlamydia by the standard cell culture method is cumbersome and operator dependent . As an alternative, we adapted hot-start PCR to the glass capillary quantitative PCR format of the LightCycler . The optimized PCR was consistently more efficient than commercially available pre-assembled PCRs . Detection by quantitative PCR of as few as single copies of DNA of Chlamydia spp . was accomplished by SYBR Green fluorescence of the dsDNA product and by fluorescence resonance energy transfer (FRET) hybridization probes . The PCRs were 15-fold more sensitive than the cell culture quantitative assay of C . psittaci B577 infectious stock . The number of chlamydial genomes detected by C . psittaci B577 FRET PCR correlated well with cell culture determination of inclusion forming units (IFUs) (r = 0.96, P < 0.0008) . When infected tissue samples were analyzed by cell culture and PCR, the correlation coefficient between IFUs and chlamydial genomes was higher with C . psittaci B577 FRET PCR (r = 0.90, P < 0.0004) than with Chlamydia omp1 SYBR Green PCR (r = 0.85, P < 0.002). Mikrobiologiia, 2000 Nov-Dec, 69(6), 764 - 9 {Facultative and obligate aerobic methylobacteria synthesize cytokinins}; Ivanova EG et al.; The presence and expression of genes controlling the synthesis and secretion of cytokinins by the pink-pigmented facultative methylotroph Methylobacterium mesophilicum VKM B-2143 with the serine pathway and nonpigmented obligate methylotroph Methylovorus mays VKM B-2221 with the ribulose monophosphate pathway of C1 metabolism were shown using the polymerase chain reaction (PCR) and reverse transcription-PCR methods . The presence of the corresponding mRNA in M . mesophilicum cells grown on methanol or succinate suggests that the expression of these genes is constitutive . The cytokinin activity of culture liquid and its fractions was determined by a biotest with Amarantus caudatus L . seedlings . Using enzyme-linked immunosorbent analysis, we detected zeatin (riboside) in the culture liquid of both bacteria studied . The data obtained show that the aerobic methylobacteria are phytosymbionts that are able to utilize the single- and polycarbon compounds secreted by symbiotic plants and to synthesize cytokinins. Genome, 2000 Dec, 43(6), 939 - 44 Automictic parthenogenesis in the parasitoid Venturia canescens (Hymenoptera: Ichneumonidae) revisited; Beukeboom LW et al.; Both arrhenotokous and thelytokous reproduction are known to occur in the parasitoid wasp Venturia canescens . The cytological mechanism of thelytoky was previously reported to involve the formation of a restitution metaphase after the reduction division, but the exact nature of the subsequent divisions, whether reductional or equational, remained unclear . We reinvestigated the cytological mechanisms in a thelytokous strain collected in France . Our observations confirm previous results, but an equational and not a reduction division was observed after restitution . This type of reproduction can be classified as central fusion automictic parthenogenesis . In two arrhenotokous strains the normal pattern of oogenesis and syngamy of Hymenoptera was observed . In addition, we used PCR amplification to show that thelytoky in V . canescens is not caused by Wolbachia bacteria . The results are discussed in relation to maintenance of heterozygosity and female sex. Mol Plant Microbe Interact, 2001 Jan, 14(1), 93 - 7 Azorhizobium caulinodans ORS571 colonizes the xylem of Arabidopsis thaliana; Stone PJ et al.; Improved conditions were used for the aseptic growth of Arabidopsis thaliana to investigate whether xylem colonization of A . thaliana by Azorhizobium caulinodans ORS571 might occur . When seedlings were inoculated with ORS571 (pXLGD4) tagged with the lacZ reporter gene, nearly all of the plants showed blue regions of ORS571 colonization at lateral root cracks (LRC) . The flavonoids naringenin and liquiritigenin significantly stimulated colonization of LRC by ORS571 . Blue bands of ORS571 (pXLGD4) bacteria were observed histochemically in the xylem of intact roots of inoculated plants . Detailed microscopic analysis of sections of primary and lateral roots from inoculated A . thaliana confirmed xylem colonization . Xylem colonization also occurred with an ORS571 nodC mutant deficient in nodulation factors . There was no significant difference in the percentage of plants with xylem colonization or in the mean length of xylem colonized per plant between plants inoculated with either ORS571 (pXLGD4) or ORS571::nodC (pXLGD4), with or without naringenin. Ann N Y Acad Sci, 2000, 916, 172 - 8 Biocontrol of ticks; Samish M; The increasing resistance of arthropodes to pesticides, their high price, and the growing public demand for safer food and a cleaner environment are obliging animal growers to minimize the use of pesticides by introducing alternative means for tick control . The development of a biological tick control method has been neglected as compared to the control of plant pests or dipterous insects harmful to men and animals . There are abundant observations, but only a few studies have as yet been conducted on pathogens, parasitoides, and predators of ticks . A first attempt at tick biocontrol was made with the introduction of tick-parasitic wasps from France to the USA and Russia . During the past decade, interest in developing antitick biocontrol agents such as birds (Brazil, Kenya, and Zimbabwe), parasitoides (Kenya and USA), entomopathogenic nematodes (Egypt, Israel, Guadeloupe, and USA), entomopathogenic fungi (Brazil, Cuba, Israel, Kenya, and USA), and bacteria (Brazil) has gained momentum . The reintroduction of oxpecker birds in some areas of Zimbabwe remains up to now the only known successful attempt at tick biocontrol. Biosci Biotechnol Biochem, 2000 Nov, 64(11), 2412 - 9 Gene cloning, purification, and characterization of two cyanobacterial NifS homologs driving iron-sulfur cluster formation; Kato S et al.; Iron-sulfur proteins are essential in the photosynthetic system and many other biological processes . We have isolated and characterized enzymes driving the formation of iron-sulfur clusters from Synechocystis sp . PCC6803 . Two genes (slr0387 and sll0704), showing similarity to nifS of Azotobacter vinelandii, were cloned, and their gene products (SsCsdl and SsCsd2) were purified . They catalyzed the desulfuration of L-cysteine . Reconstitution of a {2Fe-2S} cluster of cyanobacterial ferredoxin proceeded much faster in the presence of L-cysteine and either of these enzymes than when using sodium sulfide . These results suggest that SsCsdl and SsCsd2 facilitate the iron-sulfur cluster assembly by producing inorganic sulfur from L-cysteine . Synechocystis sp . PCC6803 has no gene coding for a protein with similarity to the N-terminal domain of NifU of A . vinelandii, which is believed to cooperate with NifS to assemble iron-sulfur clusters . Thus, the cluster formation in the cyanobacterium probably proceeds through a mechanism that is different from that in A . vinelandii. Eur J Gastroenterol Hepatol, 2000 Dec, 12(12), 1267 - 73 Iron influences the expression of Helicobacter pylori outer membrane vesicle-associated virulence factors; Keenan JI et al.; BACKGROUND: Helicobacter pylori shed outer membrane vesicles (OMV) in vitro and in vivo . These OMV, which contain active VacA, provide a potential vehicle for the delivery of H . pylori virulence factors to the gastric mucosa . OBJECTIVE: To assess the influence of environmental iron levels on H . pylori OMV VacA and protease expression in vitro . METHODS: Three well-characterized H . pylori type-strains were grown for 72 h under normal (Brucella broth, 5% fetal calf serum) and iron-limiting (Brucella broth, 5% fetal calf serum, 50 micromol/l deferoxamine) conditions . Following harvesting by differential centrifugation, the ratio of whole cells to OMV was determined . OMV VacA levels in response to iron availability were determined by ELISA and immunolabelling of washed bacteria . Protease activity was detected by zymography of OMV in the presence and absence of enzyme inhibitors and activators . HEp-2 cells were used to assay for OMV-associated cytopathogenic toxins . RESULTS: Decreased iron availability, which limited bacterial growth but not OMV release, also influenced the expression of OMV-associated virulence factors . VacA levels were reduced, whereas two new proteolytic enzymes were expressed on these OMV . When an iron salt was added to counteract the effect of the deferoxamine, VacA levels were restored in the outer membrane and the proteolytic activity disappeared . CONCLUSIONS: These results suggest that OMV release by H . pylori is influenced by environmental iron levels, and that the qualitative changes that occur in outer membrane composition may contribute to the clinical patterns of H . pylori-associated disease. Theriogenology, 2000 Nov 1, 54(8), 1259 - 68 A novel approach for in vitro production of bovine embryos: use of the Oxoid atmosphere generating system; Avery B et al.; The importance of the incubator type is often overlooked when protocols for in vitro production of embryos are evaluated . In this study the ability of a standard CO2 Heraeus incubator and the Oxoid CO2Gen atmosphere-generating system to support bovine in vitro oocyte maturation, fertilization and embryo development is described for the first time . The Oxoid CO2Gen gas generating system, originally designed for the growth of bacteria, is based on the chemical reaction of ascorbic acid and air . When the sachet with ascorbic acid is placed in the confined volume of the airtight AnaeroJar, an atmosphere of 6% CO2 in 15% O2 is created, which is comparable to the 5% CO2 and 20% O2 used for standard in vitro production of bovine embryos . In the first set of experiments oocyte in vitro maturation (IVM), fertilization (IVF) and embryo culture (IVC) were allocated to one or the other of the culture systems . In the second set of experiments IVM and IVF took place in the Heraeus incubator, while IVC was allocated either to the Heraeus or to the AnaeroJar . During experiments the AnaeroJar was placed in the Heraeus incubator to ensure identical incubation temperatures of 38.8 degrees C . A standard protocol was used for production of embryos: 23 h of IVM in TCM-199, 20 h of IVF with frozen-thawed washed spermatozoa in TALP medium and 7 days of IVC (8 days after insemination) in B2 medium with bovine oviduct epithelial cells . In the first set of experiments, based on a total of 766 inseminated oocytes, the Day 8 blastocyst rates were the same in the Heraeus incubator and the AnaeroJar: 30% vs . 30% with oviduct cell coculture, and 21% vs . 18% without coculture . In the second set of experiments, based on 1963 inseminated oocytes, the average blastocyst rates were 27% vs . 32% from the Heraeus incubator and the AnaeroJar . In 2 of 6 replicates blastocyst rates were lower in the Heraeus incubator than in the jar; in the remaining replicates they were alike . No differences were noted in blastocyst kinetics or morphology . In conclusion, the Oxoid gas generating system seems to be a cheap, convenient and stable alternative to expensive CO2 incubators, not only for the growth of bacteria, but also for in vitro production of bovine embryos. Res Microbiol, 2000 Dec, 151(10), 831 - 6 Determination of the rpoB gene sequences of Bartonella henselae and Bartonella quintana for phylogenic analysis; Renesto P et al.; Using the Genome Walker procedure, which allows PCR amplification of genomic DNA using a single gene-specific primer and direct automated sequencing methodology, we obtained the nucleotide sequence of the RNA polymerase beta subunit (rpoB) from Bartonella henselae and Bartonella quintana . A phylogenetic tree constructed from these data and other rpoB sequences available in GenBank is, in part, consistent with those previously derived from 16S rRNA gene sequences and confirms the position of Bartonella within the alpha subdivision of Proteobacteria . In fact, this analysis showed that rpoB data are similar to 16S rRNA data for the alpha, beta and gamma subdivisions of Proteobacteria . In contrast, concerning other bacteria included in our study, the topologies of phylogenetic trees were different . Based on the bootstrap values derived from rpoB phylogenic analysis, we believe that this molecule should contribute to better understanding the evolutionary process. Trans Am Ophthalmol Soc, 2000, 98, 183 - 93; discussion 193-4 A comparative clinicopathologic study of endogenous mycotic endophthalmitis: variations in clinical and histopathologic changes in candidiasis compared to aspergillosis; Rao NA et al.; PURPOSE: Endophthalmitis caused by endogenous Candida and Aspergillus species has emerged as a visually threatening complication in patients with immune deficiency of various causes . Twenty-five patients who underwent enucleation, 13 with endogenous Aspergillus endophthalmitis and 12 with endogenous Candida intraocular infections, were evaluated . Both clinical features and intraocular spread of the fungi were studied to determine which clinical and/or histopathologic features could help distinguish aspergillosis from Candida infections . METHODS: Clinical information was sought from each case to determine whether there was any underlying systemic condition and to delineate the characteristic clinical features seen at initial presentation . The results of vitreous and other tissue cultures for bacteria and fungi were evaluated . Patients with AIDS were excluded . The enucleated globes were processed for histopathologic analysis to detect location of the fungal elements, inflammatory response, and vascular invasion by the fungi . RESULTS: With respect to the various predisposing systemic conditions, Candida species endophthalmitis was noted in patients with a history of gastrointestinal surgery, hyperalimentation, or diabetes mellitus, whereas aspergillosis was present in patients who had undergone organ transplantation or cardiac surgery . The vitreous was the primary focus of infection for Candida, whereas subretinal or sub-retinal pigment epithelium infection was noted in eyes with aspergillosis . Retinal and choroidal vessel wall invasion by fungal elements was noted in cases of aspergillosis but not in cases with candidiasis . The high rate of cerebral and cardiac infection in patients with Aspergillus endophthalmitis was not seen in those with Candida infection . CONCLUSIONS: The present study indicates that unlike Candida endophthalmitis, aspergillosis is seen in organ transplant or cardiac surgery patients, and its initial clinical presentation includes extensive areas of deep retinitis/choroiditis . Contrary to the findings in Candida endophthalmitis, vitreous biopsy may not yield positive results in aspergillosis . Aspergillus endophthalmitis is usually associated with a high rate of mortality caused by cerebral and cardiac complications. Rev Sci Tech, 2000 Apr, 19(1), 310 - 7 Public health implications of emerging zoonoses; Meslin FX et al.; Many new, emerging and re-emerging diseases of humans are caused by pathogens which originate from animals or products of animal origin . A wide variety of animal species, both domestic and wild, act as reservoirs for these pathogens, which may be viruses, bacteria or parasites . Given the extensive distribution of the animal species affected, the effective surveillance, prevention and control of zoonotic diseases pose a significant challenge . The authors describe the direct and indirect implications for public health of emerging zoonoses . Direct implications are defined as the consequences for human health in terms of morbidity and mortality . Indirect implications are defined as the effect of the influence of emerging zoonotic disease on two groups of people, namely: health professionals and the general public . Professional assessment of the importance of these diseases influences public health practices and structures, the identification of themes for research and allocation of resources at both national and international levels . The perception of the general public regarding the risks involved considerably influences policy-making in the health field . Extensive outbreaks of zoonotic disease are not uncommon, especially as the disease is often not recognised as zoonotic at the outset and may spread undetected for some time . However, in many instances, the direct impact on health of these new, emerging or re-emerging zoonoses has been small compared to that of other infectious diseases affecting humans . To illustrate the tremendous indirect impact of emerging zoonotic diseases on public health policy and structures and on public perception of health risks, the authors provide a number of examples, including that of the Ebola virus, avian influenza, monkeypox and bovine spongiform encephalopathy . Recent epidemics of these diseases have served as a reminder of the existence of infectious diseases and of the capacity of these diseases to occur unexpectedly in new locations and animal species . The need for greater international co-operation, better local, regional and global networks for communicable disease surveillance and pandemic planning is also illustrated by these examples . These diseases have contributed to the definition of new paradigms, especially relating to food safety policies and more generally to the protection of public health . Finally, the examples described emphasise the importance of intersectorial collaboration for disease containment, and of independence of sectorial interests and transparency when managing certain health risks. Rev Sci Tech, 2000 Apr, 19(1), 121 - 35 Lyme disease; Gern L et al.; Lyme borreliosis, the most common vector-borne disease in the northern hemisphere, is caused by bacteria belonging to the Borrelia burgdorferi complex . The disease is multisystemic, affecting mainly the skin, nervous system, heart and joints . In Europe, the vector of the disease is the tick Ixodes ricinus, whereas in the United States of America, two primary tick vectors exist, namely: I . scapularis in the north-eastern and mid-western regions and I . pacificus on the west coast . Several species of small and medium-sized mammals and ground-feeding birds serve as reservoirs for the bacteria in endemic areas . The prognosis for patients with Lyme borreliosis is excellent, particularly when diagnosed and treated early in the course of infection . Prevention of Lyme borreliosis can be achieved using two approaches, either prevention of infection by immunisation, or prevention of tick bites through avoidance, personal protection and tick control. Orv Hetil, 2000 Dec 10, 141(50), 2695 - 700 {Effect of Helicobacter pylori infection and eradication on proliferative kinetics of the gastric mucosa}; Unger Z et al.; Helicobacter pylori infection is associated with an increased cell proliferation activity, however the exact mechanisms have not been elucidated . Our aim was to study the effect of Helicobacter pylori infection on normal gastric epithelia, gastritis, intestinal metaplasia and carcinoma by the expression of proliferating cell nuclear antigen and nucleolus organizer regions . Antral biopsies were taken from 121 patients (61 women, 60 men; mean age 58.5 y.) . Sections were scored for normal epithelia (n = 15), gastritis without intestinal metaplasia (n = 74), gastritis with intestinal metaplasia (n = 24) and gastric carcinoma (n = 8) . 52 patients had H . pylori positive gastritis, and success of eradication therapy was controlled in 34 cases . To characterize cell proliferation immunohistochemistry (PCNA) and histochemistry methods (AgNOR) were used . Results of PCNA and AgNOR significantly correlated except of that in the intestinal metaplasia group . PCNA LI and AgNOR counts were not significant higher in H . pylori positive compared to the H . pylori negative gastritis . Presence of H . pylori caused higher proliferation rate in intestinal metaplasia group measured by PCNA . In the group of intestinal metaplasia the proliferation activity decreased to the activity of the normal epithelia after the successful eradication, but remained high if eradication therapy was failed . Our results suggest, that H . pylori infection plays only as a co-factor in gastric carcinogenesis . Results were controversial in the intestinal metaplasia group, that can be explained by the heterogeneity of the bacteria. Zhonghua Kou Qiang Yi Xue Za Zhi, 1997 Nov, 32(6), 347 - 9 {Effects of sodium doecyl sulfate on the artificial dental plaque in chemostat}; Wei G et al.; Sodium doecyl sulfate (SDS) is widely used as a detergent in dentifrices . It has been shown to interfere with the protein adsorption to hydroxyapatite (HA), and inhibit acquired pellicle formation . The aim of the present study was to examine the effects of SDS on the artificial dental plaque in chemostat . The amount of the 3H-labelled bacteria adhered on the enamel fragment surface was determined with scintillometer . The artificial dental plaque was observed under the scanning electron microscope . The results showed that enamel fragments treated with SDS adsorbed less bacteria than untreated ones, and had no plague formed . It suggested that SDS can inhibit the bacterial adherence on enamel surface and thus reduce dental plaque formation. Zhongguo Yi Liao Qi Xie Za Zhi, 1997 Nov, 21(6), 337 - 8 {Development of gas-liquid exchanger for complex retina pare operation}; Wang W et al.; A gas-liquid exchanger apparatus was developed for the complex operation of the retinal detachment . The bacteria-free gas can be obtained by using this apparatus . The pressure of the gas is successively adjustable, from 0 to 100 mmHg . The apparatus is very suitable for exchanging gas for liquid in the retinal surgery and raises the effect of the operation. Lakartidningen, 2000 Dec 13, 97(50), 5910 - 3 {When is H pylori a cause of duoenal ulcer? Hypersecretion of gastric acid, active duodenitis and reduced bicarbonate secretion are links in the chain}; Olbe L et al.; Helicobacter pylori infection engaging mainly the gastric antrum causes hypersecretion of gastric acid . The increased duodenal acid load gives rise to islands of gastric mucosa in the proximal duodenum . As these bacteria thrive only on gastric mucosa it presents an opportunity for Helicobacter pylori to colonize the duodenum . A much higher density of virulent Helicobacter pylori has been found in the duodenum of duodenal ulcer patients in comparison to infected subjects without duodenal ulcer . The high density of virulent Helicobacter pylori in the proximal duodenum results in a strong inflammatory reaction with active duodenitis and impaired bicarbonate secretion . These characteristics of duodenal ulcer patients, together with the acid hypersecretion, seem to be the key factors in evoking a duodenal ulcer. Nippon Rinsho, 2000 Dec, 58(12), 2434 - 8 {Phytoestrogens}; Kinjo J; Epidemiological studies revealed that foodstuffs, in particular, soy foods containing isoflavonoid phytoestrogens may reduce the risk of some hormone-dependent disease such as not only postmenopausal symptoms but also certain(breast, prostate and colon) cancers and cardiovascular disease . This review introduces the metabolism of soybean isoflavonoids by human intestinal bacteria and the binding and gene-expression activity of the metabolites towards the human estrogen receptor(hER) alpha and beta . The dietary isoflavones(daidzin and genistin) in soybean were metabolized to equol and dihydrogenistein via daidzein and genistein, respectively . The metabolites bind more strongly to hER beta than hER alpha . The binding affinity of genistein is comparable that of 17 beta-estradiol . Equol induces transcription most strongly both with hER beta and hER alpha. Rinsho Shinkeigaku, 2000 Jul, 40(7), 707 - 11 {Cerebral embolism in systemic lupus erythematosus with Libman-Sacks endocarditis: a case report}; Kasuya J et al.; We presented a patient of cerebral embolism caused by Libman-Sacks endocarditis with systemic lupus erythematosus (SLE) . This 35-year-old housewife with SLE suffered from abrupt visual disturbance in December 1998 . Angiography revealed the occlusion of her right posterior cerebral artery . Transesophageal echocardiography showed the mitral regurgitation and hyperplasia of the anterior mitral valve leaflet without vegetation . In April 1999, she again suffered from sudden onset of transient left hemiparesis and dysphasia . Angiographic findings were unchanged . Transesophageal echocardiographic examination detected vegetation on the anterior mitral valve leaflet and aggravation of the mitral regurgitation . Laboratory examination revealed inactivity of SLE . No bacteria was recovered from repeated blood cultures . We diagnosed that Libman-Sacks vegetation caused cerebral embolism. Urologiia, 2000 Mar-Apr, (2), 24 - 5 {Express method for evaluating the efficiency of bladder droplet irrigation}; Davidov MI; The catalase test is proposed for objective and rapid evaluation of the efficiency of droplet irrigation of the bladder after operations on the prostate, bladder, and urethra . Three milliliters of irrigation fluid is collected from the bladder drainage into a tube with 0.5 ml 3% hydrogen peroxide solution . If catalase is present in the lavage fluid (this enzyme is present in erythrocytes, leukocytes, and bacteria), hydrogen peroxide is degraded and oxygen is released . In a positive test gas bubbles and foam appear on the surface of the mixture . Three degrees of positive catalase test are defined . The rate and volume of perfusion are regulated with consideration for the test results; constant irrigation can be replaced by fractionation; negative results of the test allow discontinuation of irrigation . The rapid method was clinically tried in 20 patients with good results. Prehospital Disaster Med, 2000 Apr-Jun, 15(2), 9 - 13 Analysis of medical needs on day 7 after the tsunami disaster in Papua New Guinea; Asari Y et al.; INTRODUCTION: Because of great intervening distances, international medical relief activities in catastrophic, sudden-onset disasters often do not begin until days 5-7 after the precipitating event . The medical needs of those affected and what public health problems exist in the community in the week after the tsunami disaster in Papua New Guinea(PNG) were investigated . METHODS: The Japan Medical Team for Disaster Relief (JMTDR) conducted investigative hearings at the District Office responsible for the management of the disaster, the Care Center, and the Hospitals in Aitape, Vanimo, and Wewak in PNG . RESULTS: The numbers of in-patients in the Aitape, Vanimo, and Wewak Hospitals, and in the Care Center in Aitape were 291, > 300, 68, and 104, respectively . The exact number of people affected was unknown at the Aitape District Office . There was no lack of medical supplies and drugs in the hospital, but the Care Center in Aitape did not have sufficient quantities of antibiotics . No outbreak of communicable disease occurred, despite the presence of risk factors such as the dense concentration of affected people and the constant prevalence of malaria and diarrhea . The water at Wewak General Hospital contained chlorine and was suitable for drinking, but that elsewhere contained bacteria . CONCLUSIONS: On about the 7th day after the event, the available information still was incomplete, and it was a time to shift from initial emergency activities to specialized medical care . Although no outbreak of communicable disease actually occurred, there was much anxiety about it because of the risk factors present . For effective medical care at this stage, it is essential to conduct a survey of actual medical needs that also include epidemiological factors. Proc Natl Acad Sci U S A, 2001 Jan 16, 98(2), 670 - 5 Antigenic and genetic heterogeneity of Borrelia burgdorferi populations transmitted by ticks; Ohnishi J et al.; The genome of Borrelia burgdorferi encodes a large number of lipoproteins, many of which are expressed only at certain stages of the spirochete's life cycle . In the current study we describe the B . burgdorferi population structure with respect to the production of two lipoproteins {outer surface protein A (OspA) and outer surface protein C (OspC)} during transmission from the tick vector to the mammalian host . Before the blood meal, the bacteria in the tick were a homogeneous population that mainly produced OspA only . During the blood meal, the population became more heterogeneous; many bacteria produced both OspA and OspC, whereas others produced only a single Osp and a few produced neither Osp . From the heterogeneous spirochetal population in the gut, a subset depleted of OspA entered the salivary glands and stably infected the host at time points >53 hr into the blood meal . We also examined genetic heterogeneity at the B . burgdorferi vlsE locus before and during the blood meal . In unfed ticks, the vlsE locus was stable and one predominant and two minor alleles were detected . During the blood meal, multiple vlsE alleles were observed in the tick . Tick feeding may increase recombination at the vlsE locus or selectively amplify rare vlsE alleles present in unfed ticks . On the basis of our data we propose a model, which is different from the established model for B . burgdorferi transmission . Implicit in our model is the concept that tick transmission converts a homogeneous spirochete population into a heterogeneous population that is poised to infect the mammalian host. J Bacteriol, 2001 Feb, 183(3), 1069 - 77 Starchless mutants of Chlamydomonas reinhardtii lack the small subunit of a heterotetrameric ADP-glucose pyrophosphorylase; Zabawinski C et al.; ADP-glucose synthesis through ADP-glucose pyrophosphorylase defines the major rate-controlling step of storage polysaccharide synthesis in both bacteria and plants . We have isolated mutant strains defective in the STA6 locus of the monocellular green alga Chlamydomonas reinhardtii that fail to accumulate starch and lack ADP-glucose pyrophosphorylase activity . We show that this locus encodes a 514-amino-acid polypeptide corresponding to a mature 50-kDa protein with homology to vascular plant ADP-glucose pyrophosphorylase small-subunit sequences . This gene segregates independently from the previously characterized STA1 locus that encodes the large 53-kDa subunit of the same heterotetramer enzyme . Because STA1 locus mutants have retained an AGPase but exhibit lower sensitivity to 3-phosphoglyceric acid activation, we suggest that the small and large subunits of the enzyme define, respectively, the catalytic and regulatory subunits of AGPase in unicellular green algae . We provide preliminary evidence that both the small-subunit mRNA abundance and enzyme activity, and therefore also starch metabolism, may be controlled by the circadian clock. J Bacteriol, 2001 Feb, 183(3), 882 - 9 Ammonia switch-off of nitrogen fixation in the methanogenic archaeon Methanococcus maripaludis: mechanistic features and requirement for the novel GlnB homologues, NifI(1) and NifI(2); Kessler PS et al.; Ammonia switch-off is the immediate inactivation of nitrogen fixation that occurs when a superior nitrogen source is encountered . In certain bacteria switch-off occurs by reversible covalent ADP-ribosylation of the dinitrogenase reductase protein, NifH . Ammonia switch-off occurs in diazotrophic species of the methanogenic Archaea as well . We showed previously that in Methanococcus maripaludis switch-off requires at least one of two novel homologues of glnB, a family of genes whose products play a central role in nitrogen sensing and regulation in bacteria . The novel glnB homologues have recently been named nifI(1) and nifI(2) . Here we use in-frame deletions and genetic complementation analysis in M . maripaludis to show that the nifI(1) and nifI(2) genes are both required for switch-off . We could not detect ADP-ribosylation or any other covalent modification of dinitrogenase reductase during switch-off, suggesting that the mechanism differs from the well-studied bacterial system . Furthermore, switch-off did not affect nif gene transcription, nifH mRNA stability, or NifH protein stability . Nitrogenase activity resumed within a short time after ammonia was removed from a switched-off culture, suggesting that whatever the mechanism, it is reversible . We demonstrate the physiological importance of switch-off by showing that it allows growth to accelerate substantially when a diazotrophic culture is switched to ammonia. Gastroenterology, 2001 Jan, 120(1), 49 - 59 Regulated production of interferon-inducible T-cell chemoattractants by human intestinal epithelial cells; Dwinell MB et al.; BACKGROUND & AIMS: Human intestinal epithelial cells inducibly express neutrophil and monocyte chemoattractants, yet little is known about the regulated production of T-cell chemoattractants by the intestinal epithelium . IP-10, Mig, and I-TAC are 3 CXC chemokines that are known to act as CD4(+) T-cell chemoattractants . METHODS: We studied constitutive chemokine expression in human colon, and defined the regulated expression of these chemokines by reverse-transcription polymerase chain reaction, enzyme-linked immunosorbent assay, and immunohistology using cultured human intestinal epithelial cell lines and a novel adaptation of an in vivo human intestinal xenograft model . RESULTS: IP-10 and Mig were constitutively expressed by normal human colon epithelium, and their cognate receptor, CXCR3, was expressed by mucosal mononuclear cells . Interferon (IFN)-gamma stimulation increased mRNA expression and the polarized basolateral secretion of these chemokines by human colon epithelial cell lines; infection with enteroinvasive bacteria, or stimulation with the proinflammatory cytokines tumor necrosis factor alpha and interleukin 1alpha, strongly potentiated IFN-gamma-induced epithelial cell IP-10, Mig, and I-TAC production . Epithelial cell mRNA and protein expression of IP-10, Mig, and I-TAC were rapidly up-regulated in human intestinal xenografts in response to stimulation with IFN-gamma alone or in combination with IL-1 . CONCLUSIONS: The constitutive and regulated production of the IFN-gamma-inducible chemokines IP-10, Mig, and I-TAC by human intestinal epithelium, and the expression of their cognate receptor, CXCR3, by mucosal mononuclear cells, suggest that the intestinal epithelium can play a role in modulating physiologic and pathologic T cell-mediated mucosal inflammation. Traffic, 2000 Mar, 1(3), 235 - 47 Trafficking and release of mycobacterial lipids from infected macrophages; Beatty WL et al.; Analysis of infected macrophages revealed that lipid-containing moieties of the mycobacterial cell wall are actively trafficked out of the mycobacterial vacuole . To facilitate the analysis of vesicular trafficking from mycobacteria-containing phagosomes, surface-exposed carbohydrates were labeled with hydrazide-tagged markers . The distribution of labeled carbohydrate/lipid moieties and subsequent interaction with cellular compartments were analyzed by immunoelectron microscopy and by fluorescence microscopy of live cells . The released mycobacterial constituents were associated with several intracellular organelles and were enriched strikingly in tubular endocytic compartments . Subcellular fractionation of infected macrophages by density gradient electrophoresis showed temporal movement of labeled bacterial constituents through early and late endosomes . Thin layer chromatography analysis of these subcellular fractions confirmed their lipid nature and revealed five dominant bacteria-derived species . These mycobacterial lipids were also found in extracellular vesicles isolated from the medium and could be observed in un-infected 'bystander' cells . Their transfer to bystander cells could expand the bacteria's sphere of influence beyond the immediate confines of the host cell. Traffic, 2000 Feb, 1(2), 100 - 6 Cell invasion by un-palatable parasites; Sibley LD et al.; While some intracellular pathogens invade and replicate exclusively in phagocytic host cells, others have evolved mechanisms to stimulate their uptake by cells not equipped with a well-developed phagocytic machinery . A common mechanism utilized by bacteria involves the induction of macropinocytosis, or of other F-actin-driven processes which result in engulfment of the pathogen through formation of a plasma membrane-derived vacuole . Interestingly, this type of "induced phagocytosis" mechanism does not appear to be utilized by protozoan parasites, which are significantly larger than bacteria in size (about 5-10 microns in average length) . Intracellular protozoa either restrict themselves to infecting "professional" phagocytes (one example is the trypanosomatid Leishmania), or utilize highly unusual mechanisms for gaining access to the intracellular environment . Here we discuss what has been revealed in recent years about the remarkable cell invasion strategies of two highly successful intracellular parasites: Toxoplasma gondii and Trypanosoma cruzi . Toxoplasma utilizes a distinct form of actin/myosin-dependent gliding motility to propel itself into mammalian cells, while T . cruzi invades by subverting a Ca(2+)-regulated lysosomal exocytic pathway. Environ Microbiol, 1999 Oct, 1(5), 431 - 8 Host specificity in the Richelia-diatom symbiosis revealed by hetR gene sequence analysis; Janson S et al.; The filamentous heterocyst-forming cyanobacterium Richelia intracellularis forms associations with diatoms and is very abundant in tropical and subtropical seas . The genus Richelia contains only one species, R . intracellularis Schmidt, although it forms associations with several diatom genera and has considerable variation in size and morphology . The genetic diversity, and possible host specificity, within the genus Richelia is unknown . Using primers against hetR, a gene unique for filamentous cyanobacteria, specific polymerase chain reaction (PCR) products were obtained from natural populations of R . intracellularis filaments associated with three diatom genera . Phylogenetic analyses of these sequences showed that they were all in the same clade . This clade contained only the R . intracellularis sequences . The genetic affiliation of hetR sequences of R . intracellularis to those of other heterocystous cyanobacteria strongly suggests that it was not closely related to endosymbiotic Nostoc spp . hetR sequences . Sequences from R . intracellularis-Hemiaulus membranaceus sampled in the Atlantic and Pacific Oceans were almost identical, demonstrating that the genetic relatedness was not dependent on geographical location . All sequences displayed a deep divergence between symbionts from different genera and a high degree of host specificity. Cell Microbiol, 2001 Jan, 3(1), 21 - 31 Interaction of Helicobacter pylori with professional phagocytes: role of the cag pathogenicity island and translocation, phosphorylation and processing of CagA; Odenbreit S et al.; Chronic infection of the human gastric mucosa with Helicobacter pylori is a major cause of gastroduodenal pathologies, including peptic ulcerations, mucosa-associated lymphoid tissue (MALT) lymphoma and adenocarcinoma . Helicobacter pylori strains carrying the cag pathogenicity island, which encodes an active type IV protein secretion system (cag+ or type I strains), are preferentially associated with strong gastric inflammation and severe disease . We show here that cag+ H . pylori strains use the type IV secretion system to inject the bacterial protein CagA into various types of professional phagocytes, including human polymorphonuclear leucocytes (PMNs) and the human and murine macrophage cell lines THP-1 and J774A.1 CagA is rapidly tyrosine phosphorylated and proteolytically processed to generate a stable 35-45 kDa C-terminally tyrosine-phosphorylated protein fragment . H . pylori was efficiently ingested by the different types of phagocytic cells . A chromosomal deletion of the complete pathogenicity island had no significant effect on the rate of ingestion . Furthermore, the survival rate of H . pylori in the phagosome was unchanged between the wild type and a deletion mutant lacking the type IV secretion system . Thus, the type IV secretion system seems to be involved neither in active phagocytosis resistance nor in prolonged survival of the bacteria in phagocytic cells. Cell Microbiol, 2000 Dec, 2(6), 627 - 37 Host cell-derived sphingolipids a