J Biol Chem, 2001 Jun 15, 276(24), 21311 - 6 Epub 2001 Apr 03. Evidence for direct interaction between enzyme I(Ntr) and aspartokinase to regulate bacterial oligopeptide transport; King ND et al.; Bradyrhizobium japonicum transports oligopeptides and the heme precursor delta-aminolevulinic acid (ALA) by a common mechanism . Two Tn5-induced mutants disrupted in the lysC and ptsP genes were identified based on the inability to use prolyl-glycyl-glycine as a proline source and were defective in {(14)C}ALA uptake activity . lysC and ptsP were shown to be proximal genes in the B . japonicum genome . However, RNase protection and in trans complementation analysis showed that lysC and ptsP are transcribed separately, and that both genes are involved in oligopeptide transport . Aspartokinase, encoded by lysC, catalyzes the phosphorylation of aspartate for synthesis of three amino acids, but the lysC strain is not an amino acid auxotroph . The ptsP gene encodes Enzyme I(Ntr) (EI(Ntr)), a paralogue of Enzyme I of the phosphoenolpyruvate:sugar phosphotransferase (PTS) system . In vitro pull-down experiments indicated that purified recombinant aspartokinase and EI(Ntr) interact directly with each other . Expression of ptsP in trans from a multicopy plasmid complemented the lysC mutant, suggesting that aspartokinase normally affects Enzyme I(Ntr) in a manner that can be compensated for by increasing the copy number of the ptsP gene . ATP was not a phosphoryl donor to purified EI(Ntr), but it was phosphorylated by ATP in the presence of cell extracts . This phosphorylation was inhibited in the presence of aspartokinase . The findings demonstrate a role for a PTS protein in the transport of a non-sugar solute and suggest an unusual regulatory function for aspartokinase in regulating the phosphorylation state of EI(Ntr). Placenta, 2001 Apr, 22(4), 360 - 71 Study on risk factors for transplacental viral infections; effect of bacterial factors and double viral infections on virus replication in placenta and amniotic membranes; Jatczak B et al.; Among risk factors for vertical transmission of HIV there are listed concomitant viral and bacterial infections . Therefore the influence on the viruses replication in human placenta and amniotic membrane cultures of double viral infection with two unrelated viruses - encephalomyocarditis (EMCV) and vesicular stomatitis virus (VSV) - was studied and compared with the replication of the viruses in single virus infection (EMCV or VSV) in the same organ cultures . Additionally effect of bacterial factors - lipopolysaccharide (LPS) Escherichia coli and sonicated Treponema pallidum antigens (Tpa) - on VSV replication in the same culture system was studied and compared with VSV replication in untreated explants . Two effects were observed in double-virus infected cultures and also in bacterial factors treated cultures: inhibition and stimulation of virus replication . The kind of effect in the both cases was dependent on the presence or absence of innate antiviral immunity . In virus-sensitive organs double infected or treated with LPS or Tpa, inhibition of virus titer (2-5 log TCID(50)/ml) was observed . In the organs expressing the innate immunity, stimulation (1-4 log TCID(50)/ml) of virus replication was noticed . Contribution of endogenous TNFalpha in both reactions (stimulation and inhibition) was confirmed using antibodies against the TNF . Int J Infect Dis, 2001, 5(1), 9 - 18 Effect of surfactant and specific antibody on bacterial proliferation and lung function in experimental pneumococcal pneumonia; Gan X et al.; OBJECTIVE: To investigate the effect of surfactant and specific antibody on bacterial proliferation in experimental pneumococcal pneumonia . METHODS: Near-term newborn rabbits received a standard dose (10(7)) of type 3 pneumococci via the airways . Control animals were sacrificed 1 minute later . Other animals were ventilated for 5 hours and treated via the tracheal cannula with surfactant (Curosurf 200 mg/kg), a mixture of surfactant and a polyclonal antipneumococcal antibody, the antibody without surfactant, or saline . RESULTS: There was a significant bacterial proliferation in lung tissue in all animals ventilated for 5 hours . Bacterial growth, expressed as log10 colony forming units (CFU) per gram of lung tissue was less prominent in animals treated with a mixture of surfactant and specific antibody than in animals treated with antibody alone (median, 7.51, range, 6.80--7.70 vs . median, 7.92, range, 7.07--8.50; P < 0.05) . Dynamic lung-thorax compliance was improved with surfactant or surfactant plus antibody in comparison with saline or antibody alone . CONCLUSIONS: The data suggest that the suppressive effect of the antibody on bacterial proliferation becomes evident only when surfactant is administered together with the antibody. Eur J Neurosci, 2001 Mar, 13(6), 1155 - 65 Central monoamine and plasma corticosterone changes induced by a bacterial endotoxin: sensitization and cross-sensitization effects; Hayley S et al.; Low doses of lipopolysaccharide, tumour necrosis factor-alpha (TNF-alpha), interleukin-1 beta (IL-1 beta), or exposure to a stressor (restraint) increased plasma corticosterone levels . In animals pretreated with lipopolysaccharide, a marked sensitization of the corticosterone response was evident upon subsequent exposure to lipopolysaccharide, TNF-alpha, or restraint, 1 day later . As well, the sickness-inducing effects of lipopolysaccharide, TNF-alpha and IL-1 beta were markedly increased in mice pretreated with lipopolysaccharide . The sensitization effects were marked when the second treatment was administered 1 day after lipopolysaccharide administration, but not when a 28-day interval elapsed . In a second experiment, TNF-alpha influenced monoamine functioning in the paraventricular nucleus of the hypothalamus and within extrahypothalamic regions, including the central amygdala, locus coeruleus, prefrontal cortex . Moreover, serotonin activity within the central amygdala, as well as dopamine activity within the prefrontal cortex, were subject to a sensitization effect in animals pretreated with lipopolysaccharide 1 day earlier . Macrophage depletion by a suspension of clodronate liposomes attenuated the plasma corticosterone changes induced by TNF-alpha, but did not affect the sensitization . In contrast, the acute effects of TNF-alpha on central neurotransmitters were unaffected by the liposome suspension, but this treatment prevented the sensitization . These data may be relevant to clinical situations in which individuals exposed to bacterial infections may be rendered more susceptible to the behavioural and neurochemical effects of subsequently encountered stressors and immunological challenges. Eur J Neurosci, 2001 Mar, 13(6), 1101 - 6 Bacterial endotoxin sensitizes the immature brain to hypoxic--ischaemic injury; Eklind S et al.; Epidemiological studies show a markedly increased risk of cerebral palsy following the combined exposure of infection and birth asphyxia . However, the underlying mechanisms of this increased vulnerability remain unclear . We have examined the effects of a low dose of bacterial endotoxin on hypoxic--ischaemic injury in the immature brain of rats . Bacterial endotoxin (lipopolysaccharide 0.3 mg/kg) was administered to 7-day-old rats 4 h prior to unilateral hypoxia--ischaemia and the neurological outcome was determined 3 days later . Rectal temperature and cerebral blood flow was measured during the study and the expression of CD14 and toll-like receptor-4 mRNA in the brain was examined . We found that a low dose of endotoxin dramatically sensitizes the immature brain to injury and induces cerebral infarction in response to short periods of hypoxia--ischaemia that by themselves caused no or little injury . This effect could not be explained by a reduction in cerebral blood flow or hyperthermia . In association with the sensitization of injury we found an altered expression of CD14 mRNA and toll-like receptor-4 mRNA in the brain . These results suggest that the innate immune system may be involved in the vulnerability of the immature brain following the combination of infection and hypoxia--ischaemia. JPEN J Parenter Enteral Nutr, 2001 Mar-Apr, 25(2), 60 - 4 Liquid enteral diets induce bacterial translocation by increasing cecal flora without changing intestinal motility; Haskel Y et al.; The aim of this study was to determine the contribution of intestinal motility and cecal bacterial overgrowth to liquid diet-induced bacterial translocation (BT) . Three different commercially available liquid diets were offered to mice for 1 week . BT to the mesenteric lymph nodes (MLN), spleen, and liver were examined as well as cecal bacterial counts and populations, small bowel length and weight, and histopathologic changes in the ileal and jejunal mucosa . In addition, the effect of the various diets on intestinal motility was measured by the transit index of a charcoal mixture introduced into the stomach . The incidence of BT to the mesenteric lymph nodes was significantly and similarly increased (p < .05) in mice fed Vivonex (30%), Ensure (30%), and Osmolite (33%) compared with chow-fed controls (0%) . Compared with chow-fed controls, all three liquid diets were associated with the development of cecal bacterial overgrowth (p < .01) . There were no significant changes in the transit index for the three liquid diet groups compared with the chow-fed controls . BT to the MLN was induced by all three liquid diets tested, casting some doubts as to their role in preventing BT in clinical use . BT was associated with a statistically significant increase in cecal bacterial count but was not associated with gut motility changes in this model . In fact, no significant changes in intestinal motility were noted in all groups tested. Appl Environ Microbiol, 2001 Apr, 67(4), 1830 - 8 Rapid method of determining factors limiting bacterial growth in soil; Alden L et al.; A technique to determine which nutrients limit bacterial growth in soil was developed . The method was based on measuring the thymidine incorporation rate of bacteria after the addition of C, N, and P in different combinations to soil samples . First, the thymidine incorporation method was tested in two different soils: an agricultural soil and a forest humus soil . Carbon (as glucose) was found to be the limiting substance for bacterial growth in both of these soils . The effect of adding different amounts of nutrients was studied, and tests were performed to determine whether the additions affected the soil pH and subsequent bacterial activity . The incubation time required to detect bacterial growth after adding substrate to the soil was also evaluated . Second, the method was used in experiments in which three different size fractions of straw (1 to 2, 0.25 to 1, and <0.25 mm) were mixed into the agricultural soil in order to induce N limitation for bacterial growth . When the straw fraction was small enough (<0.25 mm), N became the limiting nutrient for bacterial growth after about 3 weeks . After the addition of the larger straw fractions (1 to 2 and 0.25 to 1 mm), the soil bacteria were C limited throughout the incubation period (10 weeks), although an increase in the thymidine incorporation rate after the addition of C and N together compared with adding them separately was seen in the sample containing the size fraction from 0.25 to 1 mm . Third, soils from high-pH, limestone-rich areas were examined . P limitation was observed in one of these soils, while tendencies toward P limitation were seen in some of the other soils. Appl Environ Microbiol, 2001 Apr, 67(4), 1775 - 82 Does the high nucleic acid content of individual bacterial cells allow us to discriminate between active cells and inactive cells in aquatic systems? Lebaron P, Servais P, Agogue H, Courties C, Joux F. The nucleic acid contents of individual bacterial cells as determined with three different nucleic acid-specific fluorescent dyes (SYBR I, SYBR II, and SYTO 13) and flow cytometry were compared for different seawater samples . Similar fluorescence patterns were observed, and bacteria with high apparent nucleic acid contents (HNA) could be discriminated from bacteria with low nucleic acid contents (LNA) . The best discrimination between HNA and LNA cells was found when cells were stained with SYBR II . Bacteria in different water samples collected from seven freshwater, brackish water, and seawater ecosystems were prelabeled with tritiated leucine and then stained with SYBR II . After labeling and staining, HNA, LNA, and total cells were sorted by flow cytometry, and the specific activity of each cellular category was determined from leucine incorporation rates . The HNA cells were responsible for most of the total bacterial production, and the specific activities of cells in the HNA population varied between samples by a factor of seven . We suggest that nucleic acid content alone can be a better indicator of the fraction of growing cells than total counts and that this approach should be combined with other fluorescent physiological probes to improve detection of the most active cells in aquatic systems. Appl Environ Microbiol, 2001 Apr, 67(4), 1565 - 74 Bacterial diversity and community structure in an aerated lagoon revealed by ribosomal intergenic spacer analyses and 16S ribosomal DNA sequencing; Yu Z et al.; We investigated the bacterial community structure in an aerated plug-flow lagoon treating pulp and paper mill effluent . For this investigation, we developed a composite method based on analyses of PCR amplicons containing the ribosomal intergenic spacer (RIS) and its flanking partial 16S rRNA gene . Community percent similarity was determined on the basis of RIS length polymorphism . A community succession was evident in the lagoon, indicated by a progressive community transition through seven sample locations . The most abrupt changes in community structure were associated with a temperature change from 39 to 35 degrees C and with increases in dissolved oxygen . The temporal differences in community structure, based on summer and winter samplings, were greater than the spatial differences during either season . Clone libraries of rDNA-RIS amplicons were constructed from each of three summer samples . Among 90 clones analyzed (30 clones from each sample), 56 phylotypes were distinguished by restriction fragment length polymorphism . Indices of phylotype richness, evenness, and diversity all increased in clone libraries from the beginning to the end of the lagoon . A representative clone of each phylotype was phylogenetically analyzed on the basis of its partial 16S rRNA gene sequence (ca . 450 bp) . Phylogenetic analysis confirmed the increase in diversity and further indicated increasing richness of bacterial divisions . Pioneers in the community spatial succession appeared to include thermotolerant, microaerophilic methanol-oxidizing bacteria related to the genus Methylobacillus, as well as thermotolerant, microaerophilic nitrogen-fixing bacteria related to the genus Azospirillum. Eur Cytokine Netw, 2001 Mar, 12(1), 187 - 93 Rat interleukin-10: production and characterisation of biologically active protein in a recombinant bacterial expression system; Ball C et al.; Interleukin-10 is an anti-inflammatory Th1 immunosuppressive cytokine, the active form of which is a non-covalent homodimer, and which exhibits species-specificity both with respect to structure and biological activity . The rat homologue of IL-10 shares 73% identity with human IL-10 at the amino-acid sequence level, and has, in addition to the two disulphide bonds present in human IL-10, a fifth, unpaired cysteine (cys-149) . Preparation of rat IL-10 by bacterial expression followed by solubilisation and refolding in a glutathione redox system, results in a molecule in which cys-149 is almost entirely oxidised, existing either as disulphide dimer or as a mixed disulphide with glutathione, and which has less than 1% of the activity of the native (cys-149-SH) form of the molecule . Site directed mutagenesis of rat IL-10 to replace cys-149 with tyrosine produces a molecule which readily adopts the active conformation upon solubilisation and refolding, and which is recoverable in good yield from bacterial expression systems . Comparison of the biological activities of rat IL-10tyr149 and commercial rat IL-10 preparations confirms that the activity of native-sequence rat IL-10 is either reduced or absent . It is proposed therefore that the biosynthetic analogue rat IL-10tyr149 is a more useful molecule to investigate the biological actions of IL-10 in the rat. Ann Biol Clin (Paris), 2001 Mar-Apr, 59(2), 177 - 82 {Molecular tools in the epidemiology of tick-borne bacterial diseases}; Parola P et al.; Molecular tools have been used to detect rickettsiae in ticks . In Ixodes ricinus ticks collected in France, we detected for the first time there an emerging pathogen, Rickettsia helvetica, and an Ehrlichia sp, closely related to the agent of human granulocytic ehrlichiosis . In Guadeloupe (French West Indies), we described the occurrence of African tick-bite fever due to Rickettsia africae, which had been previously reported in sub-Saharan Africa only . In Africa, we completed our knowledge about the distribution of R . africae (Mali, Niger, Sudan, Burundi), and detected for the first time Rickettsia mongolotimonae, an emerging pathogen . Anaplasma marginale the agent of bovine anaplasmosis was detected in Mali . Rickettsiae of unknown pathogenicity were detected in Mali and Niger. J Hepatol, 2001 Feb, 34(2), 215 - 21 Ascitic fluid carcinoembryonic antigen and alkaline phosphatase levels for the differentiation of primary from secondary bacterial peritonitis with intestinal perforation; Wu SS et al.; BACKGROUND/AIMS: In cirrhotic patients, spontaneous bacterial peritonitis (SBP) may be difficult to distinguish from secondary peritonitis with occult intestinal perforation; Runyon's criteria (based on ascitic fluid glucose, protein and lactate dehydrogenase levels) are sensitive but not specific . Ascitic fluid carcinoembryonic antigen (CEA) and alkaline phosphatase (AP) are potential markers for secondary peritonitis . METHODS: Ascitic fluid CEA and AP levels were prospectively compared among three subject groups--cirrhotic patients with sterile ascites, cirrhotic patients with SBP, and patients (cirrhotic and non-cirrhotic) with perforation-related secondary peritonitis . RESULTS: The secondary peritonitis group (n = 38 including 11 cirrhotic patients) had significantly higher mean CEA and AP levels than the SBP (n = 34) and sterile ascites patients (n = 63) . Of secondary peritonitis patients, 92% fulfilled predetermined criteria (either CEA >5 ng/ml or AP >240 units/l) versus only 12% of SBP patients; sensitivity was 92% and specificity 88% for differentiating secondary peritonitis from SBP . Runyon's criteria had a sensitivity of 97% and specificity of 56% . Stratification of secondary peritonitis patients by the presence or absence of cirrhosis did not alter our results . CONCLUSIONS: Ascitic fluid CEA or AP elevations appear to be sensitive and specific markers for perforation-related secondary peritonitis in cirrhotic as well as non-cirrhotic patients. Res Microbiol, 2001 Jan-Feb, 152(1), 11 - 6 Second-order selection in bacterial evolution: selection acting on mutation and recombination rates in the course of adaptation; Tenaillon O et al.; The increase in genetic variability of a population can be selected during adaptation, as demonstrated by the selection of mutator alleles . The dynamics of this phenomenon, named second-order selection, can result in an improved adaptability of bacteria through regulation of all facets of mutation and recombination processes. Yi Chuan Xue Bao, 2001, 28(3), 236 - 43 {Construction of a bacterial artificial chromosome (BAC) contig encompassing the bacterial blight resistance gene Xa4 locus in rice}; Jiang GH et al.; The gene Xa4 confers dominantly resistance to rice bacterial blight, which has been finely mapped between RFLP markers G181 and L1044, and co-segregated with the resistance gene homologues sequence marker RS13 . The three markers were used to screen a rice Bacterial Artificial Chromosome (BAC) library constructed from IRBB56, a Xa4-harborring indica variety, resulting in the detection of totally 128 positive clones . Of the 18 positive clones picked out by RS13, 4 and 6 clones were simultaneously detected by G181 and L1044, respectively . Based on their HindIII restriction patterns, 12 clones were selected out to construct a contig that spanned about 420 kb covering the Xa4 locus, which is a solid base for the isolation of Xa4 gene. Compr Ther, 2001 Spring, 27(1), 72 - 7 Utility of prognostic stratification in adults with community-acquired bacterial meningitis; Aronin SI et al.; Prognostic stratification uses baseline clinical features to subdivide patients into subgroups with different risks for a particular outcome . We review the importance of prognostic stratification in internal medicine, in infectious diseases, and in adults with community-acquired bacterial meningitis. J Biol Chem, 2001 Apr 27, 276(17), 14393 - 9 Epub 2001 Jan 22. Overproduction of bacterial protein disulfide isomerase (DsbC) and its modulator (DsbD) markedly enhances periplasmic production of human nerve growth factor in Escherichia coli; Kurokawa Y et al.; Production of eukaryotic proteins with multiple disulfide bonds in the Escherichia coli periplasm often encounters difficulty in obtaining soluble products with native structure . Human nerve growth factor beta (NGF) contains three disulfide bonds between nonconsecutive cysteine residues and forms insoluble aggregates when expressed in E . coli . We now report that overexpression of Dsb proteins known to catalyze formation and isomerization of disulfide bonds can substantially enhance periplasmic production of NGF . A set of pACYC184-based plasmids that permit dsb expression under the araB promoter were introduced into cells carrying a compatible plasmid that expresses NGF . The efficiency of periplasmic production of NGF fused to the OmpT signal peptide was strikingly improved by coexpression of DsbCD or DsbABCD proteins (up to 80% of total NGF produced) . Coexpression of DsbAB was hardly effective, whereas that of DsbAC increased the total yield but not the periplasmic expression . These results suggest synergistic roles of DsbC and DsbD in disulfide isomerization that appear to become limiting upon NGF production . Furthermore, recombinant NGF produced with excess DsbCD (or DsbABCD) was biologically active judged by the neurite outgrowth assay using rat PC12 cells. Virology, 2001 Mar 15, 281(2), 281 - 93 Chemical modification patterns of active and inactive as well as procapsid-bound and unbound DNA-packaging RNAof bacterial virus Phi29; Zhang C et al.; During replication, the lengthy genome of dsDNA viruses is translocated with remarkable velocity into the limited space within the preformed procapsid . We previously found that a viral-encoded RNA (pRNA) played a key role in bacterial virus phi29 DNA translocation . Design of mutant pRNA sets containing two and three inactive mutant pRNAs, respectively, led to the conclusion that the stoichiometry of pRNA in DNA packaging is the common multiple of 2 and 3 . Together with studies using binomial distribution of mutant and wild-type pRNA, it has been confirmed that six pRNAs of phi29 form a hexagonal complex to drive the DNA translocating machine . These findings have brought about commonality between viral DNA packaging and other universal DNA/RNA-riding processes including DNA replication and RNA transcription . Chemical modification was used to compare the structures of active and inactive as well as free and procapsid-bound pRNA . Our results explain why certain pRNA mutants are inactive in DNA packaging while remaining competent in procapsid binding, since the mutations were located in a domain involved in DNA translocation that is dispensable for procapsid binding . A mutant pRNA that had reduced procapsid binding was revealed to have a structural alteration within the procapsid-binding region that may account for the binding deficiency . Chemical probing of procapsid-bound pRNA revealed a large area of protection, while a 3-base bulge, C(18)C(19)A(20), was accessible to chemicals . A pRNA with a deletion of this 3-base bulge was fully competent to form dimers, bind procapsids, and inhibit phi29 virion assembly in vitro; however, its activity in DNA packaging and virion assembly was completely lost . The results suggest that this bulge is not involved in procapsid binding but may interact with other DNA-packaging components . A computer model showing the location of the CCA bulge was presented . J Ethnopharmacol, 2001 Mar 3, 74(3), 231 - 7 Cyclooxygenase inhibiting and anti-bacterial activities of South African Erythrina species; Pillay CC et al.; Aqueous, ethanolic and ethyl acetate extracts of the bark and leaves of five South African Erythrina species Erythrina caffra, Erythrina humeana, Erythrina latissima, Erythrina lysistemon and Erythrina zeyheri were screened for prostaglandin synthesis-inhibitory and anti-bacterial activity . The bark generally displayed higher activity than the leaves in both bioassays . The highest cyclooxygenase inhibiting activity and anti-bacterial activity was recorded for the ethanol and ethyl acetate bark extracts of E . caffra, E . latissima and E . lysistemon . An anti-bacterial compound, 4',5,7-trihydroxy-6-prenylisoflavone, was isolated by bioassay-guided fractionation from bark of E . lysistemon. Proc Natl Acad Sci U S A, 2001 Mar 27, 98(7), 4243 - 8 Vipp1 deletion mutant of Synechocystis: a connection between bacterial phage shock and thylakoid biogenesis? Westphal S, Heins L, Soll J, Vothknecht UC. Plant chloroplasts originated from an endosymbiotic event by which an ancestor of contemporary cyanobacteria was engulfed by an early eukaryotic cell and then transformed into an organelle . Oxygenic photosynthesis is the specific feature of cyanobacteria and chloroplasts, and the photosynthetic machinery resides in an internal membrane system, the thylakoids . The origin and genesis of thylakoid membranes, which are essential for oxygenic photosynthesis, are still an enigma . Vipp1 (vesicle-inducing protein in plastids 1) is a protein located in both the inner envelope and the thylakoids of Pisum sativum and Arabidopsis thaliana . In Arabidopsis disruption of the VIPP1 gene severely affects the plant's ability to form properly structured thylakoids and as a consequence to carry out photosynthesis . In contrast, Vipp1 in Synechocystis appears to be located exclusively in the plasma membrane . Yet, as in higher plants, disruption of the VIPP1 gene locus leads to the complete loss of thylakoid formation . So far VIPP1 genes are found only in organisms carrying out oxygenic photosynthesis . They share sequence homology with a subunit encoded by the bacterial phage shock operon (PspA) but differ from PspA by a C-terminal extension of about 30 amino acids . In two cyanobacteria, Synechocystis and Anabaena, both a VIPP1 and a pspA gene are present, and phylogenetic analysis indicates that VIPP1 originated from a gene duplication of the latter and thereafter acquired its new function . It also appears that the C-terminal extension that discriminates VIPP1 proteins from PspA is important for its function in thylakoid formation. Folia Microbiol (Praha), 2000, 45(3), 197 - 203 From no-confidence to nitric oxide acknowledgement: a story of bacterial nitric-oxide reductase; Koutny M; The review briefly summarizes current knowledge of the bacterial nitric-oxide reductase (NOR) . This membrane enzyme consists of two subunits, the smaller one contains haem C and the larger one two haems B and nonhaem iron . The protein sequence and structure of metal centres demonstrate the relationship of NOR to the family of terminal oxidases . The binuclear Fe-Fe reaction centre, consisting of antiferromagnetically coupled haem B and nonhaem iron, is analogous to Fe-Cu centre of terminal oxidases . The data on the structure and function of NOR and terminal oxidases suggest that all these enzymes are closely evolutionally related . The catalytic properties are determined most of all by the relatively high toxicity of nitric oxide as a substrate and the resulting strong need to maintain its concentration at nanomolar levels . A kinetic model of the action of the enzyme comprises substrate inhibition . NOR does not conserve the free energy of nitric oxide reduction because it does not work as a proton pump and, moreover, the protons coming into the reaction are taken from periplasm, i.e . they do not cross the membrane. Fish Shellfish Immunol, 2001 Jan, 11(1), 23 - 37 Enhanced lysozyme production in Atlantic salmon (Salmo salar L.) macrophages treated with yeast beta-glucan and bacterial lipopolysaccharide; Paulsen SM et al.; Atlantic salmon head kidney macrophages grown in the presence of particulate yeast beta-glucan and bacterial lipopolysaccharide (LPS) showed increased production of lysozyme in the culture supernatants compared to non-treated controls . The increased lysozyme production started at day 3 and was five- to six-fold higher compared to controls at day 6 in culture . Beta-glucan showed an approximate linear dose-response curve between 1 and 250 microg x ml(-1) whereas LPS showed a dose-response curve with a well-defined optimum concentration (10 microg x ml(-1)) . The increase in lysozyme activity was accompanied by an accumulation of lysozyme gene transcript in the stimulated cells . Recombinant human tumor necrosis factor alpha, known for its ability to stimulate lysozyme in human macrophages and to elevate respiratory burst activity of rainbow trout macrophages, failed to stimulate lysozyme production of Atlantic salmon macrophages . Macrophages isolated from fish suffering from a non-lethal Ichthyobodo necator infection displayed a highly increased ability to produce lysozyme in response to both beta-glucan and LPS . As in higher vertebrates, lysozyme production may reflect the differentiation stage of the Atlantic salmon macrophages as well as a direct activation of lysozyme gene transcription by biological response modifiers . The rather late increase in lysozyme production induced by beta-glucan and LPS may thus be explained by stimulation of differentiation of the macrophages in culture eventually combined with direct activation of transcription of the lysozyme gene. Proc R Soc Lond B Biol Sci, 2001 Feb 22, 268(1465), 393 - 8 Coevolution between a cockroach and its bacterial endosymbiont: a biogeographical perspective; Clark JW et al.; Cryptocercus are subsocial, xylophagous cockroaches that live in temperate forests . Like other cockroaches, Cryptocercus harbour endosymbiotic bacteria in their fat bodies . Two species of Cryptocercus occur in the palaearctic, one each in eastern Russia and south-central China . In the USA, there are five species: one in the north-west and four in the south-east . Little is known about the relationship between the Eurasian and North American Cryptocercus or the causes of the disjunct distribution . Here, a molecular phylogeny for six out of the seven Cryptocercus species and their endosymbionts is inferred in an attempt to understand the evolution and biogeography of the genus . Our analysis showed that the North American Cryptocercus are monophyletic, suggesting that a single colonization event was followed by vicariance . There was complete concordance between the host and endosymbiont phylogenetic trees . Divergence estimates based on endosymbiont DNA sequences suggested that the palaearctic and nearctic Cryptocercus diverged 70-115 million years (Myr) ago and the eastern- and western-USA species diverged 53-88 Myr ago . These divergence estimates were correlated with biogeographical events, and a hypothesis is presented to explain the current distribution of Cryptocercus . Our findings suggest that Cryptocercus has had a long evolutionary history, dating back to the Jurassic. Ann N Y Acad Sci, 2000, 917, 165 - 8 Increased sensitivity of the baroreceptor reflex after bacterial endotoxin; Rogausch H et al.; Lipopolysaccharide (LPS), an endotoxin that elicits the production of several cytokines, induces cardiovascular changes characterized by increased perfusion of immune organs and compensatory sympathetic vasoconstriction in other tissues . We therefore hypothesized that to adapt to altered blood flow distribution following LPS administration, changes in the sensitivity of reflexes that control blood pressure would occur . Our data show that the sensitivity of the baroreceptor reflex increases significantly two and three hours after the intravenous administration of a subpyrogenic dose of the endotoxin . This change in sensitivity that could occur at peripheral or central levels may underlie necessary adjustments of cardiovascular mechanisms during the course of certain immune responses. FEMS Microbiol Lett, 2001 Mar 15, 196(2), 135 - 9 Inhibition of bacterial RNA polymerase by the cyanobacterial metabolites 12-epi-hapalindole E isonitrile and calothrixin A; Doan NT et al.; The alkaloid 12-epi-hapalindole E isonitrile, from a cyanobacterial Fischerella species, and the indolophenanthridine calothrixin A, from Calothrix, inhibited Escherichia coli RNA polymerase competitively with respect to ATP, and non-competitively with respect to UTP . The inhibition was dependent on the order of addition of the inhibitors . The K(I) values, with ATP as the variable substrate, were 1.3+/-0.2 mM and 0.23+/-0.11 mM, respectively . Based on comparisons with the sensitivity of whole cells to these inhibitors, it is concluded that other targets in addition to RNA polymerase may also be implicated in their action. Nucleic Acids Res, 2001 Apr 1, 29(7), 1602 - 7 Phylogenetic analysis of tmRNA genes within a bacterial subgroup reveals a specific structural signature; Felden B et al.; Bacterial tmRNA mediates a trans-translation reaction, which permits the recycling of stalled ribosomes and probably also contributes to the regulated expression of a subset of genes . Its action results in the addition of a small number of C-terminal amino acids to protein whose synthesis had stalled and these constitute a proteolytic recognition tag for the degradation of these incompletely synthesized proteins . Previous work has identified pseudoknots and stem-loops that are widely conserved in divergent bacteria . In the present work an alignment of tmRNA gene sequences within 13 beta-proteobacteria reveals an additional sub-structure specific for this bacterial group . This sub-structure is in pseudoknot Pk2, and consists of one to two additional stem-loop(s) capped by stable GNRA tetraloop(s) . Three-dimensional models of tmRNA pseudoknot 2 (Pk2) containing various topological versions of the additional sub-structure suggest that the sub-structures likely point away from the core of the RNA, containing both the tRNA and the mRNA domains . A putative tertiary interaction has also been identified. EMBO Rep, 2001 Mar, 2(3), 229 - 33 Bacterial Na(+)-ATP synthase has an undecameric rotor; Stahlberg H et al.; Synthesis of adenosine triphosphate (ATP) by the F(1)F(0) ATP synthase involves a membrane-embedded rotary engine, the F(0) domain, which drives the extra-membranous catalytic F(1) domain . The F(0) domain consists of subunits a(1)b(2) and a cylindrical rotor assembled from 9-14 alpha-helical hairpin-shaped c-subunits . According to structural analyses, rotors contain 10 c-subunits in yeast and 14 in chloroplast ATP synthases . We determined the rotor stoichiometry of Ilyobacter tartaricus ATP synthase by atomic force microscopy and cryo-electron microscopy, and show the cylindrical sodium-driven rotor to comprise 11 c-subunits. Lett Appl Microbiol, 2001 Mar, 32(3), 211 - 4 Sensitive plate assay for screening and detection of bacterial polyurethanase activity; Howard GT et al.; AIMS: A plate assay to screen and detect bacterial polyurethanase in agar medium containing a colloidal polyester-polyurethane and rhodamine B is presented . METHODS AND RESULTS: Substrate hydrolysis causes the formation of orange fluorescent halos visible upon u.v . irradiation . The logarithm of polyurethanase activity from a purified polyurethanase protein is linearly correlated with the diameter of halos, thereby allowing quantification of polyurethanase activities ranging from 0.81 to 7.29 Units . CONCLUSIONS: The potential advantages of this system are in identification and recovery of viable polyurethanolytic bacteria and quantification of polyurethanase activity . SIGNIFICANCE AND IMPACT OF THE STUDY: These advantages are derived largely from the intense fluorescence observed due to the hydrolysis of substrate reacting with rhodamine B allowing for the use of low substrate concentrations and corresponding decrease in time required detecting low levels of enzyme activity. J Biomater Sci Polym Ed, 2000, 11(11), 1227 - 37 The influence of thrombus components in mediating bacterial adhesion to biomaterials; Lamba NM et al.; Thrombosis and infection represent the two largest limiting factors determining the long term success of implanted biomaterials . Infections associated with biomaterials are difficult to treat, and appear to evade the host defense systems . Mechanisms relating infection to thrombosis are described . Investigations into the role of receptors in mediating adhesion to thrombi are also discussed, in addition to strategies to reduce bacterial adhesion to biomaterial surfaces. MMWR Morb Mortal Wkly Rep, 1999 Sep 10, 48(35), 773 - 7 Resurgent bacterial sexually transmitted disease among men who have sex with men--King County, Washington, 1997-1999; Development of two bacterial artificial chromosome shuttle vectors for a recombination-based cloning and regulated expression of large genes in mammalian cells; Harvard Institute of Human Genetics, Harvard Medical School, Beth Israel Deaconess Medical Center, 4 Blackfan Circle, Boston, MA 02115, USAMost conditional expression vectors designed for mammalian cells have been valuable systems for studying genes of interest by regulating their expressions . The available vectors, however, are reliable for the short-length cDNA clones and not optimal for relatively long fragments of genomic DNA or long cDNAs . Here, we report the construction of two bacterial artificial chromosome (BAC) vectors, capable of harboring large inserts and shuttling among Escherichia coli, yeast, and mammalian cells . These two vectors, pEYMT and pEYMI, contain conditional expression systems which are designed to be regulated by tetracycline and mouse interferons, respectively . To test the properties of the vectors, we cloned in both vectors the green fluorescence protein (GFP) through an in vitro ligation reaction and the 17.8-kb-long X-inactive-specific transcript (Xist) cDNA through homologous recombination in yeast . Subsequently, we characterized their regulated expression properties using real-time quantitative RT-PCR (TaqMan) and RNA-fluorescent in situ hybridization (FISH) . We demonstrate that these two BAC vectors are good systems for recombination-based cloning and regulated expression of large genes in mammalian cells . Biosens Bioelectron, 2001 Jan, 16(1-2), 109 - 13 A fiber-optic lactate sensor based on bacterial cytoplasmic membranes; Ignatov SG et al.; A new type of fiber-optic biosensor based on bacterial cytoplasmic membranes (CPM) as the biological recognition element and an oxygen sensitive dye layer as the transducer is described for the detection of lactate . CPMs from bacteria with an induced lactate oxidase system are adsorbed onto a cellulose disk . The disk is fixed mechanically over an oxygen sensitive siloxane layer on the distal end of an optical fiber . This system detects lactate with no interference from glucose, fructose or glutamic acid. Am Surg, 2000 Oct, 66(10), 947 - 51 Isoproterenol inhibits bacterial lipopolysaccharide-stimulated release of tumor necrosis factor-alpha from human heart tissue; Smart KR Jr et al.; Recent evidence suggests that inflammatory cytokines, particularly tumor necrosis factor alpha (TNF-alpha), may play a role in heart disease . Elevated plasma levels of the cytokine have been reported in congestive heart failure and severe angina and after myocardial infarction . The exact role of TNF-alpha in heart disease and how production is stimulated and regulated in the heart are current areas of investigation . Regarding regulation of production, isoproterenol elevates cyclic AMP and inhibits TNF-alpha release in macrophages . Therefore we hypothesized that stimulation of beta-adrenergic receptors of the sympathetic nervous system would inhibit release of the cytokine from heart tissue . With Institutional Review Board approval and patient consent atrial tissue was obtained during preparation for cardiac bypass . The tissue was divided into segments, placed in culture medium, and incubated for various times in the presence or absence of lipopolysaccharide (LPS) (20 microg/mL) and/or isoproterenol (1 microM) . The medium was removed and analyzed for biologically active TNF-alpha by the L929 cell cytotoxicity assay . Tissue samples were weighed and TNF-alpha release was expressed as pg TNF-alpha/mg tissue . Initially, to determine the time course of release, measurements were made at 2, 5, 10, 15, 30, 60, 120, 180, and 360 minutes after the addition of LPS . Elevated TNF-alpha levels in the culture medium were reliably detected at 360 minutes after exposure to LPS . In atrial tissue obtained from seven patients TNF-alpha released into the culture medium at 360 minutes was 6 +/- 3 pg/mg tissue . In the presence of LPS, levels of the cytokine in the culture medium increased to 604 +/- 233 pg/mg tissue (P < 0.05 vs LPS alone) . When isoproterenol and LPS were simultaneously added to the culture medium release of TNF-alpha was reduced by 87 per cent to 82 +/- 40 pg/mg tissue (P < 0.05 vs LPS alone) . Our results show that activation of the beta-adrenergic receptor inhibits myocardial production of TNF-alpha . This finding suggests that the sympathetic nervous system inhibits production of the cytokine and that impaired sympathetic function in heart failure may play a role in the elevated levels of TNF-alpha. J Math Biol, 2001 Feb, 42(2), 120 - 44 Mathematical models and simulations of bacterial growth and chemotaxis in a diffusion gradient chamber; Chiu C et al.; The diffusion gradient chamber (DGC) is a novel device developed to study the response of chemotactic bacteria to combinations of nutrients and attractants {7} . Its purpose is to characterize genetic variants that occur in many biological experiments . In this paper, a mathematical model which describes the spatial distribution of a bacterial population within the DGC is developed . Mathematical analysis of the model concerning positivity and boundedness of the solutions are given . An ADI (Alternating Direction Implicit) method is constructed for finding numerical solutions of the model and carrying out computer simulations . The numerical results of the model successfully reproduced the patterns that were observed in the experiments using the DGC. Vet Rec, 2001 Feb 10, 148(6), 172 - 5 Acute phase protein responses to uterine bacterial contamination in cattle after calving; Sheldon IM et al.; Repeated ultrasonographic examinations and collections of blood samples and uterine lumenal swabs between seven and 28 days after calving were used to examine the relative effects of bacterial contamination and involution of the uterus on the concentrations of acute phase proteins in the blood of 26 dairy cows . The severity of bacterial contamination, as determined by the total bacterial growth score, was a significant variable for the concentrations of the acute phase proteins alpha1-acid glycoprotein (P < 0.0001), haptoglobin (P < 0.05) and ceruloplasmin (P < 0.0001) . In addition, the concentrations of alpha1-acid glycoprotein and ceruloplasmin were increased in the cows from which Escherichia coli (P < 0.0001) and Arcanobacterium pyogenes (P < 0.05), respectively, were isolated from the uterine lumen . Uterine involution, as determined by the decreasing diameter of the previously gravid uterine horn, was associated with a decrease in the concentrations of alpha1-acid glycoprotein (P < 0.005), haptoglobin (P < 0.05) and ceruloplasmin (P < 0.01) . However, the response of the acute phase proteins to bacterial contamination was independent of the day on which the samples were collected, indicating that their concentrations were increased by bacterial contamination in addition to the changes associated with uterine involution. Dig Dis Sci, 2000 Dec, 45(12), 2313 - 9 Administration of bacterial lipopolysaccharide to rats induces heme oxygenase-1 and formation of antioxidant bilirubin in the intestinal mucosa; Otani K et al.; Heme oxygenase (HO)-1, the rate-limiting enzyme in heme degradation, is induced by oxidative stress and its major end product, bilirubin, is a potent physiological antioxidant . We studied the induction of HO-1 and bilirubin production in intestinal mucosa using a rat model of sepsis . E . coli lipopolysaccharide was administered intraperitonealy to male Wistar rats and intestinal mucosa was harvested . Intestinal lipid peroxides increased significantly at 1 hr and peaked at 170% of the control value at 5 hr . GSH significantly decreased at 3 hr, reaching the nadir of 50% of the control value at 5 hr . HO-1 mRNA was maximally induced fivefold at 3 hr and HO-1 protein maximally increased to 10 times the control value at 7.5 hr . Both bilirubin and bilirubin oxidative metabolites were maximally increased at 10 hr, to 4.3 and 3.7 times the control value, respectively . These data suggest that oxidative stress in sepsis quickly induces HO-1 in intestinal mucosa and that subsequent production of bilirubin works as an antioxidant . The small intestinal mucosa is an active participant in the general response to sepsis. Vaccine, 2001 Mar 21, 19(17-19), 2323 - 8 Peptide and recombinant antigens for protection against bacterial middle ear infection; Bakaletz LO; Passive immunization of chinchillas with serum specific for either LB1 or for LPD-LB1 (f)(2,1,3) prior to challenge with heterologous NTHI isolates (relative to diversity in region three of P5-fimbrin), significantly inhibited the signs and incidence of otitis media (P < or = 0.01) induced by any of the challenge isolates . The ability of these antisera to induce total eradication of NTHI from the nasopharynx was not however equivalent among challenged cohorts . The data thus suggested that while early, complete eradication of NTHI from the nasopharynx was highly protective, reduction of the bacterial load to below a critical threshold level appeared to be similarly effective . Both immunogens thus remain strong vaccine candidates. EMBO Rep, 2000 Sep, 1(3), 239 - 43 Point mutation of bacterial artificial chromosomes by ET recombination; Muyrers JP et al.; Bacterial artificial chromosomes (BACs) offer many advantages for functional studies of large eukaryotic genes . To utilize the potential applications of BACs optimally, new approaches that allow rapid and precise engineering of these large molecules are required . Here, we describe a simple and flexible two-step approach based on ET recombination, which permits point mutations to be introduced into BACs without leaving any other residual change in the recombinant product . Introduction of other modifications, such as small insertions or deletions, is equally feasible . The use of ET recombination to achieve site-directed mutagenesis opens access to a powerful use of BACs and is extensible to DNA molecules of any size in Escherichia coli, including the E . coli chromosome. Biochimie, 2001 Jan, 83(1), 117 - 20 Conserved sequence motif at the C-terminus of the bacterial cell-division protein FtsA; Lowe J et al.; FtsA is an essential part of the septal ring structure in bacterial cell division . Two peptide-protein interactions are known in this process: FtsA and ZipA bind the C-terminus of FtsZ, the bacterial tubulin homologue, which is the first septal component to appear at the septum . Our recent crystal structure of FtsA revealed a possible peptide binding site on FtsA and a long disordered C-terminal region . Here we show that all FtsA proteins contain a conserved 10-13 residue motif at the C-terminal end that may facilitate targeting of downstream septal components. Biochimie, 2001 Jan, 83(1), 91 - 7 Hypothesis: membrane domains and hyperstructures control bacterial division; Norris V et al.; The mechanism responsible for creating the division site in the right place at the right time in bacteria is unknown . It has been attributed to the formation of proteolipid domains in the cytoplasmic membrane surrounding the nucleoids . We interpret the growing evidence for this hypothesis by invoking hyperstructures, which exist at a level of organization intermediate between macromolecules and genes . Non-equilibrium hyperstructures comprise the genes, mRNA proteins and lipids required for a particular function such as cell division, and assemble and disassemble according to the needs of the cell. Dis Aquat Organ, 2001 Jan 26, 44(1), 7 - 16 Pathology associated with an aquareovirus in captive juvenile Atlantic halibut Hippoglossus hippoglossus and an experimental treatment strategy for a concurrent bacterial infection; Cusack RR et al.; A large-scale mortality of larval and juvenile halibut Hippoglossus hippoglossus occurred at a semi-commercial halibut farm in Atlantic Canada . Investigation of the cause revealed aquareovirus particles in necrotic liver tissue of affected fish . Cytopathic effect on CHSE-214 cell lines occurred from all fish cultured for viruses, and the viral morphology of the particles in culture was consistent with that observed in necrotic host tissue . The virus was placed in the family of Reoviridae, genus Aquareovirus based on morphology and RT-PCR results . Multifocal hepatocellular necrosis was a consistent finding in all fish as well as acute necrosis of proximal renal tubules . Concurrent bacterial infections were present in some specimens . Fish experimentally treated with oxytetracycline or a combination of oxytetracycline and chloramine-T had a significantly lower mortality rate than untreated fish . Fish treated with chloramine-T alone had a significantly elevated mortality rate compared to controls . Despite supportive medical therapy, mortality levels in treated and untreated groups remained elevated, supporting the hypothesis that the primary pathogen was of viral origin . This is the first report of elevated mortalities in Atlantic halibut associated with an aquareovirus. Genetika, 2001 Feb, 37(2), 183 - 9 {Effect of integrating the pJFF350 vector into the 85-MDa plasmid of Azospirillum brasilense Sp245 on bacterial flagellation and mobility}; Katsy EI et al.; Results of genetic analysis of three derivatives of Azospirillum brasilense Sp245 (strains BK570, SK051, and SK248) carrying cointegrates of plasmids 85-MDa and pJFF350 (the vector for omegon mutagenesis), which manifest abnormalities in flagellation and motility, are presented . It was shown for the first time that the integration of the suicide vector into one of Azospirillum resident plasmids is accompanied by the formation of various fusion products and changes in flagellation and motility of these bacteria, such as the loss of the polar (Fla) and lateral (Laf) flagella in SK051; inactivation of Fla and Laf in SK248; and Fla-dependent acceleration of expansion in semiliquid media in BK570. Nat Rev Mol Cell Biol, 2000 Nov, 1(2), 110 - 9 Secrets of actin-based motility revealed by a bacterial pathogen; Cameron LA et al.; Actin-based cell motility is a complex process involving a dynamic, self-organizing cellular system . Experimental problems initially limited our understanding of this type of motility, but the use of a model system derived from a bacterial pathogen has led to a breakthrough . Now, all the molecular components necessary for dynamic actin self-organization and motility have been identified, setting the stage for future mechanistic studies. Biologist (London), 2001 Feb, 48(1), 27 - 9 What in earth? Analysing soil bacterial communities; Hodder K; Walk into any field and you will at once see dozens of plant and animal species . However, below your feet and largely unnoticed, lies a population of unseen millions . Can the introduction of powerful molecular biological techniques increase our understanding of how these hidden bacterial communities function in their natural environment? Mol Biotechnol, 2000 Nov, 16(3), 261 - 9 Terminal restriction fragment length polymorphism monitoring of genes amplified directly from bacterial communities in soils and sediments; Bruce KD et al.; Terminal Restriction Fragment Length Polymorphism (T-RFLP) or Fluorescent Polymerase Chain Reaction/Restriction Fragment Length Polymorphism (FluRFLP) have made a significant impact on the way in which PCR products amplified from mixed community DNA extracts have been assessed . Technically, these approaches are essentially the same . PCR products are generated that contain at one 5' end label, typically a fluorescent moiety, that will be detected by a DNA sequencing machine . Upon digestion using a specific restriction endonuclease, labeled and unlabeled fragments are generated . This restriction endonuclease is chosen such that following this digestion, each labeled fragment corresponds to a different sequence variant . During electrophoretic separation, the DNA sequencing machine detects only these labeled fragments and therefore detects only the sequence variants . The aim of this article is to describe the protocols and demonstrate that this profiling can be performed using different DNA sequencing machines . The analysis and applications of this approach are also discussed. Physiol Res, 2000, 49(6), 703 - 10 Recovery of peripheral blood cells in irradiated mice pretreated with bacterial extract IRS-19; Mackova NO et al.; The effect of antigenic bacterial lysate IRS-19 on the recovery of blood cells was studied in mice injured by a single dose of 7 Gy irradiation . The preirradiation administration of IRS-19 accelerated the recovery of leukocytes, reticulocytes and platelets in peripheral blood . The recovery of leukocytes 9-14 days after irradiation in protected animals was accompanied by a higher level of band forms of granulocytes as well as activated lymphoid and monocytoid cells. Transgenic Res, 2001, 10(1), 13 - 9 Accumulation of barley stripe mosaic virus is significantly reduced in transgenic wheat plants expressing a bacterial ribonuclease; Zhang L et al.; An rnc70 gene encoding a mutant bacterial ribonuclease III (RNase III) was introduced into wheat (Triticum aestivum cv . Bobwhite) by microprojectile bombardment . T1, T2, and T3 plants regenerated from three transgenic callus lines were challenged with barley stripe mosaic virus . Plants expressing RNase III exhibited a high level of resistance to the virus infection . This resistance was evidenced by the absence of virus symptoms and reduced accumulation of virions in these plants . The result demonstrates that this pathogen-targeted resistance strategy can be effectively employed in conferring resistance to viral diseases of cereal crops. Scand J Immunol, 2001 Mar, 53(3), 240 - 4 T-cell enforced invariance of the antibody repertoire in the immune response against a bacterial carbohydrate antigen; Rademaekers A et al.; The humoral response against the bacterial polysaccharide antigen alpha(1-->3) dextran (Dex) is controlled by J558 idiotype-(Id) specific T cells . These T cells of which the cell clone 178-4 Ts is a representative by all relevant criteria, recognize J558 Id-bearing B cells in an I-Ed-restricted manner . Costimulation via CD28/B7-1 but not via CD40/CD40L leads to T-cell activation . These T cells do not only suppress B cells producing the immunoglobulin (Ig)G3 isotype but also support the survival and clonal expansion of J558 Id positive B cells both in vivo and in vitro . This T-cell mediated dominance of the J558 idiotype limits the appearance of antibodies carrying other more diverse idiotypes which appear in immunized BALB/c nu/nu mice where no regulatory T cells occur . This T-cell mediated antibody invariance could be a strategy of the immune system responding to highly conserved antigens like polysaccharides, different from those against protein antigens, where diversity is assumed to be the basis for a successful response. Scand J Immunol, 2001 Mar, 53(3), 218 - 26 Immunomodulation using bacterial enterotoxins; Simmons CP et al.; Immunologic unresponsiveness (tolerance) is a key feature of the mucosal immune system, and deliberate vaccination by a mucosal route can effectively induce immune suppression . However, some bacterial-derived proteins, e.g . cholera toxin and the heat labile toxin of Escherichia coli, are immunogenic and immunomodulatory at mucosal surfaces and can effectively adjuvant immune responses to codelivered bystander antigens . This review summarizes some of the structural and biological characteristics of these toxins and provides examples of how these properties have been exploited for tolerance induction and mucosal vaccine development. Scand J Immunol, 2001 Mar, 53(3), 211 - 7 Genetically manipulated bacterial toxin as a new generation mucosal adjuvant; Yamamoto M et al.; Cholera toxin (CT) and heat-labile toxin (LT) of Escherichia coli act as adjuvants for the enhancement of mucosal and serum antibody (Ab) responses to mucosally co-administered protein antigen (Ag) . Both LT and CT induce B7-2 expression on antigen-presenting cells (APCs) for subsequent co-stimulatory signalling to CD4+ T cells . CT directly affects CD4+ T cells activated via the TCR-CD3 complex with selective inhibition of Th1 responses whereas LT maintains Th1 cytokine responses with inhibition of interleukin (IL)-4 production . Interestingly, while CT failed to induce mucosal adjuvant activity in the absence of IL-4, LT did so . Nontoxic mutant (m)CTs (S61F and E112K) retain adjuvant properties by inducing CD4+ Th2 cells, which provided effective help for the Ag-specific mucosal immunoglobulin (Ig)A, as well as serum IgG1, IgE and IgA Ab responses . The mCT E112K has been shown to exhibit two distinct mechanisms for its adjuvanticity . Firstly, mCT enhanced the B7-2 expression of APCs . Secondly, this nontoxic CT derivative directly affected CD4+ T cells and selectively inhibited Th1 cytokine responses . Thus, several lines of evidence indicate that enzyme activity can be separated from adjuvant properties of CT and this offers promise for the development of safe delivery of vaccines for mucosal IgA responses. Mol Microbiol, 2001 Mar, 39(5), 1272 - 84 Type 1 pili-mediated adherence of Escherichia coli strain LF82 isolated from Crohn's disease is involved in bacterial invasion of intestinal epithelial cells; Boudeau J et al.; We previously characterized the invasive ability of Escherichia coli strain LF82, isolated from an ileal biopsy of a patient with Crohn's disease . In the present study, we performed TnphoA insertion mutagenesis to identify genes involved in LF82 invasion of intestinal epithelial cells . Most of the non-invasive mutants had an insertion mutation within the type 1 pili-encoding operon . Two non-invasive fim mutants, which harboured an insertion within the fimI and fimF genes, still adhered but had lost the ability to induce host cell membrane elongations at the sites of contact with the epithelial cells . Transcomplementation experiments with a fim operon cloned from E . coli K-12 restored both invasive ability and the ability to induce host cell membrane elongations . Expression of the cloned LF82 or K-12 fim operon into the non-invasive laboratory strain JM109 did not confer invasive properties . Thus, these findings showed that: (i) type 1 pili-mediated adherence is involved in LF82-induced perturbation of host cell signalling responsible for membrane elongations; (ii) native shafts are required for type 1 pilus-mediated induction of membrane elongations; (iii) this active phenomenon is a key step in the establishment of the invasive process; and (iv) type 1 pili alone are not sufficient to trigger bacterial internalization. Anaesthesia, 2001 Mar, 56(3), 231 - 4 Retention of airborne latex particles by a bacterial and viral filter used in anaesthesia apparatus; Barbara J et al.; We have developed a series of laboratory tests to evaluate the efficiency of a heat and moisture exchanger filter (Pall BB25) in retaining latex particles in order to protect allergic patients during anaesthesia . Latex particles were nebulised with cornstarch as a support and collected for assay in a flask, with or without the filter integrated into the experimental circuit . With the Pall BB25 filter in the circuit, no natural latex proteins were detected by measurement of either total protein or antigenic latex proteins . The Pall BB25 filter may represent a useful means of preventing inhalation of latex particles during anaesthesia in susceptible patients. Oral Surg Oral Med Oral Pathol Oral Radiol Endod, 2001 Mar, 91(3), 353 - 8 Bacterial penetration of restored cavities; Zivkovic S et al.; The aim of this study was to assess the quality of the marginal seals of 7 restoratives by means of a bacterial penetration test in vitro . Sixty intact premolars and third molars that were scheduled for extraction were used in the test . There were 2 experimental groups of teeth, as follows: (1) A class V conventional cavity and a wedge erosion cavity were prepared on the buccal surface and the lingual surface, respectively, of each tooth . (2) A class V conventional cavity and a wedge erosion cavity were prepared on the buccal surface and the lingual surface, respectively, of each tooth with a completely removed enamel layer . The cavities were then reconstructed with different restorative materials . The quality of the marginal seals was evaluated by submerging the teeth in a bacterial suspension and incubating them in an anaerobic milieu at 37 degrees C for 20 hours . The teeth were subsequently processed for histologic data and bacterial staining . The best marginal sealing in both the wedge erosion and the class V cavities was provided by the Herculite/Optibond system and the Valux Plus/Scotchbond Multipurpose system . Bacterial penetration was slightly greater with the Luxat compomer and the Dyrect compomer, as well as with Vitremer glass ionomer cement and Fuji LC glass ionomer cement . The bacterial penetration test showed that the use of restorative material does not entirely eliminate microleakage. Comp Biochem Physiol B Biochem Mol Biol, 2001 Mar, 128(3), 565 - 73 Bacterial expression and characterization of starfish phospholipase A(2); Kishimura H et al.; Phospholipase A(2) (PLA(2)) from the pyloric ceca of the starfish Asterina pectinifera showed high specific activity and characteristic substrate specificity, compared with commercially available PLA(2) from porcine pancreas . To investigate enzymatic properties of the starfish PLA(2) in further detail, we constructed a bacterial expression system for the enzyme . The starfish PLA(2) cDNA isolated previously (Kishimura et al., 2000b . cDNA cloning and sequencing of phospholipase A(2) from the pyloric ceca of the starfish Asterina pectinifera . Comp . Biochem . Physiol . 126B, 579-586) was inserted into the expression plasmid pET-16b and the PLA(2) protein was expressed in Escherichia coli BL21 (DE3) by induction with isopropyl-beta-D(-)-thiogalactopyranoside . The recombinant PLA(2) produced as inclusion bodies was dissociated with 8 M urea and 10 mM 2-mercaptoethanol and renatured by dialyzing against 10 mM Tris--HCl buffer (pH 8.0) . Renatured PLA(2) was purified by subsequent column chromatographies on DEAE--cellulose (DE-52) and Sephadex G-50 . Although an N-terminal Ser in the native starfish PLA(2) was replaced by an Ala in the recombinant PLA(2), the recombinant enzyme showed essentially the same properties as did the native PLA(2) with respect to specific activity, substrate specificity, optimum pH and temperature, and Ca(2+) requirement. Curr Opin Mol Ther, 2000 Feb, 2(1), 94 - 9 Live bacterial delivery systems for development of mucosal vaccines; Thole JE et al.; By expression of foreign antigens in attenuated strains derived from bacterial pathogens and in non-pathogenic commensal bacteria, recombinant vaccines are being developed that aim to stimulate mucosal immunity . Recent advances in the pathogenesis and molecular biology of these bacteria have allowed rational development of new and improved bacterial carriers and more effective gene expression systems . These advances have improved the performance and versatility of these delivery systems to induce mucosal immunity to recombinant antigens in animal models . Application of these (improved) technologies for development of human vaccines is still limited and awaits further exploration. Anal Chem, 2001 Feb 15, 73(4), 746 - 50 Characterization of the protein subset desorbed by MALDI from whole bacterial cells; Ryzhov V et al.; This study characterizes various features of the proteins that are detected in MALDI mass spectra when whole bacteria cells are analyzed, in an effort to understand why some proteins are successfully detected and many others are not . Forty peaks observed in the mass range 4,000-20,000 Da in the spectra of Escherichia coli K-12 and 11775 are tentatively assigned to proteins in a protein database, and these proteins are characterized by cell location, copy number, pI, and hydropathicity . Those detected originate in the cytosol and generally share the traits of high abundance within the cell, strong bacisity, and medium hydrophilicity. FEMS Microbiol Ecol, 2001 Mar, 35(1), 97 - 103 Bacterial populations and processes involved in acetate and propionate consumption in anoxic brackish sediment; Boschker HT et al.; Bacterial populations and pathways involved in acetate and propionate consumption were studied in anoxic brackish sediment from the Grosser Jasmunder Bodden, German Baltic Sea . Uptake of acetate and propionate from the porewater was studied using stable carbon isotope-labeled compounds . Labeled acetate was not produced as an intermediate during propionate uptake experiments, and propionate consumption was not affected by the addition of acetate . In parallel, incorporation of labeled acetate and propionate into phospholipid-derived fatty acids (PLFA) was studied to indicate bacterial populations involved in the consumption of these substrates . The (13)C-acetate label was mainly recovered in even-numbered PLFA (16:1omega7c, 16:0 and 18:1omega7c) . In contrast, primarily odd-numbered PLFA (a15:0, 15:0, 17:1omega6 and 17:0) and the even-numbered i16:0 were labeled after incubation with (13)C-propionate . Although single PLFA labeled with propionate are commonly found in sulfate reducers, the complete PLFA-labeling pattern does not resemble any of the know strains . However, the acetate-labeling pattern is similar to Desulfotomaculum acetoxidans and Desulfofrigus spp., two acetate-consuming, sulfate reducers . In conclusion, our data suggest that acetate and propionate were predominantly consumed by different, specialized groups of sulfate-reducing bacteria. FEBS Lett, 2001 Mar 9, 492(1-2), 160 - 5 Crystal structure of the bacterial cell division regulator MinD; Cordell SC et al.; In bacterial cell division MinD plays a pivotal role, selecting the mid-cell over other sites . With MinC, MinD forms a non-specific inhibitor of division, that interacts with FtsZ . Specificity is provided by MinD's interaction with MinE at the mid-cell . We have solved the crystal structure of MinD-1 from Archaeoglobus fulgidus to 2.6 A by multiple anomalous dispersion . MinD is a classic nucleotide binding protein, related to nitrogenase iron proteins, which have a fold of a seven-stranded parallel beta-sheet, surrounded by alpha-helices . Although MinD, unlike the proteins it interacts with and those it is structurally related to, is a monomer, not a dimer. Proc Natl Acad Sci U S A, 2001 Mar 13, 98(6), 3150 - 5 Direct observation of the enhancement of noncooperative protein self-assembly by macromolecular crowding: indefinite linear self-association of bacterial cell division protein FtsZ; Rivas G et al.; Recent measurements of sedimentation equilibrium and sedimentation velocity have shown that the bacterial cell division protein FtsZ self-associates to form indefinitely long rod-like linear aggregates in the presence of GDP and Mg(2+) . In the present study, the newly developed technique of non-ideal tracer sedimentation equilibrium was used to measure the effect of high concentrations-up to 150 g/liter-of each of two inert "crowder" proteins, cyanmethemoglobin or BSA, on the thermodynamic activity and state of association of dilute FtsZ under conditions inhibiting (-Mg(2+)) and promoting (+Mg(2+)) FtsZ self-association . Analysis of equilibrium gradients of both FtsZ and crowder proteins indicates that, under the conditions of the present experiment, FtsZ interacts with each of the two crowder proteins essentially entirely via steric repulsion, which may be accounted for quantitatively by a simple model in which hemoglobin, albumin, and monomeric FtsZ are modeled as effective spherical hard particles, and each oligomeric species of FtsZ is modeled as an effective hard spherocylinder . The functional dependence of the sedimentation of FtsZ on the concentrations of FtsZ and either crowder indicates that, in the presence of high concentrations of crowder, both the weight-average degree of FtsZ self-association and the range of FtsZ oligomer sizes present in significant abundance are increased substantially. Clin Infect Dis, 2001 Mar 15, 32(6), 897 - 928 Epub 2001 Mar 14. Ticks and tickborne bacterial diseases in humans: an emerging infectious threat; Parola P et al.; Ticks are currently considered to be second only to mosquitoes as vectors of human infectious diseases in the world . Each tick species has preferred environmental conditions and biotopes that determine the geographic distribution of the ticks and, consequently, the risk areas for tickborne diseases . This is particularly the case when ticks are vectors and reservoirs of the pathogens . Since the identification of Borrelia burgdorferi as the agent of Lyme disease in 1982, 15 ixodid-borne bacterial pathogens have been described throughout the world, including 8 rickettsiae, 3 ehrlichiae, and 4 species of the Borrelia burgdorferi complex . This article reviews and illustrate various aspects of the biology of ticks and the tickborne bacterial diseases (rickettsioses, ehrlichioses, Lyme disease, relapsing fever borrelioses, tularemia, Q fever), particularly those regarded as emerging diseases . Methods are described for the detection and isolation of bacteria from ticks and advice is given on how tick bites may be prevented and how clinicians should deal with patients who have been bitten by ticks. Dev Comp Immunol, 2001 May, 25(4), 269 - 77 Bacterial formyl peptide mediated chemotaxis and extracellular acidification in shrimp haemocytes; Yip EC et al.; The bacterial formyl peptide N-formylmethionine-leucine-phenylalanine (fMLP) is a potent chemoattractant for mammalian neutrophils . In this study, we demonstrated the binding of fluorescent dye-conjugated-fMLP to haemocytes of the penaeid shrimp Penaeus penicillatus (Alcock), through the use of flow cytometry . Fluorescence microscopy with rhodamine-fMLP suggested that fMLP receptors are present only in sub-populations of the haemocytes: granulocytes and the semi-granular cells . In addition, fMLP dose-dependently mediated chemotaxis in sub-populations of haemocytes . Microphysiometry experiments demonstrated rapid extracellular acidification upon addition of fMLP, which is in agreement with the observation in neutrophils . t-BOC, the specific fMLP receptor antagonist, was able to block the binding, chemotaxis and extracellular acidification induced by the peptide . The ability of shrimp haemocytes to migrate toward fMLP in vitro suggests that this mechanism may be important for the accumulation of these cells in infected tissues of the shrimps. Gene, 2001 Feb 7, 264(1), 11 - 8 Construction of a PAC vector system for the propagation of genomic DNA in bacterial and mammalian cells and subsequent generation of nested deletions in individual library members; Coren JS et al.; The BAC and PAC cloning systems allow investigators to propagate large genomic DNA fragments up to 300 kb in size in E . colicells.We describe a new PAC shuttle vector that can be propagated in both bacterial and human cells . Specifically, the P1 cloning vector pAd10sacBII was modified by the insertion of a puromycin-resistance gene (pac), the Epstein-Barr Virus (EBV) latent replication origin oriP,and the EBV EBNA1 gene . Transfection studies in HEK 293 cells demonstrated that the modified vector was stably maintained as an episome for at least 30 generations . And since pJCPAC-Mam1 contains a loxP site, genomic DNA cloned into this vector can be subjected to loxP-Cre -mediated deletion events . The transposon vector pTnPGKpuro/loxP was modified to make this system amenable to propagation in human cells by inserting pac, oriP, and EBNA1 elements into the vector (Chatterjee, P.K., Coren, J.C., 1997 . Isolating large nested deletions in PACs and BACs by in vivo selection of P1 headful-packaged products of Cre-catalyzed recombination between the loxP site in PAC and BAC and one introduced in transposition . NAR 25, 2205-2212.) . pTnPGKpuro/loxP-EBV was then used to generate deletions in an individual library member to demonstrate that all of the deletions still contain the required eukaryotic elements and that they were nested . All library members constructed in pJCPAC-Mam1 can be directly transformed into human cells to assess function . And the deletion technology can be used to aid in delineating the boundaries of genes and other cis-acting elements. Biochim Biophys Acta, 2001 Apr 2, 1504(2-3), 311 - 8 Long-lived charge-separated states in bacterial reaction centers isolated from Rhodobacter sphaeroides; van Mourik F et al.; We studied the accumulation of long-lived charge-separated states in reaction centers isolated from Rhodobacter sphaeroides, using continuous illumination, or trains of single-turnover flashes . We found that under both conditions a long-lived state was produced with a quantum yield of about 1% . This long-lived species resembles the normal P(+)Q(-) state in all respects, but has a lifetime of several minutes . Under continuous illumination the long-lived state can be accumulated, leading to close to full conversion of the reaction centers into this state . The lifetime of this accumulated state varies from a few minutes up to more than 20 min, and depends on the illumination history . Surprisingly, the lifetime and quantum yield do not depend on the presence of the secondary quinone, Q(B) . Under oxygen-free conditions the accumulation was reversible, no changes in the normal recombination times were observed due to the intense illumination . The long-lived state is responsible for most of the dark adaptation and hysteresis effects observed in room temperature experiments . A simple method for quinone extraction and reconstitution was developed. Eur J Clin Microbiol Infect Dis, 2001 Jan, 20(1), 65 - 7 Relationship of Ureaplasma urealyticum biovars to the presence or absence of bacterial vaginosis in pregnant women and to the time of delivery; Povlsen K et al.; In a nested case-control study, the occurrence of Ureaplasma urealyticum in cervical specimens from 84 women with idiopathic preterm delivery and from 400 women delivering at term was investigated . The two potential risk factors for preterm delivery, colonization with Ureaplasma urealyticum and bacterial vaginosis, were found to be interdependent variables . The association between these factors and preterm delivery was assessed by regression analysis . Neither colonization with Ureaplasma urealyticum (odds ratio {OR} 0.7, 95% confidence interval {CI} 0.4-1.2) nor bacterial vaginosis (OR 0.8, 95% CI 0.3-1.8) was associated with preterm delivery . In women who delivered preterm, biovar 2 was found significantly more often in those with the clinical diagnosis of bacterial vaginosis (43%) than in those without (5%) (OR 15, 95% CI 1.2-209). Plant Physiol, 2001 Mar, 125(3), 1342 - 53 Comparative sequence analysis of colinear barley and rice bacterial artificial chromosomes; Dubcovsky J et al.; Colinearity of a large region from barley (Hordeum vulgare) chromosome 5H and rice (Oryza sativa) chromosome 3 has been demonstrated by mapping of several common restriction fragment-length polymorphism clones on both regions . One of these clones, WG644, was hybridized to rice and barley bacterial artificial chromosome (BAC) libraries to select homologous clones . One BAC from each species with the largest overlapping segment was selected by fingerprinting and blot hybridization with three additional restriction fragment-length polymorphism clones . The complete barley BAC 635P2 and a 50-kb segment of the rice BAC 36I5 were completely sequenced . A comparison of the rice and barley DNA sequences revealed the presence of four conserved regions, containing four predicted genes . The four genes are in the same orientation in rice, but the second gene is in inverted orientation in barley . The fourth gene is duplicated in tandem in barley but not in rice . Comparison of the homeologous barley and rice sequences assisted the gene identification process and helped determine individual gene structures . General gene structure (exon number, size, and location) was largely conserved between rice and barley and to a lesser extent with homologous genes in Arabidopsis . Colinearity of these four genes is not conserved in Arabidopsis compared with the two grass species . Extensive similarity was not found between the rice and barley sequences other than within the exons of the structural genes, and short stretches of homology in the promoters and 3' untranslated regions . The larger distances between the first three genes in barley compared with rice are explained by the insertion of different transposable retroelements. J Bacteriol, 2001 Apr, 183(7), 2343 - 7 Heteromeric interactions among nucleoid-associated bacterial proteins: localization of StpA-stabilizing regions in H-NS of Escherichia coli; Johansson J et al.; The nucleoid-associated proteins H-NS and StpA in Escherichia coli bind DNA as oligomers and are implicated in gene regulatory systems . There is evidence for both homomeric and heteromeric H-NS-StpA complexes . The two proteins show differential turnover, and StpA was previously found to be subject to protease-mediated degradation by the Lon protease . We investigated which regions of the H-NS protein are able to prevent degradation of StpA . A set of truncated H-NS derivatives was tested for their ability to mediate StpA stability and to form heteromers in vitro . The data indicate that H-NS interacts with StpA at two regions and that the presence of at least one of the H-NS regions is necessary for StpA stability . Our results also suggest that a proteolytically stable form of StpA, StpA(F21C), forms dimers, whereas wild-type StpA in the absence of H-NS predominantly forms tetramers or oligomers, which are more susceptible to proteolysis. J Microbiol Methods, 2001 Apr, 44(3), 253 - 62 Design and evaluation of PCR primers to amplify bacterial 16S ribosomal DNA fragments used for community fingerprinting; Watanabe K et al.; Denaturing gradient gel electrophoresis of PCR-amplified 16S ribosomal DNA (rDNA) fragments has frequently been applied to the fingerprinting of natural bacterial populations (PCR/DGGE) . In this study, sequences of bacterial universal primers frequently used in PCR/DGGE were compared with 16S rDNA sequences that represent recently proposed divisions in the domain Bacteria . We found mismatches in 16S rDNA sequences from some groups of bacteria . Inosine residues were then introduced into the bacterial universal primers to reduce amplification biases caused by these mismatches . Using the improved primers, phylotypes affiliated with Verrucomicrobia and candidate division OP11, were detected in DGGE fingerprints of groundwater populations, which have not been detected by PCR/DGGE with conventional universal primers. Cell Biol Int, 2001, 25(1), 71 - 81 Mycobacterial growth in human macrophages: variation according to donor, inoculum and bacterial strain; Hoal-van Helden EG et al.; The microbicidal capacity of the macrophage is frequently evaded by mycobacteria, leading to tuberculosis (TB) . We investigated a number of parameters affecting the rate of growth of mycobacteria in human monocyte-derived macrophages (MDM) . The results show a great deal of variation in the growth of both Mycobacterium bovis BCG and M . tuberculosis H37Rv, using a large number of human macrophage donors, (132 and 40, respectively), but no correlation was seen with the TB status of the MDM donor . Clumping of the mycobacteria resulted in more vigorous growth in MDM, suggesting that inoculum size could affect disease progression . The growth rates of 17 clinical isolates of M . tuberculosis were measured in macrophages derived from three donors and no consistent or marked differences between isolates were observed over the 5-day period of growth measurement . However, all 17 clinical strains grew consistently faster than H37Rv in the same experiments . Zh Mikrobiol Epidemiol Immunobiol, 2001 Jan-Feb, (1), 82 - 9 {Role of bacterial toxins in pathogenesis of hemolytic-uremic syndrome, caused by enterohemorrhagic Escherichia}; Egorova TN et al.; The pathogenesis of the hemolytico-uremic syndrome (HUS) caused by enterohemorrhagic E . coli (EHEC) has been studied previously rather completely . HUS is characterized by the signs of microangiopathic hemolytic anemia, thrombocytopenia with renal lesions and manifestations of transient disturbances in the functions of the central nervous system . The adherence of EHEC to enterocytes was found to occur in the terminal section of the ileum and the large intestine . This process is realized with involvement intimin, EHEC outer membrane protein . Shiga-like toxins (SLT) produced by EHEC are the leading factor of their pathogenicity . The mechanism of the toxin translocation through enterocytes is not yet clear, still there is no doubt that SLT penetrates into the systemic blood stream . This is indicated by the results of histopathological studies it possible to find the toxin traces on the membranes of endothelial cells of blood vessels . The study reveals that the cells of the vascular epithelium are highly sensitive to SLT . These cells carry receptors Gb3, also known as CD77, on their membranes . Enterohemolysin, serine protease, causing disturbances in the barrier function of the intestine, can be regarded in the pathogenesis of hemorrhagic colitis which develops as the result of the damaging action of EHEC and the above-mentioned toxins . This leads to the increased level of blood systemic bacterial lipopolysaccharides, which may play, in combination with the action of SLT, an important role in the development of multi-organ pathology in HUS patients. Cell Tissue Res, 2001 Jan, 303(1), 129 - 36 Bacterial expression of the shrimp molt-inhibiting hormone (MIH): antibody production, immunocytochemical study and biological assay; Gu PL et al.; Molting in shrimp is controlled by the molt-inhibiting hormone (MIH) and ecdysone . MIH inhibits the synthesis of ecdysone in the Y-organ, resulting in molt suppression; it is a neuropeptide member belonging to the eyestalk CHH/MIH/GIH family . The cloning of MIH (formerly MIH-like) of the shrimp Metapenaeus ensis has been reported in a previous study . To obtain a large quantity of fusion protein for antibody production and biological assay, the cDNA encoding the shrimp MIH was inserted into the pRSET bacterial expression vector . His-tagged fusion protein was produced and purified by an Ni2+-charged affinity column . Polyclonal antibody to rMIH was subsequently obtained by immunizing rabbits with purified recombinant proteins . Results from Western blot analysis indicated that the antibody was specific . Furthermore, results from immunocytochemical analysis showed that specific cells in three different clusters of the X-organ, the sinus gland and the axonal tract of the eyestalk contain MIH . To test for the molt-inhibiting activity of rMIH, shrimp at intermolt stage were injected with rMIH and the molt cycle duration of the injected shrimp was monitored . A significant increase in molt cycle duration was recorded for the shrimp injected with the recombinant protein. Vopr Med Khim, 2000 Nov-Dec, 46(6), 531 - 48 {Bacterial L-asparaginase and glutamin(asparagin)ase: some properties, structure and anti-tumor activity}; Sokolov NN et al.; Experimental material on structurally and functional organization, regulation of biosynthesis and activity, mechanism of action, genetic determinants, heterologous expression of bacterial L-asparaginases is accumulated . The modern approaches to isolation and purification of these enzymes, some questions of practical using in oncology in the schedules combined chemotherapy of leukemia the native and modified forms of L-asparaginases are discussed . The some results before carried out in the IBMC RAMS and number institutes of the Russia on study bacterial L-asparaginases and glutamine(asparagine)ases are summarized. Acta Microbiol Immunol Hung, 2001, 48(1), 107 - 13 Interaction of immunosuppressive drugs in mouse experiments with special regards to bacterial translocation; Anderlik P et al.; Following intraperitoneally (i.p.) applied treatment with 12.5 mg/mouse prednisolonum (PRD) no bacterial translocation (BT) was observed in mice . The PRD treatment applied in combination with lymphotropic cytostatics as dianhydrogalactitol (30 mg/kg i.p.) or chlorpromazine (75 mg/kg i.p.) both causing BT, did not increase the mice's drug sensitivity to the used agents . According to our results, PRD can be suitable for combined application with other immunosuppressive agents as it can increase immunosuppression without increase of side-effects such as those induced by bacterial translocation. Vopr Virusol, 2001 Jan-Feb, 46(1), 22 - 4 {Protective activity of a bacterial plasmid, bearing the gene for the tick-borne encephalitis virus NS1 nonstructural protein}; Timofeev AV et al.; Three intramuscular injections (50 micrograms each) with bacterial plasmid pMV45 carrying nonstructural gene of NS1 protein of tick-borne encephalitis (TBE) virus protected 88% Balb/c mice from lethal challenge with the virus . Antibodies to NS1 nonstructural protein were detected in the sera of vaccinated mice after the challenge . Absence of antibodies to E structural protein indicated absence of manifest infectious process in mice vaccinated with plasmid and challenged with a lethal dose of TBE virus. Nat Biotechnol, 2001 Mar, 19(3), 268 - 72 Acceleration of potato tuber sprouting by the expression of a bacterial pyrophosphatase; Farre EM et al.; Potato is a globally important crop . Unfortunately, potato farming is plagued with problems associated with the sprouting behavior of seed tubers . The data presented here demonstrate that using transgenic technology can influence this behavior . Transgenic tubers cytosolically expressing an inorganic pyrophosphatase gene derived from Escherichia coli under the control of the tuber-specific patatin promoter display significantly accelerated sprouting . The period of presprouting dormancy for transgenic tubers planted immediately after harvest is reduced by six to seven weeks when compared to wild-type tubers . This study demonstrates a method with which to regulate dormancy, an important aspect of potato crop management. Curr Biol, 2001 Feb 6, 11(3), R103 - 5 Bacterial conjugation: running rings around DNA; Egelman EH; Helicases are active in many aspects of DNA replication, recombination, repair and transcription . An integral membrane bacterial protein assembly involved in the transfer of DNA between cells has been shown to resemble a ring helicase, suggesting that it hydrolyzes ATP to pump DNA through a central channel. FEBS Lett, 2001 Jan 26, 489(1), 29 - 33 Protein aggregation as bacterial inclusion bodies is reversible; Carrio MM et al.; Inclusion bodies are refractile, intracellular protein aggregates usually observed in bacteria upon targeted gene overexpression . Since their occurrence has a major economical impact in protein production bio-processes, in vitro refolding strategies are under continuous exploration . In this work, we prove spontaneous in vivo release of both beta-galactosidase and P22 tailspike polypeptides from inclusion bodies resulting in their almost complete disintegration and in the concomitant appearance of soluble, properly folded native proteins with full biological activity . Since, in particular, the tailspike protein exhibits an unusually slow and complex folding pathway involving deep interdigitation of beta-sheet structures, its in vivo refolding indicates that bacterial inclusion body proteins are not collapsed into an irreversible unfolded state . Then, inclusion bodies can be observed as transient deposits of folding-prone polypeptides, resulting from an unbalanced equilibrium between in vivo protein precipitation and refolding that can be actively displaced by arresting protein synthesis . The observation that the formation of big inclusion bodies is reversible in vivo can be also relevant in the context of amyloid diseases, in which deposition of important amounts of aggregated protein initiates the pathogenic process. Genome Res, 2001 Mar, 11(3), 483 - 96 A bacterial artificial chromosome library for sequencing the complete human genome; Osoegawa K et al.; A 30-fold redundant human bacterial artificial chromosome (BAC) library with a large average insert size (178 kb) has been constructed to provide the intermediate substrate for the international genome sequencing effort . The DNA was obtained from a single anonymous volunteer, whose identity was protected through a double-blind donor selection protocol . DNA fragments were generated by partial digestion with EcoRI (library segments 1--4: 24-fold) and MboI (segment 5: sixfold) and cloned into the pBACe3.6 and pTARBAC1 vectors, respectively . The quality of the library was assessed by extensive analysis of 169 clones for rearrangements and artifacts . Eighteen BACs (11%) revealed minor insert rearrangements, and none was chimeric . This BAC library, designated as "RPCI-11," has been used widely as the central resource for insert-end sequencing, clone fingerprinting, high-throughput sequence analysis and as a source of mapped clones for diagnostic and functional studies. FEBS Lett, 2001 Feb 23, 491(1-2), 94 - 8 Guide DNA technique reveals that the protein component of bacterial ribonuclease P is a modifier for substrate recognition; Tanaka T et al.; We developed a guide DNA technique with which the cleavage efficiency of pre-tRNA substrate raised in the RNase P reaction . The 20-mer guide DNAs hybridizing to the upstream region of the cleaving site enhanced the cleavage reactions of RNA substrates by Escherichia coli RNase P . This guide DNA technique was also applicable to cleavage site selection by choosing the DNA-hybridizing site . Results showed that RNase P accepts DNA/RNA double-stranded 5'-leader region with high catalytic efficiency as well as single-stranded RNA region in pre-tRNAs as substrates, which suggests that the protein component of bacterial RNase P prefers bulky nucleotides . The protein component did not affect the normal 5'-processing reaction of pre-tRNAs, but enhanced the mis-cleaving (hyperprocessing) reactions of tRNA in non-cloverleaf folding . Our results suggested that the protein component of RNase P is a modifier for substrate recognition. Med Parazitol (Mosk), 1999 Oct-Dec, (4), 46 - 50 {Use of the recombinant bacterial strain to control blood-sucking mosquito larvae}; Ganushkina LA et al.; The recombinant strain of Methylobacillus flagellatum with the cloned synthesis gene Cry 4B of the toxic Bac . thuringiensis var . israelensis protein proved to be effective against larvae of the Anopheles stephensi, An . atroparvus, An . pulcherrimus, An . superpictus, and An . sacharovi cultured in the laboratory . The use of M . flagellatum in combination with T . pyriformis may greatly expand the scope of use of the recombinant strain to control malaria mosquito larvae . Their combined use shows a 6-fold increase in the rate of strain action and a 4-fold decrease in the concentration of the agent . The optimum effects are shown following 24-hour combined intubation of M . flagellatum and Tetrahymena pyriformis. Pediatr Infect Dis J, 2001 Feb, 20(2), 207 - 13 Bacterial infections and inflammation in the lungs of cystic fibrosis patients; Conese M et al.; The aim of this review is to describe the role of respiratory epithelial cells in processes that contribute to the pathogenesis of lung disease in patients with cystic fibrosis. Biomol Eng, 2001 Mar, 17(3), 75 - 82 Elicitation of predictable immune responses by using live bacterial vectors; Drabner B et al.; There is an increasing need for novel vaccines able to stimulate efficient and long-lasting responses, which have also low production costs . To confer protective immunity following vaccination, the adequate type of response should be elicited . Vaccines based on attenuated bacterial carriers have contained production and delivery costs, and are able to stimulate more potent immune responses than non-replicating formulations . The improved knowledge on carrier physiology and host response, the availability of different mutants and highly sophisticated expression tools, and the possibility of co-administering modulators enable to trigger predictable responses according to the specific needs . Recent studies support the use of attenuated bacteria not only as conventional carriers, but also as a delivery system for DNA vaccines against infectious agents and tumors . In this review we discuss the most widely used bacterial carrier systems for either antigens or nucleic acid vaccines, and the strategies which have been successfully exploited to modulate the immune responses elicited. Biophys J, 2001 Mar, 80(3), 1395 - 405 Is there a conserved interaction between cardiolipin and the type II bacterial reaction center? Wakeham MC, Sessions RB, Jones MR, Fyfe PK. In a recent publication, the structural details of an interaction between the Rhodobacter sphaeroides reaction center and the anionic phospholipid diphosphatidyl glycerol (cardiolipin) were described (K . E . McAuley, P . K . Fyfe, J . P . Ridge, N . W . Isaacs, R . J . Cogdell, and M . R . Jones, 1999, Proc . Natl . Acad . Sci . U.S.A . 96:14706-14711) . This was the first crystallographic description of an interaction between this biologically important lipid and an integral membrane protein and was also the first piece of evidence that the reaction center has a specific interaction with cardiolipin . We have examined the extent to which the residues that interact with the cardiolipin are conserved in other species of photosynthetic bacteria with this type of reaction center and discuss the possibility that this cardiolipin binding site is a conserved feature of these reaction centers . We look at how sequence variations that would affect the shape of the cardiolipin binding site might affect the protein-cardiolipin interaction, by modeling the binding of cardiolipin to the reaction center from Rhodopseudomonas viridis. Indian J Exp Biol, 2000 Feb, 38(2), 167 - 76 Development of a computer software for analysis of SDS-PAGE protein fingerprints of bacterial isolates; Saxena SK et al.; Protein fingerprinting is a widely used technique in epidemiological studies for typing bacterial strains . This study reports the development of a computer based gel analysis system . The system has the capability to analyse SDS-PAGE whole-cell protein profiles using digital image processing techniques . The software incorporates spatial and frequency domain operators for image enhancement, support for geometric correction of images and new algorithms for identification of strain tracks and protein bands . The system also provides facilities for correcting imaging defects for inter-gel comparison, similarity analysis, clustering and pictorial representation of results as a dendrogram . The software is highly interactive, user-friendly and can produce accurate results for differentiation of bacterial strains with minimal overhead of time. Rev Med Interne, 2001 Jan, 22(1), 20 - 9 {Small intestine bacterial overgrowth: six case reports and literature review}; Karsenti D et al.; INTRODUCTION: Small intestinal bacterial overgrowth syndrome (SIBOS) has various clinical and biological presentations . Six observations are described in this review which is aimed at reporting recent data on SIBOS and proposing diagnosis and therapeutic attitudes . CURRENT KNOWLEDGE AND KEY POINTS: Chronic diarrhea, malabsorption syndrome and exsudative enteropathy are the main criteria of diagnosis . Breath hydrogen testing is commonly performed to confirm diagnosis, with a 78% sensitivity and a 89% specificity . The aim of therapy is reparation of malabsorption consequences, reduction of intestinal bacterial overgrowth, and surgical correction of intestinal stasis . In the absence of consensus, norfloxacin or amoxicillin-clavulinic acid (administered for a mean of 7 to 15 days) seem the more appropriate antibiotics . When possible, surgery represents the primary treatment of SIBOS recurrences . FUTURE PROSPECTS AND PROJECTS: Diagnosis of small intestinal bacterial overgrowth syndrome must be evoked on the basis of either surgical or medical context, i.e., the existence of chronic diarrhea, malabsorption syndrome (complete or not), and exsudative enteropathy . This review reports essential factors for diagnosis and treatment. Anal Chem, 2001 Feb 1, 73(3), 492 - 6 Lysing bacterial spores by sonication through a flexible interface in a microfluidic system; Taylor MT et al.; Cell disruptions using ultrasonic energy transmitted through a flexible interface into a liquid region has limitations because the motion of the vibrating tip is not completely transferred into the liquid . To ensure that some degree of contact will be maintained between the ultrasonic horn tip and the flexible interface, the liquid must be pressurized . The pressure conditions that yield consistent coupling between the ultrasonic horn tip and the liquid region were explored in this study by using an analytical model of the system and test fixture experiments . The nature of the interaction between the horn tip and the flexible interface creates pulses of positive pressure rises, increase in temperature, streaming flow, and almost no cavitation in the liquid . There was sufficient energy to create a cloud of microspheres, or beads, that maintain a consistent pattern of ballistic motion in the liquid . The sonication was found to be repeatable by studying video recordings of bead motion and was shown to be statistically consistent using measurements of temperature rise . Sonication of bacterial spores to obtain measurements of released nucleic acid and SEM images of damaged spores were used to verify the effects of liquid pressure on the horn-interface-liquid coupling. J Vector Ecol, 2000 Dec, 25(2), 229 - 39 Bacterial abundance in larval habitats of four species of Anopheles (Diptera: Culicidae) in Belize, Central America; Rejmankova E et al.; Numbers of free-living and attached bacteria were counted in surface waters from larval habitats of four species of Anopheles mosquitoes: Anopheles albimanus Wiedemann, An . darlingi Root, An . vestitipennis Dyar and Knab, and An . pseudopunctiopennis Theobald, using a direct count method and DAPI staining technique . Bacterial counts from larval habitats were compared to those from adjacent open water . Several additional variables such as total suspended solids (TSS), particulate organic carbon (POC), and dissolved organic carbon (DOC) were also recorded in order to establish possible relationships with bacterial characteristics . Our results showed that the waters from larval habitats were enriched with bacteria as well as POC and DOC compared to open water . The major component of all samples consisted of cocci, the proportion of rods was similar and there were significantly more attached rods in habitat samples than in open water samples . Anopheles vestitipennis habitats had the highest values of each of the categories of bacteria as well as of POC and DOC. Rev Prat, 2000 Dec 15, 50(20), 2223 - 30 {Fungal and bacterial nail infections}; Feuilhade de Chauvin M; Fungal and bacterial infections are very common causes of nail deformity . The majority of fungal nail infections are caused by dermatophytes . Dermatophytosis result from a human contamination . A dermatophyte is always a pathogenic agent . Very effective drugs are available to treat dermatophyte nail infections . Yeasts of the genus Candida, notably C . albicans are the second most common cause of nail infection . The infections of nails due to Candida and bacteria are related with Candida sp and bacteria which are common commensals of the gastrointestinal tract, vagina or skin . Except C . albicans which is always a pathogen of skin, the other species of Candida and the bacteria could be a commensal of the skin, a colonizer of a dermatological disease or a true pathogen of nail . It is important to consider these different situations . More rarely, environmental moulds, most often known as saprophytic agents, can affect nails . They do not respond to conventional antifungal drugs . So, their diagnosis do not suffer any error . In order to evaluate properly the patient with possible fungal or bacterial infection of nails and also to choice an accurate therapy, the laboratory confirmation is essential . Clinical diagnosis is not sufficient to distinguish an infection of nails from a dermatological disease (psoriasis, traumatism) and to identify the responsible agent. Cell Mol Life Sci, 2000 Dec, 57(13-14), 1880 - 93 Biosynthesis of cobalamin (vitamin B12): a bacterial conundrum; Raux E et al.; The biosynthesis of cobalamin (vitamin B12) is described, revealing how the concerted action of around 30 enzyme-mediated steps results in the synthesis of one of Nature's most structurally complex 'small molecules' . The plethora of genome sequences has meant that bacteria capable of cobalamin synthesis can be easily identified and their biosynthetic genes compared . Whereas only a few years ago cobalamin synthesis was thought to occur by one of two routes, there are apparently a number of variations on these two pathways, where the major differences seem to be concerned with the process of ring contraction . A comparison of what is currently known about these pathways is presented . Finally, the process of cobalt chelation is discussed and the structure/function of the cobalt chelatase associated with the oxygen-independent pathway (CbiK) is described. Environ Microbiol, 2000 Dec, 2(6), 654 - 65 Bacterial chromosomal painting for in situ monitoring of cultured marine bacteria; Lanoil BD et al.; We previously described a new method, bacterial chromosomal painting (BCP), for the in situ identification of bacterial cells . Here, we describe the application of this technique to study the ecology and physiology of cultured marine pelagic bacteria from the western Sargasso Sea (WSS) . A total of 86 bacteria were isolated from seawater collected from near the surface, at a depth of 250 m and from nutrient-amended seawater incubations . The 10 bacterial isolates that were best represented in environmental genomic DNA from the WSS were selected using reverse genome probing . BCP hybridization cell counts were used to determine the depth-specific distribution of one of the alpha proteobacterial isolates, B5-6, in the WSS during two thermal stratification regimes: stratified and partially mixed . The maximum cell count measured for B5-6 at the summer deep chlorophyll maximum was approximately 4% of the total cell count . This study is the first application of BCP to natural environments. Clin Cardiol, 2001 Feb, 24(2), 166 - 8 Native aortic valve tissue systemic embolization complicating bacterial endocarditis; Garg M et al.; Systemic embolic events are known complications of bacterial endocarditis . Embolization of prosthetic valves has previously been reported in the literature . We report a case of embolization of native aortic valve tissue to the popliteal artery as the presenting event in a patient with subacute bacterial endocarditis . To our knowledge, this rare complication has not been previously reported. Acta Neurochir (Wien), 2000, 142(12), 1377 - 83 External ventricular drainage catheters: effect of surface heparinization on bacterial colonization and infection; Lundberg F et al.; Surface heparinization of central venous catheters has earlier been shown to reduce the frequency of bacterial colonization and septicaemia . The present study was undertaken to investigate the benefit of surface heparinization of external ventricular drainage (EVD) catheters in relation to bacterial colonization, as measured by bacterial growth and examination by a 16S-rRNA PCR assay, of catheters and of samples of cerebrospinal fluid (CSF) . Ninety-eight heparinized and one hundred unheparinized EVD catheters from the same batch of catheters were used . Twenty point five percent of the heparinized and 22.8% (p = 0.63) of the unheparinized EVD catheters were colonized with bacteria . Culture of CSF, which is the definition of clinical infection in this study, yielded growth in 10.3% of patients with heparinized and in 6.3% (p = 0.18) of those with unheparinized catheters . PCR examination yielded positive signal in 31.3% of patients with heparinized catheters and in 37.7% (p = 0.061) of patients without (CSF and catheters) . In the subgroup of patients with subarachnoid haemorrhages, there was a tendency, though not statistically significant, towards a lowered frequency of colonization with 23.1% for heparinized and 33.3% (p = 0.31) for unheparinized catheters . PCR examination did not contribute any further to the diagnostic procedure in the patients concerned . The EVD catheters are skin-penetrating devices and contamination from the skin flora is common . Skin cultures, obtained after skin disinfection and insertion of catheters, showed growth of bacteria in 62% of the patients. Protist, 2000 Dec, 151(4), 317 - 27 Bacterial orthologues indicate the malarial plastid gene ycf24 is essential; Law AE et al.; ycf24 is a well conserved gene found in all major groups of bacteria, as well as on red algal plastid genomes and the vestigal plastid genome of apicomplexan pathogens like the malaria parasite Plasmodium falciparum (ORF470) . Some database annotations describe Ycf24 as an ABC transporter subunit, but we find the level of significance is low . To investigate ycf24's function we disrupted it in the cyanobacterium Synechocystis sp., strain PCC6803 which has a multi-copy genome . This showed ycf24 is essential, partial loss producing a terminal phenotype of chlorosis, reduced cell size, loss of DNA, and a striking arrest in cytokinesis . Attempts to disrupt the single copy of ycf24 in E . coli failed to give stable transformants . When Ycf24 was over-expressed in E . coli as a soluble fusion protein, it localized mostly as a band on either side of the nucleoid and nucleoid partitioning was aberrant . We propose the relict plastid organelle of apicomplexans retains its capacity for protein synthesis because Ycf24 is essential. Cell Mol Life Sci, 1999 Oct 30, 56(5-6), 378 - 83 Bacterial suicide through stress; Aldsworth TG et al.; Outside of the laboratory, bacterial cells are constantly exposed to stressful conditions, and an ability to resist those stresses is essential to their survival . However, the degree of stress required to bring about cell death varies with growth phase, amongst other parameters . Exponential phase cells are significantly more sensitive to stress than stationary phase ones, and a novel hypothesis has recently been advanced to explain this difference in sensitivity, the suicide response . Es