| stability of the agrobacterium tumefaciens virb10 protein is modulated by growth temperature and periplasmic osmoadaption. | export of oncogenic t-dna from the phytopathogen agrobacterium tumefaciens is mediated by the products of the virb operon. it has recently been reported (k. j. fullner and e. w. nester, j. bacteriol. 178:1498-1504, 1996) that dna transfer does not occur at elevated temperatures; these observations correlate well with much earlier studies on the temperature sensitivity of crown gall tumor development on plants. in testing the hypothesis that this loss of dna movement reflects a defect in assembly ... | 1998 | 9852004 |
| the two-component regulators gacs and gaca influence accumulation of the stationary-phase sigma factor sigmas and the stress response in pseudomonas fluorescens pf-5. | three global regulators are known to control antibiotic production by pseudomonas fluorescens. a two-component regulatory system comprised of the sensor kinase gacs (previously called apda or lema) and gaca, a member of the fixj family of response regulators, is required for antibiotic production. a mutation in rpos, which encodes the stationary-phase sigma factor sigmas, differentially affects antibiotic production and reduces the capacity of stationary-phase cells of p. fluorescens to survive ... | 1998 | 9852008 |
| selectivity of ferric enterobactin binding and cooperativity of transport in gram-negative bacteria. | the ligand-gated outer membrane porin fepa serves escherichia coli as the receptor for the siderophore ferric enterobactin. we characterized the ability of seven analogs of enterobactin to supply iron via fepa by quantitatively measuring the binding and transport of their 59fe complexes. the experiments refuted the idea that chirality of the iron complex affects its recognition by fepa and demonstrated the necessity of an unsubstituted catecholate coordination center for binding to the outer mem ... | 1998 | 9852016 |
| comparison of pcr, culture, and serological tests for diagnosis of mycoplasma pneumoniae respiratory tract infection in children. | for diagnosis of mycoplasma pneumoniae infection we compared two rapid tests, pcr and the immunoglobulin m immunofluorescence assay (igm ifa), with culture and the complement fixation test (cft), in a prospective study among 92 children with respiratory tract infection and 74 controls. based on positivity of culture and/or cft as the diagnostic criterion, nine patients (10%) were diagnosed with m. pneumoniae infection. all patients positive by culture were also positive by pcr. in all controls c ... | 1999 | 9854056 |
| a respiratory challenge model for infection with bordetella pertussis: application in the assessment of pertussis vaccine potency and in defining the mechanism of protective immunity. | the evaluation of vaccines for human use usually requires the development of appropriate animal models and the definition of laboratory correlates of immunity. traditionally whole cell pertussis vaccines have been controlled by using an active mouse protection test, which measures protection following intracerebral challenge with bordetella pertussis. however, this test is unsuitable for assessing the potency of the new generation acellular pertussis vaccines. in the present study we demonstrate ... | 1998 | 9855412 |
| [evaluation of the usefulness of bordetella pertussis toxins for serodiagnosis of whooping cough]. | the results of serological tests for the detection of antibodies against pertussis toxin by means of the elisa test, and endotoxin of b. pertussis in the passive haemagglutination test were analysed. the levels of igg, igm and iga antibodies were determined for 95% of serum samples of 108 children in control group (without evidence of respiratory infections) for establishing of the correlation of these with the age of these children. in the light of these data the results were evaluated of testi ... | 1998 | 9857618 |
| nucleotide sequences of genes coding for fimbrial proteins in a cryptic genospecies of haemophilus spp. isolated from neonatal and genital tract infections. | nineteen isolates belonging to a cryptic genospecies of haemophilus (referred to here as genital strains) isolated from genital tract infections (6 strains) and from neonatal infections (13 strains) were studied for fimbrial genes. sixteen strains exhibit peritrichous fimbriae observed by electron microscopy. by pcr with primers corresponding to the extreme ends of the haemophilus influenzae type b (hib) hifa and hifd genes and southern blotting, a hifa-like gene (named ghfa) and a hifd-like gen ... | 1999 | 9864189 |
| immunogenicity of intranasally administered meningococcal native outer membrane vesicles in mice. | colonization of the human nasopharyngeal region by neisseria meningitidis is believed to lead to natural immunity. although the presence of bactericidal antibody in serum has been correlated with immunity to meningococcal disease, mucosal immunity at the portal of entry may also play an important role. this study was undertaken to examine in mice the possibility of safely using native outer membrane vesicles (nomv) not exposed to detergent as an intranasal (i.n.) vaccine. the mucosal and systemi ... | 1999 | 9864204 |
| nonrestricted differential intoxication of cells by pertussis toxin. | after uptake and retrograde transport pertussis toxin acts by adp-ribosylating alpha-gi proteins. we show that uptake via many different receptor proteins followed by retrograde transport and intoxication is not restricted to a particular cell type. the efficiency of cellular intoxication, however, was found to be cell type dependent. | 1999 | 9864250 |
| adhesin expression in matched nasopharyngeal and middle ear isolates of nontypeable haemophilus influenzae from children with acute otitis media. | the hmw1 and hmw2 proteins, hia, and hemagglutinating pili are important adherence factors in nontypeable haemophilus influenzae. to gain insight into the relative importance of these adhesins in nasopharyngeal colonization and localized respiratory tract disease, we assessed their expression in matched nasopharyngeal and middle ear isolates of nontypeable h. influenzae from 17 children with acute otitis media. in all patients, including 11 with bilateral disease, the matched isolates were isoge ... | 1999 | 9864255 |
| etiology of respiratory tract infection in adults in a general practice setting. | a prospective study was conducted over a 3-month winter period in three general practice clinics in an urban population in southern israel to identify the etiological agents of respiratory tract infections (rti) in adults. rti was defined as an acute febrile illness with cough, coryza, sore throat or hoarseness. serum samples were taken from all patients in both the acute and convalescent phases of their illness. tests were conducted for detection of 17 microorganisms known to cause rti, includi ... | 1998 | 9865980 |
| [changes of nmda receptor gene expression in infection brain injury induced by bordetella pertussis in rats]. | n-methyl-d-aspartate receptors (nmdar) in cerebral cortexes of rat brain injury induced by bordetella pertussis (bp) were measured by methods of northern blot analysis and [3h] mk-801 radioligand-receptor binding to study changes and effects of nmdar1 of gene expression in the infection brain injury. the affinity (kd) of nmdar in bp group was significantly decreased [30.5 +/- 3.0 nmol.l-1 (bp), 43.1 +/- 4.2 nmol.l-1 (ns), p < 0.05], but expression of nmdar1 mrna and binding site density (bmax) o ... | 1997 | 9868018 |
| [delayed brain injury induced by bordetella pertussis in rats]. | to induced new model of delayed infection brain injury, we divided randomly 40 adult male sprague-dawley rats into four groups: bordetella pertussis (bp) groups, and normal sailine (ns) groups in 4 h (n = 10) and 24 h (n = 10), respectively, injected bp at 0.2 ml.kg-1 which contained the bacilli in 10.8 x 10(9).ml-1 into the rat left internal carotid artery of bp groups, and injected at the equal volume as control in the same way into ns groups. the water content (wc), evans blue content (eb), c ... | 1997 | 9868080 |
| adp-ribosylation as an intermediate step in inactivation of rifampin by a mycobacterial gene. | mycobacterium smegmatis dsm43756 inactivates rifampin, and the inactivated antibiotic product recovered from culture medium was ribosylated on the 23-oh group. to study this process, the gene responsible for the inactivation was expressed at high levels by the lac promoter in escherichia coli conferring resistance to >500 microg of antibiotic per ml. cell homogenates generated a novel derivative designated rip-tas; in this study, we determined that rip-tas is 23-(o-adp-ribosyl)rifampin. our resu ... | 1999 | 9869590 |
| detection of bordetella pertussis and respiratory synctial virus in air samples from hospital rooms. | to evaluate the distribution of bordetella pertussis and respiratory syncytial virus (rsv) in the hospital setting. | 1998 | 9872529 |
| a natural variant of the cysteine protease virulence factor of group a streptococcus with an arginine-glycine-aspartic acid (rgd) motif preferentially binds human integrins alphavbeta3 and alphaiibbeta3. | the human pathogenic bacterium group a streptococcus produces an extracellular cysteine protease [streptococcal pyrogenic exotoxin b (speb)] that is a critical virulence factor for invasive disease episodes. sequence analysis of the speb gene from 200 group a streptococcus isolates collected worldwide identified three main mature speb (mspeb) variants. one of these variants (mspeb2) contains an arg-gly-asp (rgd) sequence, a tripeptide motif that is commonly recognized by integrin receptors. mspe ... | 1999 | 9874803 |
| expression of heat-shock proteins in streptococcus pyogenes and their immunoreactivity with sera from patients with streptococcal diseases. | the heat-shock response of streptococcus pyogenes following exposure to elevated growth temperatures, and the immunological reactivity of heat-shock proteins (hsps) in streptococcal infections were studied. two major proteins of 65 and 75 kda were expressed when a s. pyogenes strain was shifted from 37 degrees c to heat-shock temperatures of 40, 42 and 45 degrees c. such proteins are members of the groel and dnak families recognised in a western blot assay with polyclonal antibodies against esch ... | 1998 | 9877192 |
| differential stabilities of phosphorylated response regulator domains reflect functional roles of the yeast osmoregulatory sln1 and ssk1 proteins. | osmoregulation in saccharomyces cerevisiae involves a multistep phosphorelay system requiring three proteins, sln1, ypd1, and ssk1, that are related to bacterial two-component signaling proteins, in particular, those involved in regulating sporulation in bacillus subtilis and anaerobic respiration in escherichia coli. the sln1-ypd1-ssk1 phosphorelay regulates a downstream mitogen-activated protein kinase cascade which ultimately controls the concentration of glycerol within the cell under hypero ... | 1999 | 9882653 |
| [experimental study of the relationship between bordetella pertussis and b. parapertussis infections in suckling mice]. | bordetella parapertussis can occasionally be isolated in the late period of epidemic pertussis and even from the same patient infected with b. pertussis, thereby closely related to b. pertussis. compared with b. pertussis, it is more frequently isolated from vaccinated individuals as well. based on the findings, we carried out an experimental study to establish their interrelationship in mice infected with b. parapertussis alone or with both bacteria. the total of 4 groups, each of which constit ... | 1998 | 9884503 |
| quantification of bordetella pertussis in clinical samples by colorimetric detection of competitive pcr products. | quantification of microorganisms is an important part of the normal diagnostic work of a clinical microbiology laboratory. traditionally the diagnosis of pertussis is subject to a yes or no approach with no quantitative dimension. this can, however, be of interest as a factor when judging the risk of a patient spreading the bacterium and as a research tool. the aim of the present study was to develop a pcr-based quantitative assay for bordetella pertussis dna in clinical nasopharyngeal aspirates ... | 1998 | 9890265 |
| the evolutionary origin of the protein-translocating channel of chloroplastic envelope membranes: identification of a cyanobacterial homolog. | the known envelope membrane proteins of the chloroplastic protein import apparatus lack sequence similarity to proteins of other eukaryotic or prokaryotic protein transport systems. however, we detected a putative homolog of the gene encoding toc75, the protein-translocating channel from the outer envelope membrane of pea chloroplasts, in the genome of the cyanobacterium synechocystis sp. pcc 6803. we investigated whether the low sequence identity of 21% reflects a structural and functional rela ... | 1999 | 9892711 |
| expression of bvgas of bordetella pertussis represses flagellar biosynthesis of escherichia coli. | bvgas is a two-component system of bordetella pertussis involved in the reciprocal regulation of the virulence genes and the flagellar biosynthesis. in this study, we found that expression of bvgas in escherichia coli also results in reduced motility. the repression was relieved by the addition of known chemical modulators of bvgas such as mgso4 and nicotinic acid, indicating that functional bvgas proteins are required for the negative control of e. coli motility. in addition, bvgas repressed th ... | 1999 | 9914310 |
| vaccination against anthrax with attenuated recombinant strains of bacillus anthracis that produce protective antigen. | the protective efficacy of several live, recombinant anthrax vaccines given in a single-dose regimen was assessed with hartley guinea pigs. these live vaccines were created by transforming deltaanr and deltasterne, two nonencapsulated, nontoxinogenic strains of bacillus anthracis, with four different recombinant plasmids that express the anthrax protective antigen (pa) protein to various degrees. this enabled us to assess the effect of the chromosomal background of the strain, as well as the amo ... | 1999 | 9916059 |
| intracellular delivery of a cytolytic t-lymphocyte epitope peptide by pertussis toxin to major histocompatibility complex class i without involvement of the cytosolic class i antigen processing pathway. | a cd8(+) cytolytic t-lymphocyte (ctl) response to antigen-presenting cells generally requires intracellular delivery or synthesis of antigens in order to access the major histocompatibility complex (mhc) class i processing and presentation pathway. to test the ability of pertussis toxin (pt) to deliver peptides to the class i pathway for ctl recognition, we constructed fusions of ctl epitope peptides with a genetically detoxified derivative of pt (pt9k/129g). two sites on the a (s1) subunit of p ... | 1999 | 9916065 |
| a controlled clinical study of the effect of nasal immunization with a streptococcus mutans antigen alone or incorporated into liposomes on induction of immune responses. | recent attention to mucosal immunization strategies has been focused on the nasal route for vaccine delivery. this study was designed to determine the effectiveness of a liposome-protein vaccine compared to that of a protein-only vaccine in inducing immune responses in humans. healthy subjects were randomly assigned to two groups and immunized intranasally with a crude antigen preparation rich in glucosyltransferase (c-gtf) from streptococcus mutans, alone or in liposomes. parotid saliva, nasal ... | 1999 | 9916067 |
| characterization of candidate live oral salmonella typhi vaccine strains harboring defined mutations in aroa, aroc, and htra. | the properties of two candidate salmonella typhi-based live oral typhoid vaccine strains, brd691 (s. typhi ty2 harboring mutations in aroa and aroc) and brd1116 (s. typhi ty2 harboring mutations in aroa, aroc, and htra), were compared in a number of in vitro and in vivo assays. brd1116 exhibited an increased susceptibility to oxidative stress compared with brd691, but both strains were equally resistant to heat shock. both strains showed a similar ability to invade caco-2 and ht-29 epithelial ce ... | 1999 | 9916080 |
| identification and characterization of ptlc, an essential component of the pertussis toxin secretion system. | ptlc is a member of a set of proteins necessary for the secretion of pertussis toxin (pt) from bordetella pertussis. using polyclonal antibodies specific for ptlc, we identified ptlc as a protein with an apparent molecular weight of 85,000 that localizes to the membrane fraction of bacterial cell extracts. we found that a mutant strain of b. pertussis that contains an in-frame deletion in ptlc is unable to secrete pt and that pt secretion is fully restored by expressing ptlc in trans, indicating ... | 1999 | 9916087 |
| cytotoxic action of serratia marcescens hemolysin on human epithelial cells. | incubation of human epithelial cells with nanomolar concentrations of chromatographically purified serratia marcescens hemolysin (shla) caused irreversible vacuolation and subsequent lysis of the cells. vacuolation differed from vacuole formation by helicobacter pylori vaca. sublytic doses of shla led to a reversible depletion of intracellular atp. restoration to the initial atp level was presumably due to the repair of the toxin damage and was inhibited by cycloheximide. pores formed in epithel ... | 1999 | 9916096 |
| characterization of a waaf (rfaf) homolog expressed by haemophilus ducreyi. | haemophilus ducreyi lipooligosaccharide (los) is capable of inducing an inflammatory response in skin (a. a. campagnari, l. m. wild, g. griffiths, r. j. karalus, m. a. wirth, and s. m. spinola, infect. immun. 59:2601-2608, 1991) and likely contributes to the virulence of this sexually transmitted pathogen (b. a. bauer, m. k. stevens, and e. j. hansen, infect. immun. 68:4290-4298, 1998). an open reading frame in h. ducreyi 35000 was found to encode a predicted protein that was 59% identical to th ... | 1999 | 9916106 |
| quantification of bacterial lipopolysaccharides by the purpald assay: measuring formaldehyde generated from 2-keto-3-deoxyoctonate and heptose at the inner core by periodate oxidation. | we have adapted the purpald assay (m. s. quesenberry and y. c. lee, anal. biochem. 234, 50-55, 1996) to quantify lipopolysaccharide (lps) content in solution in 96-well microtiter plates at room temperature. this method employs the oxidation of unsubstituted terminal vicinal glycol groups in 2-keto-3-deoxyoctonate (kdo) and l-(or d-)glycero-d-manno-heptose of lps molecules by periodate to release formaldehyde. the formaldehyde is quantified at 550 nm (or 530-570 nm) by reacting with purpald reag ... | 1999 | 9918668 |
| [comparative analysis of bordetella pertussis strains isolated from patients in years 1995-1998 and in 1968]. | | 1998 | 9919931 |
| time-course of infection and responses in a coughing rat model of pertussis. | adult female sprague-dawley rats were challenged intrabronchially with bordetella pertussis strain 18-323 embedded in fine agarose beads and the time-course of infection and other events was determined. there was a steady decline in the numbers of b. pertussis recovered from the rat lungs, with clearance of the infection in most animals by day 12. leucocytosis, lung inflammation and an increase in total serum ige in the rats as a result of the challenge were highest around day 10, which was coin ... | 1999 | 9920131 |
| a putative adhesin gene cloned from campylobacter jejuni. | thirteen campylobacter jejuni strains of human origin showed differing behaviours when analysed for their ability to bind the caco-2 cell line in vitro, suggesting variations in genetic complements and/or regulation. we designed an oligonucleotide probe corresponding to a highly conserved part of adhesins from various gram-negative bacteria. among our laboratory collection, southern hybridization has demonstrated that only a discrete number of strains harbour this sequence. the corresponding gen ... | 1998 | 9921579 |
| immunochemical analysis of ump kinase from escherichia coli. | mono- and polyclonal antibodies directed against ump kinase from escherichia coli were tested with the intact protein or with fragments obtained by deletion mutagenesis. as detected in enzyme-linked immunosorbent assay tests, the carboxy-terminal quarter of ump kinase is immunodominant. polyclonal antibodies inhibited the enzyme activity with partial or total loss of allosteric effects exerted by utp and gtp, respectively. these data indicate that the utp and gtp binding sites in ump kinase are ... | 1999 | 9922246 |
| phaf, a polyhydroxyalkanoate-granule-associated protein of pseudomonas oleovorans gpo1 involved in the regulatory expression system for pha genes. | the phac1 gene codes for the medium-chain-length polyhydroxyalkanoate (mcl pha) synthase of pseudomonas oleovorans gpo1, which produces mcl pha when grown in an excess of carbon source and under nitrogen limitation. in this work, we have demonstrated, by constructing a recombinant p. oleovorans strain carrying a phac1::lacz reporter system, that the phac1 gene is expressed efficiently in the presence of octanoic acid while its expression is repressed when glucose or citrate is used as the carbon ... | 1999 | 9922249 |
| sequence and function of luxu: a two-component phosphorelay protein that regulates quorum sensing in vibrio harveyi. | vibrio harveyi regulates the expression of bioluminescence (lux) in response to cell density, a phenomenon known as quorum sensing. in v. harveyi, two independent quorum-sensing systems exist, and each produces, detects, and responds to a specific cell density-dependent autoinducer signal. the autoinducers are recognized by two-component hybrid sensor kinases called luxn and luxq, and sensory information from both systems is transduced by a phosphorelay mechanism to the response regulator protei ... | 1999 | 9922254 |
| identification of a vibrio cholerae rtx toxin gene cluster that is tightly linked to the cholera toxin prophage. | we identify and characterize a gene cluster in el tor vibrio cholerae that encodes a cytotoxic activity for hep-2 cells in vitro. this gene cluster contains four genes and is physically linked to the cholera toxin (ctx) element in the v. cholerae genome. we demonstrate by using insertional mutagenesis that this gene cluster is required for the cytotoxic activity. the toxin, rtxa, resembles members of the rtx (repeats in toxin) toxin family in that it contains a gd-rich repeated motif. like other ... | 1999 | 9927695 |
| activation of nitric oxide release and oxidative metabolism by leukotrienes b4, c4, and d4 in human polymorphonuclear leukocytes. | because arachidonate metabolites are potent mediators of inflammation, we have studied the effects of leukotriene b4 (ltb4) and the cysteinyl leukotrienes c4 and d4 (ltc4 and ltd4) on the release of nitric oxide (no), in vitro, by human polymorphonuclear granulocytes (pmn). two independent and highly sensitive real-time methods were used for these studies, ie, the no-dependent oxidation of oxyhemoglobin (hbo2) to methemoglobin and a no-sensitive microelectrode. when activated with ltb4, ltc4, or ... | 1999 | 9949184 |
| analysis of rpos mrna in salmonella dublin: identification of multiple transcripts with growth-phase-dependent variation in transcript stability. | in salmonella dublin, rpos encodes an alternative sigma factor of the rna polymerase that activates a variety of stationary-phase-induced genes, including some virulence-associated genes. in this work, we studied the regulation and transcriptional organization of rpos during growth. we found two transcripts, 2.3 and 1.6 kb in length, that represent the complete rpos sequence. the 2.3-kb transcript is a polycistronic message that also includes the upstream nlpd gene. it is driven by a weak promot ... | 1999 | 9973354 |
| direct delivery of the bordetella pertussis adenylate cyclase toxin to the mhc class i antigen presentation pathway. | among bacterial toxins, the adenylate cyclase toxin of bordetella pertussis (cyaa) has a unique mechanism of entry that consists in the direct translocation of its catalytic domain across the plasma membrane of target cell, a mechanism supposed to be independent of any endocytic pathway. here, we report that the cyaa toxin is delivered to the cytosolic pathway for mhc class i-restricted ag presentation. using peritoneal macrophages as apc, we show that the ova 257-264 cd8+ epitope genetically in ... | 1999 | 9973458 |
| nested duplex pcr to detect bordetella pertussis and bordetella parapertussis and its application in diagnosis of pertussis in nonmetropolitan southeast queensland, australia. | a duplex pcr to detect bordetella pertussis and bordetella parapertussis was developed with the insertion sequences is481 (b. pertussis) and is1001 (b. parapertussis) and evaluated with specimens from 520 consecutive patients presenting with possible pertussis. no culture-positive-pcr-negative results occurred, giving the method a sensitivity of 100%. for b. pertussis, 58 of 520 patients (11.2%) were positive by pcr compared to 17 of 520 patients positive (3.3%) by culture. for b. parapertussis, ... | 1999 | 9986820 |
| the structural and functional organization of h-ns-like proteins is evolutionarily conserved in gram-negative bacteria. | the structural gene of the h-ns protein, a global regulator of bacterial metabolism, has been identified in the group of enterobacteria as well as in closely related bacteria, such as erwinia chrysanthemi and haemophilus influenzae. isolated outside these groups, the bph3 protein of bordetella pertussis exhibits a low amino acid conservation with h-ns, particularly in the n-terminal domain. to obtain information on the structure, function and/or evolution of h-ns, we searched for other h-ns-rela ... | 1999 | 9987132 |
| characterization of the c-terminal domain essential for toxic activity of adenylate cyclase toxin. | adenylate cyclase toxin (cyaa) of bordetella pertussis belongs to the rtx family of toxins. these toxins are characterized by a series of glycine- and aspartaterich nonapeptide repeats located at the c-terminal half of the toxin molecules. for activity, rtx toxins require ca2+, which is bound through the repeat region. here, we identified a stretch of 15 amino acids (block a) that is located c-terminally to the repeat and is essential for the toxic activity of cyaa. block a is required for the i ... | 1999 | 9987138 |
| role of antibodies against bordetella pertussis virulence factors in adherence of bordetella pertussis and bordetella parapertussis to human bronchial epithelial cells. | immunization with whole-cell pertussis vaccines (wcv) containing heat-killed bordetella pertussis cells and with acellular vaccines containing genetically or chemically detoxified pertussis toxin (pt) in combination with filamentous hemagglutinin (fha), pertactin (prn), or fimbriae confers protection in humans and animals against b. pertussis infection. in an earlier study we demonstrated that fha is involved in the adherence of these bacteria to human bronchial epithelial cells. in the present ... | 1999 | 10024542 |
| role of bordetella pertussis virulence factors in adherence to epithelial cell lines derived from the human respiratory tract. | during colonization of the respiratory tract by bordetella pertussis, virulence factors contribute to adherence of the bacterium to the respiratory tract epithelium. in the present study, we examined the roles of the virulence factors filamentous hemagglutinin (fha), fimbriae, pertactin (prn), and pertussis toxin (pt) in the adherence of b. pertussis to cells of the human bronchial epithelial cell line nci-h292 and of the laryngeal epithelial cell line hep-2. using b. pertussis mutant strains an ... | 1999 | 10024543 |
| a 55-kilodalton immunodominant antigen of porphyromonas gingivalis w50 has arisen via horizontal gene transfer. | a 55-kda outer membrane protein of porphyromonas gingivalis w50 is a significant target of the serum immunoglobulin g antibody response of periodontal disease patients and hence may play an important role in host-bacterium interactions in periodontal disease. the gene encoding the 55-kda antigen (ragb, for receptor antigen b) was isolated on a 9.5-kb partial sau3ai fragment of p. gingivalis w50 chromosomal dna in puc18 by immunoscreening with a monoclonal antibody to this antigen. the 1.6-kb ope ... | 1999 | 10024556 |
| linear peptide specificity of bovine antibody responses to p67 of theileria parva and sequence diversity of sporozoite-neutralizing epitopes: implications for a vaccine. | a stage-specific surface antigen of theileria parva, p67, is the basis for the development of an anti-sporozoite vaccine for the control of east coast fever (ecf) in cattle. by pepscan analysis with a series of overlapping synthetic p67 peptides, the antigen was shown to contain five distinct linear peptide sequences recognized by sporozoite-neutralizing murine monoclonal antibodies. three epitopes were located between amino acid positions 105 to 229 and two were located between positions 617 to ... | 1999 | 10024569 |
| the levels and bactericidal capacity of antibodies directed against the uspa1 and uspa2 outer membrane proteins of moraxella (branhamella) catarrhalis in adults and children. | the uspa1 and uspa2 proteins from moraxella catarrhalis share antigenic epitopes and are promising vaccine candidates. in this study, the levels and bactericidal activities of antibodies in sera from healthy adults and children toward uspa1 and uspa2 from the o35e strain were measured. human sera contained antibodies to both proteins, and the levels of immunoglobulin g (igg) antibodies were age dependent. adult sera had significantly higher titers of igg than child sera (p < 0.01). the igg3 tite ... | 1999 | 10024576 |
| characterization of human bactericidal antibodies to bordetella pertussis. | the bordetella pertussis brka protein protects against the bactericidal activity of complement and antibody; however, some individuals mount an immune response that overcomes this bacterial defense. to further characterize this process, the bactericidal activities of sera from 13 adults with different modes of exposure to b. pertussis (infected as adults, occupational exposure, immunized with an acellular vaccine, or no identified exposure) against a wild-type strain and a brka complement-sensit ... | 1999 | 10024590 |
| probing the function of bordetella bronchiseptica adenylate cyclase toxin by manipulating host immunity. | we have examined the role of adenylate cyclase-hemolysin (cyaa) by constructing an in-frame deletion in the bordetella bronchiseptica cyaa structural gene and comparing wild-type and cyaa deletion strains in natural host infection models. both the wild-type strain rb50 and its adenylate cyclase toxin deletion (deltacyaa) derivative efficiently establish persistent infections in rabbits, rats, and mice following low-dose inoculation. in contrast, an inoculation protocol that seeds the lower respi ... | 1999 | 10024599 |
| surface expression of a protective recombinant pertussis toxin s1 subunit fragment in streptococcus gordonii. | in this study, the expression of the bordetella pertussis s1 subunit was tested in streptococcus gordonii, a commensal oral bacterium which has the potential to be a live oral vaccine vehicle. the dna fragment encoding the n-terminal 179 amino acids of the s1 subunit was ligated into the middle part of spap, the surface protein antigen p1 gene originating from streptococcus mutans. the resulting construct, carried on the escherichia coli-streptococcus shuttle vector pdl276, was introduced into s ... | 1999 | 10024603 |
| the effect of cigarette smoke on adherence of respiratory pathogens to buccal epithelial cells. | smoking is associated with an increased risk of respiratory tract infection in adults. in children, exposure to cigarette smoke is a risk factor for respiratory tract infection and bacterial meningitis: active smoking and passive exposure to cigarette smoke is also associated with carriage of some potentially pathogenic species of bacteria in both adults and children. the aims of the study were to determine the effect of active smoking on: (1) bacterial binding to epithelial cells; (2) expressio ... | 1999 | 10030544 |
| the vitronectin receptor and its associated cd47 molecule mediates proinflammatory cytokine synthesis in human monocytes by interaction with soluble cd23. | the vitronectin receptor, alphavbeta3 integrin, plays an important role in tumor cell invasion, angiogenesis, and phagocytosis of apoptotic cells. cd47, a member of the multispan transmembrane receptor family, physically and functionally associates with vitronectin receptor (vnr). although vitronectin (vn) is not a ligand of cd47, anti-cd47 and beta3 mabs suppress vn, but not fibronectin (fn) binding and function. here, we show that anti-cd47, anti-beta3 mab and vn, but not fn, inhibit scd23-med ... | 1999 | 10037797 |
| efflux-mediated aminoglycoside and macrolide resistance in burkholderia pseudomallei. | burkholderia pseudomallei, the causative agent of melioidosis, is intrinsically resistant to a wide range of antimicrobial agents including beta-lactams, aminoglycosides, macrolides, and polymyxins. we used tn5-ot182 to mutagenize b. pseudomallei to identify the genes involved in aminoglycoside resistance. we report here on the identification of amrab-opra, a multidrug efflux system in b. pseudomallei which is specific for both aminoglycoside and macrolide antibiotics. we isolated two transposon ... | 1999 | 10049252 |
| complete sequence of a 184-kilobase catabolic plasmid from sphingomonas aromaticivorans f199. | the complete 184,457-bp sequence of the aromatic catabolic plasmid, pnl1, from sphingomonas aromaticivorans f199 has been determined. a total of 186 open reading frames (orfs) are predicted to encode proteins, of which 79 are likely directly associated with catabolism or transport of aromatic compounds. genes that encode enzymes associated with the degradation of biphenyl, naphthalene, m-xylene, and p-cresol are predicted to be distributed among 15 gene clusters. the unusual coclustering of gene ... | 1999 | 10049392 |
| gi protein modulation induced by a selective inverse agonist for the peripheral cannabinoid receptor cb2: implication for intracellular signalization cross-regulation. | the peripheral cannabinoid receptor (cb2) is a g protein-coupled receptor that is both positively and negatively coupled to the mitogen-activated protein kinase (mapk) and camp pathways, respectively, through a bordetella pertussis toxin-sensitive g protein. cb2 receptor-transfected chinese hamster ovary cells exhibit high constitutive activity blocked by the cb2-selective ligand, sr 144528, working as an inverse agonist. we showed here that in addition to the inhibition of autoactivated cb2 in ... | 1999 | 10051530 |
| localization of non-mhc collagen-induced arthritis susceptibility loci in dba/1j mice. | one approach to understanding common human diseases is to determine the genetic defects responsible for similar diseases in animal models and place those defective genes in their corresponding biochemical pathways. our laboratory is working with an animal model for human rheumatoid arthritis called collagen-induced arthritis (cia). we are particularly interested in determining the location of disease-predisposing loci. to that end, we performed experiments to localize susceptibility loci for cia ... | 1999 | 10051620 |
| surface proteins of gram-positive bacteria and mechanisms of their targeting to the cell wall envelope. | the cell wall envelope of gram-positive bacteria is a macromolecular, exoskeletal organelle that is assembled and turned over at designated sites. the cell wall also functions as a surface organelle that allows gram-positive pathogens to interact with their environment, in particular the tissues of the infected host. all of these functions require that surface proteins and enzymes be properly targeted to the cell wall envelope. two basic mechanisms, cell wall sorting and targeting, have been ide ... | 1999 | 10066836 |
| temporal trends in the population structure of bordetella pertussis during 1949-1996 in a highly vaccinated population. | the population structure of bordetella pertussis in the netherlands in 5 successive periods, encompassing 1949-1996, was analyzed by dna typing ("fingerprinting"). in 10 years following the introduction of wide-scale vaccination in 1953, a decrease in genotypic diversity (gd) was observed, suggesting clonal expansion of strains that were adapted to vaccine-induced immunity. in subsequent periods, gd increased to prevaccination levels, probably reflecting a gradual adaptation of the b. pertussis ... | 1999 | 10068587 |
| rat liver gtp-binding proteins mediate changes in mitochondrial membrane potential and organelle fusion. | the variety of mitochondrial morphology in healthy and diseased cells can be explained by regulated mitochondrial fusion. previously, a mitochondrial outer membrane fraction containing fusogenic, aluminum fluoride (alf4)-sensitive gtp-binding proteins (mtg) was separated from rat liver (j. d. cortese, exp. cell res. 240: 122-133, 1998). quantitative confocal microscopy now reveals that mtg transiently increases mitochondrial membrane potential (deltapsi) when added to permeabilized rat hepatocyt ... | 1999 | 10069988 |
| identification of the tlidef abc transporter specific for lipase in pseudomonas fluorescens sik w1. | pseudomonas fluorescens, a gram-negative psychrotrophic bacterium, secretes a thermostable lipase into the extracellular medium. in our previous study, the lipase of p. fluorescens sik w1 was cloned and expressed in escherichia coli, but it accumulated as inactive inclusion bodies. amino acid sequence analysis of the lipase revealed a potential c-terminal targeting sequence recognized by the atp-binding cassette (abc) transporter. the genetic loci around the lipase gene were searched, and a secr ... | 1999 | 10074078 |
| analysis with a combination of macrorestriction endonucleases reveals a high degree of polymorphism among bordetella pertussis isolates in eastern france. | from 1990 to 1996, routine screening for whooping cough identified 399 patients with a calmodulin-dependent adenylate cyclase-positive test result and yielded 69 bordetella pertussis isolates. none of the patients were fully vaccinated, and most were less than 6 months old. analysis of total dna by pulsed-field gel electrophoresis (pfge) after xbai, spei, or drai macrorestriction yielded 19, 15, and 5 different patterns, respectively, whereas ribotyping failed to demonstrate any strain polymorph ... | 1999 | 10074527 |
| an aerosol challenge model of bordetella pertussis infection as a potential bioassay for acellular pertussis vaccines. | whole cell and five different types of acellular pertussis vaccine were assayed using a mouse aerosol challenge model which permitted delivery of a controlled, consistent dose of bordetella pertussis to the lower respiratory tract. using this system, the viable counts in the lungs of vaccinated mice were immunisation dose-dependent and allowed the protective capacity of different vaccine preparations to be distinguished. this model may thus provide the basis for a protection assay for pertussis ... | 1999 | 10075163 |
| identification of bordetella pertussis virulence-associated outer membrane proteins. | bordetella pertussis virulence-associated 30-, 32-, 90- and 95-kda outer membrane proteins were purified and their n-terminal amino acid sequences were determined. the 30- and 32-kda outer membrane proteins showed identity to the c-terminal region of the precursors of the serum resistance protein (brka) and the tracheal colonization factor, respectively. we confirmed the cleavage site of these precursors after n731 for brka and after n393 for tracheal colonization factor. associated with the 32- ... | 1999 | 10079522 |
| simultaneous amplification of bordetella repeated insertion sequences and toxin promoter region gene by polymerase chain reaction. | a polymerase chain reaction was devised to simultaneously detect repeated insertion sequences and the pertussis toxin promoter gene for the diagnostic identification of bordetella pertussis, b. parapertussis, and b. bronchiseptica. the sensitivity of this method was sufficient to detect one b. pertussis organism using the following cycles and temperatures: 95 degrees c for 15 min, followed by 32 amplification cycles (1 min at 95 degrees c, 1 min at 66 degrees c, 1 min at 72 degrees c), and final ... | 1999 | 10084330 |
| the alternative sigma factor, sigmae, is critically important for the virulence of salmonella typhimurium. | in escherichia coli, extracytoplasmic stress is partially controlled by the alternative sigma factor, rpoe (sigmae). in response to environmental stress or alteration in the protein content of the cell envelope, sigmae upregulates the expression of a number of genes, including htra. it has been shown that htra is required for intramacrophage survival and virulence in salmonella typhimurium. to investigate whether sigmae-regulated genes other than htra are involved in salmonella virulence, we ina ... | 1999 | 10084987 |
| in vivo expression and immunoadjuvancy of a mutant of heat-labile enterotoxin of escherichia coli in vaccine and vector strains of vibrio cholerae. | vibrio cholerae secretes cholera toxin (ct) and the closely related heat-labile enterotoxin (lt) of escherichia coli, the latter when expressed in v. cholerae. both toxins are also potent immunoadjuvants. mutant lt molecules that retain immunoadjuvant properties while possessing markedly diminished enterotoxic activities when expressed by e. coli have been developed. one such mutant lt molecule has the substitution of a glycine residue for arginine-192 [lt(r192g)]. live attenuated strains of v. ... | 1999 | 10085006 |
| oligomerization of anthrax toxin protective antigen and binding of lethal factor during endocytic uptake into mammalian cells. | the protective antigen (pa) protein of anthrax toxin binds to a cellular receptor and is cleaved by cell surface furin to produce a 63-kda fragment (pa63). the receptor-bound pa63 oligomerizes to a heptamer and acts to translocate the catalytic moieties of the toxin, lethal factor (lf) and edema factor (ef), from endosomes to the cytosol. in this report, we used nondenaturing gel electrophoresis to show that each pa63 subunit in the heptamer can bind one lf molecule. studies using pa immobilized ... | 1999 | 10085027 |
| identification of a receptor-binding region within domain 4 of the protective antigen component of anthrax toxin. | anthrax toxin from bacillus anthracis is a three-component toxin consisting of lethal factor (lf), edema factor (ef), and protective antigen (pa). lf and ef are the catalytic components of the toxin, whereas pa is the receptor-binding component. to identify residues of pa that are involved in interaction with the cellular receptor, two solvent-exposed loops of domain 4 of pa (amino acids [aa] 679 to 693 and 704 to 723) were mutagenized, and the altered proteins purified and tested for toxicity i ... | 1999 | 10085028 |
| an epidemic of a pertussis-like illness caused by chlamydia pneumoniae. | between june and july, 1994, we encountered an epidemic of a pertussis-like illness in adolescents in a junior high school located in a rural area of japan. the purposes of this study were to record the clinical manifestations and to identify an etiology. | 1999 | 10093951 |
| the major phase-variable outer membrane protein of escherichia coli structurally resembles the immunoglobulin a1 protease class of exported protein and is regulated by a novel mechanism involving dam and oxyr. | here we report the characterization of an escherichia coli gene (agn43) which encodes the principal phase-variable outer membrane protein termed antigen 43 (ag43). the agn43 gene encodes a precursor protein of 107 kda containing a 52-amino-acid signal sequence. posttranslational processing generates an alpha43 subunit (predicted mr of 49,789) and a c-terminal domain (beta43) with features typical of a bacterial integral outer membrane protein (predicted mr of 51, 642). secondary structure analys ... | 1999 | 10094691 |
| effect of aspergillus terreus mycotoxins on nitric oxide synthase activity in human erythroid k-562 cells. | because several stimuli of microbial origin enhance the activity of nitric oxide synthase (nos) in human cells of the myeloid lineage, we decided to investigate whether cellular damage induced by aspergillus terreus mycotoxins could be associated with an increase in nos activity. a pool of mycotoxins rather than individual toxins was tested so that the natural conditions could be mimicked. in the present study, we report that a crude extract of a. terreus induces cellular damage and increases no ... | 1999 | 10191507 |
| cell-specific coupling of pge2 to different transduction pathways in arginine vasopressin- and glucagon-sensitive segments of the rat renal tubule. | 1. the aim of the present study was to investigate the transduction pathways elicited by prostaglandin e2 (pge2) to inhibit hormone-stimulated adenosine 3':5'-cyclic monophosphate (cyclic amp) accumulation in the outer medullary collecting duct (omcd) and medullary thick ascending limb (mtal) microdissected from the rat nephron. 2. in the omcd, 0.3 microm pge2 and low concentrations of ca2+ ionophores (10 nm ionomycin or 50 nm a23187) inhibited by about 50% a same pool of arginine vasopressin (a ... | 1999 | 10193786 |
| the conserved lysine 860 in the additional fatty-acylation site of bordetella pertussis adenylate cyclase is crucial for toxin function independently of its acylation status. | the bordetella pertussis rtx (repeat in toxin family protein) adenylate cyclase toxin-hemolysin (act) acquires biological activity upon a single amide-linked palmitoylation of the epsilon-amino group of lysine 983 (lys983) by the accessory fatty-acyltransferase cyac. however, an additional conserved rtx acylation site can be identified in act at lysine 860 (lys860), and this residue becomes palmitoylated when recombinant act (r-ec-act) is produced together with cyac in escherichia coli k12. we h ... | 1999 | 10196151 |
| the ctra response regulator mediates temporal control of gene expression during the caulobacter cell cycle. | in its role as a global response regulator, ctra controls the transcription of a diverse group of genes at different times in the caulobacter crescentus cell cycle. to understand the differential regulation of ctra-controlled genes, we compared the expression of two of these genes, the fliq flagellar gene and the ccrm dna methyltransferase gene. despite their similar promoter architecture, these genes are transcribed at different times in the cell cycle. pfliq is activated earlier than pccrm. ph ... | 1999 | 10198005 |
| cloning and characterization of two bistructural s-layer-rtx proteins from campylobacter rectus. | campylobacter rectus is an important periodontal pathogen in humans. a surface-layer (s-layer) protein and a cytotoxic activity have been characterized and are thought to be its major virulence factors. the cytotoxic activity was suggested to be due to a pore-forming protein toxin belonging to the rtx (repeats in the structural toxins) family. in the present work, two closely related genes, csxa and csxb (for c. rectus s-layer and rtx protein) were cloned from c. rectus and characterized. the cs ... | 1999 | 10198015 |
| bordetella pertussis waaa encodes a monofunctional 2-keto-3-deoxy-d-manno-octulosonic acid transferase that can complement an escherichia coli waaa mutation. | bordetella pertussis lipopolysaccharide (lps) contains a single 2-keto-3-deoxy-d-manno-octulosonic acid (kdo) residue, whereas lps from escherichia coli contains at least two. here we report that b. pertussis waaa encodes an enzyme capable of transferring only a single kdo during the biosynthesis of lps and that this activity is sufficient to complement an e. coli waaa mutation. | 1999 | 10198035 |
| therapy of murine tumors with recombinant bordetella pertussis adenylate cyclase carrying a cytotoxic t cell epitope. | bordetella pertussis secretes an invasive adenylate cyclase toxin, cyaa, that is able to deliver its n-terminal catalytic domain into the cytosol of eukaryotic target cells directly through the cytoplasmic membrane. we have shown previously that recombinant cyaa can be used to deliver viral cd8+ t cell epitopes to the mhc-class i presentation pathway to trigger specific ctl responses in vivo. in the present study, we show that mice immunized with a detoxified but still invasive cyaa carrying a c ... | 1999 | 10201941 |
| comparative effects of a glucocorticosteroid, theophylline and the peptido-leukotriene-antagonist cgp 45715a on antigen-induced early and late phase airway response and inflammatory cell influx in sensitised guinea pigs. | a novel model of allergic early and late-phase reaction in the airways of conscious guinea pigs was developed and the effect of established and novel antiasthmatic drugs on peak of immediate response, late phase response and associated inflammatory cell influx investigated. guinea pigs were sensitised twice in adjuvant (50 mg/kg silica + 0.1 ml/kg bordetella pertussis). under cover of 10 mg/kg i.p. mepyramine guinea pigs exhibited still a pronounced immediate reaction. during a screening phase a ... | 1999 | 10206183 |
| microbial epitopes act as altered peptide ligands to prevent experimental autoimmune encephalomyelitis. | molecular mimicry refers to structural homologies between a self-protein and a microbial protein. a major epitope of myelin basic protein (mbp), p87-99 (vhffknivtprtp), induces experimental autoimmune encephalomyelitis (eae). vhffk contains the major residues for binding of this self-molecule to t cell receptor (tcr) and to the major histocompatibility complex. peptides from papilloma virus strains containing the motif vhffk induce eae. a peptide from human papilloma virus type 40 (hpv 40) conta ... | 1999 | 10209044 |
| mice immunization with gel electrophoresis-micropurified bacterial lipopolysaccharides. | some evidence on the possible use of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (sds-page) to elicit antibodies against smooth- or rough-type bacterial lipopolysaccharides (lps) is shown. gel-separated lps were negatively stained with zinc-imidazole to precisely localize the bands of interest under fully reversible conditions. then the bands of interest were excised and the resulting gel slices washed in a solution of a zinc-complexing agent (e.g., 100 mm edta), after which they w ... | 1999 | 10217152 |
| bordatella pertussis adenylate cyclase: a toxin with multiple talents. | bordetella pertussis secretes a calmodulin-activated adenylate cyclase toxin (cyaa) that is able to deliver its amino-terminal catalytic domain into the cytosol of eukaryotic cells. the novelty of the structural organization and conformational flexibility of the cyaa catalytic domain has opened up the way for exploiting this protein as a tool for several biological applications, including epitope delivery, protein targeting and characterization of protein-protein interactions. | 1999 | 10217833 |
| [prevalence of antibodies against tetanus, diphtheria and bordetella pertussis in health care professionals]. | the aim of the present study was to determine the prevalence of antibodies versus tetanus, diphtheria and bordetella pertussis in a population of health care personnel. | 1999 | 10217849 |
| identification of immunodominant epitopes in the filamentous hemagglutinin of bordetella pertussis. | the filamentous hemagglutinin (fha) of bordetella pertussis is a principal adhesin, which plays a key role in the colonization of the upper respiratory tract. fha is also a protective antigen, which has been incorporated in the new generation of acellular vaccines against whooping cough. the protein is synthesized as a large 367-kda precursor, which is then processed into a 220-kda secreted polypeptide. to optimize the use of this protein for vaccine purposes it would be helpful to define the re ... | 1999 | 10219596 |
| [effect of antibiotics and antibody on phagocytic bactericidal activity of polymorphonuclear neutrophils of bordetella pertussis]. | the phagocytic bactericidal activity of the polymononucler neutrophils (pmns) that were collected from healthy volunteer with and without antibody against bordetella pertussis was investigated. furthermore, these activity against b. pertussis under observing penicillins or macrolides antibiotics was investigated. although no efficacy to b. pertussis strain by the pmns in serum without antibody, but the viable cells of b. pertussis decreased to 1/1,000 1 hr after incubation and was not detected a ... | 1999 | 10222670 |
| cell-mediated immune responses to antigens of bordetella pertussis and protection against pertussis in school children. | increasing evidence suggests that cell-mediated immunity (cmi) is involved in immune response against bordetella pertussis. however, there are practically no studies evaluating the significance of pertussis-specific cmi in relation to protection against clinical pertussis. | 1999 | 10223692 |
| adjuvant and protective properties of native and recombinant bordetella pertussis adenylate cyclase toxin preparations in mice. | bordetella pertussis produces a cell-invasive adenylate cyclase toxin which is synthesised from the cyaa gene as an inactive protoxin that is post-translationally activated by the product of the cyac gene. purified active and inactive cyaa proteins were prepared from b. pertussis or from recombinant escherichia coli expressing both cyaa and cyac genes or the cyaa gene alone. respectively. in addition, a hybrid toxin (hyb2) in which an internal region of cyaa had been replaced with the analogous ... | 1999 | 10225286 |
| epitope mapping of monoclonal antibodies against bordetella pertussis adenylate cyclase toxin. | adenylate cyclase (ac) toxin from bordetella pertussis is a 177-kda repeats-in-toxin (rtx) family protein that consists of four principal domains; the catalytic domain, the hydrophobic domain, the glycine/aspartate-rich repeat domain, and the secretion signal domain. epitope mapping of 12 monoclonal antibodies (mabs) directed against ac toxin was conducted to identify regions important for the functional activities of this toxin. a previously developed panel of in-frame deletion mutants of ac to ... | 1999 | 10225859 |
| immunogenicity of a salmonella typhimurium aroa arod vaccine expressing a nontoxic domain of clostridium difficile toxin a. | the c-terminal repeat domain of clostridium difficile toxin a harbors toxin-neutralizing epitopes and is considered to be a candidate component of a vaccine against c. difficile-associated disease (cdad). fourteen of the 38 c-terminal toxin a repeats (14cdta) were cloned into ptech-1 in frame with the immunogenic fragment c of tetanus toxin (tetc) to generate plasmid p56tetc. expression of the tetc-14cdta fusion protein was driven from the anaerobically inducible nirb promoter within attenuated ... | 1999 | 10225867 |
| inverse relationship between severity of experimental pyelonephritis and nitric oxide production in c3h/hej mice. | the contribution of nitric oxide to host resistance to experimental pyelonephritis is not well understood. we examined whether the inhibition of nitric oxide synthesis alters the sensitivity of lipopolysaccharide (lps) responder (c3h/hen) and nonresponder (c3h/hej) mice to experimental escherichia coli pyelonephritis. c3h/hej and c3h/hen mice were implanted subcutaneously with minipumps containing an inhibitor of nitric oxide, ng-nitro-l-arginine methyl ester (l-name), or a corresponding vehicle ... | 1999 | 10225904 |
| cellular immune responses to neisseria meningitidis in children. | there is an urgent need for effective vaccines against serogroup b neisseria meningitidis. current experimental vaccines based on the outer membrane proteins (omps) of this organism provide a measure of protection in older children but have been ineffective in infants. we postulated that the inability of omp vaccines to protect infants might be due to age-dependent defects in cellular immunity. we measured proliferation and in vitro production of gamma interferon (ifn-gamma), tumor necrosis fact ... | 1999 | 10225908 |
| single-dose mucosal immunization with biodegradable microparticles containing a schistosoma mansoni antigen. | the purpose of this work was to assess the immunogenicity of a single nasal or oral administration of recombinant 28-kda glutathione s-transferase of schistosoma mansoni (rsm28gst) entrapped by poly(lactide-co-glycolide) (plg)- or polycaprolactone (pcl)-biodegradable microparticles. whatever the polymer and the route of administration used, the equivalent of 100 microg of entrapped rsm28gst induced a long-lasting and stable antigen-specific serum antibody response, with a peak at 9 to 10 weeks f ... | 1999 | 10225935 |
| protein-kinase-specific inhibitors block langerhans' cell migration by inhibiting interleukin-1alpha release. | previous studies have shown that depletion of langerhans' cells (lc) from murine epidermis by the superantigen, staphylococcal enterotoxin a (sea) involves interleukin-1alpha (il-1alpha) and is inhibitable by agents that block g-protein-associated kinases. the purpose of this study was to determine whether specific kinase inhibitors block lc depletion by inhibiting il-1alpha release and to ascertain whether lc depletion by sea involves cell migration. these goals were addressed by measuring the ... | 1999 | 10233700 |
| identification of genetic determinants for the hemolytic activity of streptococcus agalactiae by iss1 transposition. | streptococcus agalactiae is a poorly transformable bacterium and studies of molecular mechanisms are difficult due to the limitations of genetic tools. employing the novel pgh9:iss1 transposition vector we generated plasmid-based mutant libraries of s. agalactiae strains o90r and ac475 by random chromosomal integration. a screen for mutants with a nonhemolytic phenotype on sheep blood agar led to the identification of a genetic locus harboring several genes that are essential for the hemolytic f ... | 1999 | 10322024 |
| a novel campylobacter jejuni two-component regulatory system important for temperature-dependent growth and colonization. | campylobacter jejuni colonizes the intestines of domestic and wild animals and is a common cause of human diarrheal disease. we identified a two-component regulatory system, designated the racr-racs (reduced ability to colonize) system, that is involved in a temperature-dependent signalling pathway. a mutation of the response regulator gene racr reduced the organism's ability to colonize the chicken intestinal tract and resulted in temperature-dependent changes in its protein profile and growth ... | 1999 | 10322038 |
| phylogenetic analysis of ara+ and ara- burkholderia pseudomallei isolates and development of a multiplex pcr procedure for rapid discrimination between the two biotypes. | a burkholderia pseudomallei-like organism has recently been identified among some soil isolates of b. pseudomallei in an area with endemic melioidosis. this organism is almost identical to b. pseudomallei in terms of morphological and biochemical profiles, except that it differs in ability to assimilate l-arabinose. these ara+ isolates are also less virulent than the ara- isolates in animal models. in addition, clinical isolates of b. pseudomallei available to date are almost exclusively ara-. t ... | 1999 | 10325345 |
| new roles for rgs2, 5 and 8 on the ratio-dependent modulation of recombinant girk channels expressed in xenopus oocytes. | 1. the activation of g protein-regulated inward rectifying potassium (girk) channels is modulated by g protein-coupled receptors (gpcrs) via the g protein betagamma subunits and is accelerated by regulators of g protein signalling (rgs). in the present study we investigated the ratio dependence of receptor-mediated activation and deactivation and the influence of new members of the rgs protein family on girk currents by coexpressing the recombinant protein subunits in xenopus oocytes and further ... | 1999 | 10332086 |
| clinical manifestations of bordetella pertussis infection in immunized children and young adults. | the incidence and prevalence of pertussis in adults have increased in recent years. it has been shown that previously immunized adults and adolescents are the main sources of transmission of bordetella pertussis. the aim of this study was to describe the clinical presentation and the clinical course of pertussis in children and young adults who were immunized previously against b pertussis. | 1999 | 10334136 |
| glycosaminoglycan-binding microbial proteins in tissue adhesion and invasion: key events in microbial pathogenicity. | glycosaminoglycans such as heparin, heparan sulphate and dermatan sulphate, are distributed widely in the human body. several glycosaminoglycans form part of the extracellular matrix and heparan sulphate is expressed on all eukaryotic surfaces. the identification of specific binding to different glycosaminoglycan molecules by bacteria (e.g., helicobacter pylori, bordetella pertussis and chlamydia trachomatis), viruses (e.g., herpes simplex and dengue virus), and protozoa (e.g., plasmodium and le ... | 1999 | 10334589 |
| assessment of mucosal immune response in genitourinary tract using urine. | a novel method to assess mucosal immune response in the genitourinary mucosa after immunization with a mucosal vaccine has been developed. in this method, secretory iga antibody is measured by a highly sensitive enzyme immunoassay (immune-complex transfer enzyme immunoassay) using urine as a specimen. the urinary iga antibody response could be detected by the immune-complex transfer enzyme immunoassay. in contrast, a conventional enzyme immunoassay (enzyme-linked immunosorbent assay (elisa)) cou ... | 1999 | 10338195 |