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roles of frxa and rdxa nitroreductases of helicobacter pylori in susceptibility and resistance to metronidazole.the relative importance of the frxa and rdxa nitroreductase genes of helicobacter pylori in metronidazole (mtz) susceptibility and resistance has been controversial. jeong et al. (j. bacteriol. 182:5082--5090, 2000) had interpreted that mtz(s) h. pylori were of two types: type i, requiring only inactivation of rdxa to became resistant, and type ii, requiring inactivation of both rdxa and frxa to become resistant; frxa inactivation by itself was not sufficient to confer resistance. in contrast, k ...200111489869
molecular mimicry of host structures by lipooligosaccharides of neisseria meningitidis: characterization of sialylated and nonsialylated lacto-n-neotetraose (galbeta1-4glcnacbeta1-3galbeta1-4glc) structures in lipooligosaccharides using monoclonal antibodies and specific lectins.neisseria meningitidis lipooligosaccharides (loss) are classified into 12 immunotypes. most loss are heterogeneous in having a few components by sds-page analysis that differ antigenically and chemically. we have utilized a monoclonal antibody that recognizes lacto-n-neotetraose (lnnt) and the lectin, maackia amurensis leukoagglutinin (mal), which is specific for neunacalpha2-3galbeta1-4glcnac trisacchride sequence to characterize the 12 n. meningitidis loss. using the combination of elisa, sds- ...200114533820
caspase-3 activity and expression of bcl-2 family in human neutrophils by helicobacter pylori water-soluble proteins.persistent infiltration of neutrophils is an almost invariable feature of helicobacter pylori-infected gastric mucosa. a prolongation of neutrophil life-span could contribute to the pathogenesis of h. pylori infection. recently, we have demonstrated that h. pylori water extracts (hpwe) inhibited neutrophil apoptosis. to elucidate the regulation of intracellular apoptotic signals by hpwe, we examined the activity of caspase-8, -3 and expression of bcl-2 family in neutrophils.200111683923
[in vitro study of the biological activities and immunogenicity of recombinant adhesin of heliobacter pylori rhpaa].to evaluate the biological activities and immunogenicity of recombinant adhesin of helicobacter pylori rhpaa in vitro and the feasibility of its application in development of helicobacter pylori vaccine.200111798887
antimicrobial potential of probiotic lactic acid bacteria.antibacterial activity is an important characteristic of probiotics. a possible way to achieve this antibacterial activity is through the production of bacteriocins. this study shows that the commercial probiotic strains lactobacillus johnsonii la1 and lactobacillus casei yit 9029 produce bacteriocins. the nature of the antimicrobial compound could be derived from its behaviour: a narrow inhibitory spectrum (only active against closely related strains), loss of activity when treated with protein ...200115954651
motility, chemotaxis, and flagellafor many pathogenic bacteria, flagellum-dependent motility and chemotaxis are crucial factors in the process of colonization of the host organism and establishment of a successful infection (reviewed in references 36 and 39). the flagella of helicobacter pylori have been extensively studied, and convincing evidence is available demonstrating the key role of these organelles in the colonization of the human gastric mucosa by this fastidious pathogen. experiments with gnotobiotic piglets have esta ...200121290725
regulation of urease for acid habitationh. pylori shows a remarkable acid-resistance response to the gastric environment by a specialized means of utilizing an intracellular, neutral ph optimum urease. within the urease gene cluster it has a gene encoding an acid-activated urea channel, urei. instead of an acidic ph optimum urease suitable only for passage through the stomach, it has a neutral ph optimum urease that allows the cytoplasm to remain relatively neutral while the organism protects itself against acid by enhancing urea acce ...200121290728
enterohepatic helicobacter speciesmost of the members of the genus helicobacter do not normally colonize the gastric mucosa, but instead thrive in the mucosal surfaces of the intestinal tract and/or the liver of humans, other mammals, and birds. these enterohepatic helicobacter species have features of ultrastructure and physiology in common with helicobacter pylori and the other gastric helicobacter species, and have been the subject of several recent ...200121290746
[effect of human serum on the growth of helicobacter pylori].to investigate whether sheep blood could be replaced with human serum or fetal calf serum for helicobacter pylori(hp) culture, hp was inoculated onto the culture plates containing 7% of sheep blood, human serum, or fetal calf serum respectively. the colonies were counted after 5 days of culture. similar culture results were obtained in the plates containing sheep blood, human serum, or fetal calf serum respectively. no effect of anti-hp-igg antibody in human serum on the growth of hp was found ( ...200012206006
[the prevalence of helicobacter pylori infection in gastric cancer and gastric stump cancer].in 1994, the international agency for research in cancer recognized helicobacter pylori (hp) as "a definitive cause of human cancer". the present study aimed at determining the prevalence of hp infection in the gastric cancer developed on the background of a disordered stomach as compared with gastric stump cancer. the prevalence of hp infection was a twice higher in the patients with gastric cancer than in those with gastric stump cancer, and in both cases much lower than that reported in the l ...200012089925
relation of helicobacter pylori to mucins and mucous cells in human stomach. 200012167291
helicobacter pylori and non-steroidal anti-inflammatory drugs. 200011245298
mechanism underlying post-infectious motility disorders. 200011245301
[discussions on problems in chemotherapy at the vii national russian congress "man and drug"]. 200011212496
does eradication of helicobacter pylori reverse atrophic gastritis or intestinal metaplasia? data from japan.in japan, more reports showing improvement of atrophy or im after eradication have appeared than reports showing no change. many authors take biopsy specimens from the lesser and greater curvatures of the antrum and body and incisura angularis and make a histologic assessment using the standardized updated sydney system. sampling errors should be taken into account, however. interobserver agreement is poor in grading of atrophy. apart from these problems, it seems almost certain that some patien ...200011190067
[genomic structure of helicobacter pylori and its pathogenecity]. 200011155709
in search of immunogenic helicobacter pylori proteins by screening of expression library.prevention of helicobacter pylori infection may help to control related gastritis, peptic ulcer and cancer. of the possible preventive measures, immunization was successfully employed in various animal studies. however, no immunization protocol has been accepted for humans. a better characterization of the immune response against the pathogen may be required before a human vaccine is developed.200010671770
structure of lamina propria lymphoid follicles and associated epithelium in the gastric mucosa during helicobacter pylori infection in ulcer-bearing mongolian gerbils.to develop a gerbil model of helicobacter pylori-induced chronic active gastritis comparable in severity to human lesions, we made acetic acid-induced ulcer in the anterior antral wall and concurrently challenged 1 x 10(8) colony-forming units bacteria per os. at 30 and 60 days after inoculation, the number of viable bacteria colonizing on the surface epithelium of the gastric mucosa was larger in ulcer-bearing animals compared to non-bearing ones. furthermore, in the former animals, neutrophil ...200011085204
serologic and histopathologic study of chlamydia pneumoniae infection in atherosclerosis: a possible pathogenetic mechanism of atherosclerosis induced by chlamydia pneumoniae.chronic infection and inflammation have recently been implicated as important etiologic agents for atherosclerosis in general and, in particular, ischemic heart disease. several agents have been suggested as possible candidates for the chronic inflammation including cytomegalovirus, helicobacter pylori and chlamydia pneumoniae. we hypothesized that a vascular infection with c. pneumoniae may induce a chronic inflammatory reaction in the host vascular tissue and activated inflammatory cells may e ...200010957885
[multilocular fixed drug reaction simulating intertrigo in a diabetic patient].a 57-year-old man with diabetes and hypertension was treated with amoxycillin, clarithromycin and pantoprazole for a gastric ulcer positive for helicobacter pylori. on the second treatment day he developed inguinal pruritus with erythema. he presented at out-patient clinic on the 5th day suspected of having candida intertrigo. he had bright red, relatively well-circumscribed erythema, most marked at the edges, mainly over the inguinal region and the inside of the thigh. there were no other sympt ...200011098237
expression of human telomerase catalytic subunit gene in cancerous and precancerous gastric conditions.telomerase activity is thought to be necessary for cellular immortality and carcinogenesis. the mrna that encodes the telomerase catalytic subunit (htert) has recently been identified, and expression of htert mrna is thought to regulate activation of telomerase. to determine at what stage of carcinogenesis cells begin to express htert, we analysed htert mrna expression in gastric carcinoma and precancerous conditions, focusing on chronic gastritis with or without intestinal metaplasia.200010937679
detection of chlamydia pneumoniae and helicobacter pylori dna in human atherosclerotic plaques by pcr.chlamydia pneumoniae and helicobacter pylori can cause persistent infections of the respiratory and gastrointestinal tract, respectively. it has been suggested that persistent infection of arteries with these bacteria can contribute to the development of atherosclerosis. the aims of this study were to determine the presence of c. pneumoniae and h. pylori dna in atherosclerotic plaque samples by pcr and to evaluate the correlation between clinical status and dna positivity of these bacteria. eigh ...200011101572
an assessment of the long-term preservation of the dna of a bacterial pathogen in ethanol-preserved archival material.to examine the potential for dna recovery from spirit-preserved medical material, a set of specimens from the hunterian collection of the royal college of surgeons was investigated. using a range of dna extraction techniques and the pcr, no replicable positive amplifications were made from this material of either human or helicobacter dna. experiments with modern stomach biopsies of h. pylori-positive patients suggest that the bacterial dna is typically present in a much lower concentration (10( ...200011113876
a high molecular mass constituent of cranberry juice inhibits helicobacter pylori adhesion to human gastric mucus.because previous studies have shown that a high molecular mass constituent of cranberry juice inhibited adhesion of escherichia coli to epithelial cells and coaggregation of oral bacteria, we have examined its effect on the adhesion of helicobacter pylori to immobilized human mucus and to erythrocytes. we employed three strains of h. pylori all of which bound to the mucus and agglutinated human erythrocytes via a sialic acid-specific adhesin. the results showed that a high molecular mass constit ...200011118911
up-regulation of the il-12 receptor beta 2 chain in crohn's disease.crohn' s disease (cd) is a chronic intestinal inflammatory disorder characterized by aberrant mucosal th1 cell activation and production of il-12, the major th1-driving factor. the t cell response to il-12 is dependent on the expression of a specific receptor composed of two subunits, termed il-12rbeta1 and il-12rbeta2. the content of il-12rbeta2, as measured at the mrna level, is crucial in regulating th1 differentiation. in this study we therefore investigated il-12rbeta2 rna transcripts in cd ...200011120856
characteristics of helicobacter pylori attachment to human primary antral epithelial cells.conventional cell lines are commonly used to study infection characteristics of the human gastric pathogen helicobacter pylori. we sought to investigate bacterial attachment to human antral primary epithelial cells, a cell model that more closely resembles the human stomach than transformed cell lines. primary cells were infected for 24 and 48 h with h. pylori. morphological appearance of both the pathogen and the cells as well as features of colonization, attachment and internalization were eva ...200011137040
identification of helicobacter pylori and other helicobacter species by pcr, hybridization, and partial dna sequencing in human liver samples from patients with primary sclerosing cholangitis or primary biliary cirrhosis.helicobacter pylori was identified in human liver tissue by pcr, hybridization, and partial dna sequencing. liver biopsies were obtained from patients with primary sclerosing cholangitis (n = 12), primary biliary cirrhosis (n = 12), and noncholestatic liver cirrhosis (n = 13) and (as controls) normal livers (n = 10). pcr analyses were carried out using primers for the helicobacter genus, helicobacter pylori (the gene encoding a species-specific 26-kda protein and the 16s rrna), helicobacter bili ...200010698999
purification of surface-associated urease from helicobacter pylori.helicobacter pylori colonizes the human gastric mucosa and produces large amounts of urease. the enzyme was extracted from the bacteria by distilled water and purified by gel-permeation (sephacryl s-300), anion-exchange chromatography (mono q) and a second gel-permeation (superdex 200). urease enzyme activity was detected with a spectrophotometic assay based on phenol red. the optimal ph for anion-exchange was 6.9. the recovery of urease was 55-75%, purity 93-98% and the overall protein recovery ...200010681057
effect of helicobacter pylori on polymorphonuclear leukocyte migration across polarized t84 epithelial cell monolayers: role of vacuolating toxin vaca and cag pathogenicity island.helicobacter pylori infection can induce polymorphonuclear leukocyte (pmnl) infiltration of the gastric mucosa, which characterizes acute chronic gastritis. the mechanisms underlying this process are poorly documented. the lack of an in vitro model has considerably impaired the study of transepithelial migration of pmnl induced by h. pylori. in the present work, we used confluent polarized monolayers of the human intestinal cell line t84 grown on permeable filters to analyze the epithelial pmnl ...200010948148
structure of an atypical o-antigen polysaccharide of helicobacter pylori containing a novel monosaccharide 3-c-methyl-d-mannose.lipopolysaccharides (lps) were isolated by hot phenol-water extraction from danish helicobacter pylori strains d1, d3, and d6, which were nontypeable using a variety of anti-lewis and anti-blood-group monoclonal antibodies. an atypical o-chain polysaccharide (ps) was liberated from the lps of the three strains by acid under mild conditions and found to contain d-rhamnose (d-rha), l-rhamnose (l-rha), and a branched sugar, 3-c-methyl-d-mannose (d-man3cme). the last sugar, which has not hitherto be ...200010769132
expression of secretory group iia phospholipase a(2) in relation to the presence of microbial agents, macrophage infiltrates, and transcripts of proinflammatory cytokines in human aortic tissues.recent seroepidemiological and immunohistochemical studies have demonstrated an association between microbial infections and atherosclerosis. however, the mechanisms underlying this association are widely unknown. in the present study, arterial specimens obtained at autopsy after sudden death were analyzed concerning (1) the presence of chlamydia pneumoniae, cytomegalovirus, herpes simplex virus, and helicobacter pylori; (2) the expression of secretory group iia phospholipase a(2) (spla(2)-iia) ...200010712401
unique mechanism of helicobacter pylori for colonizing the gastric mucus.helicobacter pylori is a human gastric pathogen causing chronic infection. urease and motility using flagella are essential factors for its colonization. urease of h. pylori exists both on the surface and in the cytoplasm, and is involved in neutralizing gastric acid and in chemotactic motility. h. pylori senses the concentration gradients of urea in the gastric mucus layer, then moves toward the epithelial surface by chemotactic movement. the energy source for the flagella movement is the proto ...200010717541
helicobacter pylori. one bacterium and a broad spectrum of human disease! an overview.since the historical rediscovery of gastric spiral helicobacter pylori in the gastric mucosa of patients with chronic gastritis by warren and marshall in 1983, peptic ulcer disease has been largely viewed as being of infectious aetiology. indeed, there is a strong association between the presence of h. pylori and chronic active gastritis in histology. the bacterium can be isolated in not less than 70% of gastric and in over 90% of duodenal ulcer patients. eradication of the organism has been ass ...200010791696
helicobacter pylori entry into human gastric epithelial cells: a potential determinant of virulence, persistence, and treatment failures.intracellular location of helicobacter pylori in human gastric epithelial cells has been observed in biopsies. whether this reflects an ability to invade host cells and establish an intracellular niche remains to be determined.200010971679
characterization of a culture method to recover helicobacter pylori from the feces of infected patients.helicobacter pylori is difficult to culture from stool. multiple efforts from multiple laboratories have been unsuccessful, and the optimal conditions to recover h. pylori from stool are still not known. recovery of h. pylori from feces of infected individuals is important for the performance of molecular epidemiological investigations, especially in children, where their symptoms do not warrant endoscopy to recover the organism.200010971682
innate immunity and the normal microflora.this paper discusses the following ten subtitles with the contents indicated. 1. to meet a microbe: discusses the four alternatives in host-microbe interactions. 2. receptors and signal transduction giving gene activation: discusses the lipopolysaccharide receptor and the limitations of cell cultures versus use of live animals. 3. effector molecules--antimicrobial peptides with and without cysteines. a data base exists with over 500 sequences. this paper gives a general overview of five classes ...200010719663
a new mechanism for anti-inflammatory actions of proton pump inhibitors--inhibitory effects on neutrophil-endothelial cell interactions.neutrophil-endothelial cell interactions mediated by adhesion molecules may be involved in gastric mucosal inflammation associated with helicobacter pylori or nonsteroidal anti-inflammatory drugs.200010807407
[helicobacter pylori and coronary heart diseases--hypotheses and facts].in 1994 mendall et al. (9) have suggested that there might be a correlation between helicobacter pylori (hp) infection and coronary heart disease (chd), mediated by a chronic low-grade acute phase reaction with mildly raised serum or plasma concentrations of c-reactive protein and fibrinogen. according to this hypothesis, a gastric hp colonization might be an additional risk factor for chd. in the meantime, 35 studies have examined whether hp seropositivity is associated with chd occurrence. how ...200010820865
biotransformation of glycyrrhizin by human intestinal bacteria and its relation to biological activities.the relationship between the metabolites of glycyrrhizin (18beta-glycyrrhetinic acid-3-o-beta-d-glucuronopyranosyl-(1-->2)-beta-d-glucuronide, gl) and their biological activities was investigated. by human intestinal microflora, gl was metabolized to 18beta-glycyrrhetinic acid (ga) as a main product and to 18beta-glycyrrhetinic acid-3-o-beta-d-glucuronide (gamg) as a minor product. the former reaction was catalyzed by eubacterium l-8 and the latter was by streptococcus lj-22. among gl and its me ...200010836746
bcl10 gene mutation in lymphoma.bcl10 is directly involved in t(1;14)(p22;q32) of mucosa-associated lymphoid tissue (malt) lymphoma. wild-type bcl10 promoted apoptosis and suppressed malignant transformation in vitro, whereas truncated mutants lost the pro-apoptotic activity and exhibited gain of function enhancement of transformation. we studied 220 lymphomas for genomic bcl10 mutation by polymerase chain reaction-single-strand conformational polymorphism and dna sequencing. nineteen mutations were found in 13 lymphoma specim ...200010845924
anti-adhesive activity of sulphated exopolysaccharides of microalgae on attachment of red sore disease-associated bacteria and helicobacter pylori to tissue culture cells.because of the affinity of certain bacterial species for sulphated glycoconjugates exposed on the epithelial cells of susceptible hosts, we hypothesized that sulphated exopolysaccharides of microalgae can be used in anti-adhesive therapies against bacterial infections, both in cold- and warm-blooded animals. in this study we found that adhesion of the human pathogen helicobacter pylori to the hela s3 cell line, and adhesion of the fish pathogens vibrio campbellii, v. ordalii, streptococcus sapro ...200010849279
apoptotic depletion of infiltrating mucosal lymphocytes associated with fas ligand expression by helicobacter pylori-infected gastric mucosal epithelium: human glandular stomach as a site of immune privilege.h. pylori infection almost invariably results in chronic gastritis, but only a proportion of patients develops severe destruction of epithelial glandular structure or peptic ulcer. to confirm the recent data obtained in testis and eye, showing that fas ligand is involved in the phenomenon of "immune privilege," expression of fas receptor and its ligand of the stomach was investigated in a panel of gastric biopsies obtained from patients h. pylori-positive (n = 42) and with h. pylori-negative (n ...200010759249
adherence of isogenic flagellum-negative mutants of helicobacter pylori and helicobacter mustelae to human and ferret gastric epithelial cells.isogenic flagellum-negative mutants of helicobacter pylori and helicobacter mustelae were screened for their ability to adhere to primary human and ferret gastric epithelial cells, respectively. we also evaluated the adherence of an h. pylori strain with a mutation in the flba gene, a homologue of the flbf/lcrd family of genes known to be involved in the regulation of h. pylori flagellar biosynthesis. h. pylori and h. mustelae mutants deficient in production of flaa or flab and mutants deficient ...200010858255
[decreasing prevalence of helicobacter pylori: a consequence of treatment of gastroduodenal ulcers].four patients with gastroduodenal ulcers in the absence of helicobacter pylori illustrate the decreasing prevalence of this microorganism. one was a 19-year-old boy with nausea, diarrhoea and weight loss caused by multiple gastroduodenal ulcers due to the zollinger-ellison syndrome. another was a 36-year-old man with abdominal discomfort caused by an ulcer due to crohn's disease. the other two cases concerned a 29-year-old man and a 68-year-old woman with relapsing ulcer disease and active bleed ...200010923145
h pylori colocalises with muc5ac in the human stomach.the bacterium helicobacter pylori is able to adhere to and to colonise the human gastric epithelium, yet the primary gene product responsible as a receptor for its adherence has not been identified.200010764701
role of activated protein c in helicobacter pylori-associated gastritis.the protein c (pc) pathway has recently been suggested to play a role in the regulation of the inflammatory response. to further extend the anti-inflammatory effect of activated pc (apc) in vivo, particularly its biological relevance to human disease, the activity of apc in the mucosa of patients with helicobacter pylori-associated gastritis and the effect of vacuolating cytotoxin (vaca), cytotoxin-associated antigen (caga), and h. pylori lipopolysaccharide (lps) on pc activation were evaluated. ...200010768983
deletion 7p in gastric malt lymphoma.deletion of the long arm of chromosome 7 has been related to loss of tumor suppressor genes which may constitute a primary step of carcinogenesis in many kinds of malignancies, including low-grade b-cell lymphoma. however, deletion of the short arm of chromosome 7, del(7p), in low-grade b-cell lymphoma has not been reported. here, we report a case of gastric malt lymphoma with the chromosome aberration del(7p) which progressed in spite of eradication of helicobactor pylori. deletion 7p may repre ...200010958947
helicobacter pylori urease binds to class ii mhc on gastric epithelial cells and induces their apoptosis.infection by helicobacter pylori leads to injury of the gastric epithelium and a cellular infiltrate that includes cd4+ t cells. h. pylori binds to class ii mhc molecules on gastric epithelial cells and induces their apoptosis. because urease is an abundant protein expressed by h. pylori, we examined whether it had the ability to bind class ii mhc and induce apoptosis in class ii mhc-bearing cells. flow cytometry revealed the binding of pe-conjugated urease to class ii mhc+ gastric epithelial ce ...200010925273
the human gastric colonizer helicobacter pylori: a challenge for host-parasite glycobiology.the gram-negative bacterium helicobacter pylori was first described in 1983 and currently represents one of the most active single research topics in biomedicine. it is specific for the human stomach and chronically colonizes a majority of the global population, which results in a symptom-free local inflammation. in 10-20% of carriers, gastroduodenal disease develops, including gastric or duodenal ulcer, and atrophic gastritis, which is a precondition to gastric cancer. a probable long coevoluti ...200010929002
morphologic differentiation of hl-60 cells is associated with appearance of rptpbeta and induction of helicobacter pylori vaca sensitivity.phorbol 12-myristate 13-acetate (pma) induces differentiation of human leukemic hl-60 cells into cells with macrophage-like characteristics and enhances the susceptibility of hl-60 cells to the helicobacter pylori vaca toxin (de bernard, m., moschioni., m., papini, e., telford, j. l., rappuoli, r., and montecucco, c. (1998) febs lett. 436, 218-222). we examined the mechanism by which hl-60 cells acquire sensitivity to vaca, in particular, looking for expression of rptpbeta, a vaca-binding protei ...200010809755
expression of cyclooxygenase-2 and nitrotyrosine in human gastric mucosa before and after helicobacter pylori eradication.to determine whether cure of helicobacter pylori infection influences the expression of cox-2 and nitrotyrosine in the distal stomach of humans, biopsy specimens were examined immunohistochemically. h. pylori infection was determined using a rapid urease test, culture and histology. positive staining of cox-2/nitrotyrosine in the epithelium was expressed as the percentage of stained cells to the total epithelial cells. there was a significant increase in cox-2/nitrotyrosine staining in h. pylori ...200011090259
significant increase in antigastric autoantibodies in a long-term follow-up study of h. pylori gastritis.in 30% of h. pylori-infected patients a certain type of antigastric autoantibodies, reacting against canalicular structures within human parietal cells, is detectable. furthermore, it has been shown that these autoantibodies are correlated with atrophy of the mucosa in the corpus. the aim of this study was to analyse the prevalence of these anticanalicular autoantibodies (acab) and their significance for development of gastric mucosa atrophy in a 12-year follow-up period. gastric biopsy specimen ...200010963378
helicobacter infection in dogs and cats: facts and fiction.the discovery of the spiral bacterium helicobacter pylori and its causative role in gastric disease in humans has brought a dramatic change to gastroenterology. although spiral bacteria have been known for more than a century to infect the stomachs of dogs and cats, recent research has been conducted mainly in the wake of interest in h. pylori. h. pylori has not been found in dogs and only very rarely in cats and zoonotic risk is minimal. a variety of other helicobacter spp. can infect the stoma ...200010772482
purification and characterization of cytochrome c-553 from helicobacter pylori.helicobacter pylori, a microaerophilic gram-negative spiral bacterium residing in the human stomach, contains a small size soluble cytochrome c. this cytochrome c was purified from the soluble fraction of h. pylori by conventional chromatographies involving octyl-cellulose and cm-toyopearl. its reduced form gave an alpha absorption band at 553 nm, and thus the cytochrome was named h. pylori cytochrome c-553. the cytochrome, giving a band below 10,000 da upon sds-page, was determined to have a ma ...200010965034
helicobacter pylori: an emerging infectious disease.helicobacter pylori is the most common chronic bacterial infection in the world, colonizing the stomachs of more than 50% of the human population. the discovery of this bacterium has changed the concept of care and management for peptic ulcer disease, mucosa-associated lymphomas, gastritis, and gastric carcinoma. although the mode of transmission is not definitively known, person-to-person contact is suspected. this article discusses h. pylori, the associated clinical syndromes and diseases, ris ...200010971934
quantitative analysis of helicobacter pylori infection in a mouse model.progress in elucidating the pathogenesis of helicobacter pylori gastric infection and in developing an h. pylori vaccine will be aided by an animal model in which h. pylori can be reliably detected. to validate the use of the mouse model of h. pylori infection, we determined the susceptibility of three inbred strains of mice (c57bl/6j, c57bl/10j and balb/c) to two vaca+/caga+ isolates of h. pylori (spm326 and m1.16) and determined the effectiveness of microbiological, histological and molecular ...200010986390
synthesis of mono- and di-fucosylated type i lewis blood group antigens by helicobacter pylori.the identification of helicobacter pylori isolates that expresses exclusively type i lewis antigens is necessary to determine the biosynthetic pathway of these antigens. fast-atom bombardment ms provides evidence that the h. pylori isolate ua1111 expresses predominantly leb, with h type i and lea in lesser amounts. cloning and expression of the h. pylori fucosyltransferases (fucts) allow comparisons with previously identified h. pylori enzymes and determination of the enzyme specificities. altho ...200010998067
matrix metalloproteinase expression in cultured human gastric wall fibroblasts--interactions with helicobacter pylori isolated from patients with ulcers.matrix metalloproteinases (mmps), enzymes capable of degrading collagens and other extracellular matrix components, have been implicated in gastric ulcer formation. however, the effect on mmp expression of helicobacter pylori, also implicated in these lesions, has not been studied to our knowledge.200010807424
the n-terminal 34 kda fragment of helicobacter pylori vacuolating cytotoxin targets mitochondria and induces cytochrome c release.the pathogenic bacterium helicobacter pylori produces the cytotoxin vaca, which is implicated in the genesis of gastric epithelial lesions. by transfect ing hep-2 cells with dnas encoding either the n-terminal (p34) or the c-terminal (p58) fragment of vaca, p34 was found localized specifically to mitochondria, whereas p58 was cytosolic. incubated in vitro with purified mitochondria, vaca and p34 but not p58 translocated into the mitochondria. microinjection of dnas encoding vaca-gfp and p34-gfp, ...200011101509
influence of smoking and helicobacter pylori on gastric phospholipids.smokers show higher rates of peptic ulcer disease (pud) than nonsmokers, probably due to detrimental effects on the gastric mucosa. surface-active phospholipids (spl) are believed to play a key part in gastric cytoprotection. the aim of this study was to determine the chronic effects of smoking on the gastric spl and to relate them to h. pylori (hp) -induced effects. gastric juice was aspirated in 52 patients, with normal findings at planned upper gastrointestinal endoscopy, and concentrations o ...200011007119
salivary agglutinin, which binds streptococcus mutans and helicobacter pylori, is the lung scavenger receptor cysteine-rich protein gp-340.salivary agglutinin is a high molecular mass component of human saliva that binds streptococcus mutans, an oral bacterium implicated in dental caries. to study its protein sequence, we isolated the agglutinin from human parotid saliva. after trypsin digestion, a portion was analyzed by matrix-assisted laser/desorption ionization time-of-flight mass spectrometry (maldi-tof ms), which gave the molecular mass of 14 unique peptides. the remainder of the digest was subjected to high performance liqui ...200011007786
cyp2c19 genotype status and intragastric ph during dosing with lansoprazole or rabeprazole.cyp2c19 has an important role in the catabolism of several proton pump inhibitors. however, the relative contribution of cyp2c19-mediated metabolism varies among the different proton pump inhibitors.200011012469
helicobacter pylori: clonal population structure and restricted transmission within families revealed by molecular typing.helicobacter pylori infects up to 50% of the human population worldwide. the infection occurs predominantly in childhood and persists for decades or a lifetime. h. pylori is believed to be transmitted from person to person. however, tremendous genetic diversity has been reported for these bacteria. in order to gain insight into the epidemiological basis of this phenomenon, we performed molecular typing of h. pylori isolates from different families. fifty-nine h. pylori isolates from 27 members o ...200011015377
[epidemiology, acquisition and transmission of helicobacter pylori].helicobacter pylori infection is a chronic infection essentially acquired during childhood. its prevalence in developed countries like france has decreased according to the year of birth all along the twentieth century, reflecting the progressive improvement of socio-economic and environmental conditions. the incidence of acquisition in adulthood is lower than 0.5% per year. in developing countries, the prevalence is still very high, even in early childhood. h. pylori is a strictly human bacteri ...200011019631
effects of helicobacter pylori in the stomach on neutrophil chemiluminescence in patients with gastric cancer.hypochlorous acid, which is one of the reactive oxgen species (ros) produced from human neutrophils, is converted to cytotoxic nh(2)cl after reaction with ammonia produced by urease in helicobacter pylori (hp), increasing gastric mucosal injury and with potential development to gastric cancer. we compared the effects of hp on the production of ros by human neutrophils between two groups-22 patients with gastric cancer and 16 patients without gastric cancer (control group), in whom hp was isolate ...200011038483
review article: helicobacter pylori: where are we and where are we going?this paper contains a personal view on what has been achieved in helicobacter pylori research and what the expectations might be for further developments. knowledge about the organism is already extensive. particularly intriguing are the differences in genetic make-up in the various geographical regions. sadly, detailed knowledge on how the organism spreads is still lacking. the clinical spectrum of the disease in man is largely known, but as h. pylori is disappearing worldwide, the relative fre ...200011050488
infections, atherosclerosis, and coronary heart disease.there is growing evidence that the immune response is involved in atherosclerosis. studies done over the past several years have shown an association between markers of inflammation and coronary atherosclerosis with an exacerbation of the inflammatory process during acute myocardial ischemia. overall, these data have greatly renewed interest in the infectious theory of atherosclerosis and coronary heart disease. search of bibliographic databases (from january 1991 through december 1999) and manu ...200010920505
helicobacter pylori cag pathogenicity island is associated with enhanced interleukin-8 expression in human gastric mucosa.in vitro studies showed that helicobacter pylori strains carrying the cag pathogenicity island are able to induce epithelial secretion of interleukin-8.200011057919
diet and duodenal ulcer.despite the fact that the main cause of duodenal ulcer incidence and recurrence is the helicobacter pylori bacterium, more than 80% of helicobacter pylori-infected people never develop an ulcer. diet may be one of the most important environmental factors contributing to duodenal ulcer.200011057920
helicobacter pylori infection: augmentation of telomerase activity in cancer and noncancerous tissues.telomerase adds hexameric repeats of 5'-ttaggg-3' to the ends of chromosomal dna (telomere) and has been implicated in cell immortalization and cellular senescence. the aim of this study was to measure quantitatively the telomerase activity and human telomerase rna component (htr) content in gastric cancer and to examine the relation between these values and histologic factors including helicobacter pylori as a risk factor for gastric cancer. telomerase activity was measured by a modified telome ...200011071470
cxc chemokines gro(alpha)/il-8 and ip-10/mig in helicobacter pylori gastritis.infection with helicobacter pylori causes chronic active gastritis, which is characterized by neutrophils infiltrating the gastric epithelial layer and the underlying lamina propria as well as by t, b lymphocytes and macrophages accumulating in the lamina propria. in this study, the chemokine profile responsible for the recruitment of these inflammatory cells is investigated. using both rna/rna in situ hybridization and immunohistochemistry, the expression of the neutrophil and/or lymphocyte-att ...200011091274
troxipide, a novel antiulcer compound, has inhibitory effects on human neutrophil migration and activation induced by various stimulants.neutrophils are considered to be involved in the pathogenesis of helicobacter pylori-associated gastroduodenal diseases on account of their potent biological functions as effector cells. troxipide, a new antiulcer compound used for patients with gastric ulcer or gastritis, has been shown to inhibit migration and activation of guinea pig neutrophils, but little is known about the pharmacological effects on human neutrophils.200011515628
chemistry and function of vegetable polyphenols with high molecular weights.structure and function of polypehnols with high molecular weights (tannins) were briefly reviewed to better understand the significance of polyphenol-rich foods and beverages. in a survey of bioactive ellagiannins with a macrocyclic structure and/or a gluconic acid core, some new oligomeric ellagitannins (eucarpanins and elaeagnatins) have been found in species of myrtaceae and elaeagnaceae, and their structures were elucidated by spectroscopic and chemical methods. cytotoxic activity against hu ...200011237170
resolution of syndrome x after eradication of virulent caga-positive helicobacter pylori.a 42-year-old man with chest pain was found to have st depression in leads v1 through v4. the coronary arteries appeared normal on angiography. positive results of ventricular pacing and acetylcholine test led to a diagnosis of syndrome x. other studies revealed gastritis due to caga-positive helicobacter pylori. classic therapy for angina did not resolve chest pain, but eradication of h. pylori led to disappearance of symptoms and negative test results.200011147468
[the association between helicobacter pylori and gastric neoplasia. epidemiologic evidence].helicobacter pylori (hp) causes chronic gastritis and, together with non-steroidal anti-inflammatory drugs, is considered the most frequent etiologic agent of peptic ulcer. since there are numerous epidemiologic and pathogenesis studies that demonstrate an association between infection by hp and gastric neoplasias, the world health organization declared, in 1994, hp infection a group 1 carcinogen (a definitive cause of human neoplasias, similar to tobacco). this article reviews the epidemiologic ...200011464618
ph-dependent protein profiles of helicobacter pylori analyzed by two-dimensional gels.helicobacter pylori survives transient exposure to extreme acid prior to adherence and growth on the gastric epithelium at neutral ph.200011179990
h. pylori in the pathogenesis of duodenal ulcer: interaction between duodenal acid load, bile, and h. pylori.helicobacter pylori (h. pylori) growth is inhibited by bile yet it can grow in the duodenal bulb and cause ulcer disease. the aim of this study was to test the effect of bile on h. pylori viability and growth and to determine whether acidification of bile reduces its inhibitory activity.200010638564
therapeutic immunization against helicobacter pylori infection in the absence of antibodies.helicobacter pylori is an important human pathogen. prophylactic immunization with bacterial antigen plus an adjuvant protects mice against challenge with live h. pylori. surprisingly, it was found that immunizations of mice already infected with helicobacter also influenced bacterial colonization. this concept of therapeutic immunization is a novel phenomenon. because h. pylori lives in the lumen of the stomach, it was initially hypothesized that the protective mechanism would involve induction ...200010651926
water extract of helicobacter pylori stimulates interleukin-8 secretion by a human gastric epithelial cell line (jr-st) through protein tyrosine phosphorylation.infection by helicobacter pylori induces cytokine production in gastric mucosal cells. production of interleukin-8 (il-8) is known to be markedly increased and is believed to play an important role in gastric mucosal inflammation. the aim of this study was to elucidate the effects of soluble factors of h. pylori on il-8 production in a gastric epithelial cell line, jr-st.200010764026
intestinal and pancreatic metaplasia at the esophagogastric junction in patients without barrett's esophagus.a distinctive type of columnar epithelium with intestinal metaplasia is considered diagnostic for barrett's esophagus. the neoplastic potential of pancreatic metaplasia at the esophagogastric junction is unknown. the aims of the present study were: 1) to characterize both forms of metaplasia at the esophagogastric junction, and to estimate their prevalence; 2) to investigate c-erbb-2 expression and k-ras mutations in pancreatic metaplasia; and 3) to study the relationship between metaplasia, inf ...200010710048
helicobacter pylori-antigen-binding fragments expressed on the filamentous m13 phage prevent bacterial growth.colonization of the human stomach by helicobacter pylori is associated with the development of gastritis, duodenal ulcer, mucosa-associated lymphoid tissue (malt) lymphoma, and gastric cancer. h. pylori-antigen-binding single-chain variable fragments (scfv) were derived from murine hybridomas producing monoclonal antibodies and expressed as a g3p-fusion protein on a filamentous m13 phage. the recombinant scfv-phage reacted specifically with a 30-kda monomeric protein of a h. pylori surface antig ...200010699497
helicobacter pylori possesses two chey response regulators and a histidine kinase sensor, chea, which are essential for chemotaxis and colonization of the gastric mucosa.infection of the mucous layer of the human stomach by helicobacter pylori requires the bacterium to be motile and presumably chemotactic. previous studies have shown that fully functional flagella are essential for motility and colonization, but the role of chemotaxis remains unclear. the two-component regulatory system chea/chey has been shown to play a major role in chemotaxis in other enteric bacteria. scrutiny of the 26695 genome sequence suggests that h. pylori has two chey response regulat ...200010722597
advances in gastroenterology and hepatology.this is a review of some of the most important growing points in the specialties of gastroenterology and hepatology. it does not aim to be completely comprehensive but to pick out major areas of importance to examination candidates and doctors without special experience in the field. topics covered include: upper gastrointestinal haemorrhage; barrett's oesophagus; carcinoma of the oesophagus; achalasia; helicobacter pylori; duodenal ulcer prevention; coeliac disease; dermatitis herpetiformis; cr ...200010824044
regression of colonic low grade b cell lymphoma of the mucosa associated lymphoid tissue type after eradication of helicobacter pylori.lymphoma of the mucosa associated lymphoid tissue (malt) arising in the stomach has been shown to be related to helicobacter pylori infection, and total regression of gastric lymphoma after successful eradication of h pylori has consistently been reported. malt-type lymphoma at other localisations, however, has to our knowledge not been linked to h pylori, and eradication of the bacteria has not been studied for management of such lymphomas. patient/method: a 67 year old man was diagnosed with m ...200010601069
helicobacter pylori induces apoptosis in gastric epithelial cells through inducible nitric oxide.gastric mucosal injury by helicobacter pylori has been suggested to be mediated by various cytokines induced by this organism. nitric oxide (no) is an important effector molecule involved in immune regulation and defence. to clarify the mechanisms by which h. pylori induces gastric mucosal cell injury, we examined whether h. pylori induces gastric epithelial death via no production.200010735541
helicobacter pylori activates the histidine decarboxylase promoter through a mitogen-activated protein kinase pathway independent of pathogenicity island-encoded virulence factors.helicobacter pylori infection of the gastric mucosa is accompanied by an activated histamine metabolism. histamine plays a central role in the regulation of gastric acid secretion and is involved in the pathogenesis of gastroduodenal ulcerations. histidine decarboxylase (hdc) is the rate-limiting enzyme for histamine production, and its activity is regulated through transcriptional mechanisms. the present study investigated the effect of h. pylori infection on the transcriptional activity of the ...200010652359
modulation of helicobacter pylori induced interleukin-8 synthesis in gastric epithelial cells mediated by cag pai encoded vird4 homologue.strains of helicobacter pylori carrying the virulence associated cag pathogenicity island (pai) induce gastric epithelial synthesis of the chemokine interleukin-8 (il-8), a neutrophil chemoattractant, and thereby a strong inflammatory response during chronic infection of the human gastric mucosa. previous mutational analyses have shown that many genes in the cag pai are needed to elicit il-8 synthesis in gastric epithelial cells, and also that some genes are not involved.199910655985
chemotaxis and motility of helicobacter pylori in a viscous environment.the chemotactic activity of helicobacter pylori is important for its colonization. h. pylori exhibited chemotactic responses to urea and potassium bicarbonate, which can be supplied from human gastric epithelium. the chemotactic activities of h. pylori in a fluid environment were higher on the urease-positive strain than on the isogenic urease-negative strain. in a viscous solution containing 3% polyvinylpyrrolidone, the urease-positive strain showed stimulated chemotactic activity, whereas the ...199910616760
potential relevance of agmatine as a virulence factor of helicobacter pylori.the polyamine agmatine is able to increase gastric acid secretion. therefore, we investigated whether helicobacter pylori is able to form and release agmatine in vitro and in the human stomach in vivo, and if so, whether a relationship exists among agmatine concentration in gastric juice, h. pylori infection, and gastroduodenal lesions. agmatine was determined by means of hplc. in the supernatant of h. pylori cultures, agmatine concentrations up to 1500 ng/ml (approximately 12 microm) were deter ...199910630488
inhibition by 16,16-dimethyl prostaglandin e2 of tumor necrosis factor-alpha and interleukin-1beta production and messenger rna expression in human monocytes stimulated by helicobacter pylori.we investigated the effects of 16,16-dimethyl prostaglandin e2 on the production of tumor necrosis factor-alpha and interleukin-1beta in human monocytes stimulated with helicobacter pylori. monocytes isolated from human peripheral blood were incubated for 24 hr with the extract of h. pylori diluted 1:100 to 1:100,000 by volume, a combination of the extract and 16,16-dimethyl prostaglandin e2, or a vehicle alone. the extract stimulated the production of tumor necrosis factor-alpha and interleukin ...199910630489
low prevalence of helicobacter pylori in individuals with htlv-i infection.the prevalence of helicobacter pylori in hiv-positive individuals is significantly lower than in hiv-negative controls. however, its prevalence in individuals infected with human t-cell leukaemia virus type i (htlv-i), another important member of the human retrovirus family, has not been previously investigated.199910755252
conservation, localization and expression of hopz, a protein involved in adhesion of helicobacter pylori.from a sarkosyl-insoluble outer membrane fraction prepared from the helicobacter pylori strain atcc 43504, 19 proteins could be sequenced n-terminally by edman degradation. oligonucleotides were deduced and used for screening of a genomic library. from the isolated genes, five code for different members of a h.pylori outer membrane protein (hop) family. among these, the hopz gene was characterized in more detail. it encodes a protein which was shown to be located at the bacterial surface by immu ...199910454640
endogenous nitric oxide in the regulation of gastric secretory and motor activity in humans.studies in animals have shown that nitric oxide (no) affects gastric secretory and motor functions. however, little information is available about the involvement of this substance in the control of gastric secretory and motor activity in man.199910594405
the development of functional foods: lessons from the gut.functional foods have resulted from the gradual recognition that healthy diets result from eating nutritious foods and from the identification of the mechanisms by which foods modulate metabolism and health. after initial successes with foods that reduce blood cholesterol level, probiotic bacteria and prebiotic carbohydrates have now also demonstrated added health benefits. as ingredients become more complex, the need to stabilize such ingredients in foods become increasingly important to the su ...199910557163
host determinants of helicobacter pylori infection and its clinical outcome.greater than one-half of the world's population harbors helicobacter pylori. the majority of infected individuals, however, remain asymptomatic, with only 10% to 20% developing diseases, including peptic ulcer disease, gastric cancer, and gastric mucosa-associated lymphoid tissue lymphoma. this article reviews host factors that may predispose an individual to both the acquisition of h. pylori infection and subsequent clinical outcome. individuals with specific blood group antigens and human leuk ...199910469193
cell damage and proliferation in human gastric mucosa infected by helicobacter pylori--a comparison before and after h pylori eradication in non-atrophic gastritis.helicobacter pylori (hp) is believed to be involved in the transition from normal gastric mucosa to atrophic gastritis and intestinal metaplasia. infection with the organism is one of the risk factors for development of intestinal-type gastric adenocarcinoma, possibly through altered cell turnover. medical eradication of hp is widely performed for the treatment of peptic ulcers and other upper gastrointestinal disorders. eradication of hp may affect altered cell turnover of the gastric mucosa ca ...199910667417
phenotypic changes of helicobacter pylori components during an experimental infection in mice.the bacterial pathogen helicobacter pylori is highly adapted to the human stomach and the clinical isolates show a high diversity which could be due to adaptative changes of the strains passing from one host to another. in order to study these variations, experimental infection of mice was developed and provided three out of the eleven tested strains able to infect c57bl/6 mice: the sydney strain which is known to be well adapted to mice and two freshly isolated strains from infected patients. m ...199910340709
[resuscitation from the viable but nonculturable state of helicobacter pylori].it is well known that the change of state from the culturable to not culturable on pathogenic organisms could easily occurred. these states of bacteria were so called viable but nonculturable (vnc). the coccoid form of h. pylori is seems to be in this state. the possibility of resuscitation of h. pylori was examined in vitro. the coccoid form bacteria was treated with ammonium sulfate and heat shock before culture, and cultured in brucella broth containing, sodium pyruvate, laked human erythrocy ...199910077897
a bacteriophage encoding a pathogenicity island, a type-iv pilus and a phage receptor in cholera bacteria.the virulence properties of many pathogenic bacteria are due to proteins encoded by large gene clusters called pathogenicity islands, which are found in a variety of human pathogens including escherichia coli, salmonella, shigella, yersinia, helicobacter pylori, vibrio cholerae, and animal and plant pathogens such as dichelobacter nodosus and pseudomonas syringae. although the presence of pathogenicity islands is a prerequisite for many bacterial diseases, little is known about their origins or ...199910360577
mitogenic autoantibodies in helicobacter pylori-associated stomach cancerogenesis.colonization of the bacterium helicobacter pylori of gastric mucosa plays an important role in stomach carcinogenesis, while the gastric mucosa and nearby lymphoid tissue are active sites of humoral immunity against both bacteria and tumor. in a broad study on the humoral immunity of stomach-cancer patients (5 patients with diffuse- and intestinal-type stomach carcinoma), we immortalized spleen cells by using human hybridoma technology and isolated 11 hybrid clones (9 igm, 1 igg and 1 iga) which ...199910188724
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