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the 26-kilodalton, ahpc homologue, of helicobacter pylori is also produced by other helicobacter species.the 26 kda protein, which is an alkyl hydroperoxide reductase (ahpc) homologue, has earlier been described as specific for helicobacter pylori. the aims of this study were to analyse whether this protein, or the corresponding gene, could be identified in other helicobacter species.200111328365
cox-2 inhibitors vs. nsaids in gastrointestinal damage and prevention.non-steroidal anti-inflammatory drugs (nsaids) inhibit production of protective gastric mucosal prostaglandins and also have a direct topical irritant effect. in some patients this results in dyspepsia and development of gastroduodenal erosions and ulceration. the risk of ulcer complications, such as bleeding, perforation and death is increased approximately 4-fold in nsaid users. patients at high risk of ulcer complications include the elderly, those taking anticoagulants, steroids and aspirin, ...200111336566
helicobacter pylori eradication therapy for high-grade mucosa-associated lymphoid tissue lymphomas of the stomach with analysis of p53 and k-ras alteration and microsatellite instability.recent studies have shown that 70-80% of low-grade mucosa-associated lymphoid tissue (malt) lymphomas regress in response to eradication of helicobacter pylori (h. pylori). however, there are no reports on whether gastric high-grade malt lymphomas regress after h. pylori eradication. we performed h. pylori eradication therapy in 4 patients with stage i, high-grade malt lymphoma after obtaining their informed consent. h. pylori infection was observed in all 4 patients. the patients were treated w ...200111351252
vaccine against helicobacter pylori?the burden of illness caused by helicobacter pylori is considerable, and there is little doubt that a therapeutic vaccine would be very useful. however, the merits of using a prophylactic vaccine to eradicate h. pylori from the human population are debatable in light of arguments that it may act as a beneficial commensal organism for many of its human hosts. with regard to the practical side of designing vaccines against h. pylori, animal models have shown us that both therapeutic and prophylact ...200111370768
pharmacodynamic effects and kinetic disposition of rabeprazole in relation to cyp2c19 genotypes.s-mephenytoin 4'-hydroxylase (cyp2c19) catalyses the metabolism of rabeprazole to some extent. based on the metabolic and pharmacokinetic differences among other proton pump inhibitors such as omeprazole, lansoprazole and pantoprazole, rabeprazole appears to be the least affected proton pump inhibitor by the cyp2c19-related genetic polymorphism.200111380317
database verification studies of swiss-prot and genbank.problem statement: we have studied the relationships among swiss-prot, trembl, and genbank with two goals. first is to determine whether users can reliably identify those proteins in swiss-prot whose functions were determined experimentally, as opposed to proteins whose functions were predicted computationally. if this information was present in reasonable quantities, it would allow researchers to decrease the propagation of incorrect function predictions during sequence annotation, and to assem ...200111395429
interleukin-1, interleukin-8, tumour necrosis factor alpha and interferon gamma stimulate dna synthesis but have no effect on apoptosis in small-intestinal cell lines.cytokines stimulate lymphocyte cell proliferation and affect cell division in several other cell types. helicobacter pylori-induced gastritis and coeliac disease are characterized by an increased cell proliferation in association with an increased production of proinflammatory cytokines, which could contribute to these cell kinetic changes. our aim is to examine in vitro whether cytokines usually present in the gastrointestinal mucosa affect dna synthesis and apoptosis in a rat and a human small ...200111396536
[mast cells in chronic gastritis of children].mast cell involvement in chronic gastritis in children was analyzed. 25 children with normal mucosa (controls), 20 children with chronic gastritis and 28 children with chronic gastritis and infected helicobacter pylori were included to the study. bioptic material from antrum and corpus of the stomach were stained with toluidine blue and anti-human mast cell tryptase to evaluate mast cell density. changes in mast cells number were also estimated in 7 children before and after successful eradicati ...200111398516
helicobacter pylori lipopolysaccharide-provoked injury to rat gastroduodenal microvasculature involves inducible nitric oxide synthase.the actions of a purified helicobacter pylori lipopolysaccharide (3 mg x kg(-1), i.v.) on rat gastric antral and duodenal microvascular integrity (determined as radiolabelled albumin leakage) and the expression of the inducible nitric oxide (no) synthase (inos; assessed by the citrulline assay) were investigated 4 h after challenge. significant increases of albumin leakage and expression of inos in both antral and duodenal tissues were observed following challenge. concurrent administration of t ...200111408040
transmission of helicobacter pylori: a role for food?helicobacter pylori colonizes and grows in human gastric epithelial tissue and mucus. its presence is associated with gastritis and there is substantial evidence that it causes peptic and duodenal ulcers and chronic gastritis. since 1994, h. pylori has been classified as carcinogenic to humans. in industrialized countries, as many as 50% of adults are infected with the pathogen, while in the developing world, prevalence values of about 90% have been reported. as little is known about the mode of ...200111417041
helicobacter mustelae lipid a structure differs from that of helicobacter pylori.the lipid a structure of the gram-negative bacterium helicobacter mustelae, a ferret gastric pathogen responsible for the onset of gastric diseases in its host, was investigated. two variant lipid a structures were found in the same strain. one structure contained a bisphosphorylated beta-(1-->6)-linked d-glucosamine backbone disaccharide with hydroxytetradecanoic acid in amide linkages. unlike the structure described for the lipid a of the related human helicobacter pylori gastric pathogen, whi ...200111418100
expression of hepatocyte growth factor, transforming growth factor alpha, apoptosis related proteins bax and bcl-2, and gastrin in human gastric cancer.gastric cancer is one of the most frequent neoplasms and a leading cause of the death world-wide. in recent years, epidemiological and animal studies demonstrated a link between gastric cancer and chronic infection with h. pylori. the exact mechanism responsible for the development of gastric cancer in h. pylori-infected patients still remains unclear. there is evidence that the up-regulation of certain growth factors could play an important role in the promotion of the gastric carcinogenesis.200111421874
effects of genotypic differences in cyp2c19 status on cure rates for helicobacter pylori infection by dual therapy with rabeprazole plus amoxicillin.rabeprazole is a potent proton pump inhibitor and is mainly reduced to thioether rabeprazole by a non-enzymatic pathway and partially metabolized to demethylated rabeprazole by cyp2c19 in the liver. we intended to determine a cure rate for helicobacter pylori infection by dual rabeprazole/amoxicillin therapy in relation to cyp2c19 genotype status prospectively. ninety-seven patients with gastritis and h. pylori infection completed the dual therapy with 10 mg of rabeprazole bid and 500 mg of amox ...200111434512
regulation of transcription in helicobacter pylori: simple systems or complex circuits?a common strategy used by both gram-negative and gram-positive bacterial pathogens is based on the synchronisation of virulence gene expression using a variety of regulatory systems and networks to overcome host defence. during the last decade an exponentially growing number of studies on helicobacter pylori, a human pathogen associated with diverse stomach diseases, have mainly focussed on the elucidation of mechanisms and functions of virulence factors. a subset of these studies were focussed ...200111437334
negative selection of t cells by helicobacter pylori as a model for bacterial strain selection by immune evasion.the majority of humans infected with helicobacter pylori maintain a lifelong infection with strains bearing the cag pathogenicity island (pai). h. pylori inhibits t cell responses and evades immunity so the mechanism by which infection impairs responsiveness was investigated. h. pylori caused apoptotic t cell death, whereas campylobacter jejuni did not. the induction of apoptosis by h. pylori was blocked by an anti-fas ab (zb4) or a caspase 8 inhibitor. in addition, a t cell line with the fas re ...200111441100
helicobacter pylori-induced expression of interleukin-8 and cyclooxygenase-2 in ags gastric epithelial cells: mediation by nuclear factor-kappab.helicobacter pylori infection might activate nuclear factor-kappab (nf-kappab), a transcriptional regulator of inducible expression of inflammatory genes, interleukin-8 (il-8) and cyclooxygenase-2 (cox-2). we studied the role of nf-kappab on expression of il-8 and cox-2 in h. pylori-stimulated ags gastric epithelial cells by using antisense oligonucleotide (as odn) for nf-kappab subunit p50 and an antioxidant, glutathione (gsh) as well as a nf-kappab inhibitor, pyrrolidine dithiocarbamate (pdtc) ...200111444469
inhibitory effect of sofalcone on tumor necrosis factor-alpha and interleukin-1 beta production in human monocytes stimulated by helicobacter pylori water extract.we investigated the effect of sofalcone, a synthetic flavonoid derivative of sophoradin, on tumor necrosis factor (tnf)-alpha and interleukin (il)-1 beta production in human monocytes stimulated by helicobacter pylori water extract. h. pylori water extract significantly stimulated tnf-alpha and il-1 beta production by monocytes while incubation with sofalcone (10 micrograms/ml and 50 micrograms/ml) significantly inhibited this increase in tnf-alpha and il-1 beta production. these results suggest ...200111447767
helicobacter pylori: recent advances in the study of its pathogenicity and prevention.helicobacter pylori has acquired great importance during the last two decades, after being recognized as an important pathogen that infects a great portion of the human population. this microorganism is recognized as the main causal agent of chronic gastritis and duodenal ulcers, and it is associated with the subsequent development of gastric carcinoma. the pathogenic mechanisms of h. pylori and their relation to gastric ailments have not been clearly defined. however, at present it is well esta ...200111452701
nf-kappab, inducible nitric oxide synthase and apoptosis by helicobacter pylori infection.oxygen radicals are considered as an important regulator in the pathogenesis of helicobacter pylori (h. pylori)-induced gastric ulceration and carcinogenesis. inflammatory genes including inducible nitric oxide synthase (inos) may be regulated by oxidant-sensitive transcription factor, nuclear factor-kappab (nf-kappab). inos induction has been related to gastric apoptosis. we studied the role of nf-kappab on inos expression and apoptosis in h. pylori-stimulated gastric epithelial ags cells. ags ...200111461773
[helicobacter pylori and gastric carcinoma].among the suspected bacterial causes of cancer, h. pylori is the agent more consistently linked to malignancy. after its discovery in 1983 and the later confirmation as the leading cause of chronic gastritis, several studies were performed to prove an association between h. pylori infection and gastric carcinoma. the epidemiological data have been so strong that in 1994 the international association for research on cancer stated that "there was sufficient evidence" to classify h. pylori as a gro ...200111464496
[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
cyp2c19 genotype related effect of omeprazole on intragastric ph and antimicrobial stability.a combination of proton pump inhibitors and antimicrobials has been applied as an anti-helicobacter pylori (h. pylori) therapy. omeprazole, one of the proton pump inhibitors, is metabolized by cyp2c19. which exhibits genetic polymorphism. it was reported previously that the overall anti-h. pylori efficacy can be related to the cyp2c19 genotype. the main aim of the present study was to obtain a rational explanation for the relationship between the overall anti-h. pylori efficacy and the cyp2c19 g ...200111465416
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
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
implication of gastrin in cyclooxygenase-2 expression in helicobacter pylori infected gastric ulceration.gastroduodenal ulcerations have worldwide distribution and the infection with helicobacter pylori (hp) has been implicated in pathogenesis of this disease. the hp infection is usually accompanied by hypergastrinemia and enhanced generation of prostaglandins (pg), both implicated in the pathogenesis of peptic ulcerations but no study has been undertaken to assess the relationship between the hp infection and coexpression of gastrin and cyclooxygenases (cox), the rate limiting enzymes in the pg pr ...200111519793
helicobacter pylori membrane protein 1: a new carcinogenic factor of helicobacter pylori.considering a suspected link between helicobacter pylori infection and human stomach cancer, a new h. pylori gene for membrane protein 1 (hp-mp1) was recently cloned. because hp-mp1 induces release of inflammatory cytokines and tumor necrosis factor-alpha acts as both initiator and tumor promoter, we studied the possible involvement of hp-mp1 in carcinogenesis of h. pylori. two cell lines, balb/3t3 cells as control and v-ha-ras-transfected balb/3t3 cells (bhas 42 cells) as putative initiated cel ...200111522625
the polymorphic il-1b and il-1rn genes in the aetiopathogenesis of peptic ulcer.besides environmental factors, the genetic background of an individual may contribute to the development and final outcome of peptic ulcer disease. interleukin-1beta (il-1beta) and the interleukin-1 receptor antagonist (il-1ra) are cytokines that play a key role in modulating the inflammatory response in the gastrointestinal mucosa. this study aimed to investigate whether polymorphisms in the il-1b and il-rn genes are involved in the susceptibility to and final outcome of peptic ulcer disease. d ...200111531943
chemotaxis in the human gastric pathogen helicobacter pylori: different roles for chew and the three chev paralogues, and evidence for chev2 phosphorylation.the complete genome sequence of helicobacter pylori has revealed the presence of a novel set of chemotaxis genes including three chev paralogues. chev is a bi-functional protein, the n-terminal domain being homologous to the signalling-complex linker protein chew, while the c-terminal domain is homologous to the response-regulator chey, but its precise function in chemotaxis is unknown. in this study, each of the three chev paralogues were insertionally inactivated in strain 26695 to determine t ...200111535789
epstein-barr virus-associated gastric lymphomas are distinct from mucosa-associated lymphoid tissue-type lymphomas: genetic abnormalities of p53 gene.the authors studied 46 primary gastric lymphomas for expression of the p53 gene by immunohistochemistry and screened for mutations in p53 exon 5-8 by polymerase chain reaction-single strand conformation polymorphism. twenty-five specimens cases were also analyzed for loss of heterozygosity (loh) of chromosomal region 17p12-13.1. in 36 lymphomas negative for epstein-barr virus (ebv) infection, of which 29 were of mucosa-associated lymphoid tissue (malt) type, p53 genetic changes were found in 47. ...200111552717
effect of helicobacter pylori eradication on expression of cyclin d2 and p27 in gastric intestinal metaplasia.cyclins and cyclin-dependent kinase inhibitors play a crucial role in the control of cell cycle transitions. enhanced expression of cyclin d2 and reduced expression of p27kip1 (p27) have been implicated in the pathogenesis of cancer. because intestinal metaplasia has been regarded as a pre-malignant lesion, we investigated the expression of cyclin d2 and p27 in helicobacter pylori-associated chronic gastritis with and without intestinal metaplasia, and followed the changes after h. pylori eradic ...200111552926
a novel immunoassay based on monoclonal antibodies for the detection of helicobacter pylori antigens in human stool.with the premier platinum hpsa eiatrade mark a new enzyme immunoassay was developed for diagnosis of h. pylori infection, using polyclonal antibodies against h. pylori antigens in human stool. here we evaluated femtolab h. pyloritrade mark based on the use of monoclonal antibodies in comparison to established reference methods.200111558058
helicobacter pylori and two ultrastructurally distinct layers of gastric mucous cell mucins in the surface mucous gel layer.helicobacter pylori locate not only on the apical surface of surface mucous cells but also in the mucous gel layer covering the gastric mucosa. the present study was undertaken to observe the mucous gel layer itself and any h pylori in this layer at the electron microscopic level, and to determine whether h pylori proliferate in this layer.200111559642
amoxicillin-loaded polyethylcyanoacrylate nanoparticles: influence of peg coating on the particle size, drug release rate and phagocytic uptake.polyethyleneglycol (peg)-coated polyethylcyanoacrylate (peca) nanoparticles loaded with amoxicillin were prepared and the influence of the peg coating on the particle size, zeta potential, drug release rate and phagocytic uptake by murine macrophages was studied. experimental results show that this colloidal drug delivery system could be useful for intravenous or oral administration. the profile of amoxicillin release from peca nanoparticles system was studied under various conditions similar to ...200111561891
epidemiology of nsaid-related gastroduodenal mucosal injury.non-steroidal anti-inflammatory drugs (nsaids) are among the agents most frequently used against musculoskeletal and rheumatic disorders throughout the world. the gastroduodenal adverse effects include dyspepsia without endoscopically proven damage, asymptomatic endoscopic lesions of submucosal haemorrhage, erosions and ulcers, and-most important-ulcer complications. established risk factors for nsaid-associated ulcer complications include patient-specific factors such as advanced age, female ge ...200111566036
magnetic immuno-pcr assay with inhibitor removal for direct detection of helicobacter pylori in human feces.a pcr protocol was developed to detect helicobacter pylori in human stool specimens. this protocol was based on the association of a magnetic immuno-pcr assay with a technique to remove inhibitors (agarose-embedded dna preparation). of the 47 h. pylori-positive and 57 h. pylori-negative patients included in this study, 38 were positive and 66 were negative by this new protocol. the sensitivity, specificity, and predictive values for a positive or a negative result were 80.9% (95% confidence inte ...200111574617
mrna expression of cytokines and chemokines in the normal gastric surface mucous epithelial cell line gsm06 during bacterial infection with helicobacter felis.a group of the proinflammatory and chemotactic cytokines (chemokines) has been considered as an important factor in the pathomechanism of different bacterial diseases, among them the common helicobacter pylori infection. experimental results obtained with gastric biopsy samples of h. pylori positive patients, and with h. pylori infected tumor originated gastric cell lines indicated that these cytokines have essential roles in the development and maintenance of the immune response and inflammatio ...200111595476
helicobacter pylori infection in children.a number of scientific breakthroughs since h pylori first became recognized as a human pathogen have increased our understanding of the pathogenesis of gastroduodenal disease. in particular, advances in molecular bacteriology and the complete sequencing of the h pylori genome in 1999, and soon thereafter the human genome, provide tools allowing better delineation of the pathogenesis of disease. these molecular tools for both bacteria and host should now be applied to multicenter pediatric studie ...200111595896
[pathogenicity in mice infected with three different strains h. pylori].to observe the differences of colonization and histopathology between caga+ strains and lacking caga by three different strains infecting c57bl/c mice.199911601041
differential expression of laminin isoform (alpha2), integrins (alpha3beta1 and alpha6beta4) and cytokeratin 20 in h. pylori gastritis.the expression of laminin-1 chains (beta1 and gamma1), laminin-2 (merosin), integrin receptors to laminin (alpha3beta1 and alpha6beta4) and cytokeratin (ck20) were studied by immunohistochemical methods in gastric biopsies from antrum of 25 patients. h. pylori gastritis was found in 19 cases and intestinal metaplasia (im) in four from these 19. another 13 biopsies, all with im were immunostained to laminin-2. laminin-1 chains in normal and gastritis areas without im were expressed as a strong, l ...200111642721
analysis of antibody to milk proteins in hiv positive/negative sera using two-dimensional electrophoresis, western blot and immunoassay.homology between the 120 envelope glycoprotein of hiv-1 virus and alpha-lactalbumin (a milk protein) stimulated interest in analysis of antibody in hiv-1 positive plasma to cow's milk. western blots of a two-dimensional (2-d) separation of milk were assayed with nine hiv-1 positive plasmas and nine control sera. the control sera from reference labs represented various disease problems. all nine hiv-1 positive plasma had antibody to between two and five milk proteins. all nine hiv-1 positive plas ...200111678041
[pharmacological study on the pathological changes of the gastric mucosa in helicobacter pylori-infected mongolian gerbils].helicobacter pylori (h. pylori) infection has been recognized to be a causal factor of gastritis, ulcers and gastric cancer in man. using mongolian gerbils (m. gerbils), which are suitable for an h. pylori infection animal model, we examined 1) how h. pylori infection, indomethacin and their combination affects the healing of gastric ulcers and whether or not such factors provoke a relapse of healed acetic acid ulcers; and 2) whether or not eradication of the bacteria with drugs at specified tim ...200111680169
proteome analysis of the common human pathogen helicobacter pylori.the common human pathogen helicobacter pylori is the major cause of gastric and duodenal ulcers. based on the complete genome sequences of two independent isolates more than 1800 protein species have been resolved by two-dimensional gel electrophoresis and more than 200 of them have been identified (http://www.mpiib-berlin.mpg.de/2d-page). using these data, a large range of research areas including strain fingerprinting, protein composition and subcellular localization, gene regulation, and path ...200111681201
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
leptin in the control of gastric secretion and gut hormones in humans infected with helicobacter pylori.leptin, a protein product of obese gene expressed primarily by adipocytes, provides feedback information on the size of energy stores to central ob receptors controlling the food intake, energy expenditure and body weight homeostasis. it has recently been detected in the rat stomach, especially after cholecystokinin (cck) administration and in human stomach infected with helicobacter pylori, but its role in gastric secretory functions in humans has not been revealed. this study was designed to d ...200111686213
molecular basis of colorectal cancer - role of gastrin and cyclooxygenase-2.tumors arising in the colorectal area have worldwide distribution and concern mostly older population being attributed to genetic, dietary and hormonal factors but most recently also to infection with helicobacter pylori (hp). both, hp discovery and molecular biology of colorectal cancer have been recently considered as two of ten greatest advances of gastroenterology at the dawn of 3rd millenium but little information is available regarding the relationship between the hp and colorectal cancer. ...200111687726
cytokeratin immunoreactivity of intestinal metaplasia at normal oesophagogastric junction indicates its aetiology.cytokeratin (ck) 7 and 20 patterns are specific for long and short segments of barrett's oesophagus but their use has not been assessed in intestinal metaplasia arising in macroscopically normal gastro-oesophageal junction (goj).200111709508
comparison of tissue kallikrein and kinin receptor expression in gastric ulcers and neoplasms.recent studies have suggested the possible involvement of the kallikrein-kinin cascade in gastric inflammatory diseases and malignant transformation in peptic ulcers. germ-line mutations of genes responsible for repairing dna mismatch may cause the transformation of chronic peptic ulceration to malignancy. the aim of the study was to compare the expression of the serine protease, tissue kallikrein (tk) and kinin peptide receptors, b1 and b2, in human gastric carcinoma and ulcers. furthermore, ex ...200111710536
current controversies associated with helicobacter pylori infection in the pediatric population.helicobacter pylori is a human bacterial gastric pathogen, fulfilling each of koch's postulates for causal inference for ulceration in children and adults. in addition many reports purport to show that the organism causes a variety of extra-intestinal manifestations in children. this review of the english language literature provides evidence that h. pylori is likely a cause of unexplained iron deficiency (sideropenic) anemia in children, even in the absence of gastrointestinal bleeding. much st ...200111724684
identification of novel immunogenic proteins of helicobacter pylori by proteome technology.cell surface proteins of the human gastric pathogen helicobacter pylori, reference strain ccug 17874, were extracted with acid glycine and fractionated by heparin affinity chromatography. the extracts were subsequently analysed using high-resolution two-dimensional gel electrophoresis (2-de) and immunoblotting. four proteins of low molecular masses (25-30 kda) stained by coomassie r-350, were identified by peptide esi-ms/ms sequencing after in-gel tryptic digestion. the identified proteins were ...200211730836
analysis of laci mutations in big blue transgenic mice subjected to parasite-induced inflammation.parasite infections have long been associated with specific types of human cancers. schistosoma hematobium is an inducer of urinary bladder cancer, helicobacter pylori is a gastric carcinogen, and hepatitis b virus and opisthorchis viverrini are causative agents of hepatocellular carcinoma. another liver fluke, fasciola hepatica, has also been identified as a neoplastic risk agent, primarily in animals. we used f. hepatica-induced inflammation in mice to determine if the presence of an aggressiv ...200111733073
shp-2 tyrosine phosphatase as an intracellular target of helicobacter pylori caga protein.helicobacter pylori caga protein is associated with severe gastritis and gastric carcinoma. caga is injected from the attached helicobacter pylori into host cells and undergoes tyrosine phosphorylation. wild-type but not phosphorylation-resistant caga induced a growth factor-like response in gastric epithelial cells. furthermore, caga formed a physical complex with the src homology 2 domain (sh2)-containing tyrosine phosphatase shp-2 in a phosphorylation-dependent manner and stimulated the phosp ...200211743164
helicobacter pylori-binding gangliosides of human gastric adenocarcinoma.acidic and neutral glycosphingolipids were isolated from a human gastric adenocarcinoma, and binding of helicobacter pylori to the isolated glycosphingolipids was assessed using the chromatogram binding assay. the isolated glycosphingolipids were characterized using fast atom bombardment mass spectrometry and by binding of antibodies and lectins. the predominating neutral glycosphingolipids were found to migrate in the di- to tetraglycosylceramide regions as revealed by anisaldehyde staining and ...200111744628
dip, the database of interacting proteins: a research tool for studying cellular networks of protein interactions.the database of interacting proteins (dip: http://dip.doe-mbi.ucla.edu) is a database that documents experimentally determined protein-protein interactions. it provides the scientific community with an integrated set of tools for browsing and extracting information about protein interaction networks. as of september 2001, the dip catalogs approximately 11 000 unique interactions among 5900 proteins from >80 organisms; the vast majority from yeast, helicobacter pylori and human. tools have been d ...200211752321
human plasma is directly bacteriocidal against helicobacter pylori in vitro, potentially explaining the decreased detection of helicobacter pylori during acute upper gi bleeding.the rapid urease test is the preferred method for detection of h pylori in patients with uncomplicated ulcer disease undergoing egd. however, the sensitivity of this test when performed during upper gi bleeding has been questioned. it has been suggested that false-negative results occur, resulting from buffering effects of blood. the direct effect of blood was evaluated on h pylori growth in ex vivo and in vitro systems.200211756907
helicobacter pylori: strategies for treatment.helicobacter pylori (hp) is a gram-negative bacteria able to live in the human stomach, a very surprising fact considering the acid environment of gastric mucosa. identified by marshall and warren in 1982 [1,2], this bacterium seems aetiologically related to many gastric diseases, previously known as 'acid related diseases'. compelling evidence demonstrates that hp is the most important aetiological agent of gastritis [3], the principal causal factor in peptic ulcer [4], contributes to the genes ...200111772247
effect of cold starvation, acid stress, and nutrients on metabolic activity of helicobacter pylori.helicobacter pylori can transform, in vivo as well as in vitro, from dividing spiral-shaped forms into nonculturable coccoids, with intermediate forms called u forms. the importance of nonculturable coccoid forms of h. pylori in disease transmission and antibiotic treatment failures is unclear. metabolic activities of actively growing as well as nonculturable h. pylori were investigated by comparing the concentrations of cellular atp and total rna, gene expression, presence of cytoplasmic polyph ...200211772603
helicobacter pylori stimulates pepsinogen secretion from isolated human peptic cells.different acid and peptic related gastroduodenal diseases are associated with both increased gastric secretion and helicobacter pylori infection. patients with h pylori associated gastritis or duodenal ulcer have increased serum pepsinogen levels which decrease after eradication. the mechanisms of h pylori induced gastric mucosal damage are not completely understood.200211772960
effects of cyp2c19 gene polymorphism on cure rates for helicobacter pylori infection by triple therapy with proton pump inhibitor (omeprazole or rabeprazole), amoxycillin and clarithromycin in japan.omeprazole is mainly metabolized by cytochrome p450 2c19 (cyp2c19) in the liver. rabeprazole, on the other hand, is mainly metabolized to thioether-rabeprazole via a non-enzymatic pathway and partially metabolized to demethylated-rabeprazole by cyp2c19 in liver cyp2c19 status may affect cure rate for helicobacter pylori infection with proton pump inhibitor triple therapy.200111785712
src is the kinase of the helicobacter pylori caga protein in vitro and in vivo.the gastric pathogen helicobacter pylori uses a type iv secretion system to inject the bacterial caga protein into gastric epithelial cells. within the host cell, caga becomes phosphorylated on tyrosine residues and initiates cytoskeletal rearrangements. we demonstrate here that src-like protein-tyrosine kinases mediate caga phosphorylation in vitro and in vivo. first, the src-specific tyrosine kinase inhibitor pp2 specifically blocks caga phosphorylation and cytoskeletal rearrangements thereby ...200211788577
[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
adams (a disintegrin and metalloproteinase) messenger rna expression in helicobacter pylori-infected, normal, and neoplastic gastric mucosa.helicobacter pylori is a risk factor for gastric cancer, and bacterial-epithelial interactions may be critical in this association. studies using complementary dna arrays indicated that the adam (a disintegrin and metalloproteinase) genes in gastric epithelial cells are differentially expressed after bacterial-epithelial interactions. reverse-transcription polymerase chain reaction analysis of gastric biopsy specimens from patients with and without h. pylori showed that infection was associated ...200211807715
association analysis of polymorphisms at the interleukin-1 locus in essential hypertension.infection with microorganisms such as helicobacter pylori and chlamydia pneumoniae has been associated with coronary heart disease (cad) and hypertension (ht). infection increases the release of pro-inflammatory cytokines, thus facilitating interactions that lead to vascular damage and other effects. we hypothesized that genetically determined differences in activity or responsiveness of cytokine(s) might contribute to ht. the interleukin-1 gene (il1) cluster on chromosome 2q14 contains three re ...200211840488
effects of very long (up to 10 years) proton pump blockade on human gastric mucosa.long-term use of proton pump inhibitors (ppi) has been reported to worsen oxyntic mucosa gastritis and the resulting gland atrophy has been considered a potential risk factor for neoplastic changes in the gastric mucosa.200111842276
identification of helicobacter pylori dna in human cholesterol gallstones.the gallbladder mucosa secretes hydrogen ions and is covered by mucus. the environmental conditions for bacterial colonization are similar to those in the stomach. gallbladder stones often contain dna from enteric bacteria, but no compelling evidence demonstrates that helicobacter spp. have been present. the aim of this study was to establish bacterial dna profiles in cholesterol gallstones with special reference to helicobacter pylori.200211843027
t cell-mediated cytotoxicity via fas/fas ligand signaling in helicobacter pylori-infected gastric corpus.helicobacter pylori infection induces t helper-1 immune responses in inflamed mucosa. however, the role of t cell-mediated cytotoxicity in the induction of epithelial apoptosis is still unclear. the aim of this study was to investigate the involvement of the fas/fas ligand (fas/fas-l) system in the h. pylori-infected gastric corpus.200111843960
review article: natural history and epidemiology of helicobacter pylori infection.helicobacter pylori is a common bacterium infecting about half the world's population. it is causally linked with a diverse spectrum of gastrointestinal clinical disorders including peptic ulcer disease, gastric cancer, and gastric malt lymphoma. the principal reservoir is the human stomach, and transmission probably occurs by person-to-person passage. prevalence rates are generally much higher in developing countries compared to developed countries, although there are subgroups within many regi ...200211849122
helicobacter pylori activates the proto-oncogene c-fos through sre transactivation.epidemiological studies have demonstrated a strong association between helicobacter pylori infection and gastric cancer. however, there have been few detailed studies on the mechanism of cellular proliferation by h. pylori. thus, we examined activation of the proto-oncogene c-fos to elucidate the underlying mechanism of cell proliferation caused by h. pylori. activation of c-fos was evaluated in human gastric cancer cells (tmk1) by northern blot and reporter assays with deletion analysis of the ...200211866445
extracellular ph modulates helicobacter pylori-induced vacuolation and vaca toxin internalization in human gastric epithelial cells.in this study we investigated whether an acidic extracellular ph may inhibit h. pylori-induced internalization of bacterial virulence factors by gastric epithelium, thus preventing ingestion of potentially dangerous luminal contents and resulting cellular damage. the interaction of h. pylori vaca toxin and ammonia (produced by h. pylori urease) with partly polarized gastric mkn 28 cells in culture was investigated at neutral and moderately acidic ph (6.2, compatible with cell viability) by means ...200211890688
effect of lactoferrin on helicobacter felis induced gastritis.lactoferrin possesses antibiotic, antiinflammatory, and immune-modulating properties that may be active against the gastritis-, ulcer- and cancer-inducing bacterium helicobacter pylori. in vitro testing of bovine and human lactoferrin by several laboratories has shown significant bacteriostatic and bactericidal activity. subsequent in vivo testing of bovine lactoferrin in animal models of h. pylori infection has shown beneficial effects of this agent. our laboratory has utilized a mouse model th ...200211908634
bacterial secrets of secretion: euroconference on the biology of type iv secretion processes.type iv secretion systems (tfss) mediate secretion or direct cell-to-cell transfer of virulence factors (proteins or protein-dna complexes) from many gram-negative animal, human and plant pathogens, such as agrobacterium tumefaciens, bartonella tribocorum, bordetella pertussis, brucella suis, helicobacter pylori, legionella pneumophila and rickettsia prowazekii, into eukaryotic cells. bacterial conjugation is also classified as a tfss-like process mediating the spread of broad-host-range plasmid ...200211918819
immunoproteomics of helicobacter pylori infection and relation to gastric disease.the gram negative bacterium helicobacter pylori is a human pathogen which infects the gastric mucosa and causes an inflammatory process leading to gastritis, ulceration and cancer. a systematic, proteome based approach was chosen to detect candidate antigens of h. pylori for diagnosis, therapy and vaccine development and to investigate potential associations between specific immune responses and manifestations of disease. sera from patients with active h. pylori infection (n = 24), a control gro ...200211921447
critical role of an endogenous gastric peroxidase in controlling oxidative damage in h. pylori-mediated and nonmediated gastric ulcer.the objective of the present study is to delineate the mechanism of oxidative damage in human gastric ulcerated mucosa despite the presence of some antioxidant enzymes. we report for the first time the critical role of an endogenous peroxidase, a major h(2)o(2) metabolizing enzyme, in controlling oxidative damage in gastric mucosa. human gastric mucosa contains a highly active peroxidase in addition to the myeloperoxidase contributed by neutrophil. in both non-helicobacter pylori (h. pylori)- an ...200211937299
the role of helicobacter pylori in paediatrics.helicobacter pylori is a bacterium that colonizes the human stomach, especially during childhood. although it has been studied intensively during the past decade, many controversies still exist on many important issues, including the clinical relevance of virulence factors, indications for treatment, recommended procedures for diagnosis and the typical symptom profile, among others. the lack of double-blind, placebo-controlled studies in children illustrates the paucity of hard scientific data, ...200111964850
removal of mucus for ultrastructural observation of the surface of human gastric epithelium using pronase.helicobacter pylori adhering to the human gastric epithelium causes gastric diseases such as ulcer, carcinoma and lymphoma. it is thus important to observe in detail both the surface of the epithelial cells and the h. pylori that adhered to it for the elucidation of h. pylori-induced diseases by scanning electron microscopy (sem). since the thick mucus layer blocks the observation of the cell surface and the bacteria, it is generally eliminated during the processing for sem by roughly mechanical ...200211966871
differential glycosylation of mhc class ii molecules on gastric epithelial cells: implications in local immune responses.class ii major histocompatibility complex (mhc) expression is a hallmark of antigen presenting cells (apc). human gastric epithelial cells (gec) express class ii mhc and this expression increases during infection with helicobacter pylori as does the number of cd4 t cells found adjacent or in between epithelial cells. these observations suggested that human gec act as apcs. to characterize and compare class ii mhc complexes with those present in conventional apc, immunoprecipitated class ii mhc f ...200211975982
[gastric epithelial cell apoptosis and il-18]. 200211979769
reversibility of heterotopic proliferative glands in glandular stomach of helicobacter pylori-infected mongolian gerbils on eradication.helicobacter pylori (hp) infection is an important factor in human gastric disorders. mongolian gerbils can be easily infected with hp and represent excellent experimental models to clarify the role of hp in chronic active gastritis, peptic ulcers, intestinal metaplasia, and gastric carcinoma. we have proved the enhancing effects of hp infection on all histological types of gastric cancers in mongolian gerbils exposed to chemical carcinogens. heterotopic proliferative glands (hpgs) also frequent ...200211985786
diagnosis of a gastric mucosa-associated lymphoid tissue lymphoma by endoscopic ultrasonography-guided biopsies in a patient with a parotid gland localization.we report the case of a 32-year-old man with a low-grade mucosa-associated lymphoid tissue (malt) lymphoma of the parotid gland associated with sjögren syndrome. he underwent an upper endoscopy as part of the screening of a gastric localization which showed a diffuse non-specific gastritis. however, endoscopic ultrasonography (eus) evidenced a focal wall thickening of the vertical portion of the smaller curvature. eus-guided biopsies of this area disclosed a malt lymphoma, whereas biopsies under ...200211989843
inhibition of cell proliferation and induction of apoptosis by helicobacter pylori through increased phosphorylated p53, p21 and bax expression in endothelial cells.microcirculation plays a crucial role in mucosal physiological function as well as repair of gastric mucosal damage. endothelial cell damage is known to disturb microcirculation and suppress angiogenesis. therefore, the direct effect of helicobacter pylori on endothelial cells in vitro was investigated with h. pylori water extract. the effect of h. pylori water extract on cell proliferation and apoptosis of human umbilical vein endothelial cells (huvecs) was evaluated. the ratio of brdu-positive ...200211990490
[appearance of helicobacter pylori antigen in stool specimens of children with chronic gastritis].various examinations are successfully applied for the diagnosis of helicobacter pylori infection, but non-invasive techniques are still required for the therapeutic monitoring after eradication therapy, especially in children. in the search for new non-invasive techniques to diagnose h. pylori infection, we evaluated an eia for h. pylori antigen in stool (hpsa). our study included 62 h. pylori-positive children with chronic gastritis. h. pylori infection was diagnosed by using the culture of gas ...200211995244
helicobacter pylori infection in skin diseases: a critical appraisal.more than 50% of the human population have long-term helicobacter pylori infection, causing, in some cases, severe diseases such as peptic ulcers and stomach cancer. in the last few years several extra-gastrointestinal disorders have been associated with h. pylori infection. this review summarized the current medical literature, identified through hand searching and medline research, including our own studies, with regard to h. pylori and skin diseases. from the literature it can be seen that th ...200212010072
effects of n-alpha-methyl-histamine on human h(2) receptors expressed in cho cells.production of n-alpha-methyl-histamine (namh), a histamine h(3) receptor (h3r) agonist, is reportedly promoted in helicobacter pylori infected human gastric mucosa. namh was suggested to act directly on histamine h(2) receptors (h2rs) in animals to stimulate acid secretion and to be a h2r agonist. as h2rs and h3rs play different roles in gastric acid secretion, it is very important to verify that namh is a h2r agonist.200212010879
interrelation between abh blood group 0, lewis(b) blood group antigen, helicobacter pylori infection, and occurrence of peptic ulcer.helicobacter pylori is a human pathogen that causes chronic gastritis and peptic ulcers. epidemiological studies demonstrated that individuals who are blood group 0 positive or represent non-secretors of their blood group antigens are more likely to develop peptic ulcers. the lewis(b) blood group antigen has been reported to mediate the attachment of h. pylori to human gastric mucosa. the aim of this study was to examine the interrelation between le(a-b+) phenotype, blood group 0, h. pylori infe ...200212016560
identification of surface proteins of helicobacter pylori by selective biotinylation, affinity purification, and two-dimensional gel electrophoresis.helicobacter pylori is a widespread human pathogen that can cause gastric ulcers and cancer. to identify surface proteins that may play a role in pathogen-host interactions and represent potential targets for the control of this infection, we selectively biotinylated intact h. pylori with the hydrophilic reagent sulfosuccinimidyl-6-(biotinamido)-hexanoate and purified the labeled proteins by membrane isolation, solubilization, and affinity chromatography. after separation of 82 biotinylated prot ...200212023975
adherence of helicobacter pylori to gastric epithelial cells and mucosal inflammation.adherence of helicobacter pylori to the gastric epithelium is believed to be an important step in the induction of active inflammation of the mucosal layer. however, structural evidence showing a quantitative relationship between the adherence of h. pylori and severity of gastric mucosal inflammation is lacking. we therefore investigated the correlations between severity of gastritis and adherence of morphologically different forms of h. pylori. fifty-seven biopsy specimens from the gastric bodi ...200212024112
proteome analysis of highly immunoreactive proteins of helicobacter pylori.identification of the immunoreactive proteins of helicobacter pylori is important for the development of both diagnostic tests and vaccines relating to the organism. our aim was to determine whether there are significant differences between human igg and iga reactivities to individual h. pylori proteins, and whether patterns of immunoreactivity are sustained across different strains of h. pylori.200212047323
a candidate oral vaccine to helicobacter pylori fusion protein of hspa and ctxb.heat-shock protein a subunit(hspa), an effective immunogen may stimulate the immunoresponse in human body against challenge of h.pylori. the b subunit of cholera toxin (ctxb) has been proved to be a potent mucosal immunogen, actas an adjuvant for vaccine targeted for delivery to the mucosal-associated lymphoid tissue. a recombinant plasmid expressing bivalent antigen of hspa and ctxb subunit was constructed as follows. hspa and ctxb gene was amplified by pcr. the dna products of hspa and ctxb we ...200112050801
helicobacter pylori infection in rural china: demographic, lifestyle and environmental factors.although helicobacter pylori is one of the most common human bacterial infections worldwide, its mode of transmission is unclear.200212055167
microaerophilic conditions permit to mimic in vitro events occurring during in vivo helicobacter pylori infection and to identify rho/ras-associated proteins in cellular signaling.molecular dissection of the mechanisms underlying helicobacter pylori infection suffers from the lack of in vitro systems mimicking in vivo observations. a system was developed whereby human epithelial cells (caco-2) grown as polarized monolayers and bacteria can communicate with each other under culture conditions optimal for each partner. caco-2 cells grown on filter supports were inserted in a vertical position into diffusion chambers equilibrated with air and 5% co(2) at their basolateral su ...200212058029
expression of g1 phase cyclins in human gastric cancer and gastric mucosa of first-degree relatives.the aim of this study was to investigate the expression of d-type cyclins and cyclin e in gastric cancer patients (n = 34), in healthy first-degree relatives of gastric cancer patients (n = 29), and in control subjects (n = 18). expression of cyclins d1, d2, d3, and e was determined by rt-pcr. localization of cyclin expression was determined by immunohistochemistry. expression of cyclins d2, d3, and e was more frequently detected in tumor tissue compared with tumor-free gastric mucosa (p < 0.05) ...200212064799
helicobacter pylori-induced oxidative stress and dna damage in a primary culture of human gastric mucosal cells.helicobacter pylori has been identified in the pathogenesis of chronic active gastritis and peptic ulcer disease and is epidemiologically linked to gastric cancer and lymphoma. our previous studies have demonstrated enhanced production of reactive oxygen species (ros) in cultured gastric adenocarcinoma cells (atcc crl/1739) in association with h. pylori. recently, we have isolated and cultured normal human gastric mucosal cells (gmc) from h. pylori-negative endoscopic biopsies. the integrity of ...200212064819
helicobacter pylori infection and infertility.to determine (1) the prevalence of helicobacter pylori infection in male and female patients with reproductive disorders and controls; (2) the presence of anti-h. pylori antibodies in samples of follicular fluid, vaginal secretions and sperm; and (3) the existence of a structural homology between a major spermatozoa protein, tubulin, and h. pylori proteins.200212072601
expression of mucins (muc1, muc2, muc5ac, and muc6) and type 1 lewis antigens in cases with and without helicobacter pylori colonization in metaplastic glands of the human stomach.helicobacter pylori (h. pylori) causes gastritis and intestinal metaplasia (tm) that may evolve to gastric carcinoma. paradoxically, im leads to clearing of h. pylori, except for some cases in which it persists in damaging the mucosa. the objective of this study was to compare the profile of mucins and type 1 lewis antigens in im cases with and without h. pylori. gastric biopsies (n=32) were double-stained using immunohistochemistry (muc1, muc2, muc5ac, muc6, le(a), sialyl-le(a), and le(b)) and ...200212081201
an antibody to vaca of helicobacter pylori in cerebrospinal fluid from patients with guillain-barre syndrome.to detect antibodies to recombinant vacuolating cytotoxin (r-vaca) of helicobacter pylori in cerebrospinal fluid (csf) from patients with guillain-barre syndrome (gbs).200212082053
expression of cell-cycle related proteins in helicobacter pylori gastritis and association with gastric carcinoma.helicobacter pylori (h. pylori) infection is associated with changes in epithelial turnover, through their significance of these in gastric carcinogenesis is still controversial. the purpose of this study was to determine the influence of h. pylori infection on cell proliferation and the relation with the cell-cycle regulators, and finally to provide insights into the mechanism by which h. pylori may lead to gastric carcinogenesis. we investigated ki-67, p53, p21(waf1/cip1), cyclin d1 expression ...200212088113
[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
correlation between helicobacter pylori infection and il-18 mrna expression in human gastric biopsy specimens.our data indicate that h. pylori infection is associated with active interleukin-18 production in patients with chronic gastritis. different cell types appear to be involved in this activity and may play a role in the development of immunopathologic damage.200212095959
interleukin 1beta polymorphisms increase risk of hypochlorhydria and atrophic gastritis and reduce risk of duodenal ulcer recurrence in japan.interleukin-1 beta (il-1beta) polymorphisms are associated with increased risk of gastric cancer in whites. this study aimed to examine effects of these polymorphisms on gastric acid secretion, atrophic gastritis, and risk of peptic ulcer in japan.200212105837
analysis of p53 mutations and helicobacter pylori infection in human and animal models.p53 gene mutations are believed to play a critical role in the development of gastric carcinoma. we examined the relation between helicobacter pylori infection and p53 gene mutations of the gastric mucosa in human and animal models.200212109656
helicobacter pylori-induced activation of human endothelial cells.helicobacter pylori infection causes active chronic inflammation with a continuous recruitment of neutrophils to the inflamed gastric mucosa. to evaluate the role of endothelial cells in this process, we have examined adhesion molecule expression and chemokine and cytokine production from human umbilical vein endothelial cells stimulated with well-characterized h. pylori strains as well as purified proteins. our results indicate that endothelial cells actively contribute to neutrophil recruitmen ...200212117971
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