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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
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
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
[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
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
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
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
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
effects of rabeprazole, lansoprazole and omeprazole on intragastric ph in cyp2c19 extensive metabolizers.to investigate the inhibitory effects on gastric acid secretion of three proton pump inhibitors, omeprazole, lansoprazole and rabeprazole, using a three-way crossover design in healthy helicobacter pylori-negative,s-mephenytoin 4'-hydroxylase (cyp2c19) homo- and hetero-extensive metabolizers.200212269976
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
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
effect of mannitol on helicobacter pylori-induced cyclooxygenase-2 expression in gastric epithelial ags cells.oxygen radicals have been considered to be important regulatory molecules in helicobacter pylori-induced gastric ulceration and carcinogenesis. h. pylori-induced inflammation has been shown to be associated with cyclooxygenase-2 (cox-2) expression in experimental animals and human patients. this study aimed to determine if h. pylori produces oxygen radicals and induces cox-2 expression in gastric epithelial cells. a further aim was to resolve whether or not the h. pylori-induced cox-2 expression ...200212393940
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
randomized open trial for comparison of proton pump inhibitors in triple therapy for helicobacter pylori infection in relation to cyp2c19 genotype.genetic polymorphism of cytochrome p450 (cyp) 2c19 influences the efficacy of helicobacter pylori eradication therapy with a proton pump inhibitor (ppi) and amoxicillin. however, in triple therapy (ppi plus amoxicillin and clarithromycin), little is known about the impact of cyp2c19 polymorphism, or the use of rabeprazole, which is not well metabolized by cyp2c19. the efficacy of three ppi (omeprazole, lansoprazole, and rabeprazole) in a 1-week triple regimen were compared in relation to cyp2c19 ...200212121503
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
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
[association between helicobacter pylori caga strain infection and expression of cyclooxygenase 2 in gastric carcinoma].to observe the expression of cyclooxygenase 2 (cox-2) in tissues of human gastric cancer and explore the association between helicobacter pylori caga strain infection and the expression of cox-2 so as to provide a theoretical basis for early prevention of gastric cancer.200212126507
helicobacter pylori caga protein activates serum response element-driven transcription independently of tyrosine phosphorylation.infection with helicobacter pylori possessing the cag pathogenicity island (pai) is associated with severe gastritis and gastric cancer. caga protein, one of the products of cag pai, is translocated into epithelial cells, where cytoskeletal rearrangements occur as a result of caga tyrosine (tyr) phosphorylation. here we identify a new role for caga protein as an activator of host cell signaling.200212454853
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
cancer prevention and therapy with kiwifruit in chinese folklore medicine: a study of kiwifruit extracts.kiwi gold fruits were extracted successively with hexane, acetone, methanol and 70% methanol, and further fractionated by silica gel and ods column chromatographies for the assays of various biological activities. five fractions h1, h2 (hexane extract), al, a2 (acetone extract) and m2 (methanol extract) showed selective cytotoxic activity against human oral tumor cell lines, which was more sensitive than human gingival fibroblasts. more hydrophilic fractions [70m3, 70m4, 70m5] of 70% methanol ex ...200212127237
genome-scale metabolic model of helicobacter pylori 26695.a genome-scale metabolic model of helicobacter pylori 26695 was constructed from genome sequence annotation, biochemical, and physiological data. this represents an in silico model largely derived from genomic information for an organism for which there is substantially less biochemical information available relative to previously modeled organisms such as escherichia coli. the reconstructed metabolic network contains 388 enzymatic and transport reactions and accounts for 291 open reading frames ...200212142428
new strategies for the prevention and treatment of helicobacter pylori infection.helicobacter pylori infects the stomach of > 50% of the human population worldwide, with higher prevalence in the developing countries. a strict correlation between h. pylori infection and gastroduodenal diseases has been demonstrated, including gastritis, peptic ulcer and gastric cancer. current therapies against h. pylori consist of an antisecretory plus antibiotics. these therapies are effective in 80 - 90% of the cases; presently, no alternative therapies have been shown to give comparable o ...200212150706
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
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
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
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
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
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
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
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
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
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
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
[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
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
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
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
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
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
[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
vaccination against helicobacter pylori in non-human primate models and humans.several vaccination studies have been performed in monkeys and humans testing the feasibility of prophylactic and therapeutic immunizations against helicobacter pylori. the monkey studies showed that immune responses were induced by oral vaccination with the mucosal adjuvant lt (escherichia coli heat-labile enterotoxin), parenteral administration with a cationic lipid adjuvant, and by mucosal priming followed by parenteral boosts. both prophylactic and therapeutic activities were demonstrated in ...200111309150
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
biological activity of kiwifruit peel extracts.various bioactive substances in kiwifruit extracts were fractionated by organic solvent extractions, followed by silica gel and ods chromatographies. both cytotoxic activity and multi-drug resistance reversal activity were found in the less polar fractions. cytotoxic activity was not always parallel the radical intensity. antibacterial activity was distributed into various fractions and all fractions were inactive against candida albicans and h. pylori. only 70% methanol extracts showed anti-hum ...200111406859
heat shock protein 70 (hsp70) in gastric adaptation to aspirin in helicobacter pylori infection.we have recently shown that adaptation of gastric mucosa to aspirin (asa) is disturbed in helicobacter pylori (h. pylori)-infected human stomach, but can be restored by eradication of the bacterium. the aim of this study was 1) to evaluate the influence of h. pylori on expression of heat shock protein 70 (hsp70) during asa ingestion in these subjects and in mice model and 2) to evaluate, whether altered hsp70 expression might be associated with different adaptation to asa in h. pylori-positive a ...200111321509
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
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
human herpesvirus 7 is latent in gastric mucosa.chronic gastritis is associated frequently with persistent infection by helicobacter pylori. however, not all patients with chronic gastritis have evidence of h. pylori infection, suggesting that other factors might contribute to the development of gastritis. the present study was undertaken to evaluate a possible etiologic role of human herpesvirus 7 (hhv-7). hhv-7 dna was detected in about 80% of gastric biopsies, both in healthy mucosa from individuals without evidence of inflammation and in ...200111241458
[cancer and prevention].the aim of the study was to estimate the preventable potential of various types of cancer in denmark on the basis of present knowledge.200111218778
pcr-based diagnosis of helicobacter pylori infection and real-time determination of clarithromycin resistance directly from human gastric biopsy samples.a novel pcr detection assay that amplifies the helicobacter pylori-specific vacuolating cytotoxin gene (vaca) and thus enables rapid diagnosis of infection is described. additionally, a real-time probe hybridization melting point analysis assay to detect all three mutations in the 23s rrna gene associated with clarithromycin resistance was applied directly to antral gastric biopsy samples. comparison with culture and an alternative pcr assay targeting the 16s rrn gene showed that the vaca assay ...200111283030
emergence of diverse helicobacter species in the pathogenesis of gastric and enterohepatic diseases.since helicobacter pylori was first cultivated from human gastric biopsy specimens in 1982, it has become apparent that many related species can often be found colonizing the mucosal surfaces of humans and other animals. these other helicobacter species can be broadly grouped according to whether they colonize the gastric or enterohepatic niche. gastric helicobacter species are widely distributed in mammalian hosts and are often nearly universally prevalent. in many cases they cause an inflammat ...200111148003
dynamin is involved in human epithelial cell vacuolation caused by the helicobacter pylori-produced cytotoxin vaca.the helicobacter pylori-produced cytotoxin vaca induces intracellular vacuolation. to elucidate the molecular mechanism of vacuole formation by vaca, we examined the participation of dynamin, a gtpase functioning in intracellular vesicle formation, in human hela cells. immunocytochemistry revealed that endogenous dynamin was localized to vacuoles induced by vaca. in cells transiently transfected with a gtpase-defective (dominant-negative) dynamin mutant, vaca failed to induce vacuolation. in con ...200111160160
a new strategy for evaluation of the eradication treatment of helicobacter pylori: validation of the analysis of mucin composition in human gastric juice.the change in the mucin composition of human gastric juice has been investigated in patients before and after the eradication of the helicobacter pylori (h. pylori) infection. we confirmed the successful eradication of h. pylori in all 17 patients. the gastric luminal mucins were divided into three fractions by ion-exchange chromatography using a discontinuous salt gradient with three salt steps. although there was a significant variation in the proportion of the mucin content in each fraction a ...200111163025
[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
acute measles gastric infection.we describe the case of a 44-year-old man who was referred for gastroscopy because of abdominal pain. during endoscopy, inflammatory changes of the antrum and corpus mucosa were clearly visible, and biopsy samples from the antrum and corpus mucosa were taken. at histology, routine hematoxylin and eosin staining showed characteristics indicative of so-called ex-helicobacter pylori-gastritis that had developed after antibiotic treatment 2 years ago. additional large, bizarre inclusion bodies and c ...200111176076
helicobacter pylori-mediated transcriptional regulation of the human beta-defensin 2 gene requires nf-kappab.human beta-defensin 2 (hbd-2) is an antimicrobial peptide involved in host defence against bacterial infection in epithelial tissues. its levels are dramatically increased after bacterial infection. the involvement of nf-kappab in helicobacter pylori-mediated induction of hbd-2 promoter activity was examined. a luciferase reporter plasmid containing the hbd-2 promoter extending from -2110 base pairs to -1 was transiently expressed in mkn45 cells, and promoter activity was determined after incuba ...200111207625
[the role of helicobacter pylori infection and effect of eradication in experimental animal models of gastric carcinogenesis].helicobacter pylori (hp) was concluded to be 'a definite carcinogen' by who/iarc in 1994. we have demonstrated that hp infection enhances chemical carcinogen-induced stomach carcinogenesis in mongolian gerbils (mgs) using n-methyl-n'-nitro-n-nitrosoguanidine or n-methyl-n-nitrosourea. not only well-differentiated but also poorly differentiated and signet ring cell types of cancers are observed, mimicking the human case. eradication of hp was found to be effective of preventing enhancing effects. ...200111218411
association between caga+ helicobacter pylori infection and p53, bax and transforming growth factor-beta-rii gene mutations in gastric cancer patients.we assessed the possible association between caga+ helicobacter pylori infection and gastric carcinogenesis in gastric cancer patients. gastric biopsy specimens were obtained from 64 patients with gastric cancer and were histologically classified into intestinal and diffuse types. h. pylori infection was determined by cultivation, flaa-pcr and serum antibody against caga. p53, bax and transforming growth factor-beta-rii (tgfbeta-rii) gene mutations were analyzed by pcr-sscp and direct sequencing ...200111251969
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
mucosal protective effects of ecabet sodium: pepsin inhibition and interaction with mucus.pepsin, acid and helicobacter pylori are major factors in the pathophysiology of peptic ulcer disease and reflux oesophagitis. ecabet sodium reduces the survival of h. pylori in the stomach and inhibits pepsin activity in the gastric juice of experimental animals. here we have investigated the effects of ecabet sodium on some of the factors involved in the dynamics of the mucosal barrier, i.e. pepsins and mucins. this study used gastric juice obtained from 12 non-symptomatic volunteers and nine ...200111256980
comparative analysis of colonization of helicobacter pylori and glycolipids receptor density in mongolian gerbils and mice.the mongolian gerbil has been used as an excellent experimental animal model for studying helicobacter pylori infection because it can stably colonize and induce severe chronic gastritis, ulceration, and cancer-simulating human diseases in this animal. in contrast, h. pylori can only induce mild inflammation in many mouse models. the aim in this study is to clarify the difference of induction of pathological lesions in the two animal models. spf icr mice and mongolian gerbils were inoculated wit ...200111270796
helicobacter pylori infection in an urban african population.we have studied 221 adults drawn from an impoverished urban population with high human immunodeficiency virus (hiv) seroprevalence (35%) to determine the prevalence of gastroduodenal pathology and its relationship to serological markers of helicobacter pylori virulence proteins and other potential environmental and immunological determinants of disease including hiv infection. eighty-one percent were h. pylori seropositive, and 35% were hiv seropositive. urban upbringing and low cd4 count were a ...200111283050
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 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
gastric cancer and human leukocyte antigen: distinct dq and dr alleles are associated with development of gastric cancer and infection by helicobacter pylori.dna and sera from 130 cases of gastric cancer and 263 population-based controls were analyzed to study the association of hla class ii dr-dq alleles with helicobacter pylori (hp) infection and the risk for gastric cancer. presence of the dqa1*0102 allele was inversely and significantly associated with hp seropositivity (p = 2 x 10(-5)), which is an independent replication of previous findings. however, this inverse relationship with hp did not correspond with a reduced risk of gastric cancer. at ...200111289148
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
type iv secretion: intercellular transfer of macromolecules by systems ancestrally related to conjugation machines.bacterial conjugation systems are highly promiscuous macromolecular transfer systems that impact human health significantly. in clinical settings, conjugation is exceptionally problematic, leading to the rapid dissemination of antibiotic resistance genes and other virulence traits among bacterial populations. recent work has shown that several pathogens of plants and mammals - agrobacterium tumefaciens, bordetella pertussis, helicobacter pylori and legionella pneumophila - have evolved secretion ...200111309113
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
interaction of helicobacter pylori with professional phagocytes: role of the cag pathogenicity island and translocation, phosphorylation and processing of caga.chronic infection of the human gastric mucosa with helicobacter pylori is a major cause of gastroduodenal pathologies, including peptic ulcerations, mucosa-associated lymphoid tissue (malt) lymphoma and adenocarcinoma. helicobacter pylori strains carrying the cag pathogenicity island, which encodes an active type iv protein secretion system (cag+ or type i strains), are preferentially associated with strong gastric inflammation and severe disease. we show here that cag+ h. pylori strains use the ...200111207617
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 pylori neutrophil-activating protein stimulates tissue factor and plasminogen activator inhibitor-2 production by human blood mononuclear cells.helicobacter pylori neutrophil-activating protein (hp-nap) is a virulence factor that activates phagocytic nadph-oxidase. the effect of hp-nap on the production of tissue factor (tf), plasminogen activator inhibitor-2 (pai-2), and urokinase-type plasminogen activator (u-pa) by human blood mononuclear cells (mnc) was evaluated by using functional and immunological assays and mrna analysis. hp-nap induced time- and dose-dependent increases in tf and pai-2, with a maximal effect at 300 nmol/l (>15- ...200111237830
the design of vaccines against helicobacter pylori and their development.helicobacter pylori is a gram negative, spiral, microaerophylic bacterium that infects the stomach of more than 50% of the human population worldwide. it is mostly acquired during childhood and, if not treated, persists chronically, causing chronic gastritis, peptic ulcer disease, and in some individuals, gastric adenocarcinoma and gastric b cell lymphoma. the current therapy, based on the use of a proton-pump inhibitor and antibiotics, is efficacious but faces problems such as patient complianc ...200111244046
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
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
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
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
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