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helicobacter pylori--a seasoned pathogen by any other name.helicobacter pylori is a well known inhabitant of human stomach which is linked to peptic ulcer disease and gastric adenocarcinoma. it was recently shown in several studies that h. pylori can be harnessed as a surrogate marker of human migration and that its population structure and stratification patterns exactly juxtapose to those of homo sapiens. this is enough a testimony to convey that h. pylori may have coevolved with their host. several protective effects of h. pylori colonization have be ...200920030808
diagnostic esophago-gastro-duodenoscopy (egd) in patients with aids-related upper gastrointestinal abnormalities.gastrointestinal (gi) diseases are common among patients infected with human immunodeficiency virus (hiv), and may involve the entire gi tract. the aim of the article is to investigate the prevalence of various upper gastrointestinal abnormalities in patients with aids.200920214216
identification of small noncoding rnas in helicobacter pylori by a bioinformatics-based approach.small noncoding rnas (srnas) are a group of regulatory rna molecules normally without a protein-coding function. in recent years, the importance of srnas as mediators of gene expression in bacteria has begun to be recognized. more than 70 srnas have been known in escherichia coli. however, little is known about srnas in helicobacter pylori, a human pathogen associated with gastric diseases. here, we systematically identified srnas in the h. pylori genome by a computational approach based on gene ...200919123032
genome sequence analysis of helicobacter pylori strains associated with gastric ulceration and gastric cancer.persistent colonization of the human stomach by helicobacter pylori is associated with asymptomatic gastric inflammation (gastritis) and an increased risk of duodenal ulceration, gastric ulceration, and non-cardia gastric cancer. in previous studies, the genome sequences of h. pylori strains from patients with gastritis or duodenal ulcer disease have been analyzed. in this study, we analyzed the genome sequences of an h. pylori strain (98-10) isolated from a patient with gastric cancer and an h. ...200919123947
expression of helicobacter pylori caga domains by library-based construct screening.highly pathogenic strains of helicobacter pylori use a type iv secretion system to inject the caga protein into human gastric cells. there, caga associates with the inner side of the membrane and is tyrosine-phosphorylated at epiya motifs by host kinases. the phosphorylation triggers a series of interactions between caga and human proteins that result in a dramatic change of cellular morphology. structural and functional analyses of the protein have proved difficult, due to the proteolytically s ...200919143840
helicobacter pylori caga phosphorylation-independent function in epithelial proliferation and inflammation.caga, a major virulence factor of helicobacter pylori (hp), is delivered into gastric epithelial cells and exists in phosphorylated and nonphosphorylated forms. the biological activity of the phosphorylated form is well established; however, function(s) of the nonphosphorylated form remain elusive. here, we report that a conserved motif in the c-terminal region of caga, which is distinct from the epiya motifs used for phosphorylation and which we designate crpia (conserved repeat responsible for ...200919154985
the peopling of the pacific from a bacterial perspective.two prehistoric migrations peopled the pacific. one reached new guinea and australia, and a second, more recent, migration extended through melanesia and from there to the polynesian islands. these migrations were accompanied by two distinct populations of the specific human pathogen helicobacter pylori, called hpsahul and hspmaori, respectively. hpsahul split from asian populations of h. pylori 31,000 to 37,000 years ago, in concordance with archaeological history. the hpsahul populations in ne ...200919164753
effect of helicobacter pylori's vacuolating cytotoxin on the autophagy pathway in gastric epithelial cells.host cell responses to helicobacter pylori infection are complex and incompletely understood. here, we report that autophagy is induced within human-derived gastric epithelial cells (ags) in response to h. pylori infection. these autophagosomes were distinct and different from the large vacuoles induced during h. pylori infection. autophagosomes were detected by transmission electron microscopy, conversion of lc3-i to lc3-ii, gfp-lc3 recruitment to autophagosomes, and depended on atg5 and atg12. ...200919164948
helicobacter pylori mutants defective in the clpp atp-dependant protease and the chaperone clpa display reduced macrophage and murine survival.the atp-dependent caseinolytic proteases (clp) are important in resistance against environmental stresses, antibiotic treatments and host immune defences for a number of pathogenic bacteria. clpp is the proteolytic subunit, whilst clpa acts both as a chaperone and as an atpase driving the degradation of damaged or mis-made proteins. the gastric pathogen helicobacter pylori infects approximately half of the world's population and can cause gastric or duodenal ulcers, gastric malignancies and muco ...200918992803
helicobacter pylori vaca-induced inhibition of gsk3 through the pi3k/akt signaling pathway.helicobacter pylori vaca toxin contributes to the pathogenesis and severity of gastric injury. we found that incubation of az-521 cells with vaca resulted in phosphorylation of protein kinase b (akt) and glycogen synthase kinase-3beta (gsk3beta) through a pi3k-dependent pathway. following phosphorylation and inhibition of gsk3beta,beta-catenin was released from a gsk3beta/beta-catenin complex, with subsequent nuclear translocation. methyl-beta-cyclodextrin (mcd) and phosphatidylinositol-specific ...200918996844
zn2+-linked dimerization of ureg from helicobacter pylori, a chaperone involved in nickel trafficking and urease activation.the biosynthesis of the active metal-bound form of the nickel-dependent enzyme urease involves the formation of a lysine-carbamate functional group concomitantly with the delivery of two ni(2+) ions into the precast active site of the apoenzyme and with gtp hydrolysis. in the urease system, this role is performed by ureg, an accessory protein belonging to the group of homologous p-loop gtpases, often required to complete the biosynthesis of nickel-enzymes. this study is focused on ureg from heli ...200918767150
role of cyclooxygenase-2 functional gene polymorphisms in helicobacter pylori induced gastritis and gastric atrophy.in india, the role of host genetic factors is poorly studied for helicobacter pylori associated diseases. therefore, we evaluated the association of functionally relevant cox-2 gene polymorphisms (-765 g>c and +8473 t>c) in gastritis and precancerous lesions susceptibility. after upper gi endoscopy, 130 rapid urease test positive patients with non-ulcer dyspepsia, also showed positivity for h. pylori using modified geimsa staining and anti-caga igg serology were included. all patients and 260 as ...200918825488
expression of beta-defensin 4 is increased in human gastritis.infection with helicobacter pylori (h. pylori) leads to the initiation of innate immune responses with increased antimicrobial peptide (amp) expression in the gastric epithelium. this study aimed to determine the expression of the novel peptides beta-defensin 4 (hbd-4) and rnase 7 in infectious and non-infectious gastritis. furthermore, pattern recognition receptors and mechanisms of regulation were characterized.200919200166
cancer prevention by vaccination against hepatitis b.chronic inflammation caused by persistent infection is closely related to a number of cancers; these include hepatitis b (hbv) or c and hepatoma, human papilloma virus and cervical cancer, and helicobacter pylori and gastric cancer. the first evidence of cancer prevention by vaccination in humans was provided by hbv vaccination in infants. chronic hbv is related to approximately 60%-90% of hepatocellular carcinomas (hcc) in adults and nearly 100% of childhood hcc in areas endemic for hbv infecti ...200919213561
helicobacter pylori, asthma and allergy.bronchial asthma and allergic diseases are orchestrated by t-cells producing t-helper type 2 (th2) cytokines, such as interleukin-4 (il-4) and il-5, and are inhibited by th1 responses. helicobacter pylori has chronically infected the human population for c. 100,000 years and preferentially elicits a th1 mucosal immune response with the production of interferon-gamma and il-12. among several bacterial factors, the neutrophil-activating protein of h. pylori (hp-nap) not only plays a key role in dr ...200919220467
differences in genome content among helicobacter pylori isolates from patients with gastritis, duodenal ulcer, or gastric cancer reveal novel disease-associated genes.helicobacter pylori establishes a chronic infection in the human stomach, causing gastritis, peptic ulcer, or gastric cancer, and more severe diseases are associated with virulence genes such as the cag pathogenicity island (pai). the aim of this work was to study gene content differences among h. pylori strains isolated from patients with different gastroduodenal diseases in a mexican-mestizo patient population. h. pylori isolates from 10 patients with nonatrophic gastritis, 10 patients with du ...200919237517
therapeutic strategies for hepatitis- and other infection-related immune thrombocytopenias.secondary thrombocytopenia may result from autoimmune diseases, lymphoproliferative disorders, infections, myelodysplastic syndromes, common variable immunodeficiency, agammaglobulinemia, hypogammaglobulinemia, immunoglobulin a deficiency, and drugs. the presence of thrombocytopenia may result from chronic infections with hepatitis c virus (hcv), human immunodeficiency virus (hiv), and helicobacter pylori and should be considered in the differential diagnosis of immune thrombocytopenic purpura ( ...200919245929
epidermal growth factor receptor activation protects gastric epithelial cells from helicobacter pylori-induced apoptosis.helicobacter pylori infection disrupts the balance between gastric epithelial cell proliferation and apoptosis, which is likely to lower the threshold for the development of gastric adenocarcinoma. h pylori infection is associated with epidermal growth factor (egf) receptor (egfr) activation through metalloproteinase-dependent release of egfr ligands in gastric epithelial cells. because egfr signaling regulates cell survival, we investigated whether activation of egfr following h pylori infectio ...200919250983
extracellular and intracellular pattern recognition receptors cooperate in the recognition of helicobacter pylori.helicobacter pylori infects half of the world's population, thereby causing significant human morbidity and mortality. the mechanisms by which professional antigen-presenting cells recognize the microbe are poorly understood.200919272387
in this issue: proteomics 6/2009.in this issue of proteomics you will find the following highlighted articles:keeping up with the lung cancersyou're in good company if you smoke and develop lung cancer. the world health organization estimates 1.2 million new cases occur every year. on the other hand, 1.1 million people die from it every year-bummer. one reason for the high death rate is the frequent development of resistance to several of the most commonly used drugs simultaneously. multiple drug resistance (mdr) is the major c ...200919294620
single nucleotide polymorphism of interleukin-1beta associated with helicobacter pylori infection in immune thrombocytopenic purpura.to examine the role of genetic factors in development of immune thrombocytopenic purpura (itp) in association with helicobacter pylori infection, gene polymorphisms within the loci for human leukocyte antigen class ii, interleukin (il)-1beta (-511), tumor necrosis factor-beta (+252), immunoglobulin (ig)g1 heavy chain (+643), and igkappa light chain (+573) were determined in 164 adults with itp and 75 healthy controls. of these gene polymorphisms, the il-1beta (-511) t allele was less frequently ...200919317746
childhood leukemias and other hematopoietic malignancies: interdependence between an infectious event and chromosomal modifications.a large number of epidemiological observations suggest an infectious origin of hematopoietic malignancies, including various forms of leukemia, nonhodgkin's lymphomas, hodgkin's lymphomas and multiple myelomas. incidence of nonhodgkin's lymphomas and hodgkin's lymphomas, although not of leukemias, is substantially increased under immunosuppression. specific chromosomal modifications (translocations) resulting in fusion genes frequently emerge as early, but not sufficient, events for malignant pr ...200919330827
an african perspective on helicobacter pylori: prevalence of human infection, drug resistance, and alternative approaches to treatment.helicobacter pylori is a gram-negative, micro-aerophilic, motile, curved rod that inhabits the gastric mucosa of the human stomach. it chronically infects thousands of millions of people world-wide, and is one of the most genetically diverse of bacterial species. infection with the bacterium leads to chronic gastritis, peptic ulceration, gastric cancers and gastric mucosa-associated lymphoid-tissue (malt) lymphoma. the prevalence of infection appears to be partly determined by geographical and s ...200919341534
helicobacter-based mouse models of digestive system carcinogenesis.animal models are necessary to reproduce the complex host, microbial and environmental influences associated with infectious carcinogenesis of the digestive system. today, mouse models are preferred by most researchers because of cost efficiencies, rapid reproduction, choice of laboratory reagents, and availability of genetically engineered mutants to study specific gene functions in vivo. mouse models have validated the once-provocative hypothesis that helicobacter pylori infection is a major r ...200919347301
an unusual mechanism of thymidylate biosynthesis in organisms containing the thyx gene.biosynthesis of the dna base thymine depends on activity of the enzyme thymidylate synthase to catalyse the methylation of the uracil moiety of 2'-deoxyuridine-5'-monophosphate. all known thymidylate synthases rely on an active site residue of the enzyme to activate 2'-deoxyuridine-5'-monophosphate. this functionality has been demonstrated for classical thymidylate synthases, including human thymidylate synthase, and is instrumental in mechanism-based inhibition of these enzymes. here we report ...200919370033
analysis of bacterial proteins by 2de.two-dimensional gel electrophoresis (2de) is a key analytical method for investigating bacterial -proteomes. the relatively simple genomes of many bacteria combined with only limited post--translational modifications of bacterial proteins mean that a significant proportion of the proteome is open to analysis by 2de. the applications of 2de in the field of microbiology are diverse and range from analysing physiological responses of the bacteria to environmental stress to investigating bacterial p ...200919381581
dual nuclease and helicase activities of helicobacter pylori addab are required for dna repair, recombination, and mouse infectivity.helicobacter pylori infection of the human stomach is associated with disease-causing inflammation that elicits dna damage in both bacterial and host cells. bacteria must repair their dna to persist. the h. pylori addab helicase-exonuclease is required for dna repair and efficient stomach colonization. to dissect the role of each activity in dna repair and infectivity, we altered the adda and addb nuclease (nuc) domains and the adda helicase (hel) domain by site-directed mutagenesis. extracts of ...200919395381
a single nucleotide change affects fur-dependent regulation of sodb in h. pylori.helicobacter pylori is a significant human pathogen that has adapted to survive the many stresses found within the gastric environment. superoxide dismutase (sodb) is an important factor that helps h. pylori combat oxidative stress. sodb was previously shown to be repressed by the ferric uptake regulator (fur) in the absence of iron (apo-fur regulation) [1]. herein, we show that apo regulation is not fully conserved among all strains of h. pylori. apo-fur dependent changes in sodb expression are ...200919399190
dual infection system identifies a crucial role for pka-mediated serine phosphorylation of the epec-tir-injected effector protein in regulating rac1 function.many gram-negative pathogenic bacteria possess type-iii or type-iv secretion systems to inject 'effector' proteins directly into host cells to modulate cellular processes in their favour. a common target is the actin-cytoskeleton linked to the delivery of a single (caga) effector by helicobacter pylori and multiple effectors by enteropathogenic escherichia coli (epec) respectively. here we report co-infection as a powerful strategy for defining effector protein function and mechanisms by which t ...200919438518
serum bactericidal activity against helicobacter pylori in patients with hypogammaglobulinaemia.the two major primary antibody deficiency disorders are x-linked hypogammaglobulinaemia (xla) and common variable immunodeficiency (cvid). cvid patients have an elevated risk for gastric cancer and extra-nodal marginal zone lymphoma. both diseases are associated with helicobacter pylori infection. we investigated whether antibody deficiency leads to defective serum bactericidal activity against h. pylori. we also investigated the correlation with immunoglobulin (ig)m levels and observed the term ...200919438595
adult onset schönlein-henoch purpura associated with helicobacter pylori infection.schönlein-henoch purpura (shp) is a systemic vasculitis, primarily involving the skin, gastrointestinal (gi) tract, joints, and kidneys. a wide variety of different conditions may be implicated in the pathogenesis of shp. we report a 33-year-old man who presented with shp accompanied by gastric helicobacter pylori (hp) infection. the gi manifestations and purpuric rashes were dramatically resolved after hp eradication therapy. to date, very few publications have focused on the possible pathogene ...200919443983
aneuploidy involving chromosome 1 may be an early predictive marker of intestinal type gastric cancer.intestinal type gastric cancer is a significant cause of mortality, therefore a better understanding of its molecular basis is required. we assessed if either aneuploidy or activity of the oncogenic transcription factor nuclear factor kappa b (nf-kappab), increased incrementally during pre-malignant gastric histological progression and also if they correlated with each other in patient samples, as they are both induced by oxygen free radicals. in a prospective study of 54 (aneuploidy) and 59 (nf ...200919481101
cdx2 expression is induced by helicobacter pylori in ags cells. 200918991163
parp-1 val762ala polymorphism, caga+ h. pylori infection and risk for gastric cancer in han chinese population.parp-1 plays important role in the ber (base excision repair) and maintenance of genomic integrity. previous study found the val762ala genetic variant in the parp-1 gene contributed to susceptibility of some cancers and decreased parp-1 enzyme activity in response to oxidative damage. helicobacter pylori (h. pylori) infection was thought to be one of the major causes of gastric cancer. in this study, we investigated the association between the parp-1 val762ala polymorphism, caga(+) h. pylori inf ...200918716896
the relationship between updated sydney system score and ldl cholesterol levels in patients infected with helicobacter pylori.helicobacter pylori (h. pylori) chronically infects the human stomach and may cause extra-gastrointestinal diseases. the role of h. pylori in the pathogenesis of atherosclerosis and its effect on lipids remains controversial. the aim of this study was to examine lipid levels in patients with and without h. pylori infection.200918649137
involvement of ras and ap-1 in helicobacter pylori-induced expression of cox-2 and inos in gastric epithelial ags cells.helicobacter pylori (h. pylori) is an important risk factor for chronic gastritis, peptic ulcer, and gastric cancer. the genetic differences of h. pylori isolates play a role in the clinical outcome of the infection. inflammatory genes including cyclooxygenase-2 (cox-2) and inducible nitric oxide synthase (inos) are involved in h. pylori gastritis. transcription factor ap-1 is composed of c-fos and c-jun and mediates inflammation and carcinogenesis. ras acts as a regulator for ap-1 activation in ...201019495976
identification of cell-surface mannans in a virulent helicobacter pylori strain.with the intent of contributing to a carbohydrate-based vaccine against the gastroduodenal pathogen, helicobacter pylori, we report here the structure of cell-surface mannans obtained from a virulent strain. unlike other wild-type strains, this strain was found to express in good quantities this polysaccharide in vitro. structural analysis revealed a branched mannan formed by a backbone of alpha-(1-->6)-linked mannopyranosyl residues with approximately 80% branching at the o-2 position. the bran ...201020227685
genetic polymorphisms in dna repair genes xpc, xpd, and xrcc4, and susceptibility to helicobacter pylori infection-related gastric antrum adenocarcinoma in guangxi population, china.genetic polymorphisms in dna repair genes may influence individual variation in dna repair capacity, which may be associated with risk of gastric antrum adenocarcinoma (gaa) related to helicobacter pylori infection. this study, including 361 gaas and 616 controls without any evidence of tumors, was designed to evaluate the association between the polymorphisms of dna repair genes xpc ala499val (rs#2228000) and lys939gln (rs#2228001), xpd lys751gln (rs#13181), and xrcc4 ala247ser (rs#3734091) and ...201020232359
high-throughput and single-cell imaging of nf-kappab oscillations using monoclonal cell lines.the nuclear factor-kappab (nf-kappab) family of transcription factors plays a role in a wide range of cellular processes including the immune response and cellular growth. in addition, deregulation of the nf-kappab system has been associated with a number of disease states, including cancer. therefore, insight into the regulation of nf-kappab activation has crucial medical relevance, holding promise for novel drug target discovery. transcription of nf-kappab-induced genes is regulated by differe ...201020233427
human primary gastric dendritic cells induce a th1 response to h. pylori.adaptive cd4 t-cell responses are important in the pathogenesis of chronic helicobacter pylori gastritis. however, the gastric antigen-presenting cells that induce these responses have not yet been identified. here we show that dendritic cells (dcs) are present in the gastric mucosa of healthy subjects and are more prevalent and more activated in the gastric mucosa of h. pylori-infected subjects. h. pylori induced gastric dcs isolated from noninfected subjects to express increased levels of cd11 ...201020237463
in vivo accumulation of helicobacter pylori products, nod1, ubiquitinated proteins and proteasome in a novel cytoplasmic structure.cell internalization and intracellular fate of h. pylori products/virulence factors in vivo by human gastric epithelium, the main target of h. pylori-induced pathologies (i.e., peptic ulcer and cancer), are still largely unknown. investigating gastric endoscopic biopsies from dyspeptic patients by means of ultrastructural immunocytochemistry, here we show that, in human superficial-foveolar epithelium and its metaplastic or dysplastic foci, h. pylori virulence factors accumulated in a discrete c ...201020300534
dual regulation by apurinic/apyrimidinic endonuclease-1 inhibits gastric epithelial cell apoptosis during helicobacter pylori infection.human apurinic/apyrimidinic endonuclease-1 (ape-1), a key enzyme involved in repair of oxidative dna base damage, is an important transcriptional coregulator. we previously reported that helicobacter pylori infection induces apoptosis and increases ape-1 expression in human gastric epithelial cells (gec). although both the dna repair activity and the acetylation-mediated transcriptional regulation of ape-1 are required to prevent cell death, the mechanisms of ape-1-mediated inhibition of infecti ...201020332233
ethnic and geographic differentiation of helicobacter pylori within iran.the bacterium helicobacter pylori colonizes the human stomach, with individual infections persisting for decades. the spread of the bacterium has been shown to reflect both ancient and recent human migrations. we have sequenced housekeeping genes from h. pylori isolated from 147 iranians with well-characterized geographical and ethnic origins sampled throughout iran and compared them with sequences from strains from other locations. h. pylori from iran are similar to others isolated from western ...201020339588
role of helicobacter pylori infection in aberrant dna methylation along multistep gastric carcinogenesis.cpg island hypermethylation is frequently found during gastric carcinogenesis. we investigated methylation profiles of p16, lox, hand1, thbd, p41arc, and apc along multistep gastric carcinogenesis and determined their association with helicobacter pylori infection. methylation levels in these six genes were evaluated in noncancerous gastric biopsy specimens using quantitative methylation-specific pcr in 459 patients with gastric cancer (gc), 137 with dysplasia, and 248 controls. controls were di ...201020345486
helicobacter pylori caga phosphorylation status determines the gp130-activated shp2/erk and jak/stat signal transduction pathways in gastric epithelial cells.the helicobacter pylori protein caga may undergo tyrosine phosphorylation following its entry into human gastric epithelial cells with downstream effects on signal transduction. disruption of the gp130 receptor that modulates the balance of the shp2/erk and jak/stat pathways enhanced peptic ulceration and gastric cancer in gp130 knock-out mice. in this study, we evaluated the effect of translocated caga in relation to its tyrosine phosphorylation status on the gp130-mediated signal switch betwee ...201020348091
[polymorphism of cytokine genes in the development of helicobacter pylori infection].the purpose of this work was to study morphological features of gastric mucosa depending on polymorphism of il-l1beta and il-1rn genes in children with chronic gastritis infected with different strains of helicobacter pylori 0. we examined 106 children with hp-associated gastritis. the results suggest association of mucosal inflammation with t allele in polymorphous c-511t locus of il-1beta (beta2 = 14,006; alpha = 0.001). aga + strains of hp were more frequently identified in patients with eros ...201020364673
angiogenesis and lymphangiogenesis of gastric cancer.tumor angiogenesis is the result of an imbalance between positive and negative angiogenic factors released by tumor and host cells into the microenvironment of the neoplastic tissue. the stroma constitutes a large part of most solid tumors, and cancer-stromal cell interactions contribute functionally to tumor growth and metastasis. activated fibroblasts and macrophages in tumor stroma play important roles in angiogenesis and tumor progression. in gastric cancer, tumor cells and stromal cells pro ...201020369064
solanum torvum inhibits helicobacter pylori growth and mediates apoptosis in human gastric epithelial cells.helicobacter pylori infection is associated with an increased risk for development of duodenal ulcers, gastric ulcers, gastric adenocarcinomas and gastric lymphomas. however, resistant strains have developed because of antibiotic treatment. in this study, the water, acetone, chloroform and methanol extracts of two solancaceae plants, solanum erianthum and solanum torvum (st), were tested for their anti-h. pylori activity. all of st extracts were able to inhibit the growth of h. pylori and showed ...201020372857
religious involvement and seroprevalence of six infectious diseases in us adults.in the united states, religious practice is inversely associated with several chronic conditions, but no reports show whether it is inversely associated with prevalence of positive serology for infections.201020375957
effects of cyp2c19, mdr1, and interleukin 1-b gene variants on the eradication rate of helicobacter pylori infection by triple therapy with pantoprazole, amoxicillin, and metronidazole.eradication of h. pylori is an important treatment strategy in peptic ulcer patients. current regimens of eradication consist of proton pump inhibitor (ppi) and two antibiotics. effects of ppi may depend on their metabolism, and other factors important for the pathophysiology of peptic ulcer disease. aim of the present study was to evaluate an association of cyp2c19, mdr1, and il-1b polymorphisms with the eradication rate of h. pylori in polish caucasian patients treated with a triple therapy of ...201020376628
the relationship between helicobacter pylori infection and gastric adenocarcinoma in northern iran.colonization of the human stomach with helicobacter pylori induces chronic gastritis and is associated with the development of gastric and duodenal ulcers, gastric carcinoma, and gastric mucosa-associated lymphoid tissue lymphoma. infection with an h. pylori strain containing the cytotoxin-associated (caga) gene (a marker for a pathogenicity island) may increase the risk of atrophic gastritis and gastric cancer. the exact role of h. pylori in gastric carcinogenesis is still being investigated. h ...201020377133
inflammatory cytokine gene polymorphisms increase the risk of atrophic gastritis and intestinal metaplasia.to investigate the effects of interleukin-8 (il-8), macrophage migration inhibitory factor (mif) gene polymorphisms, helicobacter pylori (h. pylori) infection, on the risk of developing severe chronic atrophic gastritis (scag) and intestinal metaplasia (im).201020380014
[the effect of rosiglitazone on the cell proliferation and the expressions of p27 and skp2 in helicobacter pylori infected human gastric epithelial cells].ligands for peroxisome proliferator-activated receptorgamma (ppargamma), a member of the ligand-activated nuclear receptor superfamily, exhibit anti-tumoral effects and are associated with de novo synthesis of proteins involved in regulating the cell cycle and cell survival/death. helicobacter pylori (h. pylori) is an etiologic agent for gastric adenocarcinoma, and raises the cell turnover of gastric epithelium. the aim of this study was to investigate the effect of ppargamma ligand rosiglitazon ...201020389175
defensin-mrna expression in the upper gastrointestinal tract is modulated in children with celiac disease and helicobacter pylori-positive gastritis.defensins are expressed in epithelial cells as cationic peptides with antimicrobial properties. because of their role as immunologically important effector molecules, their contribution in maintaining a stable microenvironment in the gastrointestinal tract has recently received much attention. the present study was designed to further characterize expression patterns of defensins in diseases of the upper gastrointestinal tract in children, particularly in helicobacter pylori (hp)-associated gast ...201020400909
the role of small molecular weight compounds to increase vacuolation induced by vaca toxin in vitro.vaca is a vacuolation protein toxin secreted by helicobacter pylori. many compounds have been implicated in the regulation of vaca toxin activity. in this study, regulation of cell vacuolation induced by vaca was observed with the addition of glycine, glycine hydrochloride, xylitol, and taurine by neutral red dye uptake assay using gastric human epithelial cell cultures. glycine, xylitol, and taurine increased cell vacuolation significantly after 48h (p<0.05), with their effect apparent in a wid ...201020403422
b-cell receptor signaling and cd40 ligand-independent t cell help cooperate in helicobacter-induced malt lymphomagenesis.gastric b-cell lymphoma of mucosa-associated lymphoid tissue (malt) develops in the context of chronic inflammation caused by helicobacter pylori infection. most pathophysiological features of the early stages of malt lymphomagenesis can be reproduced by experimental infection of balb/c mice with helicobacter species. we have previously shown that malt lymphomas are infiltrated by t-helper cell type 2-polarized t cells and that human and murine tumor b cells carry polyreactive surface immunoglob ...201020428202
muc1 cell surface mucin attenuates epithelial inflammation in response to a common mucosal pathogen.helicobacter pylori infection of the gastric mucosa causes an active-chronic inflammation that is strongly linked to the development of duodenal and gastric ulcers and stomach cancer. however, greater than 80% of individuals infected with h. pylori are asymptomatic beyond histologic inflammation, and it is unknown what factors influence the incidence and character of bacterial-associated gastritis and related disorders. because previous studies demonstrated that the muc1 epithelial glycoprotein ...201020430889
refractory gastric ulcer with abundant igg4-positive plasma cell infiltration: a case report.we describe a 77-year-old man with refractory gastric ulcer that worsened after helicobacter pylori eradication therapy. pathology showed marked infiltration of igg4-positive plasma cells in the gastric lesions, which led us to suspect igg4-related sclerosing disease. to the best of our knowledge, this is the first report of igg4-related gastric ulcer without the main manifestation of autoimmune pancreatitis.201020440861
[acute upper gastrointestinal bleeding after coronary intervention in acute myocardial infarction].a 73-year-old man with nstemi (non-st segment elevation myocardial infarction) underwent coronary angiography and an in-stent restenosis and thrombosis in ramus circumflexus was found. a drug-eluting stent (des) was implanted. 12 h after intervention during threefold platelet inhibition the patient presented a gastrointestinal bleeding with melena and the hemoglobin level dropped from 15.3 g/dl to 9.7 g/dl.201020455053
analysis of a beta-helical region in the p55 domain of helicobacter pylori vacuolating toxin.helicobacter pylori is a gram-negative bacterium that colonizes the human stomach and contributes to the development of gastric cancer and peptic ulcer disease. vaca, a toxin secreted by h. pylori, is comprised of two domains, designated p33 and p55. analysis of the crystal structure of the p55 domain indicated that its structure is predominantly a right-handed parallel beta-helix, which is a characteristic of autotransporter passenger domains. substitution mutations of specific amino acids with ...201020178613
drinking air and maneuvering it to the pyloric region of the stomach for the treatment for helicobacter pylori infection.helicobacter pylori is a flagellate, gram-negative bacterium which lives in the pyloric region of the human stomach and is a major cause of a large proportion of peptic ulcers, some non-ulcer dyspepsias and rarely, gastric cancers. it is a microaerophilic (anaerobic) organism. in place of the several drugs currently in use for treating h. pylori infection, plain simple atmospheric air swallowed or sucked into the stomach, or drunk by any of the various techniques described here and then postural ...201020189723
cyp2c19 genotypes in the pharmacokinetics/pharmacodynamics of proton pump inhibitor-based therapy of helicobacter pylori infection.proton pump inhibitors (ppis) are potent gastric acid inhibitors. therapies with a ppi and antibiotics are used to cure helicobacter pylori (h. pylori) infection, which is closely related to many gastrointestinal diseases. most ppis are mainly metabolized by cytochrome 2c19 (cyp2c19). the genetic polymorphisms of cyp2c19 may lead to the differences in pharmacokinetics (pk), pharmacodynamics (pd) and clinical efficacy of ppis.201019968574
helicobacter pylori stimulates dendritic cells to induce interleukin-17 expression from cd4+ t lymphocytes.helicobacter pylori is a human gastroduodenal pathogen that leads to active chronic inflammation characterized by t-cell responses biased toward a th1 phenotype. it has been accepted that h. pylori infection induces a th17 response. at mucosal sites, dendritic cells (dcs) have the capacity to induce effector t cells. here, we evaluate the role of dcs in the h. pylori-induced interleukin-17 (il-17) response. immunohistochemistry and immunofluorescence were performed on human gastric mucosal biops ...201019917709
a comparison of the acid-inhibitory effects of esomeprazole and pantoprazole in relation to pharmacokinetics and cyp2c19 polymorphism.esomeprazole and pantoprazole are metabolized in the liver and the polymorphic cyp2c19 enzyme is involved in that process. this genetic polymorphism determines fast (70% of caucasians), intermediate (25-30% of caucasians) and slow (2-5% of caucasians) metabolism of ppis.201019785625
methods to monitor autophagy in h. pylori vacuolating cytotoxin a (vaca)-treated cells.helicobacter pylori is a gram negative pathogen that infects at least half of the world's population and is associated not only with gastric cancer but also with other diseases such as gastritis and peptic ulcers. indeed, h. pylori is considered the single most important risk factor for the development of gastric cancer. the vacuolating cytotoxin vaca, secreted by h. pylori, promotes intracellular survival of the bacterium and modulates host immune responses. in a recent study, we reported that ...201019875940
differentiation of isomeric lewis blood groups by positive ion electrospray tandem mass spectrometry.lewis histo-blood group antigens are one of the major classes of biologically active oligosaccharides. in this work, underivatized lewis blood groups were studied by electrospray tandem mass spectrometry (esi-ms(n)) in the positive mode with three different mass analyzers: q-tof (quadrupole time-of-flight), qqq (triple quadrupole), and lit (linear ion trap). it was observed that, under collision-induced fragmentations, type 1 lewis antigens (le(a) and le(b)) could be distinguished from type 2 (l ...201019878643
induction of paranodal myelin detachment and sodium channel loss in vivo by campylobacter jejuni dna-binding protein from starved cells (c-dps) in myelinated nerve fibers.in an axonal variant of guillain-barré syndrome (gbs) associated with campylobacter jejuni (c. jejuni) enteritis, the mechanism underlying axonal damage is obscure. we purified and characterized a dna-binding protein from starved cells derived from c. jejuni (c-dps). this c-dps protein has significant homology with helicobacter pylori neutrophil-activating protein (hp-nap), which is chemotactic for human neutrophils through binding to sulfatide. because sulfatide is essential for paranodal junct ...201019880143
elevated serum matrix metalloproteinase-3 and -7 in h. pylori-related gastric cancer can be biomarkers correlating with a poor survival.helicobacter pylori (h. pylori) infection up-regulates the expression of matrix metalloproteinases (mmps), which may be involved in chronic inflammation, ulceration, and even cancer development. this study aimed to test if serum levels of mmp-3, -7, and -9 are correlated with different clinical outcomes in h. pylori-infected subjects and if these are predictive of progression to h. pylori-related gastric cancer.201019690958
chronic aspirin use suppresses cdh1 methylation in human gastric mucosa.there have been reports showing a protective role of aspirin and other nonsteroidal anti-inflammatory drugs (nsaids) against gastrointestinal cancers. e-cadherin (cdh1) is an adhesion molecule involved in tumour invasion/metastasis. silencing of cdh1 by promoter cpg island methylation was shown in gastric cancer, precancerous lesion, and helicobacter pylori-infected chronic gastritis. we investigated the methylation status of cdh1 in noncancerous gastric mucosa in chronic aspirin user, and asses ...201019184424
helicobacter pylori urease activates blood platelets through a lipoxygenase-mediated pathway.the bacterium helicobacter pylori causes peptic ulcers and gastric cancer in human beings by mechanisms yet not fully understood. h. pylori produces urease which neutralizes the acidic medium permitting its survival in the stomach. we have previously shown that ureases from jackbean, soybean or bacillus pasteurii induce blood platelet aggregation independently of their enzyme activity by a pathway requiring platelet secretion, activation of calcium channels and lipoxygenase-derived eicosanoids. ...201019754669
helicobacter pylori: bacterial factors and the role of cytokines in the immune response.helicobacter pylori is a gram-negative micro-aerophilic bacterium that is widely distributed geographically and causes chronic gastritis, peptic ulcers, gastric adenocarcinoma, and mucosa-associated lymphoid tissue lymphoma. bacterial virulence factors play an important role, since the virulent strains are more aggressive and increase the risk of developing severe clinical manifestations; in addition, other determinant factors are the nutritional state and the immune response of the host. studie ...201019847485
helicobacter pylori lipopolysaccharides upregulate toll-like receptor 4 expression and proliferation of gastric epithelial cells via the mek1/2-erk1/2 mitogen-activated protein kinase pathway.helicobacter pylori is recognized as an etiological agent of gastroduodenal diseases. h. pylori produces various toxic substances, including lipopolysaccharide (lps). however, h. pylori lps exhibits extremely weakly endotoxic activity compared to the typical lps, such as that produced by escherichia coli, which acts through toll-like receptor 4 (tlr4) to induce inflammatory molecules. the gastric epithelial cell lines mkn28 and mkn45 express tlr4 at very low levels, so they show very weak interl ...201019858308
late reactivation of sonic hedgehog by helicobacter pylori results in population of gastric epithelial cells that are resistant to apoptosis: implication for gastric carcinogenesis.as much as that a disturbance of tissue homeostasis through dysregulated apoptosis is generally associated with carcinogenesis, gastric carcinogenesis after helicobacter pylori infection could be the accumulated consequence of imbalances between apoptosis and proliferation. since sonic hedgehog (shh) has been reported to play versatile roles in various tumorigenesis, we hypothesized that late reactivation of sonic hedgehog by h. pylori infection results in population of gastric epithelial cells ...201019540662
helicobacter pylori and inflammation.helicobacter pylori is a spiral-shaped, flagellated, microaerophilic gram-negative bacillus which colonizes the gastric mucosa of more than 50% of human population. the chronic infection generates a state of inflammation, which however is asymptomatic in the majority of the subjects. nevertheless, in a subset of the h. pylori-infected population, the gastric inflammation may evolve toward chronic gastritis, peptic ulcer, gastric mucosa-associated lymphoid tissue (malt) lymphoma, and gastric canc ...201021184659
biochemical studies on helicobacter pylori arginase: insight into the difference in activity compared to other arginases.arginase is a binuclear mn(2+)-metalloenzyme of urea cycle that catalyzes the conversion of l-arginine to l-ornithine and urea. unlike other arginases, the helicobacter pylori enzyme is selective for co(2+), and has lower catalytic activity. to understand the differences in the biochemical properties as well as activity compared to other arginases, we carried out a detailed investigation of different metal reconstituted h. pylori arginases that includes steady-state kinetics, fluorescence measur ...201021190293
optimizing the growth of stressed helicobacter pylori.helicobacter pylori is a gram-negative bacterium that colonizes the human stomach and is responsible for causing gastric ulcers. h. pylori is known to become stressed and nonculturable after exposure to unfavorable conditions. in this study, we enhanced previously published resuscitation procedures, characterized conditions under which stressed h. pylori can be recovered, and formulated a selective and differential resuscitation medium. results showed that a specialized broth supplemented with t ...201021129415
helicobacter pylori affects the cellular deubiquitinase usp7 and ubiquitin-regulated components traf6 and the tumour suppressor p53.helicobacter pylori is a recognized cancerogenic bacterial agent in humans, associated with gastritis, peptic ulcer, and gastric cancer. immunoevasive and immunomodulatory mechanisms underlie the chronic persistence of the bacterium and the active proinflammatory effect of life-long h. pylori infection. in contrast to tumorigenic viruses, which frequently possess factors to influence the host ubiquitin-proteasome system (ups), nothing is yet known about potential effects of h. pylori in this res ...201021131231
personalized treatment in the eradication therapy for helicobacter pylori.helicobacter pylori (hp) is known to be a causative bacterium of gastritis and peptic ulcers. the combination treatment consisting of a proton pump inhibitor (ppi), amoxicillin and clarithromycin (cam) is widely used in eradication therapy, but the eradication fails in some patients. the main causes are cam resistance of hp and individual variability in ppi metabolism related to the activity of the cytochrome p450 2c19 (cyp2c19) enzyme. in this study, we examined the usefulness of the prediction ...201021132257
runx3 methylation and expression associated with advanced precancerous gastric lesions in a chinese population.runt-related transcription factor 3 (runx3) is a tumor suppressor of gastric cancer. our study aimed to investigate the correlation of runx3 methylation, expression and the risk of advanced gastric lesions, based on a high-risk population in linqu county, shandong province, china. methylation status of runx3 was determined by methylation-specific polymerase chain reaction, and expression was detected by immunohistochemical analysis in 1113 subjects with different gastric lesions. results showed ...201021135153
cdx2 autoregulation in human intestinal metaplasia of the stomach: impact on the stability of the phenotype.intestinal metaplasia (im) is a gastric preneoplastic lesion that appears following helicobacter pylori infection and confers an increased risk for development of cancer. it is induced by gastric expression of the intestine-specific transcription factor cdx2. the regulatory mechanisms involved in triggering and maintaining gastric cdx2 expression have not been fully elucidated. the cdx2(+/-) mouse develops intestinal polyps with gastric differentiation and total loss of cdx2 expression in the ab ...201021148572
vitamin b(6) is required for full motility and virulence in helicobacter pylori.despite recent advances in our understanding of how helicobacter pylori causes disease, the factors that allow this pathogen to persist in the stomach have not yet been fully characterized. to identify new virulence factors in h. pylori, we generated low-infectivity variants of a mouse-colonizing h. pylori strain using the classical technique of in vitro attenuation. the resulting variants and their highly infectious progenitor bacteria were then analyzed by global gene expression profiling. the ...201021151756
the gastrointestinal aspects of halitosis.halitosis is a common human condition for which the exact pathophysiological mechanism is unclear. it has been attributed mainly to oral pathologies. halitosis resulting from gastrointestinal disorders is considered to be extremely rare. however, halitosis has often been reported among the symptoms related to helicobacter pylori infection and gastroesophageal reflux disease.201021152460
partial regression of duodenal lesions of intestinal follicular lymphoma after antibiotic treatment.a 51-year-old man was referred to our hospital because of duodenal lesions of lymphoma. endoscopy showed multiple tiny smooth whitish granules in the second portion of the duodenum including the papilla of vater. biopsy specimens showed medium-sized centrocyte-like cells forming lymphoid follicles, and immunohistology showed positive staining for bcl-2 and cd10. a small bowel series showed multiple granular lesions extending from the second portion of the duodenum to the proximal jejunum and the ...201021175486
helicobacter pylori defines local immune response through interaction with dendritic cells.the bacterial pathogen helicobacter pylori colonizes the human gastric and duodenal mucosa, evades clearance by the host response and is associated with peptic ulcer disease and an increased risk of gastric adenocarcinoma. dendritic cells (dcs) are initiators of the immune response to h. pylori. the aim of the current study was to investigate the interaction between h. pylori with dcs. to determine the impact of h. pylori on the maturation and the activation of monocyte-derived dcs, the effect o ...201021175878
the dual therapy with 4 times daily dosing of rabeprazole and amoxicillin as the 3rd rescue regimen for eradication of h. pylori.most of patients who are refractory to usual standard eradication therapies for h. pylori infection have rapid metabolizer genotype of cyp2c19 and are infected with resistant strains to several antimicrobial agents. however, most of h. pylori strains are sensitive to amoxicillin. we tested whether dual therapy with the 4 times daily dosing of rabeprazole and amoxicillin was effective as the 3rd rescue regimen for eradication of h. pylori.201021410079
helicobacter pylori infection, oncogenic pathways and epigenetic mechanisms in gastric carcinogenesis.chronic colonization of the human stomach by helicobacter pylori, a gram-negative bacterium, is the major cause of chronic gastritis, peptic ulcers and gastric cancer. recent progress has elucidated important bacterial and host factors that are responsible for h. pylori-induced gastric inflammation and gastric malignancy. h. pylori cytotoxin-associated antigen a is the major oncogenic factor injected into host cells from bacteria and it disrupts epithelial cell functions. together with h. pylori ...201020465395
peptidoglycan crosslinking relaxation promotes helicobacter pylori's helical shape and stomach colonization.the mechanisms by which bacterial cells generate helical cell shape and its functional role are poorly understood. helical shape of the human pathogen helicobacter pylori may facilitate penetration of the thick gastric mucus where it replicates. we identified four genes required for helical shape: three lytm peptidoglycan endopeptidase homologs (csd1-3) and a ccma homolog. surrounding the cytoplasmic membrane of most bacteria, the peptidoglycan (murein) sacculus is a meshwork of glycan strands j ...201020510929
helicobacter pylori caga and vaca genotypes in cuban and venezuelan populations.the aim of this study was to determine the presence of helicobacter pylori cytotoxin-associated gene (caga)/vacuolating cytotoxin gene (vaca) among patients with chronic gastritis in cuba and venezuela. gastric antrum biopsies were taken for culture, dna extraction and pcr analysis. amplification of vaca and caga segments was performed using two regions of caga: 349 bp were amplified with the f1/b1 primers and the remaining 335 bp were amplified with the b7629/b7628 primers. the va1-f/va1-r set ...201020512250
differential expression of nf-kappab target genes in malt lymphoma with and without chromosome translocation: insights into molecular mechanism.mucosa-associated lymphoid tissue (malt) lymphoma is characterized by t(11;18)(q21;q21)/api2-malt1, t(1;14)(p22;q32)/bcl10-igh and t(14;18)(q32;q21)/igh-malt1, which commonly activate the nuclear factor (nf)-kappab pathway. gastric malt lymphomas harboring such translocations usually do not respond to helicobacter pylori eradication, while most of those without translocation can be cured by antibiotics. to understand the molecular mechanism of these different malt lymphoma subgroups, we performe ...201020520640
methylation status of cdh1 gene in samples of gastric mucous from brazilian patients with chronic gastritis infected by helicobacter pylori.gastric cancer is one of the top list of cancer types that most leads to death in brazil and worldwide. helicobacter pylori(h. pylori) is a class i carcinogen and infect almost 90% of chronic gastritis patients. some genotypes confer different virulent potential to h. pylori and can increase the risk of gastritis development. methylation of cpg islands can inactivate tumor suppressor genes and therefore, it can be involved in the tumorigenic process. cdh1 is a tumor suppressor gene that encodes ...201020520968
sox2 in gastric carcinoma, but not hath1, is related to patients' clinicopathological features and prognosis.sox2 and hath1 are transcription factors that are critical for the control of terminal cell differentiation in the gastrointestinal mucosa. this study investigated the correlations between sox2 and hath1 expression in gastric carcinoma and patients' clinicopathological features and prognosis.201020532662
helicobacter pylori dupa is polymorphic, and its active form induces proinflammatory cytokine secretion by mononuclear cells.infection with helicobacter pylori possessing a newly described virulence factor--duodenal ulcer-promoting gene a (dupa)--has been associated with duodenal ulceration and increased gastric inflammation.201020533870
up-regulated microrna-146a negatively modulate helicobacter pylori-induced inflammatory response in human gastric epithelial cells.helicobacter pylori (h. pylori) is a major human pathogenic bacterium in gastric mucosa. however, the regulatory mechanism of h. pylori-induced immune response is not clear. micrornas (mirnas) have recently emerged as key post-transcriptional regulators of gene expression, and their role in h. pylori infection is just beginning to be explored. here, we first reported that h. pylori infection up-regulated the expression of mir-146a in gastric epithelial cells as well as in gastric mucosal tissues ...201020542134
regulation of p53 tumor suppressor by helicobacter pylori in gastric epithelial cells.infection with the gastric mucosal pathogen helicobacter pylori is the strongest identified risk factor for distal gastric cancer. these bacteria colonize a significant part of the world's population. we investigated the molecular mechanisms of p53 regulation in h pylori-infected cells.201020547161
the food glycome: a source of protection against pathogen colonization in the gastrointestinal tract.trillions of microbes inhabit the gastrointestinal tract of humans with significant differences in the composition and distribution of intestinal flora along its length. normally there is a symbiotic relationship between the intestinal microflora and the host, with mutual advantages for both partners. when this relationship is altered, commensal bacteria can rapidly shift toward pathogenicity resulting in the onset and progression of gastrointestinal infection. pathogen adhesion and colonization ...201020580113
helicobacter pylori potentiates epithelial:mesenchymal transition in gastric cancer: links to soluble hb-egf, gastrin and matrix metalloproteinase-7.helicobacter pylori (h pylori) infection is a major risk factor in the development of distal gastric adenocarcinoma. development of the invasive phenotype is associated with the phenomenon of epithelial:mesenchymal transition (emt). soluble heparin-binding epidermal growth factor (hb-egf) has been implicated in this process. a study was undertaken to investigate the possibility that matrix metalloproteinase (mmp)-7 is upregulated in h pylori infection as a result of hypergastrinaemia, which may ...201020584780
the role of environmental factors in autoimmune thyroiditis.environmental factors can play an important role in the development of autoimmune thyroiditis (at) and other autoimmune diseases. this article reviews the role of heavy metals and infectious agents in at. currently, the genes responsible for a metal-induced pathology are known in experimental animals but similar knowledge is lacking in man. metals such as nickel or mercury induce delayed type t cell hypersensitivity (allergy) which is relatively common, especially in women. t-cell allergy can be ...201020588228
gastric and intestinal barrier impairment in tropical enteropathy and hiv: limited impact of micronutrient supplementation during a randomised controlled trial.although micronutrient supplementation can reduce morbidity and mortality due to diarrhoea, nutritional influences on intestinal host defence are poorly understood. we tested the hypothesis that micronutrient supplementation can enhance barrier function of the gut.201020604937
rabeprazole can overcome the impact of cyp2c19 polymorphism on quadruple therapy.the prospective study was designed to clarify the impact of cyp2c19 on quadruple therapies and survey the efficacies of rabeprazole-based quadruple therapy for helicobacter pylori infection after failure of standard triple therapies.201020633187
promoter methylation status of multidrug resistance 1 (mdr1) gene in noncancerous gastric mucosa correlates with helicobacter pylori infection and gastric cancer occurrence.we investigated the methylation status of multidrug resistance 1 (mdr1) gene promoter in noncancerous gastric mucosa in relation to gastric cancer (gc) occurrence. methylation of the mdr1 promoter was estimated in 127 gc and 82 non-gc patients. a significant association was found between higher methylation ratio and occurrence of gc. higher methylation ratio was also associated with occurrence of gc in both helicobacter pylori-positive and helicobacter pylori-negative subjects. higher mr was als ...201020636108
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