Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| 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 ... | 2001 | 11309113 |
| 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 ... | 2001 | 11289148 |
| 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 ... | 2001 | 11283050 |
| 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 ... | 2001 | 11283030 |
| 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 ... | 2001 | 11270796 |
| 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 ... | 2001 | 11256980 |
| 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 ... | 2001 | 11251969 |
| mechanism underlying post-infectious motility disorders. | 2000 | 11245301 | |
| helicobacter pylori and non-steroidal anti-inflammatory drugs. | 2000 | 11245298 | |
| 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 ... | 2001 | 11244046 |
| 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 ... | 2001 | 11241458 |
| 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- ... | 2001 | 11237830 |
| chemistry and function of vegetable polyphenols with high molecular weights. | structure and function of polypehnols with high molecular weights (tannins) were briefly reviewed to better understand the significance of polyphenol-rich foods and beverages. in a survey of bioactive ellagiannins with a macrocyclic structure and/or a gluconic acid core, some new oligomeric ellagitannins (eucarpanins and elaeagnatins) have been found in species of myrtaceae and elaeagnaceae, and their structures were elucidated by spectroscopic and chemical methods. cytotoxic activity against hu ... | 2000 | 11237170 |
| [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. | 2001 | 11218778 |
| [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. ... | 2001 | 11218411 |
| [discussions on problems in chemotherapy at the vii national russian congress "man and drug"]. | 2000 | 11212496 | |
| 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 ... | 2001 | 11207625 |
| 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 ... | 2001 | 11207617 |
| does eradication of helicobacter pylori reverse atrophic gastritis or intestinal metaplasia? data from japan. | in japan, more reports showing improvement of atrophy or im after eradication have appeared than reports showing no change. many authors take biopsy specimens from the lesser and greater curvatures of the antrum and body and incisura angularis and make a histologic assessment using the standardized updated sydney system. sampling errors should be taken into account, however. interobserver agreement is poor in grading of atrophy. apart from these problems, it seems almost certain that some patien ... | 2000 | 11190067 |
| ph-dependent protein profiles of helicobacter pylori analyzed by two-dimensional gels. | helicobacter pylori survives transient exposure to extreme acid prior to adherence and growth on the gastric epithelium at neutral ph. | 2000 | 11179990 |
| 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 ... | 2001 | 11176076 |
| 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 ... | 2001 | 11163025 |
| 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 ... | 2001 | 11160160 |
| [genomic structure of helicobacter pylori and its pathogenecity]. | 2000 | 11155709 | |
| 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 ... | 2001 | 11148003 |
| resolution of syndrome x after eradication of virulent caga-positive helicobacter pylori. | a 42-year-old man with chest pain was found to have st depression in leads v1 through v4. the coronary arteries appeared normal on angiography. positive results of ventricular pacing and acetylcholine test led to a diagnosis of syndrome x. other studies revealed gastritis due to caga-positive helicobacter pylori. classic therapy for angina did not resolve chest pain, but eradication of h. pylori led to disappearance of symptoms and negative test results. | 2000 | 11147468 |
| characteristics of helicobacter pylori attachment to human primary antral epithelial cells. | conventional cell lines are commonly used to study infection characteristics of the human gastric pathogen helicobacter pylori. we sought to investigate bacterial attachment to human antral primary epithelial cells, a cell model that more closely resembles the human stomach than transformed cell lines. primary cells were infected for 24 and 48 h with h. pylori. morphological appearance of both the pathogen and the cells as well as features of colonization, attachment and internalization were eva ... | 2000 | 11137040 |
| up-regulation of the il-12 receptor beta 2 chain in crohn's disease. | crohn' s disease (cd) is a chronic intestinal inflammatory disorder characterized by aberrant mucosal th1 cell activation and production of il-12, the major th1-driving factor. the t cell response to il-12 is dependent on the expression of a specific receptor composed of two subunits, termed il-12rbeta1 and il-12rbeta2. the content of il-12rbeta2, as measured at the mrna level, is crucial in regulating th1 differentiation. in this study we therefore investigated il-12rbeta2 rna transcripts in cd ... | 2000 | 11120856 |
| a high molecular mass constituent of cranberry juice inhibits helicobacter pylori adhesion to human gastric mucus. | because previous studies have shown that a high molecular mass constituent of cranberry juice inhibited adhesion of escherichia coli to epithelial cells and coaggregation of oral bacteria, we have examined its effect on the adhesion of helicobacter pylori to immobilized human mucus and to erythrocytes. we employed three strains of h. pylori all of which bound to the mucus and agglutinated human erythrocytes via a sialic acid-specific adhesin. the results showed that a high molecular mass constit ... | 2000 | 11118911 |
| an assessment of the long-term preservation of the dna of a bacterial pathogen in ethanol-preserved archival material. | to examine the potential for dna recovery from spirit-preserved medical material, a set of specimens from the hunterian collection of the royal college of surgeons was investigated. using a range of dna extraction techniques and the pcr, no replicable positive amplifications were made from this material of either human or helicobacter dna. experiments with modern stomach biopsies of h. pylori-positive patients suggest that the bacterial dna is typically present in a much lower concentration (10( ... | 2000 | 11113876 |
| detection of chlamydia pneumoniae and helicobacter pylori dna in human atherosclerotic plaques by pcr. | chlamydia pneumoniae and helicobacter pylori can cause persistent infections of the respiratory and gastrointestinal tract, respectively. it has been suggested that persistent infection of arteries with these bacteria can contribute to the development of atherosclerosis. the aims of this study were to determine the presence of c. pneumoniae and h. pylori dna in atherosclerotic plaque samples by pcr and to evaluate the correlation between clinical status and dna positivity of these bacteria. eigh ... | 2000 | 11101572 |
| the n-terminal 34 kda fragment of helicobacter pylori vacuolating cytotoxin targets mitochondria and induces cytochrome c release. | the pathogenic bacterium helicobacter pylori produces the cytotoxin vaca, which is implicated in the genesis of gastric epithelial lesions. by transfect ing hep-2 cells with dnas encoding either the n-terminal (p34) or the c-terminal (p58) fragment of vaca, p34 was found localized specifically to mitochondria, whereas p58 was cytosolic. incubated in vitro with purified mitochondria, vaca and p34 but not p58 translocated into the mitochondria. microinjection of dnas encoding vaca-gfp and p34-gfp, ... | 2000 | 11101509 |
| [multilocular fixed drug reaction simulating intertrigo in a diabetic patient]. | a 57-year-old man with diabetes and hypertension was treated with amoxycillin, clarithromycin and pantoprazole for a gastric ulcer positive for helicobacter pylori. on the second treatment day he developed inguinal pruritus with erythema. he presented at out-patient clinic on the 5th day suspected of having candida intertrigo. he had bright red, relatively well-circumscribed erythema, most marked at the edges, mainly over the inguinal region and the inside of the thigh. there were no other sympt ... | 2000 | 11098237 |
| cxc chemokines gro(alpha)/il-8 and ip-10/mig in helicobacter pylori gastritis. | infection with helicobacter pylori causes chronic active gastritis, which is characterized by neutrophils infiltrating the gastric epithelial layer and the underlying lamina propria as well as by t, b lymphocytes and macrophages accumulating in the lamina propria. in this study, the chemokine profile responsible for the recruitment of these inflammatory cells is investigated. using both rna/rna in situ hybridization and immunohistochemistry, the expression of the neutrophil and/or lymphocyte-att ... | 2000 | 11091274 |
| expression of cyclooxygenase-2 and nitrotyrosine in human gastric mucosa before and after helicobacter pylori eradication. | to determine whether cure of helicobacter pylori infection influences the expression of cox-2 and nitrotyrosine in the distal stomach of humans, biopsy specimens were examined immunohistochemically. h. pylori infection was determined using a rapid urease test, culture and histology. positive staining of cox-2/nitrotyrosine in the epithelium was expressed as the percentage of stained cells to the total epithelial cells. there was a significant increase in cox-2/nitrotyrosine staining in h. pylori ... | 2000 | 11090259 |
| structure of lamina propria lymphoid follicles and associated epithelium in the gastric mucosa during helicobacter pylori infection in ulcer-bearing mongolian gerbils. | to develop a gerbil model of helicobacter pylori-induced chronic active gastritis comparable in severity to human lesions, we made acetic acid-induced ulcer in the anterior antral wall and concurrently challenged 1 x 10(8) colony-forming units bacteria per os. at 30 and 60 days after inoculation, the number of viable bacteria colonizing on the surface epithelium of the gastric mucosa was larger in ulcer-bearing animals compared to non-bearing ones. furthermore, in the former animals, neutrophil ... | 2000 | 11085204 |
| helicobacter pylori infection: augmentation of telomerase activity in cancer and noncancerous tissues. | telomerase adds hexameric repeats of 5'-ttaggg-3' to the ends of chromosomal dna (telomere) and has been implicated in cell immortalization and cellular senescence. the aim of this study was to measure quantitatively the telomerase activity and human telomerase rna component (htr) content in gastric cancer and to examine the relation between these values and histologic factors including helicobacter pylori as a risk factor for gastric cancer. telomerase activity was measured by a modified telome ... | 2000 | 11071470 |
| diet and duodenal ulcer. | despite the fact that the main cause of duodenal ulcer incidence and recurrence is the helicobacter pylori bacterium, more than 80% of helicobacter pylori-infected people never develop an ulcer. diet may be one of the most important environmental factors contributing to duodenal ulcer. | 2000 | 11057920 |
| helicobacter pylori cag pathogenicity island is associated with enhanced interleukin-8 expression in human gastric mucosa. | in vitro studies showed that helicobacter pylori strains carrying the cag pathogenicity island are able to induce epithelial secretion of interleukin-8. | 2000 | 11057919 |
| review article: helicobacter pylori: where are we and where are we going? | this paper contains a personal view on what has been achieved in helicobacter pylori research and what the expectations might be for further developments. knowledge about the organism is already extensive. particularly intriguing are the differences in genetic make-up in the various geographical regions. sadly, detailed knowledge on how the organism spreads is still lacking. the clinical spectrum of the disease in man is largely known, but as h. pylori is disappearing worldwide, the relative fre ... | 2000 | 11050488 |
| effects of helicobacter pylori in the stomach on neutrophil chemiluminescence in patients with gastric cancer. | hypochlorous acid, which is one of the reactive oxgen species (ros) produced from human neutrophils, is converted to cytotoxic nh(2)cl after reaction with ammonia produced by urease in helicobacter pylori (hp), increasing gastric mucosal injury and with potential development to gastric cancer. we compared the effects of hp on the production of ros by human neutrophils between two groups-22 patients with gastric cancer and 16 patients without gastric cancer (control group), in whom hp was isolate ... | 2000 | 11038483 |
| [epidemiology, acquisition and transmission of helicobacter pylori]. | helicobacter pylori infection is a chronic infection essentially acquired during childhood. its prevalence in developed countries like france has decreased according to the year of birth all along the twentieth century, reflecting the progressive improvement of socio-economic and environmental conditions. the incidence of acquisition in adulthood is lower than 0.5% per year. in developing countries, the prevalence is still very high, even in early childhood. h. pylori is a strictly human bacteri ... | 2000 | 11019631 |
| helicobacter pylori: clonal population structure and restricted transmission within families revealed by molecular typing. | helicobacter pylori infects up to 50% of the human population worldwide. the infection occurs predominantly in childhood and persists for decades or a lifetime. h. pylori is believed to be transmitted from person to person. however, tremendous genetic diversity has been reported for these bacteria. in order to gain insight into the epidemiological basis of this phenomenon, we performed molecular typing of h. pylori isolates from different families. fifty-nine h. pylori isolates from 27 members o ... | 2000 | 11015377 |
| cyp2c19 genotype status and intragastric ph during dosing with lansoprazole or rabeprazole. | cyp2c19 has an important role in the catabolism of several proton pump inhibitors. however, the relative contribution of cyp2c19-mediated metabolism varies among the different proton pump inhibitors. | 2000 | 11012469 |
| salivary agglutinin, which binds streptococcus mutans and helicobacter pylori, is the lung scavenger receptor cysteine-rich protein gp-340. | salivary agglutinin is a high molecular mass component of human saliva that binds streptococcus mutans, an oral bacterium implicated in dental caries. to study its protein sequence, we isolated the agglutinin from human parotid saliva. after trypsin digestion, a portion was analyzed by matrix-assisted laser/desorption ionization time-of-flight mass spectrometry (maldi-tof ms), which gave the molecular mass of 14 unique peptides. the remainder of the digest was subjected to high performance liqui ... | 2000 | 11007786 |
| influence of smoking and helicobacter pylori on gastric phospholipids. | smokers show higher rates of peptic ulcer disease (pud) than nonsmokers, probably due to detrimental effects on the gastric mucosa. surface-active phospholipids (spl) are believed to play a key part in gastric cytoprotection. the aim of this study was to determine the chronic effects of smoking on the gastric spl and to relate them to h. pylori (hp) -induced effects. gastric juice was aspirated in 52 patients, with normal findings at planned upper gastrointestinal endoscopy, and concentrations o ... | 2000 | 11007119 |
| synthesis of mono- and di-fucosylated type i lewis blood group antigens by helicobacter pylori. | the identification of helicobacter pylori isolates that expresses exclusively type i lewis antigens is necessary to determine the biosynthetic pathway of these antigens. fast-atom bombardment ms provides evidence that the h. pylori isolate ua1111 expresses predominantly leb, with h type i and lea in lesser amounts. cloning and expression of the h. pylori fucosyltransferases (fucts) allow comparisons with previously identified h. pylori enzymes and determination of the enzyme specificities. altho ... | 2000 | 10998067 |
| quantitative analysis of helicobacter pylori infection in a mouse model. | progress in elucidating the pathogenesis of helicobacter pylori gastric infection and in developing an h. pylori vaccine will be aided by an animal model in which h. pylori can be reliably detected. to validate the use of the mouse model of h. pylori infection, we determined the susceptibility of three inbred strains of mice (c57bl/6j, c57bl/10j and balb/c) to two vaca+/caga+ isolates of h. pylori (spm326 and m1.16) and determined the effectiveness of microbiological, histological and molecular ... | 2000 | 10986390 |
| helicobacter pylori: an emerging infectious disease. | helicobacter pylori is the most common chronic bacterial infection in the world, colonizing the stomachs of more than 50% of the human population. the discovery of this bacterium has changed the concept of care and management for peptic ulcer disease, mucosa-associated lymphomas, gastritis, and gastric carcinoma. although the mode of transmission is not definitively known, person-to-person contact is suspected. this article discusses h. pylori, the associated clinical syndromes and diseases, ris ... | 2000 | 10971934 |
| characterization of a culture method to recover helicobacter pylori from the feces of infected patients. | helicobacter pylori is difficult to culture from stool. multiple efforts from multiple laboratories have been unsuccessful, and the optimal conditions to recover h. pylori from stool are still not known. recovery of h. pylori from feces of infected individuals is important for the performance of molecular epidemiological investigations, especially in children, where their symptoms do not warrant endoscopy to recover the organism. | 2000 | 10971682 |
| helicobacter pylori entry into human gastric epithelial cells: a potential determinant of virulence, persistence, and treatment failures. | intracellular location of helicobacter pylori in human gastric epithelial cells has been observed in biopsies. whether this reflects an ability to invade host cells and establish an intracellular niche remains to be determined. | 2000 | 10971679 |
| purification and characterization of cytochrome c-553 from helicobacter pylori. | helicobacter pylori, a microaerophilic gram-negative spiral bacterium residing in the human stomach, contains a small size soluble cytochrome c. this cytochrome c was purified from the soluble fraction of h. pylori by conventional chromatographies involving octyl-cellulose and cm-toyopearl. its reduced form gave an alpha absorption band at 553 nm, and thus the cytochrome was named h. pylori cytochrome c-553. the cytochrome, giving a band below 10,000 da upon sds-page, was determined to have a ma ... | 2000 | 10965034 |
| significant increase in antigastric autoantibodies in a long-term follow-up study of h. pylori gastritis. | in 30% of h. pylori-infected patients a certain type of antigastric autoantibodies, reacting against canalicular structures within human parietal cells, is detectable. furthermore, it has been shown that these autoantibodies are correlated with atrophy of the mucosa in the corpus. the aim of this study was to analyse the prevalence of these anticanalicular autoantibodies (acab) and their significance for development of gastric mucosa atrophy in a 12-year follow-up period. gastric biopsy specimen ... | 2000 | 10963378 |
| deletion 7p in gastric malt lymphoma. | deletion of the long arm of chromosome 7 has been related to loss of tumor suppressor genes which may constitute a primary step of carcinogenesis in many kinds of malignancies, including low-grade b-cell lymphoma. however, deletion of the short arm of chromosome 7, del(7p), in low-grade b-cell lymphoma has not been reported. here, we report a case of gastric malt lymphoma with the chromosome aberration del(7p) which progressed in spite of eradication of helicobactor pylori. deletion 7p may repre ... | 2000 | 10958947 |
| serologic and histopathologic study of chlamydia pneumoniae infection in atherosclerosis: a possible pathogenetic mechanism of atherosclerosis induced by chlamydia pneumoniae. | chronic infection and inflammation have recently been implicated as important etiologic agents for atherosclerosis in general and, in particular, ischemic heart disease. several agents have been suggested as possible candidates for the chronic inflammation including cytomegalovirus, helicobacter pylori and chlamydia pneumoniae. we hypothesized that a vascular infection with c. pneumoniae may induce a chronic inflammatory reaction in the host vascular tissue and activated inflammatory cells may e ... | 2000 | 10957885 |
| effect of helicobacter pylori on polymorphonuclear leukocyte migration across polarized t84 epithelial cell monolayers: role of vacuolating toxin vaca and cag pathogenicity island. | helicobacter pylori infection can induce polymorphonuclear leukocyte (pmnl) infiltration of the gastric mucosa, which characterizes acute chronic gastritis. the mechanisms underlying this process are poorly documented. the lack of an in vitro model has considerably impaired the study of transepithelial migration of pmnl induced by h. pylori. in the present work, we used confluent polarized monolayers of the human intestinal cell line t84 grown on permeable filters to analyze the epithelial pmnl ... | 2000 | 10948148 |
| expression of human telomerase catalytic subunit gene in cancerous and precancerous gastric conditions. | telomerase activity is thought to be necessary for cellular immortality and carcinogenesis. the mrna that encodes the telomerase catalytic subunit (htert) has recently been identified, and expression of htert mrna is thought to regulate activation of telomerase. to determine at what stage of carcinogenesis cells begin to express htert, we analysed htert mrna expression in gastric carcinoma and precancerous conditions, focusing on chronic gastritis with or without intestinal metaplasia. | 2000 | 10937679 |
| the human gastric colonizer helicobacter pylori: a challenge for host-parasite glycobiology. | the gram-negative bacterium helicobacter pylori was first described in 1983 and currently represents one of the most active single research topics in biomedicine. it is specific for the human stomach and chronically colonizes a majority of the global population, which results in a symptom-free local inflammation. in 10-20% of carriers, gastroduodenal disease develops, including gastric or duodenal ulcer, and atrophic gastritis, which is a precondition to gastric cancer. a probable long coevoluti ... | 2000 | 10929002 |
| helicobacter pylori urease binds to class ii mhc on gastric epithelial cells and induces their apoptosis. | infection by helicobacter pylori leads to injury of the gastric epithelium and a cellular infiltrate that includes cd4+ t cells. h. pylori binds to class ii mhc molecules on gastric epithelial cells and induces their apoptosis. because urease is an abundant protein expressed by h. pylori, we examined whether it had the ability to bind class ii mhc and induce apoptosis in class ii mhc-bearing cells. flow cytometry revealed the binding of pe-conjugated urease to class ii mhc+ gastric epithelial ce ... | 2000 | 10925273 |
| [decreasing prevalence of helicobacter pylori: a consequence of treatment of gastroduodenal ulcers]. | four patients with gastroduodenal ulcers in the absence of helicobacter pylori illustrate the decreasing prevalence of this microorganism. one was a 19-year-old boy with nausea, diarrhoea and weight loss caused by multiple gastroduodenal ulcers due to the zollinger-ellison syndrome. another was a 36-year-old man with abdominal discomfort caused by an ulcer due to crohn's disease. the other two cases concerned a 29-year-old man and a 68-year-old woman with relapsing ulcer disease and active bleed ... | 2000 | 10923145 |
| infections, atherosclerosis, and coronary heart disease. | there is growing evidence that the immune response is involved in atherosclerosis. studies done over the past several years have shown an association between markers of inflammation and coronary atherosclerosis with an exacerbation of the inflammatory process during acute myocardial ischemia. overall, these data have greatly renewed interest in the infectious theory of atherosclerosis and coronary heart disease. search of bibliographic databases (from january 1991 through december 1999) and manu ... | 2000 | 10920505 |
| adherence of isogenic flagellum-negative mutants of helicobacter pylori and helicobacter mustelae to human and ferret gastric epithelial cells. | isogenic flagellum-negative mutants of helicobacter pylori and helicobacter mustelae were screened for their ability to adhere to primary human and ferret gastric epithelial cells, respectively. we also evaluated the adherence of an h. pylori strain with a mutation in the flba gene, a homologue of the flbf/lcrd family of genes known to be involved in the regulation of h. pylori flagellar biosynthesis. h. pylori and h. mustelae mutants deficient in production of flaa or flab and mutants deficient ... | 2000 | 10858255 |
| anti-adhesive activity of sulphated exopolysaccharides of microalgae on attachment of red sore disease-associated bacteria and helicobacter pylori to tissue culture cells. | because of the affinity of certain bacterial species for sulphated glycoconjugates exposed on the epithelial cells of susceptible hosts, we hypothesized that sulphated exopolysaccharides of microalgae can be used in anti-adhesive therapies against bacterial infections, both in cold- and warm-blooded animals. in this study we found that adhesion of the human pathogen helicobacter pylori to the hela s3 cell line, and adhesion of the fish pathogens vibrio campbellii, v. ordalii, streptococcus sapro ... | 2000 | 10849279 |
| bcl10 gene mutation in lymphoma. | bcl10 is directly involved in t(1;14)(p22;q32) of mucosa-associated lymphoid tissue (malt) lymphoma. wild-type bcl10 promoted apoptosis and suppressed malignant transformation in vitro, whereas truncated mutants lost the pro-apoptotic activity and exhibited gain of function enhancement of transformation. we studied 220 lymphomas for genomic bcl10 mutation by polymerase chain reaction-single-strand conformational polymorphism and dna sequencing. nineteen mutations were found in 13 lymphoma specim ... | 2000 | 10845924 |
| biotransformation of glycyrrhizin by human intestinal bacteria and its relation to biological activities. | the relationship between the metabolites of glycyrrhizin (18beta-glycyrrhetinic acid-3-o-beta-d-glucuronopyranosyl-(1-->2)-beta-d-glucuronide, gl) and their biological activities was investigated. by human intestinal microflora, gl was metabolized to 18beta-glycyrrhetinic acid (ga) as a main product and to 18beta-glycyrrhetinic acid-3-o-beta-d-glucuronide (gamg) as a minor product. the former reaction was catalyzed by eubacterium l-8 and the latter was by streptococcus lj-22. among gl and its me ... | 2000 | 10836746 |
| presentation and management of helicobacter pylori infection in childhood. | helicobacter pylori is responsible for one of the most frequently encountered infectious diseases worldwide. helicobacter pylori infection can lead to the development of gastritis and peptic ulcer disease. the presence of helicobacter pylori in the human stomach also represents an increased risk of gastric cancer and gastric lymphoma. epidemiological data obtained in adults suggest that the actual colonization with helicobacter pylori is in fact determined by childhood factors. therefore, the pe ... | 1996 | 10830008 |
| advances in gastroenterology and hepatology. | this is a review of some of the most important growing points in the specialties of gastroenterology and hepatology. it does not aim to be completely comprehensive but to pick out major areas of importance to examination candidates and doctors without special experience in the field. topics covered include: upper gastrointestinal haemorrhage; barrett's oesophagus; carcinoma of the oesophagus; achalasia; helicobacter pylori; duodenal ulcer prevention; coeliac disease; dermatitis herpetiformis; cr ... | 2000 | 10824044 |
| [helicobacter pylori and coronary heart diseases--hypotheses and facts]. | in 1994 mendall et al. (9) have suggested that there might be a correlation between helicobacter pylori (hp) infection and coronary heart disease (chd), mediated by a chronic low-grade acute phase reaction with mildly raised serum or plasma concentrations of c-reactive protein and fibrinogen. according to this hypothesis, a gastric hp colonization might be an additional risk factor for chd. in the meantime, 35 studies have examined whether hp seropositivity is associated with chd occurrence. how ... | 2000 | 10820865 |
| morphologic differentiation of hl-60 cells is associated with appearance of rptpbeta and induction of helicobacter pylori vaca sensitivity. | phorbol 12-myristate 13-acetate (pma) induces differentiation of human leukemic hl-60 cells into cells with macrophage-like characteristics and enhances the susceptibility of hl-60 cells to the helicobacter pylori vaca toxin (de bernard, m., moschioni., m., papini, e., telford, j. l., rappuoli, r., and montecucco, c. (1998) febs lett. 436, 218-222). we examined the mechanism by which hl-60 cells acquire sensitivity to vaca, in particular, looking for expression of rptpbeta, a vaca-binding protei ... | 2000 | 10809755 |
| matrix metalloproteinase expression in cultured human gastric wall fibroblasts--interactions with helicobacter pylori isolated from patients with ulcers. | matrix metalloproteinases (mmps), enzymes capable of degrading collagens and other extracellular matrix components, have been implicated in gastric ulcer formation. however, the effect on mmp expression of helicobacter pylori, also implicated in these lesions, has not been studied to our knowledge. | 2000 | 10807424 |
| a new mechanism for anti-inflammatory actions of proton pump inhibitors--inhibitory effects on neutrophil-endothelial cell interactions. | neutrophil-endothelial cell interactions mediated by adhesion molecules may be involved in gastric mucosal inflammation associated with helicobacter pylori or nonsteroidal anti-inflammatory drugs. | 2000 | 10807407 |
| helicobacter pylori. one bacterium and a broad spectrum of human disease! an overview. | since the historical rediscovery of gastric spiral helicobacter pylori in the gastric mucosa of patients with chronic gastritis by warren and marshall in 1983, peptic ulcer disease has been largely viewed as being of infectious aetiology. indeed, there is a strong association between the presence of h. pylori and chronic active gastritis in histology. the bacterium can be isolated in not less than 70% of gastric and in over 90% of duodenal ulcer patients. eradication of the organism has been ass ... | 2000 | 10791696 |
| helicobacter infection in dogs and cats: facts and fiction. | the discovery of the spiral bacterium helicobacter pylori and its causative role in gastric disease in humans has brought a dramatic change to gastroenterology. although spiral bacteria have been known for more than a century to infect the stomachs of dogs and cats, recent research has been conducted mainly in the wake of interest in h. pylori. h. pylori has not been found in dogs and only very rarely in cats and zoonotic risk is minimal. a variety of other helicobacter spp. can infect the stoma ... | 2000 | 10772482 |
| structure of an atypical o-antigen polysaccharide of helicobacter pylori containing a novel monosaccharide 3-c-methyl-d-mannose. | lipopolysaccharides (lps) were isolated by hot phenol-water extraction from danish helicobacter pylori strains d1, d3, and d6, which were nontypeable using a variety of anti-lewis and anti-blood-group monoclonal antibodies. an atypical o-chain polysaccharide (ps) was liberated from the lps of the three strains by acid under mild conditions and found to contain d-rhamnose (d-rha), l-rhamnose (l-rha), and a branched sugar, 3-c-methyl-d-mannose (d-man3cme). the last sugar, which has not hitherto be ... | 2000 | 10769132 |
| role of activated protein c in helicobacter pylori-associated gastritis. | the protein c (pc) pathway has recently been suggested to play a role in the regulation of the inflammatory response. to further extend the anti-inflammatory effect of activated pc (apc) in vivo, particularly its biological relevance to human disease, the activity of apc in the mucosa of patients with helicobacter pylori-associated gastritis and the effect of vacuolating cytotoxin (vaca), cytotoxin-associated antigen (caga), and h. pylori lipopolysaccharide (lps) on pc activation were evaluated. ... | 2000 | 10768983 |
| h pylori colocalises with muc5ac in the human stomach. | the bacterium helicobacter pylori is able to adhere to and to colonise the human gastric epithelium, yet the primary gene product responsible as a receptor for its adherence has not been identified. | 2000 | 10764701 |
| water extract of helicobacter pylori stimulates interleukin-8 secretion by a human gastric epithelial cell line (jr-st) through protein tyrosine phosphorylation. | infection by helicobacter pylori induces cytokine production in gastric mucosal cells. production of interleukin-8 (il-8) is known to be markedly increased and is believed to play an important role in gastric mucosal inflammation. the aim of this study was to elucidate the effects of soluble factors of h. pylori on il-8 production in a gastric epithelial cell line, jr-st. | 2000 | 10764026 |
| apoptotic depletion of infiltrating mucosal lymphocytes associated with fas ligand expression by helicobacter pylori-infected gastric mucosal epithelium: human glandular stomach as a site of immune privilege. | h. pylori infection almost invariably results in chronic gastritis, but only a proportion of patients develops severe destruction of epithelial glandular structure or peptic ulcer. to confirm the recent data obtained in testis and eye, showing that fas ligand is involved in the phenomenon of "immune privilege," expression of fas receptor and its ligand of the stomach was investigated in a panel of gastric biopsies obtained from patients h. pylori-positive (n = 42) and with h. pylori-negative (n ... | 2000 | 10759249 |
| low prevalence of helicobacter pylori in individuals with htlv-i infection. | the prevalence of helicobacter pylori in hiv-positive individuals is significantly lower than in hiv-negative controls. however, its prevalence in individuals infected with human t-cell leukaemia virus type i (htlv-i), another important member of the human retrovirus family, has not been previously investigated. | 1999 | 10755252 |
| helicobacter pylori induces apoptosis in gastric epithelial cells through inducible nitric oxide. | gastric mucosal injury by helicobacter pylori has been suggested to be mediated by various cytokines induced by this organism. nitric oxide (no) is an important effector molecule involved in immune regulation and defence. to clarify the mechanisms by which h. pylori induces gastric mucosal cell injury, we examined whether h. pylori induces gastric epithelial death via no production. | 2000 | 10735541 |
| helicobacter pylori possesses two chey response regulators and a histidine kinase sensor, chea, which are essential for chemotaxis and colonization of the gastric mucosa. | infection of the mucous layer of the human stomach by helicobacter pylori requires the bacterium to be motile and presumably chemotactic. previous studies have shown that fully functional flagella are essential for motility and colonization, but the role of chemotaxis remains unclear. the two-component regulatory system chea/chey has been shown to play a major role in chemotaxis in other enteric bacteria. scrutiny of the 26695 genome sequence suggests that h. pylori has two chey response regulat ... | 2000 | 10722597 |
| innate immunity and the normal microflora. | this paper discusses the following ten subtitles with the contents indicated. 1. to meet a microbe: discusses the four alternatives in host-microbe interactions. 2. receptors and signal transduction giving gene activation: discusses the lipopolysaccharide receptor and the limitations of cell cultures versus use of live animals. 3. effector molecules--antimicrobial peptides with and without cysteines. a data base exists with over 500 sequences. this paper gives a general overview of five classes ... | 2000 | 10719663 |
| unique mechanism of helicobacter pylori for colonizing the gastric mucus. | helicobacter pylori is a human gastric pathogen causing chronic infection. urease and motility using flagella are essential factors for its colonization. urease of h. pylori exists both on the surface and in the cytoplasm, and is involved in neutralizing gastric acid and in chemotactic motility. h. pylori senses the concentration gradients of urea in the gastric mucus layer, then moves toward the epithelial surface by chemotactic movement. the energy source for the flagella movement is the proto ... | 2000 | 10717541 |
| expression of secretory group iia phospholipase a(2) in relation to the presence of microbial agents, macrophage infiltrates, and transcripts of proinflammatory cytokines in human aortic tissues. | recent seroepidemiological and immunohistochemical studies have demonstrated an association between microbial infections and atherosclerosis. however, the mechanisms underlying this association are widely unknown. in the present study, arterial specimens obtained at autopsy after sudden death were analyzed concerning (1) the presence of chlamydia pneumoniae, cytomegalovirus, herpes simplex virus, and helicobacter pylori; (2) the expression of secretory group iia phospholipase a(2) (spla(2)-iia) ... | 2000 | 10712401 |
| intestinal and pancreatic metaplasia at the esophagogastric junction in patients without barrett's esophagus. | a distinctive type of columnar epithelium with intestinal metaplasia is considered diagnostic for barrett's esophagus. the neoplastic potential of pancreatic metaplasia at the esophagogastric junction is unknown. the aims of the present study were: 1) to characterize both forms of metaplasia at the esophagogastric junction, and to estimate their prevalence; 2) to investigate c-erbb-2 expression and k-ras mutations in pancreatic metaplasia; and 3) to study the relationship between metaplasia, inf ... | 2000 | 10710048 |
| helicobacter pylori-antigen-binding fragments expressed on the filamentous m13 phage prevent bacterial growth. | colonization of the human stomach by helicobacter pylori is associated with the development of gastritis, duodenal ulcer, mucosa-associated lymphoid tissue (malt) lymphoma, and gastric cancer. h. pylori-antigen-binding single-chain variable fragments (scfv) were derived from murine hybridomas producing monoclonal antibodies and expressed as a g3p-fusion protein on a filamentous m13 phage. the recombinant scfv-phage reacted specifically with a 30-kda monomeric protein of a h. pylori surface antig ... | 2000 | 10699497 |
| identification of helicobacter pylori and other helicobacter species by pcr, hybridization, and partial dna sequencing in human liver samples from patients with primary sclerosing cholangitis or primary biliary cirrhosis. | helicobacter pylori was identified in human liver tissue by pcr, hybridization, and partial dna sequencing. liver biopsies were obtained from patients with primary sclerosing cholangitis (n = 12), primary biliary cirrhosis (n = 12), and noncholestatic liver cirrhosis (n = 13) and (as controls) normal livers (n = 10). pcr analyses were carried out using primers for the helicobacter genus, helicobacter pylori (the gene encoding a species-specific 26-kda protein and the 16s rrna), helicobacter bili ... | 2000 | 10698999 |
| the carcinogenic effect of h. pylori on the gastric epithelial cell. | the recent demonstration in animal models that h. pylori alone may be capable of inducing intestinal-type gastric cancer, and that h. felis can accelerate gastrin-induced gastric neoplasia has stimulated research on examining the mechanisms of h. pylori-associated carcinogenesis in humans. several mechanisms are currently under investigation, including the dysregulation of the gastric epithelial cell cycle, the formation of dna adducts, the generation of free radicals, alterations in growth fact ... | 1999 | 10695564 |
| purification of surface-associated urease from helicobacter pylori. | helicobacter pylori colonizes the human gastric mucosa and produces large amounts of urease. the enzyme was extracted from the bacteria by distilled water and purified by gel-permeation (sephacryl s-300), anion-exchange chromatography (mono q) and a second gel-permeation (superdex 200). urease enzyme activity was detected with a spectrophotometic assay based on phenol red. the optimal ph for anion-exchange was 6.9. the recovery of urease was 55-75%, purity 93-98% and the overall protein recovery ... | 2000 | 10681057 |
| 9th seah cheng siang memorial lecture: gastric cancer--where are we now? | gastric cancer, the second most common cancer in the world, kills about one million people a year, almost half of whom are chinese. chinese, japanese and koreans as well as east europeans top the list with over 40 per 100,000 population per year, with a wide margin over americans, indians and zimbabweans in whom the rates are below 1 per 100,000. the excellent prognosis of early gastric cancer is well established, and survival of cancer involving beyond the submucosa remains poor and there is li ... | 1999 | 10672411 |
| in search of immunogenic helicobacter pylori proteins by screening of expression library. | prevention of helicobacter pylori infection may help to control related gastritis, peptic ulcer and cancer. of the possible preventive measures, immunization was successfully employed in various animal studies. however, no immunization protocol has been accepted for humans. a better characterization of the immune response against the pathogen may be required before a human vaccine is developed. | 2000 | 10671770 |
| cell damage and proliferation in human gastric mucosa infected by helicobacter pylori--a comparison before and after h pylori eradication in non-atrophic gastritis. | helicobacter pylori (hp) is believed to be involved in the transition from normal gastric mucosa to atrophic gastritis and intestinal metaplasia. infection with the organism is one of the risk factors for development of intestinal-type gastric adenocarcinoma, possibly through altered cell turnover. medical eradication of hp is widely performed for the treatment of peptic ulcers and other upper gastrointestinal disorders. eradication of hp may affect altered cell turnover of the gastric mucosa ca ... | 1999 | 10667417 |
| treatment of h. pylori infected mice with antioxidant astaxanthin reduces gastric inflammation, bacterial load and modulates cytokine release by splenocytes. | helicobacter pylori is a gram-negative bacterium affecting about half of the world population, causing chronic gastritis type b dominated by activated phagocytes. in some patients the disease evolves into gastric ulcer, duodenal ulcer, gastric cancer or malt lymphoma. the pathogenesis is in part caused by the immunological response. in mouse models and in human disease, the mucosal immune response is characterized by activated phagocytes. mucosal t-lymphocytes are producing ifn-gamma thus increa ... | 1999 | 10656672 |
| modulation of helicobacter pylori induced interleukin-8 synthesis in gastric epithelial cells mediated by cag pai encoded vird4 homologue. | strains of helicobacter pylori carrying the virulence associated cag pathogenicity island (pai) induce gastric epithelial synthesis of the chemokine interleukin-8 (il-8), a neutrophil chemoattractant, and thereby a strong inflammatory response during chronic infection of the human gastric mucosa. previous mutational analyses have shown that many genes in the cag pai are needed to elicit il-8 synthesis in gastric epithelial cells, and also that some genes are not involved. | 1999 | 10655985 |
| helicobacter pylori activates the histidine decarboxylase promoter through a mitogen-activated protein kinase pathway independent of pathogenicity island-encoded virulence factors. | helicobacter pylori infection of the gastric mucosa is accompanied by an activated histamine metabolism. histamine plays a central role in the regulation of gastric acid secretion and is involved in the pathogenesis of gastroduodenal ulcerations. histidine decarboxylase (hdc) is the rate-limiting enzyme for histamine production, and its activity is regulated through transcriptional mechanisms. the present study investigated the effect of h. pylori infection on the transcriptional activity of the ... | 2000 | 10652359 |
| therapeutic immunization against helicobacter pylori infection in the absence of antibodies. | helicobacter pylori is an important human pathogen. prophylactic immunization with bacterial antigen plus an adjuvant protects mice against challenge with live h. pylori. surprisingly, it was found that immunizations of mice already infected with helicobacter also influenced bacterial colonization. this concept of therapeutic immunization is a novel phenomenon. because h. pylori lives in the lumen of the stomach, it was initially hypothesized that the protective mechanism would involve induction ... | 2000 | 10651926 |
| h. pylori in the pathogenesis of duodenal ulcer: interaction between duodenal acid load, bile, and h. pylori. | helicobacter pylori (h. pylori) growth is inhibited by bile yet it can grow in the duodenal bulb and cause ulcer disease. the aim of this study was to test the effect of bile on h. pylori viability and growth and to determine whether acidification of bile reduces its inhibitory activity. | 2000 | 10638564 |
| inhibition by 16,16-dimethyl prostaglandin e2 of tumor necrosis factor-alpha and interleukin-1beta production and messenger rna expression in human monocytes stimulated by helicobacter pylori. | we investigated the effects of 16,16-dimethyl prostaglandin e2 on the production of tumor necrosis factor-alpha and interleukin-1beta in human monocytes stimulated with helicobacter pylori. monocytes isolated from human peripheral blood were incubated for 24 hr with the extract of h. pylori diluted 1:100 to 1:100,000 by volume, a combination of the extract and 16,16-dimethyl prostaglandin e2, or a vehicle alone. the extract stimulated the production of tumor necrosis factor-alpha and interleukin ... | 1999 | 10630489 |
| potential relevance of agmatine as a virulence factor of helicobacter pylori. | the polyamine agmatine is able to increase gastric acid secretion. therefore, we investigated whether helicobacter pylori is able to form and release agmatine in vitro and in the human stomach in vivo, and if so, whether a relationship exists among agmatine concentration in gastric juice, h. pylori infection, and gastroduodenal lesions. agmatine was determined by means of hplc. in the supernatant of h. pylori cultures, agmatine concentrations up to 1500 ng/ml (approximately 12 microm) were deter ... | 1999 | 10630488 |
| chemotaxis and motility of helicobacter pylori in a viscous environment. | the chemotactic activity of helicobacter pylori is important for its colonization. h. pylori exhibited chemotactic responses to urea and potassium bicarbonate, which can be supplied from human gastric epithelium. the chemotactic activities of h. pylori in a fluid environment were higher on the urease-positive strain than on the isogenic urease-negative strain. in a viscous solution containing 3% polyvinylpyrrolidone, the urease-positive strain showed stimulated chemotactic activity, whereas the ... | 1999 | 10616760 |