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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. Prostaglandin A-, prostaglandin E- and prostaglandin F-like substances were determined radioimmunologically in antral biopsy material obtained by endoscopy. 2. In patients with gastritis, the concentrations of prostaglandin (E+A)-like substances were six times as high and of prostaglandin F-like substances twice as high as in normal subjects. In chronic atrophic gastritis, the concentrations of prostaglandin (E+A)-like material was four times as high as in normal subjects whereas prostaglandin-F like material remained unchanged. In acute gastric ulcer, prostaglandin (E+A)-like material reached concentrations four times times higher than in normal subjects, accompanied by a fivefold increase of prostglandin F-like substances. After healing of the gastric ulcer, prostaglandins returned to normal values. 3. There was no correlation between gastrin and prostaglandins in all biopsy specimens.
Clin Sci Mol Med 1977 Mar
PMID:Concentrations of prostaglandin A-, E- and F-like substances in gastric mucosa of normal subjects and of patients with various gastric diseases. 84 56

Diverse strains of Helicobacter pylori were examined in order to initiate a molecular epidemiological typing scheme for this agent of human gastritis. Twelve differently-sized plasmids from 1.8 to 63 kbp were identified in those strains harbouring extrachromosomal DNA. Recombinant DNA probes were cloned randomly from the chromosome of the (plasmid-free) type strain (NCTC 11637), and used to probe genomic Southern blots for restriction site variation in and around homologous loci. Genus-specific probe DNAs were obtained which grouped strains on the bases of DNA base substitution or rearrangements. On the basis of the four probes examined, all strains exhibited intraspecific chromosomal divergence, indicating that H. pylori is highly diverse genetically, but nonetheless susceptible to chromosome and plasmid molecular typing.
Mol Cell Probes 1992 Aug
PMID:Molecular typing of Helicobacter pylori by chromosomal and plasmid DNA organization. 135 27

Helicobacter pylori has been implicated in the genesis of human gastritis, dyspepsia, and peptic ulcers. However, its influence in the quality of experimental gastric ulcer healing has not been previously investigated. Standardized gastric fundic ulcers were produced in 50 male Sprague-Dawley rats (150-200 g) by a 4 mm in diameter focal, serosal application of 100% acetic acid. Thirty rats were administered 2 ml H. pylori suspension (urease producing, ATCC 43504) in normal saline (10(8) CFU/ml) 2x/day for 7 days. Twenty rats (controls) received 2 ml normal saline 2x/day for 7 days. Gastric ulcer surface area was measured under a dissecting microscope and mucosal specimens were obtained for qualitative and quantitative histology. No gross or microscopic duodenal abnormalities were identified at sacrifice. Ninety percent of control rats showed grossly and microscopically entirely healed ulcers. The remaining 10% showed partially reepithelialized ulcers (area, 0.78 to 1.77 mm2; mean, 1.27 +/- 0.7 mm2). The grossly "healed" mucosa demonstrated marked dilatation of gastric glands lined with mature surface epithelial cells. Parietal cells were scanty (5-10% of all cells). One hundred percent of the H. pylori-exposed rats showed persistence of chronic active ulcers (area, 1.76 to 19.63 mm2; mean, 8.95 +/- 6.15 mm2). The ulcer beds were infiltrated by acute and chronic inflammatory cells, abundant fibroblasts, and capillary networks. The raised ulcer borders were characterized by dilated glands lined by mature surface epithelial cells. Various special stains demonstrated the presence of H. pylori in the surface mucus and within the crypts.(ABSTRACT TRUNCATED AT 250 WORDS)
Exp Mol Pathol 1991 Dec
PMID:Helicobacter pylori affects the quality of experimental gastric ulcer healing in a new animal model. 174 15

Gastric mucosa obtained from the body and pyloric portions of the human stomach were observed by light and transmission electron microscopy. Ciliated cells were found in two of 18 subjects examined, one patient with gastric ulcer and the other one with gastric adenocarcinoma. The ciliated cells were found in epithelia at sites away from the main lesions. The tissues containing ciliated cells showed intestinal metaplasia combined with mild chronic gastritis in both cases. The epithelial layer facing the gastric lumen was composed of columnar cells with numerous uniform microvilli and goblet cells. This epithelium extended to the superficial parts of the tubules surrounded by the lamina propria. The deeper portions of the tubules were composed of mucous secretory, endocrine, and rarely ciliated cells. These ciliated cells were provided with numerous cilia the numbers of which varied considerably from cell to cell. This was in contrast to the primary cilium which is usually single. The central part of the apical cell membrane was sometimes concave in the area from where cilia tended to arise. It was also observed that numerous basal bodies as well as mucus-like granules were contained in the same cell. The axonemal pattern was different from that of ordinary cilia and showed 9 + 0 and 8 + 1 patterns. In longitudinal sections it was found that one peripheral doublet was displaced to the center of the axoneme as it left the basal body.
Virchows Arch B Cell Pathol Incl Mol Pathol 1986
PMID:The fine structure of atypical ciliated cells in the human gastric epithelium. 287 43

Urease is a virulence determinant, a taxonomic and diagnostic marker, and immunogen for Helicobacter pylori, an aetiologic agent of gastritis and peptic ulceration. This enzyme requires Ni2+ ions in the active site for successful hydrolysis of urea. When expressed in Escherichia coli, recombinant urease is only weakly active unless urease structural subunits are overexpressed, exogenous NiCl2 is added, and the host strain is grown in medium that does not chelate free Ni2+. As wild-type H. pylori does not require such conditions for very high levels of urease expression, we reasoned that additional genes were required to accumulate the metal ion. To isolate such genes, E. coli SE5000 (pHP808), which carries the H. pylori urease gene cluster, was complemented with a lambda ZAP-derived plasmid library of the H. pylori chromosome. One of 1000 ampicillin-resistant clones, plated onto urea segregation agar, produced detectable urease. Urease activity of this co-transformant, grown in Luria broth containing 1 microM NiCl2, was 36 mumol NH3 min-1 mg-1 protein. Urease-enhancing activity, which is not directly linked to the urease gene cluster, was localized by subcloning and nucleotide sequencing. The largest open reading frame, designated nixA, predicted a polypeptide of 34,317 Da that displayed characteristics of an integral membrane protein. In vitro transcription-translation of nixA sequences yielded a polypeptide estimated to be 32 kDa in size. An in-frame Bal31 deletion within nixA abolished urease-enhancing activity. At 50 nM NiCl2, E. coli containing the nixA clone transported 1250 +/- 460 pmol Ni2+ min-1 10(-8) cells, whereas the vector control transported only 140 +/- 85 pmol Ni2+ min-1 10(8) cells, i.e. significantly less (P = 0.01). We conclude that NixA confers upon E. coli a high-affinity nickel-transport system (KT = 11.3 +/- 2.4 nM; Vmax = 1750 +/- 220 pmol Ni2+ min-1 10(-8) cells) and is necessary for expression of catalytically active urease, regardless of growth conditions.
Mol Microbiol 1995 Apr
PMID:Helicobacter pylori nickel-transport gene nixA: synthesis of catalytically active urease in Escherichia coli independent of growth conditions. 765 Nov 42

The human gastric bacterial pathogen Helicobacter pylori has been implicated in type B gastritis, peptic ulceration and gastric adenocarcinoma. Here we report on the cloning and genetic characterization of an H. pylori gene named vacA, which encodes the vacuolating cytotoxin VacA, a novel type of antigenic bacterial toxin that induces the formation of intracellular vacuoles in epithelial cells. The vacuolating cytotoxin activity is expressed by a subset of clinical isolates (Vac+), all of which produce the 87 kDa cytotoxin antigen, but strains which produce neither the activity nor the cytotoxin protein (Vac-) also carry the gene. Isogenic H. pylori mutants in vacA generated by transposon shuttle mutagenesis produce neither the VacA antigen nor a vacuolating activity in a cell culture model. The vacA gene itself encodes a precursor protein of 139.6 kDa consisting of a 33-amino acid signal sequence, the 87 kDa cytotoxin and a 50 kDa C-terminal domain with features typical of a bacterial outer membrane protein. The VacA precursor shows no significant primary sequence homology with any previously reported protein, but its structural organization closely resembles the IgA protease-type of exoprotein produced by pathogenic Neisseriae and Haemophilus species. Our current data support a model for secretion of the cytotoxin through the two bacterial membranes which involves the 50 kDa domain for outer membrane translocation with subsequent proteolytic cleavage and release of the mature 87 kDa cytotoxin into the extracellular environment.
Mol Microbiol 1994 Apr
PMID:Genetic analysis of the Helicobacter pylori vacuolating cytotoxin: structural similarities with the IgA protease type of exported protein. 805 55

Helicobacter pylori is a human pathogen that has been associated with gastritis, peptic ulcer and gastric carcinoma. The role of the direct action of H. pylori virulence factors and of the induction of autoreactive immunity in the development of chronic gastritis has not been clarified yet. Here we report the cloning and molecular characterization of a gene of H. pylori coding for a protein of 58 kDa, recognized by sera of patients affected by H. pylori-induced gastroduodenal diseases. This antigen is present in all the H. pylori strains tested and it belongs to the Hsp60 family of heat-shock proteins, with high homology with other bacterial and eukaryotic proteins of the same family. This class of homologous proteins has been implicated in the induction of autoimmune disorders in different systems. The presence in infected patients of anti-H. pylori Hsp60 antibodies, potentially cross-reactivity between human Hsp60 and a rabbit antiserum against H. pylori Hsp60 suggest that a role of this protein in gastroduodenal diseases is possible.
Mol Microbiol 1993 Aug
PMID:The Hsp60 protein of Helicobacter pylori: structure and immune response in patients with gastroduodenal diseases. 810 64

A new system for the detection of Helicobacter pylori DNA, based on the method of directed amplification, has been developed. Primers for specific detection of H. pylori were selected from a nucleotide sequence of 16 S-p RNA. The sequences of the primers had a few nucleotide substitutions as compared with the sequences of closely related microorganisms. An essential condition for the attainment of reaction specificity was the rise of annealing step temperature to 66 degrees C. Sensitivity of the system was in the range of 3 to 30 fg of DNA, or 20 to 100 bacterial cells. Using the proposed system for the detection of H. pylori DNA clinical specimens (stomach biopsy sample, gastric juice and wash-offs of oral cavity), obtained from 49 patients with antral gastritis, were analyzed. The method of H. pylori detection in clinical specimens using polymerase chain reaction (PCR) turned out to be more sensitive compared with microbiological tests. By application of PCR H. pylori DNA was detected in subgingival pockets.
Mol Gen Mikrobiol Virusol
PMID:[Use of the polymerase chain reaction to identify Helicobacter pylori in clinical material]. 813 43

Helicobacter pylori is a Gram-negative bacterium that infects the human gastric mucosa, causes gastritis and contributes to the development of peptic ulcers and gastric cancer. To facilitate molecular genetic analysis of this pathogen, we constructed a approximately 20-fold redundant cosmid library and physical/genetic map of strain NCTC11638. Genomic DNA fragments were cloned into the cosmid vector Lorist6, and clones were ordered by hybridization with several types of probes: (i) ends of cloned DNAs; (ii) chromosomal Notl digest fragments; (iii) cosmids containing Notl sites; and (iv) specific genes. Seven hundred and fifty-one cosmids were mapped to one of three contigs covering > 90% of the chromosome, and are represented by a 68-cosmid miniset. The order of cosmids was confirmed and extents of overlap among them were estimated by restriction analysis. All currently known H. pylori genes were mapped, including those for a cytotoxin (vacA), cytotoxin-associated protein (cagA), urease and regulatory functions (ureAb, ureD and ureH), catalase (katA), major and minor flagellins (flaA and flaB), heat-shock (stress) and chaperone proteins (dnaK, htA, hspB (groEL)), prokaryotic ferritin (pfr), an adhesin subunit (hpaA), a surface protein (26 kDa), and 16S and 23S ribosomal RNAs (two genes each). The orientations of eight genes or clusters were determined, and two repetitive sequences were also found. The gene order and rRNA gene copy number determined here differed from that reported for an unrelated strain, which suggests considerable flexibility in H. pylori genome organization.
Mol Microbiol 1994 Feb
PMID:Ordered cosmid library and high-resolution physical-genetic map of Helicobacter pylori strain NCTC11638. 815 75

The spiral microaerophilic bacterium Helicobacter mustelae is linked to gastritis and gastric ulcers in ferrets. Electron microscopy of H. mustelae showed the presence of a laterally extensive array of 8.5-nm-diameter rings on the cell surface, which was shown to be composed of a 150kDa protein. This protein was purified, and the sequence of 10 amino-terminal residues was determined. Polyclonal antibody against the purified 150 kDa protein labelled the ring structures on the homologous strain by means of immunogold. Cross-reactive proteins were identified in three H. mustelae strains, but not in Helicobacter pylori or Helicobacter felis. The hsr gene encoding this protein was cloned, and the protein expressed in Escherichia coli independently of vector promoters. The 1519-codon nucleotide sequence of the gene was determined, and comparison with the chemically derived protein sequence indicated a 47-residue leader peptide, and a mature protein with a molecular weight of 152,300. Thus the cell surface of H. mustelae differs markedly from other members of the genus Helicobacter in being covered by an array of 8.5 nm rings composed of a 150kDa protein.
Mol Microbiol 1994 Jan
PMID:Identification and molecular characterization of a major ring-forming surface protein from the gastric pathogen Helicobacter mustelae. 817 Mar 97


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