Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0043167 (pertussis)
 19,595 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Most strains of Helicobacter pylori from patients with peptic ulcer disease or intestinal-type gastric cancer carry cagA, a gene that encodes an immunodominant protein of unknown function, whereas many of the strains from asymptomatically infected persons lack this gene. Recent studies showed that the cagA gene lies near the right end of a approximately 37kb DNA segment (a pathogenicity island, or PAI) that is unique to cagA+ strains and that the cag PAI was split in half by a transposable element insertion in the reference strain NCTC11638. In complementary experiments reported here, we also found the same cag PAI, and sequenced a 39 kb cosmid clone containing the left 'cagII' half of this PAI. Encoded in cagII were four proteins each with homology to four components of multiprotein complexes of Bordetella pertussis ('Ptl'), Agrobacterium tumefaciens ('Vir'), and conjugative plasmids ('Tra') that help deliver pertussis toxin and T (tumour inducing) and plasmid DNA, respectively, to target eukaryotic or prokaryotic cells, and also homologues of eukaryotic proteins that are involved in cytoskeletal structure. To the left of cagII in this cosmid were genes for homologues of HsIU (heat-shock protein) and Era (essential GTPase); to the right of cagII were homologues of genes for a type I restriction endonuclease and ion transport functions. Deletion of the cag PAI had no effect on synthesis of the vacuolating cytotoxin, but this deletion and several cag insertion mutations blocked induction of synthesis of proinflammatory cytokine IL-8 in gastric epithelial cells. Comparisons among H. pylori strains indicated that cag PAI gene content and arrangement are rather well conserved. We also identified two genome rearrangements with end-points in the cag PAI. One, in reference strain NCTC11638, involved IS605, a recently described transposable element (as also found by others). Another rearrangement, in 3 of 10 strains tested (including type strain NCTC11637), separated the normally adjacent cagA and picA genes and did not involve IS605. Our results are discussed in terms of how cag-encoded proteins might help trigger the damaging inflammatory responses in the gastric epithelium and possible contributions of DNA rearrangements to genome evolution.
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PMID:Analyses of the cag pathogenicity island of Helicobacter pylori. 959 95

In the first half of the 20th century, improved living conditions, preventive measures, vaccines and antibiotics led to a marked reduction in morbidity and mortality from infectious diseases. It was predicted that the conquest of all infectious diseases was imminent. However, 50 years later, in 1999, they were still the major cause of disease worldwide, and caused nearly one third of all deaths (a total of 55.9 million). The eradication of smallpox in the 1970s and the approaching eradication of poliomyelitis represent major achievements. The prevalence of measles, pertussis and tetanus neonatorum is also markedly reduced, but still 1.5 million children in developing countries die each year because of lack of vaccines. Malaria and tuberculosis are re-emerging. Tuberculosis and HIV/AIDS are the diseases with known aetiology that cause most deaths, altogether 5 million each year. Respiratory and gastrointestinal infections cause 6.5 million deaths annually. Infections in the immunocompromised host have become a "trade mark" of today's advanced medicine. Almost every year, new diseases related to new micro-organisms are described; over the last 30 years, approximately 40 new diseases/micro-organisms have been diagnosed. Among the best known are HIV/AIDS, peptic ulcer caused by Helicobacter pylori, Legionnaires' disease, borreliosis (Lyme disease), hepatitis C, gastroenteritis caused by rotavirus, and Ebola haemorrhagic fever. Antimicrobial resistance development of micro-organisms has become one of the major health problems worldwide; a number of preventive measures are being introduced.
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PMID:[Microorganisms strike back--infectious diseases during the last 50 years]. 1180 14

Helicobacter pylori (H. pylori) is an important risk factor for chronic gastritis, peptic ulcer, and gastric cancer. Proteinase-activated receptor 2 (PAR2), subgroup of G-protein coupled receptor family, is highly expressed in gastric cancer, and chronic expression of cyclooxygenase-2 (COX-2) plays an important role in H. pylori-associated gastric carcinogenesis and inflammation. We previously demonstrated that H. pylori induced the expression of PAR2 and COX-2 in gastric epithelial cells. Present study aims to investigate whether COX-2 expression induced by H. pylori in Korean isolates is mediated by PAR2 via activation of G(i) protein and Src kinase in gastric epithelial AGS cells. Results showed that H. pylori-induced COX-2 expression was inhibited in the cells transfected with antisense oligonucleotide for PAR2 or treated with Gi protein blocker pertussis toxin, Src kinase inhibitor herbimycin A and soybean trypsin inbitor, indicating that COX-2 expression is mediated by PAR2 through activation of Gi protein and Src kinase in gastric epithelial cells infected with H. pylori in Korean isolates. Thus, targeting the activation of PAR2 may be beneficial for prevention or treatment of gastric inflammation and carcinogenesis associated with H. pylori infection.
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PMID:Effect of pertussis toxin and herbimycin A on proteinase-activated receptor 2-mediated cyclooxygenase 2 expression in Helicobacter pylori-infected gastric epithelial AGS cells. 2148 97