Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01350 (gastrin)
 9,683 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Incorporation of di-fatty acylglycerol moieties at the N-terminus of human little-gastrin-(2-17) leads to self-aggregation of the resulting lipo-gastrins into stable, most probably fluid vesicles. Net intervesicular transfer of the lipo-gastrins to phosphatidyl-choline model bilayers occurs at high rates whereby the chain length of the gastrin lipid moiety was found to affect the transfer rate more decisively than the nature of the acceptor vesicle. Similarly, the bioactivity of the lipo-gastrins is again affected by the nature of the lipid moiety suggesting differentiated interdigitation with the natural bilayer components and thus, different two-dimensional migration rates to the target receptors. Embedment of the lipo-gastrins in phosphatidylcholine bilayers at high lipid/gastrin ratios as mimicry of the cell membrane bound state does not result in onset of ordered structure, but leads to full exposure of the gastrin in essentially randomly coiled form at the water/lipid interface. This may result from the artificial N-terminal anchorage of the gastrin molecules to the bilayers, but also from the relatively tight packing of the phosphatidylcholine vesicles. Nevertheless, this observation might suggest that in the present case membrane-induced conformation and orientation may not represent a pre-requisite for the hormone receptor binding process. However, the results of this study clearly confirm even for the non-amphiphilic hormone gastrin a membrane-bound pathway for receptor recognition and occupancy.
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PMID:Peptide hormone-membrane interactions. Intervesicular transfer of lipophilic gastrin derivatives to artificial membranes and their bioactivities. 843 55

Chronic atrophic corpus gastritis, termed as autoimmune corpus gastritis or type A gastritis, and primary biliary cirrhosis (PBC) are characterized by a common immunological process against the exocrine glandular structures of both the stomach and bile duct. However, there has been controversy over whether atrophic corpus gastritis is associated with PBC. Recently, it has been suggested that Helicobacter pylori plays an important role in the early stage of atrophic corpus gastritis due to the induction of autoantibodies that are reactive with a protein in the gastric parietal cells. One hypothesis is that molecular mimicry, possibly resulting from H. pylori infection, might be responsible for initiating an autoimmune response in a predisposed host due to cross-reactivity among gastric mucosal, bile ductular, and bacterial antigens. The aim of this study is to assess whether atrophic changes of the gastric corpus could affect patients with PBC, and to determine the correlation with H. pylori infection. Sixteen patients with PBC were enrolled in this study. All patients were examined by serological studies of anti-pyruvate dehydrogenase (PDH) antibody, anti-H. pylori antibody, gastrin and vitamin B12. Gastroscopy was performed on all patients in order to verify the histological findings and to microscopically identify H. pylori. Atrophic corpus gastritis was found in 2 of 16 patients with PBC (12.5%), one of whom was confirmed to have pernicious anemia, a developed stage of atrophic corpus gastritis. H. pylori infection in the gastric corpus and the anti-H. pylori antibody were found in 7 (43.8%) and 11 (68.8%) of 16 patients, respectively. Anti-H. pylori antibody was confirmed to be positive in both of the patients with atrophic corpus gastritis, although H. pylori was absent in the gastric biopsy specimen. There was a positive correlation between anti-PDH antibodies and anti-H. pylori antibodies in sera from patients with PBC. Atrophic corpus gastritis is not frequently involved in PBC. However, H. pylori is a possible pathogenic factor in atrophic corpus gastritis in PBC patients because of the presence of anti-H. pylori antibody. A positive correlation between the titer of anti-PDH antibodies and the titer of anti-H. pylori antibodies was confirmed. Consequently, H. pylori infection could induce autoimmune responses in the development of both PBC and atrophic corpus gastritis. H. pylori infection associated with PBC requires further study.
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PMID:Atrophic corpus gastritis and Helicobacter pylori infection in primary biliary cirrhosis. 1183 19

The great success of therapeutic monoclonal antibodies has fueled research toward mimicry of their binding sites and the development of new strategies for peptide-based mimetics production. Here, we describe a new combinatorial approach for the production of peptidomimetics using the complementarity-determining regions (CDRs) from gastrin17 (pyroEGPWLEEEEEAYGWMDF-NH(2)) antibodies as starting material for cyclic peptide synthesis in a microarray format. Gastrin17 is a trophic factor in gastrointestinal tumors, including pancreatic cancer, which makes it an interesting target for development of therapeutic antibodies. Screening of microarrays containing bicyclic peptidomimetics identified a high number of gastrin binders. A strong correlation was observed between gastrin binding and overall charge of the peptidomimetic. Most of the best gastrin binders proceeded from CDRs containing charged residues. In contrast, CDRs from high affinity antibodies containing mostly neutral residues failed to yield good binders. Our experiments revealed essential differences in the mode of antigen binding between CDR-derived peptidomimetics (K(d) values in micromolar range) and the parental monoclonal antibodies (K(d) values in nanomolar range). However, chemically derived peptidomimetics from gastrin binders were very effective in gastrin neutralization studies using cell-based assays, yielding a neutralizing activity in pancreatic tumoral cell lines comparable with that of gastrin-specific monoclonal antibodies. These data support the use of combinatorial CDR-peptide microarrays as a tool for the development of a new generation of chemically synthesized cyclic peptidomimetics with functional activity.
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PMID:A combinatorial approach for the design of complementarity-determining region-derived peptidomimetics with in vitro anti-tumoral activity. 1980 84

Despite elegant regulatory mechanisms, iron deficiency anemia (IDA) remains one of the most common nutritional deficiencies of mankind. Iron deficiency is the result of an interplay between increased host requirements, limited external supply, and increased blood loss. When related to increased physiologic needs associated with normal development, iron deficiency is designated physiologic or nutritional. By contrast, pathological iron deficiency, with the exception of gross menorrhagia, is most often the result of gastrointestinal disease associated with abnormal blood loss or malabsorption. If gastroenterologic evaluation fails to disclose a likely cause of IDA, or in patients refractory to oral iron treatment, screening for celiac disease (anti-tissue transglutaminase antibodies), autoimmune gastritis (gastrin, anti-parietal or anti-intrinsic factor antibodies), and Helicobacter pylori (IgG antibodies and urease breath test) is recommended. Recent studies indicate that 20-27% of patients with unexplained IDA have autoimmune gastritis, about 50% have evidence of active H. pylori infection, and 4-6% have celiac disease. The implications for abnormal iron absorption of celiac disease or autoimmune gastritis are obvious. In patients with unexplained IDA and H. pylori infection, cure of refractory IDA by H. pylori eradication offers strong evidence for a cause-and-effect relation between H. pylori infection and unexplained IDA. Stratification by age cohorts in autoimmune gastritis implies a disease presenting as IDA many years before the establishment of clinical cobalamin deficiency. It is likely caused by an autoimmune process triggered by antigenic mimicry between H. pylori epitopes and major autoantigens of the gastric mucosa. Recognition of the respective roles of H. pylori and autoimmune gastritis in the pathogenesis of iron deficiency may have a strong impact on the diagnostic workup and management of unexplained, or refractory IDA.
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PMID:Iron deficiency, Helicobacter infection and gastritis. 1990 46