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)

Serum concentrations of group I pepsinogens (pepsinogen-I) and gastrin were determined in patients with dementia disorders in order to assess the relationship, if any, between these indices of gastric mucosal function and serum cobalamin (vitamin B12) levels. A significant positive correlation between pepsinogen-I and B12 and, as expected, an inverse relationship between gastrin and pepsinogen-I concentrations was found, indicating that vitamin B12 deficiency was mainly determined by gastric mucosal atrophy (atrophic gastritis) in this West-Swedish sample of patients with dementia disorders. Patients with low B12 but normal gastrin and pepsinogen-I concentrations should, therefore, be further evaluated for possible nutritional deficiency, as well as nongastric causes of poor B12 assimilation from the diet.
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PMID:Dementia patients with low serum cobalamin concentration: relationship to atrophic gastritis. 162 75

Intrinsic factor is produced by the gastric parietal cell. Its secretion is stimulated via all pathways known to stimulate gastric acid secretion: histamine, gastrin, and acetylcholine. There is, however, a different mode of secretion for both substances: atropine, vagotomy, and H2 receptor antagonists inhibit both intrinsic factor and acid secretion, but secretin and the hydrogen-potassium ATPase antagonist omeprazole have no effect on intrinsic factor while substantially reducing acid secretion. Cobalamin in food is bound to animal protein. Cobalamin deficiency due to inadequate dietary intake is rarely seen in extreme vegetarians (vegans). In the stomach cobalamin is liberated from its protein binding by peptic digestion and bound to R-proteins. Hypochlorhydria or achlorhydria, whether medically induced or not, may impair cobalamin uptake. The cobalamin-R-protein complex is split by pancreatic enzymes in the duodenum, where cobalamin is bound to intrinsic factor. Pancreatic insufficiency may lead to cobalamin deficiency. Lack of intrinsic factor is the commonest cause of cobalamin deficiency; very rarely, aberrant forms of intrinsic factor are produced, but the clinical syndrome is similar. Gram-negative anaerobe bacteria bind the cobalamin-intrinsic factor complex, and bacterial overgrowth of the small intestine diminishes cobalamin resorption. Parasitic infections with fish tape-worm and Giardia lamblia are also associated with cobalamin malabsorption. The cobalamin-intrinsic factor complex binds to the ileal receptors in the terminal ileum. Cobalamin absorption may be impaired after resection or by diseases affecting more than 50 cm of the terminal ileum, such as Crohn's disease, coeliac disease, tuberculosis, lymphoma or radiation. There is clearly a wide diversity in the aetiology of cobalamin deficiency, which requires a versatile diagnostic approach.
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PMID:Intrinsic factor secretion and cobalamin absorption. Physiology and pathophysiology in the gastrointestinal tract. 177 33

The ratio of pepsinogen I to pepsinogen II in the circulation decreases progressively with increasing severity of atrophic gastritis of the fundic gland mucosa. Fasting blood was obtained from 359 free-living and institutionalized elderly people (age range, 60 to 99 years). A pepsinogen I/pepsinogen II ratio less than 2.9, indicating atrophic gastritis, was found in 113 (31.5%) subjects. The prevalence of atrophic gastritis increased significantly with advancing age (P less than .05). Within the atrophic gastritis group, 84 had a pepsinogen I level greater than or equal to 20 micrograms/L, indicating mild to moderate atrophic gastritis, and 29 had a pepsinogen I level less than 20 micrograms/L, indicating severe atrophic gastritis or gastric atrophy. A significant increase in the prevalences of elevated serum gastrin levels (P less than .005), low serum vitamin B12 levels (P less than .005), circulating intrinsic factor antibody (P less than .005), and anemia (P less than .025) was observed with stepwise increases in severity of atrophic gastritis. Subjects with atrophic gastritis exhibited a lower mean serum vitamin B12 level (P less than .05) and a higher mean folate level (P less than .05), but no difference was detected in mean hemoglobin levels or serum levels of iron, ferritin, retinol or alpha-tocopherol. It is concluded that serum pepsinogen I and pepsinogen II levels can be used to determine the prevalence and severity of atrophic gastritis, that atrophic gastritis is common in an elderly population, and that atrophic gastritis is associated with vitamin B12 deficiency and anemia. Further, higher folate levels in atrophic gastritis may be related to an accumulation of 5-methyl tetrahydrofolate in serum due to vitamin B12 deficiency and/or greater folate synthesis by the intestinal flora resulting from bacterial overgrowth secondary to hypo- or achlorhydria.
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PMID:Fundic atrophic gastritis in an elderly population. Effect on hemoglobin and several serum nutritional indicators. 377 80

Cobalamin deficiency must be suspected in all patients with unexplained neuropsychiatric symptoms or unexplained anemia. Special attention should be paid to patients at risk of developing cobalamin deficiency such as elderly people, vegetarians, HIV-infected patients, patients with gastrointestinal diseases and patients with autoimmunity or a family history of pernicious anemia. The assays aimed to answer the question: does this patient suffer from cobalamin deficiency, include analysis of P--cobalamins and analyses of the metabolites that accumulate upon cellular cobalamin deficiency, P--methylmalonate and P--homocysteine. P--cobalamins or especially a fraction of P--cobalamins, P--TC cobalamins are markers for latent cobalamin deficiency. An increased concentration of P--methylmalonate that decreases upon injection of cobalamin indicates overt metabolic cobalamin deficiency. The same holds for P--homocysteine but this analysis is less specific than P--methylmalonate. We suggest that either assay of P--cobalamins or P--methylmalonate is employed as screening test for cobalamin deficiency, and that further tests are performed only if the initial test in combination with the clinical picture gives an unclear answer. Once cobalamin deficiency has been diagnosed, the cause for the deficiency should be sought and the patient should be treated for life. Cobalamin absorption tests such as the Schilling test are considered of limited use. Gastric atrophy is likely to be present in patients with increased P--gastrin or decreased P--pepsinogen A. However, this condition can be diagnosed also by upper gastrointestinal endoscopy.
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PMID:How to diagnose cobalamin deficiency. 770 Dec 43

Mucolipidosis type IV is an autosomal recessive lysosomal storage disease of unknown etiology that causes severe neurological and ophthalmological abnormalities. In an attempt to obtain insight into the nature of the metabolic abnormality in this disorder, we prospectively evaluated 15 consecutive patients, aged 2 to 23 years, over a period of 22 months. The finding of iron deficiency in some of the patients led us to the discovery that all patients but one had markedly elevated blood gastrin levels. None had vitamin B12 deficiency. Gastroscopy in three patients showed normal gross appearance of the mucosa in two patients, 4 and 7 years old, and mucosal atrophy in a 22-year-old. Parietal cells were present in normal numbers and contained large cytoplasmic inclusions that were confirmed immunohistochemically to be lysosomal in nature. Other gastric epithelial cells appeared normal. Parietal cells contained very few tubulovesicular membranes, suggesting cellular activation, whereas apical canaliculi appeared relatively nonactivated. Both subunits of the parietal cell H+/K+-ATPase were present, and both partially colocalized with f-actin at the apical membrane. We conclude that patients with mucolipidosis type IV are constitutively achlorhydric and have partially activated parietal cells. We hypothesize that the defective protein in this disease is closely associated with the final stages of parietal cell activation and is critical for a specific type of cellular vacuolar trafficking between the cytoplasm and the apical membrane domain.
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PMID:Constitutive achlorhydria in mucolipidosis type IV. 944 10

In the great majority of cases vitamin B12 deficiency is caused by chronic atrophic gastritis. This study has compared several different tests for the identification of patients for whom substitution therapy is needed or warranted. It is concluded that serum tests reflecting the state of the gastric body mucosa (serum pepsinogen A combined with serum gastrin or serum pepsinogen C) appear to be the logical first step in the workup of these patients in terms of high sensitivity and superior specificity as compared with other tests.
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PMID:[Evaluation of analytic test methods. Stomach-intestines status is the best diagnostic method in suspected vitamin B12 deficiency]. 1103 56

On the basis of the levels of serum pepsinogen I (S-PGI) and gastrin-17 (S-G-17) as well as Helicobacter pylori - antibodies assayed from a blood sample it is possible to establish with high sensitivity and specificity whether the patient has gastritis, whether the gastritis is atrophic or not and in which part of the stomach the atrophic changes are located. The test enables the identification of patients whose risk of gastric cancer, of the consequences of vitamin B12 deficiency (e.g. elevated levels of homocysteine) or of peptic ulcer is considerably increased and who can then undergo gastroscopy. It also facilitates the diagnosis of non-atrophic Helicobacter gastritis enabling treatment before endoscopy.
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PMID:Diagnosis of atrophic gastritis from a serum sample. 1238 11

A case of peripheral neuropathy in a patient with diabetes who had atypical clinical findings is presented. Because of the atypical initial manifestations and short duration of insulin-dependent diabetes, another cause of the neuropathy was suspected. The presence of vitiligo, hypothyroidism, and diabetes prompted a search for evidence of pernicious anemia. Despite a normal blood cell count, the diagnosis of pernicious anemia was confirmed on the basis of an increased serum gastrin level and antiparietal cell antibody titer. Treatment with vitamin B12 resulted in an arrest, but not a reversal, of the signs of peripheral neuropathy. In patients with diabetes, vitamin B12 deficiency should be suspected; its early diagnosis and treatment are important in minimizing neurologic damage.
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PMID:Nondiabetic neuropathy in a patient with diabetes. 1525 65

On the basis of the levels of serum pepsinogen I (S-PGI) and gastrin-17 (S-G-17) as well as Helicobacter pylori antibodies it is possible to establish with high sensitivity and specificity whether the patient has gastritis, whether the gastritis is atrophic or not and in which part of the stomach the atrophic changes are located. The tests enable the identification of patients whose risk of gastric cancer, consequences of vitamin B12 deficiency or peptic ulcer is increased considerably and who should therefore undergo gastroscopy. They also facilitate diagnosis of non-atrophic Helicobacter gastritis enabling treatment before endoscopy.
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PMID:Diagnosis of atrophic gastritis from a serum sample. 1648 67

Pernicious anemia is a megaloblastic anemia caused by vitamin B12 deficiency, and is the end-stage of autoimmune gastritis that typically affects persons older than 60 years. It is the most common cause of vitamin B12 deficiency. Pernicious anemia can also be diagnosed concurrently with other autoimmune diseases. We report the occurrence of megaloblastic anemia in a 22-year-old woman with chronic autoimmune thyroiditis for 10.5 years. Recently, she presented with microcytic anemia, and iron deficiency anemia was diagnosed initially. After administration of ferrous sulfate, macrocytic anemia was revealed and vitamin B12 deficiency was detected. Pernicious anemia was highly suspected because of the endoscopic finding of atrophic gastritis, and high titer of antigastric parietal cell antibody, as well as elevated serum gastrin level. After intramuscular injections of hydroxycobalamine 100 microg daily for 10 days, and monthly later, her blood counts returned to normal.
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PMID:Coexistence of megaloblastic anemia and iron deficiency anemia in a young woman with chronic lymphocytic thyroiditis. 1705 Jan 98


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