Stomach and Duodenum

Helicobacter pylori is a spiral shaped bacterium that lives in the stomach and duodenum (the section of intestine just below the stomach). Most bacteiia cannot live in the stomach since the environment is too acidic to survive. However, Helicobacter pylori has large amounts of urease, which converts urea to ammonia and carbon dioxide. Ammonia is used to maintain the periplasmic and cytoplasmic pH of the bacterium at neutrality, so this bacterium can survive. Helicobacter pylori causes peptic... 

Tyssandier, V. et al., Processing of vegetahle-home carotenoids in the human stomach and duodenum. Am. J. Physiol. Gastrointest. Liver Physiol, 284, G913, 2003. 

The tips of villi have the lowest pHm values, whereas the crypt regions have pHm > 8 values [70]. Most remarkable was that an alkaline microclimate (pHm 8) was observed in the human stomach, whose bulk pHfo is generally about 1.7. In the stomach and duodenum, the near-neutral microclimate pH was attributed to the secretion of HCO3 from the epithelium [70]. 

Abbot, F. K., M. Mack and S. Wolf, The Action of Banthine on the Stomach and Duodenum of Man with Observations of the Effects of Placebos , Gastroenterology 20 (1952)... 

Gastrointestinal sphincters are formed where the circular layer of smooth muscle is thickened. Sphincters occur at several points along the tract. Their function is to limit the movement of food materials from one region to another. For example, the pyloric sphincter found between the stomach and duodenum of the small intestine plays an important role in limiting the rate of gastric emptying. Sphincters undergo tonic contractions that may be sustained for minutes or hours. 

Drugs of this kind are used for treating stomach and duodenum ulcers and hypersecre-tive conditions. 

Cimetidine is used for treating ulcer problems of the stomach and duodenum and for other conditions accompanied by an elevation of acidity and excess secretion of gastric juice. It is used for preventing injuries and the blood flow of the upper regions of the gastrointestinal tract. Synonyms of this drug are tagamet, cinamet, and belomet. 

Ranitidine is a second-generation H2-receptor-blocking drug. Like cimetidine, ranitidine suppresses both basal and stimulated hydrochloric acid produced by food, histamine, gastrin, and acetylcholine. It simultaneously reduces pepsin activity and is used for treating stomach and duodenum ulcers as well as other conditions accompanied by elevated acidity of the gastrointestinal tract. Synonyms of this drag are zantac, azantac, raniplex, ranidil, and others. 

It is used for pellagra (avitaminosis PP), atherosclerosis, liver disease, stomach and duodenum ulcers, and prolonged, nonhealing wounds and ulcers. Synonyms of this drag are niconacid, pemivit, enzycol, niacin, and others. 

Bi2 are only about 2 meg, it would take about 5 years for all of the stored vitamin B12 to be exhausted and for megaloblastic anemia to develop if Bi2 absorption were stopped. Vitamin B12 in physiologic amounts is absorbed only after it complexes with intrinsic factor, a glycoprotein secreted by the parietal cells of the gastric mucosa. Intrinsic factor combines with the vitamin Bi2 that is liberated from dietary sources in the stomach and duodenum, and the intrinsic factor-vitamin Bi2 complex is subsequently absorbed in the distal ileum by a highly selective receptor-mediated transport system. Vitamin Bi2 deficiency in humans most often results from malabsorption of vitamin B12 due either to lack of intrinsic factor or to loss or malfunction of the specific absorptive mechanism in the distal ileum. Nutritional deficiency is rare but may be seen in strict vegetarians after many years without meat, eggs, or dairy products. 

Helicobacter pylori is a bacterium that lives in the human stomach and duodenum. The bacterium is generally recognized as one of the etiological agents of peptic ulcer. Therefore, it is generally accepted that ulcer patients with H. pylori infection require treatment with antimicrobial agents in addition to anti-secretory drugs, whether on first... 

FIGURE 2-3 Effect of phi and ionization on absorption of drugs from the gastrointestinal tract. Weak acids and bases are absorbed from the stomach and duodenum, respectively, when they are in their neutral, nonionized form. 

The appearance of mass movements after meals is caused at least partially by gastrocolic and duodenocolic reflexes. These reflexes result from distension of the stomach and duodenum. They can take place, although with decreased intensity, when the autonomic nerves are removed therefore, it is probable that the reflexes are basically transmitted through the myenteric plexus, although reflexes conducted through the autonomic nervous system probably reinforce this direct route of transmission. 

Helicobacter pylori infections lead to chronic inflammatory condition of mucous membrane in the stomach and duodenum, thus they may contribute to allergization (Matysiak-Budnik et al., 2003). 

Several reports were available in which the amount of ingested chromium compound could be estimated. A 17-year-old male died after ingesting 29 mg chromium(VI)/kg as potassium dichromate in a suicide. Despite attempts to save his life, he died 14 hours after ingestion from respiratory distress with severe hemorrhages. Caustic burns in the stomach and duodenum and gastrointestinal hemorrhage were also found (Clochesy 1984 Iserson et al. 1983). 

Bioconversion Biodetoxication Removal of Escherichia coli (P450 Stomach and duodenum Decrease of the mutagenic... 

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