Esophagus development

Benedict EB (1941) Carcinoma of the esophagus developing in benign stricture. New England Journal of Medicine 224 408-412. 

The splanchnic system drains venous blood from the GI tract to the liver. In portal hypertension there is increased resistance to drainage from the originating organ so collateral vessels (varices) develop in the esophagus, stomach, and rectum to compensate for the increased blood volume. Varices divert blood meant for hepatic circulation back to the systemic circulation this has the unintended deleterious effect of decreasing clearance of medications and potential toxins through loss of first-pass metabolism. Varices are weak superficial vessels, and any additional increase in pressure can cause these vessels to rupture and bleed.15... 

The key factor in the development of GERD is the abnormal reflux of gastric contents from the stomach into the esophagus. 

Problems with other normal mucosal defense mechanisms may also contribute to the development of GERD, including prolonged acid clearance time from the esophagus, delayed gastric emptying, and reduced mucosal resistance. 

The issue of surface properties in tablets is also important and, surprisingly, small flat tablets can cause problems. In the development of a risedronate product, we needed to develop a procedure that was able to discriminate between alternative formulations. The key conditions necessary to differentiate among products with respect to the ease of swallowing was to dose the unit with one mouthful of water—30 mL. Using this procedure we demonstrated that small, uncoated, shallow convex-shaped tablets (9.5 mm diameter) were arrested in the esophagus more often than the final design of the formulation—an oval of 5.7 x 11.5 mm (2). In 5 out of 30 cases, esophageal transit of the smaller tablet was slower (6). 

The gastrointestinal system of zebrafish presents clear differences from the human system. The zebrafish does not possess a stomach, the intestine is continuous with the pharynx through a short esophagus, and no sphincters are present [61]. However, zebrafish have most of the cell types observed in the small intestine -absorptive, endocrine, goblet, and interstitial cells of Cajal, although Paneth cells are absent. Gut contractions are under the control of the enteric nervous systems, which respond to different pharmaceuticals in similar way as the mammalian counterpart. For example, zebrafish embryos can be used as predictor of emetic response to pharmaceuticals, one of the most commonly reported clinical adverse effects to be considered in the development of new dmgs [61]. 

Eosinophils develop in the bone marrow where they also mature. They are then released into the blood followed by their migration into the tissue spaces. Eosinophils comprise 1-5% of blood leukocytes in nonatopic individuals. They are present in thymus, spleen, lymph nodes, uterus and lower GI tract. Under normal conditions, they are not present in the skin, lungs or esophagus. They can live up to 72 h in the tissue. Their migration to the site of inflammation or parasitic infection is directed by leukotriene B4 and chemokines eotaxin (CCL11) and RANTES (CCL5). They... 

Think twice before pouring this stuff down your drain or spraying in your oven. It s a strong, caustic substance that causes severe corrosive damage to eyes, skin, and mucous membranes, as well as the mouth, throat, esophagus, and stomach. Blindness is reported in animals exposed to as little as 2% dilution for just one minute. Skin is typically damaged by 0.12% dilutions for a period of one hour. Tests with healthy volunteers exposed to the chemical in spray from oven cleaners showed that respiratory tract irritation developed in two to fifteen minutes. Sodium hydroxide is included as a toxic chemical on the EPA s Community Right-to-Know list. It is also a controlled substance in the workplace, and OSHA has set limitations on concentrations in the air. 

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