Expression of the class I alcohol dehydrogenase gene in developing rat fetuses.

Class I alcohol dehydrogenase (ADH) is the principal enzyme responsible for ethanol oxidation in mammals. Although primarily regarded as an enzyme that functions in the adult, Class I ADH has been reported to be present in fetal tissues. By in situ hybridization, we demonstrated the tissue localization of the Class I ADH transcript in developing rat fetuses between Days 15 (E15) and 18 (E18) of gestation. Abundant transcripts were present in epidermis, lung, and urinary bladder. In these tissues, the messages were localized primarily to the superficial layer of the epithelium and increased with development. The liver exhibited significant signals only in the E18 fetus, when parenchymal hepatocytes first appeared. The E15 and E16 small intestines, with their epithelium arranged in a stratified fashion, displayed signals in the submucosal mesenchymal layer. By E17, a rearrangement of the intestinal epithelium into an almost monolayer configuration was observed. This change was associated with a redistribution of the ADH transcript to the surface of the epithelium. Further relocation of the messages was noted in the adult small intestine, in which they became concentrated in the base of the crypt. These findings indicate that expression of the rat class I ADH gene follows a dynamic course in specific epithelial tissues during fetal development. In addition, the apparent superficial localization of the ADH message in most of these tissues suggests that ADH functions in metabolizing either endogenously or exogenously derived alcohol substrates present in the fetal environment.

Management of malignant esophageal stricture with esophageal dilation and esophageal stents.

Esophageal dilatation and endoprosthesis insertion are very useful techniques in the palliation of malignant esophageal strictures. Patients with tracheoesophageal fistula or tumors poorly responsive to dilation or other therapies will achieve benefit from esophageal stent placement. Although further studies are needed, it appears that the use of expansile metallic stents may be advantageous compared with the standard plastic stents.

A filing system for the gastroenterology/hepatology consultant.

OBJECTIVES: A personal reprint collection is useful to practicing gastroenterologists. Its utility is enhanced when access to information is ensured through an efficient method of filing and retrieval. Our objective was to develop a filing system appropriate for use by gastroenterology/hepatology consultants. METHODS: Analyzing the shortcomings of computer-based and noncomputer-based filing systems, we developed a low-cost, intuitive (organ system-based) filing order with an up-to-date cross-referencing index. Authoritative gastroenterology and hepatology textbooks were consulted to ensure completeness. RESULTS: The filing system developed is user-friendly, expandable, and can be initiated with little investment of material or time. The system requires no computer and is easily learned. Moreover, this structure can organize both individual and departmental/divisional reprint collections and serve as a template for gastroenterology and hepatology textbooks. CONCLUSION: The organ system-based filing scheme presented is a valuable resource for gastroenterology/hepatology consultants.

Does intrabiliary pressure predict basal sphincter of Oddi pressure? A study in patients with and without gallbladders.

BACKGROUND: The endoscopic measurement of sphincter of Oddi pressure is a technically difficult procedure requiring significant expertise. Intrabiliary pressure is technically easy to measure. Furthermore, since it is believed that the pathogenesis of pain in patients with sphincter of Oddi dysfunction is attributable to increased intrabiliary pressure, its measurement may be more clinically relevant than measurement of sphincter of Oddi pressure. METHODS: Intrabiliary pressures were blindly measured in 54 patients who had sphincter of Oddi manometry for abdominal pain. RESULTS: In all patients intrabiliary pressure was significantly higher in patients with sphincter of Oddi dysfunction than those with normal sphincter of Oddi pressure (19.6 +/- 2.2 vs 9.6 +/- 1.2 mm Hg; p < 0.01). These findings were similar when patients were stratified according to presence of intact gallbladder (19.3 +/- 1.6 vs 8.8 +/- 1.4; p < 0.01) and to patients without a gallbladder (20.1 +/- 3.8 vs 12/1 +/- 1.3; p = .034). There was positive correlation between intrabiliary pressure and sphincter of Oddi basal pressure. This correlation was significant both in patients with and without gallbladders. CONCLUSIONS: These data suggest that increased intrabiliary pressure may be a useful surrogate marker of sphincter of Oddi dysfunction.

Biliary manometry in swine: a unique endoscopic model for teaching and research.

Biliary manometry, the "gold standard" for the diagnosis of sphincter of Oddi dysfunction, is associated with technical and methodological problems. The lack of a suitable experimental model has hindered efforts to solve these problems. We report here on the first practical animal model for endoscopic biliary manometry, similar in technique to the procedure in humans. Piglets were sedated and intubated with a standard human duodenoscope. A standard water-perfused manometry catheter was inserted into the bile duct. The biliary sphincter was identified by a zone of high-pressure activity with superimposed phasic contractions. The sphincter responded normally to the administration of cholecystokinin and morphine by relaxation and contraction, respectively. This model should be useful for training in biliary manometry, and facilitate technical innovations in the field. Since it is relatively atraumatic, it may also be better than existing surgical models for studying the normal physiology and pharmacology of the sphincter of Oddi.

Cellular localization of the class I alcohol dehydrogenase transcript in adult rat tissues.

The mammalian class I alcohol dehydrogenase is the principal enzyme responsible for ethanol metabolism. While it is regarded primarily as a liver-specific enzyme, class I alcohol dehydrogenase is known to be present in a number of extrahepatic tissues. The purpose of the current study is to define the tissue and cellular distribution of the dehydrogenase transcript in four rat tissues previously shown to contain high levels of mRNA: the liver, the proximal small intestine, the colon and the testis. Localization of the transcript was examined in formalin-fixed, paraffin-embedded rat tissues by in situ hybridization using radioactively labelled antisense rat alcohol dehydrogenase RNA probe. In the liver, the dehydrogenase message is localized primarily to the perivenous hepatocytes. In the proximal small intestine and the colon, the message follows a vertical gradient of distribution along the crypt-villus and the crypt-surface epithelium axes, respectively, with the base of the crypt exhibiting the greatest concentration. In the testis, the message is localized primarily to cells in the interstitium. These findings illustrate a highly compartmentalized nature of distribution of the class I alcohol dehydrogenase transcript in the tissues studied and may help to elucidate the metabolic functions of this enzyme in these tissues.