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The effect of 4 mg oral naloxone on preoperative gastric volume and pH of gastric aspirate was studied in a double-blind, randomized study. Twenty patients received 10 ml of naloxone (4 mg) mixed with 10 ml of orange juice, and 20 patients received 10 ml of isotonic saline mixed with 10 ml of orange juice, 2 h before surgery. Gastric content was obtained immediately after intubation of the trachea. No significant difference in gastric volume and pH of gastric aspirate was found between the two groups. It is concluded that naloxone does not affect gastric emptying and gastric acid secretion to a degree great enough to protect against aspiration of gastric contents into the lungs.  相似文献   
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The structural requirements for the gastric cytoprotective activity of several sesquiterpene lactones are reported. A theoretical-experimental study on the potentially active centers is carried out. The biological evaluation of reduced analogues and the simulation of the molecular interactions between these compounds and an endogenous cysteine residue suggest that the presence of a non sterically hindered Michael acceptor seems to be an essential structural requirement for the cytoprotective activity in this family of compounds. This observation suggests that cytoprotection is mediated through a Michael reaction between the sulfhydryl-containing peptides of the mucosa and Michael acceptors present in the molecules under study. This mechanism of action is in addition to and distinct from the one proposed in our previous paper, namely, that these sesquiterpenes stimulate endogenous synthesis of prostaglandins.  相似文献   
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OBJECTIVE: To better understand hepatitis C viropathies and seroprevalence by performing an epidemiologic analysis of pregnant women seropositive for antibody against hepatitis C. METHODS: We studied 1013 consecutive obstetric patients at Parkland Memorial Hospital who gave informed consent for detailed interviews and serotesting. Sera were analyzed for antibody to the hepatitis C virus using both C100-3 and RIBA-4 assays. Neonatal assessment was carried out in the immediate postpartum period. RESULTS: Hepatitis C antibody was detected in 2.28% (N = 23) of the 1005 women in whom analysis was completed. Factors associated with seropositivity included intravenous (IV) drug use, sexually transmitted diseases, hepatitis B infection, maternal age greater than 22.5 years, increased parity (eg, greater than 2.1), history of transfusion, and three or more different lifetime sexual partners or a sexual partner who used IV drugs. Maternal and neonatal outcome was not different between hepatitis C antibody-positive and -negative groups. CONCLUSIONS: Epidemiologic data are consistent with sexual and parenteral modes of transmission. Women with hepatitis C antibody did not have excessive perinatal complications compared with antibody-negative women. A model protocol and cost analysis for screening pregnant women for hepatitis C infection are presented. However, routine screening for hepatitis C is not advocated.  相似文献   
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