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1.
Summary— To investigate if the functional alterations observed in resistance arteries of spontaneously hypertensive rats (SHRs) were also present at the coronary level, in vitro experiments were performed in mesenteric resistance arteries (MRA) and in right (RIC) and left interventricular coronary (LIC) arteries taken from 15–25-week-old SHR and age-matched Wistar Kyoto rats WKYs. Using a passive extension protocol, internal diameters corresponding to 100 mmHg intraluminal pressure (D100) were determined and vessels were set up to a normalized internal diameter (0.9 D100). SHR mesenteric resistance arteries had a significantly smaller diameter compared to WKY arteries, whereas both types of SHR coronary arteries had a greater diameter compared to those of WKY rats. In arteries in the absence of contracting agonist, nitro-L-arginine (NOLA, 100 μM) induced a progressive rise in basal tone, which could be reversed by subsequent addition of L-arginine (100 μM) but not D-arginine (100 μM). When expressed as percent of maximal contractions induced by agonists (noradrenaline, NA [10 μM] in MRA; serotonin, 5-HT [10 μM], in RIC and LIC), these contractions were significantly stronger in WKY compared to SHR coronary and mesenteric resistance arteries. In NA-precontracted MRA and 5HT-precontracted coronary arteries in the presence of indomethacin (10 μM), the magnitude of acetylcholine-induced maximal relaxations (expressed as percent of maximal contractions induced by agonists) was greater in WKY compared to SHR arteries. After a 30-min incubation period, NOLA (100 μM) completely inhibited relaxations induced by acetylcholine (0.01–10 μM) in all types of precontracted arteries. Subsequent additions of sodium nitroprusside, (SNP, 10 μM) induced complete relaxations in all preparations. These results show that a basal release of NO or NO-like compound by endothelial cells is present in isolated mesenteric resistance and coronary arteries of WKY rats and SHRs. The contribution of endothelium-derived relaxing factor-nitric oxide (EDRF-NO) to arterial tone was lower in MRA compared to coronary arteries in both strains and in SHR compared to WKY arteries. In the SHR preparations, the impaired relaxation induced by acetylcholine appeared to be due to a functional alteration of the endothelium in the presence of normal reactivity of the smooth muscle cells. 相似文献
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表小檗碱对α受体的作用 总被引:2,自引:0,他引:2
表小檗碱(epiberberine,EB)是从湖北产黄连(Coptis chinensis Franch)中提取的一种生物碱,属苯喹嗪类原小檗碱,对其药理作用的研究资料甚少,未见其对α肾上腺素体作用的报道。资料表明,许多原小檗碱类化合物有α受体阻滞作用,为从该类化合物中选择 相似文献
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B G Simons-Morton T Baranowski G S Parcel N M O'Hara R C Matteson 《American journal of preventive medicine》1990,6(4):218-227
We administered a food frequency instrument to third-fifth grade students (n = 943) in four Texas schools. Comparison of foods reported on the food frequency questionnaire and on 24-hour dietary recalls (n = 7) produced a percent agreement of 83.3. The most frequent 25 foods accounted for 64.0% of food choices across all meals, 93.5% of breakfast choices, 76.4% of lunch choices, 70.5% of supper choices, and 76.0% of snack choices. Breads, milk, hamburger or steak, soda pop, tomato sauce or tomatoes, and cheese were the most frequently consumed foods. Fruits and juices accounted for 6.1% of total selections for boys and 6.6% for girls, while vegetables accounted for 15.7% of total selections for boys and 16.2% for girls. Fruit was more likely to be consumed for snacks than for meals, and vegetables were consumed in about the same frequency at lunch and supper and for snacks. We analyzed the total fat, saturated fat, and sodium content of the most frequently consumed foods. Seventeen of the top 25 foods for the total day and 13-16 for each meal or snack exceeded by at least 50% the recommended levels for fat, saturated fat, or sodium. The pattern of consumption was one of frequent consumption of a relatively small number of foods, many of which are high in fat or sodium. 相似文献
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Hazardous chemicals: psychological dimensions of the health sequelae of a community exposure in Texas. 总被引:2,自引:1,他引:1
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H H Dayal T Baranowski Y H Li R Morris 《Journal of epidemiology and community health》1994,48(6):560-568
STUDY OBJECTIVE--A chemical spill from an oil refinery exposed the local community to more than 40,000 lb of highly toxic and corrosive hydrofluoric acid. A community based symptom prevalence study found an association between exposure and physical symptoms: the psychological impact of the disaster and its potential effect on the reporting of physical symptoms is examined here. DESIGN--The study used a population based survey design consisting of two phases: phase I, the exposure phase, and, phase II, the symptom prevalence phase. SUBJECTS--In phase I, information indicative of exposure was collected on 10,811 individuals in a door to door survey of a geographically defined area. In phase II, symptom prevalence information was gathered through in-person interviews with 2509 subjects selected from the phase I census in a sampling scheme that balanced across the exposure categories with regard to age, gender, and predisposition. The refusal rate in both phases was < 5%. MEASUREMENT AND MAIN RESULTS--Stepwise logistic regression analyses were used to assess the relative predictive importance of psychological variables and hydrofluoric acid exposure in explaining the reported physical symptoms two years after the disaster. The findings show a linear relationship between the level of hydrofluoric acid exposure and the degree of psychological stress two years after the accident. High exposure had a long term (more than two years) impact on physical health for some self reported symptoms, even after controlling for the psychological impact. Some physical symptom reports, however, were better explained by psychological status than by exposure to hydrofluoric acid. The physical symptoms for which exposure was the major predictor were those for which the biological plausibility of a relationship with hydrofluoric acid exposure was direct. CONCLUSIONS--Measures of psychological status should be included in symptom studies of health sequelae to man-made disasters so that the physical effects of exposure can be more accurately assessed. 相似文献
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Pernes JM; Vitoux JF; Brenoit P; Raynaud A; Parola JL; Roth JP; Angel CY; Fiessinger JN; Roncato M; Gaux JC 《Radiology》1986,158(2):481-485
Thirty-five patients hospitalized for recent angiographically documented arterial occlusion in the legs (27 femoropopliteal arteries and eight grafts) benefited from local fibrinolytic therapy delivered at the site of the occlusion with a 4- or 5-F catheter. This therapy combined a continuous urokinase (UK) infusion of 1,000 U/kg/hour and a lysyl plasminogen (LYS-PLG) infusion of 15 microkatals every 30 minutes. Angiographically confirmed lysis was obtained in 85% of the cases. Only 3% of the patients had major and 6% had minor groin hematomas. Only two patients had concentrations of fibrinogen as low as 100 mg/dl. Intravascular infusion of UK-LYS-PLG is as effective as streptokinase. Its excellent tolerance makes it a good alternative in the treatment of acute ischemia in the lower limbs. 相似文献