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101.
BACKGROUND & AIMS: Previous studies have shown that nitric oxide synthesis inhibition corrects the hyporesponsiveness to vasoconstrictors present in the mesenteric vascular bed of portal- hypertensive rats. The origin of this elevated NO production, whether endothelial or muscular, is unknown. The aim of this study was to evaluate the role of vascular endothelium in the hyporesponsiveness to methoxamine (MTX) in the mesenteric vascular bed of portal vein-ligated (PVL) and cirrhotic rats. METHODS: Endothelial denudation was achieved using a combined treatment of cholic acid and distilled water. RESULTS: Compared with the respective control groups, PVL rats showed a reduced vascular response to MTX. Similar results were obtained in cirrhotic animals. The presence of ascites was associated with a more severe reduction in the response to MTX. Removal of the endothelium completely corrected the vascular hyporesponsiveness of PVL, cirrhotic nonascitic, and ascitic animals. In these experiments, acetylcholine-mediated vasodilation was practically absent whereas that of sodium nitroprusside was potentiated, which indicates a successful elimination of the endothelium and the preservation of smooth muscle function. Immunostaining for NO synthase isoforms revealed the presence of endothelial NO synthase protein in healthy and PVL rats exclusively in the endothelium. CONCLUSIONS: The mesenteric vascular hyporesponsiveness to MTX present in these models of liver diseases and portal hypertension is solely due to endothelium-dependent factors. (Gastroenterology 1996 Dec;111(6):1627-32) 相似文献
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A computer-aided system to estimate bone age based on Fourier analysis was assessed by reference to the original radiographs used to produce the Tanner-Whitehouse 2 (TW2) standards for the radius, ulna and short finger bones. The computer-aided system involved matching a template of each bone to the scanned image of the radiograph. The computer then generated a stage of bone maturity, individual and total bone scores and a value for bone age. The bone ages assessed by the computer-aided system were no different from the original TW2 reference values, indicating the applicability of the system. The system was used to assess the bone ages of tall Dutch girls, and the results obtained were compared with more traditional assessments made by an experienced rater. For the radiographs from the tall girls, there was good agreement for individual bones between this method and the traditional assessment by the rater, but less agreement for the total 13-bone score and bone age. 相似文献
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RYJ Tamminga WA Kamps NM Drayer GB Humphrey 《Acta paediatrica (Oslo, Norway : 1992)》1992,81(1):61-65
In four groups of patients with acute lymphoblastic leukaemia, anthropometric variables were investigated every 3 months for 2 years. Group 1 (n = 7) was treated with a high-risk protocol, group 2 (n = 13) with a standard-risk protocol including cranial irradiation, group 3 (n = 13) with a standard-risk protocol without cranial irradiation and group 4 (n = 8) was followed after completion of treatment. A height retardation of 0.4-0.6 SD was observed during therapy in groups 1-3. A catch-up of 0.5 SD was found in group 4. The retardation of armspan was significantly larger than the retardation of sitting height when groups 1-3 were taken together. Head circumference was not affected. The anthropometric variables reflecting nutritional status showed a growth above normal during and after treatment. Corticosteroid medication and not cranial irradiation is the most likely explanation for our findings. 相似文献
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Chronic liver disease: evaluation by magnetic resonance 总被引:4,自引:0,他引:4