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961.
Stimulation of the vagal trunk in cats anesthetized with pentobarbital sodium produced a contractile response of the stomach during stimulation (initial contraction). Pretreatment with either hexamethonium (0.3 to 30 mg/kg, i.v.) or gallamine (1 to 100 mg/kg, i.v.) dose-dependently produced a delayed contraction, following the initial contraction after stimulation. After the administration of either hexamethonium or gallamine produced a maximum delayed contraction, then an additional dose of gallamine or hexamethonium was administered. The subsequent treatment further augmented the delayed contraction. The results indicate that gallamine induced the delayed contraction by a mechanism different from hexamethonium.  相似文献   
962.
Arachidonic acid metabolites (eicosanoids) have major effects on bone but their role is unclear. Many are known to stimulate bone resorption in organ culture, but paradoxically, previous work has suggested that at least some of them act as direct inhibitors of osteoclastic function. In an attempt to clarify the role of eicosanoids in bone physiology, we have defined the duration of action and relative potencies of prostaglandin (PG) E1 and E2 and have extended the range of eicosanoids tested on isolated osteoclasts. We have found that PGE1 and PGE2 inhibited bone resorption by isolated osteoclasts for at least 6 h. Inhibition was followed by recovery to control, not supranormal levels. Bone resorption was inhibited in the range 10(-5)-10(-9) M for PGE1 and PGE2, and the rank order as resorption inhibitors was PGE1 greater than 6-keto PGE1 greater than PGE2 greater than PGA2 greater than PGB2. None of the products of lipoxygenase metabolism showed a significant direct effect. The effects of PGE1 and PGE2 were not antagonistic. Prostaglandin production does not seem to be implicated as a second messenger for the action of calcitonin. Although inhibition of osteoclasts by PGs was less prolonged than that observed in the presence of calcitonin, the sensitivity of osteoclasts to inhibition by PGs, and the duration of the effect without subsequent direct stimulation, suggests that inhibition of osteoclastic resorption is a major physiological role of PG production in bone.  相似文献   
963.
Localization of 3H-proline, 35S-sulfate and 3H-glucosamine was studied by autoradiography in the rat cornea following the removal of the epithelium. The three labeling chemicals were injected into the anterior chamber of rats, one chemical in each rat, 24 hours after the removal of the epithelium. Animals were sacrificed at various intervals up to 7 days after the injection. The silver grains of 35S-sulfate incorporated into the re-covered epithelium gradually shifted into the stroma. On the other hand, the 3H-glucosamine tended to move toward the epithelial cell membrane and the superficial layer of the epithelium. The 3H-proline incorporated in the epithelium remained in the cells without movement. These results suggest that the 35S-sulfate in the epithelium shifted into the stroma as 35S-phosphoadenosine-phosphosulfate [35S-PAPS] before sulfation of glycoconjugates occurred in the epithelium. A large amount of 3H-glucosamine was utilized as a component of low-sulfated glycoconjugates in the epithelial cell membrane and other cell-coating substances.  相似文献   
964.
The effects of different amounts of dietary zinc on the Zn absorption rate and on Zn, calcium and magnesium concentrations in tissues of MOPC 104E tumor-bearing Balb/c mice were determined. The Zn absorption rate was inversely related to the amounts of Zn in their diets and was lower than that of nontumor-bearing control mice fed a laboratory mice chow. Zn concentrations of tumor-bearing mice were also low compared with control mice but tumor Zn concentrations, regardless of the concentrations of Zn in the diets, were higher than those of normal tissues of the host other than the pancreas. Ca concentrations in tumor and tissues of tumor-bearing mice were higher than in control animals but Mg concentrations in tissues of tumor-bearing mice appeared to be similar to those of control mice. Results suggest that tumor-bearing mice have a lower intestinal Zn absorption capacity and a higher Zn uptake rate causing other tissues to become hypozincemic and hypercalcemic.  相似文献   
965.
Dihydroxyacetone (DHA), a browning agent, protects photosensitive rats and humans against long ultraviolet radiation (UVA, 320-400 nm) and visible (blue) light. The photoprotective efficacy of DHA and structurally similar compounds was assessed as prevention of edema in the paws of psoralen-sensitized rats, after exposure to blacklight fluorescent lamps. Methylglyoxal produced a yellow-brown color and provided nearly the same protection as DHA, whereas monohydroxyacetone did not color the skin and afforded little or no protection. Glyceraldehyde provided a moderate amount of protection, which was enhanced by prior exposure of the agent to alkaline pH. A solution of 5-hydroxymethylfurfuraldehyde was yellow and provided minimal protection by staining the skin rather than browning it. We conclude that the ability to produce a brown color in skin is a useful criterion for screening compounds for photoprotective efficacy against UVA radiation.  相似文献   
966.
A clinical phase I study for T-2588 was carried out in 25 healthy male volunteers. Each volunteer received T-2588 in one of the following doses: 100 mg capsule or tablet as a single oral administration in fasting or non-fasting state, 200 or 400 mg capsule as a single oral administration in non-fasting state or 300 or 600 mg daily for 14 approximately 15 days as a repeated administration in non-fasting state. The results are summarized below. No subjective or objective adverse effects were noted after a single oral administration. But repeated dose of 300 mg daily for 15 days and 600 mg daily for 14 days brought about abdominal distension in 1 case and soft stool in 1 case, respectively. As an abnormal change in clinical laboratory findings, 1 case with slight increase in transaminase after a single administration and 3 cases with slight increases in transaminase after repeated doses were observed. Time to reach a maximum concentration of T-2525 in blood (Tmax) was longer in subjects at non-fasting states than subjects in fasting states. Maximum blood concentration was lower in the latter than in the former. Urinary excretion rate in 8 hours after an oral administration was 19 approximately 28% and it was higher in non-fasting subject than in fasting subject. No accumulation of T-2588 was noted after repeated doses.  相似文献   
967.
968.
A 50-year-old woman with bilateral inflammatory breast cancer (T4, N1b, M1, Stage IV) underwent right extended radical mastectomy and left modified radical mastectomy following pre-operative administration of carcinostatics (ADM, 5-FU) and irradiation. However, tumor recurrence was observed at the skin and right pleural cavity after the operation. Adriamycin-containing combination chemotherapy and radiation therapy were performed, but no significant response was obtained. CDDP was then administered intravenously at a daily dose of 62.5 mg/m2 at intervals of 60 days. The pleural effusion disappeared and the extent of skin metastasis was reduced, resulting in partial response which lasted for 90 days. The serum CEA level decreased from 13.1 ng/ml to 2.3 ng/ml. As the side effects of this therapy, slight nausea, vomiting and general fatigue were observed. This result suggested that CDDP is an effective drug for inflammatory breast cancer.  相似文献   
969.
This research was designed to test the extent to which health education and health services administration students' perceptions of their roles as professionals matched the expectations of professional faculty. These perceptions were found to match in general. However, doubt was cast on the extent to which internships or practicums contributed to this result, since there was no change in student responses between the beginning of the junior year and end of the senior year, a period which includes fieldwork and most of the professional coursework presumed to influence professional development. Additional research is required to test this result with other student populations in other health professions and identify the point at which professional role and task definitions are amenable to change.  相似文献   
970.
We investigated the effects of imaging and display conditions on the detectability of low-contrast objects in digital subtraction angiographic (DSA) images. The test images were produced by superimposition of low-contrast objects on a uniform noisy background obtained with a DSA system. We employed 18-alternative forced-choice (18-AFC) experiments and predictions based on statistical decision theory to study the dependence of the threshold contrasts of the test objects on the object size, incident x-ray exposure, display window width, and display medium. The results indicated that the threshold contrast decreased with increasing object size, and that the detectability of an object of a given size increased with increasing incident x-ray exposure and decreasing width of the display window. We found that the signal-to-noise ratio (SNR) obtained from the perceived statistical decision theory model, which includes the observer's internal noise, can accurately predict the detectability of low-contrast objects in DSA images. The threshold SNR corresponding to 50% correct detection in the 18-AFC experiments had a constant value of 3.8, in agreement with results reported previously for screen-film systems. The theoretical model will be useful for prediction of the performance of a DSA system based on its physical characteristics, and for evaluation of the tradeoff between patient exposure and diagnostic accuracy for a given DSA unit.  相似文献   
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