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891.
P A Rittenhouse E A Bakkum L D Van de Kar 《The Journal of pharmacology and experimental therapeutics》1991,259(1):58-65
DOI [(+/-)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane HCI] is a serotonin (5-HT1C/5-HT2) agonist, with potent cardiovascular effects. The purpose of the present studies was to determine the identity and location of the 5-HT receptor subtype(s) mediating the renin and blood pressure responses to DOI. Injection (i.p.) of DOI to conscious male rats elevated plasma renin activity in a dose-dependent manner. The 5-HT1C/5-HT2 antagonist ritanserin completely blocked the DOI-induced increase in plasma renin activity. In order to distinguish the 5-HT2- from the 5-HT1C- mediated effect of DOI, spiperone was administered before DOI. Low doses of spiperone (0.01 and 0.1 mg/kg, s.c.) significantly reduced the renin response to DOI. Because spiperone has a higher affinity for 5-HT2 than 5-HT1C receptors, these data suggest that DOI stimulates renin secretion through 5-HT2 receptors. To separate central from peripheral 5-HT receptors, we injected DOI into rats pretreated with saline or xylamidine, a 5-HT2 antagonist which does not cross the blood-brain barrier. Xylamidine produced a shift to the right and suppression of the maximal effect of DOI on plasma renin activity, suggesting a role for peripheral 5-HT2 receptors in the effect of DOI. On the other hand, i.c.v. administration of DOI, using doses lower than the peripherally effective doses, caused a significant elevation of plasma renin activity at 200 micrograms/kg. These experiments suggest that DOI's elevation of plasma renin activity has both peripheral and central sites of action.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
892.
D L Renfrew G Y el-Khoury T E Moore M H Kathol C G Whitten C W Walker M A Fraser-Hill 《Investigative radiology》1991,26(11):1019-1023
Although general suggestions have been made regarding a radiology residency curriculum, no specific list of entities has been offered. Over the past ten years, we have developed a resident-run morning conference in musculoskeletal radiology that is supervised by faculty and covers a specific curriculum. We offer our curriculum as an example that may assist other departments in developing their own curricula. 相似文献
893.
894.
895.
Development of the genital and urinary systems is interwoven. Developmental abnormalities may cause problems in both systems, although the presenting problem may be ambiguous genitalia, hypospadias, undescended testis, or a urinary tract infection. The primary care physician must understand the underlying significance of pediatric urologic problems and seek appropriate consultation in a timely manner. 相似文献
896.
Trichomonas vaginalis was incubated with bacteria for 30 min. After centrifugation of Staphylococcus aureus, incubation of T. vaginalis was continued for 40 min., 120 min. and 6 hrs. It was found that bacteria have been intensively phagocytated through whole surface of protozoan. Phagosome with bacteria at different stages of degradation, up to defecation of undigested residues were observed. It was observed that some bacteria, apparently not susceptible to digestion, were immersed directly in cytoplasm (outside vacuoles). 相似文献
897.
Linkage mapping of a mouse gene, iv, that controls left-right asymmetry of the heart and viscera. 总被引:1,自引:0,他引:1
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M Brueckner P D''''Eustachio A L Horwich 《Proceedings of the National Academy of Sciences of the United States of America》1989,86(13):5035-5038
Inherited single gene defects have been identified in both humans and mice that lead to loss of developmental control over the left-right asymmetry of the heart and viscera. In mice the recessively inherited mutation iv leads to such apparent loss of control over situs: 50% of iv/iv mice exhibit situs inversus and 50% exhibit normal situs. The affected gene product has not been identified in these animals. To study the normal function of iv, we have taken an approach directed to the gene itself. As a first step, we have mapped iv genetically, by examining its segregation in backcrosses with respect to markers defined by restriction fragment length polymorphisms. The iv locus lies 3 centimorgans (cM) from the immunoglobulin heavy-chain constant-region gene complex (Igh-C) on chromosome 12. A multilocus map of the region suggests the gene order centromere-Aat (alpha 1-antitrypsin gene complex)-(11 cM)-iv-(3 cM)-Igh-C-(1 cM)-Igh-V (immunoglobulin heavy-chain variable-region gene complex). 相似文献
898.
The action of papain and bromelain, prepared over a pH range from 4.6 to 8.6, was evaluated for the ability to render red cells agglutinable by five incomplete antibodies of differing blood group specificities using a two-stage technique. The optimal pH for treatment of red cells by activated papain or bromelain was between 5.4 and 5.8. Above this pH range, a fall in serological sensitivity was apparent which was much more pronounced with papain than with bromelain. The optimal pH for enzyme treatment of red cells can be achieved in two-stage techniques, but not in one-stage techniques due to the buffering effect of serum proteins. 相似文献
899.
900.
A double-stemmed MTP joint silastic implant has been described that acts as a flexible spacer for a number of pathologic conditions that affect the lesser metatarsophalangeal joints. Preliminary results suggest that this is a feasible alternative to joint destructive procedures with advantages over previously described implants. 相似文献