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Biomedical subjects

V Dave

Publications and source records attributed to V Dave.

26 records · Page 2Linked to original sources
PubMed1991

Peripheral and renal vein renin activity in patients with renovascular hypertension due to nonspecific aortoarteritis.

The diagnostic utility of peripheral and renal vein renin estimations in relation to angiographic findings was evaluated in 13 patients with renovascular hypertension and non-specific aortoarteritis (NSAA, Gr I), in comparison with 10 patients with renal artery stenosis due to other causes (Gr II). Plasma renin activity (PRA) was measured by radioimmunoassay. Blood samples were collected after angiography from the femoral vein and renal vein on the affected side followed by sampling from the less affected or unaffected side. Renal vein renin ratio (RVRR) was calculated from renal vein renin values. The effect of captopril (25 mg oral) on blood pressure, PRA, and RVRR was examined in 8 patients from each group. Normotensive volunteers (8) with moderately low salt intake were also included in the study for comparison of twenty-four-hour urinary sodium output, peripheral PRA, and response to captopril. The mean peripheral PRA was high in both groups as compared with normotensive controls; however, the values were lower in patients with NSAA. The rise in PRA in response to captopril was insignificant in Gr I (p greater than 0.05) and RVRR greater than 1.5 was observed in 5 of 13 patients in contrast to 9 of 10 in Gr II (p less than 0.05). A paradoxical ratio, ie, (high renal vein renin levels on the less stenotic side) was noticed in 3 patients of Gr I, whereas none of the patients of GR II showed such a ratio. An improvement in RVRR after captopril was observed in 50% of patients of Gr I as compared with a marked response in all patients of Gr II.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

Disruption of FR-40 by 5-HT agonists. I. Effects of chronic imipramine or trazodone.

Doses of LSD, quipazine, 8-OHDPAT and TFMPP were established that prominently disrupted FR-40 operant response pattern in two groups of rats. Subsequently, one group received daily intraperitoneal (IP) injections of imipramine, 2.5 mg/kg, for 4 weeks, then 10 mg/kg for 2 additional weeks. The second group received 5 mg/kg/day, IP, of trazodone for the first 4 weeks, then 20 mg/kg/day for the next two weeks. For these periods and the 3 weeks after discontinuing the chronic drug treatments (washout), test doses of the 4 agonists were evaluated twice weekly in random order for their effects to decrease FR-40 reinforcements and increase pauses. No consistent, systematic changes in sensitivity to the agonist effects on FR-40 behavior were observed during chronic drug treatments, although significant effects were at times observed. However, during the washout period in the imipramine group, both LSD and 8-OHDPAT effects on reinforcements were reversed to baseline levels. The effect of 5-OHDPAT on pauses during washout in this group was also attenuated. During washout in the trazodone group, the 8-OHDPAT-induced pausing and loss of reinforcements was reduced so as to be not significantly different from baseline values. Previous studies have demonstrated antagonism of LSD- and quipazine-induced disruption of FR-40 by pretreating with the 5-HT2-selective antagonist pirenperone (28). Since chronic antidepressants down-regulate brain 5-HT2 binding sites, the effects of LSD and quipazine were expected to be attenuated, which was not the case.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Pharmacology of ivermectin.

Ivermectin is a semi-synthetic macrocyclic lactone (Fig. I) active in single low doses against many parasites - particularly nematodes and arthropods. It has been registered for animal health use since early 1985, and was earlier this year approved for human use by the French Directorate o f Pharmacy and Drugs. Of particular interest is ivermectin's potential as a micro filaricide for treatment o f onchocerciasis. Clinical trials leave little doubt about the potential o f ivermectin as a therapeutic tool for symptomatic relief from the effects o f infection with Onchocerca volvulus, and the drug is also recognized to have potential in reducing transmission o f the parasite. The manufacturers (Merck, Sharp and Dohme) recently arranged to provide the drug free o f charge to the WHO for mass trials against onchocerciasis in 12 African and Central American countries. In this article we focus on the pharmacological properties o f ivermectin, with a brief consideration of its absorption, fate, excretion and side-effects, and a discussion o f its micro filaricidal action.

Journal Article↗
PubMed1985

Synthesis of the allylic gonadal steroids, 3 alpha-hydroxy-4-pregnen-20-one and 3 alpha-hydroxy-4-androsten-17-one, and of 3 alpha-hydroxy-5 alpha-pregnan-20-one.

A method for the convenient synthesis of the recently isolated allylic gonadal steroids, 3 alpha-hydroxy-4-pregnen-20-one (3 alpha-dihydroprogesterone; 3 alpha-DHP) and 3 alpha-hydroxy-4-androsten-17-one (3 alpha-HA), was developed using 4-pregnene-3,20-dione (progesterone) and 4-androstene-3,17-dione as substrates and potassium trisiamylborohydride (KS-Selectride) as reducing agent. Similar reactions were also used for the reduction of 5 alpha-pregnane-3,20-dione to 3 alpha-hydroxy-5 alpha-pregnan-20-one (3 alpha-HP). The yields were about 15%, 50%, and greater than 90% for 3 alpha-DHP, 3 alpha-HA and 3 alpha-HP, respectively. Structures of the products, including the 3 beta-isomers and the 17 alpha-epimer, formed in these reactions were determined by NMR and mass spectroscopic methods.

Androstenedione↗
PubMed1984

Serologic and biochemical studies of a previously unclassified blood type B variant.

The designation B4 is proposed for a weak variant of type B blood found in a Salvadorian woman and her two daughters. The red cells were weakly agglutinated by anti-B and anti-A,B; the serum contained anti-B; and the saliva contained H but not B substance. Biochemical studies of the serum showed that the enzyme specified by the variant B gene had low activity and low affinity for both sugar donor and acceptor.

ABO Blood-Group System↗
PubMedDate not supplied

Synthesis and characteristics of allylic 4-pregnene-3,20-diols found in gonadal and breast tissues.

Recently several allylic steroids have been found in gonadal and breast tissues. In order to establish their presence and identity in tissues and determine the possible biological properties, a method for the synthesis of 4-pregnene-3 alpha,20 alpha-diol, 4-pregnene-3 alpha, 20 beta-diol, 4-pregnene-3 beta,20 alpha-diol, and 4-pregnene-3 beta,20 beta-diol was developed using 4-pregnene-3,20-dione (progesterone) as substrate and freshly-prepared aluminum isopropoxide in isopropyl alcohol as reducing agent. The yields were about 19%, 30%, 13%, and 38% for the 3 alpha,20 alpha-, 3 alpha,20 beta-, 3 beta,20 alpha-, and 3 beta,20 beta-diols, respectively. The structures and stereochemistry of these diols were established using proton and carbon NMR spectroscopy and infrared and mass spectrometry.

Chemical Phenomena↗