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Biomedical subjects

R Sharma

Publications and source records attributed to R Sharma.

At least 559 records · Page 31Linked to original sources

Response of psychotic and nonpsychotic depression to phenelzine.

The authors studied 52 depressed inpatients to examine treatment response to phenelzine, a monoamine oxidase (MAO) inhibitor. All patients were classified into one of three RDC categories (definitely psychotic, probably psychotic, and nonpsychotic). For the entire sample, the mean platelet MAO inhibition level achieved with phenelzine was greater than 80%. Response to treatment was determined by independent clinical assessment and by the change in rating scores from baseline; 68% of the nonpsychotic, 43% of the probably psychotic, and 21% of the definitely psychotic patients were classified as responders. This differential response rate is similar to that reported in the literature for tricyclic antidepressants.

Antidepressive Agents, Tricyclic↗

Ipsilateral progressive hydrocephalus due to acquired foramen of Monro obstruction: an unusual complication of brain abscess in cyanotic heart disease. A case report.

An unusual complication of brain abscess in cyanotic heart disease is presented. This patient, who was suffering from recurring brain abscesses at different sites was diagnosed on regular follow-up, and a metrizamide computed tomographic ventriculogram confirmed the diagnosis of foramen of Monro obstruction ipsilateral to the abscess.

Brain Abscess↗

A comparison of thiothixene with chlorpromazine in the treatment of mania.

High potency neuroleptics have been advocated for acute mania because their side effect profile may allow for a more rapid dose escalation and symptom resolution. Low potency neuroleptics have also been advocated because their sedative properties might better calm the acutely agitated manic patient. The authors tested these hypotheses using a double-blind design comparing thiothixene with chlorpromazine in 29 manic patients on a standard dose of lithium. They found that thiothixene and chlorpromazine produced identical rates and degree of improvement, that side effect profiles differed for each drug but did not affect overall clinical response, and that most patients had a good response on much lower than expected doses. The implications for less aggressive use of neuroleptics to treat mania are discussed.

Adult↗

Age-dependent activation of glucocorticoid receptors in the cerebral hemispheres of male rats.

The binding of [3H]dexamethasone-receptor complexes to purified nuclei was studied in the cerebral hemispheres of immature (3-week-old) and mature (26-week-old) Long-Evans male rats to determine the age-related changes, if any, in the physicochemical properties of glucocorticoid receptors. Our data show that heat activation (for 45 min at 25 degrees C) significantly enhances the nuclear binding of [3H]dexamethasone-receptor complexes in rats of both ages, with a greater magnitude in immature rats. Ca2+ activation (20 mM Ca2+ for 45 min at 0 degree C) also enhances the nuclear binding of bound receptor complexes but to a similar extent at both ages. These findings indicate that some of the physicochemical properties (e.g. heat activation) of glucocorticoid receptor change, while others (e.g. Ca2+ activation) remain unchanged at different phases of the lifespan.

Aging↗

Age-dependent regulation of glucocorticoid receptors in the liver of male rats.

Specific binding of [3H]dexamethasone to cytosol and the activation of bound hormone-receptor complexes were studied in the liver of immature (3 weeks old) and mature (26 weeks old) Long-Evans male rats. The concentration of specific binding sites was significantly higher (33%) in the liver of immature rats as compared to mature, while dissociation constants (Kd) remain unaltered at both ages. Heat activation (for 45 min at 25 degrees C) significantly enhances the binding of [3H]dexamethasone-receptor complexes to DNA-cellulose and purified nuclei at both the ages, with a greater magnitude in mature rats. Cross mixing experiments (i.e., binding of activated cytosol from mature rats to nuclei of immature and vice-versa) show receptor specificity. Ca2+ activation (20 mM Ca2+ for 45 min at 0 degree C) also enhances the nuclear and DNA-cellulose binding at both the ages, but to a similar extent. Differences in the number of specific binding sites and some of the physiochemical properties of glucocorticoid receptors presented here between immature and mature rats may underlie the functional changes in tissue response with age.

Age Factors↗

Effect of the mi allele on mast cells, basophils, natural killer cells, and osteoclasts in C57Bl/6J mice.

The osteopetrotic, microphthalmic (mi/mi) mouse lacks functional osteoclasts and has also been reported to be deficient in mast cells and natural-killer (NK) cells. The later deficiencies could be secondary to the osteopetrotic marrow, or a direct result of the mi allele. Therefore, heterozygotes were examined for these cell types, since these mice do not exhibit osteopetrosis. Adult +/mi animals have approximately 50%, and mi/mi animals examined by histologic techniques or tissue histamine levels have 0-10%, of the peritoneal, dermal, and intestinal mast cells compared with that of +/+ animals. Leukocyte histamine, indicative of the number of basophils, demonstrates the same pattern. Histamine content per mast cell in +/+ and +/mi animals is identical. The number of large granular lymphocytes (LGL) in splenic leukocyte preparations from +/mi animals is 50% that of +/+ animals, and these cells are undetectable in preparations from mi/mi mice. NK activity against YAC-1 cells paralleled the number of LGL present. The resorptive response of neonatal calvaria to parathyroid hormone was delayed in the case of cultured +/mi bone compared with that of +/+ bone, but the final rate of calcium release was identical. These data indicate that 1) the presence of one mi allele can affect the development of four distinct cell types, and 2) osteopetrosis alone does not account for the lack of mast cells, basophils, and NK cells in mi/mi mice.

Alleles↗

Regulation of aspartate aminotransferase isoenzymes by hydrocortisone in the liver of aging rats.

The activities and induction patterns of the isoenzymes of aspartate aminotransferase of the liver of male rats of various ages were studied. The activity of cytoplasmic aspartate aminotransferase increases gradually till adulthood and remains constant thereafter with increasing age of the rat. However, the activity of mitochondrial isoenzyme remains constant throughout the life span of the rat. Adrenalectomy decreases and hydrocortisone increases the activity of cytoplasmic isoenzyme in rats of all ages. In contrast, the above treatments do not shown any affect on the activity of mitochondrial isoenzyme in the liver of rats of all ages.

Adrenalectomy↗

Differential effects of hydrocortisone on aspartate aminotransferase isoenzymes of the liver of rats during growth, development, and senescence.

The activity and induction patterns of the isoenzymes of aspartate aminotransferase (AsAT) of the liver of male rats during growth, development, and senescence were studied. The activity of both the cytoplasmic and mitochondrial isoenzymes increased significantly until adulthood and remained constant thereafter. Adrenalectomy decreased, and hydrocortisone administration increased, the activity of the cytoplasmic AsAT of the liver of young-immature, adult, and senescent rats. However, the degree of these responses decreased with increasing age of the animal. The hormone-mediated induction of this isoenzyme is actinomycin D-sensitive. Mitochondrial AsAT on the other hand is irresponsive towards these treatments throughout the life span of the rat.

Animals↗