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Biomedical subjects

S Gupta

Publications and source records attributed to S Gupta.

At least 1,063 records · Page 59Linked to original sources
PubMed1993

Chlamydial cervicitis: role of culture, enzyme immunoassay and Giemsa cytology in diagnosis.

Three different laboratory tests were carried out to find the occurrence of chlamydial infections in a selected group of 150 female patients presenting clinically with cervicitis. The tests included isolation using a cell culture system, enzyme immunoassay (EIA) for antigen detection and Giemsa cytology of endocervical smears. Contrary to earlier reports on cytological diagnosis of chlamydial cervicitis, endocervical smears stained by Giemsa stain and EIA for antigen detection were found to be of comparable sensitivity and specificity (73.1% and 86.3% for smear, and 76.1% and 90.9% for EIA, respectively) when cell culture was used as the gold standard.

Animals↗
PubMed1993

Cell cycle regulation of the c-Myc transcriptional activation domain.

The product of the c-myc gene (c-Myc) is a sequence-specific DNA-binding protein that has previously been demonstrated to be required for cell cycle progression. Here we report that the c-Myc DNA binding site confers cell cycle regulation to a reporter gene in Chinese hamster ovary cells. The observed transactivation was biphasic with a small increase in G1 and a marked increase during the S-to-G2/M transition of the cell cycle. This cell cycle regulation of transactivation potential is accounted for, in part, by regulatory phosphorylation of the c-Myc transactivation domain. Together, these data demonstrate that c-Myc may have an important role in the progression of cells through both the G1 and G2 phases of the cell cycle.

Animals↗
PubMed1993

Differential effect of metabolic fuels on the energy state and Na(+)-K(+)-ATPase in isolated cerebral microvessels.

Isolated bovine cerebral microvessels (ICMV) were incubated with different metabolic fuels to determine their ability to support microvessel Na(+)-K(+)-ATPase (quantitated as ouabain-sensitive 86Rb+ uptake) and the ATP/ADP ratio. In comparison with ICMV incubated with glucose, Na(+)-K(+)-ATPase activity was reduced by 55% after a 3-h incubation in fuel-free medium and by 30-40% after incubation with beta-hydroxybutyrate, acetoacetate, or glutamate. However, Na(+)-K(+)-ATPase activity was not significantly decreased in ICMV incubated with pyruvate or oleate plus carnitine. In contrast, only glucose was able to maintain the ATP/ADP ratio. To evaluate the effect of endogenous fatty acid metabolism on these parameters, ICMV were incubated with bromostearate, an inhibitor of fatty acid oxidation. Bromostearate decreased both Na(+)-K(+)-ATPase activity and the ATP/ADP ratio, even in the presence of glucose. These results indicate that the varying effects of different fuels on Na(+)-K(+)-ATPase in ICMV cannot be explained solely by their effects on the ATP/ADP ratio or on glycolytic ATP generation. They suggest that other fuel-modulated factors play a key role in regulating this enzyme.

3-Hydroxybutyric Acid↗
PubMed1993

Reduced Na(+)-K+ pump activity in diabetic rabbit carotid artery: reversal by aldose reductase inhibition.

This study addresses the question of whether a decrease in basal Na+ pump [Na(+)-K(+)-adenosinetriphosphatase (ATPase)] activity occurs in the carotid artery of an alloxan-diabetic rabbit and, if so, whether it is associated with altered 86Rb+ uptake and contractile response to ouabain and K(+)-free solution. Ouabain-sensitive 86Rb+ uptake, an index of Na+ pump activity, was diminished approximately 50% in carotid arteries from diabetic rabbits. Concurrent with this, contractions induced by incubating the carotid arteries in a K(+)-free solution (in the absence of phentolamine) were significantly larger in the diabetic group. Readdition of K+ (1 mM) to arteries contracted with the K(+)-free solution caused relaxations that were slower to occur and of lesser magnitude in diabetic than in control rabbits. In contrast to the contractions caused by the K(+)-free medium, contractions caused by incubation with ouabain (1 mM) in the presence of phentolamine were significantly smaller in the diabetic group. Treatment of diabetic rabbits with an aldose reductase inhibitor, zopolrestat, at both high and low doses restored the alterations in vascular reactivity toward normal. The results indicate that the Na+ pump activity is diminished in the carotid artery of diabetic rabbit, and this is associated with abnormal vascular responsiveness and increased polyol pathway flux.

Aldehyde Reductase↗
PubMed1993

Influence of size of liposomes in potentiating the efficacy of encapsulated triethylenetetramine-hexaacetic acid (TTHA) against cadmium intoxication.

Polyaminocarboxylic acids have widely been used an antidotes in heavy metal intoxication, however their hydrophilic nature renders them to be mostly distributed extracellularly. To facilitate the intracellular delivery of such chelating agent, triethlenetetraamine-hexaacetic acid (TTHA) was encapsulated in small unilamellar vesicles (SUV) or dehydration rehydration vesicles (DRV) and its effect was examined in the amelioration of cadmium toxicity. Mice were administered cadmium (0.2 mg/kg B.wt.) as CdCl2 intraperitoneally daily for five days. After a period of four weeks rest. they were given two intravenous injections of TTHA as free material or encapsulated in liposomes (0.16 m mole/kg) at a gap of 48 hours. Urinary and fecal elimination of cadmium and its distribution in the liver, kidney and spleen was monitored after TTHA treatment. The results indicate the efficacy of TTHA in removing cadmium from the body organs of preexposed animals and its excretion through urine and feces was maximum when it was encapsulated in SUV liposomes.

Animals↗
PubMed1993

Post-penetrating keratoplasty glaucoma.

To study the risk factors in the development of glaucoma following penetrating keratoplasty, we retrospectively analysed 190 eyes of 185 consecutive patients who had undergone surgery during 1990. The donor button was larger by 0.2 mm and 0.5 mm in phakia and aphakia/pseudophakia patients, respectively. Over a mean follow-up period of 14.5 months, 52 of the 190 eyes (27.4%) either developed glaucoma de novo or had worsening of preexisting glaucoma. Of these 52 eyes, 38 were managed medically and 14 required surgery. From our study, aphakia (37%), pseudophakia (24%), preexisting glaucoma (81.8%), and regrafting (43.18%) were found to be the significant risk factors in the development of glaucoma following penetrating keratoplasty.

Aphakia, Postcataract↗