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S Gupta

Publications and source records attributed to S Gupta.

At least 19 recordsLinked to original sources
PubMed1992

Signal transduction within the nucleus by mitogen-activated protein kinase.

The nucleus is an important target of signal transduction by growth factor receptors that stimulate mitogen-activated protein (MAP) kinases. We tested the hypothesis that MAP kinases have a signaling role within the nucleus by examining the effect of the expression of a human MAP kinase isoform (p41mapk) in tissue culture cells. The expressed p41mapk was found to be localized in both the cytoplasmic and nuclear compartments of the cells. Significantly, the expression of p41mapk caused an increase in the phosphorylation of a nuclear substrate: Ser62 of c-Myc. Phosphorylation at Ser62 stimulated the activity of the NH2-terminal transactivation domain of c-Myc. Thus, p41mapk causes the phosphorylation and regulation of a physiologically significant nuclear target of signal transduction. These data establish that at least one MAP kinase isoform has a nuclear role during signal transduction.

Amino Acid Sequence↗
PubMed1992

Abnormal chloride conductance in multidrug resistant HL60/AR cells.

Chloride channel currents were measured in drug sensitive parental HL60 and multidrug resistant (MDR) subline HL60/AR cells, using a whole cell patch-clamp technique. In addition, the in vitro effects of 4,4' diisothiocyanatostilbene-2,2'-disulfonic acid (DIDS), a Cl- channel blocker, on intracellular accumulation and sensitivity to daunorubicin and intracellular pH (pH(i)) in HL60 cells were examined. Baseline DIDS blockable Cl- currents were consistently lower in HL60/AR cells (0.9 pA/pF) as compared to HL60 cells (7.0 pA/pF). Similarly cAMP-activated Cl- currents were minimal in HL60/AR cells (0.2 pA/pF) as compared to HL60 cells (8 pA/pF). In vitro treatment of drug sensitive HL60 cells with DIDS resulted in concentration-dependent decreased accumulation and increased resistance to daunorubicin and decreased pH(i). These data show that altered Cl- permeability is associated with MDR and suggest that Cl- channels may play a role in MDR.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1992

Protein kinase C isoforms in multidrug resistant P388/ADR cells: a possible role in daunorubicin transport.

To identify the role of protein kinase C (PKC) isoforms in multidrug resistance in tumor cells, we examined the PKC isoform pattern in the multidrug resistant P388/ADR cell line and studied the effect of down regulation of PKC isoforms on intracellular daunorubicin accumulation and P-glycoprotein expression. Using monoclonal antibodies to PKC alpha, beta and gamma and flow cytometry technique we showed that P388/ADR cells overexpressed PKC alpha and beta as compared to drug sensitive P388 cells. Prolonged treatment of P388/ADR cells with phorbol myristate acetate (PMA), a procedure that is known to down regulate PKC, resulted in the down regulation of total PKC activity and the PKC beta isoform (at the protein level) that was accompanied by the correction of daunorubicin accumulation in P388/ADR cells. The level of expression of P-glycoprotein in PMA treated cells was similar to that of untreated cells. These results suggest that PKC beta regulates the drug efflux function of P-glycoprotein.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1992

Effect of cereal-legume chapati diets on absorption and retention of calcium.

Wheat chapati, wheat + Bengal gram (80:20 and 70:30) chapatis and casein diets, at 10 percent protein level, were fed to rats for 12 weeks to study the effect on calcium utilization. The supplementation of Bengal gram to wheat diets significantly improved the calcium absorption. The urinary calcium excretion in wheat + Bengal gram chapati diets was significantly less than that of wheat chapati diet fed group. The in vivo 45Ca absorption (CPM/100 microliters serum) was also less in wheat chapati group as compared to wheat + Bengal gram chapati diets fed groups. The supplementation of legumes to cereals improved the calcium utilization and it may be concluded that there will be no risk of occurrence of protein induced hypercalciuria.

Absorption↗
PubMed1992

Host resistance assays as predictive models in styrene immunomodulation.

Three infection models namely an oncogenic virus Encephalomyocarditis (EMCV), a rodent strain of malaria, Plasmodium berghei, and a rodent hookworm parasite, Nippostrongylus brasiliensis, were used to confirm the in vivo immunotoxic potential of styrene reported in our previous communication. The altered host resistance to these challenge infections was evaluated in rodents pre-treated with 0, 0.02, 0.03 or 0.05 x LD50 dose of styrene (5 days/week) for 4 weeks. Significantly increased mortality in mice was observed at the various tested dose levels of styrene when challenged with EMCV. Similarly the results obtained in the malaria infection model indicated increased blood parasitaemia as well as significantly enhanced mortality in styrene-treated animals. Also the rejection of N. brasiliensis was also found to be significantly impaired in animals treated with a higher dose of styrene. These results indicate that the exposure of rodents to styrene can markedly impair host resistance which may have biological significance.

Adjuvants, Immunologic↗
PubMed1992

Epidermoid cyst in association with subcutaneous meningioma.

A 17-year-old female presented with a non-tender, firm and fixed swelling in the right frontal region. Skull x-rays revealed soft tissue shadow and mild hyperostosis of the underlying frontal bone. Histopathological examination after excision showed it to be a meningioma with an epidermoid cyst.

Adolescent↗
PubMed1992

Endothelium-dependent inhibition of Na(+)-K+ ATPase activity in rabbit aorta by hyperglycemia. Possible role of endothelium-derived nitric oxide.

Hyperglycemia has been shown to diminish Na(+)-K+ ATPase activity in rabbit aorta. To examine the basis for this effect, aortic rings were incubated for 3 h in Krebs-Henseleit solution containing 5.5 or 44 mM glucose, and Na(+)-K+ ATPase activity was then quantified on the basis of ouabain-sensitive (OS) 86Rb-uptake. Incubation with 44 mM glucose medium caused a 60% decrease in Na(+)-K+ ATPase activity in rings with intact endothelium (from 0.22 +/- 0.01 to 0.091 +/- 0.006 nmol/min per mg dry wt; P less than 0.01). Similar decreases (45%; P less than 0.01) in Na(+)-K+ ATPase activity were seen when rings incubated with 5.5 mM glucose were exposed to NG-monomethyl L-arginine (300 microM), an inhibitor of endothelium-derived nitric oxide (EDNO) synthesis or when the endothelium was removed (43% decrease). The decrease in Na(+)-K+ ATPase activity induced by hyperglycemia was totally reversed upon adding to the medium either L-arginine, a precursor of EDNO biosynthesis or sodium nitroprusside, which bypasses endothelium and directly activates the soluble guanylate cyclase in vascular smooth muscle. A decrease in Na(+)-K+ ATPase activity (42%; P less than 0.05), only seen in the presence of endothelium, was also observed in aortas taken directly from alloxan-induced diabetic rabbits. These studies suggest that the decrease in vascular Na(+)-K+ ATPase activity induced by hyperglycemia is related, at least in part, to a decrease in the basal release of EDNO. They also suggest that alterations in basal EDNO release and possibly Na(+)-K+ ATPase activity contribute to the impairment in vascular relaxation caused by hyperglycemia and diabetes.

Animals↗
PubMed1992

Phase I-II study of high-dose epirubicin in advanced non-small-cell lung cancer.

PURPOSE: A phase I multicenter trial was performed to determine the maximum-tolerated dose (MTD) of epirubicin, given on 3 consecutive days every 3 weeks to previously untreated patients with advanced non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: After appropriate staging and a baseline multiple-gated angiogram (MUGA) scan, at least four patients were entered at each dose level, starting at 35 mg/m2 of epirubicin given intravenously (IV) daily for 3 days (105 mg/m2) and escalating by 5 mg/m2 per injection in each dose level (15 mg/m2 per course). Epirubicin was administered up to a maximum dose of 60 mg/m2/d for 3 days (180 mg/m2). The MTD was determined to be 55 mg/m2/d for 3 days (165 mg/m2) after treating a total of 35 (33 assessable) patients. Nadir granulocyte counts and associated febrile episodes comprised the dose-limiting toxicity, but there were no treatment-related deaths. A phase II trial was performed using a dose of 50 mg/m2/d for 3 days (150 mg/m2) every 3 weeks with no dose escalation, but with dose reduction for toxicity as required. A total of 30 patients were entered onto this phase of the study. RESULTS: The major toxicity, as in the phase I trial, was neutropenia with five febrile episodes, again with no treatment-related deaths. An overall response rate of 12 of 63 (19%) was noted in the combined patient population of the phase I-II trial, with 95% confidence intervals of 10% to 31%. When the response rate was analyzed by histology, only one of 17 (6%) patients with squamous histology, as compared with 11 of 46 (24%) with non-squamous histology, responded, but this did not reach statistical significance (P = .15). CONCLUSIONS: High-dose epirubicin is tolerable and is an active single agent in NSCLC. It should be combined with relatively nonmyelosuppressive agents such as cisplatin to try to obtain higher response rates and extend the survival in this disease.

Adult↗
PubMed1992

Interrelationship between ovine follicular fluid inhibin and serum albumin.

Ovine follicular fluid inhibin (oFF-I) as isolated in this laboratory, proved to be a monomeric protein (M(r).65 kDa). It was found to share very many of the physico-chemical characteristics of ovine serum albumin (oSA)-such as molecular size, iso-electric point, N-terminal aminoacid, finger-print patterns following enzymatic or cyanogen bromide cleavage, as well as binding of estradiol-17 beta and tryptophan. Furthermore, an antiserum containing polyclonal antibodies to oSA showed perfect cross-reaction with oFF-I. Nevertheless, oFF-I is distinct and different from oSA, as would be evident from the data reported here. Of the two proteins, oFF-I alone is capable of suppressing pituitary FSH output in a dose-dependent manner. Secondly, an antiserum containing polyclonal antibodies against Fraction-S2, a partially purified, biologically active fragment (M(r): 30-40 kDa)-derived from oFF-I, cross-reacted with the 65 kDa inhibin, but did not recognize oSA. Finally, the CD-spectra of the two proteins, when examined as a function of pH, show characteristic differences.

Animals↗
PubMed1992

Changing profile of enteric fever--in summer-91.

The clinical presentation, complications and sensitivity pattern was studied in 30 cases of enteric fever. Fever was the main presenting feature in all. Other associated predominant presenting feature were vomiting in 15 (50%), Loose motion 9 (30%), Cough 6 (20%), headache 4 (13.33%) and altered sensorium in 2 (6.66%). The various complications observed during hospital stay were myocarditis 5 (6.16%), Paralytic ileus 2 (6.66%), Pneumonia 1 (3.33%) and Joint effusion in 2 (6.66%) cases respectively. In laboratory parameters-mild elevation of blood urea and SGOT/SGPT were detected in 1st week, which returned to normal in 2-3 weeks time. In vitro sensitivity of organism isolated (24 cases) were as follow--Chloramphenicol 7 (29.16%), Ampicillin 8 (33.33%), Gentamicin 22 (91.66%), Amikacin 24 (100%), Cefotaxime 22 (91.66%), Ciprofloxacin 24 (100%), and Ofloxacin 24 (100%). Clinical response to Ofloxacin and Ciprofloxacin was 100%, and fever subsided in 3-5 days.

Adolescent↗
PubMed1992

Rabies vaccine.

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Humans↗