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Biomedical subjects

R Gupta

Publications and source records attributed to R Gupta.

At least 379 records · Page 21Linked to original sources
PubMed1998

An investigation of the mechanism of flux across polydimethylsiloxane membranes by use of quantitative structure-permeability relationships.

Quantitative structure-permeability relationships (QSPRs) based on readily calculated parameters have been developed to study penetration across a polydimethylsiloxane membrane. Maximum steady-state flux values for 256 compounds through a polydimethylsiloxane membrane were taken from previous studies. Forty-three physicochemical parameters were calculated for each compound and their significance to flux determined. Removal of fourteen outliers enabled derivation of a significant three-parameter QSPR based on the number of hydrogen-bond acceptor and donor groups and sixth-order path molecular connectivity. Models based on parameters important for penetration across human skin (log P and molecular weight) were comparatively poor. This model suggests that the mechanism of flux across a polydimethylsiloxane membrane is based mainly on hydrogen-bonding effects; as such it occurs via a mechanism of action different from that of penetration of the skin in man.

Administration, Cutaneous↗
PubMed1998

Oral zinc therapy in diabetic neuropathy.

The present double blind randomized study was conducted on 50 subjects; 20 age and sex matched healthy controls (Group--I); 15 patients of diabetes mellitus with neuropathy who received placebo for 6 weeks (Group--IIA); and 15 patients of diabetes mellitus with neuropathy who were given supplemental zinc sulphate (660 mg) for 6 weeks (Group--IIB). Serum zinc level, fasting blood sugar (FBS) and post prandial blood sugar (PPBS) levels and motor nerve conduction velocity (MNCV) were estimated on day 0 and after 6 weeks in all subjects. Serum zinc levels were significantly low (p < 0.001) in group IIA and IIB as compared to healthy controls (Group--I) at baseline. After 6 weeks the change in pre and post therapy values of FBS, PPBS and MNCV (median and common peroneal nerve) were highly significant (P = < 0.001) for group IIB alone with insignificant change (P = > 0.05) in group IIA. No improvement (P = > 0.05) in autonomic dysfunction was observed in either groups. Therefore, oral zinc supplementation helps in achieving better glycemic control and improvement in severity of peripheral neuropathy as assessed by MNCV.

Administration, Oral↗
PubMed1998

Educational status and dietary fat and anti-oxidant intake in urban subjects.

To assess correlation of dietary atherogenic and anti-atherogenic factors with socio-economic status (SES) we performed nutritional survey among 182 (122 men, 60 women) randomly selected individuals using 24 hour diet recall and a food-frequency questionnaire. SES was assessed by educational level which strongly correlated with occupational class (r = 0.55) and income levels (r = 0.88). There was significant (p < 0.05) positive correlation (r values) of educational level with intake of calories (0.55), proteins (0.19), fat (0.45), fat derived energy (en%) (0.14), saturated fat en% (0.45), linoleic acid (0.17), vitamin A (0.14), vitamin C (0.16), vitamin E (0.44), fruits and vegetables (0.34) and fibre (0.24) and negative correlation with intake of linolenic acid (-0.35), monounsaturated fat (MUFA) en% (-0.15), polyunsaturated fat (PUFA)/saturated fat (SFA) (-0.33) and MUFA/SFA (-0.42). In persons of highest educational level (> 15 years education) vs illiterates, the daily intake of SFA (29.1 +/- 15 vs 7.8 +/- 6), SFA en% (13.2 +/- 5 vs 6.7 +/- 4), linoleic acid en% (5.4 +/- 3 vs 3.9 +/- 2) and n6/n3 (24.0 +/- 58 vs 4.5 +/- 5) was more and intake of linolenic acid en% (0.7 +/- 1 vs 1.6 +/- 1), MUFA en% (8.6 +/- 7 vs 15.6 +/- 9), PUFA/SFA (0.6 +/- 1 vs 1.0 +/- 1) and MUFA/SFA (0.7 +/- 1 vs 4.0 +/- 5) was less. Intake of antioxidant vitamins A, C and E and fruits and vegetables was significantly more in better educated.

Adult↗
PubMed1998

Antioxidant phenolics and flavonoids in common Indian foods.

To determine antioxidant phenolics and flavonoids in commonly consumed Indian foods we chemically analysed 85 food-stuffs comprising of cereals, pulses, nuts, oilseeds, vegetables, fruits and beverages. Total phenolics were measured biochemically and flavonoids were measured as a sum of quercetin, kaempferol, luteolin and pelargonidin. High flavonoid content (> 100 mg/100 gm) was present in tea, coffee, apple, guava, terminalia bark, fenugreek seeds, mustard seeds, cinnamon, red chili powder, cloves and turmeric. Medium levels (50-100 mg) were found in Indian gooseberry, omum, cumin, cardamom, betel leaf and brandy. Small but significant amounts were also present in food-items of large consumption such as kidney beans, soyabeans, grapes, ginger, coriander powder, bajra and brinjal.

Antioxidants↗
PubMed1998

Renal cell carcinoma metastatic to the contralateral ureter.

The ureter is an uncommon location for cancer metastases, the majority of which are due to nonurologic cancers such as stomach and breast.(1) Renal cell carcinoma (RCC) metastatic to the ureter has been reported infrequently. We report a case of metachronous metastatic RCC to the contralateral ureter.

Journal Article↗
PubMed1998

Biochemical pathway mediating the response of bone cells to capacitive coupling.

Rat calvarial bone cells or mouse MC3T3-E1 bone cells subjected to a capacitively coupled electric field of 20 mV/cm consistently showed significant increases in cellular proliferation as determined by deoxyribonucleic acid content. Verapamil, a membrane calcium channel blocker; W-7, a calmodulin antagonist; indocin, a prostaglandin synthesis inhibitor; or bromophenacyl bromide, a phospholipase A2 inhibitor, each at a concentration that did not interfere with cell proliferation in control cultures, inhibited proliferation in those cultures subjected to the electric field. In contrast, neomycin, an inhibitor of the inositol phosphate cascade, did not inhibit this electrically induced cellular proliferation. Prostaglandin E2 production also was increased significantly with electrical stimulation, and this increase was inhibited by verapamil or indocin but not by neomycin. Thus, the data suggest that the signal transduction mediating the proliferative response of cultured bone cells to a capacitively coupled field involved transmembrane calcium translocation via voltage gated calcium channels, activation of phospholipase A2, and a subsequent increase in prostaglandin E2. Increases in cytosolic calcium and activated calmodulin are implied. The inositol phosphate pathway, unlike its dominant role in signal transduction in mechanically stimulated bone cells, does not appear to play a role in signal transduction in the proliferative response of bone cells to electrical stimulation.

Animals↗
PubMed1998

Purification and characterization of a regiospecific lipase from Aspergillus terreus.

Aspergillus terreus lipase was purified to homogeneity with 18.0% yield. The specific activity of the enzyme increased from 20.80 to 250 U/mg of protein. Ion exchange on Q-Sepharose was highly effective in the purification process. The molecular mass of the purified enzyme was 41+/-1 kDa as determined by SDS/PAGE. The purified lipase showed excellent temperature tolerance (15-90 degreesC) and was highly thermostable, retaining 100% activity at 60 degreesC for 24 h. It showed good pH tolerance (3.0-12.0) and was stable over a pH range of 4.0-10.0 for 24 h. The activity of the enzyme was inhibited by ionic detergents, whereas non-ionic detergents stimulated enzyme activity. Mg2+ and Ca2+ ions stimulated lipase activity, whereas Co2+, Cu2+, Ni2+ and Fe3+ ions caused inhibition. The enzyme was unaffected by the metal chelator EDTA or by 2-mercaptoethanol and potassium ferrocyanide. At a concentration of 100 microM, 3,4-dichloroisocoumarin caused weak inhibition with 40% loss of activity, but diethyl p-nitrophenyl phosphate at the same concentration strongly inhibited enzyme activity (98.12% loss of activity), confirming that the A. terreus lipase is a serine hydrolase. The lipase was highly active on pig fat (151% relative activity) and groundnut oil (103% relative activity) and least active on kusum oil (18% relative activity). Extensive dialysis did not affect enzyme activity up to 168 h, suggesting the absence of any dialysable cofactor in the enzyme. The A. terreus lipase retained significant activity on freeze-drying and had a shelf-life of more than 6 months at room temperature. The A. terreus lipase exhibited 1,3-regiospecificity and was stable in various organic solvents.

Aspergillus↗
PubMed1998

Incidence of dengue fever in relation to climatic factors in Ludhiana, Punjab.

An outbreak of dengue fever occurred in Ludhiana in 1996 and 1997. A total of 505 patients who attended the hospital attached to Dayanand Medical College, Ludhiana were clinically diagnosed to have dengue fever. Of these, 460 cases were noticed between October and December 1996 while during 1997 only 45 dengue fever cases were observed. Serological examination using dengue IgG and IgM blot was performed with single serum samples of 189 patients. Of these, 129 serum samples were detected positive for anti dengue antibodies. Twenty eight patients died in the dengue epidemic, 12 of whom suffered from dengue haemorrhagic fever (DHF) and six with dengue shock syndrome (DSS). Male patients outnumbered the female patients. Seasonal and cyclic pattern of the disease incidence was observed.

Adolescent↗
PubMed1998

Leishmaniasis in the United States military.

Leishmaniasis is a recurrent health problem for the U.S. and other militaries. Health care workers may be unfamiliar with the risk factors, transmission, clinical features, diagnosis, and treatment of this disease. A team of highly trained specialists is required to properly manage service members with leishmaniasis. Such care is available only in a few medical centers. Although there are no prophylactic drugs to prevent this disease, control of insect populations and use of personal protection measures can minimize arthropod-related casualties. The impact of leishmaniasis on military operations and research initiatives to better prevent, diagnose, and treat infection are discussed.

Humans↗
PubMed1997

Recombination activities of HsDmc1 protein, the meiotic human homolog of RecA protein.

Meiosis-specific homologs of RecA protein have been identified in Saccharomyces cerevisiae and higher eukaryotes including mammals, but their enzymatic activities have not been described. We have purified the human protein HsDmc1 produced in Escherichia coli from a cloned copy of the cDNA. The recombinant enzyme had DNA-dependent ATPase activity with an estimated kcat of 1.5 min-1. DNase protection experiments with oligonucleotides as substrates indicated that HsDmc1 protein binds preferentially to single-stranded DNA with a stoichiometry of approximately one molecule of protein per three nucleotide residues. HsDmc1 protein catalyzed the formation of D-loops in superhelical DNA, as well as strand exchange between single-stranded and double-stranded oligonucleotides. The requirements for strand exchange catalyzed by HsDmc1 were similar to those of RecA protein, but exchange caused by HsDmc1 was not supported by ATPgammaS.

Adenosine Triphosphatases↗