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Biomedical subjects

S K Sharma

Publications and source records attributed to S K Sharma.

At least 397 records · Page 22Linked to original sources
PubMed1991

Effect of prednisolone treatment in chronic silicosis.

We evaluated the effects of daily oral prednisolone therapy on alveolitis parameters and pulmonary function tests over a 6-month period in patients with chronic silicosis. Pulmonary function tests were done in 34 patients, and bronchoalveolar lavage (BAL) was done in 21 of them. Pulmonary function tests showed a significant improvement in lung volumes, FEV1, PEFR, SGaw, DLCO, and PaO2. Analysis of BAL fluid revealed a significant decrease in total cell count. Mean fibronectin and immunoglobulin values in BAL fluid also were lower after treatment, but the change was not statistically significant. No serious side effects were encountered with prednisolone therapy. These results indicate that daily oral prednisolone therapy may suppress the alveolitis in certain patients with chronic silicosis and bring about a significant improvement in lung functions and gas exchange.

Adult↗
PubMed1991

Tissue dose estimates following the selective uptake of 125IUdR and other radiolabelled thymidine precursors in resistant tumours.

For the purposes of evaluation of the therapeutic potential of the radiohalogenated thymidine analogue 125IUdR, estimation of the radiation dose to the tumour cells and normal tissues is important. To determine the dose to any tissue from the radionuclide 125I is not simple, since the major emissions are very short-range Auger electrons. The cytotoxicity of 125I is strongly dependent on the position of the decay relative to the DNA, the principal target for cell sterilization. Estimates of the cytotoxicity of 125I based on the traditional MIRD recommended formulation (ICRU Report 32, 1979) may produce gross underestimates if it is incorporated into the DNA via the thymidine precursor 125IUdR. In this work, tissue count and autoradiography (ARG) data from studies by Bagshawe et al were used to estimate tissue doses following the administration of 125IUdR to LS174/T (a colorectal carcinoma) and CC3 (a choriocarcinoma) tumour-bearing animals, after a hydroxyurea block of the normal tissue turnover. The tumour cell toxicity is estimated from ARG data on the degree of 125I incorporation into the cell nucleus. Major drawbacks with 125I for this type of therapy are the long 60-day half-life, leading to radiological and waste disposal problems and the extreme short range of the radiotoxic effects. Possible alternative radiohalogens, 13I, 77Br, 131I and 211At, are suggested in place of 125I in the thymidine analog iododeoxyuridine. Dose calculations are performed and cytotoxicities estimated on the assumption that their biological retention characteristics are the same as for 125IUdR.

Adenocarcinoma↗
PubMed1991

Bioenvironmental control of malaria at the Indian Drugs and Pharmaceuticals Ltd., Rishikesh (U.P.).

Bioenvironmental control of malaria was achieved at the Indian Drugs and Pharmaceuticals Ltd. (IDPL) complex, Rishikesh, Dehra Dun distt., Uttar Pradesh, India. The IDPL complex is in 15 sq km area with about 25,000 population. One major mosquito-breeding site of about one sq km was eliminated by diverting the factory effluents into a drain. Filling borrow pits, ditches and low-lying areas with burnt coke ash, cleaning blocked drains, mosquito-proofing the overhead water tanks, application of larvivorous fishes and improved case detection and treatment were the additional malaria-control measures. Impact assessment of the interventions revealed that there was 25% reduction in malaria incidence as well as 90% reduction in the use of antimalarials, and a considerable reduction in nuisance mosquito species and malaria vector densities.

Animals↗
PubMed1991

A survey of six genetic markers on the populations of Punjab and Rajasthan (India).

190 Punjabis (Hindus and Sikhs) of Chandigarh and 152 Hindus of Jodhpur (Rajasthan) were examined for six genetic markers, four of which (APO C-II, C6, C7 and FXIIIA) were not studied before in Asiatic Indians. For APO C-II and C7 only the common phenotype was found in a total of 229 and 99 subjects, respectively. For the remaining four markers the two samples were pooled since the gene frequency estimates were not significantly different: FXIIIA*2 = 0.205 +/- 0.016; C6*B = 0.366 +/- 0.037; PGM1*2 = 0.247 +/- 0.017; PGD*C = 0.041 +/- 0.008. These data may contribute to evaluate the extent of the Mongoloid genetic admixture into the Caucasoid gene pool of the Punjab and Rajasthan Hindu population.

Apolipoprotein C-II↗
PubMed1991

Metal affinity chromatography of recombinant HIV-1 reverse transcriptase containing a human renin cleavable metal binding domain.

A metal binding peptide, hexahistidine, preceding a renin cleavage sequence (Pro-Phe-His-Leu-Val-Ile-His-) was engineered on to the N-terminus of HIV-1 reverse transcriptase (RT). The chimeric protein was expressed in Escherichia coli and characterized after purification by DEAE chromatography and HPLC. Amino-terminal sequencing confirmed the presence of the first 15 amino acids of the chimeric protein. The chimeric exhibited RT activity like that of HIV-1 RT and was cleaved by human renin at the expected site. The potential of a hexa-histidine fusion in the purification of recombinant HIV-1 RT by immobilized metal affinity chromatography (IMAC) on the commonly used resin (IDA-Ni2+) was investigated. The chimeric gene product from a crude E. coli extract was strongly retarded on a immobilized nickel column, while most of the contaminating E. coli proteins were eliminated after elution with 20-35 mM imidazole. The bound chimeric protein was eluted with 300 mM imidazole and appeared predominantly as a single band on an SDS-polyacrylamide gel. The remarkable specificity of this affinity tail was further demonstrated by separating the chimeric protein from HIV-1 RT in a crude extract prepared by mixing extracts from cells expressing HIV-1 RT and the hexahistidine recombinant chimeric protein. The usefulness of a enzymatically cleavable metal binding peptide in the rapid purification and production of HIV-1 RT without proteolysis to a heterodimer is discussed.

Amino Acid Sequence↗
PubMed1991

Iron status in patients of rheumatoid arthritis with special reference to serum ferritin levels.

Thirty patients of rheumatoid arthritis comprising 16 classical and 14 definite cases based on the ARA criteria were evaluated in a prospective and controlled study for iron status with special reference to serum ferritin levels. Serum ferritin levels were estimated by RIA technique and marrow iron status was ascertained by semi-quantitative estimation after Pearl's staining of marrow aspirate (G 0-6). Marrow iron stores were found absent to decreased in 17 patients (56.7%), normal in 2 (6.7%) and increased in 11 patients (36.6%). The serum ferritin levels in the iron depleted rheumatoid arthritis patients were significantly lower in comparison to patients with normal to increased marrow iron stores (23.91 +/- 11.45 ug/L vs 69.94 +/- 24.7 ug/L, p less than 0.001). There was a strong positive correlation between serum ferritin levels and marrow iron stores (r = +0.08, p less than 0.001). A serum ferritin value of less than or equal to 32 ug/L was a good predictor of decreased iron stores in the bone marrow, with a sensitivity of 88.2% and specificity of 84.5%. The test had a predictive value of 83.33%. There was no correlation between marrow iron stores and conventional indicators or iron status i.e. serum iron, TIBC, transferrin saturation and MCHC. It is concluded that serum ferritin correlates well with marrow iron stores and can be used as a simple non-invasive test for predicting iron-deficiency in patients of rheumatoid arthritis.

Adult↗
PubMed1991

Antimicrobial drug use in urology.

Antimicrobial drug utilization patterns were studied on patients in the Urology Ward of Nehru Hospital attached to the Postgraduate Institute of Medical Education and Research, Chandigarh. The study was done over a six-month period in which antimicrobial prescription for all patients admitted under urology services were monitored and followed. There were 57 cases of benign hypertrophy of the prostate, 40 of urinary calculi and 20 each of congenital malformation, malignancies, strictures and other conditions. Gentamycin and cotrimoxazole were the most frequently used antimicrobials, as calculated by the DDD/100 bed days.

Adult↗
PubMed1990

Alterations in brainstem alpha 2 adrenoreceptor activity in pyridoxine-deficient rat model of hypertension.

Moderate pyridoxine deficiency in adult male Sprague-Dawley rats results in significant hypertension, associated with a general sympathetic stimulation, including an increase in the turnover of norepinephrine in the heart. Treatment of these rats with pyridoxine reversed blood pressure to normal within 24 h. Treatment of pyridoxine-deficient rats with clonidine or alpha-methyl dihydroxyphenylalanine (alpha-methyl DOPA) also reduced the blood pressure of these animals to normal. There was also a significant increase in the Bmax of high and low affinity [3H]p-amino-clonidine binding to crude synaptosomal membrane preparations of the brain stem of deficient rats indicating chronic underexposure of alpha 2 adrenoreceptors to endogenous norepinephrine.

Animals↗
PubMed1990

Influence of B vitamins on binding properties of serotonin receptors in the CNS of rats.

Treatment of normal adult rats with pyridoxine or a B-vitamin mixture resembling Neurobion led to an increase in serotonin content of various brain areas and to a decrease in the number of serotonin S2 receptors. The results indicate that the pyridoxal phosphate level in regions of the brain regulates the extent of decarboxylation of 5-hydroxytryptophan, the precursor of serotonin. The results also suggest a continuum from deficiency in pyridoxine to treatment of animals with a moderate excess of pyridoxine which is reflected in the synthesis and secretion into the synaptic cleft of the neurotransmitter serotonin.

Afferent Pathways↗
PubMed1990

The chemical synthesis of the chromogenic substrates, H-D-Val-L-Leu-L-Lys-p-nitroanilide (S2251) and H-D-Ile-L-Pro-L-ARG-p-nitroanilide (S2288).

We describe detailed procedures for the chemical synthesis of two costly chromogenic substrates, H-D-Ile-L-Pro-L-Arg-p-nitroanilide (S2288) and H-D-Val-L-Leu-L-Lys-p-nitroanilide (S2251), which are widely employed for assay of tissue plasminogen activator and plasmin, respectively, as well as in inhibitor assays for these enzymes. Quantities of 5 grams or more of these reagents can be synthesized on a bench-top scale with routine equipment in a laboratory or facility with minimal experience in peptide chemistry. While some of the chemical reactions have been employed previously, improvements have been made therein in this manuscript, and these detailed descriptions are mainly provided to be of service to investigators who employ large quantities of these substrates in their work. The main strategic difference between our methodology and that employed previously is the coupling of the L-Lys- and L-Arg-p-nitroanilides to the previously synthesized, and otherwise completed peptides, which gives superior yields of final product and provides flexibility the chemical synthesis of substrates with other amino acids present.

Chromogenic Compounds↗
PubMed1990

Aortic valve tumor: an unusual cause of coronary obstruction during cardiac catheterization.

Coronary artery obstruction during cardiac catheterization is a rare but serious complication that has been reported to occur in 0.15 to 0.5% of cases. The most common causes of intraprocedural coronary occlusion include thromboembolism, air embolism, and coronary dissection. This report describes the angiographic findings of a patient who developed chest pain with electrocardiographic evidence of myocardial ischemia due to obstruction of the right coronary artery by an aortic valve tumor.

Aortic Valve↗
PubMed1990

An exercise hemodynamic comparison of verapamil, diltiazem, and amlodipine in coronary artery disease.

A prospective, randomized study compared the effects of equivalent intravenous doses of three slow calcium-channel blockers (verapamil, diltiazem, and amlodipine) on rest and exercise haemodynamics in 30 ischemic heart disease patients. Following a stable control period during which rest and exercise (supine bicycle) hemodynamics were assessed, equivalent hypotensive doses of each compound were administered over 20 minutes and rest/exercise parameters were assessed 10 minutes later. At rest all agents similarly reduced systemic blood pressure; the fall in systemic vascular resistance and the increase in cardiac indices was ranked: amlodipine greater than diltiazem greater than verapamil. The heart rate increase for amlodopine differed from verapamil and diltiazem (+19.4% vs. +1.5% vs. -7%; p less than 0.01). On exercise, similarly greater falls in the systemic vascular resistance index followed amlodipine, compared with verapamil and diltiazem (p less than 0.05). Only amlodipine significantly reduced the exercise pulmonary artery occlusion pressure (PAOP). Exercise cardiac stroke volume improved after diltiazem and amlodipine. In terms of cardiac performance, both amlodipine and diltiazem produced an improvement, whereas verapamil depressed cardiac pumping activity. Thus, hemodynamic differences between slow-calcium-channel blocking drugs may be demonstrated in humans. These differences would be compatible with a predominant peripheral vascular site of action for amlodipine, in contrast with mixed cardiac and peripheral sites for diltiazem and verapamil.

Amlodipine↗
PubMed1990

Ultrasonic diagnosis of cirrhosis: reference to quantitative measurements of hepatic dimensions.

Hepatic echo patterns and "right lobe to left lobe longitudinal diameter ratio" were compared in age- and sex-matched 100 normal subjects and 76 patients with diffuse liver diseases (38 cirrhotics and 38 noncirrhotics) in a prospective sonographic study. Various echo patterns, assigned to cirrhotic livers (bright liver, micronodulation, beam attenuation), could not differentiate cirrhosis from other diffuse liver diseases. In cirrhotic livers, the right lobe manifested a significant shrinkage, while the left lobe exhibited almost no alteration. Considering the right to left lobe ratio of 1.30 as a discriminatory value, the cirrhosis could be diagnosed with a sensitivity of 74%, a specificity of 100%, and an accuracy of 93%; the sensitivity rates were seen to be higher in postnecrotic cirrhosis than in alcoholic cirrhosis.

Adolescent↗
PubMed1990

A primate bioassay for the determination of renin inhibitory peptides in serum.

The study of renin inhibitory peptides (RIPs) in rodents and primates requires the establishment of a simple, high volume method for determining the concentration of RIPs in serum after intravenous or oral dosing. The human renin inhibition assay useful for rodents is not directly applicable to primates due to inherent production of angiotensin I from the primate serum angiotensinogen and added recombinant human renin. Therefore, a novel approach to analyze the serum concentrations of RIPs in primates is described based on in vitro studies with monkey serum. The procedure involves the inactivation of monkey angiotensinogen and monkey renin by thermal denaturation prior to analysis. Application of this assay was demonstrated by analyzing serum samples from an in vivo study in monkeys using ditekiren (U-71,038), a renin inhibitory peptide, and by validation of the assay and results using a tritium-based radioimmunoassay (RIA) for ditekiren. The minimum detectable limit of ditekiren for both the RIA and the bioassay for primates was 10ng/ml serum. The reported bioassay should be of value for monitoring serum levels of thermostable RIPs from pharmacokinetic, bioavailability, and pharmacodynamic studies in primates as well as in humans.

Administration, Oral↗
PubMed1990

The use of percutaneous diversion during pregnancy.

Two patients with infected hydronephrosis and one patient with calculus anuria during pregnancy were managed initially by percutaneous nephrostomy. Maintenance of percutaneous diversion allowed continuation of pregnancy to term and effectively preserved renal function. Definite surgical treatment for the obstructive pathology was done electively in the postpartum period.

Adult↗