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Biomedical subjects

S K Sharma

Publications and source records attributed to S K Sharma.

At least 469 records · Page 26Linked to original sources
PubMed1988

A cytotoxic agent can be generated selectively at cancer sites.

Attempts to improve the selectivity of anti-cancer agents by conjugating them to antibodies directed at tumour associated antigens have demonstrated tumour localisation but only limited therapeutic success. We report here the advantage of a 2-stage approach in which the first component combines the selective delivery of antibody with a capability to generate a cytotoxic agent from a second subsequently administered component. A bacterial enzyme, carboxypeptidase G2 (CPG2) was conjugated with F(ab')2 fragment of a monoclonal antibody directed at beta subunit of human chorionic gonadotrophin (beta-hCG) and injected into nude mice bearing hCG producing CC3 xenografts of human choriocarcinoma. Time was allowed for the conjugate to localise at tumour sites and clear from blood before injecting para-N-bis (2-chloroethyl) aminobenzoylglutamic acid. Cleavage of the glutamic acid moiety from this molecule by CPG2 released a benzoic acid mustard. Growth of the tumour which is resistant to conventional chemotherapy was markedly depressed by a single course of treatment. This demonstrates for the first time the potential of an antibody directed enzyme to activate an alkylating agent and to eradicate an established human cancer xenograft.

4-Aminobenzoic Acid↗
PubMed1988

Benign periurethral mass lesions: the female prostate.

Bladder outflow obstruction in the female is usually a functional complaint, but rarely may be of organic aetiology, due to peri-urethral mass lesions. These lesions are usually midline in location and present clinical and roentgenological features comparable with those of prostate in the male. Two such patients, one of pure fibroma and another of hyperplastic glandular tissue are presented and their management is discussed.

Female↗
PubMed1988

Vesicopyelostomy in the treatment of pelvic kidneys with pelviureteric junction obstruction: long-term follow-up.

The surgical management of 6 male patients with pelvic kidneys with pelviureteric junction obstruction is discussed. Two patients presented in advanced renal failure and 1 had peritonitis and septicaemia due to rupture of the renal pelvis. Vesicopyelostomy was preferred to pyeloplasty in 5 patients because of adhesions, multiple aberrant vessels, multiple stones, malrotation and the low pelvic position, but pyeloplasty was done in 1 case. Though vesicoureteric reflux was observed during voiding cystourethrography in all patients, no deleterious effect on the kidney was seen during the 3- to 5-year follow-up period.

Adolescent↗
PubMed1988

Glucocorticoid receptors in bronchoalveolar lavage fluid in sarcoidosis. A preliminary report.

Glucocorticoid receptor (GR) content was measured in bronchoalveolar lavage fluid (BALF) cells of 20 untreated patients with sarcoidosis. A significantly higher (p less than 0.001) lymphocyte count and GR content of BALF cells was noted in patients with sarcoidosis as compared to normal volunteers. The GR content correlated positively with lymphocytes (%) (r = 0.6; p less than 0.01) and was significantly higher (p less than 0.001) in patients who showed roentgenographic improvement, physiologic improvement, and improvement in both parameters compared to those who did not show improvement. Above findings suggest that the GR content of BALF cells is increased in sarcoidosis and a major contribution to this may be made by the lymphocytes.

Adult↗
PubMed1988

Novel compositions of emulsified perfluorochemicals for biological uses.

Physico-chemical characteristics of novel perfluorodecalin emulsions stabilized against Ostwald ripening by the addition of polycyclic, perfluorinated oil additives are described. The effects of varying both oil additive and emulsifier concentrations have been examined. Stabilizing effects of additives were found to be related to molecular weight and hence, boiling point and vapour pressure.

Blood Substitutes↗
PubMed1988

Biocompatibility studies with a novel perfluorochemical emulsion.

Biocompatibility studies with a novel perfluorochemical (PFC) emulsion have been performed in rats. Injection of the emulsion was followed by changes in lymphoid tissue weights, comparable but not identical to those produced by the commercial formulation, Fluosol-DA 20% (F-DA). Peritoneal injection of either the novel emulsion or F-DA enhanced the humoral immune response to intraperitoneally-injected sheep red blood cells (SRBC) suggesting immunopotentiating properties of emulsion components.

Animals↗
PubMed1988

Active human tissue plasminogen activator secreted from insect cells using a baculovirus vector.

A baculovirus expression vector was constructed with the tissue plasminogen activator (TPA) cDNA under the control of the viral polyhedrin promoter. After infection of insect cells with the recombinant baculovirus, active TPA was secreted into the medium in which these cells were grown. TPA was isolated from the conditioned media using metal chelate affinity chromatography followed by immunoaffinity purification using mouse monoclonal anti-human TPA coupled to Sepharose. Sodium dodecyl sulfate-gel electrophoresis under reducing conditions and sequence analysis of recombinant human TPA have revealed a two-chain form of the enzyme. The N-terminal amino acid was identified to be serine, indicating that it was processed at its N-terminus by the insect cell culture in a manner similar to that observed for mammalian cells. The relative specific activity of recombinant TPA from insect cells is comparable to that of Bowes melanoma TPA standard. Its activity is stimulated in the presence of fibrinogen fragments, but by a factor about 2.3-fold lower than the Bowes melanoma TPA. The apparent molecular weight of recombinant TPA from insect cells was about 60K by fibrin agar activity gels, suggesting less complex glycosylation than recombinant TPA from mammalian cells.

Amino Acids↗
PubMed1988

Bio-environmental control of malaria in an industrial complex at Hardwar (U.P.), India.

A study on the bio-environmental control of industrial malaria was launched at Bharat Heavy Electricals Ltd., the country's foremost industrial complex. Malaria was a serious problem on the campus of the complex and routine methods of malaria control by providing screened doors, larviciding, fogging, limited spraying in the unauthorized colonies and chemotherapy were not effective. The project staff diverted the existing resources to reduce mosquito breeding sites by using fly ash to fill low lying areas, borrow pits and ditches, etc.; cleaning blocked drains and improving drainage by constructing cemented drains, mosquito-proofing overhead water storage tanks, improving surveillance and chemotherapy and introducing developmental schemes to make it a holistic process. The entire campus was brought under the alternate strategy during a 5 month period. In less than one year indigenous transmission was interrupted and the areas brought under maintenance at a cost of US +28,000. The study showed that in this instance malaria control should first be based on source reduction rather than insecticidal methods.

Animals↗