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Biomedical subjects

R V Singh

Publications and source records attributed to R V Singh.

33 records · Page 2Linked to original sources
PubMed1993

Spinal extradural cavernous angioma.

A case of spinal extradural cavernous angioma is described. The symptomatology and prognosis of such lesions is discussed and the relevant literature reviewed.

Adult↗
PubMed1992

The human glutathione S-transferases: comparison of isoenzyme expression in normal and astrocytoma brain.

We describe expression of alpha, mu and pi class glutathione S-transferases (GST) in brain tissue from 21 controls and uninfiltrated and tumour tissue from 17 glioma patients. GST were sequentially resolved by chromatofocusing into the GST2, GST1, GST5, GST2 (5.5), GST3, GST6 sets and the contribution of each to total activity determined. The immunological identity of these isoforms was studied using immunoblotting. The pi class GST3 isoform was the major contributor to activity in control tissue (70.9%) and, uninfiltrated (75.1%) and tumour samples (82.4%). Expression was significantly greater in the tumours (P less than 0.05). Expression of alpha isoforms GST2 and GST2 (5.5) was variable with most subjects demonstrating no detectable GST2 (B1 and B2 chromatofocused monomers). An isoform termed GST2 (5.5) chromatofocussed at pH 5.5 and cross-reacted with antisera to B1. It was detected in most control and glioma patients and comprised about 5% of total activity. The contribution of GST2 and GST2 (5.5) to activity was similar in control, uninfiltrated and tumour tissue. Two mu class enzymes, GST1 and GST5, were identified. GST1 isoforms were detected in 9 of 21 control samples, the phenotype of these and matched liver samples were identical. GST1 isoforms were detected in 4 of 16 tumour samples, a significantly lower incidence than in a previously established control group. GST5 was expressed in most samples, the contribution of this locus to activity was significantly reduced in the tumours (5.2%) compared with control samples (14.5%).

Astrocytoma↗
PubMed1990

Stereochemical and biochemical aspects of some organoboron complexes of sulphur donor ligands.

Synthetic, structural and biochemical aspects of some organoboron complexes of sulphur containing ligands having ONS and SNNS donor systems have been described. The ligands were prepared by the condensation of 1-phenyl-1,3-butanedione, 2,4-pentanedione, diphenylethanedione, 2,3-butanedione, ethanedial and 1,4-benzenedialdehyde with 2-mercaptoaniline. The unimolar reactions between phenylboronic acid and these thio-ligands have produced Ph.B (ONS) and Ph.B. (SNNS) type of biologically active complexes. These have been characterized by elemental analysis, molecular weight determinations, and conductivity measurements. Based on UV, IR, 1H NMR, 13C NMR and 11B NMR spectral studies, a tetracoordinated state of boron has been established in all the derivatives. The ligands and their corresponding organoboron complexes have been tested in vitro against a number of pathogenic fungi and bacteria and found to possess remarkable fungicidal and bactericidal properties.

Anti-Bacterial Agents↗
PubMed1990

Coordination behavior and antifungicidal, antibacterial, and antifertility activities of dioxomolybdenum(VI) complexes of biologically active heterocyclic benzothiazolines.

Synthesis, characterization, and structural aspects of a new class of dioxomolybdenum(VI) complexes with biologically active benzothiazolines, 2-(2-pyridyl) benzothiazoline, 2-(2-thienyl) benzothiazoline, 2-(2-furyl) benzothiazoline, 2-(3-indolyl) benzothiazoline, glyoxal benzothiazoline, biacetylbenzothiazoline, benzil benzothiazoline, and terphthaldehyde benzothiazoline have been described. The newly synthesized complexes, [MoO2(Bzt)2] and [MoO2(Bzt')] (where BztH and Bzt'H2 represent benzothazoline molecules) have been characterized by elemental analysis, conductance measurements, molecular weight determinations, and magnetic studies. Based on IR, 1H NMR, 13C NMR, and electronic spectral studies, distorted octahedral geometry with cis-MoO2 group has been indicated for the resulting complexes. Two benzothiazolines and their corresponding metal complexes were screened for their antifungicidal and antibacterial activity on several fungi and bacteria and found to be quite active in this respect. In addition, antifertility activity of representative ligands and their molybdenum complexes was also evaluated and discussed in male mice.

Animals↗
PubMed1990

Schwannoma of the oculomotor nerve.

A case is described of oculomotor nerve sheath tumour presenting with signs and symptoms of a posterior fossa space occupying lesion with minimal involvement of the IIIrd nerve.

Adult↗
PubMed1977

Intrahepatic arterial infusion of combination of mitomycin-C and 5-fluorouracil in treatment of primary and metastatic liver carcinoma.

Improvement in drug response and reduction of toxicity were observed after continuous intrahepatic arterial infusion of mytomycin-C (MMC) and 5-fluorouracil (5-FU) in 15 of 26 patients with primary or metastatic carcinoma of the liver. Serum bilirubin values of 10 mg/100 ml absence of ascites, extreme cachexia and impending hepatic failure were used as the criteria for admission of these patients into the study. The patients were given MMC in a dose of 0.08 mg/kg on day 1,5-FU in a dose of 8-10 mg/kg on days 2-5, and MMC on day 6. This schedule was reinitiated on days 8 and 15 for total mean duration of 18 days. Maintenance therapy was carried out by the administration of these drugs at induction dosage alternated each week as a single 24 hourly intravenous infusion. Objective response to combination therapy was defined as decrease of at least 50% in the liver size and in the abnormal levels of serum alkaline phosphatase and glutamic oxaloacetic transaminase (SGOT), and near normal levels of serum bilirubin for a minimum period of 2 months. The duration of objective response ranged from 3-16 months with a median of 8.2 months. The median survival time for the responders was 7.2 months for patients with primary carcinoma and 9.4 months for patients with metastatic carcinoma of the liver as compared to 2 months for patients who failed to respond to the treatment. Five out of 12 patients who were refractory to MMC or 5-FU by intravenous infusion responded to the present combination drug therapy. Of four patients who died during induction therapy, three had liver failure and the fourth suffered pulmonary embolism. These studies provide evidence that combination therapy with MMC and 5-FU increases the survival time of patients with hepatic cancer, presumably due to the synergistic action of these drugs which permits the use of a low dosage schedule and has less toxic effects.

Adult↗
PubMedDate not supplied

Synthesis and pharmacological studies of some 2-t-amino and 2,3-di-t-amino substituted 1,4-naphthoquinones and related compounds.

Series of 2-t-amino and 2,3-di-t-amino substituted-1,4-naphthoquinones have been synthesised from corresponding 1,4-naphthoquinones by reaction with secondary amines. The compounds have been evaluated for their broad spectrum antimicrobial, antiviral and anticancer activity. In the preliminary screening results 8a and 9a have shown profile of an antimicrobial agent.

Animals↗