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Biomedical subjects

S K Aggarwal

Publications and source records attributed to S K Aggarwal.

At least 91 records · Page 5Linked to original sources
PubMed1983

Embryotoxicity of cisplatin in rats and mice.

Cisplatin [cis-dichlorodiammineplatinum (II)], a broad spectrum antitumor agent, was tested for possible teratogenic and embryolethal effects on Wistar rats and Swiss Webster mice. Rats were given a single ip injection of 0.3, 1.0, 2.5, or 3.0 mg/kg cisplatin on Day 6, 8, 11, or 14 of gestation, whereas mice were given a single ip injection of 0.3, 3.0, 6.0, 8,0, or 13.0 mg/kg on Day 8 only. The embryonic LD50's in the rat were 2.88, 1.28, and 1.0 mg/kg for day 6, 8, and 11, respectively. There was no significant increase in embryolethality at any of the doses given on Day 14. The embryonic LD50 for mice was 5.24 mg/kg. An increase in the incidence of growth retardation or gross malformations was not discernable in the surviving fetuses with the number of dams used in this study. Cisplatin is highly embryolethal in rats and mice at dosages well below the adult therapeutic dosage in humans. This embryolethality is gestational stage-specific with the highest mortality corresponding to the period of rapid DNA replication in early organogenesis.

Animals↗
PubMed1983

Effect of cisplatin on the plasma membrane phosphatase activities in ascites sarcoma-180 cells: a cytochemical study.

To study the effects of cisplatin [cis-dichlorodiammine-platinum (II)] on tumor cells in the presence or absence of the immune system, animals with ascites sarcoma-180 tumor burden were treated with therapeutic dose levels (9 mg/kg). Similarly, ascites sarcoma-180 cells were maintained in tissue culture media containing the same levels of the drug. Cell samples were taken from the animals at 12-hr intervals for 3 days, whereas samples were drawn from the tissue cultures at 15-, 30-, 45-, and 60-min and at 2-, 3-, 4-, and 5-hr intervals. Treated and untreated cells from in vitro and in vivo experiments, when checked for alkaline phosphatase, 5'-nucleotidase, Ca2+-ATPase, and Na+-K+-ATPase, show a gradual decrease in activity on the plasma membrane. It takes about 60 min for inactivation of any enzyme in vitro, whereas it takes 2 days in in vivo experiments. Quantitative analysis show alkaline phosphatase activity drops from 9.7 to 4.9 nmol in just 15 min, and drops further to 0.79 nmol after 2 hr. Inactivation of various plasma membrane enzymes, resulting in permeability changes, is probably responsible for cell death.

5'-Nucleotidase↗
PubMed1983

Precipitation of type-I (upgrading) reaction in leprosy by skin testing with antigen and irritants.

Twenty patients of various types of leprosy were skin tested with lepromin, PPD and DNCB to assess their immunological status. Two of the twenty (18 BT; 2 BB) patients belonging to BT type developed signs of acute neuritis of sudden onset about 4 weeks after the test with DNCB, lepromin and PPD. The patients were on DDS therapy already for the last 3-4 months. Presumably DNCB, PPD or lepromin testing had precipitated the reaction. A suggestion is made that lepromin a lower concentration could be used initially and if it gives negative reaction, a higher concentration may be used as in case of PPD testing, particularly in TT and BT cases already put on treatment.

Adult↗
PubMed1980

Platinum drugs: combined anti-lymphoproliferative and nephrotoxicity assay in rats.

A 4-day drug schedule was used to explore the efficacy and simultaneous toxicity of cisplatin and 30 other platinum (II) amines given IP to PVG x Lew F1 hybrid rats at cumulative doses of 10-300 mumol/kg. Toxic effects monitored were stomach enlargement, kidney hypertrophy with tubular necrosis and proteinuria, evident visceral mucin, and lymphoid involution (thymus, spleen). Immunosuppressive effects were monitored as inhibition of the lymph node hypertrophy induced by grafting PVG spleen cells into each paw of F1 hybrids. No significant activity/toxicity was observed with 'platinum-(pyrimidine) blues'. N-alkyl derivatives of cisplatin were less active/toxic and some had no immunosuppressant effect, though they are reported as effective antitumour agents (in mice). mu-Hydroxobridged aminoplatinum (II) dimers were highly toxic, effective immunosuppressants and their toxicity profiles were distinct from the dihalo or diaquo diaminoplatinum species. 1,2-Diaminocyclohexane platinum derivatives showed a wide range of potency, all being much less nephrotoxic than cisplatin.

Animals↗
PubMed1977

Further evidence in support of cell-surface-associated deoxyribonucleic acid in tumor cells: an autoradiographic study.

Ascites sarcoma-180 cells, when stained with platinum-pyrimidine complexes as the sole electron dense stain, show distinct dense patches to granular appearance on the surface of the plasma membrane which has been suggested to be attributable to deoxyribonucleic acid. Swiss Webster mice, 4-5 weeks of age, weighing 24-26 g with 4 X 10(6) ascites sarcoma-180 cells when injected with 3 X 7.0 micronC of tritiated thymidine on day 5 of the tumor implant, show specific labeling on the plasma membrane surface. The photopositive silver grain distribution in both the light and electron microscope autoradiograms when followed from the nucleus outwards show a distinct peak over the nucleus and the plasma membrane. The quantity and origin and role of this surface-associated deoxyribonucleic acid is not clear.

Animals↗
PubMed1976

Platinum-pyrimidine complexes for electron microscopic cytochemistry of deoxyribonucleic acid.

Platinum-pyrimidine complexes that are amorphous and highly soluble in water when used as sole electron-dense stains show high selectivity for nucleic acid-rich areas like chromatin, nucleolus and ribosomes. A method is presented for the selective staining of deoxyribonucleic acid. Glutaraldehyde-fixed tissue are exposed to 3 N HCL hydrolysis for an optimum time of 1 hr at room temperature before being embedded in Epon. Thin sections are then exposed to Schiff's reagent for 30 min and treated with 1% platinum-pyrimidine complex. The results inselective staining of structures containing deoxyribonucleic acid.

Animals↗
PubMed1975

Cell-surface-associated nucleic acid in tumorigenic cells made visible with platinum-pyrimidine complexes by electron microscopy.

Platinum-pyrimidine complexes have been used as the sole electron-dense stains for electron microscopy on 18 types of mammalian cells. These recently discovered complexes react avidly with nucleic acids in vitro, are antitumor agents, and are highly soluble in water. In cells, they are selective for regions rich in nucleic acid and make visible the cellular chromatin, nucleolus, and ribosomes. In addition, cells that are tumorigenic exhibit electron-dense patches at the plasma membrane; normal cells do not. The results of treatment of ascites sarcoma-180 cells with concanavalin A, nucleases, glycosidases, or a protease suggest that the electron-dense patches are DNA, with neuroaminic acid involved in the surface binding.

Animals↗