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Biomedical subjects

A Sharma

Publications and source records attributed to A Sharma.

At least 847 records · Page 47Linked to original sources
PubMed1988

Scleral tuberculosis.

A rare case of scleral tuberculosis manifesting as an ulcerative scleral nodule is described. Corroborative evidence of systemic tuberculous lesions was detectable. The lesion responded to antituberculous treatment alone.

Adult↗
PubMed1988

Effects of stannic chloride on human leucocytes in vitro.

Single dose treatment with stannic chloride (4 micrograms/ml) on human lymphocytes in vitro revealed a significant increase of chromosomal aberrations. These showed a distinct relationship with the donor's age. Single and isochromatid breaks including gaps, premature chromosome condensation, irregular staining, stretching of the centromere and interchange, i.e. quadriradial exchange of chromosome arms, and also aneuploidy, were observed.

Dose-Response Relationship, Drug↗
PubMed1987

Effects of metals on chromosomes of higher organisms.

An analysis of the available data on the clastogenic effects of metals and their compounds on higher organisms indicates some general trends. Following chronic exposure to subtoxic doses, a decrease in mitotic frequency and an increase in the number of chromosomal abnormalities are observed. These effects are usually directly proportional to the dose applied and the duration of treatment within the threshold limits. Recovery after acute treatment is inversely related to the dosage. The ultimate expression of the effects depends on certain factors, including the mode and vehicle of administration; the form administered; the test system used; the rate of detoxification, distribution, and retention in the different tissues; and interaction with foreign and endogenous substances as well as the mode of action with the biological macromolecules. In mammals, the clastogenic activity of the metals within each vertical group of the periodic table is directly proportional to the increase in atomic weight, electropositivity, and solubility of the metallic cations in water and lipids, except for Li and Ba. This pattern of inherent cytotoxicity increases with successive periods in the horizontal level. It is enhanced by the formation of covalent and coordinate covalent complexes by heavy metals with the biological macromolecules. In plants, the solubility of the metals in water is of much greater importance. The degree of dissociation of metallic salts and the rate of absorption affect significantly the frequency of chromosomal aberrations. In assessing the effects of environmental metal pollution, the presence of other metals and toxic chemicals and the level of nutrition should be taken into account, since in nature, metals occur in combination and these factors modify the cytotoxic effects to a significant extent.

Animals↗
PubMed1987

Antagonistic and synergistic effects of lead and selenium in Rattus norvegicus.

Female rats were administered intraperitoneal injections of solutions of lead acetate and sodium selenite. The salt solutions were given singly to 'control' animals and successively to the 'treated' animals in both chronic and acute treatments but with or without a time gap of 1 h in the latter treatment. In the chronic treatments the dosage of lead acetate was kept constant and that of sodium selenite varied while in the acute treatments the ratio of the two salts was kept constant. Degrees of protection afforded by sodium selenite against chromosomal damage caused by lead acetate were assessed.

Animals↗
PubMed1987

A method for the sequential colorimetric determination of serum triglycerides and cholesterol.

A simple spectrophotometric method for the sequential determination of triglycerides and cholesterol from a single serum sample was developed. In this two-stage procedure, the triglycerides and cholesterol esters are first hydrolysed to glycerol and free cholesterol respectively, with simultaneous scavenging of the liberated free fatty acids, a technique that ensures clarity of the sample. The glycerol is subsequently reacted to result in an intense red chromogen with a peak absorption maximum at 510 nm following a series of enzymic reactions. In the second stage, addition of cholesterol oxidase leads to oxidation of free cholesterol generated from the cholesterol esters in the first stage and the free cholesterol normally present in the sample, yielding in a similar fashion the identical red chromogen whose absorbance is also measured at 510 nm. Results obtained with the proposed method demonstrate good correlation with established individual procedures for triglycerides and cholesterol.

Bilirubin↗
PubMed1987

High risk suicide factors across cultures.

High risk suicide factors both in India and in the United States are examined. In India these are: humiliation, reputational and economic loss, poverty, examination failure, relationship disappointments, disputes with spouse and inlaws, property disputes, loss of loved one, and chronic medical illnesses. In the United States major depressions, schizophrenia, alcoholism, recent loss(es), retirement, limited social support system, age over 45 and high risk low rescue situations are significant. Most of high risk suicide factors in India apparently are related to interpersonal and socioeconomic causes, whereas in the United States these relate to individual and psychiatric causes. These interesting differences are discussed.

Adolescent↗
PubMed1987

Ultrastructural and clinicopathological studies on the toxicity of cationic acrylamide-based flocculant to rainbow trout.

Rainbow trout (Salmo gairdneri) of two age groups were exposed to a cationic acrylamide-based flocculant at various concentrations in static bioassay chambers. At lethal concentrations the flocculant produced severe gill alterations in all fish. The principal alterations were necrosis and separation of the respiratory epithelial cells covering secondary lamellae. Many necrotic chloride cells were also seen, their apical plasma membrane was destroyed, and mitochondria were swollen with separated cristae. An influx of a large amount of fluid into the interstitial spaces caused partial or complete separation of subepithelial spaces from the covering epithelial cells and basement membranes of underlying blood vessels. Clinicopathological alterations included marked decreases in blood pH, partial pressure of oxygen, bicarbonate and plasma sodium, and chloride concentrations. Hematocrit, total protein, and blood glucose were increased. Fish exposed to sublethal concentrations had gill alterations characterized by hypercellularity and thickening of the secondary lamellae. These were due to undifferentiated cell proliferation and macrophage and lymphocyte infiltration between the covering epithelial cells and the underlying blood vessels. Macrophages and undifferentiated cells had large phagolysosomes containing cytoplasmic organelles, an indication of cell injury and increased turnover.

Acrylamides↗
PubMed1987

Effect of vehicular volume on the early pulmonary injury and inflammatory response in rats inoculated intratracheally with silica.

The effect of vehicular saline solution volume on early lesions induced in rats by intratracheal administration of silica was evaluated. Seventy-two male Long-Evans rats were randomly assigned 6 each to 12 factorial groups (3 X 2 X 2): 3 doses of silica (0, 2.5, and 5 mg), 2 volumes of vehicle (saline solution; 0.1 and 0.5 ml), and 2 postinoculation times (1 and 3 days). Lactate dehydrogenase and alkaline phosphatase activities in the bronchoalveolar lavage fluid supernatant and cell viability of bronchoalveolar cells were used as indicators of cell injury. The number of pulmonary alveolar macrophages and polymorphonuclear leukocytes were used as indicators of inflammatory response. Dose of silica and postinoculation time had a significant (P less than 0.05) effect on the biochemical and cellular composition of lavage fluid. The volume of vehicle in which silica was suspended significantly (P less than 0.05) enhanced the pulmonary injury and inflammatory response. However, dose-volume interaction was only significant (P less than 0.05) in 1 of 6 parameters, indicating that the effect was additive, but not synergistic, in nature. Seemingly, vehicle volume had an enhanced effect on the injury and the inflammatory response induced by intratracheal inoculation of silica.

Animals↗
PubMed1987

Mitomycin C induced chromosomal aberrations and sister chromatid exchanges (SCEs) in lymphocytes of patients with precancerous and cancerous lesions of the uterine cervix.

Baseline and mitomycin C (MMC)-induced chromosomal aberrations and sister chromatid exchanges (SCEs) in blood lymphocytes of patients with cervical precancerous and cancerous lesions and normal women were studied. The baseline frequency of chromosomal aberrations and SCEs revealed a significant increase in higher grades of precancerous (moderate and severe dysplasias) and cancerous lesions compared to those of controls. The MMC-induced chromosomal aberrations and SCEs did not show any differential response in the different groups studied. The results thus indicate that chromosomal instability as observed in precancerous and cancerous lesions is not associated with their sensitivity to mitomycin C.

Chromosome Aberrations↗