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Biomedical subjects

S C Sahu

Publications and source records attributed to S C Sahu.

At least 37 records · Page 2Linked to original sources
PubMed1991

Quercetin-induced lipid peroxidation and DNA damage in isolated rat-liver nuclei.

The extent of lipid peroxidation and DNA damage induced by quercetin were studied under aerobic conditions in isolated rat-liver nuclei. The effects of iron and copper ions on these two toxic oxidative processes were also investigated. Quercetin induced significant (P less than 0.05) concentration-dependent nuclear lipid peroxidation concurrent with DNA degradation; these effects were enhanced by iron and copper ions. The results suggest that the reactive oxygen species generated by quercetin autoxidation, catalyzed by iron and copper ions, are responsible for the concurrent lipid peroxidation and DNA damage in isolated rat-liver nuclei.

Animals↗
PubMed1991

Iron-mediated oxidative DNA damage detected by fluorometric analysis of DNA unwinding in isolated rat liver nuclei.

Studies were performed to determine the extent of nuclear DNA degradation induced by iron, iron-ascorbate, or iron-bleomycin under aerobic conditions in a model system using isolated rat liver nuclei. The effects of five antioxidants (catalase, superoxide dismutase, dimethyl sulfoxide, glutathione and diallyl sulfide) on this oxidative nuclear damage were also investigated. At the 0.05 level for statistical significance, iron induced concentration-dependent DNA degradation, and this effect was enhanced by ascorbate and bleomycin. The antioxidants catalase, dimethyl sulfoxide, and diallyl sulfide significantly reduced the iron-ascorbate-induced DNA damage, whereas superoxide dismutase and dimethyl sulfoxide significantly reduced iron-bleomycin-induced damage. Glutathione significantly increased the iron-bleomycin-induced DNA damage. These results suggest that the reactive oxygen species generated by iron, iron-ascorbate, and iron-bleomycin are responsible for the DNA strand breaks in isolated rat liver nuclei.

Animals↗
PubMed1990

Oncogenes, oncogenesis, and oxygen radicals.

The role that free radicals in general and oxygen radicals in particular play in carcinogenesis has attracted considerable attention in recent years. The oxygen radicals are undesirable but inevitable products of aerobic metabolism in the normal living cell. The cellular antioxidant defense system maintains an appropriate balance between necessary oxidative events and those that are excessive. When this critical balance cannot be maintained because of the overloading of the cellular redox system, oxygen radicals can induce cell damage. They can influence carcinogenesis by inducing DNA damage from direct oxidation or indirectly from DNA-binding products of lipid peroxidation. Oxygen radicals can induce conformational changes in the plasma membrane by lipid peroxidation and protein degradation, thus influencing membrane-associated cellular activities. They are capable of affecting membrane-bound protein kinases, growth factors and their receptors, and, therefore, signal transduction and oncogene activation. Thus, the oxygen radicals can have a major influence on oncogenes and oncogenesis.

Animals↗
PubMed1982

Biochemical response of rat lung to inhaled n-hexane.

Biochemical response of the rat lung to inhaled n-hexane was investigated. Dose-dependent increase in protein, lipid, sialic acid, lactate dehydrogenase, angiotensin-converting enzyme, acid and alkaline phosphatase was observed in the cell-free lavage effluent of the lungs of exposed rats compared to the control animals. This was interpreted as enhanced pulmonary secretions accompanied by increased cell damage.

Animals↗
PubMed1982

A psychiatric study of amputees.

Psychiatric manifestations were studied in 72 amputees in the post-operative period. All were right handed. Besides phantom limb phenomena, which were observed in nearly four-fifths of the cases and are described in another paper, nearly two-thirds had psychiatric symptoms inthe form of depression (45 patients), anxiety (38), crying spells (38), insomnia (34), loss of appetite (23), suicidal ideas (21) and psychotic behaviour (2). Right arm amputees had phantom phenomena and insomnia significantly more often than left. Nearly one-fifth of the cases were diagnosed as having psychotic depressive reactions, two-fifths as having depressive neurosis and two, both with right upper limb amputations, as schizophrenic.

Adolescent↗
PubMed1982

Phantom limb: a phenomenological study.

Phantom limb phenomena during the post-operative period were studied in 72 amputees. All were right handed. Phantom limb was present in 86.1 per cent of the cases, significantly more commonly amputation of the right arm. Nearly half of the phantoms developed within the first 24 hours and another quarter in the next 24 hours, appearing earlier in lower limb amputees. Movements in the phantom were felt by three-quarters of the cases, an incidence unaffected by site or side of amputation. Telescopy was present in nearly two-thirds and phantom limb pain in over two-thirds, significantly more commonly in the upper limb amputees but uninfluenced by the side of amputation. Thirty-one of the patients dreamed that their limbs were intact.

Adolescent↗
PubMed1981

Failure of adrenalectomy to prevent the male-induced pregnancy block (Bruce effect) in mice.

Adrenalectomy failed to prevent the ovoimplantation block that occurs in newly mated female mice following exposure to alien males. No difference in the percentage of pregnancy failure in adrenalectomized females as compared with sham-operated or intact females was noted. It is concluded that the pituitary-adrenal axis is not involved in the Bruce effect and the stress-response does not adequately account for the neuroendocrine changes induced in newly mated females following exposure to alien males that lead to ovoimplantation failure.

Adrenal Glands↗
PubMed1980

Hyaluronic acid. An indicator of pathological conditions of human lungs?

Hyaluronic acid was the only glycosaminoglycan found in detectable amounts in the pulmonary secretions of patients with cystic fibrosis. The compound gave a hexuronate/hexosamines molar ratio of approximately 1. Glucosamine represented over 98% of the total hexosamines, the remainder being galactosamine. No hexoses or sulfate could be detected. It moved as a single spot with the mobility of standard hyaluronic acid on cellulose acetate electrophoresis and this spot disappeared after digestion with testicular hyaluronidase. It was associated with trace amounts of protein, the major amino acids of which are aspartic acid, glutamic acid, glycine, and alanine.

Amino Acids↗
PubMed1980

Hyaluronic acid--an indicator of pulmonary injury?

Hyaluronic acid was the only glysosaminoglycan detected in the pulmonary secretions of healthy adult rats exposed to inhalation to methylene chloride, but not of control animals. The compound migrated as a single spot with the mobility of standard hyaluronic acid on cellulose acetate electrophoresis and disappeared after digestion with testicular hyaluronidase. Its identification was confirmed by finding hexuronate/hexosamine in a molar ratio of approx. 1. Glucosamine represented over 97% of the total hexosamine, the remaining 3% being galactosamine. No hexose or sulfate could be detected. Sodium dodecyl sulfate--polyacrylamide gel electrophoresis showed no protein associated with this glycosaminoglycan. It appears that the secretion of hyaluronic acid into the airways may be the result of pulmonary inflammation induced by the toxic effects of methylene chloride.

Animals↗
PubMed1977

Investigations of black bronchoalveolar human lavage fluid.

The removal by bronchoalveolar lavage (two occasions) of 10(11) black macrophages containing crystals of aluminum silicate, large amounts of amorphous carbon, and oxidized lipids was followed by considerable improvement in gas exchange in a patient. Sixty-eight percent of these pulmonary macrophages were viable and normal, as judged by chemotatctic and phagocytic activity. Except for cigarettes, no source for the previously mentioned ingested foreign substances was found. These observations suggest that removal by lavage of nonviable macrophages laden with foreign bodies from distal portions of the lungs of pulmonary patients may be therapeutically useful.

Carbon↗