PubMed Health⌕ Search

Biomedical subjects

S C Sahu

Publications and source records attributed to S C Sahu.

At least 19 recordsLinked to original sources
PubMed1996

Pro-oxidant activity of flavonoids: effects on glutathione and glutathione S-transferase in isolated rat liver nuclei.

The effects of three representative flavonoids, quercetin, myricetin and kaempferol, on the nuclear antioxidant defense glutathione (GSH) and glutathione S-transferase (GST) were investigated in a model system of isolated rat liver nuclei. The three flavonoids induced a concentration-dependent decrease of both the nuclear GSH content and GST activity. Myricetin, which has the maximum number of hydroxyl groups, was the most active. The results demonstrate the pro-oxidant activity of these polyphenolic flavonoids. The impairment of the nuclear antioxidant defense GSH and GST by the polyphenolic flavonoids can lead to oxidative DNA damage, which may be responsible for their mutagenicity.

Animals↗
PubMed1994

Kaempferol-induced nuclear DNA damage and lipid peroxidation.

The extent of DNA damage and lipid peroxidation induced by kaempferol, a polyphenolic flavonoid with a molecular structure similar to quercetin, was studied under aerobic conditions in isolated rat-liver nuclei. Kaempferol induced significant (P < 0.05) concentration-dependent nuclear DNA degradation concurrent with lipid peroxidation; these effects were enhanced by iron(III) or copper(II). Catalase, superoxide dismutase (SOD), mannitol, and sodium azide did not show any inhibitory effect on the kaempferol-induced nuclear DNA damage in the presence of iron(III) or copper(II). On the other hand, all stimulated the kaempferol-induced DNA damage in the presence of iron(III); in the presence of copper(II) only SOD and mannitol showed statistically significant stimulatory effects. The kaempferol induced lipid peroxidation was significantly stimulated by catalase and sodium azide in the presence of iron(III). These results demonstrate the pro-oxidant properties of polyphenolic flavonoids, which are generally considered as antioxidants and anticarcinogens, suggesting their possible dual role in mutagenesis and carcinogenesis.

Animals↗
PubMed1993

Interactions of flavonoids, trace metals, and oxygen: nuclear DNA damage and lipid peroxidation induced by myricetin.

The extent of DNA damage and lipid peroxidation induced by myricetin, a polyphenolic flavonoid, were studied in isolated rat liver nuclei under aerobic conditions. Myricetin induced significant (P < 0.05) concentration-dependent nuclear DNA degradation concurrent with lipid peroxidation; these effects were enhanced by iron (III) or copper (II). Catalase, superoxide dismutase (SOD), mannitol and sodium azide did not inhibit myricetin-induced nuclear DNA damage in the presence of iron (III) or copper (II). However, all of these antioxidants stimulated myricetin-induced DNA damage in the presence of copper (II). Lipid peroxidation induced by myricetin was significantly inhibited only by SOD in the presence of copper (II), whereas it was enhanced by catalase and sodium azide in the presence of iron (III). These results demonstrate the pro-oxidant properties of polyphenolic flavonoids, which are generally considered to be antioxidants and anticarcinogens, and suggest a dual role for these flavonoids in mutagenesis and carcinogenesis.

Animals↗
PubMed1993

Ipsilateral concomitant fractures of the femoral neck and shaft.

This paper is presented to review the treatment and diagnostic difficulties in cases of combined ipsilateral fracture of the neck and shaft of the femur. Only 83 cases, treated by various methods, have been reported in the literature. We treated 17 cases at our hospital during the period 1985 to 1991. Our present protocol for this double fracture is treatment with internal fixation as soon as possible. We did not have any bias for any kind of internal fixation devices; we made use of the implants for internal fixation which were most appropriate for that combination of fractures in that individual. In our series we followed the patients for 8 months to 5 years and the fractures united within 3 to 6 months. No major complications occurred, except infection in one case of open fracture. We conclude that both fractures should be fixed internally simultaneously and within 1 week, bearing in mind that individual cases may need special attention.

Adult↗
PubMed1993

Profile of accidents in children.

Out of 5031 children admitted to S.N. Hospital, Agra during one year, there were 716 cases (14.2%) of accidents. Most cases were in the age group of 4-9 years; boys were affected more commonly than girls. The maximum cases occurred due to fall (44.4%), followed by road traffic accidents (26.4%) and burns (11.5%). The consequences in terms of morbidity and mortality was also high. Kerosene oil ingestion was the most common encountered form of poisoning. Incriminating environmental factors could be identified in 51.8% cases and included poorly protected roofs (23.7%), poor state of roads (10.0%), defective vehicles (7.5%), and houses opening directly on the streets (7.3%). More than half of the accidents took place at home (58.7%), followed by those on streets (30.3%) or at farmhouses (57%). Injuries caused by sharp and blunt objects were more common in villages. Only 21.4% children had received first aid, often by the family, before reaching the hospital. The overall mortality rate was 53.1/1000, but in cases of burns the mortality was (146.3/1000). This study suggests that falls and traffic accidents have the highest incidence and mortality in childhood accidents and modification of the home environment can be an effective measure to prevent such incidents.

Accidents↗
PubMed1992

Effect of ascorbic acid and curcumin on quercetin-induced nuclear DNA damage, lipid peroxidation and protein degradation.

The effects of ascorbic acid and curcumin on quercetin-induced DNA damage, lipid peroxidation protein degradation were investigated in a model system of isolated rat-liver nuclei under aerobic conditions and in the presence of equimolar concentrations of iron or copper. Neither ascorbic acid nor curcumin inhibited quercetin-induced nuclear DNA damage, lipid peroxidation, or protein degradation. In fact, both antioxidants stimulated the oxidative damage to nuclear macromolecules. Ascorbic acid significantly increased the quercetin-induced nuclear DNA damage in the presence of either iron or copper. The increases in quercetin-induced nuclear lipid peroxidation and protein degradation by ascorbic acid were statistically significant only in the presence of iron or copper, respectively. Similarly, stimulation of quercetin-induced DNA damage and lipid peroxidation by curcumin was statistically significant only in the presence of copper or iron, respectively. Curcumin had no significant effect on nuclear protein degradation. These results demonstrate the pro-oxidant properties of ascorbic acid and curcumin, compounds that also demonstrate antioxidant and anticarcinogenic properties. Ascorbic acid and curcumin may therefore each have a dual role in carcinogenesis.

Animals↗
PubMed1991

Effects of antioxidants on quercetin-induced nuclear DNA damage and lipid peroxidation.

The effects of catalase, superoxide dismutase, mannitol, glutathione, and diallyl sulfide on quercetin-induced DNA damage and lipid peroxidation were investigated in a model system of isolated rat-liver nuclei under aerobic conditions and in the presence of equimolar iron or copper. Mannitol produced a small but significant inhibition of the concurrent nuclear DNA damage and lipid peroxidation induced by quercetin in the presence of iron or copper. Catalase significantly decreased quercetin-induced nuclear DNA damage only in the presence of iron and had no significant effect on lipid peroxidation. Superoxide dismutase showed no significant effect on nuclear DNA damage, but stimulated the quercetin-induced lipid peroxidation only in the presence of copper. Glutathione significantly inhibited the nuclear lipid peroxidation but enhanced the DNA damage. Diallyl sulfide significantly enhanced the nuclear DNA damage but stimulated the lipid peroxidation only in the presence of iron. These results suggest that the reactive oxygen species, especially the hydroxyl radicals, are responsible for the concurrent lipid peroxidation and DNA damage induced by quercetin in the presence of iron or copper in isolated rat-liver nuclei.

Allyl Compounds↗
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↗