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Biomedical subjects

O Kumar

Publications and source records attributed to O Kumar.

9 recordsLinked to original sources

Oxidative stress associated hepatic and renal toxicity induced by ricin in mice.

Ricin a glycoprotein from the Ricinus communis seeds, is known to have diverse toxic effects on cells of different visceral organs. We have studied the hepatotoxicity, nephrotoxicity, and oxidative stress following i.p. administration of ricin (25 microg/kg) in Swiss albino male mice. The results of this study revealed that activities of various enzymes like glutamic pyruvic transaminase (GPT), alkaline phosphatase (ALP), gamma glutamyl transpeptidase (gamma-GT), and lactate dehydrogenase (LDH) were increased in plasma, liver, and kidney tissues indicating damage in liver and kidney. Blood urea level was also increased. However, blood creatinine and bilirubin were not altered. Lipid peroxidation increased to 49 and 25% in hepatic and renal tissue. Total non-protein sulfhydryl content decreased in plasma (12%), hepatic (29%), and renal (16%) tissues. Superoxide dismutase activity decreased significantly in liver (43%) and kidney (37%). The activity of glutatione peroxidase was also decreased. The decrease was more prominent in kidney than liver. A significant increase, 20 to 27% in the activity of catalase was observed in plasma, liver, and kidney. These results indicate that ricin produces hepatoxicity, nephrotoxicity, and oxidative damage at 24 h of post treatment. The hepatotoxicity was more prominent than nephrotoxicity.

Animals↗

Protective effect of various antioxidants on the toxicity of sulphur mustard administered to mice by inhalation or percutaneous routes.

Protective effect of various antioxidants, trolox (water soluble analogue of vitamin E), quercetin (bioflavonoid) and glutathione reduced (GSH), was studied following sulphur mustard (SM) intoxication. SM, a blistering agent was administered to Swiss albino female mice through inhalation (1 LC50=42.3 mg/m3 for 1 h duration; 14 days observation for mortality) and percutaneous (1 LD50=154.7 mg/kg; 7 days observation for mortality) routes. The antioxidants were administered three times at the dose of trolox, 500 microg/kg; quercetin, 5 mg/kg and GSH, 400 mg/kg body weight by intraperitoneal injection, one immediately following SM exposure, then once each day for 2 days after SM treatment. The effect of antioxidants on survival, markers of oxidative damage and purine metabolites was investigated. Survival study animals were observed for 14 days. Oxidative markers (in blood, liver and lung) and purine metabolites (in blood and urine) were investigated 72 h after SM treatment. Survival time increased significantly following trolox and quercetin treatments through the inhalation route. Significant decrease in GSH and increase in the level of malondialdehyde (MDA) indicated oxidative damage to liver and lung tissues following SM inhalation and percutaneous exposure. Blood and urinary uric acid, end product of purine metabolism showed an increased following both routes of exposures. The antioxidants, trolox and quercetin protected the liver and lung tissues from oxidative damage caused by SM exposure through inhalation and percutaneous routes. This study showed that antioxidants could enhance survival time, protect liver and lung from oxidative damage and reduce accumulation of purine metabolites in blood following SM intoxication.

Administration, Cutaneous↗

Covert bacteriuria in nephrotic syndrome.

Prevalence of covert bacteriuria in patients of nephrotic syndrome admitted for kidney biopsy was studied in 205 patients. Age ranged from 10 years to 65 years. 148 patients were male and 57 were female. Prevalence of covert bacteriuria was found in 38 patients (18.53%). In bacteriuric patients 30 were male, 8 were female. Escherichia coli was the commonest organism grown in bacteriuric patients (30 or 78.9%). Serum albumin was low and 24-hour urinary protein excretion was high in bacteriuric patients in comparison to abacteriuric patients. In bacteriuric patients membranous nephropathy was the commonest histopathological finding present in 15 patients (39.47%).

Adolescent↗

Subacute (90 days) oral toxicity studies of Kombucha tea.

Kombucha tea (KT) is a popular health beverage and is used as an alternative therapy. KT is prepared by placing the kombucha culture in solution of tea and sugar and allowing to ferment. The inoculum is a fungus consisting of symbiotic colony of yeast and bacteria. KT is consumed in several countries and is believed to have prophylactic and therapeutic benefits in a wide variety of ailments, viz., intestinal disorders, arthritis, ageing and stimulation of immunological system. Though KT is used in several parts of the world its beneficial effects and adverse effects have not been scientifically evaluated. Since there are no animal toxicological data on KT, subacute oral toxicity study was carried out. Five groups of rats were maintained: (a) control group given tap water orally, (b) KT given 2 ml/kg orally, (c) plain tea (PT) given 2 ml/kg orally, (d) KT given in drinking water, 1% (v/v) and (e) PT given in drinking water, 1% (v/v). The rats were given this treatment daily for a period of 90 days. Weekly records of weight, feed intake, water intake and general behaviour were monitored. There was no significant difference in the growth of the animals as evidenced by the progressive body weight change. The organ to body weight ratio and histological evaluation did not show any toxic signs. The haematological and biochemical variables were within the clinical limits. The study indicates that rats fed KT for 90 days showed no toxic effects.

Administration, Oral↗

Acute renal failure in the elderly: a demographic and clinical study of patients in eastern India.

A total of 638 patients with acute renal failure (ARF) of diverse etiology were studied over a period of 9 years (July 1985-Dec, 1994) of which 96 (15%) patients were classified as elderly ARF with mean age of 72.5 years. Medical causes accounted for 80% of geriatric ARF while 20% patients, had ARF of surgical origin. Decreased renal perfusion resulting from gastroenteritis was the predominant (52.8%) cause of ARF in the medical group. Nephrotoxic ARF and ARF due to F. malaria were seen in 10 and 7 patients respectively. Obstructive uropathy was observed in 12 patients in surgical group and in remaining 8 patients ARF developed following various surgical procedures. ARF in association with multiorgan failure was not observed in our study. Mortality was seen in 24 patients (25%). The causes of mortality were GI bleed (6), peripheral circulatory failure (5), hyperkalemia (4) and sepsis (4). Thus medical ARF remains the major cause of acute renal failure in elderly patients in our study in contrast to ARF associated with multiorgan failure and surgery in developed countries.

Acute Kidney Injury↗

Acute renal failure in falciparum malaria--increasing prevalence in some areas of India--a need for awareness.

Twenty-six cases (4.8%) from a total of 540 patients with acute renal failure (ARF) of diverse aetiology had ARF in association with falciparum malaria. Their ages ranged from 15 to 85 years (mean 31.2). Urinary sediment abnormalities and proteinuria (less than 1 g/24 h) were observed in 15 (57.7%) cases. The probable underlying factors leading to ARF were: volume depletion 17 (65.3%), intravascular haemolysis 8 (30.8%), hyperparasitaemia 8 (30.8%), cholestatic jaundice 6 (23%), and hypotension 5 (19.2%). Dialysis therapy was required in 15 patients (57.7%) as they had severe renal failure, and the remaining 11 patients improved with supportive measures. All patients received antimalarial therapy. The clinical course of ARF was consistent with acute tubular necrosis in 20 patients. Six cases were subjected to percutaneous renal biopsy. One patient showed histological features of necrotizing glomerulonephritis along with acute tubulointerstitial nephritis. The biopsies in the other five patients showed features of acute tubular necrosis in three, and acute interstitial oedema with patchy tubular necrosis in two. The mortality rate was 30.8%. Thus falciparum malaria, which has been an important cause of ARF in certain highly endemic zones of India, is showing an increasing prevalence in other parts such as Eastern Uttar Pradesh due to an imbalance between the increasing population and inadequate sanitary facilities, which further worsen during floods.

Acute Kidney Injury↗

Acute renal failure in eastern India.

The present study included 426 patients with acute renal failure age range 7 months to 85 years, during 8-year period (1984-1992). Medical, surgical and obstetric causes were responsible for ARF in 68.3, 17.8, and 14% of cases respectively. The main aetiological factors encountered were volume depletion secondary to gastrointestinal fluid loss (35.2%), acute glomerulonephritis (10.3%), nephrotoxin (8.6%), falciparum malaria (4.2%), obstructive uropathy (13%), post-abortal (10.5%), and miscellaneous factors (1.4%) of patients. The overall mortality was 19.2%. Thus our observation revealed that diarrhoeal diseases (35.2%), obstructive uropathy (13.3%), and septic abortion (10.5%) were the main causes for ARF in medical, surgical, and obstetric groups respectively. In contrast to our studies, acute renal failure associated with diarrhoeal diseases, septicaemia, falciparum malaria and septic abortion are rare in European countries.

Acute Kidney Injury↗

Use of dexamethasone in treatment of insulin lipoatrophy.

To treat insulin lipoatrophy, small amounts of dexamethasone (4 micrograms/unit) were added to insulin injections in nine patients. Six cases showed significant improvement of dexamethasone-treated sites over that of control sites in six months. With the continued use of dexamethasone-containing insulin, they remained mostly free of atrophic areas during the follow-up period of over two years. Our experience suggests the usefulness of this therapy.

Adipose Tissue↗

Effect of sulphur mustard inhalation exposure on some urinary variables in mice.

The effect of sulphur mustard (2,2'-dichlorodiethyl sulphide) exposure through inhalation at 0.5. 1.0 and 2.0 LC50 (21.2, 42.3 and 84.6 mg m(-3) for 1 h) on some urinary variables was studied in female mice at 6, 24 and 48 h and 7 days post-exposure. The urinary excretion and circulatory blood accumulation of uric acid increased significantly. The level of creatine was also elevated significantly as compared to the control at 2 LC50. It is concluded that sulphur mustard alkylates DNA and triggers catabolism of apurinated purine bases in a very short time. The increase in uric acid excretion in urine can be detected only when the exposure concentration is high.

Administration, Inhalation↗