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Biomedical subjects

A Saha

Publications and source records attributed to A Saha.

135 records · Page 8Linked to original sources
PubMedDate not supplied

Effects of oral contraceptive norethindrone on blood-lipid and lipid peroxidation parameters.

Considering importance of the lipophilicity of norethindrone (log P=2.97), a significant contributor to its mechanism of action, interaction of the drug with total lipids of goat whole blood have been investigated using phospholipid binding, fatty acid composition and peroxidation phenomena as the parameters under investigation. The objective was to derive an insight into the pharmacodynamic behavior of the drug by correlating biological activity with drug induced changes in lipid constituents. Significant loss in phospholipid along with changes in fatty acid cotmposition was observed after incubation of whole blood with norethindrone at 56 ng/ml (effective contraceptive concentration in blood) in varying periods of time. This may be ascribed to binding affinity of norethindrone with lipid constituents in blood. Lipid binding potential of the drug may have a role in its therapeutic effect. Lipid peroxidation induction potential of norethindrone was quantitatively measured in the context of its toxicity. The results reveal that northindrone caused significant extent of lipid peroxidation. Ascorbic acid, a promising antioxidant, at equivalent human dose levels of 250 mg and 500 mg could significantly reduce norethindrone induced lipid peroxidation.

Animals↗
PubMedDate not supplied

Thrombosis as a complication of extended stay at high altitude.

BACKGROUND: There is limited knowledge about the medical problems of long term stay at high (> 3000 m) and extreme (> 5000 m) altitudes, as these areas are generally considered uninhabitable. METHODS: Prospectively collected clinical records of all patients hospitalized at Command Hospital, Western Command between November 1998 and February 2000 were reviewed to identify thrombotic complications among patients from high and extreme altitude areas as well as those from non-high altitude areas who were < 45 years of age. RESULTS: Of 20,257 hospital admissions during the study period, 1692 were from high and extreme altitude areas. Forty-six patients from these areas had thrombosis-related diseases compared to 17 from non-high altitude areas (odds ratio: 30.49; 95% CI: 17.06-51.67; p < 0.001). The mean (SD) age of all patients with thrombotic complications was 32 (8) years and all were men. The mean duration of stay at high and extreme altitudes of such patients was 10.2 (5.6) months. Only 25 were smokers (mean 5.2 pack-years) and 39 consumed alcohol (mean 54 ml/day). Apart from frostbite in 5, no other medical condition was noted in these patients. The vascular events were deep vein thrombosis (20), pulmonary thromboembolism (6), stroke (15), thrombosis of the abdominal veins (8), and retinal artery and peripheral arterial thrombosis (1 each). The presenting complaint in all patients with thrombosis of the abdominal veins was poorly localized pain in the upper abdomen followed by ascites (6/8). Five of these patients also had a large spontaneous splenic haematoma. None of the patients investigated was found to have a procoagulant disorder. CONCLUSION: Long term stay at high and extreme altitudes is associated with a 30 times higher risk of spontaneous vascular thrombosis. Veins are common sites of such thrombotic events. We also encountered thrombosis of the portal, splenic and superior mesenteric veins in our patients who had stayed at high and extreme altitudes.

Adult↗
PubMedDate not supplied

Massive lower intestinal bleeding--a decade of experience.

BACKGROUND: Lower gastrointestinal bleeding is defined as hemorrhage orginating distal to the ligament of Treitz. Its diagnosis is difficult, often requiring endoscopy, angiography and isotope scans. METHODS: All patients with massive lower gastrointestinal bleeding seen in three gastroenterology centers of Armed Forces during an 11 year period between 1988 and 1999 were retrospectively analysed. RESULTS: A total of 91 patients with massive lower gastro intestinal bleeding were seen during 11 years. The mean age of the patients was 38.9 years and 64 were males. Aetiological diagnosis was: Non-specific ulcers--11, Ileal tuberculosis--8, NSAID enteropathy--8, Enteric fever--7, Meckel's diverticulum--7, Polyps--6, Ulcerative colitis--5, Carcinoma colon--5, Colonic diverticulosis--5, No cause found--5, Polyposis coli--5, Jejunal diverticulae--3, Angiodysplasia colon--3, Radiation colitis--3, Ischaemic colitis--3, Ileal tumor--2, Ileal angiodysplasia--2, Intestinal Lymphoma--2, Bechet's syndrome--1. Bleeding stopped on conservative therapy in 18 patients (including 5 where no diagnosis could be made). Diagnosis was made in 36 patients on fiber-optic colonoscopy done during active bleeding. Remaining patients were subjected to emergency laparotomy and diagnosis was obvious on inspection of abdominal contents in 25 cases. The diagnosis was finally made in remaining 12 cases by intraoperative endoscopic examination through an ileotomy. Four patients died, only one of them due to rebleed after surgery from an additional lesion. CONCLUSIONS: Compared with experience in Western countries, massive lower gastro-intestinal hemorrhage in India affects younger patients, has different causes and carries a lower mortality. Colonoscopy is useful in making diagnosis during active lower intestinal bleeding in about one-third cases. Exploratory laparotomy and Intra-operative endoscopy are complimentary to above examination and can make the diagnosis in most of the remaining cases.

Adolescent↗
PubMedDate not supplied

Portal system thrombosis: a complication of long-term residence at extreme altitude.

BACKGROUND: With induction of the Indian Army to heights over 5,000 meters above sea level, complications of long-term stay at extreme altitude have come to light. We describe our experience with patients developing portal system thrombosis. METHODS: Clinical data were collected over 2 years on patients hospitalized for thrombotic complications from high-altitude (HAA) and non-high altitude (non-HAA) areas. Site of thrombosis was confirmed by imaging or at surgery. Patients were investigated for conditions that predispose to venous thrombosis. RESULTS: Ten cases of portal system thrombosis were seen during the period; of these, 9 (mean age 28 [SD 3.9] years; all men) were from HAA. Mean duration of residence in HAA was 12.4 (4.9) months; two were smokers and six drank 7-22 g alcohol/day at least 5 times a week. The first symptom was abdominal pain; this was later complicated by gastrointestinal bleeding (n=5), fever (7), vomiting (7), and weight loss (5). Average time between onset of first symptom and reaching a tertiary-care hospital was 9.5 (4.7) days. Clinical examination showed ascites (8 cases), splenomegaly (7), and hepatomegaly (6). Mean hemoglobin level at admission was 15.8 (3.4) g/dL. Ascites was hemorrhagic; five cases also had large splenic hematoma. The site of thrombosis was splenic vein (7 cases), portal vein (6), and superior (4) and inferior (1) mesenteric vein. None of 5 patients investigated had any prothrombotic condition. Endoscopic/ sonographic evidence of development of collaterals appeared as early as 12-20 days after onset of symptoms. CONCLUSION: Residence in HAA for extended periods is a risk factor for development of portal system thrombosis. Persistent pain in abdomen in such individuals should raise the possibility of portal system thrombosis.

Adult↗
PubMedDate not supplied

Evaluation of alpha-tocopherol, probucol and ascorbic acid as suppressors of digoxin induced lipid peroxidation.

Protective effects of three free radical scavengers, tocopherol (TOC), probucol (PR) and ascorbic acid (AA), on cardiotonic glycoside digoxin (DIG) induced lipid peroxidation in goat liver homogenate, have been studied by measuring malondialdehyde and glutathione contents as indicator parameters. The level of reduced glutathione decreased vis-a-vis malondialdehyde content increased in the drug treated samples in comparison with the controls. This suggests that DIG may have significant lipid peroxidation induction capacity. Considering lipid peroxidation as a toxicity mediating process, this may be related to the toxic potential of the drug. When the liver homogenate samples were incubated with antioxidant (TOC/PR/AA) in conjunction with the drug (DIG), lipid peroxidation was suppressed as indicated by increased level of reduced glutathione and decreased level of malondialdehyde in comparison with those of drug treated samples. This indicates that TOC, PR and AA may have considerable suppressive action on DIG induced lipid peroxidation. Thus, these antioxidants merit further extensive study to explore their potential in reducing DIG induced toxicity that may be mediated by free radical mediated process.

Animals↗
PubMedDate not supplied

Exploring effects of different antioxidants on dexamethasone-induced lipid peroxidation using common laboratory markers.

As a part of our ongoing effort to explore drug-induced lipid peroxidation in relation to drug-induced toxicity, our recent observations on lipid peroxidation induction potential of dexamethasone, a commonly used glucocorticoid compound in inflammatory and allergic conditions, has been presented considering lipid peroxidation a possible mediator of toxicity. An attempt was made to see the suppressive actions of some conventional antioxidant compounds, viz, ascorbic acid, alpha-tocopherol and probucol on dexamethasone-induced lipid peroxidation. It was found from the study that dexamethasone increased malondialdehyde content vis-a-vas decreased the level of reduced glutathione significantly in the liver homogenate. This suggests that dexamethasone caused a significant extent of lipid peroxidation which may be related to the toxic potential of the drug. It was further found all of the above antioxidants could suppress dexamethasone-induced lipid peroxidation to the significant extent.

Animals↗