Uptake and translocation of selenium by maize (Zea mays) from its environmentaly important forms.

Pot culture studies were conducted to examine the effect of selenite (SeO3(2-)) and selenate (SeO4(2-)) on the uptake and translocation of root absorbed selenium in maize Zea mays plants grown in sand and soil culture. Increasing selenium supplementation (0.5-6.00 microg/ml), increased the selenium retention in roots, but there was little transfer of selenium from shoot to grains. The study indicates that selenite species (less mobile) also accumulates in maize plants when supplied in solution form. Selenium does not cause any adverse effect on the maize plants (dry matter yield vs concentration, no significant correlation, p>0.05).

Small mammal trapping in tropical montane forests of the upper Nilgiris, southern India: an evaluation of capture-recapture models in estimating abundance.

Capture-mark-recapture was used to study small mammal populations in tropical montane forests in southern India. Eleven plots in six montane forest patches were sampled from February-October, 1994. Six species were captured, including four rodents and two shrews. PROGRAM CAPTURE was used to derive estimates of density of the most abundant species in the study area, Rattus rattus Linnaeus. The coefficient of variation of the density estimate was used as an index of precision. The coefficient of variation decreased exponentially with increasing capture probability and with an increase in trapping duration. The coefficient of variation and the capture probability were not correlated with estimates of density. The density estimate increased with trapping duration, as did trap mortality. The latter may have been due to the trend of increased mortality with recaptures of the same individual, which in turn may have been due to weight loss over consecutive captures. Estimates of density derived using four estimators were different for 2, 3, 4 and 5 days of trapping. The coefficient of variation was highest for the generalized removal estimate and lowest for Darroch's estimate. The models and estimators could not be applied to more than one species, and for this species, only in select habitats in a few seasons. Therefore, models of density estimation developed for temperate areas may not be suitable for tropical habitats due to low densities of small mammals in these habitats.

Hepato protective effect of Liv-52 against CCl4 induced lipid peroxidation in liver of rats.

Effect of oral feeding of Liv-52, on lipid peroxidation in normal liver and damaged liver induced by CCl4 of albino rats was studied. While Liv-52 did not show any effect on normal healthy liver cells, it had a significant protective effect against damage by CCl4 as shown by significant decrease in malonaldialdehyde content.

Serotonergic mechanisms in heart failure.

A total of 29 subjects were studied which included 18 heart failure and 11 matched control cases. The underlying heart disease in heart failure cases was mostly chronic rheumatic valvular disease. The diagnosis of heart disease and heart failure was made on the basis of clinical examination, supplemented by electrocardiography, chest skiagram and echo cardiography. The serotonin status was assessed by measuring platelet serotonin uptake, intraplatelet serotonin content and whole blood 5-hydroxytryptamine (5-HT) levels. Blood platelet count was also done. In heart failure cases, platelet count were significantly less, the platelet 5-HT uptake and blood 5-HT levels remain unaltered. These findings indicate that platelet pool of serotonin does not contribute to raised serotonin blood levels in heart failure. The high blood serotonin levels may be due to either clearance defect or enhanced secretion from the gut or both. The altered serotonin kinetics in platelets also indicate a state of platelet activation in heart failure.

Platelet norepinephrine efflux in thrombotic stroke.

Twenty CT proven patients of thrombotic stroke who were non-diabetic, non-hypertensive and non-hyperlipidemic were evaluated in acute phase (within 7 days of onset of neurological deficit) for platelet count and spontaneous platelet norepinephrine (NE) efflux, measured as the fraction (of initial total content) of 3H-NE released from platelets in 30 and 60 min. NE efflux was significantly greater (P less than 0.001) in stroke patients (34.09 +/- 4.92% at 30 min and 50.45 +/- 7.1% at 60 min) as compared to controls (23.27 +/- 4.16% at 30 min and 39.49 +/- 3.27% at 60 min). This excessive efflux may result in increased concentrations of NE in local plasma, which by causing enhanced platelet aggregation and damage to vascular endothelium and vasospasm, may contribute towards the development and progression of cerebral thrombosis.

Antiparkinsonian activity and dopamine receptor binding studies of imidazolone derivatives.

Mannich bases and styryl derivatives of imidazolones were evaluated for their antiparkinsonian activity. Two compounds showed potent antiparkinsonian activity. These active compounds also showed binding with dopamine receptors in striatal membrane preparation of rat brain.

Platelet ionic calcium and serum total calcium in essential hypertension.

A total of 44 cases comprising hypertensive (31) and normotensive group (13) were studied. Serum total calcium concentrations remained unaltered in hypertensives. Platelet cytosolic calcium in hypertensive group was significantly higher as compared to the normotensive controls. Platelet cytosolic calcium correlated with systolic and diastolic blood pressure and mean arterial pressure significantly.

Platelet serotonergic mechanisms and glomerulonephritis.

Proven cases (28) of glomerulonephritis (GN) were evaluated for clinico-biochemical profile, bleeding time, platelet count, platelet aggregation and platelet serotonergic mechanisms. Inordinate increase in platelet aggregation and altered platelet serotonergic mechanisms (reduced 5-HT, uptake, reduced intraplatelet 5-HT and increased plasma 5-HT) were demonstrated in some histopathological types of GN. The mechanisms and importance of these alterations have been discussed.