Showing papers by "Banaras Hindu University published in 1997"

Antioxidant activity of glycowithanolides from Withania somnifera.

Abstract: Antioxidant activity of active principles of Withania somnifera, consisting of equimolar concentrations of sitoindosides VII-X and withaferin A, was investigated for their effects on rat brain frontal cortical and striatal concentrations of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX). Results were compared with effects induced by deprenyl, an agent with well documented antioxidant activity. Active glycowithanolides of W. somnifera (WSG) (10 and 20 mg/kg, i.p.), administered once daily for 21 days, induced a dose-related increase in SOD, CAT and GPX activity in frontal cortex and striatum, which was statistically significant on days 14 and 21, except with the lower dose of WSG on GPX activity, where the effect was evident only on day 21. The data were comparable to those induced by deprenyl (2 mg/kg/day, i.p.) with respect to SOD, CAT and GPX activities, which were evident by day 14. These findings are consistent with the therapeutic use of W. somnifera as an Ayurvedic rasayana and medhyarasayana. Antioxidant effect of active principles of W. somnifera may explain, at least in part, the reported antistress, immunomodulatory, cognition-facilitating, anti-inflammatory and anti-aging effects produced by them in experimental animals, and in clinical situations.

Antihyperglycemic activity of phenolics from Pterocarpus marsupium.

Abstract: Glucose levels in rats with hyperglycemia induced by streptozotocin were determined after ip administration of marsupsin (1), pterosupin (2), and pterostilbene (3), three important phenolic constituents of the heartwood of Pterocarpus marsupium. Marsupsin and pterostilbene significantly lowered the blood glucose level of hyperglycemic rats, and the effect was comparable to that of 1,1-dimethylbiguanide (metformin).

Effect of Trasina, an Ayurvedic herbal formulation, on pancreatic islet superoxide dismutase activity in hyperglycaemic rats.

Abstract: Diabetes mellitus was induced in male CF strain rats by streptozotocin (STZ) and hyperglycaemia and superoxide dismutase (SOD) activity of pancreatic islet cells was assessed on days 7, 14, 21 and 28. STZ induced significant hyperglycaemia and a concomitant decrease in islet cell SOD activity. Transina (TR), an Ayurvedic herbal formulation comprising of Withania somnifera, Tinospora cordifolia, Eclipta alba, Ocimum sanctum, Picrorrhiza kurroa and shilajit, had little per se effect on blood sugar concentrations and islet SOD activity in euglycaemic rats, in the doses of 100 and 200 mg/kg, p.o. administered once daily for 28 days. However, these doses of TR induced a dose- related decrease in STZ hyperglycaemia and attenuation of STZ induced decrease in islet SOD activity. The results indicate that the earlier reported anti-hyperglycaemic effect of TR may be due to pancreatic islet free radical scavenging activity, the hyperglycaemic activity of STZ being the consequence of decrease in islet SOD activity leading to the accumulation of degenerative oxidative free radicals in islet beta-cells.

Removal and Recovery of Chromium(VI) from Industrial Waste Water

Abstract: Carbon slurry, generated as a waste material in a naphtha-based ammonia plant of the Fertilizer Corporation of India, Gorakhpur, has been used as an adsorbent for the removal of Cr(VI) from aqueous solution at different experimental conditions. The removal was favoured at low pH, with maximum removal at pH 2·5. The effects of concentration and temperature have also been reported. Batch adsorption kinetics have been described by the Lagergren equation. The applicability of the Langmuir isotherm for the present system has been tested at different temperatures. Thermodynamic parameters indicate the endothermic nature of Cr(VI) adsorption on carbon slurry. Recovery of adsorbed chromium for reuse has also been reported in the present study. © 1997 SCI.

Experimental methods for evaluation of psychotropic agents in rodents: I--Anti-anxiety agents.

Abstract: Rodent models of clinical anxiety are extensively used for evaluating putative anxiolytic activity. In the present review, the available methods which can be utilized by most laboratories, have been discussed. These methods have been categorized as methods involving conditioning techniques and those not involving conditioning. In most cases, the methodology has been briefly discussed in terms of experimental use and efficacy of benzodiazepine and the newer non-benzodiazepine anxiolytics.

Circulating T helper 1 (Th1) cell- and Th2 cell-associated cytokines in Indian patients with visceral leishmaniasis.

Abstract: Sera from 61 Indian patients with visceral leishmaniasis caused by infection with Leishmania donovani were tested for the presence of T helper 1 (Th1) cell-(interferon-gamma [IFN-gamma]) and Th2 cell-associated cytokines (interleukin-4 [IL-4] and IL-10). The IFN-gamma activity was detected in 53%. IL-4 in 84%, and IL-10 in 56% of patient samples. Sera from 10 healthy Indian controls showed detectable IFN-gamma in 90%. IL-4 in 10%, and IL-10 in 20%; corresponding percentages for sera from eight healthy American controls were 100%, 12%, and 0%, respectively. Quantitative data for the 61 patients compared with the 10 Indian controls indicated comparable mean levels of IFN-gamma, but three- and 13-fold increases in IL-10 and IL-4, respectively. Undetectable IFN-gamma activity, observed in 47% of patients, was associated with the presence IL-4 alone or in combination with IL-10 but not with IL-10 alone. In patients who had failed prior therapy (n = 29) compared with previously untreated patients (n = 32). IFN-gamma levels were 67% lower and IL-4 levels were two-fold higher, IL-10 activity was comparable. These results using peripheral blood support the presence of a suppressive Th2 cell-associated immune response in symptomatic Indian kala-azar and point to a possible role for IL-4.

Effect of cadmium on proline accumulation and ribonuclease activity in rice seedlings: role of proline as a possible enzyme protectant

Abstract: When seedlings of two rice (Oryza sativa L) cultivars Ratna and Jaya were raised under 100 and 500 µM cadmium nitrate in the medium, a high proline content was noted in Cd2+ stressed seedlings compared to controls Seedlings grown under 500 µM Cd(NO3)2 maintained increased proline level compared to non-stressed seedlings Kinetic properties of RNase extracted from control grown and Cd2+ stressed seedlings showed a marked alteration in Km due to Cd2+ treatment The RNase isoforms were purified from 15-d-old rice seedlings with a total purification of 2225 fold and 7475 % yield using conventional biochemical techniques Three RNase isoforms, namely I, II and III were eluted from DEAE-Sephacel column The isoform RNase II had Km value of 32 mg(RNA) cm-3 The in vitro osmotic stress created by incorporation of PEG in the enzyme assay medium led to decreased affinity of enzyme towards its substrate with increase in Km This loss in affinity was partially restored by the addition of 1 M proline in the assay medium, suggesting the possible protective role of proline on RNase under osmotic stress

Preparation of aluminium-fly ash particulate composite by powder metallurgy technique

Abstract: Aluminium-fly ash mixtures containing different weight percentages of fly ash were prepared and compacted at pressures from 138–414 MPa. The compacts prepared at 414 MPa were sintered in nitrogen atmosphere at 600, 625 and 645°C, respectively. The time of sintering ranged from 0.5–6 h. The densification parameter and the green densities of the compacts were determined as a function of compacting pressure and fly ash weight per cent. Density, hardness and strength of the sintered compacts were determined as a function of weight per cent of fly ash particles. Volume changes during sintering of green compacts were also evaluated as a function of increasing fly ash weight per cent. Microscopic studies of green and sintered compacts were done to study the effectiveness of sintering. Green and sintered density of the compacts were found to decrease with increasing weight per cents of fly ash. Sintering results in slight decrease in density and increase in volume of green compacts within the range investigated. Strength of the sintered compacts decreased with increasing weight per cent of fly ash under the present experimental conditions; however, the hardness was found to increase slightly up to 10 wt% fly ash, beyond which it decreased.

Anxiogenic action of caffeine: an experimental study in rats.

Abstract: The anxiogenic action of caffeine (10, 25 and 50 mg/kg, i.p.) was investigated in rats and compared with that of yohimbine (2 mg/kg, i.p.). The experimental methods used were the open-field, elevated plus-maze, social interaction and novelty-suppressed feeding latency tests. Caffeine produced a dose-related profile of behavioural changes, which were qualitatively similar to those induced by yohimbine and which indicate an anxiogenic activity in rodents. Thus, both the drugs reduced ambulation and rears, and increased immobility and defaecation in the open-field test. They decreased the number of entries and time spent on the open arms of the elevated-plus maze, reduced social interaction in paired rats and increased the feeding latency in an unfamiliar environment in 48-h food-deprived rats. Lorazepam, a well known benzodiazepine anxiolytic agent, attenuated the anxiogenic effects of caffeine and yohimbine. Subchronic administration of caffeine (50 mg/kg, i.p.) for 21 days, in different groups of animals,...

Antiulcer activity of naturally occurring pyrano-coumarin and isocoumarins and their effect on prostanoid synthesis using human colonic mucosa.

Abstract: Oral administration of bergenin and norbergenin, two isocoumarins, isolated from the leaves and roots of Flueggea microcarpa and luvangetin, a pyranocoumarin isolated from the seeds of Aegle marmelos Correa, showed significant protection against pylorus-ligated and aspirin-induced gastric ulcers in rats and cold restraint stress-induced gastric ulcers in rats and guinea pigs. The study on prostaglandins release by human colonic mucosal incubates, indicated a concentration-dependent (1-10 micrograms/ml) stimulatory effect of bergenin and norbergenin, while luvangetin (1-10 micrograms/ml) did not produce any effect. The results suggest that gastroprotective effects of bergenin and norbergenin could be due to increased prostaglandin production while, some other mucosal defensive factors may be involved for luvangetin.

Transformed ratio type estimators for the population mean in the presence of nonresponse

Abstract: In this paper we have proposed two transformed ratio type estimators for the populaion mean in presence of non-response. The proporties of these estimators are studied in the case of a Unite population and also through the superpopulation model Approach.

Some FRW models with variable G and

Abstract: Einstein's field equations with G and both varying with time are considered in the context of general homogeneous, isotropic universes in a way which conserves the energy momentum tensor of the matter content. It is found that the solutions of the field equations, which are based on the variation of as but with different constants of proportionality, describe significantly different cosmological scenarios. It is also found that the non-static models with constant density having a vacuum-like equation of state are endowed with inflation for a wide class of functions G(t) and and a static universe with constant density without the vacuum-like equation of state, can exist only for k = 1 with constant G and .

Short-course, low-dose amphotericin B lipid complex therapy for visceral leishmaniasis unresponsive to antimony.

Abstract: Background: Visceral leishmaniasis (kala-azar) is a world-wide, disseminated intracellular protozoal infection for which prolonged, conventional therapy with pentavalent antimony has become increas...

Chronic typhoid carriage and carcinoma of the gallbladder

Abstract: Chronic microbial infections and/or their carrier state have been reported to be associated with particular cancers. Since typhoid infections and carcinoma of the gallbladder (the site where salmonella usually persists) are endemic in northern India, it was considered important to explore the relationship between the two. In the present study, a total of 1001 bile specimens collected from cases of carcinoma of the gallbladder (28), cholelithiasis (56) and individuals without biliary pathology (17) were subjected to aerobic cultures that had been enriched for salmonella. Salmonella typhi and S. paratyphi-A could be detected in a significantly higher (P < 0.05) number in patients with carcinoma of the gallbladder as compared with cholelithiasis and control groups. The existence of such an association indicates that detection and eradication of typhoid carriers may lead to a decrease in the incidence of carcinoma of the gallbladder along with typhoid fever.

Rubiadin, a new antioxidant from Rubia cordifolia.

Abstract: Rubiadin, a dihydroxy anthraquinone, isolated from alcoholic extract of Rubia cordifolia, possesses potent antioxidant property. It prevents lipid peroxidation induced by FeSO4 and t-butylhydroperoxide (t-BHP) in a dose dependent manner. The per cent inhibition was more in the case of Fe2+ induced lipid peroxidation. The antioxidant property of the preparation has been found to be better than that of EDTA, Tris, mannitol, Vitamin E and p-benzoquinone.

Effect of Ti additions on the electrical resistivity of copper

Abstract: Electrical resistivity of Cu Ti alloys containing 1.5, 2.7, 4.5 and 5.4 wt.% Ti, has been determined from the resistance values measured using Kelvins Bridge apparatus at room temperature. The resistivity in solution-treated alloys increases with Ti content linearly up to about 4.0 wt.% Ti, beyond which it decreases with further additions of Ti. However, in peak-aged condition, the resistivity continues to increase linearly up to 5.4 wt.% Ti without showing any decrease. Nordheim's rule of resistivity is followed up to approximately 4.0 wt.% Ti in the solution-treated alloys. Further, Nordheim's rule modified with the incorporation of the law of mixtures for two-phase systems ( ρ t = ρ m ν fm + ρ p ν fp ) is obeyed right up to 5.4 wt.% Ti in the peak-aged alloys. The difference in behaviour is attributed to the fine scale precipitation formed during quenching in solution-treated Cu—4.5Ti and Cu—5.4Ti alloys, as revealed by transmission electron microscopy (TEM). The contribution to the total resistivity by β ′-Cu 4 Ti precipitate and prior cold deformation is considerable in deformed and peak-aged Cu Ti alloys.

Effect of soil nitrogen, carbon and moisture on methane uptake by dry tropical forest soils

Abstract: Methane uptake was measured for two consecutive years for four forest and one savanna sites in a seasonally dry tropical region of India. The soils were nutrient-poor and well drained. These sites differed in vegetational cover and physico-chemical features of the soil. There were significant differences in CH4 consumption rates during the two years (mean 0.43 and 0.49 mg m-2 h-1), and at different sites (mean 0.36 to 0.57 mg m-2 h-1). The mean uptake rate was higher (P < 0.05) in dry seasons than in the rainy season at all the sites. There was a significant season and site interaction, indicating that the effect of different seasons differed across the sites. There was a positive relation between soil moisture and CH4 uptake rates during summer (the driest period) and a negative relation during the rest of the year. The results suggested that seasonally dry tropical forests are a strong sink for CH4, and C and N status of soils regulates the strength of the sink in the long term.

Probabilistic Assessment of Earthquake Hazards in the North-East Indian Peninsula and Hindukush Regions

Abstract: The Himalayan region is one of the most seismic prone areas of the world. The North-East (NE) Indian peninsula and the Hindukush regions mark the zone of collision of the Indian and Eurasian plates. The probability of the occurrence of great earthquakes with magnitude greater than 7.0 during a specified interval of time has been estimated on the basis of four probabilistic models, namely, Weibull, Gamma, Lognormal and Exponential for the NE Indian peninsula and Hindukush regions. The model parameters have been estimated by the method of Maximum Likelihood Estimates (MLE) and the Method of Moments (MOM). The cumulative probability is estimated for a period of 40 years from 1964 and is ranging between 0.881 to 0.995 by the year 1995, using all four models for the NE Indian peninsula. The conditional probability is also estimated and it is concluded that the NE Indian peninsula would expect a great earthquake at any time in the remaining years of the present century. For the Hindukush region, the cumulative probability has already crossed its highest value, but no earthquake of magnitude greater than 7.0 has occurred after 1974 in this area. It may attribute to the occurrence of frequent shocks of moderate size, as seventeen earthquakes of magnitude greater than 6.0, including four greater than 6.4, have been reported until 1994 from this region.

Testimator of the scale parameter of the exponential distribution using linex loss function

Abstract: The present paper investigates the properties of a testimator of scale of an exponential distribution under Linex loss function. The risk function of testimator is derived and compared with that of an admissible estimator relative to Linex loss function. The shrinkage testimator is proposed which is the extension of testimator and its properties have been discussed. The level of significance of testimator is decided on the basis of Akaike information criterion following Hirano (1977, 1978). It is found that the testimator and shrinkage testimator dominates the admissible estimator in terms of risk in certain parametric space.

Preparation and characterization of barium stannate BaSnO3

Abstract: Stannates have received much attention in recent years as components of ceramic dielectric bodies [1, 2]. Stannates of the general formula MSnO3, where M Ca, Sr or Ba, form a component of dielectric materials used for thermally stable capacitors [3, 4]. Barium stannate has found increasing applications in dielectric devices as a constituent of complex pervoskite solid solutions. Wainer [5, 6] disclosed devices comprised of the alkaline earth stannates and alkaline earth titanates in a series of patents. Recently it has been reported that thin films of BaSnO3 can be used for sensing nitrogen oxide and carbon monoxide gases [7, 8]. Unlike alkaline earth titanates MTiO3 (M Sr, Ca, Ba and Pb), these stannates have not been studied extensively in pure and doped form. For the last few years, we have been synthesizing and characterizing these stannates in doped and undoped forms [9‐13]. The results of these investigations prompted us to synthesize and characterize undoped BaSnO3. Barium stannate was prepared by the solid state ceramic route, using BaCO3 and SnO2 having purity 99.5% and 99.99%, respectively. Stoichiometric amounts of BaCO3 and SnO2 were mixed in a ball mill for 6 h using acetone as the mixing media. The mixed powder was dried in an oven overnight. The dry mixed powder was calcined in a platinum crucible at 1475 K for 6 h in air. The calcined powder was ground, mixed and pelletized (a die of 12 mm diameter was used for 2‐3 mm thick pellets) at various loads starting from 30 kN to 70 kN at intervals of 10 kN load. This was done to obtain an optimum load for the maximum green density. The

Production of Alkaline Protease by Bacillus thuringiensis H 14 in Aqueous Two‐Phase Systems

Abstract: Alkaline protease production by Bacillus thuringiensis H 14 was studied in aqueous two-phase systems composed of PEG X (X = 9000, 6000, 4000) and potassium phosphate. The top phase is continuous and rich in PEG while the bottom phase is dispersed and is rich in phosphate, microbial cells being mainly retained in the bottom phase. The alkaline protease produced during fermentation, partitioned into the upper phase (about 80%) and total protease produced were about 2·80 and 2·26 times higher than that of homogeneous fermentation when the fermentations were carried out in aqueous two-phase systems from the beginning and made after 45 h of inoculation respectively. © 1997 SCI.

Effect of prior cold work on mechanical properties and structure of an age-hardened Cu–1.5wt% Ti alloy

Abstract: The effects of prior cold work on hardness, tensile properties, electrical conductivity and microstructure of an aged Cu–1.5 wt% Ti alloy have been studied by employing hardness and resistivity measurements, tensile tests and scanning and transmission electron microscopy. The hardness increased from 80 VHN in the solution-treated condition, to 210 VHN on peak ageing and 280 VHN with prior cold work followed by ageing. While a similar trend has been observed in yield and tensile strengths, the ductility (percentage elongation) decreased from 45% to 9%. The electrical conductivity of the alloy also increased up to 26% International annealed copper standard upon ageing the cold-worked alloy. Maximum strengthening of the alloy was associated with the precipitation of metastable, coherent and ordered Cu4 Ti, β′ phase having body-centred tetragonal structure. The differences in the properties and microstructural evolution between low and high titanium alloys (for example, the absence of composition modulations and deformation twins in Cu–1.5 Ti alloy, while they are present in Cu–4.5 Ti alloy) have been discussed. Prior cold work did not change the fracture mode of microvoid coalescence.

Reaction history of sapphirine granulites and a decompressional P-T path in a granulite complex from the Eastern Ghats

Abstract: The sapphirine granulites from G. Madugula, Eastern Ghats preserve a variety of mineral textures and reactions. Corona and reaction textures are used in conjunction with mineral compositions to construct a sequence of metamorphic reactions describing the mineralogical evolution of sapphirine granulites. An early stage is characterized by the development of sapphirine + quartz, spinel + quartz in textural equilibrium, and possible relicts after osumilite during peak metamorphic conditions. Sapphirine/spinel crystals were later detached from quartz in the form of mineral coronas. During a subsequent sapphirine-cordierite stage, several cordierite forming reactions reflect decreasingP-T conditions. Finally during the late stage, a few samples show evidence of retrogressive hydration. Sapphirine is rather iron-rich (12.8 wt%) and the Mg number in the analysed minerals varies in the order: cordierite > phlogopite > sapphirine > orthopyroxene > spinel > garnet.P-T conditions of metamorphism have been constrained through the application of geothermobarometry and thermodynamically calibrated MAS equilibria.P-T vectors from granulite facies rocks in the G. Madugula area indicate that the rocks experienced substantial decompression (up to 3 kbar) and moderate cooling (150–200°C) subsequent to peak conditions of metamorphism (8.4 kbar, > 900°C). The decompressionalP-T history of sapphirine granulites interpreted from textural features and thermobarometric estimates suggest that they may have eventually resulted from exhumation of thickened crust.