Search PubMed⌕ Search

Biomedical subjects

P Bhattacharyya

Publications and source records attributed to P Bhattacharyya.

At least 19 recordsLinked to original sources
PubMed2004

Effect of arsenic contamination on microbial biomass and its activities in arsenic contaminated soils of Gangetic West Bengal, India.

A study was conducted to see the effect of arsenic contamination on soil quality indicators, viz., microbial biomass, soil respiration, fluorescein diacetate and dehydrogenase (DHG) activity in arsenic contaminated soils of West Bengal. All the parameters were significantly and negatively correlated with all the form of arsenic (bioavailable and total) but the microbial metabolic quotient was significantly and positively correlated with all forms of arsenic, indicating arsenic induced stress to the soil microbial community. This may be due to part of the microbial biomass, which is located in the inner parts of the micro-aggregates of soil, which is affected by arsenic accumulates present in soil particles. Linear regression analysis revealed that the bioavailable arsenic exerted greater inhibitory effect on the soil microbial population than the total arsenic content of soils. Water-soluble arsenic showed more inhibitory effect than NaHCO(3) extractable form, in their association with biological properties of the contaminated soils. Water-soluble form of arsenic was much more toxic than insoluble forms. This signified that with increase in bioavailability, the arsenic exerted more inhibitory effect on these parameters. It is thus suggested that the microbial biomass, fluorescein diacetate and dehydrogenase activity alone and expressed on a soil organic matter basis along with the soil respiration parameters can be helpful in assessing the effects of arsenic on the size and activity of microbial biomass in soils.

Arsenic↗
PubMed2004

Heavy metal levels and esterase variations between metal-exposed and unexposed duckweed Lemna minor: field and laboratory studies.

Environmental homogeneity is being continuously disturbed and affected by artificially introduced loads of chemical toxicants that also include heavy metals. The Tiljala wetlands of the eastern fringe of Calcutta, West Bengal (India) are a virtual sink for the deposition of urban and industrial wastes that get admixed with the aquatic environment. We have selected Lemna minor (duckweed), as a representative of the biota surviving therein for the present study. Concentrations of lead, cadmium, chromium, zinc, copper and mercury in the fronds of Lemna were measured to peep into the range of input of heavy metals in the duckweed subjects. Natural unexposed population of duckweed from a domestic pond in Batanagar area, 24 Parganas, West Bengal (India) was also found to accumulate similar concentrations of these metals when cultured in artificially contaminated water in the laboratory. The exposed individuals also exhibited polymorphism with respect to the loci of esterase, as compared to an unexposed control plants. Therefore, the present study suggests EST variations of L. minor to be a potential biomarker of heavy metal pollution.

Araceae↗
PubMed2002

Dynamic critical behavior of failure and plastic deformation in the random fiber bundle model.

The random fiber bundle (RFB) model, with the strength of the fibers distributed uniformly within a finite interval, is studied under the assumption of global load sharing among all unbroken fibers of the bundle. At any fixed value of the applied stress sigma (load per fiber initially present in the bundle), the fraction U(t)(sigma) of fibers that remain unbroken at successive time steps t is shown to follow simple recurrence relations. The model is found to have stable fixed point U*, filled (sigma) for applied stress in the range 0 < or = sigma < or = sigma(c), beyond which total failure of the bundle takes place discontinuously [abruptly from U*, filled (sigma(c)) to 0]. The dynamic critical behavior near this sigma(c) has been studied for this model analyzing the recurrence relations. We also investigated the finite size scaling behavior near sigma(c). At the critical point sigma = sigma(c), one finds strict power law decay (with time t) of the fraction of unbroken fibers U(t)(sigma(c)) (as t--> infinity). The avalanche size distribution for this mean-field dynamics of failure at sigma < sigma(c) has been studied. The elastic response of the RFB model has also been studied analytically for a specific probability distribution of fiber strengths, where the bundle shows plastic behavior before complete failure, following an initial linear response.

Journal Article↗
PubMed2001

Identification of the I(pi) = 10(+) Yrast rotational state in 24Mg.

Spins and parities of high spin states above the particle-binding threshold in 24Mg were determined with a basis expansion technique using triple and quadruple angular correlations between alpha particles and gamma rays. The first unambiguous identification of a 10(+) state is reported. Located at 19.2(1) MeV, this state decays predominantly by alpha emission, although a candidate gamma-decay branch with a 5.927 MeV transition connecting this 10(+) level to the rotational 8(+) state at 13.2 MeV was identified as well. The corresponding gamma-alpha branching ratio is 7(3)x10(-4).

Journal Article↗
PubMed2001

Magic nucleus 132Sn and its one-neutron-hole neighbor 131Sn.

Prompt and delayed gamma-ray cascades in doubly magic 132Sn and its neighbor 131Sn have been studied at Gammasphere using a 248Cm fission source. Isotopic assignments of unknown gamma rays were based on coincidences with known transitions in A = 112-116 Pd fission partners. The yrast level spectra of both tin nuclei are interpreted using empirical nucleon-nucleon interactions from the 132Sn and 208Pb regions. Results include identification of the (nuf(7/2)h(-1)(11/2))9(+) aligned state in 132Sn and of extensive (nuf(7/2)h(-2)(11/2)), (nuf(7/2)d(-1)(3/2)h(-1)(11/2)) and (nuh(-1)(11/2)x3(-)) multiplets in 131Sn. The previously reported beta(-) decay of an unusual 131In high-spin isomer to levels in 131Sn is also elucidated.

Journal Article↗
PubMed2001

Effect of a herbal protein CI-1, purified from Cajanus indicus on the ultrastructural study of hepatocytes, in models of liver failure in mice.

Ultrastructural changes in acute liver damage models in swiss albino mice (male, 30 g +/-2) induced by CCl(4) (0.1 ml/100 g); beta-galactosamine (500 mg/kg); paracetamol (300-500 mg/kg) and 40% ethanol (2 ml/100 g) were studied. Electron microscopical studies of hepatocytes of treated (hepatotoxins) mice showed-dilation of ER of both rough and smooth type with swollen mitochondria. Ethanol treated mouse hepatocytes showed giant mitochondria and presence of balloon cells. Nuclear changes showed increase in size and striking anisonucleosis, especially in CCl(4) and paracetamol treated mouse hepatocytes. Condensation of chromatin, nucleoli were fragmented and dispersed in beta-galactosamine induced hepatotoxic mice. These changes are remarkably striking in contrast to control animals. Treatment with CI-1, the herbal protein isolated from Cajanus indicus inhibited the pathogenesis of a majority of lesions produced by the hepatotoxins. Slender mitochondria, array of granular ER, presence of binucleated cells are the salient features of CI-1 treated hepatotoxic mice. Ultrastructurally, the hepatocytes of CI-1 treated mice were near normal. Thus, the herbal protein CI-1, may be a useful approach in the treatment of liver disorders for its potential in clinical medicine.

Acetaminophen↗
PubMed2000

Phase transitions above the Yrast line in 154Dy.

Spectra of the E2 quasicontinuum gamma rays feeding different spin regions of the 154Dy yrast line have been extracted. These are compared with corresponding theoretical spectra obtained by numerical simulations based on temperature-dependent Hartree-Fock theory, with thermal shape fluctuations. In this manner, different regions of the spin-energy plane can be examined. The results support the predictions of a smeared-out phase transition at high spin above the yrast line.

Journal Article↗
PubMed2000

Reaction of

Explore the source record for details and available documents.

Journal Article↗
PubMed2000

Entry distribution, fission barrier, and formation mechanism of 254102No

The entry distribution in angular momentum and excitation energy for the formation of 254No has been measured after the 208Pb(48Ca,2n) reaction at 215 and 219 MeV. This nucleus is populated up to spin 22Planck's over 2pi and excitation energy greater, similar6 MeV above the yrast line, with the half-maximum points of the energy distributions at approximately 5 MeV for spins between 12Planck's over 2pi and 22Planck's over 2pi. This suggests that the fission barrier is greater, similar5 MeV and that the shell-correction energy persists to high spin.

Journal Article↗
PubMed2000

Current recommendations of chemotherapy and pharmacology of antituberculosis drugs.

Due to presence of natural mutant bacilli, existence of the bacilli in several populations and in various sites, combination of two, three or more drugs is necessary to treat tuberculosis and that too for a long time. Inadequate therapy leads to relapse and treatment failure. The cumulative effect of negligence, mistakes and new threats (e.g., HIV infection) has made the treatment difficult today. The National Tuberculosis Control Programme of 1962 has been modified recently by Revised National Tuberculosis Control Programme. The targets are to detect at least 70% of new smear positive cases and to achieve at least 85% cure rate by Directly Observed Therapy Short course (DOTS). Categorisation of patients and treatment recommendations are discussed along with pharmacology of antituberculosis drugs.

AIDS-Related Opportunistic Infections↗
PubMed1999

Effect of a herbal protein, CI-1, isolated from Cajanus indicus on immune response of control and stressed mice.

The effect of a herbal protein, CI-1, purified from the leaves of Cajanus indicus was evaluated as a probable immunomodulator on immune response in control and stressed mice. In mice, sensitized with sheep red blood cells (SRBC), CI-1 enhanced IgG level by 28% over control (P < 0.05). Primary and secondary antibody response to SRBC and bovine serum albumin (BSA) were significantly increased in CI-1 treated group. Furthermore CI-1 facilitated the delayed type of hypersensitivity (DTH) response to SRBC in sensitized mice and also enhanced leucocyte and macrophage migration inhibition response in immunized mice. A fewer mice displayed symptoms of anaphylactic shock after CI-1 administration at a dose of 6.0 mg/kg body wt. in BSA sensitized mice. The immediate effect of CI-1 on anaphylactic shock was not seen when 150 microg of CI-1 was injected in combination with BSA in the shocking injection. These results suggest that CI-1 influences both humoral and cell-mediated immune response.

Adjuvants, Immunologic↗
PubMed1999

Hepatoprotective activity of a herbal protein CI-1, purified from Cajanus indicus against beta-galactosamine HCl toxicity in isolated rat hepatocytes.

A herbal protein, CI-1 purified from a leguminous plant Cajanus indicus, showed dose dependent-(1.5-6.0 mg/kg x 7 days) protective activity on isolated hepatocytes (ex vivo) against beta-galactosamine-HCl induced hepatic damage in rats. It enhanced the percent viability of the hepatocytes following beta--galactosamine treatment. CI-1 was also effective in counteracting the toxic effects of beta-galactosamine, as shown by reversed levels of the altered enzymes, glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transminase (GPT) and alkaline phosphatase (ALP) both in isolated hepatic cells as well as in serum. In comparison silymarin, a known hepatoprotective agent, produced dose related protection at-relatively much higher doses than CI-1.

Alanine Transaminase↗
PubMed1998

Immunosuppressive effect of vestibulo-cerebellar lesion in rats.

Kainate lesion of the vestibulo cerebellum induces sympathetic hyperactivity, but the mechanism of immunosuppression observed as a result is not yet clarified. Here we report that vestibulo cerebellum lesioned (VCL) rats have depressed secretion of haematopoietic cytokines (bioimmunomodulator or BIM, a 12.7 kD peptide and thymosin FrV) in tissue cultures of bone marrow and thymus, respectively, compared with controls (P < 0.01). Peripheral blood leukocyte concentration, neutrophil myeloperoxydase response, T-SRBC rosette and antibody titre to sheep red blood cells (SRBC) are also significantly less, compared with control (P < 0.01). Injection of BIM (concentration 0.01 microg/g body weight) in VCL rats corrected the immunodeficiency. Partial restoration of immune competence is observed after injection of thymosin FrV (0.01 microg/g body weight) or after prolonged vestibular stimulation (18 rpm for 15 min/day for 21 days). The results indicate that the vestibular nodule (VN) through autonomic nerves (AN) can modulate the immune function of rats by regulating the secretion of cytokines from bone marrow and thymus.

Animals↗
PubMed1998

Role of bone marrow and thymus secretory protein in maintaining immune homeostasis and haemopoiesis in control and malnourished mice.

Injection of Salmonella typhi 'H' antigen was observed to produce a differential effect on bone marrow and thymus secretory profile depending upon the nutritional status of the host. The paracrine effect of Thy F1 (thymus fraction 1) was more significant (P < 0.01) than the autocrine effect of BIM (Bone marrow immunomodulator) in malnourished mice. BIM moreover, also had a paracrine effect on thymus irrespective of the nutritional status of the host. An improvement in neutrophil population (P < 0.01) and phagocytic myeloperoxidase activity (P < 0.01) was observed in BIM treated malnourished immuno-suppressed mice, whereas no appreciable change was observed by Thy F1. However, Thy F1 irrespective of the nutritional status of the host improved large lymphocyte population in circulation (P < 0.01). These findings indicate that both bone marrow and thymus play a major role in haemopoietic microenvironment of BDF (basal diet fed) control and malnourished mice.

Animals↗
PubMed1998

Anti-implantation effect of a bone-marrow cytokine-BIM.

Successful implantation of blastocyst is dependent upon a cytokine induced localized immunosuppression at uterus. BIM, a bone marrow secreted bio-immunomodulator (BIM) has been observed to have positive immunomodulatory activity in immunosuppressed cases. As pregnancy is associated with immunosuppression upregulation of the suppressed immune system by injection of BIM (conc. 0.08 microg/g b.wt once in rats b.wt. <150 gm or 0.2 microg/g b.wt thrice in rats weighing > 160 gm) is believed to prevent implantation. The anti-implantation action of BIM is probably mediated via mononuclear cells at site of uterus, the effect is reversible and a single dose did not affect the estrous cycle. Multiple dose of BIM however, produce prolonged diestrous and this is probably an autonomic phenomena.

Adjuvants, Immunologic↗
PubMed1998

Hepatoprotective effect of a protein isolated from Cajanus indicus (Spreng) on carbon tetrachloride induced hepatotoxicity in mice.

Treatment with hepatotoxin namely carbon tetrachloride (CCl4) (0.1 ml/100 g of body weight; twice a week) induced acute hepatic necrosis in Swiss albino mice (male; body weight 30 g +/- 2), with significant alteration in the activities of glutamic oxaloacetic transaminase (GOT); glutamic pyruvic transaminase (GPT); alkaline phosphatase (AP) and serum bilirubin. Administration of a protein fraction isolated from the leaves of C. indicus counteracted the action of CCl4 on transaminase, phosphatase showing hepatoprotection. Daily treatment with a purified protein fraction 'X' from the above plant (0.5 mouse ml i.p; 50-60 micrograms/ml) for a period of 7, 14, 21 days respectively showed decreased activities of serum transaminases alkaline phosphatase and decreased levels of serum bilirubin. These findings were further confirmed by histopathological study of liver.

Animals↗
PubMed1997

Effect of thiocyanate ingestion through milk on thyroid hormone homeostasis in women.

A thyroid-hormonal evaluation of thirty-five women consuming commercially packed milk containing thiocyanate was carried out. The mean serum thiocyanate concentration, which was measured by the FeCl3 colour test, was significantly higher (P < 0.01) than that of control subjects. Serum thyroxine (T4), triiodothyronine (T3) and thyroid-stimulating hormone (TSH) concentrations of exposed women were compared with those of thirty-five control subjects. Thiocyanate ingestion was associated with lower levels of T4 (P < 0.01) and higher levels of TSH (P < 0.01) compared with the control subjects. T3 was found to be higher in the women consuming thiocyanate-containing milk but the difference was not significant. The serum T4 level was found to be negatively correlated (r -0.359, P < 0.05) while the TSH level was positively correlated (r 0.354, P < 0.05) with thiocyanate concentration in the exposed group. From this study, it appears that ingestion of milk with added thiocyanate impairs thyroid function.

Animals↗