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Biomedical subjects

P Bhattacharya

Publications and source records attributed to P Bhattacharya.

At least 37 records · Page 2Linked to original sources
PubMed2000

Localization of phosphate dependent glutaminase in ascites fluid of ovarian cancer patient.

Phosphate dependent glutaminase was purified from ascites fluid of ovarian cancer patients. The purified enzyme showed a final specific activity of 110 unit / mg protein with 72 fold purification and 21% yield. Purified enzyme gives one dark band of Mr approximately 65.5 KD and two light bands of Mr approximately 47.5 KD and approximately 45 KD respectively on 10% SDS-PAGE. One major immunoreactive band was found in trans-immunoblot analysis using antibodies against rat kidney and ascites fluid glutaminase raised in rabbit and mice respectively. Phosphate dependent glutaminase enzyme purified from mitochondria of malignant and non malignant ovarian tissue also showed bands of same molecular weight on 10% SDS-PAGE and gave same immunoreactive bands in trans-immunoblot like the purified glutaminase from ascites fluid. This result was confirmed by using the specific activity stain for glutaminase, which indicates that same enzyme activity is probably due to leakage of the same enzyme from malignant tissue into the ascites fluid. The purified enzyme from human peritoneal fluid showed a high specificity toward glutamine, therefore is a true glutaminase. Moreover, ascites fluid taken from patients of different age group with different stages of ovarian carcinoma revealed the presence of same glutaminase on 10% SDS-PAGE, and exhibited immunoreaction on ELISA, trans-immunoblot and dot immunoblot analysis.

Adult↗
PubMed2000

A general survey of glutamine level in different tissues of murine solid tumor bearing mice before and after therapy with purified glutaminase.

Distribution of glutamine level in different tissues of tumor bearing mice such as brain, liver, kidney, spleen, large and small intestine and the tumor itself were studied in three solid tumor models, viz, Ehrlich ascites carcinoma, Sarcoma-180 and methylcholanthrene induced carcinoma. Tumor bearing mice were subjected to therapy for 7 days with the glutaminase purified from malignant S-180 cell. The results exhibit a significant decrease in tumor burden after enzyme therapy. Host tissue glutamine levels were significantly elevated in tumor bearing untreated mice in comparison to the normal ones, while significant lower values were obtained after enzyme therapy. It therefore appears that elevated levels of glutamine in host tissue are associated with the tumor burden.

Animals↗
PubMed2000

Neovascularisation offers a new perspective to glutamine related therapy.

Angiogenesis or the generation of new blood vessel, is an important factor in the growth of a solid tumor. Hence, it becomes a necessary parameter of any kind of therapeutic study. Glutamine is an essential nutrient of tumor tissue and glutamine related therapy involves clearance of circulatory glutamine by glutaminase. Therefore, using different murine solid tumor models, the present study was undertaken to find out whether the S-180 cell glutaminase has any effect on angiogenesis of solid tumor, or not. Result indicates that the purified S-180 cell glutaminase reduces tumor volume and restrict the generation of neo blood vessels. Therefore, it can be concluded that this enzyme may be an effective device against the cancer metastasis.

Angiogenesis Inhibitors↗
PubMed1999

Angiogenesis a putative new approach in glutamine related therapy.

Angiogenesis or the generation of new blood vessels, is an important factor regarding the growth of a tumor. Hence, it becomes a necessary parameter of any kind in therapeutic studies. Glutamine is an essential nutrient of tumor tissue and glutamine related therapy involves clearance of circulatory glutamine by glutaminase. So, whether this enzyme has any effect on angiogenesis of a tumor or not becomes an obvious question. To address this question, this study has been carried out with different murine tumor models. The results indicate that purified glutaminase reduces tumor volume as well as restricts the generation of new blood vessels. Glutaminase is effective in the case of solid as well as ascites tumor models. In the case of induced cancer, the host exhibits delayed onset of neoplasia following enzyme treatment and tumor host interactions determine the intensity of the neovascularisation process. Therefore, it can be concluded that this enzyme might be an effective agent against cancer metastasis.

Animals↗
PubMed1999

Risk assessment of cardiovascular diseases among bank employees--a biochemical approach.

In different epidemiological studies, an association between sedentary life style and incidence of cardiovascular diseases has been demonstrated. This study was carried out among 50 sedentary bank employees working at different nationalized banks within Calcutta City, India and 50 individuals with non-sedentary jobs matched for age group and sex for the control group. Body mass index (BMI), blood pressure (BP), plasma level of glucose, total cholesterol, low density lipoprotein (LDL), very low density lipoprotein (VLDL) and triglycerides (Tgs) were found to be significantly higher whereas high density lipoprotein (HDL) and reduced glutathione were found to be significantly lower among the bank employees as compared with the control subjects. Further, significant alteration in the activity of different enzymes (e.g., glutathione reductase, glutathione S-transferase, glucose 6 phosphate dehydrogenase, catalase and superoxide dismutase) involved in glutathione-mediated antioxidant scavenging systems and increases in lipid peroxidation were also observed in the bank employees. From the study, it appears that the relative risk for cardiovascular disease is increased among bank employees due to the sedentary nature of their jobs.

Adult↗
PubMed1999

Comparative study of beta-adrenoceptor blocking efficacy of two formulations of esmolol in vivo and in vitro.

The objective of the present study was to compare the cardiovascular beta-blocking activity of two different formulations of esmolol. Spontaneously beating guinea-pig isolated atria and the heart rate and blood pressure of anaesthetized cat were employed in the study to compare the beta-blocking efficacy of the two formulations of esmolol using isoprenaline as an agonist. In guinea-pig isolated atria the standard esmolol formulation (Brevibloc) reduced basal atrial rate more significantly than the indigenously formulated esmolol (test formulation). Both the formulations produced similar parallel rightward shift of cumulative concentration response curves of isoprenaline with closely comparable pA2 values. In anaesthetized cats, only indigenous esmolol formulation significantly decreased basal heart rate. Both the formulations did not modify the basal blood pressure and isoprenaline-induced fall in blood pressure, despite significantly blocking isoprenaline-induced tachycardia. It is suggested that both the formulations produced similar degree of beta-1 adrenoceptor blocking activity.

Adrenergic beta-Antagonists↗
PubMed1999

Isolation and purification of phosphate dependent glutaminase from sarcoma-180 tumor and its antineoplastic effects on murine model system.

High rate of glutamine use is a characteristic of tumor cell both in vivo and in vitro and experimental cancer therapies have developed by depriving tumor cells of glutamine. In several investigations, bacterial glutaminase was found to be a potent therapeutic agent against varieties of tumor, but it showed suppressive effects on haematopoietic systems and inhibitory effects on normal lymphocytic blastogenesis. No antineoplastic study has nevertheless been undertaken with glutaminase enzyme purified from mammalian source. In the present study we report the purification of glutaminase enzyme from mitochondria of highly malignant S-180 cell using ion exchange chromatography and affinity column chromatography of glutamine. Purified enzyme is a kidney type phosphate dependent glutaminase with Mr 64 KD. Effect of enzyme therapy has been investigated in transplantable as well as induced tumor model in both ascites and solid form. It has been observed that the enzyme at the total dose of 10 unit/mouse successfully inhibited the tumor burden both in ascitic and solid tumor and subsequently increases the host's life span. There was no significant toxic effect on the peripheral blood cells.

Animals↗
PubMed1999

Evidence for integration of IS1 and IS10 in recombinant plasmid containing rearrangement hot-spot(rhs) common-shared block(CSB) in Escherichia coli K-12.

The integration of IS1 and IS10 was reported in the recombinant plasmid containing the 3070 bp rearrangement hotspot(rhs) common-shared block(CSB) in Escherichia coli K-12. The integration of IS1 was found to be in rhs(CSB) portion, whereas the integration of IS10 was found to be in both rhs(CSB) and vector portions. The bacterial cells containing the recombinant plasmid grew very slowly. But the integration of IS1 or IS10 in rhs(CSB) portion made the host grow rapidly and overgrew the slow-growing population inheriting the recombinant plasmids without IS-sequences. The sites of integration of IS1 and IS10 were different as was judged from restriction endonuclease mapping. These are rare examples of interchromosomal mobilisation of IS1 and IS10 from host chromosome into plasmid.

DNA Transposable Elements↗
PubMed1999

TSH assay using dried blood samples: a screening method for congenital hypothyroidism.

Capillary blood samples from three hundred healthy, full-term newborn within 48 and 120 hours of delivery, were collected on filter paper for analysis of thyroid-stimulating hormone (TSH). Blood was collected by pricking the heel of the newborn and spotted and dried on filter paper cards. The samples were analysed by immunoradiometric assay (IRMA) to determine the TSH level. Some fifteen percent of a total 1928 deliveries at two hospitals during a period of one year were included in the study. Male:female ratio was 1.1:1. There was no maternal history of thyroid disease. None of the babies had any clinical feature of hypothyroidism. On analysis, TSH level ranged from 0.6-19.3 microU/ml with a mean (SD) of 7.19 (4.21) microU/ml. TSH assay from dried filter paper blood spot is technically possible and is a cost-effective and reliable method for a screening programme. This is the first time in Bangladesh that this method has been successfully carried out.

Bangladesh↗
PubMed1997

Polypeptide pattern of mRNA isolated from polysomal and non-polysomal mRNA-protein(mRNP) fractions in rat myoblast.

Polypeptides synthesized from polysome-bound and unbound fractions of polyA mRNA were studied by in-vivo cells labelling and cDNA-mRNA hybrid-arrest translation. The polypeptides synthesized from unbound(free) fraction appeared to be significantly reduced in the absence of cycloheximide in L6 myoblast. The cDNA excess-mRNA hybrid-arrest translation exhibited rare polypeptide sequences in the unbound fractions.

Animals↗
PubMed1996

A new edge detector for gray volumetric data.

We propose a 3-D edge detector for gray voxel-based data, generalizing the well-known Sobel operator for 2-D images. Three differentiation operators are defined corresponding to the three principal directions (coordinate axes). Each operator computes the sum of the intensity differences between certain pairs of neighbors of a voxel corresponding to a principal direction. The proposed edge detector corresponds to the square root of the average of the squares of the three differentiation operators. Implementation of the proposed operator is given for biological images such as CAT and MRI scan data and an electron density map of a macromolecule.

Algorithms↗
PubMed1996

[Development and characterization of a high-purity human factor VIII concentrate submitted to 2 specific virus inactivation treatments (FANDHI)].

AIM: To develop a therapeutic human high purity FVIII concentrate, treated with two documented and complementary specific inactivation methods, for the treatment of haemophilia A. MATERIAL AND METHODS: Cryoprecipitate was obtained from human plasma, normal for ALT levels and negative for HBsAg and antibodies to HIV and to HCV. The cryoprecipitate was resuspended and purified with PEG. The PEG precipitate was resuspended and treated with TNBP/Polysorbate 80. The mixture was processed by heparin affinity chromatography. The eluate was concentrated and precipitated with glycine and salts. After resuspension, stabilizers were added and the solution was sterile filtered, dispensed in vials and lyophilized. These final vials were treated at 80 degrees C for 72 hours: FVIII:C, vWF:RCo, vWF:Ag, vWF multimeric structure and the concentration of other plasmatic proteins were analyzed. RESULTS: FVIII: C specific activity was between 1000 and 3000 U/mg (after elimination of vWF, present as a stabilizer and before the addition of human pasteurized albumin). vWF:RCo activity (0.7 U vWF:RCo/U FVIII:C) and the multimeric structure of vWF showed a good degree of conservation. Other plasmatic proteins analyzed were undetectable or at trace amounts. No prekalllikrein, kallikrein or activated coagulation factors activity could be detected. CONCLUSION: The FVIII concentrate described shows a high degree of purity and stability, which makes it very suitable for haemophilia A treatment.

Blood↗