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Biomedical subjects

D K Bhattacharya

Publications and source records attributed to D K Bhattacharya.

At least 37 records · Page 2Linked to original sources
PubMed1994

Human immunodeficiency virus infection related to blood transfusion service.

The prevalence of transmissible viruses, human immunodeficiency (HIV) and hepatitis B (HBV) in blood donors, recipients and blood bank staff in a Calcutta (eastern India) based blood bank and transfusion centre has been studied from 1987-93. HIV seropositivity of blood donors was of recent emergence and was low. Recipients of blood and blood components frequently i.e., haemophilics showed a progressive increase in HIV seropositivity since 1988 whereas in thalassaemics the emergence of HIV seropositivity was noted only in 1992. Blood bank staff were seronegative. HBV which has a similar portal of entry as HIV, had a higher prevalence in blood donors, recipients of blood/components and blood bank staff.

Blood Banks↗
PubMed1993

Immunosurveillance of transfusion dependent thalassaemia and hepatitis B vaccination.

The study evaluates the probable alteration of the immune system in multitransfused thalassaemics and the modification of their immune response following administration of hepatitis B virus (HBV) vaccine. B-thalassaemics (n = 50) and EB-thalassaemics (n = 30) who received multiple blood transfusion for the chronic anaemic status had significant iron overload. They had high prevalence for hepatitis B carrier state and almost all were exposed to hepatitis B virus during the course of transfusion as shown by the positivity of hepatitis B virus markers. Thalassaemics in presence of iron overload have altered immune status in terms of depressed T-lymphocytes and raised immunoglobulins G and M. However, they showed 100 per cent seroconversion with production of antibody to hepatitis B surface antigen following Hepatitis B vaccination.

Adolescent↗
PubMed1993

Hepatitis B vaccination and the rate of seroconversion in high risk contacts.

Twenty-seven employees of a blood transfusion centre, Calcutta were vaccinated with hepatitis B vaccine (recombinant DNA technology), 20 micrograms/1 ml intramuscularly on 0, 8, 32 weeks interval. The seroconversion rate at 8, 32, 40 weeks were 29.6%, 55.5% and 100% respectively. The recombinant hepatitis B vaccine is acceptable and safe. The seroconversion rate is comparable to plasma derived hepatitis B vaccine.

Blood Banks↗
PubMed1992

Sero-surveillance of transmissible hepatitis B & C viruses in asymptomatic HIV infection in haemophilics.

In a group of 37 haemophilics, 9 (24.3%) were seropositive for human immunodeficiency virus (HIV), while 9 (24.3%) and 10 (27%) were positive for hepatitis B virus (HBV) and hepatitis C virus (HCV) respectively. Haemophilics who were HIV seropositive had higher prevalence of HBV and HCV. Seropositivity for HIV was more in patients with severe haemophilia A who required frequent factor VIII replacement. The need for long term surveillance of voluntary blood donors for transfusion associated viruses like HIV, HBV and HCV, is emphasized.

Adolescent↗
PubMed1991

Prevalence of hepatitis C in transfusion dependent thalassaemics & haemophilics.

Seventy thalassaemics (B = 37, EB = 33) and 20 haemophilics (A = 18, B = 1, C = 1) were tested for antibodies to hepatitis C virus (anti-HCV) and markers for hepatitis B virus (HBV). The seropositivity for anti-HCV in thalassaemics and haemophilics was 14.3 and 25 per cent respectively. The subjects who were sero-positive to anti-HCV had had additional exposure to HBV. Anti-HCV positivity was not related to the age of the subject nor the number of units of blood and blood components transfused. Screening of blood donors for anti-HCV, apart from HBV, may minimise the hazards of post transfusion hepatitis in high risk recipients like transfusion dependent thalassaemics and haemophilics.

Hemophilia A↗
PubMed1991

Prevalence of hepatitis B virus (HBV) markers and human immunodeficiency virus (HIV) in employees of a blood transfusion centre.

Blood bank staff, 8 out of 25 (32%) have been exposed to hepatitis B virus (HBV) and the prevalence of HBV markers in blood bank employees handling high risk subjects show hepatitis B surface antigen (n = 1), hepatitis B surface antibody (n = 7), hepatitis B core antibody (n = 6) and combined hepatitis B surface antibody and hepatitis B core antibody (n = 6) seropositivity but all are negative to human immunodeficiency virus (HIV). Serum alanine aminotransferase was raised in the employees than normal subjects and it is suggestive of sub-clinical hepatitis. The employees of blood bank should be trained for proper handling of test materials and must be periodically monitored for HBV and HIV. Immunisation for HBV is mandatory only for the employees of transfusion centre which handles high risk subjects.

Biomarkers↗
PubMed1990

Blood donation and risk of post-transfusion hepatitis.

A survey was conducted among 300 blood donors of urban and rural population (the Sunderbans) and paid donors to evaluate the nutritional status, serum proteins, immunoglobulin and alanine aminotransferase (ALT) on the persistence of carrier state for post-transfusion hepatitis (PTH). Paid donors showed lowering of serum albumin and elevation of immunoglobulin and ALT. Nutritional and immunoglobulin profiles of rural donors of the Sunderbans, differed from those of voluntary donors of urban area. In the presence of subclinical hepatitis, ALT measurement alone is not a reliable guide for identification of individual carriers.

Adult↗
PubMed1990

Differential effect of retinoic acid on ADP and collagen induced platelet aggregation.

Retinoic acid (RA) was found to inhibit ADP induced but not collagen induced aggregation of human platelets and the differential action is related to intraplatelet Ca2+ reflux. RA was active at concentrations as low as 10(-7) M and required 20 min prior incubation with platelet suspension in order to inhibit aggregation by ADP. All the steps in ADP induced but not collagen induced platelet activation, viz. hydrolysis of phosphatidyl inositol, phosphorylation of 20, 47 and 250 kDa proteins as well as increased association of actin with Triton X-100 insoluble cytoskeletal matrix were inhibited by RA. RA when used as an agent for differentiation induction of cell progenitor is likely to affect the platelet aggregation and thereby the haemostatic process.

Adenosine Diphosphate↗
PubMed1990

HBV & HIV seropositivity in multi-transfused haemophilics & thalassaemics in eastern India.

Seropositivity to HBV (HBsAg) in multi-transfused patients of haemophilia A, haemophilia B, B thalassaemia and EB thalassaemia from Eastern India, was found to be 9, 0, 22.1 and 13 per cent respectively. HIV seropositivity was detected in patients of haemophilia A (4.4%) and B thalassaemia (0.8%) who received plasma components and packed cells periodically. Seropositivity to both HBsAg and HIV was found in one patient of haemophilia A. Serum alanine amino transferase (ALT), raised in multi-transfused thalassaemics suggests concurrent hepatitis which might have enhanced the transmission of viruses due to disturbed immune status. The universal voluntary blood donation programme, screening of blood for HBV and HIV by sensitive tests, early immunisation and periodic monitoring of HBV and HIV status are prerequisites for the management of transfusion dependent thalassaemia and haemophilia.

Blood Transfusion↗
PubMed1990

Effect of retinoic acid on adenosine diphosphate and collagen-induced alterations in enzymes of GSH-linked antioxidant defence system of human blood platelets in vitro.

Collagen stimulation of blood platelets resulted in significant increases in malondialdehyde (MDA) formation and activity of glucose-6-phosphate dehydrogenase (G6PDH) and a decrease in catalase and glutathione peroxidase (GPx). Retinoic acid (RA) pretreatment did not show any appreciable changes except for a decrease in G6PDH activity as compared with collagen alone. RA pretreatment of human blood platelets resulted in an increase in the activities of catalase and GPx, two important radical scavenging enzymes, with significant decrease in MDA formation when compared with ADP alone. It is suggested that RA has a significant effect on the antioxidant defence system in ADP stimulated platelets but not in the collagen stimulated platelets.

Adenosine Diphosphate↗
PubMed1989

A simple method for preparation of good quality cryoprecipitate.

Production of good quality cryoprecipitate from plasma was achieved, as assessed by quantitating Factor VIII coagulant activity (F VIII C) and Factor related antigen (F VIII R: Ag). The method used resulted in good recovery of FVIII in the cryoprecipitate containing F VIII C: Fibrinogen 0.82 +/- 0.015 IU/mg. The method therefore appears suitable for indigenous preparation of F VIII in standard blood banks as a replacement therapy, which is not expensive.

Centrifugation↗
PubMed1989

Detection of haemophilia A traits in carriers.

Obligate carriers of haemophilia A and normal women matched for age were studied in order to find a suitable parameter for detection of carriers of haemophilia A. The ratio of factor VIII coagulant activities (F VIIIC) to factor VIII related antigen (F VIII R : Ag) was 0.55 in obligate carriers and 1.0 in non-carrier females.

Adult↗
PubMed1989

Uptake of cadmium by isolated human red blood cells.

Uptake of Cd by human RBC in vitro was studied. The uptake was found to be biphasic with a rapid initial phase followed by a slower second phase which was still increasing at the time of the last experiment (60 min). Both the phases were found to be independent of metabolically derived energy and unaffected by zinc in the incubation medium.

Adult↗
PubMed1989

Effects of cadmium treatment in vitro on the uptake and release of [3H]serotonin by human blood platelets.

Effects of cadmium treatment on human platelets were studied with respect to uptake and release of 5-[3H]hydroxytryptamine (5-HT). The uptake of 5-[3H]HT in the presence of varying concentrations of CdCl2 (0.001-10 mM) was inhibited significantly with respect to control platelets and the inhibition was maximum at 1 mM CdCl2 concentration. From studies on the kinetics of 5-[3H]HT uptake a higher Km and significantly lower Vmax for CdCl2-treated platelets were observed. CdCl2 stimulated spontaneous release but inhibited thrombin-induced release of 5-[3H]HT. Spontaneous release of 5-[3H]HT induced by CdCl2 was not significantly altered in the presence of externally available CaCl2 (1 mM).

Blood Platelets↗
PubMed1988

Effects of cadmium treatment in vitro on the antioxidant protection mechanism and activation of human blood platelets.

Interactions of human platelets with cadmium in vitro were studied with respect to the platelet activation process as indicated by malondialdehyde (MDA) formation and also to the components of the cellular antioxidant defence system such as catalase, glutathione peroxidase (GPx), glutathione reductase (GR), glutathione-S-transferase (GST), glucose-6-phosphate dehydrogenase (G6PDH), and reduced glutathione (GSH). Cadmium treatment stimulated platelet MDA formation after a lag phase of at least 15 min and this effect was completely blocked by either 1 mM aspirin or 1 mM CaCl2. Cadmium pretreated platelets also displayed a much higher (5 fold) MDA formation when stimulated by thrombin. Platelet catalase activity was decreased by almost 50% after incubation with cadmium. There was also a moderate decline in platelet GSH and GR activity along with a stimulation of GST and G6PDH activity. These results suggest: (1) the cadmium effect on platelets as observed by enhanced formation of MDA via the cyclooxygenase pathway involves intraplatelet accumulation of cadmium which is inhibited by calcium, (2) a modest decline in GSH, presumably due to the inadequacy of H2O2 detoxification mechanism, does not adversely affect platelet function because of the adaptive response of G6PDH, and (3) intracellular accumulation of cadmium may result in platelet hyperactivity through higher intraplatelet free calcium levels resulting directly through cadmium action or indirectly through higher H2O2 levels due to catalase inhibition.

Adult↗