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P C Das

Publications and source records attributed to P C Das.

At least 19 recordsLinked to original sources
PubMed1992

Evaluation of elutriated single donor platelets collected and stored in a closed system.

Single donor platelets (SDPC) were collected by the elutriation technique in a closed-system integrated with large storage containers. Seven runs of SDPC were stored in a 1.5 liter polyvinyl-chloride trimellitate (PVC-TOTM) storage container, making the ratio of platelet concentrate volume to container volume 1:4.5. An equal volume of pooled multiple donor platelet concentrates (MDPC) was stored in parallel under the same conditions. All haematological data were comparable for both products, except for the degree of leukocyte contamination (5-fold increase in the pool). Under these conditions, the functional, morphological, and metabolic characteristics of elutriated platelets throughout 7-day storage were superior to those of pooled platelets. Although the platelet count was not significantly different in both types of concentrates, the mean pH of pooled MDPC fell to 6.0 on day 5 of storage. Leukocytes were shown to contribute to this pH fall. The extent of cell damage, however, as evidenced by LDH leakage (42.7 LDH units/10(11) platelets/day by differential centrifugation, compared to 5.3 units by elutriation) could not be explained solely on the basis of the leukocyte effect. This indicated that the processing method itself influences the platelet quality. By increasing the surface/volume ratio of SDPC, the initial pH of 7.1 was well maintained throughout storage, platelet metabolic rate was slowed, and the function and ultrastructure improved significantly.

Blood Donors↗
PubMed1992

Spigelian hernia.

Explore the source record for details and available documents.

Child, Preschool↗
PubMed1991

Effect of EDTA on platelet count and other platelet parameters in blood and blood components collected with CPDA-1.

We have shown in this study that addition of dried K2EDTA (1.5 mg/ml) to blood samples anticoagulated with CPDA-1 increases significantly the platelet count and mean platelet volume (MPV) of whole blood, red cell concentrate (RCC) and platelet concentrate (PC), but not of platelet-rich plasma (PRP) or of platelet-poor plasma (PPP). Transmission and scanning electron microscopy illustrated that platelet aggregates which are present in some components are dispersed on mixing of the sample with EDTA and that this is accompanied by a change in platelet morphology. Determination of the platelet distribution width (PDW) indicated that the platelet populations in whole blood and RCC seem to be more uniform in size than the populations in PRP, PPP and PC. The determination of MPV and PDW changes after addition of EDTA may provide a new approach to quality control of PC.

Adenine↗
PubMed1990

A simplified method for purification, concentration and freezing of bone marrow cells for autologous transplantation.

Autologous bone marrow (BM) transplantation is being increasingly applied in hematological and oncological patients. However, because of the need to purify and preserve BM requiring high technology, such treatments are virtually concentrated in the "developed" countries. This paper examines methods of BM purification and freezing that could make the technique potentially applicable in developing countries. Hemapheresis is routinely applied for BM purification in our Dutch Centre, where the buffy coats obtained from routine blood donations were utilised in experimental settings. Using DMSO as cryoprotectant, semi-purified white cells were frozen in liquid N2 (LN2), by mechanical freezer or snap-frozen at -55 degrees C. Different types of containers were compared including plastic tubes and ordinary blood bags. After thawing the results show that snap-freezing had a deleterious effect but the cell yields and viability were similar in LN2 or the mechanical freezer where the tubes and the bag were equally effective as containers (86% cell recovery with 90% viability). In the purification/concentration stage, reduction of the volume of the material by extra centrifugation, thus requiring less DMSO, produced better results--96% cell yield and 90% viability after thawing. This simplified method was applied in a general hospital in Sao Paulo where four oncology patients underwent BM collection. BM was purified and concentrated within a blood bank facility. Hydroxyethyl starch sedimentation and centrifugation of the material in plastic blood bags gave 80% BM cell harvest. After thawing from the mechanical freezer 1 x 10(8) BM cells/kg were available for reinfusion to patients. There was no immediate untoward reaction. Three of the patients showed signs of bone marrow regeneration by three weeks, but one patient died 16 days after transplantation, of septicemia. We conclude that certain high-technology procedures for ABMT can be adapted for existing facilities in developing countries.

Bone Marrow Transplantation↗
PubMed1988

Double cryoprecipitated factor VIII concentrate from heparinised plasma and its heat treatment.

In an attempt to implement the small pool concept in Factor VIII purification, cryoprecipitate derived from heparinised plasma was reprecipitated in the cold providing a factor VIII concentrate for freeze drying and heat treatment. There was considerable purification; only 1% of the original plasma proteins was left in the final product. Factor VIII:C concentration was about 19 IU/ml. Factor VIII related antigen (RAg) appeared heterogeneous, with a broad base and asymmetry on crossed immunoelectrophoresis. Fibrinogen content was 15 g/l. In contrast to high-purity commercial concentrates, fibronectin was considerably concentrated. Immunoglobulin contents were similar to a high-purity commercial product. The amount of other plasma proteins was very small, varying from less than 0.2% for C3 complement to 2.3% ceruloplasmin. In some respects the preparation may be considered as an intermediate-purity Factor VIII concentrate. Following addition of 2% sucrose before freeze drying, Factor VIII, total protein and fibrinogen remain virtually stable (less than 15% loss) during heating of the material to 60, 64 or 68 degrees C for 24 to 72 h without changes of protein spectrum following heating. The heated product when stored at 4 degrees C remains stable for at least 3 months. In two severe haemophiliacs receiving this heat treated product, in vivo Factor VIII recovery was 100% with a mean half life of 10.2 h.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Tissue ascorbate as a metabolic marker in cadmium toxicity.

Daily subcutaneous injection of cadmium chloride for two weeks to normal and protein restricted rats show significant increase in the wet weight of liver, kidney, adrenal and decrease in pituitary, testis and thyroid, while no significant changes are observed in the brain. The concentration of ascorbic acid (AA) decreased significantly in plasma, liver, kidney, spleen, adrenal, pituitary and brain but increased in testis and thyroid whereas no significant alteration was observed in the pancreas after cadmium treatment in both the dietary regimen. It is apparent that cadmium causes the alteration of AA in different tissues/organs of the body in normal protein dietary state which is further potentiated in protein restricted condition. During stress, the metabolism of different tissues responds differentially as far as their AA concentration is concerned. Therefore the alteration of AA level in the different tissues/organs might have some correlation with the extent of cadmium toxicity.

Adrenal Glands↗
PubMed1988

Utility of frozen platelets for a platelet antibody assay using flow cytometric analysis.

The immunoreactivity of a PLA1 antibody-containing serum to frozen/thawed platelets prepared by four different procedures was measured to assess the practicality of preparing a platelet reagent that could be easily stored and readily used in an immunofluorescent platelet antibody detection system. These frozen aliquots were analyzed at intervals up to 23 weeks after initial freezing and storage. For analysis, the frozen platelets were thawed, washed, resuspended to 2.5 x 10(5) platelets/mL and incubated with a dilution of fresh autologous serum that lacked platelet antibody or with a similar dilution of frozen human serum containing IgG anti-PLA1 antibody. At each interval, a freshly drawn platelet sample from the same donor was incubated in the same manner and used for comparison. All platelet mixtures were then washed and incubated with fluorescein conjugated goat F (ab')2 antihuman IgG. After repeat washing, each mixture was then analyzed with a flow cytometer for the extent of fluorescent antibody bound to each platelet mixture. Anti-PLA1 antibody reactivity with either the fresh or the frozen/thawed platelets remained stable over the period of analysis, with no significant difference in immunofluorescence with either fresh or frozen platelets as target cells. Platelet recovery following the thawing step ranged from 12% to 36% and was independent of the storage time. These studies suggest that frozen platelets can be readily used as reagents for platelet antibody assays.

Antibodies↗
PubMed1988

Effect of combined contraceptive steroid on rat brain ascorbate-acetylcholine with reference to protein restriction.

To evaluate the effects of combined contraceptive steroids on brain ascorbic acid and acetylcholine during protein restriction with respect to normal dietary condition the rats were subjected to normal (18% casein) and protein restricted (5% casein) diet for 28 days. Subsequently they were treated with combined contraceptive steroids for 28 days. Smear study were performed throughout the periods of dietary regimen and the drug treatment. Ascorbic acid and acetylcholine concentration of six discrete regions of brain were estimated from all groups of rats. At normal dietary state the combined contraceptive steroids significantly increase the ascorbic acid and decrease the acetylcholine concentration in the brain areas. At this state diestrus phase was indicated by smear study. After steroid treatment during protein restriction significant decrease of ascorbic acid and significant increase of acetylcholine concentration occurred in the brain areas. Proestrus and estrus phases were continued as indicated by smear study. It may therefore be presumed that contraceptive steroids affect the brain regional ascorbic acid and acetylcholine in an opposite manner during normal and protein restricted dietary condition.

Acetylcholine↗