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Biomedical subjects

A Varma

Publications and source records attributed to A Varma.

At least 91 records · Page 5Linked to original sources
PubMed1980

Relationship of serum T4 and T3 to TSH in primary hypothyroidism.

The relationship of serum thyroxine (T4) and 3,5,3'-triiodothyronine (T3) to the thyroid-stimulating hormone (TSH) response to protirelin was studied in 34 hypothyroid patients on a stable maintenance dose of oral levo-thyroxine. Release of TSH from the anterior pituitary, as measured by basal TSH and the TSH response to protirelin, correlated better with serum T4 than serum T3. Our study supports the concept that, in treated hypothyroid patients, serum T4 has a greater relative importance in mediating the actions of thyroid hormone on the anterior pituitary than serum T3.

Adult↗
PubMed1977

The relationship between rumen bacterial growth, intake of dry matter, digestible organic matter and volatile fatty acid production in buffalo (Bos bubalis) calves.

1. The production rates of bacteria in the rumen of buffalo (Bos bubalis) calves were estimated using an isotope-dilution technique. A series of fifteen experiments was done with animals given green maize and nine experiments with animals given cowpea (Vigna unguiculata). 2. The turnover time ranged from 205 to 567 min in the group given green maize and from 330 to 648 min in animals offered cowpea. The production rates of bacteria were (mean +/- SE; g/d) 145.77 +/- 7.240 and 237.09 +/- 11.847 in animals given green maize and cowpea respectively. 3. There was a significant correlation between bacterial production rates and dry matter intake, digestible organic matter and total volatile fatty acids formed in the rumen. 4. Regression equations obtained for the two foodstuffs were different suggesting that the bacterial growth rate may vary depending upon the quantity and quality of foodstuff digested and possibly the ratio nitrogen:energy of the foodstuff.

Animal Feed↗
PubMed1973

Quantitative assay of a plasma factor deficient in von Willebrand's disease that is necessary for platelet aggregation. Relationship to factor VIII procoagulant activity and antigen content.

In a previous paper, we showed that the abnormality of ristocetin-induced platelet aggregation in platelet-rich plasma in 10 patients with von Willebrand's disease could be corrected by a factor in normal plasma that was present in the same fractions as factor VIII procoagulant activity (antihemophilic factor, AHF, VIII(AHF)) when prepared by chromatography on Bio-Gel 5 M (Bio-Rad Laboratories, Richmond, Calif.). This observation suggests that patients with this disorder are deficient in a plasma factor, associated with the factor VIII molecule, that is necessary for normal platelet function. In the present paper, we describe, an assay for this factor, the von Willebrand factor (VIII(VWF)), based on the observation that a log-log relationship exists between the amount of ristocetin-induced aggregation of washed, normal platelets and the concentration of normal plasma present in the test system. We assayed the activity of VIII(VWF) as well as antihemophilic factor procoagulant activity (VIII(AHF)) and factor VIII antigen (VIII(AGN)) in 15 patients with von Willebrand's disease and 20 normal subjects. A highly significant correlation (r approximately 0.80) between VIII(VWF) and both VIII(AHF) was found in normal subjects and in patients with von Willebrand's disease. This finding, in addition to the observation that agarose gel chromatography fractions that have VIII(AHF) procoagulant activity also have VIII(VWF) activity, strongly suggests that the von Willebrand factor is associated with the factor VIII molecule. VIII(VWF) in normal plasma was not inhibited by human anti-VIII, and VIII(VWF) levels were normal in hemophilic plasma. Thus, the VIII(VWF) site on the factor VIII molecule appears to be different from that determining VIII(AHF). Finally, the activity of VIII(VWF) appeared to correlate better with the bleeding time than either VIII(AHF) or VIII(AGN). This suggests that VIII(VWF) assayed in this study may be the "anti-bleeding factor" that is deficient in von Willebrand's disease. These findings are consistent with a decreased synthesis of the factor VIII molecule in von Willebrand's disease and suggest the possibility of additional abnormalities of the site on the molecule that determines the activity of VIII(VWF).

Adult↗
PubMedDate not supplied

Improved thin layer chromatographic resolution of PTH amino acids with some new solvent systems.

Three new solvent systems, pyridine: benzene (2.5:20, v/v), methanol:carbon tetrachloride (1:20, v/v) and acetone:dichloromethane (0.3:8, v/v), for the resolution of a mixture of 18 PTH amino acids have been reported. Using these solvent systems, various combinations of PTH amino acids which had previously posed resolution problems have been resolved and identified.

Acetone↗
PubMedDate not supplied

Trichobezoar with small bowel obstruction.

Trichobezoar is a rare clinical entity. Stomach is the common site of occurrence. Intestinal obstruction due to trichobezoar is extremely rare. We report a case of subacute bowel obstruction in a 7-year-old girl which required resection of the involved ileal segment and release of small bowel adhesions.

Bezoars↗
PubMedDate not supplied

Application of population balance model to the loss of hybridoma antibody productivity.

A simple dynamic model has been applied to explain the population dynamics of monoclonal antibody (MAb) producing (producer) and nonproducing hybridoma cells (nonproducer) coexisting in culture. The events of mutation or loss of genes associated with antibody synthesis have been incorporated into the model to account for the conversion of a producer to a nonproducer. The model shows that the cell population is not necessarily dominated by the nonproducer, and a steady balance of producer and nonproducer populations can be achieved. A nonproducer population is undesirable, and cultivation strategies to maximize MAb production are suggested, taking into account the dynamics of a nonproducer population.

Antibodies, Monoclonal↗
PubMedDate not supplied

Transmission of enteric non-A, non-B hepatitis virus in Macaca mulatta monkeys by intraportal route: subsequent passages of HEV virus.

Macaca mulatta monkeys have been used for the transmission of enteric non-A, non-B hepatitis (HEV) virus by intraportal route. Subsequent passages of HEV virus have been completed in these monkeys. In the first passage, 2 monkeys were inoculated by intra-portal route with 27-34 nm virus-like particles (VLP) obtained from known epidemics of HEV hepatitis in India, and biochemical and serological changes in the blood, histological changes in the liver and excretion of 27-34 nm VLP in the stool were studied. Results were compared with those of 4 negative control monkeys inoculated with stool extracts from healthy individuals. The second passage of 27-34 nm VLP was carried out on 2 monkeys using pools of stool suspension positive for 27-34 nm VLP from first passaged animals. Similarly, the third passage of 27-34 nm VLP was completed intraportally in another monkey. All monkeys developed acute hepatitis, as evidenced by transient elevation of aminotransferase, histopathological changes in the liver, development of antibodies aggregating 27-34 nm VLP and excretion of 27-34 nm VLP in stools. No control monkeys developed these features.

Animals↗