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Biomedical subjects

R Prasad

Publications and source records attributed to R Prasad.

At least 397 records · Page 22Linked to original sources
PubMed1975

Enzymatic differentiation in human amniotic cells.

Enzymatic study in noncultured amniotic fluid cells from 87 women at different stages of pregnancy was performed by electrophoresis. Of these patients, 33 had normal pregnancies and the remaining 54 had various complications of pregnancy. The electrophoretic patterns of lactate dehydrogenase, alpha-esterase, and acid phophatase were altered in samples obtained either at different gestation periods or from normal and complicated pregnancies. Malate dehydrogenase and protein bands did not show any alteration. Glucose-6-phosphate dehydrogenase and alkaline phophatase were not detectable. 6-Phosphogluconate dehydrogenase was detectable in samples of complicated pregnancies. The significance of the altered patterns of enzymes is discussed.

Acid Phosphatase↗
PubMed1975

Effect of phospholipase A on active transport of amino acids with membrane vesicles of Mycobacterium phlei.

Active transport of proline remained unaffected in phospholipase A-treated electron transport particles from Mycobacterium phlei. However, the steady state level of proline was reduced 50 to 60% in phospholipase A-treated depleted electron transport particles that were devoid of membrane-bound coupling factor-latent ATPase activity. The decrease in the uptake of proline in the phospholipase A-treated depleted electron transport particles was not due to a change in the apparent K-m for proline, but it was related to the amount of phospholipid cleaved from the membranes. Restoration in the level of proline transport in phospholipase A-treated depleted electron transport particles was achieved by reconstituting these vesicles with diphosphatidylglycerol and phosphatidylethanolamine liposomes. Diphosphatidylglycerol was found to be most effective in the restoration of proline uptake. In contrast to the effect of phospholipase A treatment on proline transport, similar treatement of the electron transport particles or depleted electron transport particles failed to inhibit the active transport of either glutamine or glutamic acid. Studies with phospholipase A-treated membrane vesicles confirmed earlier findings that a proton gradient is not required for active transport of amino acids.

Adenosine Triphosphatases↗
PubMed1975

Effect of phospholipase A on the structure and functions of membrane vesicles from Mycobacterium phlei.

The phospholipid composition of the electron transport particles and coupling factor-depleted electron transport particles of Mycobacterium phlei are the same, but they differ in contents. The accessibility of partially purified phospholipase A to these membrane phospholipids was found to be different. Treatment of membranes of Mycobacterium phlei with phospholipase A impairs the rate of oxidation as well as phosphorylation. The inhibition of phosphorylation can be reversed by washing the membranes with defatted bovine serum albumin. The reconstitution of membrane-bound coupling factor-latent ATPase activity to phospholipase A-treated depleted electron transport particles and their capacity to couple phosphorylation to oxidation of substrates remained unaffected after phospholipase A treatment. However, the pH gradient as measured by bromthymol blue was not restored after reconstitution of phospholipase A-treated depleted electron transport particles with membrane-bound coupling factor-latent ATPase. These findings show that the phosphorylation coupled to the oxidation of substrates can take place without a pronounced pH gradient in these membrane vesicles. The dye 1-anilino-8-naphthalene sulfonic acid (ANS) exhibited low levels of energized and nonenergized fluorescence in phospholipase A-treated membranes. This decrease in the level of ANS fluorescence in phospholipase A-treated membranes was found to be directly related to the amount of phospholipids cleaved. The decrease in the energy-dependent ANS response in phospholipase A-treated electron transport particles, as compared with untreated electron transport particles, was shown to be a result of a change in the apparent K-d of the dye-membrane complex, and of a decrease in the number of irreversible or slowly reversible binding sites, with no change in the relative quantum efficiency of the dye. The decrease in ANS fluorescence in phospholipase A-treated particles appears to be due to a decrease in the hydrophobicity of the membranes.

Anilino Naphthalenesulfonates↗
PubMed1975

Radioimmunoassays for Ig classes G, A, M, D, and E in spinal fluids: normal values of different age groups.

Radioimmunoassay procedures of sufficient sensitivity (IgG, 0.5 mug per 100 mul; IgA, 25.0 ng. per 100 mul; IgM, 10.0 ng. per 100 mul; IgD, 0.5 U. per 100 mul; and IgE, 1.0 U. per 100 mul) were developed detect and quantitate all 5 immunoglobulin classes in the cerebrospinal fluid on small aliquots (1 ml.) of unconcentrated cerebrospinal fluid. All 5 immunoglobulin classes were routinely detected in normal individuals for the first time, the levels varying with different age groups for IgG and A but not for the remaining immunoglobulin classes. Race and sex had no effect. Standardization of techniques and establishment of normal values for different age groups sets the stage for determination of immunoglobulin changes related to central nervous system disease.

Adolescent↗
PubMed1973

Esterase, malate, and lactate dehydrogenases activity in murine neuroblastoma.

Mouse neuroblastoma tumors have only the fifth isozyme band (A(4)) of lactate dehydrogenase, whereas this band is missing in the brain which contained four other bands of lactate dehydrogenase. The alpha-esterase isozyme patterns of tumors, kidney, and brain are similar except that there is an additional slowest-moving form of esterase in all tumor tissues. The malate dehydrogenase pattern is not altered in any of the tissues.

Animals↗