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M M Baran

Publications and source records attributed to M M Baran.

14 recordsLinked to original sources
PubMed1985

A simultaneous assay for T-cells and B-cells using Immunobeads.

A comparison was made between a new, commercially available light microscope assay for T- and B-lymphocyte enumeration and existing procedures. The Quantigen assay employs two color-coded Immunobeads; one Immunobead binds to and labels T-cells, while the second labels B-cells. Phagocytic cells contaminating lymphocyte preparations ingest both types of beads. A high degree of correlation was found between this simultaneous assay for T- and B-cells and the E-rosette method for T-cells and FITC-labeling of B-cell surface immunoglobulin. The results of a comparison of the Quantigen assay to flow cytometric analyses are also given. Data on chronic lymphocytic leukemia samples are presented, demonstrating that these cells are double-markers with the Quantigen assay because of the use of monoclonal antibody T101, which recognizes T-cells and B-CLL cells.

Antibodies, Monoclonal↗
PubMed1982

Cell sorting using a universally applicable affinity chromatography matrix: solid-phase anti-fluorescein isothiocyanate antibody.

Procedures are described for fractionating cells utilizing a universally applicable cellular affinity chromatography matrix. The affinity matrix consists of immunoabsorption purified goat anti-fluorescein isothiocyanate antibody coupled to large derivatized polyacrylamide beads. This matrix may, in principle, be used to isolate any cell subpopulation provided it has a fluorescein-labeled ligand on its surface. In this report the matrix was used to isolate viable purified fractions of mouse surface Ig-positive cells, Lyt1 cells, and mouse lymphocytes that bind the lectin soybean agglutinin. A preliminary experiment using the anti-FITC beads suggested that this technique can provide a fraction of cells enriched in antigen binding cells. Cell populations isolated by this technique retain their ability to respond to in vitro mitogen stimulation, as well as their ability to be maintained in cell culture following fractionation. Additional experiments using a column consisting of goat anti-rabbit Ig antibody coupled to the same support material are also reported.

Animals↗
PubMed1980

Development of naked growing mouse oocytes in vitro.

Half grown oocytes were released from follicles of 7-day-old mouse ovaries during overnight culture. Naked oocytes free of attached follicular cells were cultured in MEM plus 10% fetal calf serum over the developing monolayer of ovarian cells. Oocytes increased in diameter for a period of at least a week at 1.6 micron per day, or 70% of the in vivo growth rate. The ultrastructure of cytoplasmic organelles in cultured growing oocytes was normal. During the second week, about 35% underwent spontaneous fragmentation, and at least 10-20% resumed meiotic maturation. We conclude that a significant fraction of naked oocytes reached a functional state comparable to that of normal full grown oocytes at a rate approaching the in vivo rate. Free oocytes with attached cells grew to a larger average diameter than naked oocytes, and incorporated 3H-leucine 75% more rapidly. Naked oocytes cultured in the absence of ovarian cells did not grow, and died when pyruvate was omitted from the medium. Naked oocytes did not grow when cultured over primary mouse fibroblasts, L-cells, CHO cells, or hepatoma cells. Naked oocytes separated from the monolayer of ovarian cells by a 0.7 mm layer of agar grew at 60% of the rate of control oocytes.

Animals↗
PubMed1977

In vitro culture of growing mouse oocytes.

A method is described for in vitro culture of naked growing mouse oocytes for at least four days. Tests for metabolic function indicate that the oocytes increase in volume, accumulate glucose-6-phosphate dehydrogenase, and maintain a steady level of 3H-uridine and 3H-leucine incorporation.

Animals↗
PubMed1976

Stability of RNA synthesized by the mouse oocyte during its major growth phase.

The RNA of growing mouse oocytes and ovulated ova was labeled by injection of a solution containing tritiated uridine into the ovarian bursa. The time course of incorporation into RNA by oocytes was followed by analysis of alkali-labile acid insoluble radioactivity and by autoradiography. The results show that most of the incorporation into RNA by growing oocytes takes place within one day of bursal injection of the precursor, reflecting the rapid fall of label in the acid soluble precursor pool. The RNA of growing oocytes of all sizes is unusually stable, at least 80% of the labeled RNA present two days after bursal injection being retained until ovulation 10 to 20 days later. The fraction of heterogeneous RNA in labeled RNA of ova was estimated as 20% by sucrose gradient analysis. It is likely that egg RNA is synthesized primarily during the period of oocyte growth one to three weeks before ovulation.

Animals↗
PubMed1976

The effect of 5-bromodeoxyuridine on cell division and differentiation of preimplantation mouse embryos.

Mouse embryos exposed to concentrations of 5-bromodeoxyuridine (BUdR) ranging from 0-01 to 1-0 mug/ml in vitro for two days from the 8-cell stage exhibit a concentration-dependent decrease in the frequency of normal blastocysts and decrease in average cell number per embryo. A 20-h exposure was adequate to achieve the full BUdR response. Both effects were eliminated in the presence of excess thymidine. Autoradiographs demonstrated that BUdR[3H] was incorporated into DNA during the first and second day of culture. Thus, BUdR appears to act through incorporation into DNA; and, in this system, cell division is at least as sensitive to BUdR as is differentiation.

Animals↗
PubMedDate not supplied

[Effect of vitamin A in significant doses on incorporation of (14C) retinol, acceptor capacity of tRNA and activity of certain enzymes in tissues and plasma membranes of cells in the presence of Guerin's carcinoma].

In rats with Guerin's carcinoma the weight and size of the tumour is twice as low when significant doses of vitamin A are administered. Under these conditions the acceptor capacity of tRNA of the small intestine mucosa as well as the intensity of [14C] retinol incorporation into plasma membranes of its cells decrease essentially, whereas in the mucosa itself the radioactivity remains high. When studying the activity of alkaline phosphatase, amylase in the mucosa and arginase in the liver, a disproportion is found in changes in the enzymes activity on the surface of the small intestine mucosa and in the mucosa homogenate, that may be due to a change in the state of the cell membrane apparatus when the tumour is formed. Under the effect of significant doses of vitamin A there might occur thelysis of the tumour cell membranes, which results in the metabolism normalization.

Alkaline Phosphatase↗
PubMedDate not supplied

[Effects of vitamin A on formation of aminoacyl-tRNA].

The melting temperature and hyperchromia of intestine mucosa tRNA preparations and the effect of inactivating factors on aminoacyl-tRNA-synthetase activity were studied at the stage of hypovitaminosis and under deep A-avitaminosis. It is shown that in the aminoacylation reaction, aminoacyl-tRNA-synthetase is a component more sensitive to vitamin A deficiency.

Amino Acyl-tRNA Synthetases↗
PubMedDate not supplied

[Study of hydrolase activity of rat small intestine mucosa with vitamin A deficiency].

The activity of amylase, alkaline phosphatase and lipase in the pancreas, in the mucosa and on the surface of small intestine (turned out segments) was studied for elucidating the effect of vitamin A deficiency on the synthesis of the studied enzymes and their translocation to the surface of glycocalix cell membranes. The activity of amylase is established to increase in the homogenate of the pancreas, intestine mucosa and on the surface of cell membranes. The activity of alkaline phosphatase and lipase in the homogenate of small intestine mucosa and in the pancreas lowers. The results obtained evidence for a disturbance in the intestine digestive function with vitamin A deficiency, the may be connected with the damage of the mucosa membrane structures as well as with a disturbance in the biosynthesis of the protein playing a decisive role in formation of secretory products in cells.

Alkaline Phosphatase↗
PubMedDate not supplied

[On the potential protective properties of vitamin A in carcinogenesis].

The effect of massive doses of vitamin A was studied as applied to the tumor growth in rats with Guerin's carcinoma, protein biosynthesis in them and enzymic activity. It is established that intraperitoneal administration of vitamin A massive doses (the total quantity being 4000 000 and 2000 000 I.U.) in equal doses for 6 days decreases tumor sizes and weight, intensity of protein biosynthesis by the cell-free protein-synthetizing system of the small intestine mucosa, intensifies activity of retinylpalmitate hydrolase, decreases that of retinylpalmitate synthetase, increases the activity of alanine aminotransferase. The authors assume that under the effect of vitamin A massive doses the capacity of retinol-binding protein transporting vitamin A is exhausted, the latter being transported in a cell by lipoproteids, which causes the cell membrane lysis.

Animals↗