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Biomedical subjects

C Sato

Publications and source records attributed to C Sato.

At least 379 records · Page 21Linked to original sources
PubMed1978

Chromosomal anomalies of preimplantation rabbit blastocysts and human artificial abortuses in relation to maternal age.

It is well established that in man there is a higher frequency of chromosomally and phenotypically abnormal offspring and a decline in fertility as maternal age increases. This paper describes preliminary work on some chromosomal aspects of 5- and 6-day old preimplantation rabbit embryos, with attention to maternal age dependence of chromosome anomalies. Chromosome preparations were made by a modification of the method of Shaver and Carr (1967). Two trisomic blastocysts were observed among 50 embryos examined from 10 does of 40 to 52 months of age, that is, 45XY with an extra submetacentric chromosome and 45XX with an extra acrocentric chromosome. In man, three trisomies (47XX, G+, 47XX, D+, and 47XY, G+), one monosomy (45X or 45XX, C-) and one double trisomy (48XY, C+, E+ or 48XXY, E+) were karyotyped out of 32 early induced abortuses from women older than 40. Among the 22, induced abortuses analyzed from women between 35 and 39, one trisomic embryo of 47XY, G+ was observed.

Abortion, Induced↗
PubMed1977

Translocation of hyaluronic acid in cell surface of cultured mammalian cells after x-irradiation and its recovery by added adenosine triphosphate.

To investigate the mechanism of radiation-induced decrease in cell electrophoretic mobility and its recovery by added adenosine triphosphate, specific enzymes and buffer solutions of different ionic strength were utilized. Decrease in the mobility of irradiated cells was detected only with the buffer solution of ionic strengths higher than 0.100. In this range of ionic strengths, removal of hyaluronic acid from cell surface by hyaluronidase had no effect on the electrophoretic mobility of irradiated cells, while the enzyme treatment resulted in 27% mobility reduction in non-irradiated cells. The removal of sialic acid and chondroitin sulfate by their specific enzymes resulted in the similar decrease in mobility either in irradiated and non-irradiated cells. These results suggest that the X-ray induced translocation of hyaluronic acid from the peripheral zone of O--7.5 A into the deeper zone of about 10--17 A, if we use the Debye-Hückel's thickness of ion atmosphere for an approximate estimate of effective depth of electrokinetic plane of shear. Hyaluronic acid reappeared to the peripheral zone by the subsequent incubation after small dose irradiation, or by the addition of 1 mM adenosine triphosphate with Ca2+.

Adenosine Triphosphate↗
PubMed1977

Decrease and recovery in cell surface charge induced by anesthetics.

We applied cell electrophoresis to detect the effect of anesthetics on membrane, and clarified the concentration - effect relationship and the term of reversibility. The cell electrophoretic mobility of rat erythrocytes decreased with time of incubation with intravenous anesthetics (thiopental or droperidol) at clinical concentrations and reached a minimum value of 25% reduction in 30 min. The effect changed gradually in the concentration range of 0.5-1000 microgram/ml of thiopental, and changed markedly with 0.3-1 microgram/ml of droperidol. Washing out of the anesthetics and subsequent incubation in serum-containing medium resulted in the complete recovery in the mobility when 5 microgram/ml thiopental or 1 microgram/ml droperidol was used. With high concentration of thiopental (100 microgram/ml) or droperidol (10 microgram/ml, however, unrecovered fraction of cells increased with time of treatment. The critical time for retaining the reversibility was about 2 hr.

Anesthetics↗
PubMed1976

Small amount of concanavalin A modifies radiation-induced alteration in cell-surface charge depending on its binding condition.

Cell electrophoretic mobility of cultured melanoma cells or rat erythrocytes decreased with time after X-irradiation. Addition of tetravalent concanavalin A or divalent succinyl-concanavalin A before (not after) irradiation, completely blocked the mobility reduction in greater concentrations than 5 mug/l. At 5 mug/l only 3.7 - 10(3) concanavalin A molecules bound to receptors per cell, while 4.18 - 10(7) molecules/cell bound at saturating concentrations. Preincubation with concanavalin A at 37 degrees C was effective even when the cells were treated with alpha-methylmannoside immediately after irradiation. At low temperature, however, concanavalin A was not effective despite a sufficient amount of bound 125I-labelled concanavalin A. Treatment with alpha-methylmannoside following the binding of concanavalin A at 37 degrees C before irradiation inhibited the concanavalin A effect depending on temperature. The residual amount of bound lectin could not account for the temperature dependence. The amount of sialic acid (the main charged substance) was not altered by X-irradiation with or without the lectin. Divalent succinyl-concanavalin A was also effective in blocking the radiation effect on electrophoretic mobility. These results seem to suggest that binding of a very small amount of concanavalin A without causing cell agglutination or clustering of its receptors, induces some alteration in the conformation of receptor glycoprotein, which blocks the internalization of acidic sugar residues by subsequent irradiation.

Animals↗
PubMed1975

The production of acidic polysaccharides by 5-bromodeoxyuridine-treated B16 mouse melanoma cells.

B16 melanoma cells were treated in culture with 5-bromo-2-deoxyuridine. The cell-associated and released proteoglycans and sialoglycopeptides were compared to those of control cultures treated with thymidine. The 5-bromo-2-deoxyuridine-treated cultures showed a marked reduction in the proportion of cell-associated proteoglycans and sialoglycopeptides, an increase in the synthesis of hyaluronic acid, the absence of high-molecular-weight chondroitin sulfate, and the presence of increased amounts of heparan sulfate in the media. In addition, the 5-bromo-2-deoxyuridine-treated cells had a higher DNA content and were larger than controls.

Animals↗
PubMed1975

Properties of acidic saccharides produced by B16 melanoma cells treated with 1-methyl-3-isobutylxanthine.

A cyclic nucleotide phosphodiesterase inhibitor, 1-methyl-3-isobutylxanthine, promoted the differentiation and maturation of B16 melanoma cells, phenomena associated with biological alterations in the surface properties of the cells. 1-Methyl-3-isobutylxanthien inhibited cell replication and increased the intracellular content of melanin and cyclic adenosine 3':5'-monophosphate. Significantly greater amounts of sialoglycoproteins were associated with 1-methyl-3-isobutylxanthine-treated cells. However, the total amount of [3H] glucosamine incorporated into anionic polysaccharide (both sialoglycopeptide and mucopolysaccharides) was not significantly changed.

2',3'-Cyclic-Nucleotide Phosphodiesterases↗