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Biomedical subjects

K Yazaki

Publications and source records attributed to K Yazaki.

104 records · Page 6Linked to original sources
PubMed1981

Electron microscopic studies of bacteriophage phi X174 intact and "eclipsing' particles, and the genome by the staining, and shadowing method.

Bacteriophage phi X174 particles were observed with a new method, a combination of staining and shadowing. Previously we used this technique to obtain clear visualization of the shape of cytoplasmic-polyhedrosis virus, especially the spikes of this particle. The phi X174 particle was observed to be an icosahedral particle of 25 nm in diameter carrying a spike at each vertex. The spike was a pentagonal frustum with a base of 9 nm and a height of 6 nm. When the phage was treated with calcium on the supporting film, the genome extruded from the particle. With the staining and shadowing method, it was clearly observed that the spike was the extruding channel of the genome. The genome extrusion occurred not only a single spike of the particle but also at two or more spikes. This implied that all 12 spikes of the particle had the same abilities to act as the channel of genome extrusion. The released genomes showed various thicknesses and shapes such as bending, looping, or branching, which were thought to reflect to compact form of DNA in a virus particle. The similarly between the spikes of bacteriophage phi X174 and those of cytoplasmic-polyhedrosis virus from silk worm was also discussed.

Bacteriophage phi X 174↗
PubMed1981

Effects of combination treatment with vitamins E and C on chloasma and pigmented contact dermatitis. A double blind controlled clinical trial.

A multi-clinical double-blind study on therapeutic effect of combination preparation of vitamins E and C was undertaken in comparison with single preparation of vitamin E and vitamin C in the treatment of chloasma or pigmented contact dermatitis (PCD). Combination treatment resulted in significantly better clinical improvement than vitamin C alone in both diseases. Objective data compiled from color difference measurements and color photographs revealed significantly better results with combination treatment in chloasma than vitamin C alone and, in PCD, than vitamin E or C alone. Differences in skin luminosity between hyperpigmented and normal areas significantly decreased in all three groups, with the combination group producing the most significant change. The total serum lipoperoxide level and its ratio to total serum lipids tended to decline in the combination group, and decreased significantly in vitamin E group. The sebum lipoperoxide level decreased significantly only in the combination group (EC).

Ascorbic Acid↗
PubMed1980

Isoelectric heterogenity of human chorionic gonadotropin: Presence of choriocarcinoma specific components.

Comparative clinical studies were carried out on the isoelectric heterogeneity of serum human chorionic gonadotropin (hCG) in normal pregnancy and trophoblastic disease by means of isoelectric focusing and radioimmunoassay. The immunoreactive hCG components in sera of women with normal pregnancy were composed of seven peaks with isoelectric points of 3.9, 4.1, 4.4, 4.7, 5.0, 5.8, and around 6.7. These same components were also observed in the sera of patients with hydatidform mole and invasive mole. However, in the sera of patients with choriocarcinoma, three additional components with isoelectric points of 3.2, 3.5, and 3.7 were observed in considerable amounts. The presence of those three specific components suggests the possibility to develop a new diagnostic procedure for the detection of choriocarcinoma.

Choriocarcinoma↗
PubMedDate not supplied

Levels of fructosyllysine in collagen are low compared with the loss of lysine in diabetic rats: involvement of oxidation in increased cross-linking.

1. It is thought that early glycation products on lysine residues of collagen are re-arranged to form collagen cross-links (advanced glycation end-products), which are increased in hyperglycaemia. We have previously reported that 4 week vitamin E supplementation in diabetic rats protected against the development of increased collagen cross-linking. In the present study we analysed early glycation products as fructosyllysine and amino acid content of tail tendon collagen in rats. 2. The amount of lysine residues in early collagen glycation products in diabetic rats was estimated to be less than 0.2 mol/mol type I collagen, whereas in the diabetic rats the loss of lysine residues was estimated to be 2.5 mol/mol. However, vitamin E supplementation protected against the loss of lysine residues without affecting early glycation products. 3. Thus, it is demonstrated that the amount of early collagen glycation products is quite small compared with the loss of lysine residues in diabetic rats and we suggest that the oxidative modification of lysine residues may be involved in the increased cross-linking observed in hyperglycaemia.

Amino Acids↗