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Biomedical subjects

S Akiya

Publications and source records attributed to S Akiya.

At least 55 records · Page 3Linked to original sources
PubMed1984

Morphological study on glycosaminoglycans in the developing human vitreous.

The vascular and the avascular vitreous in 7th- and 8th-week human embryos and 9th-week fetuses were stained strongly by alcian blue, while marked decrease in staining by alcian blue was observed in 12th- and 13th-week human fetuses. The nature of alcian blue positive materials was identified as hyaluronic acid and chondroitin sulfate or dermatan sulfate by enzymatic digestion methods and the Scott-Dorling method. The results suggest that distinction between primary and secondary vitreous is difficult by classical histochemical techniques and electron microscopy, and that the vitreous glycosaminoglycans concentration seems to be high at 7th- and 8th-week embyonic stages and decreases at later fetal stages.

Chondroitin Sulfates↗
PubMed1984

Electron microscopic observation on the developing rabbit and human vitreous collagen fibrils by negative staining.

The vitreous fibrils of developing eyes of 3-day-old rabbits and 24th week human fetuses were examined by the negative staining method (phosphotungstic acid) electron microscopically. Fibrils about 10 nm in diameter and with no periodic striated pattern as well as adult ones were observed. Peculiar fibers were observed in both vitreous samples preserved at low temperature. Particularly, dimeric segment-long-spacing (SLS) aggregates and fibrous-long-spacing (FLS)-like aggregates were observed in 3-day-old rabbit vitreous. FLS-like aggregates showed a 125-nm light band and 50-nm dark band periodic pattern and seemed to be formed with 300-nm overlapping of dimeric SLS aggregates. The present results indicate that the developing vitreous could possibly form various types of collagen fiber under native conditions.

Adult↗
PubMed1983

Free amino acid concentrations in blood cells of two brothers with gyrate atrophy of the choroid and retina with hyperornithinaemia.

In this study we selected blood cells as accessible tissues and measured the free amino acid concentrations in erythrocytes, lymphocytes, and granulocytes of two patients with gyrate atrophy with hyperornithinaemia. We found that ornithine concentrations were elevated in blood cells, to different degrees depending on the type of cell, and that aspartic acid concentrations were low in erythrocytes. We also investigated the fluctuation of free amino acid concentrations in blood cells up to 24 h after the oral administration of ornithine. The ornithine concentration in the blood cells of the patients reached a peak 2 h after the oral administration, and remained high for at least 4 h, although after 2 h the concentration curves differed in the three types of cells.

Adult↗
PubMed1983

Amaurosis fugax for a long duration.

A 31-year-old Japanese male with unilateral bouts of transient visual loss lasting for variable periods of time has been observed. In spite of the prolonged duration of some of these attacks (the longest attack lasted 7 1/2 hours), the patient sustained a relatively small amount of functional damage to the retina. Although the exact mechanism underlying these bouts of transient visual loss remains unknown, a discussion of the possible causes of such episodes, as well as the reasons for the relative preservation of vision in spite of the length of these attacks, is included.

Adult↗