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Biomedical subjects

T Shiono

Publications and source records attributed to T Shiono.

At least 109 records · Page 6Linked to original sources
PubMed1983

Scanning electron microscopic study of Dacron degradation by ocular tissue extracts.

A scanning electron microscopic study showed that the surface of Dacron thread became significantly roughened after treatment with bovine iris-ciliary body extracts. The Dacron-degrading factor in the extract was nondialysable, heat-labile, and active at an acidic pH, suggesting that lysosomal enzymes may be a factor in this phenomenon. Bovine extracts from the iris, ciliary body, and sensory retina degraded the surface of Dacron most substantially, while the Dacron surface was moderately digested by extracts from the cornea and retinal pigment epithelium. Lenticular and choroidal extracts did not affect the Dacron surface. Possibly the factor that degrades Dacron may be different from that which affects nylon, and the Dacron suture may not be preferable for corneal surgery.

Animals↗
PubMed1983

Partial purification of cathepsin B in the bovine ciliary body and iris.

Cathepsin B in the bovine ciliary body and iris was studied biochemically using alpha-N-benzoyl-D,L-arginine-2-naphthylamide as substrate. The enzyme was purified to 210-fold from the autolyzed extract. The partially purified enzyme had a pH optimum at 6.0 and a molecular weight of 27,000. The apparent Km value for the substrate was 1.6 mM. The enzyme was activated by disodium ethylenediamine tetraacetate, cysteine, and dithiothreitol. The enzyme activity was inhibited strongly by leupeptin and partially by hyaluronate and chondroitin sulfate A.

Animals↗
PubMed1982

Lysosomal hyaluronidase in the subretinal fluid of patients with rhegmatogenous retinal detachments.

A biochemical analysis of 66 samples of subretinal fluid from patients with primary rhegmatogenous retinal detachment showed that 46 contained hyaluronic acid. Seventeen samples that did not contain hyaluronic acid disclosed hyaluronidase activity. Hyaluronidase activity in the subretinal fluid increased with the duration of the detachment but there was no correlation between enzyme activity and the age of the patient or the extent of the retinal detachment.

Adult↗
PubMed1982

A scanning electron microscopic study of nylon degradation by ocular tissue extracts.

A scanning electron microscopic study showed that the surface of the nylon used for corneoscleral wound closure was smooth, while the nylon suture thread used to fix the intraocular lens against the iris showed cracks and roughness on its surface. The surface of the nylon thread was also roughened after treatment with bovine iris-ciliary body extracts. The nylon-degrading factor in the extract was nondialyzable, heat-labile, active at acidic pH, and inhibited in part by leupeptin, suggesting that lysosomal enzymes may be a factor in this phenomenon. Of the bovine ocular tissues, ciliary body extract degraded the surface of the nylon thread most significantly. The nylon surface was moderately digested by the retinal pigment epithelial extract, and slightly eroded by the extracts from the iris, sensory retina, and choroid. Corneal and lenticular extracts did not affect the nylon surface. Nylon suture thread may be hydrolyzed by lysosomal enzymes and should be considered a late-degrading suture.

Animals↗
PubMed1982

Development of ornithine ketoacid aminotransferase in rabbit ocular tissues and liver.

Ornithine ketoacid aminotransferase in ocular tissues and liver was examined biochemically during the development of the rabbit. Developmental differences of specific enzyme activities were found between the ocular tissues and liver. The retina and choroid showed a relatively low activity after birth and an increased activity at 2.5 weeks, which remained high thereafter. The ciliary body and iris also showed a relatively low activity at birth and a rapid increase at 1 week, which remained so for about 14 weeks before a gradual decrease occurred. The enzyme in the liver exhibited a high activity at birth, which fell 1 week later. This was followed by a subsequent increase in enzyme activity that began at 7.5 weeks after birth. Enzyme activity peaked at 10 weeks, with a gradual diminution thereafter.

Aging↗
PubMed1982

Galactose cataract in Japanese patient.

A Japanese infant was found to have abdominal distension at the age of 4 weeks. A diagnosis of galactosemia was made at 8 weeks of age. Dietary management completely reversed the hepatosplenomegaly and ceased the progression of lens opacities. Mental retardation was also noted at a later age. We believe this is the first reported case of galactose cataract in Japan confirmed enzymatically.

Cataract↗
PubMed1981

Regional distribution of lysosomal enzymes in the retina and choroid of human eyes.

Regional distribution of lysosomal enzymes in the retina and choroid of human eyes was studied biochemically. Specific activities of acid phosphatase, cathepsin D, and arylsulfatase in the retina and choroid varied by area were also studied. The macular area showed the highest activities in comparison to other areas.

Acid Phosphatase↗
PubMed1981

Gyrate atrophy with hyperornithinaemia: different types of responsiveness to vitamin B6.

Three cases of Japanese patients with gyrate atrophy of the choroid and retina with hyperornithinaemia were studied clinically and biochemically. The types of disease differed in responsiveness to vitamin B6. In-vivo responsiveness to vitamin B6 was correlated with in-vitro data. It is suggested that the in-vitro examination of the influence of pyridoxal phosphate on ornithine ketoacid transaminase activity in cultured fibroblasts may be useful in ascertaining the efficacy of vitamin B6 treatment in gyrate atrophy. In addition the early development of the fundus lesions was observed in one case (case 1), and the ciliary body abnormality and chorioretinal atrophy were noted in another (case 3).

Adolescent↗