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Biomedical subjects

S Hayasaka

Publications and source records attributed to S Hayasaka.

At least 235 records · Page 13Linked to original sources
PubMed1986

Focal chorioretinal atrophic lesions in patients treated with hemodialysis.

Five patients treated with hemodialysis had focal chorioretinal atrophic lesions. These lesions had not been noted before the hemodialysis treatment. Although the lesions resembled those of ocular toxoplasmosis and histoplasmosis, serum titers and skin reactions for those organisms were negative or within the normal range. Focal retinochoroidal lesions in patients receiving hemodialysis may indicate a possible sign of infection.

Adult↗
PubMed1986

Irregular macular pigmentation in patients treated with hemodialysis.

We examined 3 patients treated with hemodialysis who showed irregular macular pigmentation. They previously had had renal retinopathy with star-shaped exudates and shallow retinal detachment at the macula. It is possible that the irregular macular pigmentation in these patients may be scar stage or pigment epithelial changes of the renal retinopathy and choroidopathy.

Adult↗
PubMed1986

Localized chorioretinal degeneration in patients receiving hemodialysis.

We examined 55 patients treated with hemodialysis and found 10 who showed localized chorioretinal degeneration, probably caused by a choroidal vascular disturbance. These changes manifested as a triangular patch, peripapillary or segmental chorioretinal lesions, and localized pigment epithelial alterations on fluorescein angiography. It is possible that chorioretinal complications may be a problem in patients receiving hemodialysis.

Adult↗
PubMed1986

Orbitocranial fibrous dysplasia. A case report.

A 14-year-old girl had right proptosis, facial asymmetry, and gradual increasing poor vision. X-ray findings showed sclerosis in the sphenoidal bone and the base of the skull. Partial excision of dysplastic bone, decompression of the optic canal, orbit, and superior orbital fissure, and reconstruction of the upper orbital wall were performed one year later. Histopathologic examinations disclosed fibrous dysplasia of sclerotic form. There has been no progression of the disease since the surgery, and good cosmetic and visual results had been achieved.

Adolescent↗
PubMed1986

Hereditary congenital nystagmus. A Japanese pedigree.

A Japanese pedigree of congenital nystagmus compatible with an X-linked irregular dominant transmission is described. An absence of male-to-male transmission, and skipping of a generation were noted. Genetic counseling for congenital nystagmus is difficult because of the irregular pattern of inheritance.

Adult↗
PubMed1986

Effects of pindolol, befunolol and melanin treated with adrenergic beta-blocking agents on lysosomal enzymes in bovine ciliary body and iris in vitro.

We studied biochemically the effects of pindolol, befunolol and melanin treated with beta-blockers on lysosomal enzymes in the ammonium sulfate fraction of the bovine ciliary body and iris in vitro. Acid phosphatase, beta-D-glucuronidase and alpha-D-mannosidase were not inhibited by the beta-blockers. N-acetyl-beta-D-glucosaminidase and alpha-L-fucosidase activities were inhibited by pindolol and befunolol at high concentrations. After centrifugation of the enzyme fraction incubated with melanin, the enzyme activity in the supernatant decreased, possibly as a result of the affinity of lysosomal enzymes to melanin. When melanin was first treated with pindolol or befunolol, some lysosomal enzyme activities increased in the supernatant after removing the melanin, depending on the concentration of the beta-blocking agent. This increased activity may result from the loss of affinity of lysosomal enzymes to melanin caused by the beta-blocking agent.

Adrenergic beta-Antagonists↗
PubMed1986

Presence of tyrosinase activity in human ciliary body.

We examined tyrosinase activity in pigmented tissues from five human eyes. Tissue extract was prepared in cholate-phosphate buffer by homogenization, centrifugation, trypsin digestion and hydroxylapatite column chromatography. Tyrosinase activity was spectrophotometrically assayed as dopa (L-3,4-dihydroxylphenylalanine) oxidase activity. Tyrosinase activity was detected in the extracts of the ciliary body. Enzyme activity was inhibited by phenylthiourea but not by 3-iodo-tyrosine. We believe that our findings confirm the presence of tyrosinase activity in the human ciliary body.

Aged↗
PubMed1986

Effects of chlorpromazine-pretreated melanin on lysosomal acid phosphatase and N-acetyl-beta-D-glucosaminidase in bovine ciliary body and iris in vitro.

We studied biochemically the effect of chlorpromazine-pretreated melanin on lysosomal enzyme activities in the bovine ciliary body and iris in vitro. Melanin was prepared from the bovine ciliary body and iris by acid treatment. Acid phosphatase and N-acetyl-beta-D-glucosaminidase of the ciliary body and iris were used as lysosomal marker enzymes. After the enzyme solution was incubated with melanin, enzyme activity was reduced and protein content in the supernatant was decreased. When melanin was pretreated with chlorpromazine, both enzyme activity and protein content in the supernatant remained higher than after the incubation with melanin alone, depending on the concentration of chlorpromazine. Chlorpromazine itself seemed to have little effect on the acid phosphatase and N-acetyl-beta-D-glucosaminidase at the concentration used in the incubation mixture. The increased enzyme activity, therefore, may result from a loss of the enzyme affinity for melanin after chlorpromazine pretreatment. These findings were discussed with respect to the binding mechanism of lysosomal enzymes to melanin and possible effect of chlorpromazine on biochemical interaction between lysosomal enzymes and melanin in vivo.

Acetylglucosaminidase↗
PubMed1986

Lysosomal enzymes in tear fluids from patients with ocular diseases.

Lysosomal enzyme activities in the tear fluids were determined in patients with ocular diseases. Acid phosphatase, beta-D-glucuronidase, N-acetyl-beta-D-glucosaminidase, and beta-D-mannosidase activities were almost the same among the tear fluids from patients with myopia, rhegmatogenous retinal detachment, simple diabetic retinopathy and pigmentary retinal dystrophy. In contrast, the activities were lower in the affected eyes of patients with herpetic keratitis and vernal conjunctivitis than in the fellow normal eyes. It is possible that the lysosomal enzyme activities in the tears may be closely related to the condition of the external eye disease.

Adolescent↗
PubMed1986

Acidic lens-protein degrading activity in bovine ciliary body. III. Lens crystallin degradation by fractions A and B.

We studied the in vitro digestion of lens crystallin by two fractions (Fractions A and B) of acidic lens-protein degrading activity from the bovine ciliary body. With whole lens crystallin as substrate, Fraction A degraded beta L-crystallin most significantly, and beta H-, gamma-, and alpha-crystallins moderately. Fraction B degraded alpha-crystallin most significantly, beta H- and beta L-crystallins moderately, and gamma-crystallin slightly. Insoluble protein was most resistant to digestion by Fractions A and B. Crystallins from the lens cortex and nucleus were degraded in the same manner as those from the whole lens.

Acids↗
PubMed1985

Progressive cone dystrophy associated with low alpha-L-fucosidase activity in serum and leukocytes.

The enzyme activities of acid phosphatase, beta-glucuronidase, N-acetyl-beta-D-glucosaminidase, and alpha-D-mannosidase were not significantly different in patients with myopia, retinal detachment, hereditary macular dystrophy, and unusual progressive cone dystrophy. alpha-L-Fucosidase activity in sera was lower in three patients with myopia and in two patients with unusual progressive cone dystrophy than in most of the others. Leukocytic alpha-L-fucosidase activity was lower in those with unusual progressive cone dystrophy. The two unrelated patients with unusual progressive cone dystrophy had slowly deteriorating visual acuity, color vision, and photopic electroretinographic responses, but ophthalmoscopically normal fundi and noncontributory family histories.

Adolescent↗
PubMed1985

Aminoglycoside antibiotics and lysosomal enzymes of human tears.

We examined biochemically the effect of six aminoglycoside antibiotics on the activity of lysozyme, acid phosphatase, and N-acetyl-beta-D-glucosaminidase in human tears. All six antibiotics strongly inhibited lysozyme activity, the degree of inhibition depending on the dose administered. Except for bekanamycin, antibiotics had little effect on the activity of acid phosphatase or N-acetyl-beta-D-glucosaminidase. The nature of the inhibition was competitive. Other kinds of antibiotics, such as sulbenicillin or erythromycin, had no inhibitory effect on lysozyme, acid phosphatase, or N-acetyl-beta-D-glucosaminidase. These results suggested that the inhibition of lysozyme by aminoglycosides is specific and that the decreased effectiveness of a protective system against bacterial infection in the eye is highly possible when aminoglycoside antibiotics are used without prior sensitivity testing.

Acetylglucosaminidase↗
PubMed1985

Tyrosinase activity in the uveal tissue of the adult bovine eye.

Tyrosinase activity in crude extracts from various tissues of the adult bovine eye was examined biochemically. Enzyme activity was measured by using L-3,4-dihydroxyphenylalanine (L-DOPA) as substrate and determining colorimetrically by an increase in absorbancy at 400 or 475 nm. Tyrosinase activity was found in the ciliary body, iris, and choroid with the ciliary body having the highest enzyme activity. The enzyme was 1324-fold purified from the crude extract of the ciliary body by ammonium sulfate fractionation, trypsin digestion, followed by chromatography on Sephacryl S-200, hydroxylapatite, and DEAE-cellulose columns. The apparent Km value for L-DOPA was 0.2 mM and the molecular weight of the enzyme was estimated to be 70000 by gel method. The enzyme activity was markedly reduced by phenylthiourea and diethyldithiocarbamate, specific inhibitors of tyrosinase.

Animals↗
PubMed1985

Acidic lens protein degrading activity in bovine ciliary body.

Biochemical studies of acidic lens protein degrading activity in the bovine ciliary body were performed. The activity showed two peaks, Fractions A and B, on Sephadex G-75 column chromatography. Fraction A contained cathepsin D and thiol proteinase activities and was inhibited by pepstatin and leupeptin. Fraction B contained thiol proteinase activity and was inhibited by leupeptin. The proportion of peptide released from the lens protein by Fractions A and B was higher than those from bovine serum albumin and casein. Lens protein may be a good assay substrate for cathepsin D and lysosomal thiol proteinase in the ciliary body.

Animals↗
PubMed1985

Lysosomal enzymes in human tear fluid collected by filter paper strips.

Protein concentrations and lysosomal enzyme activities in tear fluid collected by filter paper strips were studied. The magnitude of the wetted area on the filter paper did not affect the apparent protein concentration in the tear fluid. Lysosomal enzyme activities in tear fluid were higher than those in serum. The pH and enzyme activity curves in tear fluid were similar to those in serum. The optimal pH of acid phosphatase, beta-D-glucuronidase, N-acetyl-beta-D-glucosaminidase, alpha-L-fucosidase and alpha-D-mannosidase in tear fluid were determined.

Acetylglucosaminidase↗
PubMed1985

Lipaemia retinalis in a 29-day-old infant with type 1 hyperlipoproteinaemia.

A 29-day-old infant born of consanguineous parents had type 1 hyperlipoproteinaemia associated with lipaemia retinalis. Biochemical analyses disclosed hypertriglyceridaemia, hyperchylomicronaemia, and lipoprotein lipase deficiency. Ophthalmoscopically all retinal vessels had the creamy appearance of lipaemia retinalis. The plasma lipoprotein levels and fundus condition became normal after her ingestion of fat was limited. To our knowledge this is the youngest patient reported with type 1 hyperlipoproteinaemia associated with lipaemia retinalis.

Dietary Fats↗
PubMed1985

Clinical trials of vitamin B6 and proline supplementation for gyrate atrophy of the choroid and retina.

Five patients with gyrate atrophy of the choroid and retina were examined ophthalmologically, especially ophthalmoscopically, to evaluate trials of vitamin B6 (pyridoxine) or supplementary proline. The oral administration of vitamin B6 was tried in two patients. The vitamin did not alter the serum ornithine level and the progression of chorioretinal atrophy in one patient (case 2). Despite a reduced serum ornithine level following vitamin B6 administration, chorioretinal atrophy progressed gradually in another patient (case 3). Supplementary proline was tried in four patients. Despite the supplementation the serum proline level did not increase, and the chorioretinal atrophy progressed in one patient (case 2) who received both vitamin B6 and proline. Supplementary proline minimised the progression of gyrate atrophy in the youngest patient (case 1) and halted the progression in two others (cases 4 and 5). Supplementary proline may possibly lessen the progression of chorioretinal lesions in gyrate atrophy.

Adolescent↗