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Biomedical subjects

S Shirato

Publications and source records attributed to S Shirato.

85 records · Page 5Linked to original sources

Fermentation studies with Streptomyces griseus. II. Synthetic media for the production of streptomycin.

Synthetic media for streptomycin fermentation were studied to determine which media gave highest yields of streptomycin. The effect of salts on streptomycin production by Streptomyces griseus was examined, and a suitable combination of salts was established in a glucose-casein medium. This medium yielded 3,000 mug/ml of the antibiotic with an inoculum of 1.6%. Substitution of amino acids for casein was examined. Of 17 amino acids tested, best results were obtaind with sodium aspartate. Substitution of ammonium salts was tried, and an excellent streptomycin yield was obtained with a medium containing ammonium citrate.

Amino Acids↗

Fermentation studies with Streptomyces griseus. I. Carbohydrate sources for the production of protease and streptomycin.

The effects of four carbon sources and inorganic phosphate on the production of streptomycin and protease by a strain of Streptomyces griseus were studied. Protease production was increased in fermentations with comparatively rapid consumption of carbohydrate, and streptomycin was produced under conditions of moderately slow consumption. Starch was consumed more rapidly than glucose, and, in fermentations with starch as a carbon source, good yields of protease were associated with poor yields of streptomycin. The effect of the concentration of inorganic phosphate varied with the sugar source; the rate of consumption of glucose or fructose increased with the addition of inorganic phosphate, and the utilization of starch or maltose was not affected.

Carbohydrate Metabolism↗

The Gly367Arg mutation in the myocilin gene causes adult-onset primary open-angle glaucoma.

PURPOSE: To present the phenotype of a family whose members showed the Gly367Arg mutation in the myocilin gene and developed primary open-angle glaucoma (POAG). METHODS: The proband developed POAG when she was 45 years old. Examination of the myocilin gene revealed that the patient had a mutation causing amino-acid change (Gly367Arg) in the myocilin gene. The available family members were given clinical and genetic examinations. RESULTS: Eight members of this family carried the same mutation. The age of disease onset of POAG in these patients with the mutation averaged 36.7 years. Four young members with the mutation, with an average age of 20.8 years, had not yet developed POAG. CONCLUSION: The Gly367Arg mutation of the myocilin gene in the pedigree causes the development of POAG in adulthood.

Adult↗

Ocular tissue concentrations of mitomycin C with variable dose and duration of application time in rabbits.

We measured mitomycin C (MMC) concentrations in ocular tissues in rabbits with variable dose (0.1, 0.2, or 0.4 mg) and duration of application time (1, 3, or 5 minutes) of MMC using high-performance liquid chromatography. Mitomycin C concentrations at the administered site after single subconjunctival application of MMC and after irrigation showed significant correlation with dose and duration of time of application. By multiple regression analysis, MMC concentrations (microg/g) at the conjunctiva were described as -6.73 + 67.4 x Dose (mg) + 1.66 x Time (minutes) (R2 0.65); at the sclera, -1.85 + 38.2 x Dose + 0.927 x Time (R2 0.63); at the cornea, -0.727 + 8.44 x Dose (R2 0.46). With a 0.2-mg MMC dose, in all three application times (1, 3, or 5 minutes), MMC concentrations in the conjunctiva at the administered quadrant were three times higher than in the neighboring quadrants and 6 to 7 times higher than in the opposite quadrant. In the sclera, MMC concentrations were 3.5 times higher than in the neighboring sites and over 8 to 9 times higher than in the opposite site. In the cornea, MMC concentrations were 2 to 3 times higher than in the neighboring sites and opposite site. In the iris-ciliary body, MMC concentrations were 0.61 microg/g at the administered site with 0.2 mg for 3-minute application, 2 times higher than in neighboring sites, and 2 times higher than in opposite sites.

Animals↗

Clinical phenotype of a Japanese family with primary open angle glaucoma caused by a Pro370Leu mutation in the MYOC/TIGR gene.

PURPOSE: To present the phenotype of two patients with primary open angle glaucoma (POAG) caused by a mutation of the myocilin/trabecular meshwork-inducible glucocorticoid response (MYOC/TIGR) gene. METHODS: Complete ocular examinations were performed on the 13-year-old proband, her father, mother, and sister. DNA analysis was performed to detect the mutant gene. RESULTS: The proband and her father were found to have a mutation of the MYOC/TIGR gene. Both patients carried a heterozygous mutation in the 1,109th nucleotide, which corresponds to the 370th amino acid residue of the MYOC/TIGR gene. The clinical characteristics of both patients were: (1) development of POAG at an early age, (2) high peaks of intraocular pressure. and (3) poor response to medical treatment. CONCLUSIONS: The phenotype of these patients with a mutation of the MYOC/TIGR gene agreed with reports of other patients with mutations at other loci in this gene. The discovery of the MYOC/TIGR gene not only makes early detection of glaucoma possible, but also presents a new direction for investigating the pathogenesis of glaucoma.

Adolescent↗

The relationship between visual disability and visual scores in patients with retinitis pigmentosa.

PURPOSE: To evaluate the relationship between visual disability and visual scores in patients with retinitis pigmentosa. METHODS: The relationship between visual disability and visual scores (visual acuity and visual field) was investigated in 93 patients with retinitis pigmentosa. The visual disability of each patient was evaluated using a questionnaire (a total of 35 questions, in 7 sections, regarding daily life). The reproducibility and validity of the data obtained by the questionnaire had been established by a similar investigation in glaucoma patients. Mean (+/-SD) age of patients was 52.6 +/- 15.1 years, the mean visual acuity of the logarithm of the minimum angle of resolution (log10MAR) was 0.5 +/- 0.4, and the mean deviation of visual field with the Humphrey Field Analyzer program 30-2 was -22.0 +/- 10.9 dB. RESULTS: The visual acuity of log10MAR in the better eye (r = 0.66 to 0.81) and the mean sensitivity within the central 10 degrees of the visual field (r = -0.76 to -0.62) had a definite relationship to the visual disability index of each section and their sum (P < .0001). This relationship was also confirmed in multiple regression analysis, which showed a high correlation coefficient (R2 = 0.57 to 0.77, P < .0001). CONCLUSIONS: The retinal sensitivity within the central 10 degrees and the visual acuity of log10MAR in the better eye had a significant influence on a patient's daily life. We suggest that in patients with retinitis pigmentosa, visual disability in daily life can be precisely evaluated with the retinal sensitivity within the central 10 degrees and the visual acuity in the logarithm of the minimum angle of resolution in the better eye.

Female↗

Comparison of diclofenac and fluorometholone in preventing cystoid macular edema after small incision cataract surgery: a multicentered prospective trial.

PURPOSE: To compare a nonsteroidal topical solution (0.1% diclofenac) to a steroidal topical solution (0.1% fluorometholone) in preventing cystoid macular edema (CME) and disruption of the blood-aqueous barrier. METHODS: A multicentered, prospective clinical trial was performed on eyes undergoing phacoemulsification followed by implantation of a foldable acrylic intraocular lens by the envelope technique. The presence and degree of cystoid macula edema (CME) was determined by fluorescein angiography. A breakdown of the blood-aqueous barrier was determined by laser flare-cell photometry. RESULTS: Five weeks after surgery, CME was present in 3 of 53 eyes (5.7%) receiving diclofenac and in 29 of 53 eyes (54.7%) receiving fluorometholone. This difference was statistically significant (P < .001). The amount of flare in the anterior chamber at 3 days, 1, 2, 5, and 8 weeks after surgery was also significantly lower (P < .01-P < .001) in the diclofenac group. The degree of flare at 3 days, 1, 2, 5, and 8 weeks after surgery was significantly higher in eyes with CME (P < .001). CONCLUSIONS: These findings suggest that diclofenac effectively prevents CME following cataract surgery and that CME is closely related to the breakdown of the blood-aqueous barrier.

Aged↗

Influence of carteolol and timolol on IOP an visual fields in glaucoma: a multi-center, double-masked, prospective study.

The influences of Carteolol and Timolol eye drops on intraocular pressure (IOP) and visual fields were compared in a multi-center, double-masked, prospective study. Two-hundred and forty eyes of 120 patients were initially included in the study, and 142 eyes of 72 patients fulfilled all the criteria for final statistical analysis. Both drugs significantly reduced IOP. The visual fields in both treatment groups did not change during one year of treatment. In both groups some patients improved slightly, and others deteriorated slightly. This indicates that locally applied beta-blockers may efficiently stop further progression of visual field defects in cases with increased IOP and early visual field damage. There was no difference between Carteolol and Timolol in this regard. The side effects were minimal, and there were no differences in their frequency or intensity in the two treatment groups.

Adolescent↗