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Biomedical subjects

Y Sasamoto

Publications and source records attributed to Y Sasamoto.

47 records · Page 3Linked to original sources
PubMed1991

Topical application of ciclosporin ophthalmic solution containing alpha-cyclodextrin in experimental uveitis.

Ciclosporin (CS) has been shown to be a potent immunosuppressive drug. However, systemic administration of CS has been limited because of its unfavourable side effects. Thus, our attention has been focused on a topical application of CS for ophthalmic diseases. In this study, we examined the influence of a topical application of CS on experimentally induced ocular inflammation. CS was prepared by a new drug delivery system, with alpha-cyclodextrin (CD) as a solvent. Topical 0.075% CD-CS reduced ocular inflammation of rabbits induced by intravitreal injection of bovine serum albumin. The magnitude of efficacy of topical 0.075% CD-CS fell within the same level as that of topical 0.02% fluorometholone. However, the topical CD-CS showed no effect on experimental autoimmune uveitis in rats which had been induced by S-antigen or interphotoreceptor retinoid-binding protein. These findings indicate that the topical CD-CS is effective on anterior uveitis.

Administration, Topical↗
PubMed1991

Trials of vaccination against experimental autoimmune uveoretinitis with a T-cell receptor peptide.

T lymphocytes which mediate several experimental autoimmune diseases, including encephalomyelitis (EAE) and uveoretinitis (EAU) in Lewis rats, preferentially utilize V beta 8 gene product in their receptor. Vaccination against a V beta 8.2-derived peptide was reported to inhibit EAE induction and we report here on the effect of vaccination with this peptide on the development of EAU. Experimental rats were pretreated with the V beta 8.2 peptide, emulsified in adjuvant (CFA), whereas control animals were untreated or injected with saline in CFA. Rats of all groups were immunized 30 or 40 days later with the immunopathogenic antigen, emulsified in Mycobacterium-enriched CFA. Vaccination with CFA emulsions containing either the V beta 8.2 peptide or saline, remarkably inhibited the development of the tested diseases, as compared to the untreated controls. Vaccination with the V beta 8.2 peptide had variable effects in this study on disease development: it inhibited the S-antigen-induced EAU more than did treatment with CFA in four out of six experiments, had a similar effect to that of CFA in one experiment and enhanced the disease in another experiment. Conversely, vaccination with the V beta 8.2 peptide slightly enhanced the EAU induced by the interphotoreceptor retinoid-binding protein (IRBP), or its dominant determinant, in three of four experiments and had no apparent effect in the fourth experiment. In addition, we could not reproduce the reported protective effect of vaccination with the V beta 8.2 peptide against induction of EAE. Vaccination with the V beta 8.2 peptide also had no clear effect on the development of humoral or cellular immune responses against S-antigen.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

[Close association of Streptococcus sanguis and Behçet's disease].

The oral flora of patients with Behçet's disease was investigated and compared to that of controls. The proportion of Streptococcus (S.) sanguis in the flora of patients with this disease was always higher than that of healthy controls. It is noteworthy that serotypes of S. sanguis in the oral flora of patients were different from controls. Immune responses against S. sanguis were also examined in the patients. Antibody titers against S. sanguis were higher in patients than in controls. Furthermore, the patients showed significantly increased skin reactivity to S. sanguis. These results suggest that uncommon serotypes of S. sanguis play an important role in the pathogenesis of Behçet's disease.

Adolescent↗
PubMed1990

Studies on corticosteroid therapy in Vogt-Koyanagi-Harada disease.

We evaluated the significance of corticosteroid therapy on 47 new patients with Vogt-Koyanagi-Harada disease examined in the Uveitis Survey Clinic of the Hokkaido University Hospital. All patients were treated with topical corticosteroids, with or without systemic corticosteroids. 18 patients received systemic corticosteroid as pulse therapy, 20 patients received high-dose corticosteroid starting with prednisolone 200 mg, 2 patients received conventional-dose corticosteroid and 7 patients received no systemic corticosteroid therapy. When we evaluated the results 6 months after the initiation of treatment, anterior chamber inflammation was significantly less in patients with pulse and high-dose corticosteroid therapy than in those without systemic corticosteroid therapy. Furthermore, final visual acuity was significantly better in patients with pulse and high-dose corticosteroid than in those without them. However, there was no significant difference between patients with pulse therapy and those with high-dose corticosteroid therapy. The findings are in support of systemic corticosteroid therapy (pulse and high-dose) in the treatment of Vogt-Koyanagi-Harada disease.

Administration, Topical↗
PubMed1990

[Studies on delayed skin reactivity to streptococci in Behçet's disease].

Delayed type hypersensitivity of patients with Behçet's disease was investigated by intradermal skin test and prick test, using various inactivated microorganisms as antigens. In the intradermal skin test, 13 patients showed significantly increased skin reactivity to E. faecalis, compared with 5 normal controls. No significant differences were observed between these two groups in terms of reaction to S. pyogenes. Prick test was performed in 11 patients and 6 controls, using S. pyogenes, S. sanguis, S. salivarius and E. faecalis as antigens. It was shown that patients with this disease had significantly greater skin reactions to crude cell wall antigens, as well as to whole cell antigens of these streptococci than the controls. The antigenicity of streptococci seemed to be present mainly in the cell wall fragment, and these streptococci seemed to have cross reactivity with each other. These results suggest that streptococci may have some significant role in the immunopathogenesis of this disease.

Adult↗
PubMed1990

[Immunological analysis of Streptococcus sanguis antigens].

The exact cause of Behçet's disease is still unknown. Recently, advanced bacterial studies revealed that Behçet's disease was related to Streptococcus (S.) sanguis. However, the antigenicity of S. sanguis has not been fully studied. In this study, we clarified the antigenicity of S. sanguis. We made S. sanguis antigens: Mechanical Braun Extract (MBE) and Crude Cell Wall (CCW) from the whole cells, Membrane Fraction (MF) and Cytoplasmic Fraction (CF) from MBE, Cell Wall Fragment (CWF) and Lipoteichoic acid (LTA) from MBE. We found that the major antigenicity of S. sanguis was present in CF by use of the Ouchterlony method and the ELISA method. However, apart from S. pyogenes, we could not recognize a common antigenicity among S. sanguis and several other antigens, such as S-Ag, IRBP, retinal soluble fraction, retinal insoluble fraction and Enterococcus faecalis, by the Ouchterlony method. Since we have clarified the antigenicity of S. sanguis in this study, we can now perform detailed examinations with samples from patients with Behçet's disease for S. sanguis antigens.

Animals↗
PubMedDate not supplied

Pararectal rhabdomyosarcoma: report of a case.

Primary rhabdomyosarcoma of the alimentary tract is extremely rare, only 11 cases have been reported in the literature. Long-term survival in adults may be possible if the tumor is detected at an early stage even though it is asymptomatic. This highly malignant tumor can be treated by surgical excision, chemotherapy, and irradiation. A 12th case--of stage 1, pararectal, rhabdomyosarcoma--is reported.

Aged↗
PubMedDate not supplied

Prolonged survival of reconstituted skin grafts without immunosuppression.

Reconstituted skin composed of a cultured allogeneic epithelial sheet (CAES) and a cultured allogeneic dermis (CAD) was evaluated in a rat model to determine whether it could survive for a prolonged period without immunosuppression. Additionally, free CAD grafts were evaluated for their suitability as dermal substitutes. Male Buffalo rats were used as donors and male Lewis rats as recipients. Split-thickness skin obtained from Buffalo rats was separated into epidermis and dermis by means of Dispase II enzyme. The epidermal layers were minced and trypsinized. Then dispersed single keratinocytes were inoculated onto a irradiated 3T3 cell feeder layer. After a suitable period, a confluent cultured keratinocyte layer was detached and provided CAES grafts. Cultured allogeneic dermis grafts were prepared from cultures of the dermal component. Cultured allogeneic dermis grafts, covered by split thickness isografts (STIG) or local skin flaps, became revascularized at a rate of 94.6% and 90.9%, respectively, 7 days after grafting. However, only 25% of CAD grafts covered by synthetic materials became vascularized. Four types of wound coverage were compared including: (1) CAES grafts, (2) CAES over CAD grafts, (3) split-thickness isografts, and (4) STIG over CAD grafts. In groups 2 and 4, CAD grafts were applied 7 days before CAES grafts or STIG. Grafts of groups 1 and 2 were successful in only 36.7% and 31.1% of the animals and resulted in a high rate of wound contracture--72.4%, 66.7%, respectively. On the other hand, in groups 3 and 4, higher average rates of revascularization (92.0% and 88.3%) and lower rates of wound contracture (25.4% and 24.2%) were obtained.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗