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Biomedical subjects

S Ohno

Publications and source records attributed to S Ohno.

At least 487 records · Page 27Linked to original sources
PubMed1995

Differential targeting of protein kinase C and CaM kinase II signalings to vimentin.

Hydrolysis of inositol phospholipids by receptor stimulation activates two separate signaling pathways, one leading to the activation of protein kinase C (C kinase) via formation of diacylglycerol. The other is the inositol trisphosphate (IP3)/Ca2+ pathway and a major downstream kinase which is activated is Ca2+/calmodulin-dependent protein kinase II (CaM kinase II). To examine signaling pathways of C kinase and CaM kinase II to the cytoskeletal protein vimentin, we prepared monoclonal antibodies YT33 and MO82 which recognize the phosphorylation state of vimentin by C kinase and by CaM kinase II, respectively. Ectopic expression of constitutively active C kinase or CaM kinase II in primary cultured astrocytes by microinjection of the corresponding expression vectors induced phosphorylation of vimentin at each specific phosphorylation site, followed by reorganization of vimentin filament networks. In contrast, simultaneous activation of C kinase and CaM kinase II by inositol phospholipid hydrolysis with receptor stimulation led to an exclusive phosphorylation of vimentin at the CaM kinase II site, not at the site of C kinase. These results indicate that the intracellular targeting of C kinase and CaM kinase II signalings to vimentin is regulated separately, under physiological conditions.

Amino Acid Sequence↗
PubMed1995

Solution structure of cysteine-rich domain of protein kinase C alpha.

The three-dimensional structure of the second cysteine-rich domain of protein kinase C alpha (residues 95-159) was determined in aqueous solution by two-dimensional proton nuclear magnetic resonance and simulated annealing based calculations. On the basis of 687 distance constraints derived from assigned nuclear Overhauser effect (NOE) connectivities, a total of 10 converged structures were obtained from 40 runs of calculations. The atomic root-mean-square (RMS) difference about the mean coordinate positions (excluding residues 1-7, 16-17, 30-34, and 55-65) is 0.55 A for backbone atoms (N, C alpha, C') and 1.07 A for all non-hydrogen atoms. The molecular scaffold is maintained by triple-stranded and double-stranded twisted beta-sheets packed against an alpha-helix and two independent zincs are coordinated by His8, Cys38, Cys41, Cys57 and Cys21, Cys24, His46, Cys49, respectively. It should be noted that the metal ligands from the two sites are interleaved and this is thought to be a new structural motif of a zinc finger domain. Based on the resultant structure, we propose an interaction site of the cysteine-rich domain of protein kinase C with diacylglycerols and phorbol esters.

Amino Acid Sequence↗
PubMed1995

Comparison of intraocular lenses from the standpoint of postoperative glare disability.

Although implantation of an intraocular lens provides excellent postoperative visual acuity, some factors such as disability glare have attached importance to qualitative evaluation of the visual function of artificial pseudophakia. In order to find out which factor most greatly contributed to glare disability, four types of intraocular lens, convexplano, biconvex anterior more curved, posterior more curved, and equiconvex, were prospectively implanted. The patients were 21 men and 63 women, ranging in age from 39 to 92 years (mean +/- SD = 70.9 +/- 10.1 years). Glare disability, examined by the Titmus Miller-Nadler Glare Tester, was found to be significantly correlated to types of intraocular lens, refractive power of intraocular lens, but not to age of patients or strength of postoperative astigmatism. The lower glare disability index value was found in patients implanted with posteriorly more curved biconvex or equiconvex surface, and within a range of 18.5-22 D compared with those implanted with convex anterior or convex-plano surface, and 22.5 D or more.

Adult↗
PubMed1995

Prevalence of antibodies against Borrelia species in patients with unclassified uveitis in regions in which Lyme disease is endemic and nonendemic.

We studied 93 patients with unclassified uveitis from two regions in Japan (Hokkaido and Kanagawa) to assess the contribution of Borrelia species to this condition. The seroprevalence of antibody to Borrelia species was higher in patients from Hokkaido than in those from Kanagawa. The unclassified uveitis of seropositive patients was probably a complication of Lyme borreliosis since (i) the antibody titers were as high as those in clinically diagnosed Lyme disease patients, (ii) healthy controls from Hokkaido showed low seroprevalence in contrast with unclassified uveitis patients from Hokkaido, and (iii) the reaction pattern of antibodies in sera from patients with unclassified uveitis was the same as that in patients with Lyme disease. This is the first report to reveal the high risk of Lyme borreliosis in patients with unclassified uveitis in regions endemic for Lyme disease. In case of unclassified uveitis as well as in cases of inflammatory disease of unknown origin, Lyme disease should be taken into consideration, especially in regions in which Lyme diseases is endemic, even if it is reported only in animals.

Animals↗
PubMed1995

HTLV-I associated uveitis in central Japan.

AIMS/BACKGROUND: Recently HTLV-I has been shown to cause a kind of endogenous uveitis in south west Japan, where HTLV-I infection is highly endemic. To investigate further the association of HTLV-I infection with the incidence of this uveitis, HTLV-I seroprevalence in central Japan, where HTLV-I infection is not endemic, was studied. METHODS: HTLV-I seroprevalence was investigated in 1579 patients with various ocular diseases and 1251 normal volunteers as a younger control group. Then HTLV-I seroprevalence was compared in each group. RESULTS: Of 1579 patients with various ocular diseases, 38 (2.41%) were seropositive. There was a statistically significant difference in HTLV-I seroprevalence between the undefined uveitis group and non-uveitic ocular diseases group (p < 0.05, Yates's correction). However, the seroprevalence in younger patients with undefined uveitis did not differ significantly from that in other groups. As regards the incidence of this type of uveitis, six of 12 (50%) seropositive patients, who were born in south west Japan and had lived in this area for 35 years, developed this undefined uveitis whereas only two of 26 (7.69%) seropositive patients in the other areas in Japan developed this uveitis. The difference was statistically significant (p < 0.05, Fisher's exact probability test). CONCLUSION: These results suggest that the incidence of this type of endogenous uveitis could be greatly influenced by environmental or hereditary factors including HLA.

Adolescent↗
PubMed1995

Clinical features of sarcoidosis in relation to HLA distribution and HLA-DRB3 genotyping by PCR-RFLP.

BACKGROUND: Susceptibility to the development of sarcoidosis has been demonstrated to be associated with HLA-DR5, -DR6, and -DR8 encoded by the DRB1 gene. However, involvement of the DRB3 (HLA-DR52) gene in the development of sarcoidosis remains unclear. METHODS: HLA-DRB3 genotyping was performed using the PCR-RFLP method and the clinical features of the patients with and without the DR3, 5, 6, 8 group antigens were compared. RESULTS: HLA-DRB3 genotyping indicated an association between DRB3*0101 and sarcoidosis. The DR8 haplotype lacking the DRB3 gene has been found to be increased significantly in sarcoidosis, suggesting that the HLA-DRB3 gene is not a primary determinant of predisposition to sarcoidosis. The association of DRB3*0101 with sarcoidosis is attributable to linkage disequilibrium with DR5- and DR6-associated alleles. There were significant decreases in the DR3, 5, 6, 8 group (DR5, DR6, or DR8) antigen frequencies in patients with retinal perivasculitis, high intraocular pressure (or secondary glaucoma), and optic nerve and/or macular lesion. Correlations were observed among the DR3, 5, 6, 8 group antigens, early onset sarcoidosis and disease with fewer intraocular lesions. CONCLUSION: This established a molecular basis for some of the clinical heterogeneity observed in sarcoidosis.

Adolescent↗
PubMed1995

Three-dimensional ultrastructure of human glomerular basement membrane by a quick-freezing and deep-etching method.

The three-dimensional ultrastructure of glomerular basement membrane (GBM) in surgically resected human kidneys was observed by the quick-freezing and deep-etching method. In three layers of human GBM, the middle layer exhibited polygonal meshwork structures, which were composed of fine fibrils. In addition, the outer and inner layers were formed by lines of perpendicular fibrils, which connected the epithelial or endothelial cell surfaces with the meshwork structures of the middle layer. These ultrastructures might correspond to the three layers, such as lamina densa and laminae rara externa and interna, which were also observed on conventional ultrathin sections. It is concluded that the human GBM has the same meshwork structures and perpendicular fibrils as those previously observed in animals and that these structures may act functionally as size and/or charge barriers.

Adult↗
PubMed1995

Ultrastructural study of basal lamina of retinal pigment epithelium.

The ultrastructure of basal lamina (BL) of retinal pigment epithelium (RPE) in guinea pigs was studied by the quick-freezing, deep-etching (QF-DE) method. The retinal tissue was quickly frozen, fractured and deeply etched. A replica was prepared by shadowing with platinum and carbon. Electron micrographs of the BL of RPE provide a three-dimensional (3-D) ultrastructure. The lamina lucida was filled with traversing filamentous structures, which connected the basal infolding of RPE with the lamina densa. The lamina densa consisted of a 3-D meshwork structure. It is suggested that the traversing filamentous structures in the lamina lucida might play a role in anchoring the basal infolding of RPE and in maintaining the normal architecture.

Animals↗
PubMed1995

Immunocytochemical study of dystrophin-related protein in the rat retina.

Dystrophin-related protein (DRP) has been reported to exist in the brain, but there are no reports describing its existence in the retina. In the present study, DRP localization was examined in rat retinas by immunohistochemistry in comparison to dystrophin localization. Rat retinas were fixed using paraformaldehyde and immunostained with one antidystrophin antibody and two anti-DPR antibodies. Dystrophin was observed in the outer plexiform layer, but DRP was recognized in ganglion cell layer and inner nuclear layer, but not in the outer plexiform layer. DRP has been thought to exist under the plasma membrane, but the present study clarified that DRP in the retina was localized throughout the perikaryon of the neuronal cells. These results suggest that DRP may play a distinct role from that of dystrophin in the rat retina.

Amino Acid Sequence↗
PubMed1995

Ultrastructural studies on the corneal superficial epithelium of rats by in vivo cryofixation with freeze substitution.

The method of in vivo cryofixation with freeze substitution (VC-FS) was used to examine the natural ultrastructure of the corneal superficial epithelium under the transmission electron microscope, and the results have been compared with the conventional method. With the VC-FS method, the ultrastructure down to 8 microns in depth was well preserved in the specimen. There was a layer of homogeneous material thought to be tear film on the corneal surface. Except for the intercellular spaces presenting under the first and sometimes also the second layers of the epithelial cells, other adjacent cells were in close contact without any spaces between them or between the desmosomes. In contrast, when using the conventional method, intercellular spaces were found between adjacent cells in all the layers of epithelium, and no tear film remained on the corneal surface. VC-FS is considered to be a better way to preserve the structure of tissue in its natural state than the conventional method and to be a useful method for the morphological study of the corneal epithelium and the tear film. Intercellular spaces, a kind of artifact, can be reduced by this method.

Animals↗
PubMed1995

Comparative study on topical and oral administration of ofloxacin for Pseudomonas corneal ulcer in rabbits.

Pseudomonas aeruginosa is one of the most frequently isolated microorganisms in bacterial corneal ulcers in Japan and other countries. We evaluated a topical application of 0.3% ofloxacin (OFLX) for Pseudomonas corneal ulcer in rabbits and compared it to the clinical effects of OFLX in topical and oral applications. All corneas in the control groups of both experiments showed total leukoma with a score of 4 on the seventh day. On the other hand, in the preventive experiment, all the scores in the OFLX-treated group were 0, and those in the therapeutic experiment were smaller than those of both the control and oral groups. The results indicate that topical OFLX is effective on Pseudomonas corneal ulcer in rabbits.

Administration, Oral↗
PubMed1995

[A case of p-ANCA positive necrotizing vasculitis associated with Graves' disease].

A 22-year-old female who had been suffering from Graves' disease developed p-ANCA positive necrotizing vasculitis. Her Graves' disease has been treated with propylthiouracil (PTI) for 6 years, which failed to improve serum TSH. She developed transient and recurrent polyarthralgia 4 years before. Because of microscopic hematuria and polyarthralgia, She visited our hospital last year. She had hypergammaglobulinemia and microhematuria at that time. But no autoantibody was noted except anti-microsomal antibody at that time. Skin biopsy from her finger subdermal nodule revealed necrotizing vasculitis of small vessels. Serum p-ANCA was positive. She was admitted under the diagnosis of p-ANCA positive necrotizing vasculitis. Renal biopsy revealed mesangium proliferative glomerulonephritis. Since she developed telescoped sediments after admission, predonisolone (PSL) 50 mg daily was started. Clinical and laboratory findings improved quite well. PSL was gradually tapered after 6 weeks. She is being maintained in good condition on tapering doses of both PSL and PTI. The coincidence of Graves' disease and vasculitis is rare. This case may provide some important immunological insights into the study of pathogenesis of necrotizing vasculitis and Graves' disease.

Adult↗
PubMed1995

Dystrophin localization at presynapse in rat retina revealed by immunoelectron microscopy.

PURPOSE: It has been accepted that retinal dystrophin is localized in the outer plexiform layer (OPL) of the retina, but no electron microscopic evidence has been reported until now. Using immunoelectron microscopy, the authors investigate whether retinal dystrophin localizes at the presynaptic or postsynaptic membrane of synaptic regions. METHODS: Monoclonal antibody raised against human dystrophin C-terminus was used. Immunoblotting analysis was used for testing dystrophin protein in retinal tissues. Tissue preparations were stained with the immunofluorescence or immunoperoxidase method and were observed with light and electron microscopy. RESULTS: Immunoblotting analysis showed a molecular weight of band 420 kDa in the sodium dodecyl sulfate--polyacrylamide gel electrophoresis of the retinal tissues. Immunoelectron microscopy disclosed that retinal dystrophin was localized at the presynaptic membrane of synaptic regions in the OPL. CONCLUSIONS: Rat retinal dystrophin localizes at the presynaptic membrane in the OPL, suggesting that it may play some role in the neurotransmitter release of the photoreceptor cell.

Amino Acid Sequence↗
PubMed1995

[DNA ploidy pattern and p53 overexpression in gastric cancer].

DNA ploidy pattern was determined by flow cytometry and p53 overexpression was investigated immunohistochemically in 145 primary gastric cancers. Aneuploid patterns were found in 78 (65%) and diploid patterns in 67 (46%). Metastasising to lymph nodes was observed more frequently in cases with aneuploid tumors, as compared to those with diploid tumors (p < 0.01). DNA ploidy patterns were related to overexpression of p53. The incidences of overexpression of p53 in aneuploid tumors and diploid ones were 65% and 33%, respectively (p < 0.05). Thus, we suggest that gastric carcinomas with the aneuploid pattern have mutation of tumor suppressor gene p53 and high potential to metastasize to lymph nodes.

Cell Cycle↗