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Biomedical subjects

S Ohno

Publications and source records attributed to S Ohno.

At least 685 records · Page 38Linked to original sources
PubMed1991

Ultrastructural studies of collagen fibers of the cornea and sclera by a quick-freezing and deep-etching method.

The ultrastructure of collagen fibers of the cornea and sclera of rabbits was studied by a newly developed quick-freezing and deep-etching method. An isopentane-propane mixture (-193 degrees C) cooled in liquid nitrogen was used for quick-freezing of the tissues. The frozen tissues were fractured in nitrogen, deeply etched and shadowed with platinum and carbon. Corneal collagen fibers were observed to be longitudinally arranged and separated by moderately wide interfibrillar spaces. Interconnecting filaments were three-dimensionally radiating between the collagen fibers, which were 40.6 +/- 5.0 nm in diameter and 42.0 +/- 2.8 nm in periodicity. In contrast, scleral collagen fibers were compactly organized, with few interconnecting filaments. Five kinds of striations were clearly observed on the collagen fibers, which were 217.3 +/- 50 nm in diameter and 67.5 +/- 1.4 nm in major periodicity. These striations could hardly be observed in the fractured scleral collagen fibers. The present study reveals the ultrastructural differences between corneal and scleral collagen fibers through the use of a quick-freezing and deep-etching method.

Animals↗
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

20 beta-hydroxysteroid dehydrogenase of neonatal pig testis: reverse catalytic (oxidation) reaction.

Neonatal pig testicular 20 beta-hydroxysteroid dehydrogenase (20 beta-HSD) catalyzed the oxidation of 20 beta-hydroxysteroids, 17 alpha,20 beta-dihydroxypregn-4-en-3-one and 20 beta-hydroxypregn-4-en-3-one in the presence of beta-nicotinamide adenine dinucleotide phosphate (beta-NADP+). The behavior of 20 beta-HSD activity toward the substrate of 17 alpha,20 beta-dihydroxypregn-4-en-3-one differed from the catalytic reaction for 20 beta-hydroxypregn-4-en-3-one. The enzyme could catalyze not only 20 beta-hydroxysteroids but also 20 alpha-hydroxy-5-ene steroids, 20 alpha-hydroxypregn-5-en-3 beta-ol and 17 alpha,20 alpha-hydroxypregn-5-en-3 beta-ol with 22.1 and 8.7% of activity relative to 20 beta-hydroxypregn-4-en-3-one, respectively. The enzyme preferentially required beta-NADP+, and also utilized beta-nicotinamide adenine dinucleotide beta-NAD+ and beta-nicotinamide adenine dinucleotide 3'-phosphate (beta-3'-NADP+) nonspecifically as the cofactor. The optimum pH was observed at pH 7.5 with the substrate of 20 beta-hydroxypregn-4-en-3-one. The activation energies obtained from oxidation-reduction reactions of 20 beta-HSD for the substrate of 20 beta-hydroxypregn-4-en-3-one, progesterone and 17 alpha-hydroxyprogesterone were estimated at 13.8, 27.0 and 20.0 kcal/mol, respectively.

Animals↗
PubMed1991

[Purification and some properties of 3 alpha-hydroxysteroid dehydrogenase from pig adrenal cytosol].

A 3 alpha-reducing activity of 5 alpha-dihydrotestosterone (5 alpha-DHT) was found in pig adrenal cytosol. The enzyme (3 alpha-hydroxysteroid dehydrogenase: 3 alpha-HSD) has been purified to homogeneity from pig adrenal cytosol by ammonium sulfate precipitation followed by DEAE-cellulose, 2', 5'-adenosine diphosphate-Sepharose and Sephadex G-100 column chromatographies. The molecular weight was estimated to be 33,000 and 39,000 by gel filtration and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Isoelectric point was estimated to be 8.5 by isoelectric focusing. The Km and Vmax values for 5 alpha-DHT in the reduction were 10.2 microM and 10.6 nmol/min/mg. The enzyme utilized reduced nicotinamide adenine dinucleotide phosphate (NADPH) or reduced nicotine amide adenine dinucleotide (NADH) in the reduction as a cofactor, but it preferentially required NADPH rather than NADH. Furthermore, the purified enzyme catalyzed not only 3 alpha-reduction of 5 alpha-DHT (9.65 nmol/min/mg), but also catalyzed 20 alpha-reduction of 17 alpha-hydroxyprogesterone (0.58 nmol/min/mg). The enzyme activity of 3 alpha-HSD was strongly inhibited by Hg2+, but it was not inhibited by medroxyprogesterone acetate and some anti-inflammatory agents. No remarkable differences was demonstrated between 3 alpha-HSD and 20 alpha-HSD activity under the influence of heat treatment, divalent cation, anti-inflammatory agents and some inhibitory steroids. These results strongly suggest that 3 alpha-HSD purified from pig adrenal cytosol is a bi-functional enzyme catalyzing 3 alpha- and 20 alpha-HSD activities.

20-Hydroxysteroid Dehydrogenases↗
PubMed1991

Transfection with protein kinase C alpha confers increased multidrug resistance to MCF-7 cells expressing P-glycoprotein.

Cross-resistance to anticancer drugs, termed multidrug resistance (mdr), has been functionally associated with the expression of a plasma membrane energy-dependent efflux pump, termed P-glycoprotein, the product of the mdr1 gene. When MCF-7 breast carcinoma cells were transfected with the human mdr1 gene (BC-19 cells), they expressed levels of P-glycoprotein equivalent to those of cells selected for resistance to doxorubicin (MCF-7/ADR) but exhibited 10- to 50-fold less resistance to doxorubicin and vinblastine. We have now demonstrated that when BC-19 cells were stably transfected with protein kinase C alpha (PKC alpha), resistance to doxorubicin and vinblastine was increased; wild-type MCF-7 cells transfected with PKC alpha did not exhibit any change in drug resistance. Increased resistance in PKC alpha-transfected BC-19 cells was associated with enhanced PKC activity and phosphorylation of P-glycoprotein and decreased drug accumulation. The PKC activator, phorbol dibutyrate, further increased resistance to doxorubicin and stimulated P-glycoprotein phosphorylation. These results demonstrate that transfection of P-glycoprotein-expressing cells with PKC resulted in increased mdr and that PKC may have served as an important modulator of this process.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
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↗
PubMed1991

Two cases of cicatricial pemphigoid showing atypical immunofluorescent findings.

We describe two patients with the clinical symptoms of cicatricial pemphigoid (CP). Biopsy specimens of the conjunctiva were taken. Histologic examination revealed subepidermal bullae and infiltration of inflammatory mononuclear cells. Direct immunofluorescent study showed immunoglobulins bound to the basement membrane zone (BMZ) in these patients. The patients also had intercellular immunoglobulin deposition in the conjunctival epithelium. No circulating anti-BMZ antibodies were detected, but one patient had a circulating antiintercellular antibody. Rare cases of CP with atypical immunofluorescent findings are reported.

Aged↗
PubMed1991

[Evaluation of two quantitative tests for salivary secretion--the chewing gum test and the Saxon test in normal subjects and in patients with Sjögren's syndrome].

A cooperative multicenter study was performed to evaluate two salivary secretion methods-the chewing gum test and the Saxon test by a crossover method. Twenty healthy volunteers and 27 patients with Sjögren's syndrome were examined. In healthy controls the amount of saliva collected per minute was larger in the Saxon test. Both tests revealed a significant decrease of salivary secretion in patients with Sjögren's syndrome, but the amount of saliva per minute was also larger in Saxon test. By repeated trials of both tests a notable increase of saliva was always observed at the second trial. Since this phenomenon may be due to the learning effect of the tests, one should perform at least one practice before starting formal tests. Saxon test could be performed in a patient having dental prostheses who was unable to masticate chewing gum. The Saxon test, thus, may be an efficient method, to evaluate the salivary secretory function.

Adult↗
PubMed1991

[A case of metastatic Enterococcus faecalis endophthalmitis].

We reported a case of successful treatment of early-stage metastatic endophthalmitis caused by Enterococcus faecalis with vitrectomy and lensectomy. The case was a 50-year-old male with poorly controlled diabetes. Following T-tube drainage for a necrotic cholecystitis operation, he developed iridocyclitis in both eyes as well as fever. At the time of his first visit to our clinic, his right eye had already lost light perception. His left eye had visual acuity recognizing of hand movement, marked uveitis, complicated cataract, and dense vitreous opacity. As gram positive cocci were isolated from the aspirated vitreous, we conducted lensectomy and vitrectomy under irrigation of antibiotics. With systemic postoperative antibiotics and human immunoglobulin, the patient showed remarkable improvement in his ocular fundus. By 60 days after the operation, the visual acuity of his left eye recovered to 4/20. Metastatic Enterococcus faecalis endophthalmitis has almost nerve been reported in Japan. The diagnosis and treatment of this disease with a reference to the above findings were discussed.

Endophthalmitis↗
PubMed1991

[Immunogenetic mechanism of Behçet's disease].

In order to investigate the immunogenetic mechanism of Behçet's disease, frequencies of HLA antigens were studied in patients. The subjects consisted of 66 patients and 99 normal controls. A lymphocyte cytotoxicity test was used for typing HLA-A, -B, -C, -DR, -DQ antigens. HLA-DP antigens were analyzed by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. A significant increase of HLA-B15 was observed in the patients. In contrast, no significant difference was observed in HLA-Bw52 which possesses only two different amino acids from HLA-B15. On the contrary, frequencies of HLA-A11, HLA-Aw33, HLA-B35, HLA-B44 and HLA-DQw1 were significantly lower in the patients than in the controls. No significant difference was observed in HLA-DP antigens. These results suggest that Behçet's disease involves both disease susceptibility factors and disease resistance factors and that such genetic factors are mapped within or very close to the HLA-B gene in the class I gene region. Additionally class II HLA-DQ antigen is associated with disease resistance factors.

Amino Acid Sequence↗
PubMed1991

Ultrastructural studies of hepatocyte cytoskeletons of phalloidin-treated rats by quick-freezing and deep-etching method.

We observed hepatocyte cytoskeletons in phalloidin-treated rats by the quick-freezing and deep-etching method in three dimensions and compared them with the ultrastructural findings on conventional ultrathin sections. The numbers of microvilli in dilated bile canaliculi were decreased in the rats treated with phalloidin for 1 wk. In hepatocytes the cytoplasm around bile canaliculi could be divided into three layers, increased microfilament layer, cell organelle layer of secretory system and increased smooth surface endoplasmic reticulum layer. In the rats treated with phalloidin for 4 wk, microfilaments were extended into the cytoplasm near the nucleus in addition to the increased number of large lysosomes and microtubules. In both groups, three-dimensional structures of microfilaments could be visualized around bile canaliculi and along cell borders by the quick-freezing and deep-etching method. The branching microfilaments with the diameters of 7 to 10 nm were directly attached to other filaments, cell organelles or cytoplasmic sides of cell membranes. Moreover, bundled intermediate filaments were increased around peribiliary microfilaments associated with long-term cholestasis. It is suggested that excessive accumulation of peribiliary microfilaments disturb the secretion of bile components into bile canaliculi. The cytoskeletal reorganizations of intermediate filaments seem to alter the arrangements of various cell organelles.

Actin Cytoskeleton↗
PubMed1991

[Abnormal vergence eye movement during eyelid closure caused by a pineal tumor].

A case with abnormal eye movement induced by eyelid closure and selective paralysis of downward gaze was reported. CT scan and MRI imaging revealed a pineal tumor with bilateral involvement of the thalamomesenchephalic junctions without obvious damage to the posterior commissure. Histopathologically, the tumor was a germinoma. The pupillary light reflex was absent and near reflex was reduced. Lightning eye movement, skew deviation and convergence-retraction nystagmus were observed. The horizontal eye movement was normal in both eyes. The eye did not move downward below the level of direct forward gaze spontaneously or on attempted downward gaze. Downward vestibulo-ocular reflex was absent. Bilateral abnormal vergence eye movement with alternating convergence and divergence was observed during eyelid closure. The cycle of the abnormal eye movement was about 3Hz and there was no fast phase. The abnormal eye movement was not observed in the darkened room with both eyes open. After subtotal removal and radiation therapy of the pineal tumor, the abnormal eye movement disappeared.

Adult↗
PubMed1991

[A case of Sjögren's syndrome with a clinical course similar to diffuse panbronchiolitis].

A 64-year-old man was admitted because of some infection of the airway. Chest roentgenography showed a bilateral reticulonodular shadow which was similar to the shadow of DPB. Pathological findings obtained by lung biopsy indicated bronchiolitis. This case was diagnosed as Sjögren's syndrome because of the increase of titers of anti-ssA and anti-ssB antibody, lachrymal dysfunction, pathological findings and sialography. The relationship between DPB and lung lesions of Sjögren's syndrome was investigated.

Bronchiolitis↗
PubMed1990

A phorbol ester receptor/protein kinase, nPKC eta, a new member of the protein kinase C family predominantly expressed in lung and skin.

Protein kinase C (PKC)-related cDNA clones isolated from mouse epidermis cDNA library encoded a 78-kDa protein, nPKC eta. nPKC eta contains a characteristic cysteine-rich repeat sequence (C1 region) and a protein kinase domain sequence (C3 region), both of which are conserved among PKC family members. However, nPKC eta lacks a putative Ca2+ binding region (C2 region) that is seen in conventional PKCs (alpha, beta I, beta II, gamma), but not in novel PKCs (nPKC delta, -epsilon, -zeta). nPKC eta shows the highest sequence similarity to nPKC epsilon (59.4% identity). The similarity extends to the NH2-terminal sequence (E region) which corresponds to one of the divergent regions (D1 region). Northern blot analysis showed that the mRNA for nPKC eta is highly expressed in the lung and skin but, in contrast to other members of the PKC family, only slightly expressed in the brain. nPKC eta expressed in COS cells shows phorbol ester binding activity with a similar affinity to nPKC epsilon. Antiserum raised against a COOH-terminal peptide of nPKC eta identified an 82-kDa protein in mouse lung extract as well as in an extract from COS cells transfected with the nPKC eta-cDNA expression plasmid. Autophosphorylation of nPKC eta immunoprecipitated with the specific antiserum was observed, indicating that nPKC eta is a protein kinase. These results clearly demonstrate the existence and the possible importance of nPKC eta as a member of the phorbol ester receptor/protein kinase, PKC, family.

Amino Acid Sequence↗
PubMed1990

Possible role of Ca2(+)-independent protein kinase C isozyme, nPKC epsilon, in thyrotropin-releasing hormone-stimulated signal transduction: differential down-regulation of nPKC epsilon in GH4C1 cells.

Protein kinase C (PKC) molecular species of GH4C1 cells were analyzed after separation by hydroxyapatite column chromatography. A novel Ca2(+)-independent PKC, nPKC epsilon, was identified together with two conventional Ca2(+)-dependent PKCs, PKC alpha and beta II by analysis of kinase and phorbol ester-binding activities, immunoblotting using isozyme-specific antibodies, and Northern blotting. These PKCs are down-regulated differently when cells are stimulated by outer stimuli; phorbol esters deplete PKC beta II and nPKC epsilon from the cells more rapidly than PKC alpha, whereas thyrotropin-releasing hormone (TRH) at 200 nM depletes nPKC epsilon exclusively with a time course similar to that induced by phorbol esters. However, translocation of PKC alpha and beta II to the membranes is elicited by both TRH and phorbol esters. These results suggest that TRH and phorbol ester activate PKC alpha and beta II differently but that nPKC epsilon is stimulated similarly by both stimuli. Thus, in GH4C1 cells, Ca2(+)-independent nPKC epsilon may play a crucial role distinct from that mediated by Ca2(+)-dependent PKC alpha and beta II in a cellular response elicited by both TRH and phorbol esters.

Animals↗
PubMed1990

Immunohistochemical evaluation of squamous cell carcinoma antigen and S-100 protein-positive cells in human malignant esophageal tissues.

Localization and intensity of squamous cell carcinoma-related antigen (SCC-Ag) and infiltration of Langerhans' cells (LC) were investigated immunohistochemically, using anti-SCC-Ag and anti-S-100 protein antisera, respectively, in 36 cases of squamous cell carcinoma of the human esophagus. The SCC-Ag was an indicator of histologic differentiation of squamous cell carcinoma but not of malignant potential. The population density of LC correlated well with the histologic stage, vessel invasion, and postoperative survival time. In patients with a marked infiltration of LC, survival time was longer than for those in whom the infiltration was slight (P less than 0.05). The density of the LC can serve an indicator of defense of the host against the carcinoma. There was no correlation between SCC-Ag and S-100 protein-positive cells.

Adult↗