Biomedical subjects

S Ohno

Publications and source records attributed to S Ohno.

At least 289 records · Page 16Linked to original sources

PubMed1998

Poorly differentiated desmin-negative and vimentin-positive leiomyosarcoma of the stomach examined by the immunohistochemical and quick-freezing and deep-etching methods.

A poorly differentiated leiomyosarcoma of the stomach in a 41-year-old woman is reported. The diagnosis was confirmed by the diffuse immunohistochemical reaction to HHF35, and the presence of focal density and caveolas in some of the tumour cells by conventional electron microscopy. Immunohistochemically, most tumour cells had an undifferentiated nature, in which negative immunostaining for desmin, alpha-smooth muscle actin, and type IV collagen, and positive immunostaining for vimentin were observed. By the quick-freezing and deep-etching (QF-DE) method, these tumour cells revealed the loss of bundled actin and myosin filaments, which constitute desmin associated structures (focal densities and dense patchy areas). Their cytoplasm had many mitochondria and other cell organelles. The intermediate filaments (IFs), which were determined to be vimentin by immunohistochemistry, were observed in the inter-organellar spaces, and connected with these cell organelles. Actin filaments formed a meshwork structure and were distributed mainly in subplasmalemmal regions. Although a basal lamina was not detected by conventional electron microscopy, basal lamina-like structures, an association between the extracellular matrices and the cell membrane, were observed. Using the QF-DE method, three dimensional ultrastructural alterations of the cytoskeleton and extracellular matrix of the leiomyosarcoma were observed.

Actins↗

PubMed1998

Laparoscopic repair of a perforated duodenal ulcer in two patients.

The laparoscopic repair of a perforated duodenal ulcer was effectively done in two patients both of whom were poor risks for surgery. One was a 39-year-old woman with a history of bronchial asthma since she was 20 years of age, while the other was a 76-year-old man with hepatocellular carcinoma, lung cancer, and diabetes mellitus. The postoperative course of these patients was uneventful. Based on these findings, the laparoscopic repair of a perforated duodenal ulcer should thus be considered as a first choice of treatment for a perforated duodenal ulcer, even in poor-risk patients.

Adult↗

PubMed1998

Association between MICA gene A4 allele and acute anterior uveitis in white patients with and without HLA-B27.

PURPOSE: Acute anterior uveitis is strongly associated with the HLA-B27 antigen and triggered by the involvement of some external factors. However, it is uncertain whether HLA-B27 itself or other gene(s) near the HLA-B region in a linkage disequilibrium with HLA-B27 predispose to this uveitis. We therefore investigated microsatellite polymorphism in the transmembrane region of the major histocompatibility complex class I chain-related gene A (MICA), located 47 kilobases (kb) on the centromeric side of the HLA-B gene on the short arm of chromosome 6 within 6p21.3. METHODS: We examined the following patients for MICA gene polymorphism by means of polymerase chain reaction and subsequent automated fragment detection by fluorescent-based technology: 64 (37 HLA-B27-positive and 27 HLA-B27-negative) whites with acute anterior uveitis, 74 (67 HLA-B27-negative and 7 HLA-B27-positive) ethnically matched random controls, and 36 HLA-B27-positive healthy controls. RESULTS: The microsatellite allele consisting of four repetitions of GCT/AGC (designated A4 allele) was present at the significantly higher phenotype frequency (71.9%) in the patient group than in the ethnically matched random control group (13.5%) (P < .0000001, corrected P < .0000001). The A4 allele was strongly linked to HLA-B27 in a white population. However, the A4 allele was also found at the significantly higher phenotype frequency (37.0%) even in the HLA-B27-negative patient group than in the ethnically matched HLA-B27-negative control group (4.5%) (P = .0086, corrected P = .043). CONCLUSIONS: These results suggest that the MICA gene itself or other nearby gene(s) linked to the MICA A4 allele may be involved in the development of acute anterior uveitis in a white population.

Acute Disease↗

PubMed1998

Early experience of endoscopic extirpation of benign breast tumors via an extra-mammary incision.

The early results of 6 patients with a benign breast mass who underwent an endoscopic extirpation via an extra-mammary incision were presented. Under general anesthesia in either a lateral or supine position, a 12-mm and two 5-mm incisions in the infra-mammary line in 2 patients and in the mid-axillary line in the remaining 4 patients were made. The tumors were then endoscopically extirpated. Preoperative aspiration needle cytology revealed six fibroadenomas in 5 patients and one intraductal papilloma in the other patient. All patients were single females with a mean age of 22.5 years. The maximal size of the masses was 5 cm on average. The average operation time was 3 hours 20 minutes. Regarding postoperative complications, subcutaneous emphysema extending to the neck due to CO2 gas inflation and a burn in the skin were seen in 1 patient each; however, no further treatment was required in these cases. The postoperative hospital stay was 1.7 days on average, and all patients were extremely satisfied with the cosmetic results of the procedure. The cosmetic results are drastically improved by the application of endoscopic removal via extra-mammary approaches, which are newly introduced, for benign breast tumors.

Adolescent↗

PubMed1998

Microsatellite polymorphism within the MICB gene among Japanese patients with Behçet's disease.

Behçet's disease (BD) is known to be associated with HLA-B51. In order to investigate the influence of the MICB gene, located about 120 kb centromeric of the HLA-B gene, on the susceptibility to BD, (CA/TG) dinucleotide repeat microsatellite polymorphism in intron 1 of the MICB gene was investigated among 77 Japanese patients with BD, 60 randomly selected controls and 28 HLA-B51-positive unrelated healthy controls. There was no significant difference in the phenotype frequency of the microsatellite polymorphism between the BD patients and controls. This result suggests that the MICB gene itself is not responsible for the development of BD, and that the candidate gene(s) for BD is located between the MICA and HLA-C genes.

Behcet Syndrome↗

PubMed1998

Developmental regulation of myotonic dystrophy protein kinase in human muscle cells in vitro.

From our previous studies, myotonic dystrophy protein kinase: gene product of myotonic dystrophy is localized at the terminal cisternae of sarcoplasmic reticulum of human adult muscle. Now we have studied the developmental expression of myotonic dystrophy protein kinase in aneurally cultured human muscles and contracting cross-striated muscles innervated with fetal rat spinal cord using a semi-quantitative reverse transcription-polymerase chain reaction method for myotonic dystrophy protein kinase messenger RNA expression, Western blot analysis, immunohistochemical examinations by laser scanning confocal microscopy and immunoelectron microscopy. About 65,000 mol. wt myotonic dystrophy protein kinase was detected in aneurally cultured muscles. Myotonic dystrophy protein kinase messenger RNA was expressed in both aneurally and innervated cultured muscles, but in early innervated cultured muscles the message was transiently lower than in aneurally cultured muscles and innervated cultured muscles in long-term co-culture. In aneurally cultured muscles, immature aneurally cultured muscles show a diffuse and irregular distribution of myotonic dystrophy protein kinase in the deeper cytoplasm near the nuclei. Ultrastructurally the immuno-products against myotonic dystrophy protein kinase were observed as dense deposits in parts of the membranes near the mitochondria. In innervated cultured muscles, immunofluorescent microscopy showed myotonic dystrophy protein kinase to be localized regularly in the I bands and A-I junctions. Ultrastructurally myotonic dystrophy protein kinase was localized in branched duct-like membranes in the early stage of innervated cultured muscles and then in small sacs at the I bands and A-I junctions of the sarcolemma in the mature stage. Our present studies strongly suggest that innervation plays an important role in the localization of myotonic dystrophy protein kinase in human skeletal muscle during development. We conclude that the expression of myotonic dystrophy protein kinase during development is under neuronal influence.

Animals↗

PubMed1998

Effect of intracameral anesthesia on the corneal endothelium.

PURPOSE: To evaluate the effects of intracameral anesthesia on the corneal endothelium. SETTING: Department of Ophthalmology, Yokohama City University School of Medicine, Yokohama, Japan. METHODS: This study comprised 24 eyes of 12 white rabbits. One eye of 3 rabbits each was injected with preservative-free lidocaine at concentrations of 0.02, 0.2, or 2% and the fellow eye injected with balanced salt solution (BSS) as a control. The anesthetic agent was injected into the anterior chamber using a bimanual technique. Immediately after enucleation, the cornea was examined by scanning electron microscopy. RESULTS: Scanning electron microscopy revealed no abnormal findings in the eyes injected with lidocaine 0.02 or 0.2% when compared with eyes in the control group. Scanning electron microscopy of the eyes injected with lidocaine 2% showed irregular hexagonal endothelial cells and a significant loss of microvilli. CONCLUSION: Intracameral anesthesia with high concentrations of lidocaine risks corneal endothelial damage but at the low concentration usually used in cataract surgery did not appear to have an adverse effect.

Anesthesia, Local↗

PubMed1998

Immunolocalization of myotonic dystrophy protein kinase in corbular and junctional sarcoplasmic reticulum of human cardiac muscle.

The subcellular localization of myotonic dystrophy protein kinase has been examined in human cardiac muscles with confocal laser-scanning microscopy and electron microscopy. A polyclonal antibody was produced against the synthesized peptide from a human kinase cDNA clone. We checked the antibody specificity for cardiac myotonic dystrophy protein kinase using an immunoblotting technique. Immunoblotting of extract from human cardiac muscles showed mainly 70 kDa and 55 kDa molecular weight bands. Confocal images of the protein kinase immunostaining showed striated banding patterns similar to those of skeletal muscles. In addition, the kinase was strongly detected around the intercalated disc. Immunoelectron microscopy showed that the kinase was mainly expressed in both corbular and junctional sarcoplasmic reticulum, but not in network sarcoplasmic reticulum. These results suggest that myotonic dystrophy protein kinase may be involved in the modulation of Ca2+ homeostasis in cardiac myofibres.

Blotting, Western↗

PubMed1998

The ultrastructure of anionic sites in rat articular cartilage as revealed by different preparation methods and polyethyleneimine staining.

The ultrastructure of anionic sites in the middle layer of rat articular cartilages was studied by two methods, the quick-freezing and deep-etching method, and the quick-freezing and freeze-substitution method. The anionic sites were visualized with a cationic tracer, polyethyleneimine. They were also compared with those revealed in tissues subjected to conventional fixation, such as pre-embedding or post-embedding. With the deep-etching method, three-dimensional meshwork structures were observed more clearly in the extracellular matrix compared with those seen in conventional ultrathin sections. In combination with polyethyleneimine staining, in which no chemical contrast was needed for visualization of anionic sites, numerous stained particles were detected around filaments in the extracellular matrix, indicating that they were anionic sites consisting mainly of proteoglycans. With the pre-embedding method and polyethyleneimine staining, the shapes of aggregated stained particles varied with different preparation procedures, including chemical fixation and contrasting. The fine meshworks were also observed with the post-embedding method and polyethyleneimine staining. It is suggested that such images of anionic sites, as revealed by the deep-etching method and the post-embedding polyethyleneimine-staining method with low-temperature dehydration, are probably closer to native states than those revealed by the conventional pre-embedding polyethyleneimine-staining method.

Animals↗

PubMed1998

Identification of a peptide inducing experimental autoimmune uveoretinitis (EAU) in H-2Ak-carrying mice.

When certain strains of mice bearing H-2Ak are immunized with the interphotoreceptor retinoid-binding protein (IRBP), EAU is induced. Thus far uveitogenic determinant(s) has not been determined in the H-2Ak mouse system. In addition it is hard to prepare purified IRBP. In the present study, to circumvent these problems we attempted to identify uveitogenic peptides derived from bovine IRBP in H-2Ak haplotype mice. Six peptides which had been selected according to the H-2Ak binding motif (Dxxxxxxxx[A, R, T]) were synthesized. We report here that all the peptides are immunogenic but only one peptide, K2, which consisted of IRBP201-216 residues, induces EAU in various mice carrying H-2Ak. Amino acid substitution of K2 revealed that the core region interacted with both H-2Ak and T cell antigen receptor (TCR). The amino acid sequence of the core region derived from bovine IRBP was identical to the corresponding region of mouse IRBP. In addition, K2 appeared to be a natural peptide antigen processed from bovine IRBP. Altogether, we concluded that K2 is one of the natural autoantigens involved in induction of EAU in H-2Ak mice.

Amino Acid Sequence↗

PubMed1998

Scanning electron microscopic study of the renal glomerulus by an in vivo cryotechnique combined with freeze-substitution.

The 3-dimensional ultrastructure of mouse renal glomeruli under normal haemodynamic conditions was studied by scanning electron microscopy using an in vivo cryotechnique followed by freeze-substitution, and compared with glomeruli prepared by conventional fixation methods. Mouse kidneys were frozen with a cryoknife apparatus and a liquid isopentane-propane mixture (-193 degrees C). Surface areas of the frozen tissues were freeze-fractured with a scalpel in liquid nitrogen. The specimens were routinely freeze-substituted, freeze-dried, ion-sputtered, and then observed in a scanning electron microscope at an accelerating voltage of 5 kV. Renal glomeruli showed good ultrastructural preservation of the surface tissues. Podocytes with interdigitating foot processes covering capillary loops exhibited smooth surface contours and their cell surfaces were arranged more tightly than those seen by the conventional fixation method. Filtration slits between foot processes were found to be narrow. The internal structure of the glomerular tuft was seen in the freeze-fracture faces. The capillary lumen with variously shaped erythrocytes was kept open in frozen glomeruli under normal blood circulation conditions. The ultrastructure of renal glomeruli, as revealed by the in vivo cryotechnique with freeze-substitution, appears to be closer to that of the living state.

Animals↗

PubMed1998

Morphological study by an 'in vivo cryotechnique' of the shape of erythrocytes circulating in large blood vessels.

Changes in the shape of erythrocytes circulating in large blood vessels of mice were examined by our 'in vivo cryotechnique'. The abdominal aorta and inferior vena cava (IVC) were cut vertically with a precooled knife and simultaneously an isopentane-propane mixture (-193 degrees C) was poured over them for freezing. They were freeze-substituted in acetone containing 2% osmium tetroxide. Some specimens were embedded in Quetol-812, and thick or ultrathin sections were examined by light or transmission electron microscopy. Serial ultrathin sections were used to reconstruct 3-dimensional images of native erythrocytes. Others were transferred into t-butyl alcohol and freeze-dried for scanning electron microscopy. The tissue surfaces were sufficiently frozen to prevent large ice crystal formation, and erythrocyte shapes were also preserved. The shapes of circulating erythrocytes appeared to be varied in the abdominal aorta but typical biconcave discoid shapes were rarely observed. Conversely, erythrocytes were approximately biconcave discoid in shape in the IVC. Our in vivo cryotechnique was useful for clarifying the in vivo morphology of erythrocytes circulating in large blood vessels.

Animals↗

PubMed1998

Phosphatidic acid-dependent phosphorylation of a 29-kDa protein by protein kinase Calpha in bovine brain cytosol.

Activation of phospholipase D (PLD) is involved in receptor-mediated signal transduction responses. Signaling from PLD to a downstream molecule(s) appears to be mediated by the PLD product phosphatidic acid (PA). A target molecule(s) of PA, however, has not yet been identified. The present study sought to define such a target molecule(s) of PA. In bovine brain cytosol, proteins with apparent molecular weights of 29,000 (p29) and 32,000 (p32) were prominently phosphorylated in the presence of PA, but not in its absence, indicating that there is a PA-regulated protein kinase (PARK) in bovine brain that phosphorylates p29 and p32. One of these substrates, p29, was purified to near homogeneity. Its partial amino acid sequence was determined and found to be identical to that of a known brain-specific 25-kDa protein (p25). The purified p29 was also readily recognized by and immunoprecipitated with an anti-p25 antibody. These results suggest that p29 is very similar to or identical with p25. Using the purified p29 as a substrate, PARK was purified to near homogeneity. The purified PARK had an apparent molecular weight of 80,000, was strongly recognized by an antiprotein kinase C (PKC)alpha antibody, and was activated by phosphatidylserine (PS) as well as PA. The PA- and PS-stimulated PARK activity was extremely augmented by the presence of 1 microM free Ca2+. In the presence of 1 mM EGTA, phorbol 12-myristate 13-acetate activated PARK synergistically with PA or PS. Similar results were obtained with the purified recombinant PKCalpha. From these results, it is suggested that the PARK activity purified might be attributed to PKCalpha. In p25-depleted bovine brain cytosol, which was prepared by treatment of bovine brain cytosol with the anti-p25 antibody, PA-dependent phosphorylation of p29, but not p32, was almost completely eliminated. When PKCalpha in bovine brain cytosol was depleted by its precipitation with the anti-PKCalpha antibody, neither p29 nor p32 in this PKCalpha-depleted cytosol was phosphorylated in the presence of PA. These results indicate that in bovine brain cytosol PA activates PKCalpha, which, in turn, phosphorylates p29, which may be identical with p25.

Animals↗

PubMed1998

Proliferative response of CD8+ gamma delta+ T cells to Streptococcus sanguis in patients with Behçet's disease.

To analyze the pathogenesis of Behçet's disease (BD), we investigated the immune response of peripheral blood T cell subsets from patients with BD to Streptococcus sanguis (S. sanguis) strain KTH-I, a bacteria suggested to be associated with the etiology of BD. Cultured peripheral blood mononuclear cells (PBMC) of patients with BD activated by lyophilized whole bacterium of S. sanguis were assayed by two-color flow cytometry using monoclonal antibodies (mAbs) specific for gamma delta+ T cell receptor, CD4 or CD8 molecules. The lymphostimulatory activity of S. sanguis to either gamma delta+ CD4-CD8-, gamma delta+ CD4-CD8+, gamma delta-CD4+CD8-, or gamma delta-CD4-CD8+ T cells was evaluated. The absolute number of gamma delta+ T cells from patients with BD (n = 8) as well as from healthy controls (n = 7) significantly increased after stimulation with S. sanguis, whereas gamma delta- T cells from both groups showed no response to S. sanguis. The absolute number of gamma delta+ CD8+ T cells from patients with BD significantly increased after stimulation with S. sanguis compared with healthy controls (p < 0.05). Peripheral gamma delta+ CD8+ T cells from patients with BD showed a significantly higher proliferative response to S. sanguis compared with healthy controls.

Adult↗

PubMed1998

Scanning electron microscopic study of flowing erythrocytes in hepatic sinusoids as revealed by 'in vivo cryotechnique'.

The purpose of this study is to develop a method for stabilizing erythrocytes under flowing condition in living livers, as revealed by scanning electron microscopy (SEM). After the procedure of the 'in vivo cryotechnique', both freeze-substitution and subsequent t-butyl alcohol freeze-drying methods were used for preparing SEM specimens. By freeze-fracturing with a scalpel in liquid nitrogen before the freeze-substitution, better preserved surface tissues were obtained for examination. Erythrocytes in hepatic sinusoids were clearly detected without plasma components by the freeze-substitution method, and well preserved in parts where they were flowing with their original shapes. Some were accumulated in sinusoids, especially injunctioning areas of sinusoidal networks, as compared with those in narrow lumens between hepatocyte plates. Shapes of such erythrocytes were various, locating along endothelial cells. After stopping the blood supply into livers by artificial cardiac arrest, their shapes were dramatically changed into biconcaves and they became aggregated side by side to be packed in the sinusoids. The three-dimensional shapes of flowing erythrocytes in hepatic sinusoids were demonstrated for the first time by the 'in vivo cryotechnique' combined with SEM.

Animals↗

PubMed1998

Scanning electron microscopic study of erythrocyte shapes artificially jetted through tubes at different pressures by 'in vitro cryotechnique for erythrocytes'.

A new cryotechnique for examining morphological changes of human erythrocytes at different jet pressures was developed in the present study. Human fresh or stored erythrocytes passing through a tube were jetted into precooled isopentane-propane mixture (-193 degrees C), which was named as 'in vitro cryotechnique for erythrocytes'. After the cryotechnique procedure, the routine freeze-substitution method and subsequent t-butyl alcohol freeze-drying method were used for preparing the scanning electron microscopic specimens. At 100 mmHg or higher pressures of jetting, lamellar-arranged erythrocytes were observed to have elongated shapes. The more the jetting pressure increased, the fewer discoid shapes of erythrocytes were observed. This cryofixation technique could preserve the morphology of erythrocytes jetting from tubes, and provide the three-dimensional image of erythrocyte surfaces, as followed by scanning electron microscopy.

Erythrocyte Deformability↗

PubMed1998

Major histocompatibility complex class II alleles in an Uygur population in the Silk Route of Northwest China.

HLA class II (DRB1, DQA1, DQB1 and DPB1) genotyping was performed in 57 unrelated Uygur individuals inhabiting the northwestern China area by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Among 98 DRB1 alleles tested, 23 alleles were detected, and DRB1*0701 (16.7%) and DRB1*0301 (14.0%) were the most and the second most common alleles, respectively. In 8 DQA1 alleles detected, DQA1*05 (26.3%), DQA1*03 (21.9%) and DQA1*0201 (21.1%) were very frequent. Of 21 DQB1 alleles tested, 13 were observed. Among them, DQB1*02 was highly predominant with the gene frequency of 32.5%. Of 46 DPB1 alleles tested, 15 were detected, among which DPB1*0401 (31.6%) was the most frequent. Two haplotypes predominate clearly; DRB1*0701-DQA1*0201-DQB1*02 (15.5%) and DRB1*0301-DQA1*05-DQB1*02 (12.6%). The dendrogram constructed by the neighbour-joining (NJ) method based on the allele frequencies of the DRB1, DQA1, DQB1 and DPB1 genes of 13 representative populations all over the world suggested that Uygur belonged to the Asian group and lay at the closest genetic distance to a Kazak population inhabiting the same area.

Alleles↗

PubMed1998

Case report: a patient who developed an amoebic liver abscess during treatment with interferon.

A 65-year-old female received recombinant interferon (IFN) alpha-2b daily for the treatment of chronic hepatitis C. Fever (39 degrees C or higher) developed 14 days after the start of administration. Abdominal computed tomography suggested multiple liver abscesses, which had not been detected before IFN administration. An autopsy revealed an amoebic liver abscess. A subclinical infection of Entamoeba histolytica in this case developed into amoebic liver abscess during IFN administration.

Aged↗