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S Ohno

Publications and source records attributed to S Ohno.

At least 217 records · Page 12Linked to original sources
PubMed1999

Interaction of the small G protein RhoA with the C terminus of human phospholipase D1.

Mammalian phosphatidylcholine-specific phospholipase D1 (PLD1) is a signal transduction-activated enzyme thought to function in multiple cell biological settings including the regulation of membrane vesicular trafficking. PLD1 is activated by the small G proteins, ADP-ribosylation factor (ARF) and RhoA, and by protein kinase C-alpha (PKC-alpha). This stimulation has been proposed to involve direct interaction and to take place at a distinct site in PLD1 for each activator. In the present study, we employed the yeast two-hybrid system to attempt to identify these sites. Successful interaction of ARF and PKC-alpha with PLD1 was not achieved, but a C-terminal fragment of human PLD1 (denoted "D4") interacted with the active mutant of RhoA, RhoAVal-14. Deletion of the CAAX box from RhoAVal-14 decreased the strength of the interaction, suggesting that lipid modification of RhoA is important for efficient binding to PLD1. The specificity of the interaction was validated by showing that the PLD1 D4 fragment interacts with glutathione S-transferase-RhoA in vitro in a GTP-dependent manner and that it associates with RhoAVal-14 in COS-7 cells, whereas the N-terminal two-thirds of PLD1 does not. Finally, we show that recombinant D4 peptide inhibits RhoA-stimulated PLD1 activation but not ARF- or PKC-alpha-stimulated PLD1 activation. These results conclusively demonstrate that the C-terminal region of PLD1 contains the RhoA-binding site and suggest that the ARF and PKC interactions occur elsewhere in the protein.

Binding Sites↗
PubMed1999

Decreased expression of myotonic dystrophy protein kinase and disorganization of sarcoplasmic reticulum in skeletal muscle of myotonic dystrophy.

Pathological expression of myotonic'dystrophy protein kinase (DMPK) in skeletal muscle of myotonic dystrophy (DM) was studied by Western blot analysis, immunohistochemistry, and immunoelectron microscopy of DMPK. Western blot analysis showed that DMPK protein in DM skeletal muscles dramatically decreased. DMPK-positive muscle fibers showed typical DM pathological changes such as type I atrophy, central nuclei, nuclear chains, and sarcoplasmic masses. In degenerated DMPK-positive muscle fibers, cross-striated bands disappeared, and irregular granular DMPK-positive materials appeared in sarcoplasm. By immunoelectron microscopy, DMPK was localized in the terminal cisternae of the sarcoplasmic reticulum (SR) in DM muscle. Swollen DMPK-positive SRs were detected between well preserved myofibrils in the early stage of DM muscle degeneration, and degenerated intramembranous structures with DMPK and an accumulation of mitochondria were observed between disorganized myofibrils in degenerated DM muscle. We concluded that SR is the primary site of the degeneration of DM skeletal muscle and that the decreased DMPK might cause dysregulation of intracellular calcium metabolism, which is followed by DM muscle degeneration.

Adenosine Triphosphatases↗
PubMed1999

Keio Mutation Database for eye disease genes (KMeyeDB).

A database of mutations in human eye disease genes has been constructed. This KMeyeDB employs a database software MutationView which provides graphical data presentation and analysis as a smooth user-interface. Currently, the KMeyeDB contains mutation data of 16 different genes for 18 eye diseases. The KMeyeDB is accessible through http://mutview.dmb.med.keio.ac.jp with advanced internet browsers.

Age of Onset↗
PubMed1999

Four new genotypes of adenovirus type 3 isolated from patients with conjunctivitis in Japan.

Adenovirus type 3 (Ad3) was the most frequently isolated serotype from patients with conjunctivitis during the period from 1989 to 1991 in Japan. All Ad3 strains isolated in 1990 had an identical genotype, Ad3f. However, in 1992, the predominant serotype was replaced by Ad4. The genome type was examined to determine whether genetic changes existed in Ad3 isolates in 1992. Ad3 isolated from 55 patients with acute conjunctivitis during the period from June 1992 to February 1993 in Japan was assessed by genome typing with restriction endonucleases BamH I, Bgl II, Hind III, and Sma I recognizing 6-base-pair sequences. The emergence of four new genotypes of Ad3 was identified; one with a new Bam HI site (one isolate), one with a new Bgl II site (two isolates), one with a new Hind III site (three isolates) and one with a new Sma I site (two isolates). This study demonstrates that the emergence of a new genotype of Ad3 may contribute to the replacement of the predominant serotype associated with adenovirus conjunctivitis in Japan.

Adenovirus Infections, Human↗
PubMed1999

Prognostic factors after extended esophagectomy for squamous cell carcinoma of the thoracic esophagus.

BACKGROUNDS AND OBJECTIVES: In Japan, extended esophagectomy with extensive lymphadenectomy has become the standard surgical procedure for carcinoma of the thoracic esophagus. Although mortality and morbidity rates after such extensive esophagectomy have been acceptable, the long-term outcomes are not necessarily satisfactory. METHODS: Among 235 patients with primary squamous cell carcinoma of the thoracic esophagus between June 1981 and March 1998, 143 patients (60.9%) underwent extended esophagectomy with extensive lymphadenectomy. To exclude the effects of surgery-related postoperative complications, 14 patients who died within 90 days after operation were excluded. Thus, clinicopathological characteristics and prognostic factors of 129 patients were retrospectively investigated. RESULTS: Sixty-three patients were alive and free of cancer. Sixty-six patients died: 37 of recurrence of the esophageal cancer and 29 of other causes. The 1-, 3-, 5-, and 10-year overall survival rates in the 129 patients were 78.8%, 53.5%, 45.8%, and 30.9%, respectively, and the disease-specific survival rates were 85.7%, 69.1%, 67.9%, and 56.2%, respectively. The factors influencing the disease-specific survival rate were tumor location (upper third vs. non-upper third), Borrmann classification (0, 1 vs. 2, 3), size of tumor (</=3.0 vs. >3.0 cm), depth of invasion (T1, 2 vs. T3, 4), number of lymph node metastases (0 or 1 vs. >/=2), time of operation (</=420 vs. >420 min), amount of blood transfused (</=2 vs. >/=3 U), lymph vessel invasion (marked vs. not marked), and blood vessel invasion (marked vs. not marked). Among those significant variables, independent prognostic factors for survival determined by multivariate analysis were number of lymph node metastases (P < 0.001), amount of blood transfusions (P = 0.0016), and tumor location (P = 0.0382). CONCLUSIONS: Patients with a single metastatic node after extended esophagectomy should be considered to have excellent prognosis, like patients with pN0 tumors. Patients with multiple involved nodes should receive aggressive postoperative adjuvant treatments. Reduced blood loss during extended esophagectomy and minimal blood transfusions might improve the outcome of curative esophageal resections.

Aged↗
PubMed1999

Association analysis between the MIC-A and HLA-B alleles in Japanese patients with Behçet's disease.

OBJECTIVE: Behçet's disease is known to be strongly associated with HLA-B51 in many different ethnic groups. Recently, by association analysis using refined microsatellite mapping, the critical region for Behçet's disease was identified as a 46-kb segment centromeric to the HLA-B gene. No expressed gene has been detected in this segment to date except the MIC-A (major histocompatibility complex class I chain-related gene A) and HLA-B genes. The present study was undertaken to analyze allelic distribution of the MIC-A gene among Japanese patients with Behçet's disease. METHODS: Ninety-five Japanese patients with Behçet's disease and 116 ethnically matched healthy controls were enrolled in this study. MIC-A genotyping was performed by direct sequencing of polymerase chain reaction products from exons 2, 3, and 4 of the MIC-A gene, using an automated DNA sequencer. RESULTS: The MIC-A009 allele was significantly more frequent in the patient group (69.5%) compared with the healthy controls (31.0%) (relative risk 5.06, corrected P = 0.00000024). In stratification analysis on the confounding effect of MIC-A009 on HLA-B*51 association and vice versa, Behçet's disease was distinctively associated only with HLA-B*51. Further, MIC-A009 was found to be strongly associated not only with HLA-B51, but also with HLA-B52, which was not increased in the patient group to any degree. CONCLUSION: These results imply that the real disease susceptibility gene involved in the development of Behçet's disease is the HLA-B*51 allele itself and that the significant increase of the MIC-A009 allele in the patient group results secondarily from a strong linkage disequilibrium with HLA-B*51.

Adult↗
PubMed1999

Gene duplication and the uniqueness of vertebrate genomes circa 1970-1999.

In this article I review research undertaken over the past 30 years into the role that gene duplication played in shaping vertebrate genomes. I discuss early karyotype studies that pointed to a relative stability of mammalian and avian genomes, the discovery and possible evolutionary significance of enormous genomes in urodele amphibians and lungfish, genome compaction in certain specialised bony fish, evidence for two rounds of total genome doubling in early vertebrate evolution and the fate of duplicated genes in polyploid fish.

Amphibians↗
PubMed1999

The one-to-four rule and paralogues of sex-determining genes.

Because of two successive rounds of tetraploidization at their inception, the vertebrates contain four times more protein-coding genes in their genome than the invertebrates: 60,000 versus 15,000. Consequently, each invertebrate gene has been amplified to the maximum of four paralogous genes in vertebrates: the one-to-four rule. When this rule is applied to genes pertinent to gonadal development and differentiation, the following emerged: (i) Two closely related zinc-finger transcription factor genes in invertebrates have been amplified to two paralogous groups in vertebrates. One consisted of EGR1, EGR2, EGR3 and EGR4, whereas the only known paralogue of the other is WT1, which controls the developmental fate of the entire nephric system, and therefore of gonads. Interestingly, EGR1 and WT1 act as antagonists of each other in nephroblastic cells. (ii) SF-1, which controls the fate of two steroid hormone-producing organs, adrenals and gonads, is descended from the invertebrate Ftz-F1 gene, and its only known paralogue is GCNF-1. (iii) The Y-linked SRY, the mammalian testis-determining gene, is a paralogue neither of SOX3 (SRX) nor of SOX9. Its ancient origin suggests that SRY once became extinct in earlier vertebrates, only to revive itself in the mammalian ancestor. (iv) Inasmuch as four paralogues of one invertebrate nuclear receptor gene have differentiated to receptors of androgen, mineralocoticoid, glucocorticoid and progesterone, there should at most be four paralogous estrogen-receptor genes in the vertebrate genome. It is likely that one of them plays a pivotal role in the estrogen-dependent sex-determining mechanism so commonly found among reptiles, amphibians and fish.

Adrenal Cortex↗
PubMed1999

Early and late postmenopausal bone loss is associated with BsmI vitamin D receptor gene polymorphism in Japanese women.

To determine whether vitamin D receptor (VDR) gene polymorphisms are associated with bone mineral density (BMD) and bone loss in the Japanese population, VDR BsmI RFLPs were analyzed in 191 postmenopausal Japanese women by comparing B allele and b allele DNA sequences, and a point mutation was confirmed. We examined VDR BsmI restriction fragment length polymorphism (RFLP) with an amplification refractory mutation system (ARMS) using this point of mutation. The frequency of VDR BsmI alleles in the Japanese population was significantly different from that in whites. The bb genotype was identified in 79.6%, of the subjects, the Bb genotype in 19.3%, and the BB genotype was in only 1.1%. We find no significant differences in lumbar spine baseline BMD between the bb genotype and the Bb genotype. In both early and late postmenopausal periods, serial measurements of vertebral BMD revealed that subjects with the Bb genotype lost BMD faster than those with the bb genotype (P = 0.001). We conclude that there is a significant relationship between RFLPs of BsmI VDR and the annual rates of bone loss during early and late postmenopausal periods in the Japanese population.

Aged↗
PubMed1999

MIC-A allele profiles and HLA class I associations in Behçet's disease.

Recently a new family of non-classical MHC molecules, the MHC class I chain-related protein (MIC), encoded by genes located in the major histocompatability complex have been identified. On the basis of the location of MIC genes and the structure and expression of MIC molecules it has been postulated that MIC may be a susceptibility factor in Behçet's disease (BD). We investigated the association of the 16 described external domain alleles and the transmembrane triplet repeats of MIC-A with BD in a Middle Eastern population. DNA from ninety-five patients and 102 age- and sex-matched controls were analyzed by polymerase chain reaction using allele specific primers. Our results show an increase of MIC-A*009 in the BD patient group 44/95 (46%) compared with controls 24/102 (24%) (chi2=11.3, OR=2.8, P=0.00078). MIC-A*009 was also found to be strongly associated with HLA-B51 in the patients 39/44 (88%) when compared with controls 10/24 (42%) (chi2=4, P=0.04). MIC-A*009 was also found in linkage disequilibrium with HLA-B52, but only in controls. The A6 form of a MIC-A transmembrane triplet repeat was found to be significantly raised in the patients (80/95; 84%;) compared with controls (58/102, 57%) (chi2=17.5, OR=4, P=0.000028). Although the MIC-A associations described are highly significant, the association with HLA-B51 independently remains the most significant factor (chi2=56.8, P<10(-6)). The data suggests that as both MIC-A*009 and A6 are in strong linkage disequilibrium with HLA-B51, they are unlikely to be the susceptibility gene for BD but may be markers for additional risk factors.

Adolescent↗
PubMed1999

Ten years' surveillance of viral conjunctivitis in Sapporo, Japan.

BACKGROUND: We set out to establish the epidemiology of viral conjunctivitis over a 10-year period in Sapporo, northern Japan. METHODS: A total of 965 patients with clinically suspected viral conjunctivitis during the 10-year period from 1985 to 1994 in Sapporo were evaluated. RESULTS: Among the 965 patients, cumulative frequency of adenovirus (Ad) was 721 (75%). The dominant serotype of Ad changed with time; each serotype peaked at 3- to 5-year intervals. Adenoviral conjunctivitis occurred most often in July and August each year. Ad3 and Ad4 were predominantly identified in patients 30-39 years old. No enterovirus 70 has been detected. Herpes simplex virus (HSV) and Chlamydia trachomatis had no significant peak. HSV was isolated throughout the year, and C. trachomatis had two peaks of detection: in March and from July to September. HSV and C. trachomatis were predominantly detected in patients 20-29 years old. CONCLUSION: In this study, the main etiological agent of viral conjunctivitis in Sapporo, Japan, was Ad; however, attention should be paid to non-adenoviral agents, such as HSV and C. trachomatis, as possible causes of acute conjunctivitis.

Adenovirus Infections, Human↗
PubMed1999

An epidemic of acute haemorrhagic conjunctivitis caused by enterovirus 70 in Okinawa, Japan, in 1994.

BACKGROUND: Although enterovirus 70 (EV70) has been identified as the major aetiological agent of acute haemorrhagic conjunctivities (ACH),no EV70 strain has been isolated by cell culture method since 1988. Therefore, recent clinical and epidemiological characteristics of AHC caused by EV70 have not been clarified. METHODS: Clinical and serological studies were carried out on patients during the AHC epidemic in Okinawa, Japan, in 1994 in which 7509 cases were reported by national epidemiological surveillance. EV70 was confirmed as the causative agent by reverse-transcription polymerase chain reaction. RESULTS: The 11-15 years age group contained the highest number of cases (62% of the total). Conjunctival hyperaemia was present in all patients, and subconjunctival haemorrhage, superficial punctate keratitis and preauricular lymphadenopathy were present in 24.0%, 11.7% and 9.3% of AHC cases, respectively. No neurological complication was observed in this epidemic. Out of 31 paired serum samples, 10 pairs showed a fourfold rise in antibody level to EV70. None of the paired serum samples showed a fourfold rise in antibody level to Coxsackie A24 variant virus. CONCLUSION: These findings demonstrate that the clinical features of AHC observed in this study were milder than those reported previously, in contrast to the high transmission rate during an epidemic. Changes in clinical features of AHC, such as a low incidence of subconjunctival haemorrhage and disappearance of neurological complications, might be due to biological transformation of EV70. It should be noted that EV70 is still an important aetiological agent of explosive epidemics of AHC.

Adolescent↗
PubMed1999

"In vivo cryotechnique" in combination with replica immunoelectron microscopy for caveolin in smooth muscle cells.

A novel "in vivo cryotechnique" with replica immunoelectron microscopy was developed for detecting caveolin localization on replica membranes prepared directly from living smooth muscle cells. After quick-freezing mouse duodenal walls by our "in vivo cryotechnique", the specimens were prepared for freeze-fracture and deep-etch replica membranes. Then they were treated with 5% SDS and 0.5% collagenase to keep some antigens on the replica membranes. The immunogold method could be used to clarify the localization of the caveolin antigen in relation to three-dimensional ultrastructures of living smooth muscle cells. Our new cryotechnique can provide native organization of functional molecules in living cells.

Animals↗
PubMed1999

Autonomic nerve tumour with skeinoid fibres: ultrastructure of skeinoid fibres examined by quick-freezing and deep-etching method.

A case of gastrointestinal autonomic nerve tumour with skeinoid fibres (SFs) of the jejunum in a 79-year-old Japanese man, was examined by the quick-freezing and deep-etching (QF-DE) method. The tumour consisted of spindle cells with immunohistochemical reactions for vimentin, NSE and CD34. Electron microscopically, features of the neural cells of the myenteric plexus were observed. The QF-DE method demonstrated intercellular meshwork structures, consisting of thin filaments (7-15 nm), with granular deposits. Fully developed parts of the deposits formed nodular aggregates composed of irregularly surfaced thick fibrils (30-48 nm) with a tendency to linear arrangement (SFs). We detected many interconnecting thin filaments (ICTFs) between the SFs, which were pre-existing components in the meshwork, avoiding the granular deposits. The focal thickening formed by the connection between SFs and ICTFs revealed a periodicity typical of SFs (33-45 nm). We conclude that SFs are formed by decoration of the granular deposits along pre-existing intercellular meshwork structures.

Abdominal Neoplasms↗
PubMed1999

Ultrastructure of rat duodenal myenteric plexus revealed by quick-freezing and deep-etching method.

A quick-freezing and deep-etching (QF-DE) method was employed with whole-mount strips of rat duodenal muscle walls to exhibit the cytoskeletons of the myenteric plexus. Nerve fibers in the myenteric plexus, which contained fewer neurofilaments than other types of neurons examined, had many varicosed contours, and were bundled by enteroglial cells. Cytoskeleton arrays were rarely observed in the varicosed regions, where synaptic vesicles were often seen, although other nerve regions contained many neurofilaments running almost in parallel with the nerve fiber bundle. Enteroglial cells had short cytoskeletons predominantly across the cytoplasm, becoming thinner the around varicosed regions of the nerve bundles. Such enteroglial extruded areas were often in close association with neighboring nerve fibers, indicating intercommunications between the nerve fibers. In distal parts of enteric nerve processes, there were numerous synaptic vesicles, but few neurofilaments. Smooth muscle cells were closely associated with the enteric nerve processes. Fine network structures, responsible for the extracellular matrix, were present between the smooth muscle cells and the enteric nerve processes. These specific structures of the myenteric plexus could be important for signalling or for the transportation of neurotransmitters involved in gut motility.

Animals↗
PubMed1999

Expression of matrix metalloproteinase-7 in choroidal neovascular membranes in age-related macular degeneration.

PURPOSE: Matrix metalloproteinases are a family of extracellular matrix-degrading enzymes associated with neovascularization. We evaluated the expression and localization of matrix metalloproteinase-7 in choroidal neovascular membranes in age-related macular degeneration. METHODS: Immunofluorescence and transmission electron microscopic examinations were performed on subfoveal neovascular membranes that had been surgically removed from seven eyes of seven patients with age-related macular degeneration. RESULTS: Matrix metalloproteinase-7 was expressed in all specimens and distinctly expressed in the thickened layer of Bruch membrane and basement membrane-like structure around retinal pigment epithelial cells. CONCLUSIONS: Matrix metalloproteinase-7 was expressed in Bruch membrane of choroidal neovascular membranes in age-related macular degeneration. Matrix metalloproteinase-7 may be an important factor for the development of the submacular neovascular membrane in age-related macular degeneration.

Aged↗
PubMed1999

Acute follicular conjunctivitis caused by adenovirus type 34.

PURPOSE: Adenovirus type 34 belongs to adenovirus subgenus B. The prototype virus of adenovirus 34 was isolated from a renal transplant recipient. However, no case of acute conjunctivitis caused by adenovirus 34 has been reported. Recently, we encountered two cases of acute follicular conjunctivitis in which adenovirus 34 was isolated. METHODS: The clinical isolates were identified by the standard neutralization test. The sequences of seven hypervariable regions in the hexon protein of these cases were compared with those of several prototype strains of adenovirus subgenus B. RESULTS: The cases were middle-aged, 34 and 41 years old, and male, and they exhibited moderate conjunctivitis with upper respiratory tract symptoms. Isolates from cell culture were identified as adenovirus 34 by NT. The mean homology rate (percentage of total number of coincident amino acids in the total length of amino acids in seven hypervariable regions) between clinical isolates and the adenovirus 34 prototype was 96.5%; in contrast, those between clinical isolates and the prototypes of adenovirus 11, adenovirus 14, and adenovirus 35 were 55.6%, 66.7%, and 57.9%, respectively. The results of conventional serotyping by neutralization test were confirmed by these values. CONCLUSIONS: These results indicate that adenovirus 34 may induce acute conjunctivitis in immunocompetent subjects and that special attention should be paid to adenovirus 34 as a causative agent for adenoviral conjunctivitis.

Acute Disease↗