71 results on '"Hiroshi Suwa"'
Search Results
2. Heart rate response to orthostatic challenge in patients with dementia with <scp>L</scp> ewy bodies and <scp>A</scp> lzheimer's disease
- Author
-
Noriko Yoshida, Hidehiko Takahashi, Yoko Suzuki, Hiroshi Suwa, Tokuhiro Kawara, Miho Miyajima, Rie Omoya, Ai Aoki, Eisuke Matsushima, Mayo Fujiwara, Takafumi Watanabe, Takashi Takeuchi, and Katsuya Ohta
- Subjects
Lewy Body Disease ,medicine.medical_specialty ,Supine position ,Disease ,Sitting ,Hypotension, Orthostatic ,03 medical and health sciences ,Orthostatic vital signs ,0302 clinical medicine ,Alzheimer Disease ,Heart Rate ,Tilt-Table Test ,Internal medicine ,mental disorders ,Heart rate ,medicine ,Humans ,In patient ,Aged ,030214 geriatrics ,Dementia with Lewy bodies ,business.industry ,medicine.disease ,Psychiatry and Mental health ,Autonomic nervous system ,Cross-Sectional Studies ,Cardiology ,Geriatrics and Gerontology ,business ,Gerontology ,030217 neurology & neurosurgery - Abstract
Background To elucidate the differences in autonomic dysfunction between dementia with Lewy bodies (DLB) and Alzheimer's disease using a simple and convenient method, we investigated the heart rate response to orthostatic challenge. Methods Ninety-seven people participated in this cross-sectional study, and data from 26 DLB patients, 29 Alzheimer's disease patients, and 25 healthy elderly individuals were analysed. Participants underwent postural changes, including 5 min in a supine position, 1 min in a sitting position, and 3 min in an orthostatic position. Their heart rates were continuously recorded. Two heart rate variables were analysed as main outcomes: (i) the difference between heart rate in the sitting position and the peak heart rate within 15 s of orthostasis, defined as the 'early heart rate increase'; and (ii) the difference between the peak heart rate and the negative peak heart rate after this, defined as 'early heart rate recovery.' An early heart rate increase has been considered to reflect parasympathetic and sympathetic functions. Early heart rate recovery is considered to reflect parasympathetic function. We also investigated the frequency domains of resting heart rate variability. Results A significant difference was observed across the three groups in early heart rate increase, and that of the DLB group was lower than that of the healthy control group. Early heart rate recovery also differed significantly across the three groups, and that of the DLB group was less than that of the healthy control group. In addition, the power of the low-frequency component, which represents both sympathetic and parasympathetic activity, was significantly decreased in the DLB group compared to the Alzheimer's disease group. Conclusions Impaired heart rate response to standing was detected in patients with DLB. Electrocardiogram is a convenient, non-invasive method that might be useful as a subsidiary marker for DLB diagnosis and differentiation from Alzheimer's disease.
- Published
- 2020
- Full Text
- View/download PDF
3. Is prolongation of corrected QT interval associated with seizures induced by electroconvulsive therapy reduced by atropine sulfate?
- Author
-
Tokuhiro Kawara, Issei Murata, Katsuya Ohta, Noriko Yoshida, Takeshi Sasaki, Masato Matsuura, Eisuke Matsushima, Shigeru Ozaki, Takafumi Watanabe, Rie Omoya, Hiroshi Suwa, Mitsuru Nakamura, Yoko Suzuki, Hiroaki Yamazaki, Tetsuo Sasano, Mayo Fujiwara, Masaki Okumura, Masayuki Shintaku, and Miho Miyajima
- Subjects
Atropine ,Male ,QTC PROLONGATION ,congenital, hereditary, and neonatal diseases and abnormalities ,medicine.medical_specialty ,Ventricular Repolarization ,Bipolar Disorder ,medicine.medical_treatment ,030204 cardiovascular system & hematology ,QT interval ,Electrocardiography ,03 medical and health sciences ,0302 clinical medicine ,Electroconvulsive therapy ,Heart Rate ,Risk Factors ,Seizures ,Internal medicine ,mental disorders ,Heart rate ,medicine ,Atropine sulfate ,Humans ,cardiovascular diseases ,Electroconvulsive Therapy ,Aged ,Depressive Disorder, Major ,business.industry ,Prolongation ,Corrected qt ,Electroencephalography ,General Medicine ,030227 psychiatry ,Long QT Syndrome ,Treatment Outcome ,cardiovascular system ,Cardiology ,Female ,Cardiology and Cardiovascular Medicine ,business ,Anti-Arrhythmia Agents ,circulatory and respiratory physiology - Abstract
Background Electrocardiogram abnormalities have been reported during electroconvulsive therapy (ECT). A corrected QT interval (QTc) prolongation indicates delayed ventricular repolarization, which can trigger ventricular arrhythmias such as torsade de pointes (TdP). We examined the QTc changes during generalized tonic-clonic seizures induced by ECT, and the effects of atropine sulfate on these QTc changes. Methods We analyzed heart rate, QT interval, and QTc in 32 patients with depression who underwent ECT (25 women, 67.4 ± 8.7 years of age). The QTc from -30 to 0 seconds prestimulation was used as baseline, which was compared with QTc at 20-30 seconds and 140-150 seconds poststimulus onset. Results QTc was significantly prolonged at 20-30 seconds poststimulus, then significantly decreased at 140-150 seconds poststimulus, compared with baseline. QTc prolongation induced by ECT was significantly decreased by atropine sulfate. Conclusions These data suggest that the risk of TdP may be enhanced by ECT. Further, the risk of cardiac ventricular arrhythmias, including TdP, may be reduced by administration of atropine sulfate.
- Published
- 2017
- Full Text
- View/download PDF
4. Pulsation in Debris Flows and its Mechanism
- Author
-
Hiroshi Suwa
- Subjects
010504 meteorology & atmospheric sciences ,Geotechnical engineering ,010502 geochemistry & geophysics ,01 natural sciences ,Debris ,Geology ,Mechanism (sociology) ,0105 earth and related environmental sciences - Published
- 2017
- Full Text
- View/download PDF
5. Slope hydrology controlling sediment discharge and landslide processes
- Author
-
Hiroshi Suwa
- Subjects
010504 meteorology & atmospheric sciences ,Environmental science ,010502 geochemistry & geophysics ,01 natural sciences ,0105 earth and related environmental sciences - Published
- 2017
- Full Text
- View/download PDF
6. Subjectivity disorder as the fundamental disorder in schizophrenia: Analysis of exploratory eye movements
- Author
-
Masahiro Suzuki, Hiroshi Suwa, Misuzu Sakurada, Katsumi Mori, Takuya Kojima, Sakae Takahashi, and Eisuke Matsushima
- Subjects
Subjectivity ,Eye Movements ,General Neuroscience ,Schizophrenia (object-oriented programming) ,Eye movement ,Fixation, Ocular ,General Medicine ,Psychiatry and Mental health ,Neurology ,Exploratory Behavior ,Visual Perception ,Humans ,Schizophrenic Psychology ,Neurology (clinical) ,Psychology ,Psychomotor Performance ,Cognitive psychology - Published
- 2019
- Full Text
- View/download PDF
7. Reduced N-acetylaspartate in the hippocampus in patients with fibromyalgia: A meta-analysis
- Author
-
Ryota Inokuchi, Hiroshi Suwa, and Yuta Aoki
- Subjects
Adult ,Oncology ,medicine.medical_specialty ,Fibromyalgia ,Magnetic Resonance Spectroscopy ,Databases, Factual ,Neuroscience (miscellaneous) ,Hippocampus ,Internal medicine ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,In patient ,N-acetylaspartate ,Aspartic Acid ,Cognition ,Middle Aged ,medicine.disease ,Pathophysiology ,Psychiatry and Mental health ,nervous system ,Meta-analysis ,Abnormality ,Psychology ,Neuroscience - Abstract
Fibromyalgia (FM) is a stress-associated syndrome with chronic, widespread pain. Patients with FM also present disturbances of cognition and memory. As the hippocampus is vulnerable to stress exposure and involved in cognition, memory and pain perception, we hypothesize that the abnormal function of the hippocampus is implicated in the pathophysiology of FM. N-acetylaspartate (NAA), a metabolite that can be measured using proton magnetic resonance spectroscopy (1H MRS), is recognized as a marker of neuronal structure and function. We performed a systematic review and meta-analysis of 1H MRS studies investigating NAA levels in patients with FM. A comprehensive literature search through MEDLINE, Embase and Web of Science yielded nine studies; among these nine, four studies met our criteria for inclusion. A random effect model with 51 patients with FM and 38 controls revealed a significant NAA reduction in the hippocampus. The current meta-analysis suggested a neuronal abnormality in the hippocampus in patients with FM.
- Published
- 2013
- Full Text
- View/download PDF
8. Age-related change of neurochemical abnormality in attention-deficit hyperactivity disorder: A meta-analysis
- Author
-
Yuta Aoki, Ryota Inokuchi, Ai Aoki, and Hiroshi Suwa
- Subjects
Aging ,medicine.medical_specialty ,Magnetic Resonance Spectroscopy ,Cognitive Neuroscience ,Prefrontal Cortex ,behavioral disciplines and activities ,Correlation ,Behavioral Neuroscience ,Neurochemical ,Internal medicine ,Age related ,mental disorders ,medicine ,Humans ,Attention deficit hyperactivity disorder ,Prefrontal cortex ,Aspartic Acid ,Methylphenidate ,Age Factors ,medicine.disease ,Neuropsychology and Physiological Psychology ,Endocrinology ,nervous system ,Attention Deficit Disorder with Hyperactivity ,Meta-analysis ,Abnormality ,Psychology ,Neuroscience ,medicine.drug - Abstract
Prevalence and symptoms of attention-deficit hyperactivity disorder (ADHD) change with advancing age. However, neurochemical background of such age-related change is yet to be elucidated. We therefore conducted a meta-analysis of 16 proton magnetic resonance spectroscopy studies comprising 270 individuals with ADHD and 235 controls. Standardized mean differences were calculated and used as an effect size. Sensitivity analyses and meta-regression to explore the effect of age on neurochemical abnormality were performed. A random effects model identified a significantly higher-than-normal N-acetylaspartate (NAA) in the medial prefrontal cortex (mPFC), but no significant differences of other metabolites in that area. No significant difference in metabolite levels was demonstrated in any other region. Sensitivity analysis of children with ADHD revealed significantly higher-than-normal NAA, whereas no significant difference was found in adults with ADHD. Meta-regression revealed significant correlation between advanced age and normal levels of NAA in the mPFC, suggesting that age-dependent abnormality of NAA level in the mPFC is a potential neural basis of age-related change of symptoms of ADHD.
- Published
- 2013
- Full Text
- View/download PDF
9. The Validity and Usefulness of the Japanese Version of the Calgary Sleep Apnea Quality of Life Index in Patients with Obstructive Sleep Apnea Hypopnea Syndrome
- Author
-
Motonori Kobayashi, Eisuke Matsushima, Hiroshi Suwa, and Mika Kobayashi
- Subjects
Adult ,Cross-Cultural Comparison ,Male ,medicine.medical_specialty ,Polysomnography ,medicine.medical_treatment ,Japan ,Quality of life ,Surveys and Questionnaires ,Internal Medicine ,medicine ,Humans ,In patient ,Continuous positive airway pressure ,Language ,Sleep Apnea, Obstructive ,Continuous Positive Airway Pressure ,business.industry ,Epworth Sleepiness Scale ,Reproducibility of Results ,Sleep apnea ,Construct validity ,General Medicine ,Middle Aged ,medicine.disease ,humanities ,Obstructive sleep apnea ,Quality of Life ,Physical therapy ,Female ,business ,Hypopnea - Abstract
OBJECTIVE The main purpose of this study was to translate the Calgary sleep apnea quality of life index (SAQLI) and to evaluate the reliability, validity and responsiveness of the Japanese version of the SAQLI (SAQLI-J). METHODS Translation of the SAQLI questionnaire into the SAQLI-J questionnaire was performed following the guidelines of cross-cultural adaptation of health-related quality of life (QOL) measures. All patients completed the following questionnaires both at baseline and three months later: the SAQLI-J, the medical outcome survey short form (SF-36) and the Epworth sleepiness scale (ESS). The SAQLI-J was conducted by an interviewer. PATIENTS One hundred and fifteen obstructive sleep apnea hypopnea syndrome (OSAHS) patients were recruited into the present study. RESULTS The internal consistency and test-retest reliability of the total SAQLI-J scores (SAQLI-J total) were both excellent. Regarding construct validity, the SAQLI-J was tested by measuring the inter-domain correlation between the SAQLI-J domains and the SF-36 domains. All of the SAQLI-J domains and the SAQLI-J total were found to be moderately to highly correlated with the domains of the SF-36. Moreover, the responsiveness of the SAQLI-J total measured according to the standardized response mean was found to be moderate, and the SAQLI-J was found to be more responsive than the SF-36 for detecting changes in the QOL after continuous positive airway pressure treatment. CONCLUSION The results suggest that the SAQLI-J is a valid, reliable and responsive health-related QOL questionnaire for use in Japanese OSAHS patients.
- Published
- 2013
- Full Text
- View/download PDF
10. Diffusion tensor imaging studies of mild traumatic brain injury: a meta-analysis
- Author
-
Hiroshi Suwa, Masataka Gunshin, Yuta Aoki, Ryota Inokuchi, and Naoki Yahagi
- Subjects
Pathology ,medicine.medical_specialty ,Traumatic brain injury ,Corpus callosum ,Splenium ,Neuroimaging ,Nerve Fibers, Myelinated ,White matter ,systematic review ,Fractional anisotropy ,medicine ,Humans ,human ,business.industry ,Neuropsychiatry ,medicine.disease ,meta-analysis ,Psychiatry and Mental health ,Diffusion Tensor Imaging ,medicine.anatomical_structure ,Brain Injuries ,Meta-analysis ,Anisotropy ,Surgery ,Neurology (clinical) ,Nuclear medicine ,business ,Psychology ,fractional anisotropy ,Diffusion MRI - Abstract
Objectives To assess the possibility that diffusion tensor imaging (DTI) can detect white matter damage in mild traumatic brain injury (mTBI) patients via systematic review and meta-analysis. Methods DTI studies that compared mTBI patients and controls were searched using MEDLINE, Web of Science, and EMBASE, (1980 through April 2012). Results A comprehensive literature search identified 28 DTI studies, of which 13 independent DTI studies of mTBI patients were eligible for the meta-analysis. Random effect model demonstrated significant fractional anisotropy (FA) reduction in the corpus callosum (CC) (p¼0.023, 95% CIs � 0.466 to � 0.035, 280 mTBIs and 244 controls) with no publication bias and minimum heterogeneity, and a significant increase in mean diffusivity (MD) (p¼0.015, 95% CIs 0.062 to 0.581, 154 mTBIs and 100 controls). Meta-analyses of the subregions of the CC demonstrated in the splenium FA was significantly reduced (p¼0.025, 95% CIs � 0.689 to � 0.046) and MD was significantly increased (p¼0.013, 95% CIs 0.113 to 0.950). FA was marginally reduced in the midbody (p¼0.099, 95% CIs � 0.404 to 0.034), and no significant change in FA (p¼0.421, 95% CIs � 0.537 to 0.224) and MD (p¼0.264, 95% CIs � 0.120 to 0.438) in the genu of the CC. Conclusions Our meta-analysis revealed the posterior part of the CC was more vulnerable to mTBI compared with the anterior part, and suggested the potential utility of DTI to detect white matter damage in the CC of mTBI patients.
- Published
- 2012
- Full Text
- View/download PDF
11. Prediction of a landslide and analysis of slide motion with reference to the 2004 Ohto slide in Nara, Japan
- Author
-
Takayuki Ishii, Hiroshi Suwa, and Takashi Mizuno
- Subjects
Seismometer ,Creep ,Typhoon ,Slope stability ,Landslide ,Geology ,Seismology ,Seismic wave ,Earth-Surface Processes ,Extensometer ,Downhill creep - Abstract
A slope 120 m wide and 100 m high collapsed including the roadbed of a national highway of Route 168 at Ohto, Nara, Japan on August 10, 2004. The precursory phenomena of abnormal features were found as cracks growing on the road-side slope 7 months before the catastrophe. The movements of the slope were monitored by extensometers. The data of the extensometers showed that creep mode turned from the secondary into the tertiary due to the heavy rainstorm of Typhoon Namtheun. The slide claimed no victims because the highway was closed 43 h before the catastrophe, anticipating a possible hazard when the creep velocity reached 4 mm/2 h. Comparison of rupture time predictions suggested that precision of the prediction using the reciprocal of creep velocity is higher than that by tertiary creep analysis, although leaving a problem that the prediction of the time zone of failure erred on the dangerous side. The slide generated ground vibration which was observed by seismometers deployed around the slide. Duration of the seismic signals corresponded well with the slide motion deciphered from video records. We found the fact that the seismic energy radiation from a landslide consisted of four stages. This had not been reported in any previous study, and may be important in understanding the dynamics of a rock-slide avalanche.
- Published
- 2010
- Full Text
- View/download PDF
12. Behavior of debris flows monitored on test slopes of Kamikamihorizawa Creek, Mount Yakedake, Japan
- Author
-
Hiroshi Suwa, Tadahiro Kanno, and Kazuyuki Okano
- Subjects
Hydrology ,geography ,geography.geographical_feature_category ,Volcano ,Debris ,Geomorphology ,Mount ,Geology ,Debris flow - Published
- 2009
- Full Text
- View/download PDF
13. Sequential processes in a landslide hazard at a slate quarry in Okayama, Japan
- Author
-
S. Suzuki, T. Mizuno, Hiroshi Suwa, Y. Yamamoto, and K. Ito
- Subjects
Seismometer ,Dip slope ,Atmospheric Science ,Bedding ,Bed ,Natural hazard ,Earth and Planetary Sciences (miscellaneous) ,Landslide ,Geology ,Aftershock ,Seismology ,Water Science and Technology ,Foreshock - Abstract
The 12 March 2001 landslide at a slate quarry in Okayama, Japan killed three workers. Composite studies based on field surveys of the landslide slope, interviews with local residents and quarry workers, and inspections of hydrological and seismological data have been used to clarify the causes of this slide and its movements. The results indicate that the landslide was enabled firstly by the steepness of the slope, which had been undercut by river; secondly, the structure was that of a dip-slope that was prone to deep-seated slides along bedding planes; thirdly, numerous joints and faults were present. Surprisingly, rainfall, earthquakes, and explosions do not appear to have played any role in the triggering of this slide. The interviews demonstrated that the frequency of precursory failures increased over a period of several hours before the 12 March 2001 landslide. Inspection of the seismograph records and the eyewitness evidence both indicate that the main part of the landslide consisted of two phases of slope failure within 23 s. After the slide, the frequency of the failures gradually decreased with time over a period of several days. Three new terms are proposed for landslides: foreslide, mainslide, and afterslide, following the terms foreshock, main shock, and aftershock used in seismology.
- Published
- 2008
- Full Text
- View/download PDF
14. Wear Resistance of Multi-Layer Interlocked Fabric Reinforced COPNA Resin Composite
- Author
-
Hiroshi Suwa, Michiya Ota, Nobuyuki Ishikawa, and Akira Kojima
- Subjects
Friction coefficient ,Wear resistance ,High wear resistance ,Materials science ,law ,Resin composite ,General Medicine ,Graphite ,Composite material ,Multi layer ,Cylinder (engine) ,law.invention - Abstract
Two kinds of multi-layer interlocked fabric with different fabric structures were made of pitch-based carbon fiber, and the fabric was combined with condensed polynuclear aromatic (COPNA) resin to prepare multi-layer interlocked fabric reinforced COPNA resin composites. In addition, a third type of material was prepared by adding graphite to the composite material. The wear resistance of these composite materials was evaluated under both high and low loading conditions by means of the cylinder/flat plate friction tester. The following results were obtained. In case of the composite material including graphite, at low loads the friction coefficient was low, and the wear resistance was high. However, at high loads the strength of the material was reduced due to the presence of graphite, and the sample failed. In case of composite materials made without graphite, the influence of the loading condition was small, and stable, high wear resistance was observed under conditions at both high and low loads. A higher wear resistance was observed in the case where the fibers were homogeneously distributed on the sliding surface of the composite material than in case where they were heterogeneously distributed.
- Published
- 2007
- Full Text
- View/download PDF
15. Friction Property of Multi-Layer Interlocked Fabric Reinforced COPNA Resin Composite
- Author
-
Hiroshi Suwa, Akira Kojima, and Michiya Ota
- Subjects
Composite epoxy material ,Thermal conductivity ,Materials science ,law ,Resin composite ,General Medicine ,Composite material ,Material properties ,Multi layer ,Heat flow ,Fabric structure ,Cylinder (engine) ,law.invention - Abstract
Composite materials were made from multi-layer interlocked fabrics which were woven with pitch-based carbon fiber rovings and COPNA resin matrix. Thermal conductivity of the composite materials were measured by guarded heat flow meter method and transient hot wire method. Limiting PV value of the composite materials were measured by using cylinder/plate friction machine. Then, the relation ship between the structure of multi-layer interlocked fabric and those properties of materials was investigated. The result are summarized as follows; The thermal conductivity and limiting PV value of composite materials were higher than those of single COPNA resin material. It was found that self-lubrication of the composite materials was effectively expressed by the fabric structure with carbon fiber rovings highly dispersed.
- Published
- 2006
- Full Text
- View/download PDF
16. Improvement of Thermal Conductivity of CFRP by Multi-Layer Interlocked Fabric
- Author
-
Michiya Ota, Hiroshi Suwa, Nobuyuki Ishikawa, and Akira Kojima
- Subjects
Thermal conductivity ,Materials science ,General Medicine ,Composite material ,Fibre-reinforced plastic ,Multi layer - Abstract
Carbon fiber reinforced plastic (CFRP) materials were made from multi-layer interlocked fabrics which were woven with Abstract
- Published
- 2005
- Full Text
- View/download PDF
17. Mutations affecting gonadal development in Medaka, Oryzias latipes
- Author
-
Tomomi Watanabe, Hisato Kondoh, Norimasa Iwanami, Toshiyuki Yamanaka, Chikako Morinaga, Takao Sasado, Katsutoshi Niwa, Takeshi Tomonaga, Hiroki Yoda, Ai Shinomiya, Hiroshi Suwa, Sanae Kunimatsu, Yasuko Okamoto, Yukihiro Hirose, Akihito Yasuoka, Makoto Furutani-Seiki, Thorsten Henrich, Minoru Tanaka, and Tomonori Deguchi
- Subjects
Genetics ,Male ,endocrine system ,Embryology ,Gonad ,Sexual differentiation ,biology ,Somatic cell ,Oryzias ,Mutant ,biology.organism_classification ,Molecular biology ,medicine.anatomical_structure ,Germ Cells ,Phenotype ,Mutation ,medicine ,Animals ,Female ,Development of the gonads ,Gonads ,Gene ,Germ cell ,Developmental Biology - Abstract
A gonad is formed from germ cells and somatic mesodermal cells through their interactions. Its development is coupled with the determination and differentiation of the sex and sex-associated traits. We carried out a large-scale screening of Medaka mutants in which gonadal development is affected. Screening was performed on larvae at 8 days posthatching for abnormal abundance and/or distribution of germ cells detected by the in situ hybridization for olvas (Medaka vasa). We describe here 16 mutants of 13 genes, which are classified into four groups. Group 1, consisting of four mutants of three genes kon, tot) characterised by an increase in germ cell number. An adult tot homozygote fish has the characteristic feature of possessing hypertrophic gonads filled with immature oocytes. Group 2, represented by a single gene (zen) mutant characterized by a gradual loss of germ cells. Group 3, consisting of four mutants of distinct genes (eko, eki, sht, ano) showing irregular clustering of germ cells. Group 4, consisting of seven mutants of five genes (arr, hyo, mzr, hdr, fbk) showing fragmented clusters of germ cells. In some mutants belonging to Groups 1, 3 and 4, the expression level of ftz-f1 (sf-1/Ad4BP) in gonadal somatic cells significantly decreased, suggesting that interaction between somatic and germ cells is affected.
- Published
- 2004
- Full Text
- View/download PDF
18. Mutations affecting liver development and function in Medaka, Oryzias latipes, screened by multiple criteria
- Author
-
Yukihiro Hirose, Akihito Yasuoka, Hiroshi Nishina, Felix Loosli, Hiroshi Suwa, Clemens Grabher, Katsutoshi Niwa, Satoshi Asaka, Hiroki Yoda, Takao Sasado, Kota Saito, Rebecca Quiring, Matthias Carl, Sanae Kunimatsu, Keiko Abe, Daiju Kitagawa, Tomonori Deguchi, Chikako Morinaga, Thorsten Henrich, Masakazu Osakada, Sylke Winkler, Tomomi Watanabe, Ryumei Kurashige, Katsuhito Takahashi, Yousuke Takahama, Hisato Kondoh, Joachim Wittbrodt, Toshiaki Katada, Norimasa Iwanami, Makoto Furutani-Seiki, and Filippo Del Bene
- Subjects
Genetics ,Mutation ,Embryology ,Liver morphogenesis ,Endoderm ,Mutant ,Oryzias ,Gallbladder ,Mutagenesis (molecular biology technique) ,Biology ,Lipid Metabolism ,medicine.disease_cause ,Phenotype ,Complementation ,Liver ,Endoderm formation ,medicine ,Animals ,Gene ,In Situ Hybridization ,Body Patterning ,Developmental Biology - Abstract
We report here mutations affecting various aspects of liver development and function identified by multiple assays in a systematic mutagenesis screen in Medaka. The 22 identified recessive mutations assigned to 19 complementation groups fell into five phenotypic groups. Group 1, showing defective liver morphogenesis, comprises mutations in four genes, which may be involved in the regulation of growth or patterning of the gut endoderm. Group 2 comprises mutations in three genes that affect the laterality of the liver; in kendama mutants of this group, the laterality of the heart and liver is uncoupled and randomized. Group 3 includes mutations in three genes altering bile color, indicative of defects in hemoglobin-bilirubin metabolism and globin synthesis. Group 4 consists of mutations in three genes, characterized by a decrease in the accumulation of fluorescent metabolite of a phospholipase A(2) substrate, PED6, in the gall bladder. Lipid metabolism or the transport of lipid metabolites may be affected by these mutations. Mutations in Groups 3 and 4 may provide animal models for relevant human diseases. Group 5 mutations in six genes affect the formation of endoderm, endodermal rods and hepatic bud from which the liver develops. These Medaka mutations, identified by morphological and metabolite marker screens, should provide clues to understanding molecular mechanisms underlying formation of a functional liver.
- Published
- 2004
- Full Text
- View/download PDF
19. Identification of radiation-sensitive mutants in the Medaka, Oryzias latipes
- Author
-
Chikako Morinaga, Hiroki Yoda, Tomonori Deguchi, Hiroshi Mitani, Hisato Kondoh, Akihiro Shima, Akihito Yasuoka, Thorsten Hennrich, Masakazu Osakada, Katsutoshi Niwa, Yukihiro Hirose, Takao Sasado, Atsuko Shimada, Makoto Furutani-Seiki, Norimasa Iwanami, Nozomi Kogure, Sanae Kunimatsu, Hiroshi Suwa, Tomomi Watanabe, Takeshi Todo, and Kouichi Aizawa
- Subjects
Tail ,Genome instability ,Embryology ,Time Factors ,animal structures ,DNA Repair ,DNA repair ,Oryzias ,Mutant ,Apoptosis ,Radiation Tolerance ,Genomic Instability ,Midblastula ,Animals ,biology ,Embryo ,Gastrula ,biology.organism_classification ,Molecular biology ,Double Strand Break Repair ,Comet assay ,Gamma Rays ,Mutation ,embryonic structures ,Comet Assay ,Developmental Biology - Abstract
We screened populations of N-ethyl-N-nitrosourea (ENU)-mutagenized Medaka, (Oryzias latipes) for radiation-sensitive mutants to investigate the mechanism of genome stability induced by ionizing radiation in developing embryos. F3 embryos derived from male founders that were homozygous for induced the mutations were irradiated with gamma-rays at the organogenesis stage (48hpf) at a dose that did not cause malformation in wild-type embryos. We screened 2130 F2 pairs and identified three types of mutants with high incidence of radiation-induced curly tailed (ric) malformations using a low dose of irradiation. The homozygous strain from one of these mutants, ric1, which is highly fertile and easy to breed, was established and characterized related to gamma-irradiation response. The ric1 strain also showed higher incidence of malformation and lower hatchability compared to the wild-type CAB strain after gamma-irradiation at the morula and pre-early gastrula stages. We found that the decrease in hatching success after gamma-irradiation, depends on the maternal genotype at the ric1 locus. Terminal deoxynucleotidyl transferase-mediated deoxy-UTP nick end-labeling assays showed a high frequency of apoptosis in the ric1 embryos immediately after gamma-irradiation at the pre-early gastrula stage but apoptotic cells were not observed before midblastula transition (MBT). The neutral comet assay revealed that the ric1 mutant has a defect in the rapid repair of DNA double-strand breaks induced by gamma-rays. These results suggest that RIC1 is involved in the DNA double strand break repair in embryos from morula to organogenesis stages, and unrepaired DNA double strand breaks in ric1 trigger apoptosis after MBT. These results support the use of the ric1 strain for investigating various biological consequences of DNA double strand breaks in vivo and for sensitive monitoring of genotoxicity related to low dose radiation.
- Published
- 2004
- Full Text
- View/download PDF
20. Mutations affecting thymus organogenesis in Medaka, Oryzias latipes
- Author
-
Sanae Kunimatsu, Tomonori Deguchi, Rie Takei, Thorsten Henrich, Chikako Morinaga, Yousuke Takahama, Yukihiro Hirose, Takao Sasado, Katsutoshi Niwa, Akihito Yasuoka, Hiroki Yoda, Osamu Ohara, Hisato Kondoh, Norimasa Iwanami, Yuko Ishikura, Hiroshi Suwa, Makoto Furutani-Seiki, and Jie Li
- Subjects
Genetics ,Embryology ,biology ,Genes, RAG-1 ,Lymphocyte ,Oryzias ,Mutant ,Gene Expression ,Gene Expression Regulation, Developmental ,Mutagenesis (molecular biology technique) ,Organogenesis ,Thymus Gland ,T lymphocyte ,biology.organism_classification ,Recombination-activating gene ,Cell biology ,Branchial Region ,medicine.anatomical_structure ,Mutation ,medicine ,Animals ,Pharyngeal arch ,Developmental Biology - Abstract
The thymus is an organ for T lymphocyte maturation and is indispensable for the establishment of a highly developed immune system in vertebrates. In order to genetically dissect thymus organogenesis, we carried out a large-scale mutagenesis screening for Medaka mutations affecting recombination activating gene 1 (rag1) expression in the developing thymus. We identified 24 mutations, defining at least 13 genes, which led to a marked reduction of rag1 expression in the thymus. As thymus development depends on pharyngeal arches, we classified those mutations into three classes according to the defects in the pharyngeal arches. Class 1 mutants had no or slight morphological abnormalities in the pharyngeal arches, implying that the mutations may include defects in such thymus-specific events as lymphocyte development and thymic epithelial cell maturation. Class 2 mutants had abnormally shaped pharyngeal arches. Class 3 mutants showed severely attenuated pharyngeal arch development. In Class 2 and Class 3 mutants, the defects in thymus development may be due to abnormal pharyngeal arch development. Those mutations are expected to be useful for identifying the molecular mechanisms underlying thymus organogenesis.
- Published
- 2004
- Full Text
- View/download PDF
21. Mutations affecting retina development in Medaka
- Author
-
Felix Loosli, Rebecca Quiring, Hiroshi Suwa, Harun Elmasri, Caroline Iquel, Chikako Morinaga, Sanae Kunimatsu, Katsutoshi Niwa, Christoph Winkler, Clemens Grabher, Yukihiro Hirose, Annette Krone, Thorsten Henrich, Filippo Del Bene, Tomonori Deguchi, Beate Wittbrodt, Matthias Carl, Sylke Winkler, Akihito Yasuoka, Takao Sasado, Masakazu Osakada, Juan Ramón Martínez-Morales, Hisato Kondoh, Martina Rembold, Joachim Wittbrodt, Tomomi Watanabe, Makoto Furutani-Seiki, Hiroki Yoda, Norimasa Iwanami, Roche, Japan Science and Technology Agency, Company of Biologists, Boehringer Ingelheim Fonds, Marie Curie Memorial Foundation, German Research Foundation, and European Commission
- Subjects
Embryology ,genetic structures ,Teleost ,Mutant ,Oryzias ,Mutagenesis (molecular biology technique) ,Genes, Recessive ,Biology ,Optic cup (anatomical) ,medicine.disease_cause ,Eye ,Retina ,Optic vesicle formation ,medicine ,Animals ,Genetics ,Mutation ,Pigmentation ,Cell Differentiation ,Large scale ,Optic vesicle ,eye diseases ,Medaka ,medicine.anatomical_structure ,Mutagenesis ,sense organs ,Neural plate ,Developmental Biology - Abstract
12 páginas, 5 figuras, 1 tabla.-- et al., In a large scale mutagenesis screen of Medaka we identified 60 recessive zygotic mutations that affect retina development. Based on the onset and type of phenotypic abnormalities, the mutants were grouped into five categories: the first includes 11 mutants that are affected in neural plate and optic vesicle formation. The second group comprises 15 mutants that are impaired in optic vesicle growth. The third group includes 18 mutants that are affected in optic cup development. The fourth group contains 13 mutants with defects in retinal differentiation. 12 of these have smaller eyes, whereas one mutation results in enlarged eyes. The fifth group consists of three mutants with defects in retinal pigmentation. The collection of mutants will be used to address the molecular genetic mechanisms underlying vertebrate eye formation., This work was supported by the Roche Research Foundation (F.L.) the Japanese Agency for Science and Technology (JST) (R.Q., M.C., S.W.), the Company of Biologists Ltd (F.D.B.), the Boehringer Ingelheim Foundation (C.G.), the Marie Curie Foundation (J-R. M-M.) and through grants from the DFG, EC (J.W) and HFSP (H.K, J.W.).
- Published
- 2004
- Full Text
- View/download PDF
22. A systematic genome-wide screen for mutations affecting organogenesis in Medaka, Oryzias latipes
- Author
-
Katsutoshi Niwa, Harun Elmasri, Toshiaki Katada, Norimasa Iwanami, Makoto Furutani-Seiki, Yasuko Okamoto, Tomonori Deguchi, Noboru Nakajima, Akihito Yasuoka, Yukihiro Hirose, Yousuke Takahama, Clemens Grabher, Ai Shinomiya, Yasuko Kota, Sanae Kunimatsu, Hisato Kondoh, Hiroshi Mitani, Akihiro Momoi, Tomomi Watanabe, Rebecca Quiring, Katsuhito Takahashi, Hiroshi Nishina, Toshiyuki Yamanaka, Joachim Wittbrodt, Hiroki Yoda, Takeshi Todo, Hiroshi Suwa, Kota Saito, Daiju Kitagawa, Sylke Winkler, Keiko Abe, Chikako Morinaga, Matthias Carl, Satoshi Asaka, Thorsten Henrich, Minoru Tanaka, Filippo Del Bene, Takao Sasado, Masakazu Osakada, Mirana Ramialison, Christoph Winkler, and Felix Loosli
- Subjects
Embryology ,animal structures ,DNA repair ,Oryzias ,Organogenesis ,Mutagenesis (molecular biology technique) ,Thymus Gland ,Eye ,Radiation Tolerance ,Prosencephalon ,Animals ,Zebrafish ,Gene ,Genetics ,biology ,fungi ,biology.organism_classification ,Phenotype ,Germ cell migration ,Germ Cells ,Somites ,Research Design ,embryonic structures ,Mutation ,Nerve tract ,Developmental Biology - Abstract
A large-scale mutagenesis screen was performed in Medaka to identify genes acting in diverse developmental processes. Mutations were identified in homozygous F3 progeny derived from ENU-treated founder males. In addition to the morphological inspection of live embryos, other approaches were used to detect abnormalities in organogenesis and in specific cellular processes, including germ cell migration, nerve tract formation, sensory organ differentiation and DNA repair. Among 2031 embryonic lethal mutations identified, 312 causing defects in organogenesis were selected for further analyses. From these, 126 mutations were characterized genetically and assigned to 105 genes. The similarity of the development of Medaka and zebrafish facilitated the comparison of mutant phenotypes, which indicated that many mutations in Medaka cause unique phenotypes so far unrecorded in zebrafish. Even when mutations of the two fish species cause a similar phenotype such as one-eyed-pinhead or parachute, more genes were found in Medaka than in zebrafish that produced the same phenotype when mutated. These observations suggest that many Medaka mutants represent new genes and, therefore, are important complements to the collection of zebrafish mutants that have proven so valuable for exploring genomic function in development.
- Published
- 2004
- Full Text
- View/download PDF
23. Mutations affecting retinotectal axonal pathfinding in Medaka, Oryzias latipes
- Author
-
Tomomi Watanabe, Hiroshi Suwa, Joachim Wittbrodt, Norimasa Iwanami, Yukihiro Hirose, Tomonori Deguchi, Hisato Kondoh, Sanae Kunimatsu, Toshiyuki Yamanaka, Thorsten Henrich, Hiroki Yoda, Makoto Furutani-Seiki, Yasuko Okamoto, Chikako Morinaga, Masakazu Osakada, Takao Sasado, Katsutoshi Niwa, and Akihito Yasuoka
- Subjects
Superior Colliculi ,Embryology ,Oryzias ,Mutant ,Biology ,Eye ,medicine.disease_cause ,Retinal ganglion ,chemistry.chemical_compound ,medicine ,Animals ,Zebrafish ,Mutation ,Retina ,fungi ,Optic Nerve ,Retinal ,Anatomy ,biology.organism_classification ,Phenotype ,Axons ,eye diseases ,Cell biology ,medicine.anatomical_structure ,nervous system ,chemistry ,Optic Chiasm ,sense organs ,Tectum ,Developmental Biology - Abstract
We screened for mutations affecting retinotectal axonal projection in Medaka, Oryzias latipes. In wild-type Medaka embryos, all the axons of retinal ganglion cells (RGCs) project to the contralateral tectum, such that the topological relationship of the retinal field is maintained. We labeled RGC axons using DiI/DiO at the nasodorsal and temporoventral positions of the retina, and screened for mutations affecting the pattern of stereotypic projections to the tectum. By screening 184 mutagenized haploid genomes, seven mutations in five genes causing defects in axonal pathfinding were identified, whereas mutations affecting the topographic projection of RGC axons were not found. The mutants were grouped into two classes according to their phenotypes. In mutants of Class I, a subpopulation of the RGC axons branched out either immediately after leaving the eye or after reaching the midline, and this axonal subpopulation projected to the ipsilateral tectum. In mutants of Class II, subpopulations of RGC axons branched out after crossing the midline and projected aberrantly. These mutants will provide clues to understanding the functions of genes essential for axonal pathfinding, which may be conserved or partly divergent among vertebrates.
- Published
- 2004
- Full Text
- View/download PDF
24. Genetic dissection of the formation of the forebrain in Medaka, Oryzias latipes
- Author
-
Satoshi Asaka, Chritoph Winkler, Hiroshi Suwa, Chikako Morinaga, Sylke Winkler, Masakazu Osakada, Takao Sasado, Kota Saito, Thorsten Henrich, Akihito Yasuoka, Sanae Kunimatsu, Felix Loosli, Hiroshi Nishina, Rebecca Quiring, Katsutoshi Niwa, Akihiro Momoi, Harun Elmasri, Hiroki Yoda, Yukihiro Hirose, Toshiaki Katada, Norimasa Iwanami, Tomonori Deguchi, Tomomi Watanabe, Matthias Carl, Makoto Furutani-Seiki, Filippo Del Bene, Daiju Kitagawa, Clemens Grabher, Joachim Wittbrodt, and Hisato Kondoh
- Subjects
Genetics ,Mutation ,Embryology ,biology ,Mutant ,Oryzias ,medicine.disease_cause ,biology.organism_classification ,Phenotype ,Diencephalon ,Prosencephalon ,Forebrain ,medicine ,biology.protein ,Animals ,Sonic hedgehog ,Zebrafish ,Gene ,Developmental Biology - Abstract
The forebrain, consisting of the telencephalon and diencephalon, is essential for processing sensory information. To genetically dissect formation of the forebrain in vertebrates, we carried out a systematic screen for mutations affecting morphogenesis of the forebrain in Medaka. Thirty-three mutations defining 25 genes affecting the morphological development of the forebrain were grouped into two classes. Class 1 mutants commonly showing a decrease in forebrain size, were further divided into subclasses 1A to 1D. Class 1A mutation (1 gene) caused an early defect evidenced by the lack of bf1 expression, Class 1B mutations (6 genes) patterning defects revealed by the aberrant expression of regional marker genes, Class 1C mutation (1 gene) a defect in a later stage, and Class 1D (3 genes) a midline defect analogous to the zebrafish one-eyed pinhead mutation. Class 2 mutations caused morphological abnormalities in the forebrain without considerably affecting its size, Class 2A mutations (6 genes) caused abnormalities in the development of the ventricle, Class 2B mutations (2 genes) severely affected the anterior commissure, and Class 2C (6 genes) mutations resulted in a unique forebrain morphology. Many of these mutants showed the compromised sonic hedgehog expression in the zona-limitans-intrathalamica (zli), arguing for the importance of this structure as a secondary signaling center. These mutants should provide important clues to the elucidation of the molecular mechanisms underlying forebrain development, and shed new light on phylogenically conserved and divergent functions in the developmental process.
- Published
- 2004
- Full Text
- View/download PDF
25. Mutations affecting early distribution of primordial germ cells in Medaka (Oryzias latipes) embryo
- Author
-
Katsutoshi Niwa, Yasuko Kota, Yukihiro Hirose, Akihito Yasuoka, Hiroki Yoda, Tomonori Deguchi, Hiroshi Suwa, Yasuko Okamoto, Thorsten Henrich, Masakazu Osakada, Minoru Tanaka, Toshiyuki Yamanaka, Takao Sasado, Makoto Furutani-Seiki, Ai Shinomiya, Sanae Kunimatsu, Norimasa Iwanami, Chikako Morinaga, Hisato Kondoh, and Tomomi Watanabe
- Subjects
Male ,Genetics ,endocrine system ,Embryology ,biology ,urogenital system ,Oryzias ,fungi ,Cell migration ,Embryo ,In situ hybridization ,biology.organism_classification ,Phenotype ,Germ Cells ,medicine.anatomical_structure ,Mutation ,embryonic structures ,medicine ,Animals ,Female ,Ploidy ,Yolk sac ,Developmental Biology ,Genetic screen - Abstract
The development of germ cells has been intensively studied in Medaka (Oryzias latipes). We have undertaken a large-scale screen to identify mutations affecting the development of primordial germ cells (PGCs) in Medaka. Embryos derived from mutagenized founder fish were screened for an abnormal distribution or number of PGCs at embryonic stage 27 by RNA in situ hybridization for the Medaka vasa homologue (olvas). At this stage, PGCs coalesce into two bilateral vasa-expressing foci in the ventrolateral regions of the trunk after their migration and group organization. Nineteen mutations were identified from a screen corresponding to 450 mutagenized haploid genomes. Eleven of the mutations caused altered PGC distribution. Most of these alterations were associated with morphological abnormalities and could be grouped into four phenotypic classes: Class 1, PGCs dispersed into bilateral lines; Class 2, PGCs dispersed in a region more medial than that in Class 1; Class 3, PGCs scattered laterally and over the yolk sac area; and Class 4, PGCs clustered in a single median focus. Eight mutations caused a decrease in the number of PGCs. This decrease was observed in the offspring of heterozygous mothers, indicating the contribution of a maternal factor in determining PGC abundance. Taken together, these mutations should prove useful in identifying molecular mechanisms underlying the early PGC development and migration.
- Published
- 2004
- Full Text
- View/download PDF
26. Attention disorders in schizophrenia
- Author
-
Eisuke Matsushima, Katsumi Mori, Katsuya Ohta, and Hiroshi Suwa
- Subjects
Adult ,Male ,Aging ,medicine.medical_specialty ,Psychosis ,media_common.quotation_subject ,Interpersonal communication ,Neuropsychological Tests ,Audiology ,behavioral disciplines and activities ,Sustaining attention ,Discrimination, Psychological ,Schizophrenic Psychology ,Reaction Time ,medicine ,Humans ,Psychiatry ,media_common ,Psychiatric Status Rating Scales ,General Neuroscience ,Thought disorder ,Cognition ,General Medicine ,medicine.disease ,Psychiatry and Mental health ,Neurology ,Attention Deficit Disorder with Hyperactivity ,Disinhibition ,Schizophrenia ,Female ,Neurology (clinical) ,medicine.symptom ,Psychology ,Psychomotor Performance ,Antipsychotic Agents ,Vigilance (psychology) - Abstract
In order to clarify the feature of attention disorders in schizophrenia, two tasks (X and AX) of the Continuous Performance Test (CPT) were given to 36 schizophrenic patients and 25 healthy controls. The schizophrenic patients performed considerably less well than normal controls. Performances were expressed in indices such as omission and commission errors, reaction time and discriminability. Among errors, omission in both the X and AX tasks was found to be an index that varied in reaction time, indicating difficulty in sustaining attention. Omission was found to act as a state-dependent index of schizophrenia in relation to inattentiveness in clinical settings and emotional disturbance in interpersonal situations. Commission, in contrast, differed between the two tasks, acting as an index of disinhibition of reaction in the X task, and of disturbance of the capacity and allocation of attention in the AX task. Commission was also thought to be an index related to thought disorder during episodes of acute schizophrenia, that is, it reflects an essential pathology in schizophrenia.
- Published
- 2004
- Full Text
- View/download PDF
27. [Untitled]
- Author
-
Hiroshi Suwa and Kazuo Okunishi
- Subjects
Hydrology ,Atmospheric Science ,geography ,geography.geographical_feature_category ,Land use ,Alluvial fan ,Poison control ,Vegetation ,Hazard ,Debris ,Debris flow ,Natural hazard ,Earth and Planetary Sciences (miscellaneous) ,Geology ,Water Science and Technology - Abstract
A strategy is presented for the assessment ofdebris-flow hazards on alluvial fans on the basis ofa case study carried out on the southern foot of astratovolcano named Mt. Yatsugatake. Transformation ofcommercial forests into a golf course was planned ata corner of the Kikkakezawa fan. The case studyinvolves an assessment of hazards due to debris flowsof different magnitudes and their recurrenceintervals. The environmental conditions for therecurrence of these debris flows are discussed as wellas the extent of the areas affected by them. In orderto generalize the case study, concepts of hazardpotential, hazard and risk for debris flows onalluvial fans are established. Accordingly, the hazardpotential is the possible hazards at any location onan alluvial fan in an indefinitely long time period,which can be assessed on the basis of hydrological andother geoscientific investigations. Hazards associatedwith a particular land use can be evaluated on thebasis of the hazard potential considering the locationand the time period associated with the land use. Riskcan be further assessed considering the life styles inthis land and the social conditions.
- Published
- 2001
- Full Text
- View/download PDF
28. Development of Levitation Coil by Reaction Injection Molding Method
- Author
-
Tsuyoshi Fujimoto, Masao Suzuki, and Hiroshi Suwa
- Subjects
Engineering ,business.industry ,Mechanical Engineering ,Reaction injection molding ,Compression molding ,Mechanical engineering ,Molding (process) ,medicine.disease_cause ,chemistry.chemical_compound ,chemistry ,Electromagnetic coil ,Dicyclopentadiene ,Mold ,Maglev ,Levitation ,medicine ,business - Abstract
The ground coils to be used along the entire length of a Magnetically Levitated transportation (MAGLEV) system need to withstand long-term outdoor service and be provided in extremely large quantities. It is for these reasons that we require them to be durable and inexpensive. Dicyclopentadiene, a major component of low viscous liquid in Reaction Injection Molding (RIM), is injected into the mold. It reacts with catalyst and cures in a short time to produce a substance featuring superior quality not obtainable by the conventional injection molding. Besides, the molding process may be undertaken at normal temperature and pressure, the molding equipment is inexpensive, and the insulation scheme of the wound coils can be simplified. Thus, there are several reasons that the ground coils are suitable for mass production. In this paper we discuss the application of RIM technology through our trial manufacture of practical ground coils incorporated with several improvements. We investigated the economic effect as well.
- Published
- 2000
- Full Text
- View/download PDF
29. Latent structures underlying schizophrenic symptoms: a five-dimensional model
- Author
-
Hiroshi Suwa, Makoto Nakaya, and Kenichi Ohmori
- Subjects
Adult ,Male ,Psychosis ,Disease ,Severity of Illness Index ,Developmental psychology ,medicine ,Humans ,Stable phase ,Biological Psychiatry ,Psychiatric Status Rating Scales ,Negative symptom ,Positive and Negative Syndrome Scale ,Reproducibility of Results ,Dimensional modeling ,medicine.disease ,Confirmatory factor analysis ,Psychiatry and Mental health ,Schizophrenia ,Acute Disease ,Chronic Disease ,Female ,Schizophrenic Psychology ,Factor Analysis, Statistical ,Psychological Theory ,Psychology - Abstract
Latent structures of schizophrenic phenomenology were examined over the course of the illness in 100 newly-admitted patients. We compared the results of a confirmatory factor analysis (CFA) on ten competing models that had between zero and five dimensions using data assessed by the Positive and Negative Syndrome Scale (PANSS) at both the acute and chronic phases of the disease. The present findings did not support the two-dimensional construct of positive and negative symptoms in either the acute or the chronic phase of the illness. In the acute phase, a three- (positive, negative, and relational dimensions), four- (positive, negative, disorganization, and relational dimensions), and five-dimensional model (positive, negative, disorganization, excitement, and relational dimensions) fit the data relatively well. In contrast, in the chronic stable phase, only the five-dimensional model adequately fits the data. The present findings suggest that further investigation of the validity of the five-dimensional model over the course of the illness is necessary.
- Published
- 1999
- Full Text
- View/download PDF
30. Durability of Moulding Resins for Ground Coils of Maglev
- Author
-
Naoki Aihara, Tsutomu Sato, Takao Yoshikawa, and Hiroshi Suwa
- Subjects
Materials science ,Mechanical Engineering ,Bending fatigue ,Epoxy ,Durability ,Corrosion ,Flexural strength ,Maglev ,visual_art ,Mechanical strength ,Forensic engineering ,visual_art.visual_art_medium ,Composite material ,Magnetic levitation - Abstract
MAGLEV coils are moulded in resins such as epoxy and sheet moulding compounds. But the durability of resins is not yet sufficiently known well enough. Moreover, the mechanical strength of their moulding resin is degraded by the alkaline content in the concrete component of the guideway to which propulsion coils are attached. We performed bending fatigue tests using test pieces compliant pursuant to ASTM, and examined the flexural properties of test pieces immersed in an alkaline solution.
- Published
- 1999
- Full Text
- View/download PDF
31. Interlaminar Strength Properties of Multi-Layer 3D Fabric Composites
- Author
-
Kiyoshi Kemmochi, Hiroshi Suwa, and Jun Takahashi
- Subjects
Materials science ,Composite material ,Multi layer - Published
- 1999
- Full Text
- View/download PDF
32. Full length article
- Author
-
Komahashi T, Makoto Nakaya, Hiroshi Suwa, and Kenichi Ohmori
- Subjects
Middle Insomnia ,Psychosis ,Hamilton Rating Scale for Depression ,medicine.disease ,Psychiatry and Mental health ,Initial Insomnia ,Weight loss ,Schizophrenia ,mental disorders ,Insomnia ,medicine ,medicine.symptom ,Psychology ,Biological Psychiatry ,Depression (differential diagnoses) ,Clinical psychology - Abstract
The composition of the depressive syndrome was examined at both the acute and chronic phases of schizophrenic illness in 86 newly admitted patients. A subgroup with pronounced depression was defined, and a discriminant analysis was performed using symptoms from the Hamilton Rating Scale for Depression (HRSD) as discriminant variables. At the acute phase, the following nine symptoms from the HRSD were significant: depressed mood, guilt, suicide, retardation, three types of insomnia, and two somatic symptoms. At the chronic stable phase, only four symptoms were significant: depressed mood, suicide, general somatic symptoms, and loss of weight. Initial insomnia, middle insomnia, genital symptoms, and loss of insight were poorly correlated. The positive and negative symptoms and extrapyramidal side-effects were not discriminators at either phase. These findings suggest that only certain items from the HRSD may be crucial when assessing depression in schizophrenia.
- Published
- 1998
- Full Text
- View/download PDF
33. Depressive symptoms in acute schizophrenic inpatients
- Author
-
Hiroshi Suwa, Kenichi Ohmori, Tohru Komahashi, and Makoto Nakaya
- Subjects
Adult ,Hospitals, Psychiatric ,Male ,Psychosis ,medicine.medical_specialty ,Acute schizophrenia ,Significant negative correlation ,Activity factor ,Internal medicine ,mental disorders ,Schizophrenic Psychology ,medicine ,Humans ,skin and connective tissue diseases ,Biological Psychiatry ,Depression (differential diagnoses) ,Depressive symptoms ,Depressive Disorder ,Middle Aged ,medicine.disease ,Hospitalization ,Psychiatry and Mental health ,Schizophrenia ,Female ,sense organs ,Psychology ,Antipsychotic Agents ,Clinical psychology - Abstract
Prospective and longitudinal assessment of depressive, positive, and negative symptoms were performed on 86 newly admitted schizophrenic patients. The improvement of depressive symptoms was significantly correlated with the improvement in positive symptoms, but did not correlate with the improvement in negative symptoms. However, depressive symptoms were heterogeneous. Principal components analysis was used to subdivide depressive symptoms into five factors. The improvement of the depression-anxiety factor was significantly associated with improvement of positive symptoms. On the other hand, improvement of negative symptoms was significantly related to that of the reduced activity factor. The change in hypochondriasis had a significant positive correlation with the change in positive symptoms and had a significant negative correlation with the change in negative symptoms. Changes in the other factors of depressive symptoms did not appear to be associated with changes in positive or negative symptoms. The present findings suggest that the various depressive symptoms associated with acute schizophrenia may have different pathophysiological origins.
- Published
- 1997
- Full Text
- View/download PDF
34. SELECTIVE INHIBITION OF VASCULAR CELL ADHESION MOLECULE-1 EXPRESSION BY VERAPAMIL IN HUMAN VASCULAR ENDOTHELIAL CELLS1
- Author
-
Hiroshi Suwa, Masahiko Yamaguchi, Kaoru Kumada, and Masayuki Miyasaka
- Subjects
Transplantation ,medicine.medical_specialty ,Cell adhesion molecule ,Calcium channel ,Biological activity ,Adhesion ,Biology ,Cell biology ,Endothelial stem cell ,Endocrinology ,Mechanism of action ,Internal medicine ,Gene expression ,medicine ,Verapamil ,medicine.symptom ,medicine.drug - Abstract
Up-regulated expression of adhesion molecules on vascular endothelial cells (ECs) is an initial event in leukocyte adhesion to ECs, which is a crucial step in the process of inflammatory or immune reaction leading to organ transplant rejection. Verapamil and other calcium channel blockers have been
- Published
- 1997
- Full Text
- View/download PDF
35. PT634. Alleviation of neuropathic pain treated with opioid by electroconvulsive therapy
- Author
-
Hiroshi Suwa, Yukino Kobayashi, Ken Iwata, Kazutaka Ikeda, Hitoshi Mera, and Nagafumi Doi
- Subjects
Pharmacology ,Tuesday Abstracts ,business.industry ,medicine.medical_treatment ,Abstracts ,Psychiatry and Mental health ,Electroconvulsive therapy ,Opioid ,Anesthesia ,Neuropathic pain ,medicine ,Pharmacology (medical) ,business ,medicine.drug - Published
- 2016
- Full Text
- View/download PDF
36. Dysregulated expression of the IL-2 receptor β-chain abrogates development of NK cells and Thy-1+ dendritic epidermal cells in transgenic mice
- Author
-
Tetsuo Shiohara, Hiroshi Suwa, Keisuke Kuida, Fujiko Kitamura, Toshiyuki Tanaka, and Masayuki Miyasaka
- Subjects
Transgene ,Molecular Sequence Data ,Immunology ,Mice, Transgenic ,Biology ,Mice ,Aldesleukin ,Animals ,Immunology and Allergy ,IL-2 receptor ,Beta (finance) ,Mice, Inbred ICR ,Base Sequence ,T-cell receptor ,Receptors, Interleukin-2 ,Dendritic Cells ,General Medicine ,T lymphocyte ,Molecular biology ,Lymphocyte Subsets ,Cell biology ,Killer Cells, Natural ,Mice, Inbred C57BL ,Epidermal Cells ,Interleukin 12 ,Thy-1 Antigens ,Female ,CD8 - Abstract
The IL-2 receptor beta-chain (IL-2R beta), a specificity-determining subunit in the IL-2R complex with a restricted tissue distribution pattern, is essential for signal transduction. Our previous studies demonstrate that the continuous treatment of mice with anti-IL-2R beta resulted in the complete disappearance of NK cells and Thy-1+ dendritic epidermal cells (Thy-1+ dEC), suggesting that signals through IL-2R beta are critically involved in development of these lymphocyte subsets. However, these lymphocyte subsets are reported to be apparently unaffected in the IL-2-deficient mice. To further examine the biological roles of the IL-2R beta, transgenic mice carrying the IL-2R beta transgene were generated. In these mice, high levels of the cell surface expression of the IL-2R beta were observed in essentially all hematopoietic lineage cells, and CD4+ T cells as well as CD8+ T cells showed vigorous cell proliferation upon IL-2 stimulation. Surprisingly, NK cells marked with a high expression of NK1.1 in the spleen and Thy-1+ dEC in the skin were completely absent in transgenic mice. However, the development of other lymphocyte subsets including conventional alpha beta TCR+ cells, gamma delta TCR+ cells and B cells remained apparently intact. From these observations together with previous data on IL-2-deficient mice, we speculate that factors, other than IL-2 that utilizes the IL-2R beta as its functional receptor subunit, may have a vital role in the development of NK cells and Thy-1+ dEC. Implications for possible in vivo functions of over-expressed IL-2R beta are discussed.
- Published
- 1995
- Full Text
- View/download PDF
37. Preparation of CF/Ceramic Composite Using 2.5-dimensionally (Quintuple) Wove CF Cloth
- Author
-
Hiroshi Suwa, Akira Kojima, Sugio Otani, Hiroshi Ooi, and Shinsuke Hoshii
- Subjects
Hot press ,Toughness ,Materials science ,Ceramic composite ,General Materials Science ,General Chemistry ,Composite material - Published
- 1995
- Full Text
- View/download PDF
38. Reduction of N-acetylaspartate in the medial prefrontal cortex correlated with symptom severity in obsessive-compulsive disorder: meta-analyses of (1)H-MRS studies
- Author
-
Hiroshi Suwa, Yuta Aoki, and Ai Aoki
- Subjects
Obsessive-Compulsive Disorder ,MRS ,Magnetic Resonance Spectroscopy ,Thalamus ,Prefrontal Cortex ,behavioral disciplines and activities ,Severity of Illness Index ,Basal Ganglia ,Cellular and Molecular Neuroscience ,Neurochemical ,systematic review ,Functional neuroimaging ,Basal ganglia ,mental disorders ,medicine ,Humans ,Prefrontal cortex ,Biological Psychiatry ,Aspartic Acid ,cortico–striato–thalamo–cortical circuity ,medicine.disease ,Dorsolateral prefrontal cortex ,Psychiatry and Mental health ,medicine.anatomical_structure ,nervous system ,Schizophrenia ,obsessive-compulsive disorder (OCD) ,Orbitofrontal cortex ,Original Article ,Psychology ,Neuroscience ,N-acetylaspartate (NAA) - Abstract
Structural and functional neuroimaging findings suggest that disturbance of the cortico-striato-thalamo-cortical (CSTC) circuits may underlie obsessive-compulsive disorder (OCD). However, some studies with (1)H-magnetic resonance spectroscopy ((1)H-MRS) reported altered level of N-acetylaspartate (NAA), they yielded inconsistency in direction and location of abnormality within CSTC circuits. We conducted a comprehensive literature search and a meta-analysis of (1)H-MRS studies in OCD. Seventeen met the inclusion criteria for a meta-analysis. Data were separated by frontal cortex region: medial prefrontal cortex (mPFC), dorsolateral prefrontal cortex, orbitofrontal cortex, basal ganglia and thalamus. The mean and s.d. of the NAA measure were calculated for each region. A random effects model integrating 16 separate datasets with 225 OCD patients and 233 healthy comparison subjects demonstrated that OCD patients exhibit decreased NAA levels in the frontal cortex (P=0.025), but no significant changes in the basal ganglia (P=0.770) or thalamus (P=0.466). Sensitivity analysis in an anatomically specified subgroup consisting of datasets examining the mPFC demonstrated marginally significant reduction of NAA (P=0.061). Meta-regression revealed that NAA reduction in the mPFC was positively correlated with symptom severity measured by Yale-Brown Obsessive Compulsive Scale (P=0.011). The specific reduction of NAA in the mPFC and significant relationship between neurochemical alteration in the mPFC and symptom severity indicate that the mPFC is one of the brain regions that directly related to abnormal behavior in the pathophysiology of OCD. The current meta-analysis indicates that cortices and sub-cortices contribute in different ways to the etiology of OCD.
- Published
- 2012
39. Differences in the Treatment Response to Antithyroid Drugs versus Electroconvulsive Therapy in a Case of Recurrent Catatonia due to Graves' Disease
- Author
-
Kenji Takezawa, Takahiro Saito, Mitsuru Nakamura, Rie Saito, Hiroshi Suwa, and Fumiatsu Yakushiji
- Subjects
First episode ,medicine.medical_specialty ,Pediatrics ,endocrine system ,Combination therapy ,endocrine system diseases ,medicine.drug_class ,business.industry ,Catatonia ,lcsh:RC435-571 ,medicine.medical_treatment ,Graves' disease ,Case Report ,Disease ,medicine.disease ,Anxiolytic ,Psychiatry and Mental health ,Electroconvulsive therapy ,lcsh:Psychiatry ,medicine ,Thyroid function ,business ,Psychiatry - Abstract
We reported a case which presented recurrent episodes of catatonia as a result of Graves’ disease with hyperthyroidism. The patient showed different treatment response in each episodes; in the first episode, psychiatric and physical symptoms were resolved by a combination of antithyroid and anxiolytic therapies, while in the second episode, the combination therapy did not ameliorate her symptoms and ECT was indicated. We postulated that decreased CSF level of TTR and the resulting susceptibility to the derangement of peripheral thyroid function might be involved in this different treatment response.
- Published
- 2012
40. Epidemiological Survey of Dementia and Depression among the Aged Living in the Community in Japan
- Author
-
Makoto Nakaya, Jinichi Kuroda, Junko Hara, Hayato Sato, Masamori Komahashi, Teruhiko Shimizu, Shigeru Matsumura, Hiroshi Suwa, Jun Yoshikawa, Matsue Miyasaka, Tsutomu Higashimoto, Ryo Kanamori, Haruhiko Asahi, Takashi Nakano, Kenichi Ohmori, Hitoshi Fujinuma, Makoto Kosugi, and Toru Komahashi
- Subjects
Male ,Gerontology ,medicine.medical_specialty ,Dsm iii r ,Comorbidity ,Total population ,Senile dementia ,Central nervous system disease ,Age Distribution ,Sex Factors ,Japan ,Age groups ,Alzheimer Disease ,mental disorders ,Epidemiology ,Prevalence ,medicine ,Humans ,Dementia ,Sex Distribution ,Depression (differential diagnoses) ,Aged ,Psychiatric Status Rating Scales ,Depression ,business.industry ,General Neuroscience ,Age Factors ,Community Health Centers ,General Medicine ,medicine.disease ,Psychiatry and Mental health ,Neurology ,Female ,Neurology (clinical) ,business - Abstract
The authors surveyed the prevalence of depression and dementia in the elderly in Ohira town in Japan from 1989 to 1990. The total population of this town was 26,712, with 2,778 people aged 65 and above, constituting 10.4% of the total population. The prevalence of dementia (n = 128) was 6.1% and that of major depression (n = 9) was 0.4%, according to the DSM-III-R criteria. The prevalence of a depressive state which did not fulfill the criteria for major depression (n = 55) was 2.4%. The patients with multi-infarct dementia (n = 49) suffered from depression (42.8%) more frequently than those with dementia of the Alzheimer type (11.1%). The rate of depression coexisting with dementia increased with aging, while the rate of depression without dementia did not change in all the age groups.
- Published
- 1994
- Full Text
- View/download PDF
41. Selective long-term elimination of natural killer cells in vivo by an anti-interleukin 2 receptor beta chain monoclonal antibody in mice
- Author
-
Keisuke Kuida, Fujiko Kitamura, Masayuki Miyasaka, Hiroshi Suwa, Toshiyuki Tanaka, and Y Nagasaka
- Subjects
Male ,Time Factors ,T cell ,Immunology ,Biology ,Lymphocyte Depletion ,CD49b ,Natural killer cell ,Mice ,Interleukin 21 ,medicine ,Animals ,Immunology and Allergy ,Cytotoxic T cell ,Mice, Inbred C3H ,Lymphokine-activated killer cell ,Janus kinase 3 ,Antibodies, Monoclonal ,Receptors, Interleukin-2 ,Articles ,Molecular biology ,Lymphocyte Subsets ,Killer Cells, Natural ,Mice, Inbred C57BL ,medicine.anatomical_structure ,Interleukin 12 ,Female - Abstract
The interleukin 2 receptor beta chain (IL-2R beta) is preferentially expressed in natural killer (NK) cells, but is not detected in a majority of resting T and B cells. We recently established a novel monoclonal antibody (mAb) to murine IL-2R beta and examined in vivo the effect of the mAb in mice. We found that intraperitoneal injection of the anti-IL-2R beta mAb into adult mice resulted in a selective in vivo elimination of splenic NK function in various mouse strains. The reduction of NK cell function is associated with complete disappearance of NK1.1+ cells in C57BL/6 mice. Other lymphocyte subsets in the thymus and spleen were uncompromised. T cell function was not affected by the mAb treatment as judged by allogeneic cytotoxic T cell induction. The single injection of anti-IL-2R beta mAb caused a long-term elimination of splenic NK cells, lasting for at least 5 wk. We also found that NK and/or NK precursor cells become susceptible to the mAb treatment only after birth, suggesting that functional maturation of NK cells in terms of IL-2R beta expression is a later event in the course of NK cell development. The use of the anti-IL-2R beta mAb will be useful in defining the physiological role of NK cells in host defense as well as dissecting their developmental pathway in vivo.
- Published
- 1993
- Full Text
- View/download PDF
42. Urinary Changes after Proctocolectomy and Correction of these Changes with a Citrat Emixture
- Author
-
Katsumi Go, Ishiguro N, Katsuhiko Arai, Yasunobu Yamazaki, Hiroshi Suwa, Kazutaka Koganei, Tsuneo Fukushima, Akira Sugita, and Hirofumi Harada
- Subjects
medicine.medical_specialty ,Proctocolectomy ,business.industry ,Urinary system ,medicine.medical_treatment ,Gastroenterology ,Urology ,medicine ,Surgery ,business - Abstract
大腸全摘後は大腸の水分, 電解質吸収機能の喪失により体内の水分, 電解質が欠乏し, その結果, 尿量の減少, 尿pHの低下を来してくる.今回, 潰瘍性大腸炎, 大腸ポリポーシスに対して大腸全摘, J型回腸嚢肛門吻合術 (IAA) 20例, 回腸人工肛門造設 (ILE) 8例に, 尿分析を行った.尿量, 尿中Na濃度, 尿中pHはIAA, ILEともに対照群にくらべて有意に低下したが, 尿中尿酸濃度は有意に高値を示した.これらの患者に対し尿アルカリ化剤であるクエン酸ナトリウムカリウム合剤を毎食後服用 (3g/day) させると, IAA, ILEともに尿中Na濃度, 尿pHは上昇し, 尿酸濃度は有意に低下した.大腸全摘後症例で, 尿中電解質濃度および尿pHに異常がある場合には尿アルカリ化剤を投与して正常化し, かつ結石合併を予防することが可能であると考えられた.
- Published
- 1992
- Full Text
- View/download PDF
43. Weaving Ability of Pitch-based Carbon Fiber and It's Evaluation Method
- Author
-
Yasuto Soutome, Hiroshi Suwa, Sugio Otani, and Kazuo Kojima
- Subjects
Materials science ,Evaluation methods ,Composite material ,Weaving - Published
- 1992
- Full Text
- View/download PDF
44. [Neoadjuvant and adjuvant chemotherapy with methotrexate, cisplatin and bleomycin for advanced penile cancer: a case report]
- Author
-
Yasushi, Yumura, Kazunori, Takase, Hiroshi, Suwa, Junichi, Ohta, Tei-ichiro, Ueki, Masaki, Kawai, Atsushi, Fujikawa, Yumiko, Yokomizo, and Masatoshi, Moriyama
- Subjects
Male ,Urologic Surgical Procedures, Male ,Middle Aged ,Disease-Free Survival ,Neoadjuvant Therapy ,Bleomycin ,Methotrexate ,Treatment Outcome ,Chemotherapy, Adjuvant ,Lymphatic Metastasis ,Antineoplastic Combined Chemotherapy Protocols ,Carcinoma, Squamous Cell ,Humans ,Lymph Node Excision ,Cisplatin ,Penile Neoplasms ,Neoplasm Staging ,Penis - Abstract
A 58-year-old male consulted our hospital because of penile swelling and pain with bilateral inguinal lymphadenopathy. Pathological examination of the penile tumor and right superficial inguinal lymph node biopsy demonstrated moderately differentiated squamous cell carcinoma with lymph node metastasis. We diagnosed the tumor inoperable radically and adjuvant chemotherapy with methotrexate, cisplatin and bleomycin was administered, followed by partial penectomy and left superficial lymphadenectomy. The surgical specimens showed few viable tumor cells. This combination chemotherapy is suggested to be effective for the treatment of advanced penile cancer.
- Published
- 2007
45. [Electroconvulsive therapy for neurological disorders]
- Author
-
Nagafumi, Doi, Tatsuo, Sameshima, Hiroshi, Suwa, Hitoshi, Mera, Takehiko, Nagao, Masayuki, Yokochi, Mitsuru, Nakamura, and Kunihiro, Isse
- Subjects
Humans ,Female ,Parkinson Disease ,Nervous System Diseases ,Electroconvulsive Therapy ,Aged ,Pain, Intractable - Abstract
Electroconvulsive therapy (ECT) recovers the brain function through generalized convulsion induced by electrical stimulation of the brain. While the primary targets of ECT are psychiatric disorders such as depression, schizophrenia, and schizoaffective disorder, it has been well documented that ECT has therapeutic effects on muscular rigidity of Parkinson's disease and neuroleptics-induced malignant syndrome. Recently we demonstrated that ECT reduces intractable pain and allodynia associated with deafferentation pain disorders by recovering the function of the thalamic nucleus. ECT, if applied on appropriate clinical assessments, may contribute to the therapeutics of neuropsychiatric disorders.
- Published
- 2007
46. volcanic hazards at Mount Semeru, East Java (Indonesia), with emphasis on lahars
- Author
-
Surono, Bambang Sukatja, Jean-Claude Thouret, Franck Lavigne, Hiroshi Suwa, Laboratoire Magmas et Volcans (LMV), Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Jean Monnet [Saint-Étienne] (UJM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de géographie physique : Environnements Quaternaires et Actuels (LGP), Université Paris 1 Panthéon-Sorbonne (UP1)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet [Saint-Étienne] (UJM)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), and Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Volcanic hazards ,geography ,geography.geographical_feature_category ,010504 meteorology & atmospheric sciences ,Lava ,Lahar ,Volcanic hazards . Mount Semeru . Java (Indonesia) . Composite cone . Eruptive activity . Lahar . Sediment yield ,Pyroclastic rock ,[SDU.STU]Sciences of the Universe [physics]/Earth Sciences ,010502 geochemistry & geophysics ,01 natural sciences ,Volcano ,13. Climate action ,Geochemistry and Petrology ,Phreatomagmatic eruption ,[SDU.STU.VO]Sciences of the Universe [physics]/Earth Sciences/Volcanology ,Stratovolcano ,Tephra ,Geomorphology ,Geology ,0105 earth and related environmental sciences - Abstract
International audience; Mt. Semeru, the highest mountain in Java (3,676 m), is one of the few persistently active composite volcanoes on Earth, with a plain supporting about 1 million people. We present the geology of the edifice, review its historical eruptive activity, and assess hazards posed by the current activity, highlighting the lahar threat. The composite andesite cone of Semeru results from the growth of two edifices: the Mahameru ‘old' Semeru and the Seloko ‘young' Semeru. On the SE flank of the summit cone, a N130-trending scar, branched on the active Jonggring- Seloko vent, is the current pathway for rockslides and pyroclastic flows produced by dome growth. The eruptive activity, recorded since 1818, shows three styles: (1) The persistent vulcanian and phreatomagmatic regime consists of short-lived eruption columns several times a day; (2) increase in activity every 5 to 7 years produces several kilometer-high eruption columns, ballistic bombs and thick tephra fall around the vent, and ash fall 40 km downwind. Dome extrusion in the vent and subsequent collapses produce block-and-ash flows that travel toward the SE as far as 11 km from the summit; and (3) flank lava flows erupted on the lower SE and E flanks in 1895 and in 1941– 1942. Pyroclastic flows recur every 5 years on average while large-scale lahars exceeding 5 million m3 each have occurred at least five times since 1884. Lumajang, a city home to 85,000 people located 35 km E of the summit, was devastated by lahars in 1909. In 2000, the catchment of the Curah Lengkong River on the ESE flank shows an annual sediment yield of 2.7×105 m3 km−2 and a denudation rate of 4 105 t km−2 yr−1, comparable with values reported at other active composite cones in wet environment. Unlike catchments affected by high magnitude eruptions, sediment yield at Mt. Semeru, however, does not decline drastically within the first post-eruption years. This is due to the daily supply of pyroclastic debris shed over the summit cone, which is remobilised by runoff during the rainy season. Three hazard-prone areas are delineated at Mt. Semeru: (1) a triangle-shaped area open toward the SE has been frequently swept by dome-collapse avalanches and pyroclastic flows; (2) the S and SE valleys convey tens of rain-triggered lahars each year within a distance of 20 km toward the ring plain; (3) valleys 25 km S, SE, and the ring plain 35 km E toward Lumajang can be affected by debris avalanches and debris flows if the steep-sided summit cone fails.
- Published
- 2007
- Full Text
- View/download PDF
47. [Life-long education of a specialists is possible only through daily activities as clinical instructors being evaluated by interns and mutual efforts for advancement]
- Author
-
Kunihiro, Ichinose, Mitsuru, Nakamura, Kenji, Takezawa, Ichiro, Masutomi, Yoichi, Shima, Yoko, Hirayama, Kahoko, Sorimachi, Teruhiko, Shimizu, Hiroyo, Ishikawa, Namiko, Kaji, Sayaka, Nakajima, Michiko, Wataru, Shiho, Nishigaki, Hiroshi, Suwa, Yosuke, Toyama, Masaki, Okumura, Yoshikazu, Ishitsuka, Ken, Shimizu, Kazuya, Kokubo, Kenji, Sasaki, and Shodai, Saito
- Subjects
Psychiatry ,Japan ,Internship and Residency ,Education, Medical, Continuing ,Interpersonal Relations - Published
- 2006
48. Central connection of the optic, oculomotor, trochlear and abducens nerves in medaka, Oryzias latipes
- Author
-
Hiroshi Suwa, Tomonori Deguchi, Naoyuki Yamamoto, Masami Yoshimoto, and Hisato Kondoh
- Subjects
Nervous system ,Motor Neurons ,Afferent Pathways ,Lysine ,Histological Techniques ,Oryzias ,Optic Nerve ,Trochlear Nerve ,Anatomy ,Biology ,Reticular formation ,medicine.anatomical_structure ,Posterior commissure ,nervous system ,Abducens nucleus ,Trochlear nucleus ,Abducens Nerve ,Oculomotor Nerve ,medicine ,Optic nerve ,Terminal nerve ,Animals ,Animal Science and Zoology ,Nucleus ,Vision, Ocular - Abstract
Medaka (Oryzias latipes) is one of the few vertebrate experimental animals in which inbred lines have been established. It is also a species that has advanced in genetic studies in a manner comparable to zebrafish. This fish is therefore a good model for studying functional organization of the nervous system, but anatomical analysis of its nervous system has been limited to embryonic stages. In the present study, we investigated anatomy of cranial nerves in adult fish focusing on the visual function, using an inbred strain of medaka. Cranial nerves of medaka were labeled using biocytin, revealing a central distribution of retinofugal terminals, retinopetal neurons, and oculomotor, trochlear and abducens motor neurons. The optic nerve of the adult medaka was of a complete decussation type. Retinofugal terminals were located in 8 brain nuclei, the suprachiasmatic nucleus, nucleus pretectalis superficialis, nucleus dorsolateralis thalami, area pretectalis pars dorsalis (APd), area pretectalis pars ventralis (APv), nucleus of the posterior commissure (NPC), accessory optic nucleus, and the tectum opticum. Retinopetal neurons were identified in 6 brain nuclei, the ganglion of the terminal nerve, preoptic retinopetal nucleus, nucleus dorsolateralis thalami, APd, APv, and NPC. The oculomotor neurons were mostly labeled ipsilaterally and were located dorsomedially, abutting the fasciculus longitudinalis medialis in the mesencephalon. The trochlear nucleus was located contralaterally and dorsolaterally adjacent to the fasciculus longitudinalis medialis in the mesencephalon. The abducens nucleus was located ipsilaterally in a ventrolateral part of the rhombencephalic reticular formation. These results, generally similar to those in other teleosts, provide the basis for future behavioral and genetic studies in medaka.
- Published
- 2005
49. Mutations affecting somite formation in the Medaka (Oryzias latipes)
- Author
-
Tomonori Deguchi, Masakazu Osakada, Takao Sasado, Rebecca Quiring, Yukihiro Hirose, Katsuhito Takahashi, Akihito Yasuoka, Christoph Winkler, Felix Loosli, Clemens Grabher, Hiroshi Nishina, Norihisa Iwanami, Katsutoshi Niwa, Tomomi Watanabe, Matthias Carl, Keiko Abe, Hiroshi Suwa, Hiroki Yoda, Chikako Morinaga, Harun Elmasri, Sanae Kunimatsu, Daniel Liedtke, Sylke Winkler, Yousuke Takahama, Filippo Del Bene, Thorsten Henrich, Toshiaki Katada, Makoto Furutani-Seiki, Hisato Kondoh, and Joachim Wittbrodt
- Subjects
Genetics ,Embryology ,Mutation ,Oryzias ,fungi ,Mutant ,Mutagenesis (molecular biology technique) ,Biology ,medicine.disease_cause ,biology.organism_classification ,Somite ,medicine.anatomical_structure ,Somites ,Somitogenesis ,medicine ,Paraxial mesoderm ,Animals ,Zebrafish ,Developmental Biology ,Body Patterning - Abstract
The metameric structure of the vertebrate trunk is generated by repeated formation of somites from the unsegmented presomitic mesoderm (PSM). We report the initial characterization of nine different mutants affecting segmentation that were isolated in a large-scale mutagenesis screen in Medaka (Oryzias latipes). Four mutants were identified that show a complete or partial absence of somites or somite boundaries. In addition, five mutations were found that cause fused somites or somites with irregular sizes and shapes. In situ hybridization analysis using specific markers involved in the segmentation clock and antero-posterior (A-P) polarity of somites revealed that the nine mutants can be compiled into two groups. In group 1, mutants exhibit defects in tailbud formation and PSM prepatterning, whereas A-P identity in the somites is defective in group 2 mutants. Three mutants (planlos, pll; schnelles ende, sne; samidare, sam) have characteristic phenotypes that are similar to those in zebrafish mutants affected in the Delta/Notch signaling pathway. The majority of mutants, however, exhibit somitic phenotypes distinct from those found in zebrafish, such as individually fused somites and irregular somite sizes. Thus, these Medaka mutants can be expected to provide clues to uncovering novel components essential for somitogenesis.
- Published
- 2004
50. Contrasts between Debris Flows, Hyperconcentrated Flows and Stream Flows at a Channel of Mount Semeru, East Java, Indonesia
- Author
-
Franck Lavigne, Hiroshi Suwa, Laboratoire de géographie physique : Environnements Quaternaires et Actuels (LGP), and Université Paris 1 Panthéon-Sorbonne (UP1)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Hydrology ,010504 meteorology & atmospheric sciences ,Lahar ,Fluvial ,010502 geochemistry & geophysics ,01 natural sciences ,Debris ,Debris flow ,[SHS]Humanities and Social Sciences ,13. Climate action ,Hyperconcentrated flow ,Mudflow ,[SDE]Environmental Sciences ,Erosion ,Geomorphology ,Sediment transport ,Geology ,0105 earth and related environmental sciences ,Earth-Surface Processes - Abstract
In order to differentiate between different types of sediment-laden-flows in volcanic channels, we carried out observation of debris flows, hyperconcentrated flows, and stream flows in the Curah Lengkong river on the southeast slope of Mount Semeru in East Java, Indonesia. The aims of this study are: (1) to provide quantitative data for these flows in motion; (2) to compare the data for different types of flow that occur in the same river; (3) to assess the influence of rainfall on debris flows, hyperconcentrated flows, and streamflow generation. The Curah Lengkong river transports large volumes of sediment, in the range of 1×10 5 to 5×10 5 m 3 per debris flow, and 10 3 to 10 5 m 3 per hyperconcentrated flow and stream flow. Large sediment discharges result from the following factors: continuous and voluminous sediment supply of fine juvenile material by daily explosions of the Semeru volcano, pyroclastic source material emplaced on steep slopes, strong erosion of weathered river banks, and strong rainfall intensities. The occurrence of the flows focuses in the period from November through April, and the daily timing of it is the mid to late afternoon. Nearly all debris flows are triggered by stationary rainfall confined to the upper slopes of Mount Semeru, whereas hyperconcentrated flows and stream flows are mainly generated by migratory or regional rains driven upwards on the eastern slope. This slope receives its maximum of annual rainfall (3800 mm) at 800 m asl. The peak surface velocity of debris flows is always greater than the peak frontal velocity. The peak discharge of debris flows occurs several minutes after the passage of the flow front. Volumetric concentrations of sediment are high (48% to 69%) between the debris flow front and the point of peak discharge; after the peak discharge it usually decreases gradually. Contrary to the case of debris flows, high concentration of sediment appears in various portion of hyperconcentrated flows and stream flows: near the front, in the mid point or at the back of flows, although the concentration of sediments in them is much less than in of debris flows. Relationships between sediment discharge, total volume and peak discharge show a very strong positive correlation for debris flows and hyperconcentrated flows. Therefore, sediment discharge can be roughly estimated from direct visual observation.
- Published
- 2004
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.