24 results on '"Iwanami M"'
Search Results
2. A simplified approach to estimate seismic fragility of corrosion damaged RC bridge piers
- Author
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Biswas, RK, Iwanami, M, Chijiwa, N, Saito, T, and Malaga-Chuquitaype, C
- Abstract
Safety of the existing corrosion damaged reinforced concrete (RC) bridges during a seismic event is a matter of increasing concern. To reduce the enormous economic loss and casualties, it is important to examine the potential seismic risk of corroded RC bridge structures. This paper presents a simplified method to determine the seismic fragility of corroded RC bridge piers by developing a simplified FEM model and seismic fragility analysis. To make the proposed approach realistic, the numerical model is validated with two different experimental studies available in the literature. Obtain results from the simplified numerical model demonstrated excellent agreement with the experimental tests, making it suitable for seismic vulnerability analysis. After validation, the numerical model is further adopted to perform non-linear static pushover analysis of corroded RC bridge piers. Finally, a recently developed software tool SPO2FRAG is utilized to carry out seismic fragility analysis by defining three different damage levels.
- Published
- 2022
3. Experimental study and numerical analysis on the axial compression performance of CFRP strip reinforced round-end aluminum alloy tube concrete column
- Author
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Chuantao Cheng, Congrong Tang, Xin Xiong, Qirong Qiu, Pengcheng Liao, and Iwanami Motoi
- Subjects
Physics ,QC1-999 - Abstract
Round-end aluminum alloy tube concrete columns had good durability and were very economical, but the low strength and elastic modulus of aluminum alloy led to the need for improvement in performance. This paper proposes carbon fiber reinforced plastic (CFRP) strip reinforced round-end aluminum alloy tube concrete (CREAC) columns and investigates their mechanical properties under axial compression loads. A total of eight specimens were tested, including seven CFRP reinforced specimens and one control specimen. The effects of the width, spacing, and number of layers of CFRP strips on the axial compression performance of CREAC under the same amount of CFRP were studied. The experimental results indicate that the main failure modes of the specimen are the buckling of round-end aluminum alloy tubes and the fracture of CFRP strips. The CFRP strip can significantly improve the ultimate bearing capacity of the specimen, with a maximum increase of 15.3% in the test range. When the amount of CFRP is the same, as the number of CFRP strips decreases, the bearing capacity and ductility deteriorate. Increasing the width and thickness of CFRP strips significantly improves ductility. On the basis of the validated finite element model, parameter analysis was conducted, and the calculation method for stability coefficients was fitted. A calculation method for axial compression bearing capacity suitable for CREAC was proposed, with a maximum error of less than 1% between the predicted results and experimental results.
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- 2024
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4. Stability of tunnel face in unsaturated sand possessing apparent cohesion: A micro-macro analytical approach
- Author
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Junzuo He, Shaoming Liao, Mengbo Liu, Iwanami Motoi, and Junhua Xiao
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Tunnel face stability ,Arching effect ,Unsaturated sand ,Apparent cohesion ,Limit equilibrium analysis ,Engineering geology. Rock mechanics. Soil mechanics. Underground construction ,TA703-712 - Abstract
Although the stability of tunnel face in the dry and saturated sandy ground is widely studied, the unsaturated sandy ground which possesses apparent cohesion is more common in engineering. For remedying this deficiency, the theoretical association between apparent cohesion and the saturation degree is firstly established in microscopic prospective. Then, the formation mechanism of the self-stabilized arch and the limit support pressure (LSP) of the tunnel face are derived by incorporating apparent cohesion into the macroscopic limit equilibrium analysis of the multi-arches model. Subsequently, the validities of the proposed approach in estimating apparent cohesion, loosening zone height and LSP are well confirmed (the average error rates of LSP are within 12 %) via comparisons with direct shear tests, model tests and other existing methods. Finally, as revealed by the parametric discussion, under the effect of apparent cohesion, LSP is negatively correlated with compactness, internal friction angle, and contact angle while decreases firstly (to a minimum value of 0.09γD ∼ 0.15γD) and then increase with the rise of saturation degree. Besides, the LSP has a parabolic distribution along the depth with its peak value emerges between 0.3D and 0.45D.
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- 2023
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5. APPLICATION OF DETERIORATION MONITORING SYSTEM TO CONCRETE SUPERSTRUCTURE OF OPEN-TYPE WHARF
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KATO, E., KAWABATA, Y., IWANAMI, M., KATO, E., KAWABATA, Y., and IWANAMI, M.
- Abstract
The Thirteenth East Asia-Pacific Conference on Structural Engineering and Construction (EASEC-13), September 11-13, 2013, Sapporo, Japan.
- Published
- 2013
6. Electrical Characteristics of Printed Circuit Boards constructed with two ground planes and a coil-shaped conductor
- Author
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Iwanami, M., primary, Hoshino, S., additional, Kuriyama, T., additional, and Tohya, H., additional
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- 2000
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7. The Synthesis of Pyridoxine Derivatives
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Iwanami M, Murakami Masuo, and Osawa I
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Chemistry ,Stereochemistry ,Disulfide bond ,medicine ,General Medicine ,Pyridoxine ,medicine.drug - Published
- 1968
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8. Seasonal variations in serum inorganic phosphate and calcium with special reference to parathyroid activity
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Iwanami, M., Osiba, S., Yamada, T., and Yoshimura, H.
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- 1959
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9. Shear Fatigue Load Carrying Mechanism of Reinforced Concrete Beams with Corrosion Cracks along Longitudinal Rebars
- Author
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Yamada, Y., Nobuhiro CHIJIWA, and Iwanami, M.
10. Feeding Experiment of Japanese Shorthorn Steers with Pelleted Ligneous Materials
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Asada, T., primary, Tokita, N., additional, Konno, T., additional, Koga, M., additional, Iwanami, M., additional, Iwamoto, S., additional, and Kaikawa, Z., additional
- Published
- 1989
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11. Probable rapid eye movement sleep behavior disorder, nocturnal disturbances and quality of life in patients with Parkinson’s disease: a case-controlled study using the rapid eye movement sleep behavior disorder screening questionnaire
- Author
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Suzuki Keisuke, Miyamoto Tomoyuki, Miyamoto Masayuki, Watanabe Yuka, Suzuki Shiho, Tatsumoto Muneto, Iwanami Masaoki, Sada Tsubasa, Kadowaki Taro, Numao Ayaka, Hashimoto Kenichi, Sakuta Hideki, and Hirata Koichi
- Subjects
Parkinson’s disease ,Rapid eye movement sleep behavior disorder ,Cognition ,Quality of life ,Nocturnal problems ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Abstract Background Increasing evidence provides a clear association between rapid eye movement sleep behavior disorders (RBD) and Parkinson’s disease (PD), but the clinical features that determine the co-morbidity of RBD and PD are not yet fully understood. Methods We evaluated the characteristics of nocturnal disturbances and other motor and non-motor features related to RBD in patients with PD and the impact of RBD on their quality of life. Probable RBD (pRBD) was evaluated using the Japanese version of the RBD screening questionnaire (RBDSQ-J). Results A significantly higher frequency of pRBD was observed in PD patients than in the controls (RBDSQ-J ≥ 5 or ≥ 6: 29.0% vs. 8.6%; 17.2% vs. 2.2%, respectively). After excluding restless legs syndrome and snorers in the PD patients, the pRBD group (RBDSQ-J≥5) showed higher scores compared with the non-pRBD group on the Parkinson’s disease sleep scale-2 (PDSS-2) total and three-domain scores. Early morning dystonia was more frequent in the pRBD group. The Parkinson’s Disease Questionnaire (PDQ-39) domain scores for cognition and emotional well-being were higher in the patients with pRBD than in the patients without pRBD. There were no differences between these two groups with respect to the clinical subtype, disease severity or motor function. When using a cut-off of RBDSQ-J = 6, a similar trend was observed for the PDSS-2 and PDQ-39 scores. Patients with PD and pRBD had frequent sleep onset insomnia, distressing dreams and hallucinations. The stepwise linear regression analysis showed that the PDSS-2 domain “motor symptoms at night”, particularly the PDSS sub-item 6 “distressing dreams”, was the only predictor of RBDSQ-J in PD. Conclusion Our results indicate a significant impact of RBD co-morbidity on night-time disturbances and quality of life in PD, particularly on cognition and emotional well-being. RBDSQ may be a useful tool for not only screening RBD in PD patients but also predicting diffuse and complex clinical PD phenotypes associated with RBD, cognitive impairment and hallucinations.
- Published
- 2013
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12. Integrated approach for seismic wave prediction and structural evaluation of Oya tuff quarry underground spaces: Field observations and numerical modeling.
- Author
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Cheng C, Shizuo N, Dintwe TKM, Seiki T, and Iwanami M
- Abstract
This study evaluates the structural stability of large underground spaces in seismic conditions, represented by the Oya underground stone mining plant. By directly monitoring the seismic response of the underground mining site, significant earthquake activities at the plate boundaries of the Tokyo region and Ibaraki Prefecture offshore area were observed. Additionally, through an in-depth analysis of seismic records from different locations within the underground structure, the dynamic characteristics and motion patterns of the Oya underground stone mining plant were revealed, revealing its movement trajectory during earthquakes. Additionally, this study innovatively applied seismic waves measured at the original site as input parameters and artificially generated seismic waves based on their response spectra. A numerical analysis was performed after ensuring the model's high correlation with the original site was met. The findings demonstrate that the results of both parameter input methods are confirmable and valuable. Under severe seismic conditions, instability was observed in some regions of the underground mining site. The study also discusses the location and damage mechanisms of the mining site's structure under seismic effects, providing valuable insights for the safety assessment of similar large underground spaces and proposing new approaches for selecting input parameters in seismic analysis., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: CHENG CHUANTAO reports financial support was provided by 10.13039/501100002241Japan Science and Technology Agency. Takafumi SEIKI reports financial support was provided by Chuden Engineering Consultants Co. Ltd, Japan. Takafumi SEIKI reports financial support was provided by Utsunomiya City Hall for Oya area development. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)
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- 2024
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13. Evaluation of photoreceptor-directed fibroblasts derived from retinitis pigmentosa patients with defects in the EYS gene: a possible cost-effective cellular model for mechanism-oriented drug.
- Author
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Rai D, Iwanami M, Takahashi Y, Komuta Y, Aoi N, Umezawa A, and Seko Y
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- Cost-Benefit Analysis, DNA Mutational Analysis, Eye Proteins metabolism, Fibroblasts metabolism, Humans, Mutation, Pedigree, Rhodopsin genetics, Phosphatidylinositol 3-Kinases genetics, Retinitis Pigmentosa genetics, Retinitis Pigmentosa pathology
- Abstract
Background: The most common gene responsible for autosomal recessive retinitis pigmentosa (RP) is EYS. The manner of decay of genetically defective EYS gene transcripts varies depending on the type of mutation using our cellular model, which consists of induced photoreceptor-directed fibroblasts from EYS-RP patients (EYS-RP cells). However, disease-specific profiles have not been clarified in EYS-RP cells. Herein we investigated comprehensive gene expression patterns and restoration of altered expression by low molecular weight molecules in EYS-RP cells., Methods: Using induced photoreceptor-like cells by CRX, RAX, NeuroD, and OTX2, we employed qRT-PCR and DNA microarray analysis to compare expression levels of disease-related genes in EYS-RP cells. We investigated the effect of antiapoptotic or anti-endoplasmic reticulum (ER) stress/antioxidant reagents on the restoration of altered gene expression., Results: Expression levels of phototransduction-related genes (blue opsin, rhodopsin, S-antigen, GNAT1, GNAT2) were lower in EYS-RP cells. CRYGD was extracted by global gene expression analysis, as a downregulated, retina-related and apoptosis-, endoplasmic reticulum (ER) stress- or aging-related gene. Pathway enrichment analysis suggested that "complement and coagulation cascades," "ECM-receptor interaction" and "PI3K-Akt signaling pathway" could be involved in EYS-RP-associated pathogenesis. Among the matching/overlapping genes involved in those pathways, F2R was suggested as an EYS-RP-associated gene. The downregulation of CRYGD and F2R was completely restored by additional 4-PBA, an inhibitor of ER stress, and partially restored by metformin or NAC. In addition, 4-PBA normalized the expression level of cleaved caspase-3., Conclusions: Our cellular model may reflect the ER stress-mediated degenerative retina and serve as a pathogenesis-oriented cost-effective rescue strategy for RP patients., (© 2022. The Author(s).)
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- 2022
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14. Gradiometer Using Separated Diamond Quantum Magnetometers.
- Author
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Masuyama Y, Suzuki K, Hekizono A, Iwanami M, Hatano M, Iwasaki T, and Ohshima T
- Abstract
The negatively charged nitrogen-vacancy (NV) center in diamonds is known as the spin defect and using its electron spin, magnetometry can be realized even at room temperature with extremely high sensitivity as well as a high dynamic range. However, a magnetically shielded enclosure is usually required to sense weak magnetic fields because environmental magnetic field noises can disturb high sensitivity measurements. Here, we fabricated a gradiometer with variable sensor length that works at room temperature using a pair of diamond samples containing negatively charged NV centers. Each diamond is attached to an optical fiber to enable free sensor placement. Without any magnetically shielding, our gradiometer realizes a magnetic noise spectrum comparable to that of a three-layer magnetically shielded enclosure, reducing the noises at the low-frequency range below 1 Hz as well as at the frequency of 50 Hz (power line frequency) and its harmonics. These results indicate the potential of highly sensitive magnetic sensing by the gradiometer using the NV center for applications in noisy environments such as outdoor and in vehicles.
- Published
- 2021
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15. Five major sequence variants and copy number variants in the EYS gene account for one-third of Japanese patients with autosomal recessive and simplex retinitis pigmentosa.
- Author
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Iwanami M, Oishi A, Ogino K, Seko Y, Nishida-Shimizu T, Yoshimura N, and Kato S
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- Chromosome Segregation genetics, Female, Heterozygote, Humans, Japan, Male, Pedigree, Asian People genetics, DNA Copy Number Variations genetics, Eye Proteins genetics, Genes, Recessive, Genetic Predisposition to Disease, Mutation genetics, Retinitis Pigmentosa genetics
- Abstract
Purpose: To elucidate the variant spectrum of the EYS gene in a large cohort of Japanese patients with autosomal recessive and simplex retinitis pigmentosa (arRP and sRP)., Methods: We performed a direct sequencing analysis of 44 exons of the EYS gene in 469 patients with RP (including 144 arRP, 288 sRP, and 17 autosomal dominant RP (adRP) cases) in eastern and western regions of Japan and a multiplex ligation-dependent probe amplification (MLPA) of patients who had a single heterozygous pathogenic variant., Results: We identified six pathogenic and 16 likely pathogenic variants from a total of 186 nucleotide sequence variants, of which five variants, c.2528G>A (p.(Gly843Glu)), c.4957dupA (p.(Ser1653Lysfs*2)), c.6557G>A (p.(Gly2186Glu)), c.6563T>C (p.(Ile2188Thr)), and c.8868C>A (p.(Tyr2956*)), were prevalent in patients with arRP and sRP. The homozygous and heterozygous combinations of these five variants accounted for 32.4% (140/432) of Japanese patients with arRP and sRP. Five patients with adRP also had these variants. These five variants segregated with the phenotype in 15 families with RP. MLPA revealed seven copy number variations (CNVs) of the EYS exon(s)., Conclusions: This study showed that five major sequence variants and CNVs in the EYS gene account for one-third of Japanese patients with arRP and sRP, and these variants are also responsible for RP showing an autosomal dominant inheritance pattern. This is the first report showing the pathogenicity of three missense variants (p.(Gly843Glu), p.(Gly2186Glu), and p.(Ile2188Thr)) and the presence of CNVs in the EYS gene of Japanese patients with arRP and sRP., (Copyright © 2019 Molecular Vision.)
- Published
- 2019
16. The manner of decay of genetically defective EYS gene transcripts in photoreceptor-directed fibroblasts derived from retinitis pigmentosa patients depends on the type of mutation.
- Author
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Seko Y, Iwanami M, Miyamoto-Matsui K, Takita S, Aoi N, Umezawa A, and Kato S
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- Aged, Arrestin genetics, Arrestin metabolism, Basic Helix-Loop-Helix Transcription Factors genetics, Basic Helix-Loop-Helix Transcription Factors metabolism, Case-Control Studies, Cell Differentiation, Cyclic Nucleotide Phosphodiesterases, Type 6 genetics, Cyclic Nucleotide Phosphodiesterases, Type 6 metabolism, Eye Proteins metabolism, Female, Fibroblasts pathology, Gene Expression Regulation, Heterozygote, Homeodomain Proteins genetics, Homeodomain Proteins metabolism, Homozygote, Humans, Male, Middle Aged, Nerve Tissue Proteins genetics, Nerve Tissue Proteins metabolism, Otx Transcription Factors genetics, Otx Transcription Factors metabolism, Photoreceptor Cells, Vertebrate pathology, Recoverin genetics, Recoverin metabolism, Retinitis Pigmentosa metabolism, Retinitis Pigmentosa pathology, Rhodopsin genetics, Rhodopsin metabolism, Rod Opsins genetics, Rod Opsins metabolism, Trans-Activators genetics, Trans-Activators metabolism, Transcription Factors genetics, Transcription Factors metabolism, Eye Proteins genetics, Fibroblasts metabolism, Mutation, Photoreceptor Cells, Vertebrate metabolism, RNA Stability, RNA, Messenger genetics, Retinitis Pigmentosa genetics
- Abstract
Background: Generation of induced photoreceptors holds promise for in vitro modeling of intractable retinal diseases. Retinitis pigmentosa is an inherited retinal dystrophy that leads to visual impairment. The EYS gene was reported to be the most common gene responsible for autosomal recessive retinitis pigmentosa (arRP). arRP with defects in the EYS gene is denoted by "EYS-RP". We previously established a "redirect differentiation" method to generate photosensitive photoreceptor-like cells from commercially available human dermal fibroblasts. In this study, we produced photoreceptor-like cells from dermal fibroblasts of EYS-RP patients as a replacement for the degenerative retinas using "redirect differentiation". We analyzed defective transcripts of the EYS gene in these cells to elucidate phenotypes of EYS-RP patients because decay of transcripts was previously suggested to be involved in phenotypic variation associated with diseases., Methods: Using "redirect differentiation" by CRX, RAX, NeuroD and OTX2, we made photoreceptor-directed fibroblasts derived from three normal volunteers and three EYS-RP patients with homozygous or heterozygous mutations. We tested inducible expression of the photoreceptor-specific genes (blue opsin, rhodopsin, recoverin, S-antigen, PDE6C) in these cells. We then analyzed transcripts derived from three different types of the defective EYS gene, c.1211dupA, c.4957dupA and c.8805C > A, expressed in these cells by RT-PCR and sequencing., Results: Photoreceptor-specific genes including the EYS gene were up-regulated in all the photoreceptor-directed fibroblasts tested. However, expression levels of defective transcripts were markedly different depending on the type of mutation. Transcripts derived from these three defective genes were scarcely detected, expressed at a lower level, and expressed at almost the same level as in normal volunteers, respectively., Conclusions: Expression levels of genetically defective EYS gene transcripts in photoreceptor-directed fibroblasts of EYS-RP patients vary depending on the type of mutation. Variation in expression levels in transcripts having c.1211dupA, c.4957dupA and c.8805C > A suggests that almost complete nonsense-mediated mRNA decay (NMD), partial NMD and escape from NMD occurred for these transcripts, respectively. To determine the relationship with phenotypic variations in EYS-RP patients, more samples are needed. The present study also suggests that the redirect differentiation method could be a valuable tool for disease modeling despite some limitations.
- Published
- 2018
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17. Snoring is associated with an impaired motor function, disease severity and the quality of life but not with excessive daytime sleepiness in patients with Parkinson's disease.
- Author
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Suzuki K, Miyamoto M, Miyamoto T, Suzuki S, Watanabe Y, Numao A, Iwanami M, Tatsumoto M, Sada T, Kadowaki T, Hashimoto K, Sakuta H, and Hirata K
- Subjects
- Aged, Case-Control Studies, Cross-Sectional Studies, Disorders of Excessive Somnolence physiopathology, Disorders of Excessive Somnolence psychology, Female, Humans, Male, Middle Aged, Motor Skills Disorders physiopathology, Motor Skills Disorders psychology, Parkinson Disease physiopathology, Parkinson Disease psychology, Snoring physiopathology, Snoring psychology, Disorders of Excessive Somnolence epidemiology, Motor Skills Disorders epidemiology, Parkinson Disease epidemiology, Quality of Life psychology, Severity of Illness Index, Snoring epidemiology
- Abstract
Objective: There are conflicting results regarding the frequency and clinical significance of sleep related breathing disorders in patients with Parkinson's disease (PD). The aim of this study was to investigate the relationship between snoring and its clinical correlates in patients with PD., Methods: A total of 93 PD patients and 93 controls were analyzed from a previously conducted cross-sectional study. Snoring was defined as a snoring frequency of ≥ 2 days/week (a score of 2 or higher on the PD Sleep Scale-2 subitem 15). Excessive daytime sleepiness (EDS) was defined as an Epworth Sleepiness Scale score of ≥ 10., Results: Snoring was more prevalent in the patients with PD than in the controls (14.0% vs. 1.1%). The PD patients who snored exhibited greater disease severity, worse scores on the motor section of the Unified Parkinson's Disease Rating Scale (UPDRS) and the Parkinson fatigue scale and more impaired scores in several domains of the Parkinson's Disease Questionnaire, including the domains of mobility, activities of daily living, emotional well-being, communication and bodily discomfort, when compared to those who did not snore. No between-group differences were found in EDS. A higher proportion of the UPDRS motor scores for bradykinesia was seen in the PD patients who snored compared to that observed in the PD patients who did not snore., Conclusion: We found that snoring was more frequent in PD patients than in controls. Furthermore, snoring in PD patients was associated with disease severity, an impaired motor function and a decreased quality of life, although it was not associated with EDS.
- Published
- 2013
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18. High prevalence of mutations in the EYS gene in Japanese patients with autosomal recessive retinitis pigmentosa.
- Author
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Iwanami M, Oshikawa M, Nishida T, Nakadomari S, and Kato S
- Subjects
- Adult, Aged, Asian People genetics, Case-Control Studies, Female, Genes, Recessive genetics, Genetic Predisposition to Disease, Genetic Testing, Humans, Male, Middle Aged, Exons genetics, Eye Proteins genetics, Mutation genetics, Retinitis Pigmentosa genetics
- Abstract
Purpose: To screen for disease-causing mutations in the Eyes shut homolog (EYS) gene in Japanese patients with retinitis pigmentosa (RP). Methods. Blood samples were obtained from 68 RP patients and 68 controls. Genomic DNA was extracted from the blood samples and used for screening of mutations in the coding exons by direct sequencing. Each patient underwent a detailed clinical examination., Results: Nine nucleotide sequence variations causing amino acid changes were observed in homozygous or heterozygous alleles in 26 patients but not in 68 controls. Seven truncating mutations were found in 21 (32.8%) of 64 patients with nonsyndromic RP composed of 23 autosomal recessive RP (arRP) and 41 sporadic cases. The most abundant mutation was p.S1653Kfs*2, which was generated by a single adenine insertion into exon 26 (c.4957dupA) and was carried by 15 patients. The mutation p.Y2935*, produced by a single nucleotide substitution (c.8805C>A) in the last exon, was carried by five patients. These two truncating mutations were probably founder mutations because each was carried by the particular haplotype. The patients with homozygous or compound heterozygous truncating mutations showed a severe decline in visual acuity, whereas those with a single truncating mutation showed a mild decline., Conclusions: One-third of Japanese patients with nonsyndromic arRP carried probable pathogenic mutations in the EYS gene, including two founder mutations. Because the genotype was correlated with the phenotype, genotyping in the EYS gene could be a valuable tool for predicting long-term prognoses of Japanese patients with arRP and thus could be useful for genetic counseling and future gene therapy.
- Published
- 2012
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19. Idiopathic REM Sleep Behavior Disorder: Implications for the Pathogenesis of Lewy Body Diseases.
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Miyamoto T, Miyamoto M, Iwanami M, and Hirata K
- Abstract
Objectives. Both results of the odor identification and cardiac (123)I-metaiodobenzylguanidine accumulation have been investigated for their potential to enhance the detection of pathogenesis resembling that of Lewy body-related α-synucleinopathies in patients clinically diagnosed as having idiopathic REM sleep behavior disorder. Methods. We performed both the Odor Stick Identification Test for Japanese and (123)I-metaiodobenzylguanidine scintigraphy in 30 patients with idiopathic REM sleep behavior disorder, 38 patients with Parkinson's disease, and 20 control subjects. Results. In idiopathic REM sleep behavior disorder, reduced odor identification score and an early or delayed heart to mediastinum ratio on (123)I-metaiodobenzylguanidine were almost as severe as in Parkinson's disease patients. Delayed cardiac (123)I-metaiodobenzylguanidine uptake was even more severe in the idiopathic REM sleep behavior disorder group than in the Parkinson's disease group. Conclusions. Reduced cardiac (123)I-metaiodobenzylguanidine uptake, which is independent of parkinsonism, may be more closely associated with idiopathic REM sleep behavior disorder than olfactory impairment.
- Published
- 2011
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20. Sleep disturbances associated with Parkinson's disease.
- Author
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Suzuki K, Miyamoto M, Miyamoto T, Iwanami M, and Hirata K
- Abstract
Sleep disturbances are common problems affecting the quality life of Parkinson's disease (PD) patients and are often underestimated. The causes of sleep disturbances are multifactorial and include nocturnal motor disturbances, nocturia, depressive symptoms, and medication use. Comorbidity of PD with sleep apnea syndrome, restless legs syndrome, rapid eye movement sleep behavior disorder, or circadian cycle disruption also results in impaired sleep. In addition, the involvement of serotoninergic, noradrenergic, and cholinergic neurons in the brainstem as a disease-related change contributes to impaired sleep structures. Excessive daytime sleepiness is not only secondary to nocturnal disturbances or dopaminergic medication but may also be due to independent mechanisms related to impairments in ascending arousal system and the orexin system. Notably, several recent lines of evidence suggest a strong link between rapid eye movement sleep behavior disorder and the risk of neurodegenerative diseases such as PD. In the present paper, we review the current literature concerning sleep disorders in PD.
- Published
- 2011
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21. Cell-type specific utilization of multiple negative feedback loops generates developmental constancy.
- Author
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Iwanami M, Hiromi Y, and Okabe M
- Subjects
- Animals, DNA-Binding Proteins metabolism, Drosophila Proteins metabolism, Enzyme Activation, Epidermal Growth Factor antagonists & inhibitors, Epidermal Growth Factor pharmacology, Eye cytology, Eye embryology, Eye Proteins metabolism, Genes, ras, Membrane Proteins metabolism, Mitogen-Activated Protein Kinases metabolism, Mutagenesis, Site-Directed, Mutation, Nerve Tissue Proteins metabolism, Neurons cytology, Photoreceptor Cells, Invertebrate metabolism, Receptors, Steroid metabolism, Signal Transduction, Drosophila melanogaster embryology, Drosophila melanogaster genetics, Eye metabolism, Feedback, Physiological, Gene Expression Regulation, Developmental, Neurons metabolism, Photoreceptor Cells, Invertebrate embryology
- Abstract
Signaling pathways generally contain multiple negative regulators that are induced by the signal they repress, constructing negative feedback loops. Although such negative regulators are often expressed in a tissue- or cell-type specific manner during development, little is known about the significance of their differential expression patterns and possible interactions. We show the role and interplay of two cell-type specific negative feedback loops during specification of photoreceptor neurons in the Drosophila compound eye, a process that occurs via epidermal growth factor (EGF)-mediated sequential induction through the activation of the Ras/MAPK signaling pathway. Inducing cells secreting EGF express a negative regulator Sprouty (SPRY) that lowers Ras/MAPK signaling activity, and as a consequence reduces the signal-dependent expression of a secreted EGF inhibitor, Argos (AOS). Induced cells in turn express an orphan nuclear receptor Seven-up (SVP), which represses SPRY expression thereby allowing expression and secretion of AOS, preventing further induction. When this intricate system fails, as in spry mutants, sequential induction is no longer constant and the number of photoreceptor neurons becomes variable. Thus, cell-type specific utilization of multiple negative feedback loops not only confers developmental robustness through functional redundancy, but is a key component in generating consistent patterning.
- Published
- 2005
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22. Combination effects of interferon-gamma and cholera toxin on induction of differentiation of an insensitive U-937 clone.
- Author
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Iwanami M, Takeda K, Iwamoto S, and Konno K
- Subjects
- Cell Differentiation drug effects, Cyclic AMP metabolism, Dose-Response Relationship, Drug, Drug Resistance, Drug Synergism, Humans, Leukemia, Myeloid metabolism, Nitroblue Tetrazolium metabolism, Oxidation-Reduction, Tumor Cells, Cultured drug effects, Tumor Cells, Cultured metabolism, Cholera Toxin pharmacology, Interferon-gamma pharmacology, Leukemia, Myeloid pathology
- Abstract
We examined the combination effect of interferon-gamma (IFN-gamma) and cholera toxin and the role of cAMP in the induction of differentiation of a differentiation-insensitive U-937 clone, in which the reactivity to differentiation-inducers was decreased. IFN-gamma (100 units/ml) or cholera toxin (10(-9) M) alone only marginally induced various differentiation-associated characteristics such as NBT-reducing activity, phagocytic activity, a-naphthyl acetate esterase activity and surface markers. However, when combined with each other, they significantly induced these markers. Other cAMP-inducing agents such as prostaglandin E2, forskolin, epinephrine and isoproterenol did not induce NBT-reducing activity, either alone or in combination with IFN-gamma. However, all these cAMP-inducing agents significantly increased intracellular cAMP levels. Tumor necrosis factor, interleukin 6 or granulocyte/macrophage colony-stimulating factor alone did not induce NBT-reducing activity, but they could induce activity when combined with cholera toxin. These results suggest that enhancement of induction of differentiation by cholera toxin in combination with IFN-gamma or other cytokines may not be merely due to increased cAMP levels. There seems to be a transduction signal other than cAMP coupling with cholera toxin to stimulate induction of differentiation of an insensitive U-937 clone.
- Published
- 1990
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23. Synthesis of new cephamycin derivatives and a novel rearrangement between isothiazolethioacetamides and 1,3-dithietanecarboxamides.
- Author
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Iwanami M, Maeda T, Fujimoto M, Nagano Y, Nagano N, Yamazaki A, Shibanuma T, Tamazawa K, and Yano K
- Subjects
- Bacteria drug effects, Cephamycins pharmacology, Chemical Phenomena, Chemistry, Acetamides, Cephalosporins chemical synthesis, Cephamycins chemical synthesis, Heterocyclic Compounds, Thiazoles, Thioacetamide analogs & derivatives
- Published
- 1980
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24. Synthesis of new water-soluble dihydropyridine vasodilators.
- Author
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Iwanami M, Shibanuma T, Fujimoto M, Kawai R, Tamazawa K, Takenaka T, Takahashi K, and Murakami M
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- Nicardipine, Nifedipine analogs & derivatives, Nifedipine pharmacology, Pyridines analogs & derivatives, Solubility, Structure-Activity Relationship, Water, Nifedipine chemical synthesis, Pyridines pharmacology, Vasodilator Agents chemical synthesis
- Published
- 1979
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