72 results on '"Matsukura K"'
Search Results
2. Role of mycorrhizal associations in tree spatial distribution patterns based on size class in an old-growth forest
- Author
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Sasaki, T., Konno, M., Hasegawa, Y., Imaji, A., Terabaru, M., Nakamura, R., Ohira, N., Matsukura, K., and Seiwa, K.
- Published
- 2019
3. Dynamics of Neotyphodium uncinatum and N-formylloline in Italian ryegrass, and their relation to insect resistance in the field
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Matsukura, K., Shiba, T., Sasaki, T., Yoshida, K., and Matsumura, M.
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- 2014
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4. Recent infection by Wolbachia alters microbial communities in wild Laodelphax striatellus populations
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Xing-Zhi Duan, Jing-Tao Sun, Lin-Ting Wang, Xiao-Han Shu, Yan Guo, Matsukura Keiichiro, Yu-Xi Zhu, Xiao-Li Bing, Ary A. Hoffmann, and Xiao-Yue Hong
- Subjects
Laodelphax striatellus ,Microbial community ,Wolbachia ,Endosymbiont ,Microbial interactions ,Microbial ecology ,QR100-130 - Abstract
Abstract Background Host-associated microbial communities play an important role in the fitness of insect hosts. However, the factors shaping microbial communities in wild populations, including genetic background, ecological factors, and interactions among microbial species, remain largely unknown. Results Here, we surveyed microbial communities of the small brown planthopper (SBPH, Laodelphax striatellus) across 17 geographical populations in China and Japan by using 16S rRNA amplicon sequencing. Using structural equation models (SEM) and Mantel analyses, we show that variation in microbial community structure is likely associated with longitude, annual mean precipitation (Bio12), and mitochondrial DNA variation. However, a Wolbachia infection, which is spreading to northern populations of SBPH, seems to have a relatively greater role than abiotic factors in shaping microbial community structure, leading to sharp decreases in bacterial taxon diversity and abundance in host-associated microbial communities. Comparative RNA-Seq analyses between Wolbachia-infected and -uninfected strains indicate that the Wolbachia do not seem to alter the immune reaction of SBPH, although Wolbachia affected expression of metabolism genes. Conclusion Together, our results identify potential factors and interactions among different microbial species in the microbial communities of SBPH, which can have effects on insect physiology, ecology, and evolution. Video Abstract
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- 2020
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5. Tolerance to low temperature and desiccation in two invasive apple snails, Pomacea Canaliculata and P. Maculata (Caenogastropoda: Ampullariidae), collected in their original distribution area (northern and central Argentina)
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Yoshida, K., primary, Matsukura, K., additional, Cazzaniga, N. J., additional, and Wada, T., additional
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- 2014
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6. Dynamics of Neotyphodium uncinatum and N -formylloline in Italian ryegrass, and their relation to insect resistance in the field
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Matsukura, K., primary, Shiba, T., additional, Sasaki, T., additional, Yoshida, K., additional, and Matsumura, M., additional
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- 2013
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7. High pressure synthesis and magnetic properties of CaFe2O4-type NaMn2O4and LiMn2O4
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Tokiwa, K, primary, Matsukura, K, additional, Kasahara, S, additional, Tsuda, S, additional, Mikusu, S, additional, Takeuchi, K, additional, Iyo, A, additional, Tanaka, Y, additional, Akimoto, J, additional, Awaka, J, additional, Kijima, N, additional, Takahashi, Y, additional, and Watanabe, T, additional
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- 2009
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8. Upgrading rural Japanese nurses’ respiratory rehabilitation skills through videoconferencing
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Sawada, I, primary, Sugiyama, A, additional, Ishikawa, A, additional, Ohyanagi, T, additional, Saeki, K, additional, Izumi, H, additional, Kawase, S, additional, and Matsukura, K, additional
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- 2000
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9. Theorie und Praxis der Säulenchromatographie
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Funakubo, E., Nagai, T., and Matsukura, K.
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- 1970
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10. Theorie und Praxis der Säulenchromatographie
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Funakubo, E., Nagai, T., and Matsukura, K.
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- 1963
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11. High pressure synthesis and magnetic properties of CaFe2O4-type NaMn2O4 and LiMn2O4.
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Tokiwa, K., Matsukura, K., Kasahara, S., Tsuda, S., Mikusu, S., Takeuchi, K., Iyo, A., Tanaka, Y., Akimoto, J., Awaka, J., Kijima, N., Takahashi, Y., and Watanabe, T.
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- 2009
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12. Differentiated and Untreated Juvenile Chondrocyte Sheets Regenerate Cartilage Similarly In Vivo .
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Metzler NF, Kondo M, Matsukura K, Ford AJ, Grainger DW, and Okano T
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- Animals, Humans, Rats, Tissue Engineering methods, Male, Cartilage, Articular physiology, Chondrocytes cytology, Cell Differentiation, Regeneration physiology, Rats, Nude
- Abstract
Osteoarthritis, a degenerative disease of articular cartilage and the leading cause of disability, is preceded by acute cartilage injury in a significant proportion of cases. Current auto- and allograft interventions are limited by supply and variability in therapeutic efficacy, prompting interest in tissue engineering solutions. Cell sheet tissue engineering, a scaffold-free regenerative technique, has shown promise in preclinical and clinical trials across various cell types and diseases. Polydactyly-derived juvenile cartilage-derived chondrocyte (JCC) sheets from juvenile patients are a potent cell source for developing allogeneic therapies. JCC sheets have proven safe and effective in animal models and as an add-on therapy in a recent clinical cartilage repair study. However, JCC ex vivo expansion leads to de-differentiation, contributing to long healing times. This study hypothesized that in vitro differentiation of JCC sheets into hyaline-like cartilage constructs could accelerate cartilage regeneration without compromising implant integration. To this end, sheet integration, maturation, and healing of conventionally prepared vs. differentiated JCC sheets were compared in an established nude rat focal chondral defect model. Differentiated JCC sheets exhibit mature cartilage phenotypes prior to transplant. Both conventional and differentiated JCC sheets are reliably transplanted without additional fixation. Histological evaluation reveals that both transplant groups produced equivalent neocartilage regeneration, filling defects with mature hyaline cartilage at 2- and 4-weeks post-transplant. Notably, differentiated JCC sheets respond to in vivo signals, undergoing matrix remodeling and integration with adjacent and subchondral tissue. Given equivalent healing outcomes, the future utility of in vitro JCC sheet predifferentiation from other JCC donors with different healing capacities should be balanced against their increased culture costs over conventional sheets.
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- 2025
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13. Oak Wilt Disease May Reduce the Initial Decay Rate of Dead Quercus serrata Stems by Altering Fungal Communities in the Wood.
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Fukasawa Y, Kimura S, Kominami Y, Takagi M, Matsukura K, Makoto K, Suzuki SN, Takemoto S, Tanaka N, Jomura M, Kadowaki K, Ushio M, Kinuura H, and Yamashita S
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- Japan, Plant Stems microbiology, Forests, Biodiversity, Quercus microbiology, Plant Diseases microbiology, Wood microbiology, Fungi genetics, Fungi classification, Fungi isolation & purification, Mycobiome
- Abstract
Oak wilt causes severe dieback of Quercus serrata, a dominant tree species in the lowlands across Japan. This study evaluated the effects of oak wilt on the wood-inhabiting fungal community and the decay rate of deadwood using a field monitoring experiment. We analysed the fungal metabarcoding community from 1200 wood samples obtained from 120 experimental logs from three forest sites at five different time points during the initial 1.5 years of the experiment. Death due to wilt significantly influenced the fungal community composition and reduced fungal diversity, likely due to the dominance of a limited number of species. The operational taxonomic unit richness, occurrence frequency, and DNA copy number of white rot fungi were also enhanced on the logs killed by wilt, depending on the sites. Structural equation modelling suggested that the wilt-initiated changes in the fungal community reduced the decay rate of oak logs. Temperature and wood moisture also affected the fungal community and log decomposition. These results suggest that, in addition to the direct effect of climate, oak wilt indirectly affects log decomposition by structuring the fungal community. Continuous monitoring is essential to evaluate the longer-term effects of oak wilt on the fungal decomposition of wood., (© 2025 The Author(s). Environmental Microbiology published by John Wiley & Sons Ltd.)
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- 2025
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14. Evaluation of overwintering risk of tropical and subtropical insect pests in temperate regions.
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Matsukura K, Mizutani N, Tanaka S, and Tanaka Y
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- Animals, Insecta physiology, Hemiptera physiology, Risk Assessment, Cold Temperature, Seasons, Tropical Climate, Spodoptera physiology
- Abstract
Recent changes in climate and environments have promoted the range expansion of insect pests of tropical and subtropical origins into temperate regions. For more accurate and faster risk assessment of this expansion, we developed a novel indicator to link a physiologically derived parameter of chilling injury with the survival of insect populations in nature by using two insects, Spodoptera frugiperda and Cicadulina bipunctata with tropical and subtropical origins, and one cool-adapted insect, Laodelphax striatellus. The parameter derived from a proportional increment in the time to 99.9% mortality under constant low temperatures causing chilling injury evaluates the survival of target insect populations based on winter climate data. For S. frugiperda and C. bipunctata, but not for L. striatellus, the accuracy of the model in predicting the overwintering range was equivalent to, or better than, those of a conventional species distribution model. Additional field testing using S. frugiperda and comparison of the developed model with a conventional logistic model for C. bipunctata supported the validity of the indicator. These results suggest that the developed indicator will help for simple risk assessment of tropical and subtropical insect pests in temperate regions by the species distribution modelling approach., Competing Interests: Declarations. Competing interests: The authors declare no competing interests. Ethics approval: All experiments performed in this study requires no ethical approval. Consent to participate: All experiments performed in this study do not require consents to participate and publish., (© 2024. The Author(s).)
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- 2024
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15. Regenerative Variability of Human Juvenile Chondrocyte Sheets From Different Cell Donors in an Athymic Rat Knee Chondral Defect Model.
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Matsukura K, Kondo M, Metzler NF, Ford AJ, Maak TG, Hutchinson DT, Wang AA, Sato M, Grainger DW, and Okano T
- Abstract
Purpose: This study aimed to establish a combined histological assessment system of neo-cartilage outcomes and to evaluate variations in an established rat defect model treated with human juvenile cartilage-derived chondrocyte (JCC) sheets fabricated from various donors., Methods: JCCs were isolated from the polydactylous digits of eight patients. Passage 2 (P2) JCC sheets from all donors were transplanted into nude rat chondral defects for 4 weeks (27 nude rats in total). Defect-only group served as control. Histological samples were stained for safranin O, collagen 1 (COL1), and collagen 2 (COL2). (1) All samples were scored, and correlation coefficients for each score were calculated. (2) Donors were divided into "more effective" and "less effective" groups based on these scores. Then, differences between each group in each category of modified O'Driscoll scoring were evaluated., Results: (1) Modified O'Driscoll scores were negatively correlated with %COL1 area, and positively correlated with %COL2 area and COL2/1 ratio. (2) Four of 8 donors exhibited significantly higher modified O'Driscoll scores and %COL2 areas. JCC donors were divided into two groups by average score values. Significant differences between the two groups were observed in modified O'Driscoll categories of "Nature of predominant tissue," "Reconstruction of subchondral bone," and "Safranin O staining.", Conclusion: The combined histological evaluation method is useful for detailed in vivo efficacy assessments of cartilage defect regeneration models. Variations in histological scores among juvenile cartilage-derived chondrocyte donors were correlated to the quality of regenerated cartilage hyaline structure and subchondral bone remodeling observed in the nude rat defect model., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: Teruo Okano is a shareholder of CellSeed, Inc. and is an inventor/developer designated on the patent for CellSeed’s commercialized thermos-responsive cultureware. Travis Maak discloses the following possible competing interest: Arthrex Inc. (paid speaker and consultant). All other authors declare no competing interests.
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- 2024
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16. The Spread of Southern Rice Black-Streaked Dwarf Virus Was Not Caused by Biological Changes in Vector Sogatella furcifera .
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Matsukura K and Matsumura M
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The pandemic of Southern rice black-streaked dwarf virus (SRBSDV) in and after the late 2000s caused serious yield losses in rice in Southeast and East Asia. This virus was first recorded in China in 2001, but its exclusive vector insect, Sogatella furcifera , occurred there before then. To clarify the evolutionary origin of SRBSDV as the first plant virus transmitted by S. furcifera , we tested virus transmission using three chronological strains of S. furcifera , two of which were established before the first report of SRBSDV. When the strains fed on SRBSDV-infected rice plants were transferred to healthy rice plants, those established in 1989 and 1999 transmitted the virus to rice similarly to the strain established in 2010. SRBSDV quantification by RT-qPCR confirmed virus accumulation in the salivary glands of all three strains. Therefore, SRBSDV transmission by S. furcifera was not caused by biological changes in the vector, but probably by the genetic change of the virus from a closely related Fijivirus , Rice black-streaked dwarf virus, as suggested by ecological and molecular biological comparisons between the two viruses. This result will help us to better understand the evolutionary relationship between plant viruses and their vector insects and to better manage viral disease in rice cropping in Asia., Competing Interests: The authors declare no conflicts of interest.
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- 2024
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17. Acute Leriche Syndrome Mimicking Spinal Cord Infarction: A Case Report.
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Kanbayashi T, Tanaka S, Matsukura K, Sonoo M, and Kobayashi S
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Introduction: Acute Leriche syndrome is a rare but potentially life-threatening condition. Pain, pallor, and coldness of the lower extremities serve as clues for suspecting Leriche syndrome. However, the absence of these findings may pose a diagnostic challenge., Case Presentation: An 83-year-old man presented at our emergency department with a complaint of sudden-onset paraparesis. Initially, spinal cord infarction was suspected due to clinical course and neurological findings, but thoracolumbar MRI showed normal findings. On admission, symptoms associated with aortoiliac occlusion were not present, except for muscle atrophy in the thigh. CT angiography revealed aortoiliac occlusion, leading to a diagnosis of Leriche syndrome., Conclusion: Leriche syndrome should be considered as a potential differential diagnosis in patients with acute paraparesis. Muscle atrophy of the lower limbs disproportionate to the clinical course may be the clue for suspecting acute Leriche syndrome with symptoms related to atherosclerotic occlusion which are inconspicuous., Competing Interests: The authors have no conflicts of interest to declare., (© 2024 The Author(s). Published by S. Karger AG, Basel.)
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- 2024
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18. Prevalence of Poor Sleep Quality and its Association with Lifestyle Habits, Competition-Based Activities, and Psychological Distress in Japanese Student-Athletes During the COVID-19 Pandemic.
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Monma T, Yamashita K, Yoshida G, Fujita E, Miyazawa T, Ebine N, Matsukura K, Takeda S, Matamura M, Yamane M, Ando K, Omi N, Sagayama H, and Takeda F
- Abstract
Objectives The present study clarified the prevalence of poor sleep quality and its relation to lifestyle habits, competitive-based activities, and psychological distress among Japanese student-athletes in the initial pandemic period (2020) and 1 year later (2021). Methods In the present study, student-athletes were defined as individuals belonging to university athletic clubs. The data of two cross-sectional surveys (2020: n = 961 and 2021: n = 711) were collected from student-athletes in 6 universities in Japan. First, the prevalence of poor sleep quality (Pittsburgh sleep quality index score > 5) was investigated. Relationships between poor sleep quality and lifestyle habits, competition-based activities, and psychological distress were then explored using multivariate logistic regression analysis adjusted for age, sex, and body mass index. Results The prevalence of poor sleep quality was 33.6% in 2020 and 36.6% in 2021. Poor sleep quality in 2020 was related to late bedtime, taking supplements before bed, part-time job (no late night), stressors of expectations and pressure from others, and psychological distress, whereas that in 2021 was related to early wake-up time, skipping breakfast, taking caffeinated drinks before bed, use of smartphone/cellphone after lights out, stressors of motivation loss, and psychological distress. Conclusions In both 2020 and 2021, one-third of student-athletes had poor sleep quality and psychological distress was its common risk factor. Lifestyle habits and competition stressors associated with poor sleep quality were pandemic-specific in 2020, but similar to the prepandemic period in 2021., Competing Interests: Conflict of Interests The authors have no conflict of interests to disclose., (Brazilian Sleep Association. This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. ( https://creativecommons.org/licenses/by-nc-nd/4.0/ ).)
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- 2024
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19. 2-Oxo-imidazole dipeptides inhibit peroxynitrite-dependent tyrosine nitration.
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Matsukura K, Komae S, Kasamatsu S, and Ihara H
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- Anserine, Peroxynitrous Acid, Dipeptides pharmacology, Dipeptides chemistry, Imidazoles pharmacology, Imidazoles chemistry, Tyrosine, Carnosine pharmacology, Carnosine chemistry
- Abstract
Carnosine and anserine were reported to inhibit tyrosine nitration. However, there are no reports on the nitration inhibitory activities of balenine, 2-oxo-carnosine, 2-oxo-anserine, and 2-oxo-balenine. We demonstrated for the first time that these compounds exhibit inhibitory activities against peroxynitrite-dependent tyrosine nitration. 2-Oxo-imidazole dipeptides (2-oxo-IDPs) showed higher inhibitory activity than their precursor IDPs, thereby suggesting that 2-oxo-IDPs may be effective against nitrative stress-related diseases., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)
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- 2023
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20. Quantitative Effects of Temperature and Exposure Duration on the Occurrence and Repair of Indirect Chilling Injury in the Fall Armyworm Spodoptera frugiperda .
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Tanaka Y and Matsukura K
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The fall armyworm (FAW) Spodoptera frugiperda is a long-distance migratory insect pest, and the invaded range of its recent expansion includes regions colder than the tropical and subtropical regions in East Asia. In order to understand the potential distribution of S. frugiperd in temperate and colder regions, we quantified the effects of temperature and exposure duration on the degree of indirect chilling injury caused to S. frugiperd under laboratory conditions. The adults were more tolerant to moderately low temperatures (3 to 15 °C) than the larvae and pupae. Survival decreased significantly when adult S. frugiperd were exposed to temperatures of 9 °C or lower. A time-temperature model suggested that indirect chilling injury began occurring at 15 °C. Survival was improved by short-term daily exposure to higher temperatures, indicating the existence of a repair mechanism for indirect chilling injury in S. frugiperd . The degree of repair depended on the temperature, but the relationship was not a simple direct proportion. These findings on indirect chilling injury and repair will improve the estimation of the potential distribution of S. frugiperd in temperate and colder regions.
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- 2023
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21. Tibial nerve SEPs in diagnosing lumbar spinal stenosis: The utility of segmental evaluation using P15 and N21.
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Matsukura K, Hokkoku K, Mukai T, Oishi C, Kanbayashi T, Takahashi T, and Sonoo M
- Abstract
Objective: To establish the utility of the additional evaluation of the P15 potential generated at the greater sciatic foramen in the tibial nerve somatosensory evoked potentials (SEPs) in diagnosing lumbar spinal stenosis (LSS)., Methods: We retrospectively reviewed tibial nerve SEP findings in patients having MRI-confirmed LSS at the cauda equina or conus/epiconus region. P15 and N21 potentials were recorded and the following findings were defined as localizing abnormalities: 1) normal P15 latency either with prolonged P15-N21 interval or with absent N21; 2) decreased ratio of the N21 amplitude to P15 amplitude. As non-localizing abnormalities, N21 and P38 latencies were also evaluated. Tibial nerve F-wave findings were also investigated., Results: According to the entry criteria, 18 patients were included, 15 with cauda equina lesions and 3 with conus/epiconus lesions. Localizing abnormalities in SEPs were found in 67% of patients, achieving significantly higher sensitivity than delayed P38 latency (28%), and higher sensitivity than N21 abnormalities (39%), though this was not significant. Localizing abnormalities were observed even in 6 out of 11 patients lacking both sensory symptoms and signs. Tibial nerve F-wave was abnormal in 36% of 14 patients with F-wave examinations, whereas the localizing abnormalities in SEPs were found in 64% of the same patient population. P15 amplitude was depressed in 4 patients (22%), which may indicate the involvement of the dorsal root ganglion in LSS, although its latency was normal even for these patients., Conclusions: Tibial nerve SEPs with the recording of P15 and N21 potentials achieved sufficiently high sensitivity in diagnosing LSS. They have the advantage over F-wave in that they can localize the lesion at the cauda equina or conus/epiconus level., Significance: Tibial nerve SEPs are promising in evaluating LSS, especially in documenting sensory tract involvement in cases lacking sensory symptoms/signs., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 International Federation of Clinical Neurophysiology. Published by Elsevier B.V.)
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- 2023
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22. Genetic evidence of transoceanic migration of the small brown planthopper between China and Japan.
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Zhou XY, Ding Y, Zhou JY, Sun KK, Matsukura K, Zhang H, Chen L, Hong XY, and Sun JT
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- Animals, China, Insecta genetics, Japan, Sequence Analysis, DNA, Hemiptera genetics
- Abstract
Background: The small brown planthopper, Laodelphax striatellus (Fallén), is an important pest of rice. It is suspected of migrating over the sea from China to Japan. However, where in China it comes from and how it affects Japanese populations remain unclear., Results: Here, we studied the genetic structure of 15 L. striatellus populations sampled from Japan and China using single nucleotide polymorphisms generated by the double digest restriction site-associated DNA sequencing technique. We found weak genetic differentiation between the Chinese and Japanese populations. Our data revealed migration signals of L. striatellus from China to southern and northern Japan. However, the source regions of the immigrants remain unclear due to the low genetic differentiation between populations. Our results also pointed to the possibility of backward gene flow from Japanese to Chinese populations. We suspect that the south-eastern wind associated with the East Asian summer monsoon may facilitate the reverse migration of L. striatellus from Japan to China. Interestingly, we found that the X chromosome displayed relatively higher genetic differentiation among populations and suffered more intensive selection pressure than autosomes., Conclusion: We provide genetic evidence of transoceanic migration of L. striatellus from China to Japan and found that the X chromosome can aid the deciphering of the migration trajectories of species with low genetic differentiation. These findings have implications for forecasting the outbreak of this pest and also provide insights into how to improve the tracking of the migration routes of small insects via population genomics. © 2022 Society of Chemical Industry., (© 2022 Society of Chemical Industry.)
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- 2022
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23. 2-Oxo-Imidazole-Containing Dipeptides Play a Key Role in the Antioxidant Capacity of Imidazole-Containing Dipeptides.
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Kasamatsu S, Komae S, Matsukura K, Kakihana Y, Uchida K, and Ihara H
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There is substantial evidence for the antioxidant functions of imidazole-containing dipeptides (IDPs), including carnosine and anserine, under physiological and pathological conditions in vivo. However, the detailed mechanism underlying the antioxidant functions is still poorly understood. Recently, we discovered the endogenous production of 2-oxo-imidazole-containing dipeptides (2-oxo-IDPs), such as 2-oxo-carnosine and 2-oxo-anserine, as novel derivatives of IDPs in mouse tissues and revealed that the antioxidant capacity of 2-oxo-carnosine was much greater than that of carnosine. However, the antioxidant capacity of 2-oxo-IDPs still remains unclear. In this study, we evaluated 2-oxo-carnosine and 2-oxo-anserine by multiple in vitro assays, such as 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, ferric reducing/antioxidant power, and oxygen radical absorbance capacity assays in comparison with the corresponding IDPs, carnosine and anserine. All the assays employed herein demonstrated that 2-oxo-carnosine and 2-oxo-anserine exhibited a greater antioxidant capacity than that of the corresponding IDPs. Quantitative high-performance liquid chromatography tandem mass spectrometry revealed that commercial IDPs standards were contaminated with a certain amount of 2-oxo-IDPs, which was correlated with the antioxidant capacity. DPPH radical scavenging assay revealed that the elimination of contaminated 2-oxo-IDPs from the IDPs standards caused a significant decrease in the antioxidant capacity compared to the original IDPs standards. These results suggest that the main driver of the antioxidant capacity of IDPs is 2-oxo-IDPs; accordingly, the conversion of IDPs to 2-oxo-IDPs may be a critical step in the antioxidant functions.
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- 2021
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24. Decay stages of wood and associated fungal communities characterise diversity-decomposition relationships.
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Fukasawa Y and Matsukura K
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- Biodiversity, Forests, Fungi growth & development, Mycobiome physiology, Wood microbiology
- Abstract
The biodiversity-ecosystem function relationship is a central topic in ecology. Fungi are the dominant decomposers of organic plant material in terrestrial ecosystems and display tremendous species diversity. However, little is known about the fungal diversity-decomposition relationship. We evaluated fungal community assemblies and substrate quality in different stages of wood decay to assess the relationships between fungal species richness and weight loss of wood substrate under laboratory conditions. Wood-inhabiting fungal communities in the early and late stages of pine log decomposition were used as a model. Colonisation with certain species prior to inoculation with other species resulted in four-fold differences in fungal species richness and up to tenfold differences in the rate of wood substrate decomposition in both early- and late-decaying fungal communities. Differences in wood substrate quality had a significant impact on species richness and weight loss of wood and the relationships between the two, which were negative or neutral. Late communities showed significantly negative species richness-decay relationships in wood at all decay stages, whereas negative relationships in early communities were significant only in the intermediate decay stage. Our results suggest that changes in fungal communities and wood quality during wood decomposition affect the fungal diversity-decomposition relationship.
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- 2021
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25. Synthesis and evaluation of azalamellarin N and its A-ring-modified analogues as non-covalent inhibitors of the EGFR T790M/L858R mutant.
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Fukuda T, Anzai M, Nakahara A, Yamashita K, Matsukura K, Ishibashi F, Oku Y, Nishiya N, Uehara Y, and Iwao M
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- Afatinib pharmacology, Cell Line, Tumor, Gefitinib pharmacology, Humans, Models, Molecular, Molecular Structure, Mutation, Protein Conformation, ErbB Receptors antagonists & inhibitors, ErbB Receptors genetics, Heterocyclic Compounds, 4 or More Rings chemical synthesis, Heterocyclic Compounds, 4 or More Rings pharmacology, Protein Kinase Inhibitors chemical synthesis, Protein Kinase Inhibitors pharmacology
- Abstract
Azalamellarin N, a synthetic lactam congener of the marine natural product lamellarin N, and its A-ring-modified analogues were synthesized and evaluated as potent and non-covalent inhibitors of the drug-resistant epidermal growth factor receptor T790M/L858R mutant. An in vitro tyrosine kinase assay indicated that the inhibitory activities of the synthetic azalamellarin analogues were higher than those of the corresponding lamellarins. The azalamellarin analogue bearing two 3-(dimethylamino)propoxy groups at C20- and C21-positions exhibited the highest activity and selectivity against the mutant kinase [IC
50 (T790M/L858R) = 1.7 nM; IC50 (WT) = 4.6 nM]. The inhibitory activity was attributed to the hydrogen bonding interaction between the lactam NH group of the B-ring and carbonyl group of a methionine residue., (Copyright © 2021 Elsevier Ltd. All rights reserved.)- Published
- 2021
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26. Energy Reserve Compensating for Trade-Off Between Metabolic Resistance and Life History Traits in the Brown Planthopper (Hemiptera: Delphacidae).
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Fujii T, Sanada-Morimura S, Matsukura K, Van Chien H, Cuong LQ, Loc PM, Estoy GF, and Matsumura M
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- Animals, Female, Insecticide Resistance, Neonicotinoids, Nitro Compounds, Reproduction, Hemiptera, Insecticides pharmacology, Life History Traits
- Abstract
Development of insecticide resistance often changes life history traits of insect pests, because metabolic detoxification of insecticides in insect bodies requires huge energetic reserves. The brown planthopper, Nilaparvata lugens (Stål), an important insect pest of rice crop in East and Southeast Asia, has developed strong resistance to imidacloprid from mid-2000s. The aim of this study was to examine the costs of life history traits and reveal changes in energy reserves with developing imidacloprid resistance. We compared the life history traits (survival time, fecundity, developmental time, and hatchability) and total lipid content between imidacloprid-resistant and imidacloprid-susceptible (control) brown planthopper strains. As compared to the control strains, adults' survival time of the resistant females was shorter, and their fecundity was lower; the other life history traits did not differ significantly between the resistant and control strains. As the results, net reproductive rates (R0) were lower in the resistant strains than in the susceptible strains. However, the amount of stored lipids was larger in resistant females than control ones. Our findings demonstrated a physiological trade-off between the development of imidacloprid resistance and the reproductive traits of brown planthopper. The imidacloprid-resistant strains are likely to store lipids for metabolic detoxification rather than consume them for reproduction., (© The Author(s) 2020. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)
- Published
- 2020
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27. Examination of the changes in lower extremities related to progression of adult spinal deformity: a longitudinal study of over 22 years.
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Shimizu M, Kobayashi T, Chiba H, Senoo I, Abe S, Matsukura K, and Ito H
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- Adult, Aged, Disease Progression, Female, Humans, Kyphosis physiopathology, Longitudinal Studies, Lordosis physiopathology, Lower Extremity physiopathology, Lumbar Vertebrae diagnostic imaging, Lumbar Vertebrae physiopathology, Middle Aged, Sacrum diagnostic imaging, Sacrum physiopathology, Thoracic Vertebrae diagnostic imaging, Thoracic Vertebrae physiopathology, Kyphosis diagnostic imaging, Lordosis diagnostic imaging, Lower Extremity diagnostic imaging, Posture physiology
- Abstract
This longitudinal observational study investigated the relationship between changes in spinal sagittal alignment and changes in lower extremity coronal alignment. A total of 58 female volunteers who visited our institution at least twice during the 1992 to 1997 and 2015 to 2019 periods were investigated. We reviewed whole-spine radiographs and lower extremity radiographs and measured standard spinal sagittal parameters including pelvic incidence [PI], lumbar lordosis [LL], pelvic tilt [PT], sacral slope [SS] and sagittal vertical axis [SVA], and coronal lower extremity parameters including femorotibial angle (FTA), hip-knee-ankle angle (HKA), mechanical lateral distal femoral angle (mLDFA), mechanical medial proximal tibial angle (mMPTA) and mechanical lateral distal tibial angle (mLDTA). Lumbar spondylosis and knee osteoarthritis were assessed using the Kellgren-Lawrence (KL) grading system at baseline and at final follow-up. We investigated the correlation between changes in spinal sagittal alignment and lower extremity alignment and changes in lumbar spondylosis. The mean age [standard deviation (SD)] was 48.3 (6.3) years at first visit and 70.2 (6.3) years at final follow-up. There was a correlation between changes in PI-LL and FTA (R = 0.449, P < 0.001) and between PI-LL and HKA (R = 0.412, P = 0.001). There was a correlation between changes in lumbar spondylosis at L3/4 (R = 0.383, P = 0.004) and L4/5 (R = 0.333, P = 0.012) and the knee joints. Changes in lumbar spondylosis at L3/4 and L4/5 were related to changes in KOA. Successful management of ASD must include evaluation of the state of lower extremity alignment, not only in the sagittal phase, but also the coronal phase.
- Published
- 2020
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28. Adult spinal deformity and its relationship with height loss: a 34-year longitudinal cohort study.
- Author
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Shimizu M, Kobayashi T, Chiba H, Senoo I, Ito H, Matsukura K, and Saito S
- Subjects
- Adult, Aged, Aged, 80 and over, Female, Follow-Up Studies, Humans, Japan, Longitudinal Studies, Lumbosacral Region, Male, Middle Aged, Quality of Life, Spinal Fusion methods, Thoracic Vertebrae surgery, Body Height, Kyphosis surgery, Lordosis surgery, Lumbar Vertebrae surgery, Scoliosis surgery
- Abstract
Background: Age-related height loss is a normal physical change that occurs in all individuals over 50 years of age. Although many epidemiological studies on height loss have been conducted worldwide, none have been long-term longitudinal epidemiological studies spanning over 30 years. This study was designed to investigate changes in adult spinal deformity and examine the relationship between adult spinal deformity and height loss., Methods: Fifty-three local healthy subjects (32 men, 21 women) from Furano, Hokkaido, Japan, volunteered for this longitudinal cohort study. Their heights were measured in 1983 and again in 2017. Spino-pelvic parameters were compared between measurements obtained in 1983 and 2017. Individuals with height loss were then divided into two groups, those with degenerative spondylosis and those with degenerative lumbar scoliosis, and different characteristics were compared between the two groups., Results: The mean age of the subjects was 44.4 (31-55) years at baseline and 78.6 (65-89) years at the final follow-up. The mean height was 157.4 cm at baseline and 153.6 cm at the final follow-up, with a mean height loss of 3.8 cm over 34.2 years. All parameters except for thoracic kyphosis were significantly different between measurements taken in 1983 and 2017 (p < 0.05). Height loss in both sexes was related to changes in pelvic parameters including pelvic incidence-lumbar lordosis (R = 0.460 p = 0.008 in men, R = 0.553 p = 0.012 in women), pelvic tilt (R = 0.374 p = 0.035 in men, R = 0.540 p = 0.014 in women), and sagittal vertical axis (R = 0.535 p = 0.002 in men, R = 0.527 p = 0.017 in women). Greater height loss was more commonly seen in women (p = 0.001) and in patients with degenerative lumbar scoliosis (p = 0.02)., Conclusions: This longitudinal study revealed that height loss is more commonly observed in women and is associated with adult spinal deformity and degenerative lumbar scoliosis. Height loss is a normal physical change with aging, but excessive height loss is due to spinal kyphosis and scoliosis leading to spinal malalignment. Our findings suggest that height loss might be an early physical symptom for spinal malalignment.
- Published
- 2020
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29. Potential Risks of Poaceous Plants as Infectious Sources of Rice Black-Streaked Dwarf Virus Transmitted by the Small Brown Planthopper, Laodelphax striatellus .
- Author
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Matsukura K, Sanada-Morimura S, Fujii T, and Matsumura M
- Subjects
- Animals, Asia, Eastern, Oryza virology, Triticum virology, Hemiptera virology, Poaceae virology, Reoviridae physiology
- Abstract
The recent reemergence of rice black-streaked dwarf virus (RBSDV) has caused severe rice yield losses in several areas of East Asia. To identify the most important infectious sources of RBSDV, we compared the susceptibility of major poaceous plants to RBSDV infection and survival and the RBSDV acquisition efficiency of a vector insect, the small brown planthopper Laodelphax striatellus . RBSDV infection and survival rates of L. striatellus were significantly high in wheat ( Triticum aestivum 'Norin61') and rice ( Oryza sativa 'Reiho'), indicating that these crops can be important sources of RBSDV. Our results also showed that RBSDV can complete its infection cycle between Italian ryegrass ( Lolium multiflorum 'Hataaoba') and L. striatellus . These results indicate that control of RBSDV and L. striatellus on winter-spring crops of wheat and Italian ryegrass may avoid an RBSDV epidemic on rice during the following summer. In addition to infections of wheat and Italian ryegrass, RBSDV infections were detected in Avena fatua , Avena sterilis subsp. ludoviciana , Cynosurus echinatus , Festuca arundinacea , Festuca pratensis , Lolium perenne , and Vulpia myuros var. megalura , although the infection efficiency varied.
- Published
- 2019
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30. Anti-tumor effects of mAb against L-type amino acid transporter 1 (LAT1) bound to human and monkey LAT1 with dual avidity modes.
- Author
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Ueda S, Hayashi H, Miyamoto T, Abe S, Hirai K, Matsukura K, Yagi H, Hara Y, Yoshida K, Okazaki S, Tamura M, Abe Y, Agatsuma T, Niwa SI, Masuko K, and Masuko T
- Subjects
- A549 Cells, Amino Acids metabolism, Animals, Cell Line, Cell Line, Tumor, Cell Proliferation drug effects, HCT116 Cells, HEK293 Cells, Haplorhini, HeLa Cells, Humans, Macaca fascicularis, Mice, Mice, Nude, Rats, Rats, Inbred F344, Antibodies, Monoclonal pharmacology, Large Neutral Amino Acid-Transporter 1 metabolism
- Abstract
L-Type amino acid transporter 1 (LAT1) disulfide linked to CD98 heavy chain (hc) is highly expressed in most cancer cells, but weakly expressed in normal cells. In the present study, we developed novel anti-LAT1 mAbs and showed internalization activity, inhibitory effects of amino acid uptake and cell growth and antibody-dependent cellular cytotoxicity, as well as in vivo antitumor effects in athymic mice. Furthermore, we examined the reactivity of mAbs with LAT1 of Macaca fascicularis to evaluate possible side-effects of antihuman LAT1 mAbs in clinical trials. Antihuman LAT1 mAbs reacted with ACHN human and MK.P3 macaca kidney-derived cells, and this reactivity was significantly decreased by siRNAs against LAT1. Macaca LAT1 cDNA was cloned from MK.P3, and only two amino acid differences between human and macaca LAT1 were seen. RH7777 rat hepatoma and HEK293 human embryonic kidney cells expressing macaca LAT1 were established as stable transfectants, and antihuman LAT1 mAbs were equivalently reactive against transfectants expressing human or macaca LAT1. Dual (high and low) avidity modes were detected in transfectants expressing macaca LAT1, MK.P3, ACHN and HCT116 human colon cancer cells, and K
A values were increased by anti-CD98hc mAb, suggesting anti-LAT1 mAbs detect an epitope on LAT1-CD98hc complexes on the cell surface. Based on these results, LAT1 may be a promising anticancer target and Macaca fascicularis can be used in preclinical studies with antihuman LAT1 mAbs., (© 2018 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.)- Published
- 2019
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31. Increased uptake on 18 F-fluorodeoxyglucose positron emission tomography/computed tomography is indicative of occult skin lesions in a patient with intravascular large B-cell lymphoma.
- Author
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Matsukura K, Hokkoku K, Shiraoka A, Yang L, Takahashi Y, Hatanaka Y, Sasajima Y, Tada Y, and Sonoo M
- Subjects
- Aged, Biopsy, Fluorodeoxyglucose F18 administration & dosage, Humans, Lymphoma, B-Cell pathology, Male, Neoplasm Invasiveness diagnostic imaging, Neoplasm Invasiveness pathology, Positron Emission Tomography Computed Tomography methods, Radiopharmaceuticals administration & dosage, Skin blood supply, Skin pathology, Skin Neoplasms pathology, Lymphoma, B-Cell diagnostic imaging, Skin Neoplasms diagnostic imaging
- Published
- 2018
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32. Quantitative muscle ultrasound is useful for evaluating secondary axonal degeneration in chronic inflammatory demyelinating polyneuropathy.
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Hokkoku K, Matsukura K, Uchida Y, Kuwabara M, Furukawa Y, Tsukamoto H, Hatanaka Y, and Sonoo M
- Subjects
- Adult, Aged, Arm pathology, Arm physiopathology, Biopsy methods, Diagnosis, Differential, Electromyography methods, Female, Humans, Male, Middle Aged, Neural Conduction physiology, Axons pathology, Muscle, Skeletal diagnostic imaging, Muscle, Skeletal innervation, Polyradiculoneuropathy, Chronic Inflammatory Demyelinating diagnosis, Polyradiculoneuropathy, Chronic Inflammatory Demyelinating physiopathology, Ultrasonography methods
- Abstract
Introduction: In chronic inflammatory demyelinating polyneuropathy (CIDP), exclusion of secondary axonal degeneration is challenging with conventional methods such as nerve conduction study (NCS), needle electromyography, and nerve biopsy. Increased echo intensity (EI) and decreased muscle thickness (MT) identified on muscle ultrasound (MUS) examination represent muscle denervation due to axonal degeneration in neurogenic disorders, suggesting MUS as a new tool to detect secondary axonal degeneration in patients with CIDP., Methods: EI and MT of abductor pollicis brevis, abductor digiti minimi, and first dorsal interosseous muscles were measured in 16 CIDP patients. Raw values were converted into z -scores using data from 60 normal controls (NCs)., Results: Six of 45 muscles showed abnormally high EI and low MT, suggesting denervation following secondary axonal degeneration. These six muscles belonged to two patients with long disease history, unresponsiveness to treatment, and long interval from onset to initial therapy. There were no significant differences in EI and MT ( p = .23 and .67, respectively) between the CIDP and NC groups, although NCS results revealed obvious demyelinating abnormalities in all CIDP patients, suggesting the fact that muscle structures will be preserved, and EI and MT will not change unless secondary axonal degeneration occurs in CIDP., Conclusion: MUS is a promising tool for evaluating secondary axonal degeneration in patients with CIDP.
- Published
- 2017
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33. Isolated cerebellar-type hemiataxia in a thalamic infarction.
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Hokkoku K, Matsukura K, Yamamoto J, Kuwabara M, Chiba T, Hatanaka Y, and Sonoo M
- Subjects
- Aged, Brain Infarction pathology, Cerebellar Ataxia pathology, Female, Humans, Magnetic Resonance Imaging, Brain Infarction complications, Cerebellar Ataxia etiology, Thalamus pathology
- Published
- 2016
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34. Quantitative Analysis of Southern rice black-streaked dwarf virus in Sogatella furcifera and Virus Threshold for Transmission.
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Matsukura K, Towata T, Yoshida K, Sakai J, Okuda M, Onuki M, and Matsumura M
- Subjects
- Animals, Capsid Proteins genetics, Female, Male, RNA, Viral genetics, Real-Time Polymerase Chain Reaction, Reoviridae isolation & purification, Viral Proteins genetics, Hemiptera virology, Insect Vectors virology, Oryza virology, Plant Diseases virology, Reoviridae genetics
- Abstract
We investigated Southern rice black-streaked dwarf virus (SRBSDV) accumulation in a vector insect, the whitebacked planthopper (Sogatella furcifera), to elucidate the association of virus accumulation in the vector with virus transmission efficiency. Real-time quantitative reverse transcription polymerase chain reaction analysis confirmed that this virus is transmitted in a persistent-propagative manner. SRBSDV was successfully transmitted by S. furcifera males in which RNA accumulation of the capsid protein gene of SRBSDV was >10(3) in the whole body of S. furcifera, indicating that the threshold accumulation of the virus RNA for virus transmission is 10(3) in an S. furcifera male. The SRBSDV detection rate in the immigrant population of S. furcifera was high in 2011 (39.5%); however, most of the insects contained fewer than 10(3) RNAs of the capsid protein gene. This result indicates that the risk of SRBSDV epidemics could be estimated from the proportion of virus-transmissible S. furcifera (i.e., S. furcifera that contained more than 10(3) RNAs of the virus capsid protein gene) rather than the SRBSDV detection rate in S. furcifera.
- Published
- 2015
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35. ¹³⁷Cs concentrations in foliose lichens within Tsukuba-city as a reflection of radioactive fallout from the Fukushima Dai-ichi Nuclear Power Plant accident.
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Ohmura Y, Matsukura K, Abe JP, Hosaka K, Tamaoki M, Dohi T, Kakishima M, and Seaward MR
- Subjects
- Cities, Japan, Seasons, Air Pollutants, Radioactive metabolism, Cesium Radioisotopes metabolism, Fukushima Nuclear Accident, Lichens metabolism, Radioactive Fallout analysis
- Abstract
(137)Cs concentrations in ten species of foliose lichens collected within Tsukuba-city in August 2013 ranged from 1.7 to 35 kBq/kg. The relationships between (137)Cs in two dominant species, Dirinaria applanata and Physcia orientalis, and the air dose rate (μSv/h) at the sampling sites were investigated. (137)Cs in P. orientalis measured about 1 year after the Fukushima nuclear accident was correlated (r(2) = 0.80) more closely with the air dose rate than those measured after about 2 years (r(2) = 0.65), possibly demonstrating its continued value as a biomonitor to reflect ambient fall-out levels. In contrast, those of Dirinaria applanata were not correlated with the air dose rate in either year., (Copyright © 2014 Elsevier Ltd. All rights reserved.)
- Published
- 2015
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36. Cold tolerance of the maize orange leafhopper, Cicadulina bipunctata.
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Matsukura K, Izumi Y, Kumashiro S, and Matsumura M
- Subjects
- Animals, Female, Introduced Species, Japan, Male, Sex Factors, Acclimatization, Cold Temperature adverse effects, Freezing adverse effects, Hemiptera physiology
- Abstract
Cicadulina bipunctata was originally distributed in tropical and subtropical regions of the Old World. This leafhopper recently expanded its distribution area to southern parts of temperate Japan. In this study, factors affecting the overwintering ability of C. bipunctata were examined. A series of laboratory experiments revealed that cold acclimation at 15°C for 7days enhanced the cold tolerance of C. bipunctata to the same level as an overwintering population, adult females were more tolerant of cold temperature than adult males, and survival of acclimated adult females was highly dependent on temperature from -5 to 5°C and exposure duration to the temperature. The temperature of crystallization of adult females was approximately -19°C but temperatures in southern temperate Japan rarely dropped below -10°C in the winter, indicating that overwintering C. bipunctata adults in temperate Japan are not killed by freezing injury but by indirect chilling injury caused by long-term exposure to moderately low temperatures. An overwintering generation of C. bipunctata had extremely low overwinter survival (<1%) in temperate Japan; however, based on winter temperature ranges, there are additional areas amenable to expansion of C. bipunctata in temperate Japan., (Copyright © 2014 Elsevier Ltd. All rights reserved.)
- Published
- 2014
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37. Detection and diagnosis of rice-infecting viruses.
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Uehara-Ichiki T, Shiba T, Matsukura K, Ueno T, Hirae M, and Sasaya T
- Abstract
Rice-infecting viruses have caused serious damage to rice production in Asian, American, and African countries, where about 30 rice viruses and diseases have been reported. To control these diseases, developing accurate, quick methods to detect and diagnose the viruses in the host plants and any insect vectors of the viruses is very important. Based on an antigen-antibody reaction, serological methods such as latex agglutination reaction and enzyme-linked immunosorbent assay have advanced to detect viral particles or major proteins derived from viruses. They aid in forecasting disease and surveying disease spread and are widely used for virus detection at plant protection stations and research laboratories. From the early 2000s, based on sequence information for the target virus, several other methods such as reverse transcription-polymerase chain reaction (RT-PCR) and reverse transcription-loop-mediated isothermal amplification have been developed that are sensitive, rapid, and able to differentiate closely related viruses. Recent techniques such as real-time RT-PCR can be used to quantify the pathogen in target samples and monitor population dynamics of a virus, and metagenomic analyses using next-generation sequencing and microarrays show potential for use in the diagnosis of rice diseases.
- Published
- 2013
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38. Dynamics of Southern rice black-streaked dwarf virus in rice and implication for virus acquisition.
- Author
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Matsukura K, Towata T, Sakai J, Onuki M, Okuda M, and Matsumura M
- Subjects
- Animals, Asia, Southeastern, Oryza growth & development, Real-Time Polymerase Chain Reaction, Reoviridae genetics, Reoviridae growth & development, Reverse Transcription, Seedlings growth & development, Seedlings virology, Hemiptera virology, Insect Vectors virology, Oryza virology, Plant Diseases virology, Reoviridae isolation & purification
- Abstract
A novel viral disease of rice caused by Southern rice black-streaked dwarf virus (SRBSDV) has spread throughout East and Southeast Asia since the mid-2000s. Outbreaks of this viral disease occur yearly in southern parts of Japan concurrently with overseas migration of the planthopper vector Sogatella furcifera from southern China during the rainy season (from late June to early July). We examined the dynamics (changes in titer and localization) of SRBSDV on rice using reverse-transcription real-time polymerase chain reaction and determined the relationship between virus titer in plants and virus acquisition by S. furcifera. Under a constant temperature of 27°C, a substantial increase of SRBSDV titer in the leaf sheath together with typical symptoms (stunted growth and twisting of leaf tips) was observed at 20 days after the end of a 7-day exposure of viruliferous S. furcifera. Approximately 40% of S. furcifera acquired SRBSDV through feeding for 5 days on rice plants that were infected following exposure to viruliferous vectors for 10 to 15 days. These results suggest that rice infected by S. furcifera can be a source of SRBSDV before the next generation of S. furcifera emerges.
- Published
- 2013
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39. Phytohormones related to host plant manipulation by a gall-inducing leafhopper.
- Author
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Tokuda M, Jikumaru Y, Matsukura K, Takebayashi Y, Kumashiro S, Matsumura M, and Kamiya Y
- Subjects
- Animals, Male, Plant Growth Regulators analysis, Plant Leaves physiology, Water metabolism, Hemiptera physiology, Herbivory physiology, Plant Growth Regulators metabolism, Zea mays physiology
- Abstract
The maize orange leafhopper Cicadulina bipunctata (Hemiptera: Cicadellidae) induces galls characterized by growth stunting and severe swelling of leaf veins on various plants of Poaceae. Previous studies revealed that galls are induced not on feeding site but on distant, newly extended leaves during the feeding, and strongly suggested that some chemicals injected by the leafhopper affect at the leaf primordia. To approach the mechanism underlying gall induction by C. bipunctata, we examined physiological response of plants to feeding by the leafhopper. We performed high-throughput and comprehensive plant hormone analyses using LC-ESI-MS/MS. Galled maize leaves contained higher contents of abscisic acid (ABA) and trans-Zeatin (tZ) and lower contents of gibberellins (GA1 and GA4) than ungalled maize leaves. Leafhopper treatment significantly increased ABA and tZ contents and decreased GA1 and GA4 contents in extending leaves. After the removal of leafhoppers, contents of tZ and gibberellins in extending leaves soon became similar to the control values. ABA content was gradually decreased after the removal of leafhoppers. Such hormonal changes were not observed in leafhopper treatment on leaves of resistant maize variety. Water contents of galled leaves were significantly lower than control leaves, suggesting water stress of galled leaves and possible reason of the increase in ABA content. These results imply that ABA, tZ, and gibberellins are related to gall induction by the leafhopper on susceptible variety of maize.
- Published
- 2013
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40. Enhanced resistance to four species of Clypeorrhynchan pests in Neotyphodium uncinatum infected Italian ryegrass.
- Author
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Matsukura K, Shiba T, Sasaki T, and Matsumura M
- Subjects
- Animals, Endophytes chemistry, Feeding Behavior, Hemiptera physiology, Japan, Lolium chemistry, Neotyphodium chemistry, Nymph drug effects, Nymph physiology, Phloem chemistry, Phloem microbiology, Population Dynamics, Species Specificity, Xylem chemistry, Xylem microbiology, Hemiptera drug effects, Lolium microbiology, Neurotoxins pharmacology, Pyrrolizidine Alkaloids pharmacology
- Abstract
Particular alkaloids produced by Neotyphodium endophytes show toxicity to invertebrates. Italian ryegrass (Lolium multiflorum Lamarck) cultivars and strains that are symbiotic with Neotyphodium endophytes have been recently established in Japan. N. uncinatum-infected Italian ryegrass lines accumulate N-formylloline, a type of loline alkaloid (1-aminopyrrolizidine) showing neurotoxicity to herbivorous insects. This study investigated the toxicity of N-formylloline and resistance of N. uncinatum-infected Italian ryegrass to vascular-sap feeding Clypeorrhynchan pests. When four vascular-sap feeding insects: Laodelphax striatellus (Fallén) (Homoptera: Delphacidae), Sogatella furcifera (Horváth) (Homoptera: Delphacidae), Cicadulina bipunctata (Melichar) (Homoptera: Cicadellidae), and Nephotettix cincticeps (Uhler) (Homoptera: Cicadellidae) fed on N. uncinatum-infected Italian ryegrass, significant decreases in survival rate were observed for three phloem-sap feeders but not for a xylem-sap feeder, N. cincticeps. This result suggests an uneven distribution of N-formylloline among plant tissues. A potency assay for N-formylloline using a Parafilm feeding sachet and a quantitative analysis of N-formylloline in plant showed a concentration-dependent lethal effect of N-formylloline on all four tested vascular-sap feeders. Our results strongly suggest that N. uncinatum-infected plants can control some Clypeorrhynchan pests in crop fields.
- Published
- 2012
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41. Effect of barley chromosome addition on the susceptibility of wheat to feeding by a gall-inducing leafhopper.
- Author
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Kumashiro S, Matsukura K, Kawaura K, Matsumura M, Ogihara Y, and Tokuda M
- Subjects
- Animals, Host-Parasite Interactions genetics, Linear Models, Plant Tumors genetics, Triticum growth & development, Chromosomes, Plant genetics, Hemiptera physiology, Hordeum genetics, Triticum genetics, Triticum parasitology
- Abstract
The maize orange leafhopper Cicadulina bipunctata is distributed widely in tropical and subtropical regions of the Old World and feeds on various Poaceae. The leafhopper is recognized as an important pest of maize in several countries. Adults as well as nymphs of C. bipunctata induce growth stunting and galls characterized by the severe swelling of leaf veins on many cereal crops including wheat, rice, and maize, but do not on barley. To clarify the mechanism of growth stunting and gall induction by C. bipunctata, we used six barley chromosome disomic addition lines of wheat (2H-7H) and investigated the effect of barley (cv. Betzes) chromosome addition on the susceptibility of wheat (cv. Chinese Spring) to feeding by the leafhopper. Feeding by C. bipunctata significantly stunted the growth in 2H, 3H, 4H, and 5H, but did not in 6H and 7H. The degree of gall induction was significantly weaker and severer in 3H and 5H than in Chinese Spring, respectively. These results suggest that barley genes resistant to growth stunting and gall induction exist in 6H and 7H, and 3H, respectively. 5H is considered to be useful for future assays investigating the mechanism of gall induction by this leafhopper because of the high susceptibility to the feeding by C. bipunctata. Significant correlation between the degrees of growth stunting and gall induction was not detected in the six chromosome addition lines and Chinese spring. This implies that these two symptoms are independent phenomena although both are initiated by the feeding of C. bipunctata.
- Published
- 2011
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42. Both nymphs and adults of the maize orange leafhopper induce galls on their host plant.
- Author
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Matsukura K, Matsumura M, and Tokuda M
- Abstract
The maize orange leafhopper, Cicadulina bipunctata, is a multivoltine insect that induces galls on various plants of the Poaceae. A previous study revealed that galls produced by this leafhopper were induced by dose-dependent stimulation on distant leaves from the feeding site, probably by chemical(s) injected from adults during feeding. In this paper, we examined the gall-inducing ability of C. bipunctata nymphs. The degree of gall induction gradually increased depending on the number of feeding nymphs and there were no significant differences from the positive control (feeding by five male adults) when seedlings were exposed to five or more nymphs. These results indicate that both adults and nymphs of C. bipunctata have the ability to induce galls on their host plants, a unique feature among gallinducing insects. This feature may be related to the free-living, multivoltine and polyphagous habits of C. bipunctata.
- Published
- 2010
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43. Host manipulation by the orange leafhopper Cicadulina bipunctata: gall induction on distant leaves by dose-dependent stimulation.
- Author
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Matsukura K, Matsumura M, and Tokuda M
- Subjects
- Animal Feed, Animals, Ecosystem, Female, Host-Parasite Interactions, Male, Oryza parasitology, Plant Diseases parasitology, Plant Leaves parasitology, Zea mays growth & development, Zea mays parasitology, Hemiptera physiology, Plant Tumors parasitology
- Abstract
The evolution of the gall-inducing ability in insects and the adaptive significance of the galling habit have been addressed by many studies. Cicadulina bipunctata, the maize orange leafhopper, is an ideal study organism for evaluating these topics because it can be mass-reared and it feeds on model plants such as rice (Oryza sativa) and maize (Zea mays). To reveal differences between gall inductions by C. bipunctata and other gall inducers, we conducted four experiments concerning (a) the relationship between the feeding site and gall-induction sites of C. bipunctata on maize, (b) the effects of leafhopper sex and density, (c) the effects of length of infestation on gall induction, and (d) the effects of continuous infestation. C. bipunctata did not induce galls on the leaves where it fed but induced galls on other leaves situated at more distal positions. The degree of gall induction was significantly correlated with infestation density and length. These results indicate that C. bipunctata induces galls in a dose-dependent manner on leaves distant from feeding sites, probably by injecting chemical(s) to the plant during feeding. We suggest that insect galls are induced by a chemical stimulus injected by gall inducers during feeding into the hosts.
- Published
- 2009
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44. Physiological response to low temperature in the freshwater apple snail, Pomacea canaliculata (Gastropoda: Ampullariidae).
- Author
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Matsukura K, Tsumuki H, Izumi Y, and Wada T
- Subjects
- Animals, Cold Temperature, Death, Environment, Environmental Exposure, Fresh Water, Gastrointestinal Tract pathology, Gastrointestinal Tract physiology, Gastropoda growth & development, Glucose metabolism, Glycerol metabolism, Glycogen metabolism, Seasons, Trypan Blue toxicity, Acclimatization physiology, Freezing, Gastropoda physiology
- Abstract
Cold hardiness of the freshwater apple snail, Pomacea canaliculata, varies seasonally. We investigated lethal factors and physiological changes arising from exposure of P. canaliculata to low temperatures. Snails did not survive freezing. The supercooling point of cold-acclimated (cold tolerant) snails (-6.6+/-0.8 degrees C) did not differ significantly from that of non-acclimated ones (-7.1+/-1.5 degrees C) under laboratory conditions. Furthermore, snails died even under more moderately low temperatures approaching 0 degrees C. These results indicate that indirect chilling injury is a factor in the death of P. canaliculata at low temperatures. Regardless of whether the snails were acclimated to low temperatures, all of the dead, and even some of the snails still alive at 0 degrees C, had injured mantles, indicating that the mantle may be the organ most susceptible to the effects of low temperatures. The concentration of glucose in the posterior chamber of the kidney and concentration of glycerol in the digestive gland were significantly higher in cold-acclimated snails than in non-acclimated ones, suggesting carbohydrate metabolic pathways are altered in snails during cold acclimation.
- Published
- 2009
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45. Changes in chemical components in the freshwater apple snail, Pomacea canaliculata (Gastropoda: Ampullariidae), in relation to the development of its cold hardiness.
- Author
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Matsukura K, Tsumuki H, Izumi Y, and Wada T
- Subjects
- Amino Acids analysis, Animals, Glucose analysis, Glycerol analysis, Seasons, Water analysis, Acclimatization physiology, Cold Temperature, Glycogen analysis, Lipids analysis, Snails chemistry
- Abstract
The apple snail, Pomacea canaliculata, is an invasive freshwater snail. It increases its cold hardiness before winter. However, the physiological mechanism of cold hardiness in molluscs is poorly understood, especially in freshwater molluscs. In this study, we examined the changes in low molecular weight compounds, glycogen and lipids, in the body of P. canaliculata in association with the development of cold hardiness. When snails without cold hardiness were experimentally cold-acclimated, the amount of glycerol, glutamine, and carnosine increased, while glycogen and phenylalanine decreased. Overwintering cold-tolerant snails collected from a drained paddy field in November also showed increased glycerol in their bodies with decreasing glycogen concentration, compared to summer snails collected from a submerged field. Water content also decreased during the cold acclimation, although the water loss was minimal. These results indicate that the freshwater snail, P. canaliculata enhances cold hardiness by accumulation of some kinds of low molecular weight compounds in its body as some insects do. However, the actual function of each low molecular compound is still unknown.
- Published
- 2008
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46. [Exposure to blood during midwifery operations--a questionnaire study].
- Author
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Kurumatani N, Matsukura K, Boku C, Kitauchi S, Sakaguchi R, Kamiya K, Kataoka M, Motoyama M, Miyata H, and Yoshioka N
- Subjects
- Accidents, Occupational, Female, Gloves, Protective, Humans, Infant, Newborn, Needlestick Injuries epidemiology, Pregnancy, Protective Clothing, Surveys and Questionnaires, Blood, Delivery, Obstetric, Midwifery, Occupational Exposure
- Abstract
A self-administered questionnaire was mailed to all midwives working in Nara Prefecture to investigate blood exposure events at delivery and to consider protective measures for the exposure. Out of the 203 midwives 193 responded to the questionnaire. The median number of deliveries in which the midwives had assisted within the past one year was 35 after excluding those who had not assisted in deliveries at all. The incidence of needle-stick injuries was estimated to be 86.2 per 100 persons within the past one year. The occurrence in the subgroup who had worked as midwife for less than 5 years was 2-3 times higher than that in those who worked for more than 5 years. Over 90% of the midwives had experiences of direct blood contact events to the skin while assisting in their 10 most recent deliveries. Blood contact events occurred in the finger-hand-arm area in 85% of the midwives, on the legs in 62%, in the face in 20% and in the eyes in 1%. Around 20% of the midwives had unintentionally sucked amniotic fluid when using a tracheal catheter on a newborn. The most common occasion where direct blood contact events occurred was while bathing an infant for removing blood and amniotic fluid. The midwives wore a disposal gown more often when assisting in labors of parturient women infected with blood-born infectious diseases than without the diseases, and similarly for wearing gloves when measuring blood loss and for usage of a mechanical device for sucking amniotic fluid in the tracheae of an infant. Based on the results obtained in this questionnaire study and our previous study about blood contact events observed in a delivery room, protective measures for midwives against exposure to blood at delivery are required and some ideas are presented.
- Published
- 1995
47. [Exposure to blood during midwifery procedures--blood contact events to midwives occurred in a delivery room].
- Author
-
Kurumatani N, Boku C, Matsukura K, Kitauchi S, Sakaguchi R, Kamiya K, Motoyama M, Kataoka M, Miyata H, and Yoshioka N
- Subjects
- Adolescent, Adult, Female, Humans, Infectious Disease Transmission, Patient-to-Professional prevention & control, Pregnancy, Protective Clothing, Blood, Delivery Rooms, Midwifery, Occupational Exposure
- Abstract
Midwives are often exposed to blood during delivery procedures. A study aimed at clarifying actual status of blood contact during midwifery procedures was performed. Observations in a delivery room were conducted to record blood contact events experienced by midwives from the time of episiotomy until 2 hour after expulsion of the placenta. All gloves used by midwives were collected and tested for holes. Blood contact was defined as any contact with blood of a parturition woman as recognized visually by an observer. During a one-month study period data was obtained from a total of 19 midwives (12 midwives and 7 student midwives) who assisted in 8 deliveries. All of the midwives wore gowns with long sleeves, gloves and caps but did not use eye protection or masks. None of the parturient women had Hepatitis B, Hepatitis C or acquired immunodeficiency syndrome. Deliveries caused widespread blood exposure to the midwives throughout the complete course. Protection from most of this exposure was provided by the gowns and gloves. However, direct blood contacts occurred to the fingers, hands or forearms in several midwives. These events were caused by partly because the midwives unintentionally performed procedures without gloves and partly because blood penetrated the gown and soaked to the skin. Direct blood contacts to the foot in two midwives and to the mouth in one also occurred. The overall perforation rate for gloves examined was 4 out of 154 (2.6%). Two gloves were broken during washing sharp instruments contaminated with blood, one was torn when wearing, and the remaining one appeared to have had a hole prior to use.(ABSTRACT TRUNCATED AT 250 WORDS)
- Published
- 1995
48. Studies on synthesis methods of bis(eugenolato)- zinc(II) and its basic properties(I).
- Author
-
Anzai M, Nakano T, Kikuchi H, Kawakami T, Matsukura K, Yoneyama M, and Kobari H
- Subjects
- Zinc Oxide-Eugenol Cement analysis, Zinc Oxide-Eugenol Cement chemical synthesis
- Published
- 1975
- Full Text
- View/download PDF
49. Influence of angiotensins (I, II & III) on prostaglandin production by minced rat renal medulla.
- Author
-
Satoh H, Matsukura K, Yamada R, and Satoh S
- Subjects
- Alprostadil, Angiotensin I pharmacology, Angiotensin II pharmacology, Angiotensin III pharmacology, Animals, In Vitro Techniques, Kidney Medulla drug effects, Male, Prostaglandins E biosynthesis, Rats, Rats, Inbred Strains, Thromboxane B2 biosynthesis, Angiotensins pharmacology, Kidney Medulla metabolism, Prostaglandins biosynthesis
- Abstract
Minced rat renal medulla was incubated for 30 min at 37 degrees C in the presence of angiotensin I, II or III (100 ng/ml) to determine the existence of a direct stimulating effect on prostaglandin (PG) production. PGE2, PGF2 alpha, 6-keto PGF1 alpha and Thromboxane B2 (TXB2) were determined by radioimmunoassay. For analysis of data variance, the results were separated according to whether the net output of PGE2 was above or below 1.5 ng PGE2 equivalent/mg tissue/30 min. Under low-output conditions, angiotensin I, II or III stimulated PGE2 production significantly (p less than 0.02) and tended to augment PGF2 alpha production, while under high-output conditions no effect on PGE2 or PGF2 alpha production was observed. Under either output condition, angiotensin I, II or III had no effect on 6-keto PGF1 alpha and TXB2.
- Published
- 1981
- Full Text
- View/download PDF
50. [General pharmacology of T-1982, a new cephamycin antibiotic].
- Author
-
Takai A, Hirai S, Watanabe I, Hiraiwa T, Abe N, Arai H, Omori M, Tanada K, Senda N, Hashiba K, Matsukura K, Takata K, and Okami H
- Subjects
- Animals, Cats, Central Nervous System drug effects, Electroencephalography, Female, Hemodynamics drug effects, Hemolysis drug effects, Male, Mice, Motor Activity drug effects, Muscle Contraction drug effects, Rats, Anti-Bacterial Agents pharmacology, Cephalosporins pharmacology, Cephamycins pharmacology
- Abstract
General pharmacological studies on T-1982 produced the following results. On central nervous system, subcutaneous injection of T-1982 at dose of 2,000 mg/kg hastened the onset of pentetrazole-induced tonic extensor in mice. T-1982 had no effect on spontaneous motor activity, pentobarbital hypnosis, body temperature or EEG in mice or rabbits, and also did not show motor incoordinate, anticonvulsive or analgesic activity in mice at intravenous doses of 250--1,000 mg/kg or subcutaneous doses of 500--2,000 mg/kg. On motor and sensory nervous systems, no effect of T-1982 was noted on spinal reflex, neuromuscular junction, conduction anesthesia or surface anesthesia in rats or rabbits. On respiratory, cardiovascular and autonomic nervous systems, T-1982 caused transient increase of respiratory rate, slight hypotension and transient increase of femoral blood flow in dogs at intravenous doses of 250--1,000 mg/kg. However, it caused a slight hypertensive tendency in rabbits. Heart rate and ECG in dogs or rabbits, blood pressure response to epinephrine, isoproterenol, acetylcholine or histamine in dogs, nictitating membrane in cats and pupil size in mice were not affected after intravenous injection of T-1982. No effect was found on isolated guinea pig atrium or rabbit descending aorta following T-1982 application. On renal function in rats, T-1982 caused an increase of PSP excretion but had no effect on urine volume or electrolytes excretion at intravenous doses of 250--1,000 mg/kg. T-1982 prolonged bleeding time in mice at intravenous doses of 500--1,000 mg/kg, but did not show hemolytic property and inhibitory activity on blood coagulation or platelet aggregation in vitro experiments. Spontaneous movement and tone of isolated stomach, ileum, colon, uterus, vas deferens or trachea and acetylcholine-, histamine-, nicotine- or barium chloride-induced contraction of ileum were not affected following T-1982 application. Intestinal propulsion of barium meal in mice, gastric secretion and carrageenin-induced edema in rats were not affected after intravenous injection of T-1982. T-1982 increased bile secretion in rats dose-dependently at intravenous doses of 31.3--125 mg/kg. The local irritative activity of T-1982 in rats was slightly milder than cefoxitin and moderately milder than cefmetazole after intradermal injection. In conclusion, these results suggest that T-1982 would not cause any adverse effects at its estimated clinical doses of 10--20 mg/kg (500--1,000 mg/man).
- Published
- 1982
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