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Takata M, Murayama M, Fujimoto Y, Sasaki K, Shibahara T. Comparison of Nerve Repair Surgery for Inferior Alveolar Nerve. J Oral Maxillofac Surg 2014. [DOI: 10.1016/j.joms.2014.06.215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Fujimoto Y, Murayama M, Takata M, Sasaki K, Shibahara T. Studies on the sensory nerve action potentials of lingual nerve. J Oral Maxillofac Surg 2014. [DOI: 10.1016/j.joms.2014.06.209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Matsuyama H, Minami H, Kasahara H, Kato Y, Murayama M, Yumoto I. Pseudoalteromonas arabiensis sp. nov., a marine polysaccharide-producing bacterium. Int J Syst Evol Microbiol 2012; 63:1805-1809. [PMID: 22962336 DOI: 10.1099/ijs.0.043604-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A novel exopolysaccharide-producing bacterium, designated strain k53(T), was isolated from sediment from the Arabia Sea, Indian Ocean. The strain was Gram-negative, motile, strictly aerobic, oxidase-positive and catalase-positive, and required Na(+) for growth. Its major isoprenoid quinone was ubiquinone-8 (Q-8), and its cellular fatty acid profile mainly consisted of C16 : 1ω7c, C16 : 0 and C18 : 1ω7c. The DNA G+C content was 43 mol%. 16S rRNA gene sequence analysis suggested that strain k53(T) is a member of the genus Pseudoalteromonas. Strain k53(T) exhibited close phylogenetic affinity to Pseudoalteromonas lipolytica LMEB 39(T) (98.0% 16S rRNA gene sequence similarity) and Pseudoalteromonas donghaensis HJ51(T) (97.3 %).The DNA-DNA reassociation values between strain k53(T) and P. lipolytica JCM 15903(T) and P. donghaensis LMG 24469(T) were 17 % and 12 %, respectively. Owing to the significant differences in phenotypic and chemotaxonomic characteristics, and phylogenetic analysis based on the 16S rRNA gene sequence and DNA-DNA relatedness data, the isolate merits classification as a representative of a novel species, for which the name Pseudoalteromonas arabiensis is proposed. The type strain of this species is k53(T) ( = JCM 17292(T) = NCIMB 14688(T)).
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Wu CH, Reynolds WT, Murayama M. A software tool for automatic analysis of selected area diffraction patterns within Digital Micrograph™. Ultramicroscopy 2011; 112:10-4. [PMID: 22079497 DOI: 10.1016/j.ultramic.2011.09.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2011] [Revised: 09/16/2011] [Accepted: 09/21/2011] [Indexed: 11/16/2022]
Abstract
A software package "SADP Tools" is developed as a complementary diffraction pattern analysis tool. The core program, called AutoSADP, is designed to facilitate automated measurements of d-spacing and interplaner angles from TEM selected area diffraction patterns (SADPs) of single crystals. The software uses iterative cross correlations to locate the forward scattered beam position and to find the coordinates of the diffraction spots. The newly developed algorithm is suitable for fully automated analysis and it works well with asymmetric diffraction patterns, off-zone axis patterns, patterns with streaks, and noisy patterns such as Fast Fourier transforms of high-resolution images. The AutoSADP tool runs as a macro for the Digital Micrograph program and can determine d-spacing values and interplanar angles based on the pixel ratio with an accuracy of better than about 2%.
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Murayama M, Maeda Y, Goldsmith CE, Coulter WA, Masons C, Millar BC, Matsuda M, Moore JE. Molecular characterisation of the quinolone resistance-determining region (QRDR) of the parC gene locus in viridans-group streptococci. Br J Biomed Sci 2011; 68:109-11. [PMID: 21950200 DOI: 10.1080/09674845.2011.11730335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Forty-eight isolates of viridans-group streptococci (VGS) from adults and children in the community are examined for their resistance to ciprofloxacin phenotypically by determination of the minimum inhibitory concentration (MIC). In addition, the parC gene locus is amplified and sequenced in all isolates and mutations noted. Overall, 44 VGS organisms were found to be susceptible to ciprofloxacin by the broth microdilution method, and the remaining four strains had intermediate susceptibility. Reduced MICs were observed with intermediate strains when reserpine was added to the broth, inhibiting any efflux activity. Overall, the effect of adding reserpine to the broth medium was to add one doubling dilution to the MIC in the case of Streptococcus mitis, S. oralis and S. salivarius, as well as to increase the MIC by two doubling dilutions in two of the three S. parasanguinis isolates. Amino acid sequence analysis of the quinolone resistance-determining region (QRDR) of the parC gene locus showed good correlation to the phenotypic resistance to ciprofloxacin, where no confirmed mutation conferring quinolone resistance was found. Eleven amino acid positions showed discordance with S. pneumoniae R6 and eight (S52, F55, S58, N91, E135, K137, F141 and S167) were common in the VGS species examined. In addition, minor substitutions were found at three positions (D51, T54 and V86). In conclusion, this study demonstrates the low occurrence of ciprofloxacin resistance in a population of VGS isolated from the community. In addition, several silent mutations were noted in VGS organisms without any increase in MIC against ciprofloxacin.
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Nosaka S, Murayama M, Morita K, Katsuda K. [Pleomorphic carcinoma of the lung; report of a case]. KYOBU GEKA. THE JAPANESE JOURNAL OF THORACIC SURGERY 2011; 64:426-429. [PMID: 21591449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
A 83-year-old male was referred to our hospital for further examination of abnormal shadow on chest radiography. Chest computed tomography (CT) showed a tumor mass in his right lung. Bronchoscopy brushing cytology revealed non-small cell lung carcinoma and right middle lobectomy was performed. Histological findings showed large cell carcinoma comprised of spindle cell component, finally diagnosing as pleomorphic carcinoma of the lung. Although he was diagnosed as pT2N0M0 (stage IA) after the operation, massive liver metastasis was found 7 months later. We report this case with references to the literatures on pleomorphic carcinoma of the lung.
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Murayama M, Sekizuka T, Tazumi A, Moore JE, Millar BC, Matsuda M. Molecular analysis and characterisation of the full-length flagellin C gene (flaC) from Campylobacter lari. Br J Biomed Sci 2011; 68:11-8. [PMID: 21473256 DOI: 10.1080/09674845.2011.11732835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
A degenerate polymerase chain reaction (PCR) primer pair (f-ClflaC/r-ClflaC) was constructed in silico to amplify flaC and its adjacent genetic loci from Campylobacter lari isolates. Approximately 1.45 kbp amplicons, including the sequences encoding the flaC structural gene of 750 bp, putative promoter, rho-independent intrinsic terminator regions and partial sequences of two putative open reading frames (ORFs), immediately upstream and downstream of the gene, were identified in 16 C. lari isolates (four urease-negative [UN] C. lari; 12 urease-positive thermophilic campylobacters [UPTC)]). All 16 flaC structural genes commenced with an ATG start codon and terminated with a TAA stop codon and probable ribosome-binding sites were identified in all 16 isolates. These probably indicate a monocistronic operon structure for the flaC gene in C. lari isolates. In addition, the putative flaC gene ORFs were deduced to be similar in 747 bp among all 26 thermophilic Campylobacter isolates examined, resulting in a similar calculated molecular weight of approximately 26.6-26.9 kDa. The flaC from C. lari was different from the flaA-like sequence and the shorter flaA of UPTC isolates found previously. Reverse transcription PCR and Northern blot hybridisation analyses identified flaC transcription in C. lari cells. The transcription initiation site for the flaC gene was also determined by primer extension analysis. A dendrogram constructed, based on the nucleotide sequence information of flaC from 17 C. lari isolates, demonstrated that the C. lari isolates were genetically variable and formed two minor clusters for UN C. lari and UPTC.
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Maeda Y, Murayama M, Goldsmith CE, Coulter WA, Mason C, Millar BC, Dooley JSG, Lowery CJ, Matsuda M, Rendall JC, Elborn JS, Moore JE. Molecular characterization and phylogenetic analysis of quinolone resistance-determining regions (QRDRs) of gyrA, gyrB, parC and parE gene loci in viridans group streptococci isolated from adult patients with cystic fibrosis. J Antimicrob Chemother 2010; 66:476-86. [DOI: 10.1093/jac/dkq485] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Nosaka S, Murayama M, Beppu T, Katsuda K, Nakao M. [Pleomorphic carcinoma of the lung with idiopathic interstitial pneumonia; report of a case]. KYOBU GEKA. THE JAPANESE JOURNAL OF THORACIC SURGERY 2009; 62:843-846. [PMID: 19670793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
A 69-year-old man was referred to our hospital for further examination of the abnormal shadow on chest radiography. Chest computed tomography (CT) showed a tumor mass, 4 cm in size, in his right lung (S6) and interstitial pneumonia in the surrounding lung parenchyma Bronchoscopic brushing cytology revealed squamous cell carcinoma cells. Right lower and middle lobectomy was performed due to the metastasis to interlober lymph node. Histological findings showed squamous cell carcinoma comprised of spindle cell component, and there were also fibroblastic foci and fibroid thickness in the interstitium. Therefore he was diagnosed as pleomorphic carcinoma and usual interstitial pneumonia (UIP). About 7 months after the operation, the patient died of mainly multiple bone metastases. Pleomorphic carcinoma with UIP is very rare, so we report this case with references to the literatures.
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Nagashima J, Musha H, So T, Kunishima T, Nobuoka S, Murayama M. Effect of angiotensin-converting enzyme gene polymorphism on left ventricular remodeling after anteroseptal infarction. Clin Cardiol 2009; 22:587-90. [PMID: 10486698 PMCID: PMC6656168 DOI: 10.1002/clc.4960220909] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
BACKGROUND AND HYPOTHESIS Genetic influence on cardiac remodeling is uncertain. The purpose of this study is to determine the effects of polymorphism of the angiotensin-converting enzyme (ACE) gene on cardiac remodeling after myocardial infarction. METHODS The subjects were 43 patients with old anteroseptal myocardial infarction. Based on the polymorphism of the ACE gene, they were classified into a deletion group of 25 patients (D/D genotype in 4 and D/I genotype in 21) and an insertion group of 18 patients (all I/I genotype). Echocardiograms were used to determine left ventricular end-diastolic and end-systolic diameters, interventricular septal and posterior wall thicknesses, left ventricular mass, left atrial diameter, and left ventricular ejection fraction. Blood concentrations of atrial and brain natriuretic peptide were also measured. RESULTS Left ventricular end-systolic and end-diastolic dimensions, left ventricular mass, and levels of both atrial and brain natriuretic peptide were significantly higher in the deletion group. In contrast, septal thickness, posterior wall thickness, and ejection fraction showed no differences between the two groups. CONCLUSIONS In patients with old anteroseptal infarction, ACE gene polymorphism of the D/D and D/I genotypes has a stronger influence on left ventricular remodeling than polymorphism of the I/I genotype.
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Nagashima J, Musha H, Takada H, Awaya T, Oba H, Mori N, Ohmiya K, Nobuoka S, Murayama M. Influence of angiotensin-converting enzyme gene polymorphism on development of athlete's heart. Clin Cardiol 2009; 23:621-4. [PMID: 10941550 PMCID: PMC6655082 DOI: 10.1002/clc.4960230814] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND AND HYPOTHESIS Genetic influence on development of athlete's heart is uncertain. This study investigated whether angiotensin-converting enzyme (ACE) gene polymorphism influenced development of athlete's heart. METHODS Forty-three participants in a 100-km ultramarathon were classified on the basis of ACE gene polymorphism into a deletion group (n = 26) and an insertion group (n = 17). Echocardiograms were recorded to determine left ventricular end-diastolic and end-systolic diameters, interventricular septal thickness, left ventricular posterior wall thickness, left ventricular mass, and ejection fraction. RESULTS Left ventricular end-diastolic diameter (65.5 +/- 4.0 mm) and left ventricular mass (369.5 +/- 73.9 g) were significantly larger in the subjects with deletion than in those with insertion (57.4 +/- 4.2 mm, 306.5 +/- 93.7 g). However, no significant differences in the other parameters were noted. CONCLUSIONS In long-distance runners, ACE gene polymorphism of the D/D and D/I genotypes has a stronger influence on left ventricular hypertrophy than polymorphism of the I/I genotype.
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Tanabe K, Osada N, Suzuki N, Nakayama M, Yokoyama Y, Yamamoto A, Oya M, Murabayashi T, Yamamoto M, Omiya K, Itoh H, Murayama M. Erythrocyte magnesium and prostaglandin dynamics in chronic sleep deprivation. Clin Cardiol 2009; 20:265-8. [PMID: 9068914 PMCID: PMC6655760 DOI: 10.1002/clc.4960200315] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
BACKGROUND AND HYPOTHESIS The mechanism of sudden cardiac death occurring in patients with chronic fatigue is controversial. This study was designed to define a hypothesis that coronary arterial spasm and thrombus formation can occur during chronic fatigue. METHODS For evaluating the feasibility of coronary arterial spasm, erythrocyte magnesium (Mg) was measured. Blood coagulability was evaluated by the change of prostaglandin concentration. Subjects included 16 healthy male volunteers (mean age 21.6 +/- 2.5 years). Test conditions were as follows: (A) control state: a day following a night of good sleep; (B) temporary sleep deprivation: a day preceded by < 3 h of sleep; (C) chronic sleep deprivation: a day preceded by a month during which sleep lasted < 60% of that in condition (A) above. The erythrocyte Mg concentration was measured by the atomic absorption method. The plasma concentration of thromboxane B2 and 6-keto-prostaglandin F1 alpha were measured in eight subjects by radioimmunoassay method. RESULTS (1) Mean erythrocyte Mg concentration was significantly less in chronic sleep deprivation (1.1 +/- 0.4 mg/dl) than in the control state (1.8 +/- 0.4 mg/dl, p < 0.01) or in temporary sleep deprivation (1.6 +/- 0.4, p < 0.01). (2) The level of thromboxane B2 was significantly higher during chronic sleep deprivation than under control conditions (104.4 +/- 78.0 vs. 20.4 +/- 9.0 pg/ml, p < 0.05). (3) There were no significant intergroup differences in 6-keto-prostaglandin F1 alpha level. CONCLUSION These findings could support the hypothesis that coronary arterial spasm and thrombus formation occur in chronic sleep deprivation.
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Takeuchi Y, Uetsuka K, Murayama M, Kikuta F, Takashima A, Doi K, Nakayama H. Complementary Distributions of Amyloid-β and Neprilysin in the Brains of Dogs and Cats. Vet Pathol 2008; 45:455-66. [DOI: 10.1354/vp.45-4-455] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Neprilysin is an amyloid-β-degrading enzyme localized in the brain parenchyma. The involvement of neprilysin in the pathogenesis of Alzheimer's disease has recently received much attention. We examined the localization of neprilysin and amyloid-β, as well as the activity of neprilysin, in the brains of dogs and cats of various ages to clarify the relationship between neprilysin activity and amyloid-β deposition. The distribution of neprilysin was almost identical in dogs and cats, being high in the striatum, globus pallidus, and substantia nigra, but very low in the cerebral cortex. The white matter and hippocampus were negative. Neprilysin activity in the brain regions in dogs and cats was ranked from high to low as follows: thalamus/striatum > cerebral cortex > hippocampus > white matter. Amyloid-β deposition was first detected at 7 and 10 years of age in dogs and cats, respectively, and both the quantity and frequency of deposition increased with age. In both species, amyloid-β deposition appeared in the cerebral cortex and the hippocampus. In summary, the localization of neprilysin and neprilysin activity, and that of amyloid-β, were complementary in the brains of dogs and cats.
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Nosaka S, Murayama M, Beppu T, Katsuda K, Nakao M, Enomoto M. [Pleomorphic carcinoma of the lung; report of a case]. KYOBU GEKA. THE JAPANESE JOURNAL OF THORACIC SURGERY 2008; 61:512-515. [PMID: 18536305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
A 66-year-old female complained of cough, and was referred to our hospital. Chest radiography and computed tomography (CT) showed a tumor mass near the right hilum and atelectasis of the middle lobe. Bronchoscopy revealed a whitish polypoid tumor obstructing the middle lobe bronchus. Histology by punch biopsy suggested adenocarcinoma Right upper and middle lobectomy was performed, due to the direct invasion of the tumor from the middle lobe to the upper lobe. Histological findings showed adenocarcinoma comprised of spindle cell component, finally diagnosing as pleomorphic carcinoma of the lung. After the operation, systemic chemotherapy, including paclitaxel and carboplatin was performed. About 42 months after operation, the patient died of multiple brain metastases.
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Sahara N, Maeda S, Yoshiike Y, Mizoroki T, Yamashita S, Murayama M, Park JM, Saito Y, Murayama S, Takashima A. Molecular chaperone-mediated tau protein metabolism counteracts the formation of granular tau oligomers in human brain. J Neurosci Res 2008; 85:3098-108. [PMID: 17628496 DOI: 10.1002/jnr.21417] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Intracellular accumulation of filamentous tau proteins is a defining feature of neurodegenerative diseases termed tauopathies. The pathogenesis of tauopathies remains largely unknown. Molecular chaperones such as heat shock proteins (HSPs), however, have been implicated in tauopathies as well as in other neurodegenerative diseases characterized by the accumulation of insoluble protein aggregates. To search for in vivo evidence of chaperone-related tau protein metabolism, we analyzed human brains with varying degrees of neurofibrillary tangle (NFT) pathology, as defined by Braak NFT staging. Quantitative analysis of soluble protein levels revealed significant positive correlations between tau and Hsp90, Hsp40, Hsp27, alpha-crystallin, and CHIP. An inverse correlation was observed between the levels of HSPs in each specimen and the levels of granular tau oligomers, the latter of which were isolated from brain as intermediates of tau filaments. We speculate that HSPs function as regulators of soluble tau protein levels, and, once the capacity of this chaperone system is saturated, granular tau oligomers form virtually unabated. This is expressed pathologically as an early sign of NFT formation. The molecular basis of chaperone-mediated protection against neurodegeneration might lead to the development of therapeutics for tauopathies. (c) 2007 Wiley-Liss, Inc.
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Hirono T, Yeh EC, Lin W, Sone H, Mishima T, Soh W, Hashimoto Y, Matsubayashi O, Aoike K, Ito H, Kinoshita M, Murayama M, Song SR, Ma KF, Hung JH, Wang CY, Tsai YB, Kondo T, Nishimura M, Moriya S, Tanaka T, Fujiki T, Maeda L, Muraki H, Kuramoto T, Sugiyama K, Sugawara T. Nondestructive continuous physical property measurements of core samples recovered from hole B, Taiwan Chelungpu-Fault Drilling Project. ACTA ACUST UNITED AC 2007. [DOI: 10.1029/2006jb004738] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Nagashima J, Musha H, Takada H, Murayama M. Left ventricular chamber size predicts the race time of Japanese participants in a 100 km ultramarathon. Br J Sports Med 2006; 40:331-3; discussion 333. [PMID: 16556788 PMCID: PMC2577533 DOI: 10.1136/bjsm.2005.022673] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVE As a subanalysis of an echocardiographic study performed on 291 Japanese participants in a 100 km ultramarathon, to estimate predictors of race time. METHODS A total of 247 male participants in a 100 km ultramarathon (age 20-73 years) were examined by echocardiography. Correlations between age, body surface area, monthly running distance, or echocardiographic variables and the race time were examined. RESULTS According to simple regression analysis, age (r = 0.299, p < 0.0001), monthly running distance (r = -0.388, p < 0.0001), left ventricular end diastolic diameter (r = -0.300, p < 0.0001), and left ventricular end systolic diameter (r = -0.325, p < 0.0001) correlated significantly with the race time. When multiple regression analysis was performed, age (f = 2.364), monthly running distance (f = -0.113), and left ventricular end systolic diameter (f = -2.361) remained significant predictors of the race time. CONCLUSION Left ventricular diameter predicts the race time for a 100 km ultramarathon, in addition to age and amount of training.
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Cui D, Yoshiike Y, Park J, Jin Y, Murayama M, Planel E, Tatebayashi Y, Takashima A. P3-245 Participation of GSK-3beta in neurodegeneration. Neurobiol Aging 2004. [DOI: 10.1016/s0197-4580(04)81395-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Yokota T, Murayama M, Howe JM. In situ transmission-electron-microscopy investigation of melting in submicron Al-Si alloy particles under electron-beam irradiation. PHYSICAL REVIEW LETTERS 2003; 91:265504. [PMID: 14754065 DOI: 10.1103/physrevlett.91.265504] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2003] [Indexed: 05/24/2023]
Abstract
In situ heating and electron-beam irradiation in the transmission electron microscope were performed to study melting of submicron Al-11.6 at. % Si particles supported on a C thin film. It was found that electron irradiation could be used to melt the particles, even when the hot-stage sample holder was kept at a much lower temperature ( approximately 125 degrees C) than the initial melting point of the particles. Comparison between the experimentally observed melting behavior and analytical calculations indicate that melting of the submicron Al-Si particles under electron-beam irradiation is caused by a temperature rise due to electron thermal spikes in the particles and poor thermal conduction away from the particles. These results have important implications in transmission electron microscopy studies of nanoparticles supported on thin films or poorly conducting substrates.
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Murayama M, Howe JM, Hidaka H, Takaki S. Atomic-level observation of disclination dipoles in mechanically milled, nanocrystalline Fe. Science 2002; 295:2433-5. [PMID: 11923534 DOI: 10.1126/science.1067430] [Citation(s) in RCA: 209] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Plastic deformation of materials occurs by the motion of defects known as dislocations and disclinations. High-resolution transmission electron microscopy was used to directly reveal the individual dislocations that constitute partial disclination dipoles in nanocrystalline, body-centered cubic iron that had undergone severe plastic deformation by mechanical milling. The mechanisms by which the formation and migration of such partial disclination dipoles during deformation allow crystalline solids to fragment and rotate at the nanometer level are described. Such rearrangements are important basic phenomena that occur during material deformation, and hence, they may be critical in the formation of nanocrystalline metals by mechanical milling and other deformation processes.
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Sun X, Sato S, Murayama O, Murayama M, Park JM, Yamaguchi H, Takashima A. Lithium inhibits amyloid secretion in COS7 cells transfected with amyloid precursor protein C100. Neurosci Lett 2002; 321:61-4. [PMID: 11872257 DOI: 10.1016/s0304-3940(01)02583-6] [Citation(s) in RCA: 127] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
To examine the regulation of amyloid secretion in more detail, Abeta sandwich ELISAs with high sensitivity and specificity were developed. Using this technique, we measured Abeta secreted from COS7 cells transiently transfected with APP C100 in the presence of LiCl, a potent glycogen synthase kinase (GSK)-3beta inhibitor. We found that both Abetax-40 and Abetax-42 secretion were reduced by LiCl treatment in a dose-dependent manner. Diminished amyloid secretion was associated with GSK-3beta activity. These results suggest that GSK-3beta might function as a possible mediator for regulating both amyloid deposition and tau pathology in Alzheimer's disease (AD), and that lithium should be re-evaluated as a candidate reagent for preventing AD pathology.
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Oguri K, Itou M, Hirano S, Hisamitsu T, Sakai S, Murayama M, Kitazato H, Koizumi Y, Fukui M, Taira A. Environmental characteristics of water, sediments and microbial activities at Lake Kalike, Kamikoshiki Island, Kagoshima Prefecture: Toward an understanding of anoxic ocean. ACTA ACUST UNITED AC 2002. [DOI: 10.5575/geosoc.108.12_xxiii] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Tanemura K, Akagi T, Murayama M, Kikuchi N, Murayama O, Hashikawa T, Yoshiike Y, Park JM, Matsuda K, Nakao S, Sun X, Sato S, Yamaguchi H, Takashima A. Formation of filamentous tau aggregations in transgenic mice expressing V337M human tau. Neurobiol Dis 2001; 8:1036-45. [PMID: 11741399 DOI: 10.1006/nbdi.2001.0439] [Citation(s) in RCA: 106] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Formation of neurofibrillary tangles (NFTs) is the most common feature in several neurodegenerative diseases, including Alzheimer's disease (AD). Here we report the formation of filamentous tau aggregations having a beta-sheet structure in transgenic mice expressing mutant human tau. These mice contain a tau gene with a mutation of the frontotemporal dementia parkinsonism (FTDP-17) type, in which valine is substituted with methionine residue 337. The aggregation of tau in these transgenic mice satisfies all histological criteria used to identify NFTs common to human neurodegenerative diseases. These mice, therefore, provide a preclinical model for the testing of therapeutic drugs for the treatment of neurodegenerative disorders that exhibit NFTs.
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Abstract
Telemedicine has previously been defined as "live two-way interactive video communication between a physician and a patient and/or another physician, where all participants are able to see and hear one another much like a face to face encounter." This concept has gained recent notoriety because of the great advances in telecommunications and the potential future increased cost-effectiveness associated with its utilization. We have developed a telementoring deployment protocol that can be effectively used to introduce a student to telementoring processes. The strict protocol uses military commands to facilitate smooth information transfer. The use of a concept called tactical information deployment provides the surgeon with rapid access to reference information in the operating suite. Multimedia interactive CD-ROMs, with digitized movie clips, illustrations, sound bits, and the latest academic review of the literature arm the surgeon with a database that establishes an unprecedented clinical adaptive capability (CAC). The availability of this information is invaluable to surgeons in their initial advanced laparoscopic procedural efforts. Telementoring simulator opportunities are included to acclimate the participant to the process. If the process seems comprehensive, it is meant to be. This is a high-risk situation, and a patient's welfare is on the line. If this concept is to reach its maximal healthcare delivery potential, responsible and academically credible training programs should be established with directional guidelines.
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Matsushita S, Muramatsu T, Murayama M, Nakane J, Higuchi S. Alcoholism, ALDH2*2 allele and the A1 allele of the dopamine D2 receptor gene: an association study. Psychiatry Res 2001; 104:19-26. [PMID: 11600186 DOI: 10.1016/s0165-1781(01)00290-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The inactive form of aldehyde dehydrogenase-2 (ALDH2) is regarded as a protective factor against the development of alcoholism, and alcoholics with inactive ALDH2 are considered to be relatively homogeneous. This examination of a possible allelic association of the dopamine D2 receptor (DRD2) gene TaqI A polymorphism failed to detect significant differences between 583 Japanese alcoholics and 295 unrelated Japanese controls, or between alcoholic subjects with different ALDH2 genotypes. Despite the significantly higher frequency of the DRD2 A1 allele in the 207 alcoholics with inactive ALDH2 than in the 376 alcoholics with active ALDH2, multiple logistic regression analysis (controlled for the ALDH2 genotype) revealed no association between the TaqI A polymorphism and alcoholism. Nor did the frequency of the DRD2 TaqI A polymorphism differ in alcoholic subjects grouped by several pertinent clinical characteristics, including severity of alcoholism. Although there remains a possibility that the DRD2 TaqI A polymorphism plays some role in modifying the phenotype of the disease, these results suggest that neither the A1 allele nor the homozygous A1 genotype is associated with alcoholism.
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