Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99


Any time

2019 ( 2 )

2018 ( 13 )

2017 ( 10 )

2016 ( 16 )

Custom range...

Search Results: 1 - 10 of 1330 matches for " Yoshinori Miyazaki "
All listed articles are free for downloading (OA Articles)
Page 1 /1330
Display every page Item
Quantitative Assessment of the Effect of Nitric Oxide Synthase Inhibition on Tumor Vascular Activity Using Dynamic Contrast-Enhanced Computed Tomography  [PDF]
Kenya Murase, Yoshinori Kusakabe, Shohei Miyazaki
Open Journal of Medical Imaging (OJMI) , 2016, DOI: 10.4236/ojmi.2016.62005
Abstract: Purpose: The purpose of this study was to develop a method to quantitatively assess the effect of nitric oxide synthase (NOS) inhibition on tumor vascular activity using dynamic contrast-enhanced computed tomography (DCE-CT) and to investigate its usefulness using animal experiments. Mate-rials and Methods: The DCE-CT studies were performed in anesthetized Fisher rats bearing tumors using a 4-row multi-slice CT. The scanning started 4 s before a bolus injection of iodinated contrast agent (CA) (150 mgI/kg) from the tail vein using an automatic injector and lasted 60 s at 1-s in-tervals. The contrast enhancement (CE) images were generated by subtracting the CT images before and after the administration of CA. First, the DCE-CT studies were performed before and 15, 30, and 45 min after administration of N-nitro-L-arginine (L-NNA) (1, 3, and 10 mg/kg) or vehicle, and the relative CE values were calculated by normalizing the CE image at each time point by that obtained from the first DCE-CT study. Second, we investigated the case when L-arginine (L-ARG) (200 mg/kg) and L-NNA (1, 3, and 10 mg/kg) were administered after the first and second DCE-CT studies, respectively. Third, we investigated the case when L-NNA (1, 3, and 10 mg/kg) and L-ARG (200 mg/kg) were administered after the first and second DCE-CT studies, respectively. Finally, we investigated the case when L-NNA (1, 3, and 10 mg/kg) and L-ARG (200 mg/kg) were administered simultaneously after the first DCE-CT study. Results: The relative CE value significantly decreased after L-NNA administration in a dose-dependent manner (p-values = 0.0074 and <0.0001 for 0 vs. 3 mg/kg and 0 vs. 10 mg/kg, respectively, at 15 min, 0.0003 and <0.0001 for 0 vs. 3 mg/kg and 0 vs. 10 mg/kg, respectively, at 30 min, and 0.0367 and 0.0004 for 0 vs. 3 mg/kg and 0 vs. 10 mg/kg, respectively, at 45 min). When L-ARG was administered prior to the administration of 1 mg/kg L-NNA, the relative CE value at 45 min was significantly higher than that at 15 min. When L-ARG was administered after L-NNA administration, there was no significant difference between the relative CE values at 15 min and 45 min. These results suggest that when using L-NNA in combination with L-ARG, their effect on tumor vascular activity differs depending on the order of their administration. When L-NNA and L-ARG were administered simultaneously, there was a tendency for the relative CE value to be higher than that when only L-NNA was administered, at all injected doses of L-NNA. Conclusion: Our method using DCE-CT is useful for monitoring the effect
Atherogenic lipids profile relates to postprandial hyperglycemia and hyperinsulinemia due to whole body insulin resistance in prediabetic subjects  [PDF]
Yoshinori Miyazaki, Makoto Furugen, Hiroshi Akasaka, Shigeyuki Saitoh, Tetsuji Miura
Journal of Diabetes Mellitus (JDM) , 2012, DOI: 10.4236/jdm.2012.23044
Abstract: Backgrounds: Differences in serum lipids profiles in different type of glucose intolerance are unclear. Aims: To characterize lipid profiles in different type of glucose intolerance, and to assess relationships between serum lipids profile and disturbance of glucose metabolism in prediabetic subjects. Methods: Using the measurements in medical check-up with 75 goral glucose tolerance test (OGTT), total of 620 male subjects, who are not on medications for metabolic diseases or hypertension, were divided into normal fasting glucose and glucose tolerance (NFG/ NGT), isolated impaired fasting glucose (iIFG), isolated impaired glucose tolerance (iIGT) and combined IFG and IGT (IFG/IGT) based on results of the OGTT. Results: Age and body mass index (BMI) were similar in the four groups. Matsuda index (an index of whole body insulin sensitivity) was lower in iIFG, iIGT and IFG/IGT as compared with NFG/NGT. Plasma insulin excursion during the OGTT was significantly higher in IFG/IGT versus NFG/NGT. Serum triglyceride level (TG) and TG to HDL ratio (TG/HDL) were higher in IFG/IGT versus NFG/NGT. Matsuda index was positively correlated with HDL and was inversely correlated with TG, LDL, non-HDL, TG/ HDL and LDL to HDL ratio (LDL/HDL). Backward stepwise multiple regression analysis indicated that increases in BMI, plasma insulin level at 60 min (PI60) and plasma glucose level at 120 min in the OGTT were independently associated with increases in TG and TG/HDL. Increases in BMI and PI60 were related to an increase in non-HDL and LDL/HDL and a decrease in HDL. Conclusions: These results indicate that postprandial hyperglycemia and hyperinsulinemia based on advanced insulin resistance are closely related to lipid risk factors of atherosclerotic macrovascular disease in prediabetic subjects.
Visceral fat dominant distribution in male type 2 diabetic patients is closely related to hepatic insulin resistance, irrespective of body type
Yoshinori Miyazaki, Ralph A DeFronzo
Cardiovascular Diabetology , 2009, DOI: 10.1186/1475-2840-8-44
Abstract: Thirty-six type 2 diabetic male patients underwent a euglycemic insulin clamp (insulin infusion rate = 40 mU/m2·min) with 3-3H-glucose to measure insulin-mediated total body (primarily reflects muscle) glucose disposal (TGD) and suppression of endogenous (primarily reflects liver) glucose production (EGP) in response to a physiologic increase in plasma insulin concentration. Abdominal subcutaneous (SF) and intraabdominal visceral fat (VF) areas were quantitated with magnetic resonance imaging (MRI) at the level of L4–5.TGD and TGD divided by steady state plasma insulin concentration during the insulin clamp (TGD/SSPI) correlated inversely with body mass index (BMI), total fat mass (FM) measured by 3H2O, SF and VF areas, while VF/SF ratio displayed no significant relationship with TGD or TGD/SSPI. In contrast, EGP and the product of EGP and SSPI during the insulin clamp (an index hepatic insulin resistance) correlated positively with VF/SF ratio, but not with BMI, FM, VF or SF.We conclude that, independent of the individual's body type, visceral fat dominant accumulation as opposed to subcutaneous fat accumulation is associated with hepatic insulin resistance, whereas peripheral (muscle) insulin resistance is more closely related to general obesity (i.e. higher BMI and total FM, and increased abdominal SF and VF) in male patients with type 2 diabetes.Reduced insulin-mediated glucose disposal in muscle and impaired suppression of hepatic glucose production by insulin are common metabolic features of both obesity and type 2 diabetes mellitus (T2DM) [1]. A close association between obesity and T2DM is well established [2,3]. Many studies have documented that intraabdominal visceral fat is closely associated with insulin resistance in obese non-diabetic and T2DM subjects [4-13]. However, several studies have demonstrated that subcutaneous fat, not visceral fat, is the best predictor of insulin resistance in obese individuals [14-17]. The factors responsible for these inc
Development of a Molecular Marker to Identify a Candidate Line of Turmeric (Curcuma longa L.) with a High Curcumin Content  [PDF]
Hiroshi Hayakawa, Tetsuya Kobayashi, Yukio Minaniya, Katsura Ito, Akira Miyazaki, Tatsuya Fukuda, Yoshinori Yamamoto
American Journal of Plant Sciences (AJPS) , 2011, DOI: 10.4236/ajps.2011.21002
Abstract: Dried and fresh rhizomes of the spice turmeric (Curcuma longa L.) are well known in traditional medicine, and curcu- min is widely used in various geographic regions. Although there are differences in the amount of curcumin within this species, identification of the candidate line by rhizome is difficult because of the relative simplicity of its morphological characteristics. To accurately identify lines of C. longa with a high content of curcumin, we analysed several sequences of chloroplast DNA. First, to determine the appropriate outgroup taxa in which to conduct infras-pecific analyses of C. longa, we reconstructed the molecular phylogenetic tree of C. longa and its allied species. The results showed that C. aromatica and C. zedoaria are closely related to C. longa. Next, to develop a molecular marker for identifying lines of C. longa with a high content of curcumin, a network analysis using chloroplast microsatellite regions was performed. Results showed that a unique haplotype within C. longa corresponds to the high curcumin content line. Therefore, the chloroplast microsatellite regions used for the analysis allowed us to determine the lines of this species with high cur- cumin content.
Web application for recording learners’ mouse trajectories and retrieving their study logs for data analysis
Mitsumasa Zushi,Yoshinori Miyazaki,Ken Norizuki
Knowledge Management & E-Learning : an International Journal , 2012,
Abstract: With the accelerated implementation of e-learning systems in educational institutions, it has become possible to record learners’ study logs in recent years. It must be admitted that little research has been conducted upon the analysis of the study logs that are obtained. In addition, there is no software that traces the mouse movements of learners during their learning processes, which the authors believe would enable teachers to better understand their students’ behaviors. The objective of this study is to develop a Web application that records students’ study logs, including their mouse trajectories, and to devise an IR tool that can summarize such diversified data. The results of an experiment are also scrutinized to provide an analysis of the relationship between learners’ activities and their study logs.
Quantitative Assessment of Protective Effects of Antioxidant Agents against Drug-Induced Nephrotoxicity Using Dynamic Contrast-Enhanced Computed Tomography  [PDF]
Kenya Murase, Akihiro Kitamura, Atsushi Tachibana, Yoshinori Kusakabe, Risa Matsuura, Shohei Miyazaki
Open Journal of Medical Imaging (OJMI) , 2016, DOI: 10.4236/ojmi.2016.63006
Abstract: Purpose: The purpose of this study was to develop a method for quantifying the extent of renal dysfunction due to drug-induced nephrotoxicity using dynamic contrast-enhanced computed tomography (DCE-CT) and to investigate the protective effects of various antioxidant agents against cis-dichlorodiammineplatinum (cisplatin)-induced nephrotoxicity in rats using this method. Materials and Methods: The DCE-CT studies were performed in 8-week-old male Sprague-Dawley rats. The CT scanning started 4 s before a bolus intravenous injection of iodinated contrast agent (CA) (150 mgI/kg) from the tail vein using an automatic injector and lasted 90 s at 1-s intervals. The contrast clearance per unit renal volume (K1) was estimated from the DCE-CT data using the Patlak model. The renal volume (V) was calculated by manually delineating the kidney on the CT image. The contrast clearance of the entire kid-ney (K) was obtained by . First, to investigate the effect of CA itself, the DCE-CT studies were performed without injecting cisplatin 2, 4, and 7 days after the first DCE-CT study on day 0. Second, to investigate the effect of injected dose of cisplatin, the DCE-CT study was performed after the intraperitoneal (i.p.) injection of cisplatin (1.8 mg/kg) and was repeated every other day for one week. Finally, to investigate the protective effects of antioxidant agents [L-arginine (300 mg/kg), N-acetylcysteine (500 or 1000 mg/kg), methimazole (40 mg/kg), captopril (60 mg/kg), and taurine (750 mg/kg)], the DCE-CT studies were performed on days 0, 2, 4, and 7 after the i.p. injection of cisplatin (3.6 mg/kg). For comparison, the DCE-CT data were also acquired without injecting the antioxidant agents (CDDP group). Results: When cisplatin was not injected, there were no significant changes in the K value as compared to that on day 0 within the studied period. The K valuesignificantly (p < 0.05) decreased with increasing dose of cisplatin. Although some differences were observed in the extent of change in the K value normalized by that on day 0, depending on the antioxidant agents and their injected dose and schedule, the normalized K values on day 7 in the groups injected with the antioxidant agents were significantly higher than those in the CDDP group, suggesting that the antioxidant agents studied here had protective effects against cisplatin-induced nephrotoxicity in varying degrees. Conclusion: Our method appears useful for quantitatively evaluating the protective effects of antioxidant agents against cisplatin-induced nephrotoxicity and for investigating the optimal
Changes in Plant Species during Succession in a Sago Forest  [PDF]
Yoshimasa Kumekawa, Matheus Kilmaskossu, Makito Mori, Akira Miyazaki, Katsura Ito, Ryo Arakawa, Tatsuya Fukuda, Hubertus Matanubun, Yoshinori Yamamoto
American Journal of Plant Sciences (AJPS) , 2014, DOI: 10.4236/ajps.2014.524369
Abstract: The variation in solar environments during succession in sago forests is thought to affect the growth of many plant species. To clarify the pattern of plant colonization in sago forests at various successional stages, we constructed eleven 10 m × 10 m quadrats in different solar conditions in sago forests, measured and calculated the relative illumination intensity, collected all plant species in these quadrats, and used two chloroplast gene sequences—the rbcL gene of ferns and the trnL intron of angiosperms to molecularly identify them. The number of ferns increased while the number of herbaceous species decreased during the process of succession. Moreover, the number of woody species was not significantly correlated with the relative light intensity. Based on these results, it can be concluded that woody species colonized and grew at various successional stages but herbaceous species and ferns did the same in the early and late successional stages, respec-tively, in the sago forest.
A Comment on Reis  [PDF]
Kenji Miyazaki
Theoretical Economics Letters (TEL) , 2011, DOI: 10.4236/tel.2011.13019
Abstract: This note gives a counterexample on Reis [1]. Using a certain family of utility functions, this note not only gives a sharper representation than that of Reis but also demonstrates that interest rate inelastic money demand does not lead to superneutrality. This implies that superneutrality does not exist when uncerinty is introduced.
Incentives in Public and Privatized Firms under Incomplete Contracting Situations  [PDF]
Takeshi Miyazaki
Theoretical Economics Letters (TEL) , 2012, DOI: 10.4236/tel.2012.23059
Abstract: It is argued that incentives for employees in the public service agencies will necessarily be weak because of the multiple dimensions of products, multiple principals, incomplete contract, and socializing. Some empirical studies refer to incomplete contracting situations as part of the cause of the diminishing of the public sector. This work investigates the effects of privatization and ownership shares on incentive schemes for employees who work for public or privatized firms under incomplete contracting situations. Two main results are obtained. First, the incentive intensity of public firms decreases as the government has more ownership shares, and the social benefit declines. Second, privatized firms offer their employees higher-powered incentive contracts than do public firms.
Intoxica??o por chumbo e saúde infantil: a??es intersetoriais para o enfrentamento da quest?o
Padula, Niura Aparecida de Moura Ribeiro;Abreu, Maria Helena de;Miyazaki, Luís César Yoshinori;Tomita, Nilce Emy;,;
Cadernos de Saúde Pública , 2006, DOI: 10.1590/S0102-311X2006000100017
Abstract: an epidemiological survey was carried out by technicians of the state health secretary and the municipal health secretary of bauru, s?o paulo, brazil, due to excessive atmospheric lead emissions caused by a battery manufacturer. this survey included 853 children from 0 to 12 years old, in a 1,000-meter area from the polluting source, in bauru (2002). the blood lead levels of children in the exposed group were higher than those in the control group (p < 0.05). 314 children were found to have dosages equal or superior to 10μg/dl, the limit stipulated by centers for disease control and prevention. public services, universities, and volunteers developed some activities aiming at child diagnosis and treatment. the municipal health secretary coordinated remediation initiatives such as: scraping the superficial surface of streets, internal aspiration of houses with professional equipment, and washing and sealing tanks. through this work, the lead poisoning study and research group (gepiccb) shares an integrated, interdisciplinary, and interinstitutional action proposal.
Page 1 /1330
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.