Fukui-shi, Japan
Fukui-shi, Japan

Jin-ai University is a private university in Echizen, Fukui, Japan. Wikipedia.

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Islam M.R.,National Institute for Physiological science | Uramoto H.,Jin-ai University | Okada T.,National Institute for Physiological science | Sabirov R.Z.,National Institute for Physiological science | And 2 more authors.
American Journal of Physiology - Cell Physiology | Year: 2012

The maxi-anion channel plays a classically recognized role in controlling the membrane potential through the chloride conductance. It also has novel functions as a regulated pathway for the release of the anionic signaling molecules ATP and excitatory amino acids from cells subjected to osmotic perturbation, ischemia, or hypoxia. Because hemichannels formed by pannexins and connexins have been reported to mediate ATP release from a number of cell types, these hemichannels may represent the molecular correlate of the maxi-anion channel. Here, we found that L929 fibrosarcoma cells express functional maxi-anion channels which mediate a major portion of swelling-induced ATP release, and that ATP released via maxi-anion channels facilitates the regulatory volume decrease after osmotic swelling. Also, it was found that the cells express the mRNA for pannexin 1, pannexin 2, and connexin 43. Hypotonicity-induced ATP release was partially suppressed not only by known blockers of the maxi-anion channel but also by several blockers of pannexins including the pannexin 1-specific blocking peptide 10Panx1 and small interfering (si)RNA against pannexin 1 but not pannexin 2. The inhibitory effects of maxi-anion channel blockers and pannexin 1 antagonists were additive. In contrast, maxi-anion channel activity was not affected by pannexin 1 antagonists and siRNAs against pannexins 1 and 2. Although a connexin 43-specific blocking peptide, Gap27, slightly suppressed hypotonicity-induced ATP release, maxi-anion channel activity was not affected by Gap27 or connexin 43-specific siRNA. Thus, it is concluded that the maxi-anion channel is a molecular entity distinct from pannexin 1, pannexin 2, and connexin 43, and that the maxi-anion channel and the hemichannels constitute separate pathways for swelling-induced ATP release in L929 cells. © 2012 the American Physiological Society.

Uramoto H.,National Institute for Physiological science | Uramoto H.,Jin-ai University | Okada T.,National Institute for Physiological science | Okada Y.,National Institute for Physiological science
Cellular Physiology and Biochemistry | Year: 2012

Background: The cardiac isoform of the cystic fbrosis transmembrane conductance regulator (CFTR) was shown to be activated by β-adrenergic or purinergic stimulation and involved in cell volume regulation after osmotic swelling. Also, cardiac CFTR was reported to be essential in the mechanism by which ischemic preconditioning protects against ischemia/reperfusion(I/R)- induced injury of the heart. Here, we explored the possibility that activation of cardiac CFTR can provide protection against I/R-induced myocardial infarction, even after ischemic attack. Methods: The hearts of wild-type mice were subjected to 30- or 40-min left coronary artery occlusion followed by 2-h or 2-day reperfusion in vivo, and myocardial infarction was examined under a variety of conditions. Neonetal rat ventricular myocytes in primary culture were subjected to hypoxia/reoxygenation in vitro, and necrotic cell death was examined. Results: The infarct size was much greater in CFTR knockout mice than in wild-type mice. Intravenous infusion of a number of putative CFTR activators upon reperfusion prominently reduced the size of myocardial infarction in wild-type but not CFTR-defcient mice. This protective effect was abolished by co-administration of a CFTR inhibitor. CFTR activators ameliorated, in a manner sensitive to a CFTR inhibitor, release of myocardial-specifc creatine kinase isoenzyme to the serum in mice subjected to I/R in vivo. Necrotic death of cultured neonatal rat ventricular myocytes subjected to hypoxia/reoxygenation in vitro was ameliorated by CFTR activators or CFTR gene overexpression but aggravated by a CFTR inhibitor or CFTR gene silencing. Conclusion: It is concluded that activation of endogenous myocardial CFTR upon early reperfusion is involved in protection against necrotic myocardial injury induced by I/R in vivo and in vitro. Cardiac CFTR may serve as a target accessible even after ischemic attack for pharmacotherapeutic intervention in I/R-induced myocardial infarction. Copyright © 2012 S. Karger AG, Basel.

Ueno K.,University of Fukui | Takahashi T.,University of Fukui | Takahashi K.,University of Fukui | Mizukami K.,Jin-ai University | And 2 more authors.
Clinical Neurophysiology | Year: 2015

Objectives: Creativity, which presumably involves various connections within and across different neural networks, reportedly underpins the mental well-being of older adults. Multiscale entropy (MSE) can characterize the complexity inherent in EEG dynamics with multiple temporal scales. It can therefore provide useful insight into neural networks. Given that background, we sought to clarify the neurophysiological bases of creativity in healthy elderly subjects by assessing EEG complexity with MSE, with emphasis on assessment of neural networks. Methods: We recorded resting state EEG of 20 healthy elderly subjects. MSE was calculated for each subject for continuous 20-s epochs. Their relevance to individual creativity was examined concurrently with intellectual function. Results: Higher individual creativity was linked closely to increased EEG complexity across higher temporal scales, but no significant relation was found with intellectual function (IQ score). Conclusions: Considering the general "loss of complexity" theory of aging, our finding of increased EEG complexity in elderly people with heightened creativity supports the idea that creativity is associated with activated neural networks. Significance: Results reported here underscore the potential usefulness of MSE analysis for characterizing the neurophysiological bases of elderly people with heightened creativity. © 2014 International Federation of Clinical Neurophysiology.

Iki M.,Kinki University | Fujita Y.,Kinki University | Tamaki J.,Osaka Medical College | Kouda K.,Kinki University | And 6 more authors.
Osteoporosis International | Year: 2015

Summary: FRAX® is widely used to evaluate fracture risk of individuals in clinical settings. However, FRAX® prediction accuracy is not sufficient, and improvement is desired. Trabecular bone score, a bone microarchitecture index, may improve FRAX® prediction accuracy for major osteoporotic fractures in community-dwelling elderly Japanese men. Introduction: To improve fracture risk assessment in clinical settings, we evaluated whether the combination of FRAX® and Trabecular Bone Score (TBS) improves the prediction accuracy of major osteoporotic fractures (MOFs) in elderly Japanese men compared to FRAX® alone. Methods: Two thousand and twelve community-dwelling men aged ≥65 years completed the Fujiwara-kyo Osteoporosis Risk in Men (FORMEN) Baseline Study comprising lumbar spine (LS) and femoral neck areal bone mineral density (aBMD) measurements, and interviews regarding clinical risk factors required to estimate 10-year risk of MOF (hip, spine, distal forearm, and proximal humerus) using the Japanese version of FRAX® (v.3.8). TBS was calculated for the same vertebrae used for LS-aBMD with TBS iNsight software (v.2.1). MOFs that occurred during the follow-up period were identified by interviews or mail and telephone surveys. Prediction accuracy of a logistic model combining FRAX® score and TBS compared to FRAX® alone was evaluated by area under receiver-operating characteristic curves (AUCs), as well as category-free integrated discrimination improvement (IDI) and net reclassification improvement (NRI). Results: We identified 22 men with MOFs during 8140 person-years (PY) of follow-up among 1872 men; 67 men who suffered from fractures other than MOFs were excluded. Participants with MOFs had significantly lower TBS (p = 0.0015) and higher FRAX® scores (p = 0.0089) than those without. IDI and NRI showed significant improvements in reclassification accuracy using FRAX® plus TBS compared to FRAX® alone (IDI 0.006 (p = 0.0362), NRI 0.452 (p = 0.0351)), although no difference was observed in AUCs between the two. Conclusions: TBS may improve MOF prediction accuracy of FRAX® for community-dwelling elderly Japanese men. © 2015, International Osteoporosis Foundation and National Osteoporosis Foundation.

Iki M.,Kinki University | Dongmei N.,Kinki University | Tamaki J.,Kinki University | Sato Y.,Jin-ai University | And 3 more authors.
Osteoporosis International | Year: 2011

Summary: We analyzed 2,107 hip dual-energy X-ray absorptiometry (DXA) images from the Japanese Population-based Osteoporosis Study with the Hip Structure Analysis (HSA) program to obtain age-specific reference values of HSA indices for the Japanese female population. These references may help physicians accurately assess HSA results and aid researchers in making interracial comparisons of the indices. Introduction Hip geometry is expected to improve hip fracture risk assessment, which is usually assessed by bone mineral density (BMD) alone. We aimed to establish a reference database for Japanese women. Methods: We studied 2,107 Japanese women (15-79 years old) with no history of bone metabolism-related diseases from the Japanese Population-based Osteoporosis Study performed in 1996. Hip geometry was conducted on DXA images with the HSA program, which yielded data for cross-sectional area (CSA), subperiosteal diameter (PD), endocortical diameter (ED), mean cortical thickness (CT), section modulus (SM), and buckling ratio at the narrow neck (NN), intertrochanter (IT), and femoral shaft (FS) regions. Mean HSA indices were determined for each 5-year age group after adjustment for height and weight based on most recent Japanese population values. Results: Age-related changes in HSA indices were evident for the 50-54 year group in the NN and IT regions and for the 55-59 year group in the FS region; these changes increased with age thereafter. Age-related changes in CSA and CT were almost identical to that of BMD. Japanese subjects exhibited BMD and CT values similar to those reported for US non-Hispanic white women, but had 16-23% smaller SM values. CSA and CT were highly correlated with conventional BMD, whereas ED, SM, and PD showed lower correlations. Conclusions: Age-specific reference values of HSA indices for the Japanese female population were obtained. This database will form the foundation for accurate HSA result evaluation. © International Osteoporosis Foundation and National Osteoporosis Foundation 2010.

Tamaki J.,Kinki University | Iki M.,Kinki University | Kadowaki E.,Kinki University | Sato Y.,Jin-ai University | And 4 more authors.
Osteoporosis International | Year: 2011

We evaluated the predictive ability of FRAX® in a cohort of 815 Japanese women. The observed 10-year fracture rate did not differ significantly from that predicted by FRAX®. The predictive ability of FRAX® without femoral neck bone mineral density (BMD) was similar to that with femoral neck BMD. Introduction: We evaluated the ability of the Japanese version of FRAX®, a World Health Organization fracture risk assessment tool, to predict the 10-year probability of osteoporotic fracture. Methods: Self-reported major osteoporotic fracture (N=43) and hip fracture (N=4) events were ascertained in the 10-year follow-up survey of the Japanese Population-Based Osteoporosis Cohort Study. Participants were 815 women aged 40-74 years at the baseline survey. Receiver operating characteristic curve analysis compared FRAX® with multiple logistic models based on age, body weight, and femoral neck BMD. Results: The number of observed major osteoporotic or hip fracture events did not differ significantly from the number of events predicted by the FRAX® model (with or without BMD). The area under the curve (AUC) value for FRAX® with BMD for predicting major osteoporotic fractures was similar to that of a logistic model with age, body weight, and BMD (0.69 vs. 0.71, respectively; p=0.198); the AUC of FRAX® with BMD for predicting hip fractures was similar to that of a model based on age and BMD (0.88 vs. 0.89, respectively; p=0.164). The AUCs of FRAX® without BMD for predicting major osteoporotic and hip fractures were similar to those with BMD (0.69 vs. 0.67, respectively; p=0.121; 0.88 vs. 0.86, respectively; p=0.445). Conclusions: The Japanese version of FRAX® without BMD estimated the 10-year probability of osteoporotic fracture in this population with few clinical risk factors as similar to that of FRAX® with BMD. © 2011 International Osteoporosis Foundation and National Osteoporosis Foundation.

Iki M.,Kinki University | Tamaki J.,Kinki University | Fujita Y.,Kinki University | Kouda K.,Kinki University | And 7 more authors.
Osteoporosis International | Year: 2012

Summary: Recent animal studies have demonstrated that undercarboxylated osteocalcin upregulates insulin secretion via osteoblast-insulin signaling. However, it remains unclear whether such a pathway exists in humans. This study showed that serum undercarboxylated osteocalcin levels were inversely associated with fasting plasma glucose, hemoglobin A 1c, and homeostasis model assessment of insulin resistance (HOMA-IR) levels in community-dwelling elderly Japanese men. Introduction: Undercarboxylated osteocalcin (ucOC) was reported to increase insulin secretion and improve glucose tolerance via osteoblast-insulin signaling in animal-based studies. Whether this pathway also exists in humans is unknown. We aimed to clarify whether serum ucOC levels are associated with glycemic status and insulin resistance in the general Japanese population. Methods: We included 2,174 Japanese men (≥65 years) who were able to walk without aid from others and lived at home in four cities of Nara Prefecture. We excluded participants with a history of diseases or medications that affect bone metabolism, other than type 2 diabetes mellitus (T2DM). Fasting plasma glucose, glycated hemoglobin A 1c, and HOMA-IR levels were determined as outcome measures. Results: Of the 1,597 participants included in the analysis, both intact OC (iOC) and ucOC levels showed significant inverse correlations with all outcome measures, even after adjusting for potential confounders. Mean values of outcome measures showed a significant decreasing trend with higher quintiles of iOC or ucOC after adjusting for confounders. This trend remained significant for ucOC quintiles after further adjustment for iOC levels, but was not significant for iOC quintiles after adjusting for ucOC levels. These results were attenuated, but still apparent, after excluding participants receiving drug therapy for T2DM. Conclusions: Levels of ucOC, but not iOC, were inversely associated with glycemic index and insulin resistance in a population of Japanese men. These findings will need to be confirmed with longitudinal studies. © 2011 International Osteoporosis Foundation and National Osteoporosis Foundation.

Yamamoto T.,Kyoto University | Hara H.,Kyoto University | Tsuchiya K.,Kyoto University | Sakai S.,Kyoto University | And 6 more authors.
Infection and Immunity | Year: 2012

Among a number of laboratory strains of Listeria monocytogenes used in experimental infection, strain LO28 is highly capable of inducing robust beta interferon (IFN-β) production in infected macrophages. In this study, we investigated the molecular mechanism of the IFN-β-inducing ability of LO28 by comparing it with that of strain EGD, a low-IFN-β-inducing strain. It was found that LO28 secretes a large amount of IFN-β-inducing factor, which turned out to be cyclic di-AMP. The secretion of cyclic di-AMP was dependent on MdrT, a multidrug resistance transporter, and LO28 exhibited a very high level of mdrT expression. The introduction of a null mutation into mdrT abolished the ability of LO28 to induce IFN-β production. Examination of genes responsible for the regulation of mdrT expression revealed a spontaneous 188-bp deletion in tetR of LO28. By constructing recombinant strains of LO28 and EGD in which tetR from each strain was replaced, it was confirmed that the distinct ability of LO28 is attributable mostly to tetR mutation. We concluded that the strong IFN-β-inducing ability of LO28 is due to a genetic defect in tetR resulting in the overexpression of mdrT and a concomitant increase in the secretion of cyclic di-AMP through MdrT. © 2012, American Society for Microbiology.

Kouda K.,Kinki University | Fujita Y.,Kinki University | Sato Y.,Jin-ai University | Ohara K.,Kobe University | And 3 more authors.
Bone | Year: 2014

Epidemiologic studies have found that higher body weight is associated with better bone health. Body weight consists of both fat mass (FM) and lean soft tissue mass (LSTM). Previous studies have examined the effects of FM levels during childhood on bone health, with conflicting results. In the present study, we investigated the independent contributions of FM to bone mass in Japanese adolescents. Subjects were 235 adolescents aged 15-18. years old in August 2010 and in August 2013 from the Kitakata Kids Health Study in Japan. We obtained cross-sectional data on body composition as well as bone mineral density (BMD). Body composition and BMD were measured using a dual-energy X-ray absorptiometry scanner. We found moderate and positive relationships between FM index and LSTM index (males, r= 0.69; females, r= 0.44). To verify a potentially additive effect of FM on the variance of bone variables beyond LSTM, we assessed the association between FM index and bone variables after stratification by tertiles of the LSTM index. In the lowest tertile of the LSTM index, FM index was significantly (P<. 0.05) associated with both femoral neck BMD (males, β= 0.48; females, β= 0.33) and whole body BMC (males, β= 0.41; females, β= 0.25). On the other hand, we found no significant associations between FM index and bone variables in other tertiles of the LSTM index. These findings indicate that FM can influence how high bone mass is obtained among relatively thin adolescents, but not among those who are of normal weight or overweight. © 2014 Elsevier Inc.

Iki M.,Kinki University | Tamaki J.,Kinki University | Kadowaki E.,Kinki University | Sato Y.,Jin-ai University | And 5 more authors.
Journal of Bone and Mineral Research | Year: 2014

Bone strength is predominantly determined by bone density, but bone microarchitecture also plays an important role. We examined whether trabecular bone score (TBS) predicts the risk of vertebral fractures in a Japanese female cohort. Of 1950 randomly selected women aged 15 to 79 years, we analyzed data from 665 women aged 50 years and older, who completed the baseline study and at least one follow-up survey over 10 years, and who had no conditions affecting bone metabolism. Each survey included spinal imaging by dual-energy X-ray absorptiometry (DXA) for vertebral fracture assessment and spine areal bone mineral density (aBMD) measurement. TBS was obtained from spine DXA scans archived in the baseline study. Incident vertebral fracture was determined when vertebral height was reduced by 20% or more and satisfied McCloskey-Kanis criteria or Genant's grade 2 fracture at follow-up. Among eligible women (mean age 64.1 ± 8.1 years), 92 suffered incident vertebral fractures (16.7/103 person-years). These women were older with lower aBMD and TBS values relative to those without fractures. The unadjusted odds ratio of vertebral fractures for one standard deviation decrease in TBS was 1.98 (95% confidence interval [CI] 1.56, 2.51) and remained significant (1.64, 95% CI 1.25, 2.15) after adjusting for aBMD. The area under the receiver operating characteristic curve of TBS and aBMD combined was 0.700 for vertebral fracture prediction and was not significantly greater than that of aBMD alone (0.673). However, reclassification improvement measures indicated that TBS and aBMD combined significantly improved risk prediction accuracy compared with aBMD alone. Further inclusion of age and prevalent vertebral deformity in the model improved vertebral fracture prediction, and TBS remained significant in the model. Thus, lower TBS was associated with higher risk of vertebral fracture over 10 years independently of aBMD and clinical risk factors including prevalent vertebral deformity. TBS could effectively improve fracture risk assessment in clinical settings. © 2014 American Society for Bone and Mineral Research. © 2014 American Society for Bone and Mineral Research.

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