Nakazawa A.,Ryotokuji University |
Nakamura K.,Niigata University |
Kitamura K.,Niigata University |
Yoshizawa Y.,Niigata Council of Institutions for the Elderly
Environmental Health and Preventive Medicine | Year: 2013
Background: The purpose of this study is to assess the association between body mass index (BMI) and mortality among nursing home residents in Japan. Methods: A one-year prospective cohort study was conducted with 8,510 elderly individuals across 140 nursing homes. Baseline measurements included age, sex, height, weight, BMI, activities of daily living (ADL) (Barthel Index), and degree of dementia. Information regarding dates of discharge and mortality were also obtained to calculate person-years. Cox's proportional hazards model was used to estimate hazard ratios. Results: Mean age and BMI were 84.3 [standard deviation (SD) 8.1] years and 20.6 (SD 3.8) kg/m2, respectively. Hazard ratios of mortality adjusted for sex, age, ADL, degree of dementia, and type of home were 2.4 [95 % confidence interval (CI): 1.9-3.1] for the 1st quintile of BMI (<17.3 kg/m2), 1.7 (95 % CI: 1.3-2.3) for the 2nd quintile (17.3-19.2 kg/m2), 1.5 (95 % CI: 1.2-2.0) for the 3rd quintile (19.3-21.1 kg/m2), and 1.2 (95 % CI: 0.9-1.6) for the 4th quintile (21.2-23.5 kg/m2) (P for trend <0.001), compared with the reference 5th quintile (23.6≤ kg/m2). Conclusions: There was a clear inverse dose-dependent relationship between BMI and mortality. Future studies should be conducted to determine the effects of nutritional intervention on mortality in institutionalized elderly adults. © 2013 The Japanese Society for Hygiene.
Otani S.,Ryotokuji University |
Otani S.,Juntendo University |
Bai J.,Juntendo University |
Blot K.,University Paris - Sud
Neuroscience Bulletin | Year: 2015
The prefrontal cortex (PFC) is thought to store the traces for a type of long-term memory — the abstract memory that determines the temporal structure of behavior often termed a “rule” or “strategy”. Long-term synaptic plasticity might serve as an underlying cellular mechanism for this type of memory. We therefore studied the induction of synaptic plasticity in rat PFC neurons, maintained in vitro, with special emphasis on the functionally important neuromodulator dopamine. First, the induction of long-term potentiation (LTP) was facilitated in the presence of tonic/background dopamine in the bath, and the dose-dependency of this background dopamine followed an “inverted-U” function, where too high or too low dopamine levels could not facilitate LTP. Second, the induction of long-term depression (LTD) by low-frequency stimuli appeared to be independent of background dopamine, but required endogenous, phasically-released dopamine during the stimuli. Blockade of dopamine receptors during the stimuli and exaggeration of the effect of this endogenously-released dopamine by inhibition of dopamine transporter activity both blocked LTD. Thus, LTD induction also followed an inverted-U function in its dopamine-dependency. We conclude that PFC synaptic plasticity is powerfully modulated by dopamine through inverted-U-shaped dose-dependency. © 2015, Shanghai Institutes for Biological Sciences, CAS and Springer-Verlag Berlin Heidelberg.
Kawasaki T.,Ryotokuji University |
Kawasaki T.,Tokyo Metroplitan University |
Higuchi T.,Tokyo Metroplitan University
Journal of Motor Behavior | Year: 2016
In a study on postural stability, the authors examined whether the effects of mental rotation (MR) intervention using a foot stimulus would last for a relatively long time (up to 60 min). The participants performed a randomly assigned MR task (using foot stimuli, hand stimuli, or non–body-related stimuli [car]) for 10 min. The amount of body sway during unipedal standing was measured immediately after the intervention and 10, 30, and 60 min after the intervention. Results showed that MR intervention using foot stimuli was more effective than that using hand or car stimuli. This suggests that foot stimuli, rather than body-related stimuli, would be advantageous for the intervention. The results show that beneficial effects were observed 60 min after the intervention; this indicates that the effects of the foot MR were unlikely to be explained on the basis of enhanced corticospinal excitability involving motor execution. The authors discuss a potential explanation for the effects and application of the MR task in a clinical setting. Copyright © 2016 Taylor & Francis Group, LLC
Blot K.,University Pierre and Marie Curie |
Bai J.,University Pierre and Marie Curie |
Otani S.,University Pierre and Marie Curie |
Otani S.,Ryotokuji University
Journal of Physiology Paris | Year: 2013
Schizophrenia affects about 1% of the world population and is a major socio-economical problem in ours societies. Cognitive symptoms are particularly resistant to current treatments and are believed to be closely related to an altered function of prefrontal cortex (PFC). Particularly, abnormalities in the plasticity processes in the PFC are a candidate mechanism underlying cognitive symptoms, and the recent evidences in patients are in line with this hypothesis. Animal pharmacological models of cognitive symptoms, notably with non-competitive NMDA receptor antagonists such as MK-801, are commonly used to investigate the underlying cellular and molecular mechanisms of schizophrenia. However, it is still unknown whether in these animal models, impairments in plasticity of PFC neurons are present. In this article, we briefly summarize the current knowledge on the effect of non-competitive NMDA receptor antagonist MK-801 on medial PFC (mPFC) neuronal activity and then introduce a form of plasticity found after acute exposure to MK-801, which was accompanied by cognitive deficits. These observations suggest a potential correlation between cognitive deficits and the aberrant plasticity in the mPFC in the animal model of schizophrenia. © 2013 Elsevier Ltd.
Miyashita K.,Chubu University |
Kobayashi H.,Nihon Fukushi University |
Koshida S.,Ryotokuji University |
Urabe Y.,Hiroshima University
American Journal of Sports Medicine | Year: 2010
Background: Because a majority of throwing injuries occur near the maximum external rotation (MER) of the throwing shoulder, sports medicine practitioners and researchers have paid special attention to the shoulder kinematics at the MER in throwing. However, little is known about the individual kinematics of the glenohumeral, scapulothoracic, and thoracic joints at the MER. Purpose: To demonstrate the glenohumeral, scapulothoracic, and thoracic joint movements and their contribution to the MER in throwing for baseball players. Study Design: Descriptive laboratory study. Methods: We collected throwing motion data for 20 collegiate baseball players by using 3 high-speed cameras and established 3-dimensional coordinates of each landmark with a direct linear translation method. We then obtained the MER of the shoulder complex, the external rotation angle of the glenohumeral joint, the posterior tipping angle of the scapula, and the thoracic extension angles at the MER in throwing. Results: The mean (± standard deviation) value of the MER was 144.2° ± 11.0°. The mean (± standard deviation) values of the glenohumeral external rotation, the scapular posterior tipping, and the thoracic extension angles at the MER were 105.7° ± 15.5°, 23.5° ± 13.9°, and 8.9° ± 7.3°, respectively. Conclusion: Our results indicate that not only the glenohumeral joint movement but also the scapular and thoracic movements make major contributions to the MER angle. Clinical Relevance: To better understand the pathomechanics of the shoulder complex in throwing, we need to take into account the individual contributions of the glenohumeral, scapulothoracic, and thoracic extension movements to the MER.