Nishimura H.,University of Tennessee Health Science Center |
Nishimura H.,Niigata University of Health and Welfare |
Yang Y.,University of Tennessee Health Science Center |
Yang Y.,University of Colorado at Denver
American Journal of Physiology - Regulatory Integrative and Comparative Physiology | Year: 2013
For terrestrial vertebrates, water economy is a prerequisite for survival, and the kidney is their major osmoregulatory organ. Birds are the only vertebrates other than mammals that can concentrate urine in adaptation to terrestrial environments. Aquaporin (AQP) and glyceroporin (GLP) are phylogenetically old molecules and have been found in plants, microbial organisms, invertebrates, and vertebrates. Currently, 13 AQPs/ aquaGLPs and isoforms are known to be present in mammals. AQPs 1, 2, 3, 4, 6, 7, 8, and 11 are expressed in the kidney; of these, AQPs 1, 2, 3, 4, and 7 are shown to be involved in fluid homeostasis. In avian kidneys, AQPs 1, 2, 3, and 4 have been identified and characterized. Also, gene and/or amino acid sequences of AQP5, AQP7, AQP8, AQP9, AQP11, and AQP12 have been reported in birds. AQPs 2 and 3 are expressed along cortical and medullary collecting ducts (CDs) and are responsible, respectively, for the water inflow and outflow of CD epithelial cells. While AQP4 plays an important role in water exit in the CD of mammalian kidneys, it is unlikely to participate in water outflow in avian CDs. This review summarizes current knowledge on structure and function of avian AQPs and compares them to those in mammalian and nonmammalian vertebrates. Also, we aim to provide input into, and perspectives on, the role of renal AQPs in body water homeostasis during ontogenic and phylogenetic advancement. © 2013 the American Physiological Society.
Tanaka Y.,Niigata University of Health and Welfare |
Nishio M.,Niigata University of Health and Welfare |
Niimi S.,International University of Health and Welfare
Folia Phoniatrica et Logopaedica | Year: 2011
Speech samples obtained from 39 idiopathic Parkinson's disease (PD) patients with vocal pathologies were compared with those from 62 age-matched vocally normal non-PD controls. Voice samples collected from sustained vowel phonation and passage reading were acoustically analyzed using Computer Speech Lab and Multi-Dimensional Voice Program software. Noise-to-harmonic ratio, voice turbulence index (VTI) and soft phonation index (SPI) were incorporated as noise-related measurements, fundamental frequency-tremor intensity index (FTRI), amplitude tremor intensity, fundamental frequency-tremor frequency (Fftr), and amplitude-tremor frequency as tremor-related measurements. Compared with controls, the following results were noted: (1) male and female PD patients exhibited significant differences in acoustic parameters of all frequency and amplitude perturbation measurements and noise-related measurements (except VTI in males); (2) speaking fundamental frequency was significantly higher only in male PD patients; (3) FTRI and Fftr in male (only FTRI in female) PD patients were significantly higher, and (4) disease severity and MDVP analysis showed significant correlations between SPI and the Unified Parkinson's Disease Rating Scale Part I (mentation, behavior, mood) and Part II (activities of daily living) in male PD patients; however, this was not the case in female PD patients. © 2011 S. Karger AG, Basel.
Sahu A.,University of Pittsburgh |
Koshinaka K.,University of Pittsburgh |
Koshinaka K.,Niigata University of Health and Welfare |
Sahu M.,University of Pittsburgh
Journal of Neuroendocrinology | Year: 2013
Leptin, the product of the obese gene, regulates energy homeostasis by acting primarily at the level of the hypothalamus. Leptin action through its receptor involves various pathways, including the signal transducer and activator of transcription (STAT)3, phosphatidylinositol 3-kinase (PI3K), and phosphodiesterase 3B (PDE3B)-cAMP signalling in the central nervous system and peripheral tissues. In the hypothalamus, leptin stimulates STAT3 activation, and induces PI3K and PDE3B activities, among others. We have previously demonstrated that PDE3B activation in the hypothalamus is critical for transducing the anorectic and body weight reducing effects of leptin. Similarly, PI3K has been implicated to play a critical role in leptin signalling in the hypothalamus. Although, in the insulin signalling pathway, PI3K is known to be an upstream regulator of PDE3B in non-neuronal tissues, it is still unknown whether this is also the case for leptin signalling in the hypothalamus. To address this possibility, the effect of wortmannin, a specific PI3K inhibitor, was examined on leptin-induced PDE3B activity in the hypothalamus of male rats. Intracerebroventricular injection of leptin (4 μg) significantly increased PDE3B activity by two-fold in the hypothalamus as expected. However, previous administration of wortmannin completely reversed the stimulatory effect of leptin on PDE3B activity in the hypothalamus. To investigate whether leptin stimulates phospho (p)-Akt levels and that there might be a possible upstream regulator of PDE3B, we examined the effects of i.c.v. leptin on p-Akt levels in the hypothalamus and compared them with the known stimulatory effect of insulin on p-Akt. We observed that insulin increased p-Akt levels but leptin failed to do so, although it increased p-STAT3 levels, in the rat hypothalamus. Immunocytochemistry confirmed the biochemical findings in that leptin failed but insulin increased the number of p-Akt positive cells in various hypothalamic nuclei. Taken together, these results implicate PI3K but not Akt as an upstream regulator of the PDE3B pathway of leptin signalling in the rat hypothalamus. © 2012 British Society for Neuroendocrinology.
Tamaki H.,Niigata University of Health and Welfare
Journal of musculoskeletal & neuronal interactions | Year: 2013
The present study aimed to clarify the structural recovery, and to compare the time course of morphological changes in trabeculae and the process of bone mass change in rat tibiae following temporary immobilization of hind limb by sciatic neurectomy or nerve freezing. In 11-week-old male Fischer 344 rats, 4-5 mm of the sciatic nerve was removed (neurectomy group) or frozen by 5-second application of a stainless steel rod immersed in liquid nitrogen (nerve-freezing group). Quantitative changes in cancellous bone were assessed by histomorphometry. The results clarified that: trabecular bone volume (BV/TV) decreases until 3 weeks after denervation, and in the nerve-freezing group, it then increases from week 4, recovering to pre-surgery levels by week 10 (no recovery was seen in the neurectomy group); in the initial phase of bone atrophy, the decrease in BV/TV is more gradual in the nerve-freezing group than in the neurectomy group; and changes in trabecular architecture in the bone atrophy-recovery process are strongly associated with changes in trabecular thickness. The findings suggested that after transient injury by nerve freezing and subsequent recovery of neuromuscular function, bone tissue undergoes recovery from bone loss, but that trabeculae may not show complete structural recovery.
Sakuma M.,Niigata University of Health and Welfare
Clinical calcium | Year: 2012
Osteoporosis is one of the main diseases of the locomotive syndrome. Exercise therapy is a basic approach for prevention and treatment of osteoporosis, and is effective for increasing bone mineral density and preventing fall. Single foothold standing with the eyes open for one minute and squatting by "rokotore" are recommended as exercises that are easy for elderly people. Strengthening of back muscles is also useful for prevention of round back due to osteoporosis. We suggest that improved outcomes may be achieved by combining some of these exercises.
Kushida O.,Niigata University of Health and Welfare
[Nihon kōshū eisei zasshi] Japanese journal of public health | Year: 2012
A core construct of the Transtheoretical model is that the processes and stages of change are strongly related to observable behavioral changes. We created the Processes of Change Scale of vegetable consumption behavior and examined the validity and reliability of this scale. In September 2009, a self-administered questionnaire was administered to male Japanese employees, aged 20-59 years, working at 20 worksites in Niigata City in Japan. The stages of change (precontempration, contemplation, preparation, action, and maintenance stage) were measured using 2 items that assessed participants' current implementation of the target behavior (eating 5 or more servings of vegetables per day) and their readiness to change their habits. The Processes of Change Scale of vegetable consumption behavior comprised 10 items assessing 5 cognitive processes (consciousness raising, emotional arousal, environmental reevaluation, self-reevaluation, and social liberation) and 5 behavioral processes (commitment, rewards, helping relationships, countering, and environment control). Each item was selected from an existing scale. Decisional balance (pros [2 items] and cons [2 items]), and self-efficacy (3 items) were also assessed, because these constructs were considered to be relevant to the processes of change. The internal consistency reliability of the scale was examined using Cronbach's alpha. Its construct validity was examined using a factor analysis of the processes of change, decisional balance, and self-efficacy variables, while its criterion-related validity was determined by assessing the association between the scale scores and the stages of change. The data of 527 (out of 600) participants (mean age, 41.1 years) were analyzed. Results indicated that the Processes of Change Scale had sufficient internal consistency reliability (Cronbach's alpha: cognitive processes=0.722, behavioral processes=0.803). The processes of change were divided into 2 factors: "consciousness raising, emotional arousal, environmental reevaluation, self-reevaluation, commitment, rewards, helping relationships, and social liberation" and "countering and environment control" in the factor analysis. Moreover, each construct--the processes of change, decisional balance, and self-efficacy--could be classified into different factors. The scores for cognitive processes were higher in the contemplation and preparation stages than in the precontemplation stage (P<0.05). Scores for behavioral processes increased from the precontemplation stage to the preparation stages (P<0.05), and were higher in the action + maintenance stage than in the precontemplation stage (P< 0.05). For male workers, the Processes of Change Scale has sufficient validity and reliability, as demonstrated by the internal fitness and the construct and criterion-related validity of the scale found in this study.
Sargent B.,University of Southern California |
Schweighofer N.,University of Southern California |
Kubo M.,Niigata University of Health and Welfare |
Fetters L.,University of Southern California
PLoS ONE | Year: 2014
A critical issue in the study of infant development is to identify the processes by which task-specific action emerges from spontaneous movement. Emergent leg action has been studied by providing contingent reinforcement to specific leg movements using an overhead infant-activated mobile, however, there is limited information on the strategies used by infants to support the emergence of task-specific leg action from spontaneous movement. The purpose of this study is to (1) determine the ability of 3 month old infants to learn, through discovery, the contingency between leg action and mobile activation using a virtual threshold, and (2) identify strategies, defined by variance of the end-effectors (feet) and hip-knee joint coordination, used by infants that learned the contingency. Fourteen 3 month old infants participated in 2 sessions of mobile reinforcement on consecutive days. As a group, infants increased the percentage of mobile activation to meet performance criteria on Day 2, but did not meet memory or learning criteria across days. However, five infants learned the contingency based on individual learning criteria. When interacting with the mobile on Day 2 as compared to spontaneous kicking on Day 1, infants who learned the contingency, but not infants who did not learn the contingency, increased variance of the end-effectors (feet) in the vertical, task-specific direction and demonstrated less in-phase hip-knee joint coordination. An important discovery is that infants can discover this very specific contingency, suggesting that this movement behavior (action) can be shaped in future work. This may have implications for the rehabilitation of infants with atypical leg action. © 2014 Sargent et al.
Matsui T.,University of Tsukuba |
Soya S.,University of Tsukuba |
Okamoto M.,University of Tsukuba |
Ichitani Y.,University of Tsukuba |
And 2 more authors.
Journal of Physiology | Year: 2011
Brain glycogen could be a critical energy source for brain activity when the glucose supply from the blood is inadequate (hypoglycaemia). Although untested, it is hypothesized that during prolonged exhaustive exercise that induces hypoglycaemia and muscular glycogen depletion, the resultant hypoglycaemia may cause a decrease in brain glycogen. Here, we tested this hypothesis and also investigated the possible involvement of brain monoamines with the reduced levels of brain glycogen. For this purpose, we exercised male Wistar rats on a treadmill for different durations (30-120 min) at moderate intensity (20 m min -1) and measured their brain glycogen levels using high-power microwave irradiation (10 kW). At the end of 30 and 60 min of running, the brain glycogen levels remained unchanged from resting levels, but liver and muscle glycogen decreased. After 120 min of running, the glycogen levels decreased significantly by ∼37-60% in five discrete brain loci (the cerebellum 60%, cortex 48%, hippocampus 43%, brainstem 37% and hypothalamus 34%) compared to those of the sedentary control. The brain glycogen levels in all five regions after running were positively correlated with the respective blood and brain glucose levels. Further, in the cortex, the levels of methoxyhydroxyphenylglycol (MHPG) and 5-hydroxyindoleacetic acid (5-HIAA), potential involved in degradation of the brain glycogen, increased during prolonged exercise and negatively correlated with the glycogen levels. These results support the hypothesis that brain glycogen could decrease with prolonged exhaustive exercise. Increased monoamines together with hypoglycaemia should be associated with the development of decreased brain glycogen, suggesting a new clue towards the understanding of central fatigue during prolonged exercise. ©2011 The Authors. Journal compilation © 2011 The Physiological Society.
Hagihara Y.,Niigata University of Health and Welfare |
Nara T.,Niigata University of Health and Welfare
American Journal of Physical Anthropology | Year: 2016
Objective: The Jomon, one of the ancestral populations of modern Japanese, were hunter-gatherers inhabiting the Japanese archipelago from 11,000 to 300 BC. We evaluated changes in the diaphyseal morphology of the fibula from the middle to the final phase of the Jomon period, compared to the morphology of other historical and modern populations from the Japanese archipelago, to elucidate temporal changes in habitual activities and possible division of labor among males and females. Material and Method: Jomon specimens of 107 males and 97 females were obtained from the shell mounds of the Pacific coastal area of East Japan, distinguishing between middle (3,000–2,000 BC) and late-final (2,000–300 BC) phases of the Jomon period. Mid-shaft morphology of the fibula and tibia were compared to morphological measurements of specimens from Yayoi (37 males, 28 females), medieval (56 males, 56 females), early modern (51 males, 50 females), and modern (125 males, 68 females) periods. Result: Largest values of fibular areas and relative fibular-to-tibial areas were identified in males from the late-final Jomon phase, compared to the middle Jomon phase and after the Yayoi period. These period-specific differences in fibular area were smaller in females, with the largest between-sex difference identified in the late-final Jomon phase. Discussion: Results confirm a change in the habitual activity pattern of males in the late-final phase. Males of the late-final Jomon phase likely did more long-distance traveling to the inland/mountainous region, as part of an ecological change that occurred during the middle to the late-final Jomon phase. Am J Phys Anthropol 160:708–718, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.
Yamada S.,Nagoya University |
Shimizu Y.,Nagoya University |
Suzuki M.,Niigata University of Health and Welfare |
Izumi T.,Kitasato University
Circulation Journal | Year: 2012
Background: Although functional limitations (FLs) can predict clinical deterioration in chronic heart failure (CHF), few studies have focused on the associated clinical significance. The aim of the present study was to examine the association between FL and changes in the related time course with subsequent hospital readmission in CHF patients. Methods and Results: FLs were analyzed using the Performance Measure for Activities of Daily Living-8 (PMADL- 8; higher scores indicate worse FLs) for 215 CHF patients at 1 and 3 months after discharge in a multicenter cohort study. The mean follow-up was 20 months. In a multivariate Cox regression analysis including covariates, only the PMADL-8 score remained significantly related to rehospitalization of CHF (hazard ratio, 2.49; 95% confidence interval: 1.27-4.90; P<0.01). Event-free survival differed significantly among the 4 PMADL-8 time-course groups (P<0.01). The persistent low-FL group had lower event rates than the other 3 time-course groups (P<0.01). Conclusions: FLs as measured by the PMADL-8 and the time course of the PMADL-8 score predict readmission in CHF patients after discharge. Accordingly, FL assessment is recommended as part of the clinical management because it not only identifies decline in physical function but also guides prognosis in CHF patients.