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Hiroyuki Furuya

Publications and source records attributed to Hiroyuki Furuya.

3 recordsLinked to original sources

Spatial reference and standing posture during high-speed Coriolis stimulation.

BACKGROUND: In a previous study, we found that sensation, gaze, and posture during Coriolis stimulation differ considerably between vision and nonvision conditions during rotations at 60 degrees x s(-1). To determine the validity of these findings at higher velocities, we compared standing postures during Coriolis stimulation up to 150 degrees x s(-1) between vision and nonvision conditions. METHODS: The 19 subjects underwent 5-min rotation tests at 50 to 150 degrees x s(-1). While standing on a force platform attached to a rotating device, each subject tilted his or her head and then returned it to upright, first with the eyes covered, then with eyes open. Six subjects were re-examined 5 d later after 4 consecutive days of 20-min rotations with their eyes open. We assessed success and failure to stand and recorded the center of pressure during rotation. RESULTS: Although success rates (number of successes/19) differed between vision and nonvision conditions at 50 degrees x s(-1) (94.7% vs. 57.9%), they steeply decreased as rotation velocity increased and showed no difference at 70 degrees x s(-1) and faster velocities. After the 4-d exposure, however, subjects could stand at higher velocities particularly under the vision condition. A patient with bilateral labyrinthine loss, being examined for reference, could stand at 110 degrees x s(-1) even with the eyes covered. CONCLUSIONS: Untrained subjects frequently fell during high-speed Coriolis stimulation, apparently because vision was insufficient to provide a spatial reference frame from the stationary surroundings. Following rotation training with their eyes open, subjects appeared more able to use the visual reference frame and falls were reduced.

Adult↗

[Associations between glycated hemoglobin levels and atherosclerotic risk factors in urban communities].

PURPOSE: To prevent coronary heart disease and type 2 diabetes mellitus, we need to focus on "the deadly quartet" (coexistence of upper-body obesity, glucose intolerance, hypertriglyceridemia, and hypertension), and the multiple risk factor syndrome related to insulin resistance. As few urban community-based population studies have evaluated the correlation between glycated hemoglobin A1c (HbA1c) levels and risks of life-style related disease, we investigated this parameter and its correlation with atherosclerotic risk factors in participants of health check ups in two communities in Kanagawa prefecture. We also examined whether these correlations were affected by difference between the two groups. METHODS: The study populations comprised male and female residents aged 40-79 in two communities (A and B cities) in 1998. Age, body mass index (BMI), systolic blood pressure (SBP), diastolic blood pressure (DBP), total cholesterol (TC), HDL-cholesterol (HDL-C), triglycerides (TG), GOT, GPT, Uric acid (UA), and gamma GTP were considered as atherosclerotic risk factors. Firstly we calculated correlation coefficients with HbA1c level. Secondly, logistic regression analyses were performed with HbA1c as the dependent variable, and risk factors correlated with HbA1c significantly and variable for each community as independent variables. To assess whether community differences affect associations between HbA1c levels and risk factors, we added interaction terms as independent variables in the logistic regression analysis. RESULTS: 1. There were no significant interaction terms while significant positive associations were observed between HbA1c and age, BMI, and levels of TC and gamma GTP for men in both communities. A significant negative association was observed between HbA1c and UA.. 2. Age, BMI, and the levels of SBP, TG, GPT, and gamma GTP were positively associated, and GOT was negatively associated with the HbA1c levels in women in both communities. Each community had its own association between TC and HbA1c. CONCLUSIONS: The findings that TC is associated with HbA1c in men, and that BMI and the level of TC are linked with HbA1c in women are consistent with previous results for Japanese. The association between HbA1c and TG in women was newly observed for Japanese. Furthermore, the levels of gamma GTP in both sexes and also GPT in women are associated with HbA1c. From these results, investigating linkage between HbA1c level and atherosclerotic risk factors was thought to be appropriate for estimating accumulation of multiple risk factors in the community.

Adult↗

Effect of ethanol and docosahexaenoic acid on nerve growth factor-induced neurite formation and neuron specific growth-associated protein gene expression in PC12 cells.

It is known that prenatal and postnatal exposure to ethanol can result in hyperactive behavior and learning disturbance in offspring. We have previously shown that docosahexaenoic acid (DHA) ameliorated hyperactivity induced by in utero ethanol exposure in rat pups. The present study is designed to clarify the effects of DHA on neurite outgrowth and gene expression of GAP-43 and SCG10, neuron specific growth-associated proteins (GAPs) in PC12 cells treated with ethanol. Ethanol seemed to enhance the neurite outgrowth induced by nerve growth factor (NGF). DHA administration further increased neurite outgrowth in both NGF alone and the combination of NGF and ethanol treated PC12 cells. DHA treatment increased the levels of both GAP-43 and SCG10 mRNAs, and simultaneous administration of ethanol suppressed the elevation of GAP-43 and SCG10 mRNA enhanced by DHA. The present study has demonstrated, for the first time, the effect of ethanol and DHA on GAPs' gene expression. Interaction of ethanol and docosahexaenoic acid in NGF-induced neurite formation, as well as the mechanisms by which DHA ameliorate the hyperactivity induced by in utero ethanol exposure, are to be elucidated.

Animals↗