Evaluation of postural control in quiet standing using center of mass acceleration: comparison among the young, the elderly, and people with stroke.

OBJECTIVE: To determine center of mass (COM) acceleration usefulness in the evaluation of postural control during quiet standing. DESIGN: Three-group comparison design. SETTING: A research laboratory. PARTICIPANTS: Poststroke subjects (n=12), healthy elderly subjects (n=22), and healthy young subjects (n=25). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: With a force platform, postural sway was evaluated by using the standard deviations of COM acceleration and center of pressure (COP) and COM (COP-COM) in which COP-COM represents the distance between the COP and the COM. RESULTS: COM acceleration and COP-COM variables were greater in the poststroke group than in the healthy groups (elderly and young) in the mediolateral (ML) direction. Both variables in the anteroposterior (AP) direction were greater in the poststroke group and the elderly group than in the young group. Furthermore, the correlations between COM acceleration and COP-COM in each group in each direction were shown to be significantly high (r range, .906-.979; P<.001). CONCLUSIONS: COM acceleration was useful in the evaluation of postural control during quiet standing when comparing the young, the elderly, and poststroke patients. Additionally, COM acceleration and COP-COM in both the AP and ML directions during quiet standing were significantly and highly correlated. Thus, we proposed that COM acceleration can be an alternative and convenient measure instead of COP-COM in the evaluation of postural control.

Role of mouse organic anion transporter 3 (mOat3) as a basolateral prostaglandin E2 transport pathway.

Renal organic anion transporters play an important role in the handling of a number of endogenous and exogenous anionic substances in the kidney. In this study, we investigated prostaglandin E(2) (PGE(2)) transport properties and intrarenal localization of mouse organic anion transporter 3 (mOat3). When expressed in Xenopus oocytes, mOat3 mediated the time- and concentration-dependent transport of PGE(2) (K(m): 1.48 microM). PGE(2) transport mediated by mOat3 was trans-stimulated by intracellular glutarate injected into the oocytes. PGE(2) efflux via mOat3 was also trans-stimulated by extracellular glutarate. Thus, mOat3 was shown to mediate the bidirectional transport of PGE(2), partly coupled to the dicarboxylate exchange mechanism. Immunohistochemical study revealed that mOat3 protein was localized at the basolateral membrane of renal proximal and distal tubules. Furthermore, diffuse expression of mOat3, including expression in the basolateral membrane in macula densa (MD) cells, was observed. These results indicate that mOat3 plays an important role as a basolateral transport pathway of PGE(2) in the distal nephron including MD cells that may constitute one of the indispensable steps for renin release and regulation of the tubuloglomerular feedback mechanism.

[Health-related quality of life factor in chronic hemodialysis patients].

AIM: The purpose of this study was to investigate the related factors of the health-related quality of life (HRQOL) measured by KDQOL-SF version 1.3 Japanese version) in chronic hemodialysis patients. METHODS: Using a cross-sectional survey design, we hand-delivered a self-administered questionnaire to the chronic hemodialysis patients and finally obtained 67 subjects' data to analyze. The response rate was 65.7%. Among the related factors, disease/dialysis-related factors and rehabilitation-related factors in addition to demographic factors were examined. The HRQOL was divided into a physical component summary (PCS) and a mental component summary (MCS). RESULTS: Multiple linear regression analysis revealed that the independent factors related to PCS were symptom score, serum albumin level, patients' satisfaction with dialysis care, and the work status. These four factors could explain 60% of PCS variance (adjusted R2 = 0.601). The independent factors related to MCS were revealed to be quality of social interaction and understanding of effectiveness of self-exercise. These two factors could explain only a quarter of MCS variance (adjusted R 2 = 0.223). CONCLUSION: These results suggest that highly satisfactory care of dialysis, improvement of dialysis-related symptoms, and good nutritional management are important for improving HRQOL in chronic hemodialysis patients, and that the promotion of social participation and interpersonal relationships as well as a positive attitude to self-exercise may lead to a beneficial outcome of rehabilitation for chronic hemodialysis patients.