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Purpose . The aim of the study was to examine the effects of Tai Chi (TC) training on postural control when upright standing was perturbed by upper limb movement. Methods . Three groups, TC, Brisk walk (BW), and sedentary (SE), of thirty-six participants aged from 65 to 75 years were recruited from local community centers. Participants performed static balance task (quiet standing for 30 s with eyes open and closed) and fitting task (two different reaching distances X three different opening sizes to fit objects through). During tasks, the COP data was recorded while standing on the force plate. Criteria measures calculated from COP data were the maximum displacement in anterior-posterior (AP) and medial-lateral (ML) directions, the 95% confidence ellipse area (95% area), and the mean velocity. Results . No significant effect was observed in the static balance task. For fitting tasks, the group effect was observed in all directions on COP 95% area ( p < 0.05) and the TC group showed reduced area. The tests of subject contrasts showed significant trends for reaching different distances and fitting different openings conditions in all directions, the 95% area, and the mean velocity ( p < 0.05). Conclusion . Compared to the other two groups, long-term TC exercise helps in reducing the effects of upper body perturbation as measured by posture sway., Competing Interests: The authors declare that there is no conflict of interests regarding the publication of this paper.

Introduction: People with Peripheral Neuropathy (PN), especially those with impaired sensory inputs through the small-afferent fiber (type II afferent fibers) reflex loop (SAF), might depend more on the large-afferent fiber (type I afferent fibers) reflex loop (LAF) for postural control., Purpose: To examine whether the function of the LAF reflex loop, reflected by the H-reflex and ankle joint proprioception, influences postural control when the SAF reflex loop is impaired, as indicated by reduced foot sole cutaneous sensation., Methods: Thirteen participants (8 women, 5 men) diagnosed with PN and 12 age-matched controls (7 women, 5 men) completed the testing protocol. Measures of interest included the H-index, active (AAP) and passive (PAP) ankle proprioception, plantar pressure sensitivity (PPS), average sway velocity (VAVG) and area (A95) during 30 seconds eyes-closed standing, 6-minute walk distance (6MWD) and timed up-and-go duration (TUG)., Results: Statistically significant group-dependent regression was observed between VAVG and H-index. Compared to the control group, the PN group demonstrated reduced PPS (2.0 ± 1.9 vs. 4.2 ± 1.2, P < .05) and H-index (63.6 ± 10.9 vs. 76.4 ± 16.0, P < .05), greater VAVG (3.5 ± 2.1 vs. 1.6 ± 0.6 cm/s, P < .05) and A95 (10.0 ± 10.1 vs. 2.5 ± 1.5 cm2, P < .05), shorter 6MWD (442.2 ± 93.0 vs. 525.3 ± 68.2 m, P < .05), and longer TUG (9.4 ± 1.6 vs. 6.5 ± 1.3 s, P < .05). Within the PN group, but not the control group, the H-index was correlated with VAVG (r = -.56, P < .05). Moreover, within the PN group only, PAP scores were correlated with 6MWD (r = -.68, P < .05) and TUG (r = -.59, P < .05) performance. No other statistically significant group difference, correlation or group-dependent regression was observed., Conclusion: VAVG, 6MWD, and TUG correlated with LAF reflex loop function observed among those with impaired functioning of the SAF reflex loop. This observation suggests that the LAF reflex loop may be critical to the control of balance in those individuals suffering from small-fiber PN.

Examining degenerative sensory and reflexive activity among people with peripheral neuropathy (PN) is important for clinical examinations and understanding relevant neural impairments. However, other than the test of presynaptic inhibition, the reliability of other related tests is largely unknown. The purpose of this project was to examine the test-retest reliability of lower extremity sensory and reflexive measures in people with PN. Twelve participants (8 women, 4 men, age = 72.5 ± 9.2 years) diagnosed with PN were assessed on two occasions at least 7 d apart. Plantar sensitivity, H-reflex and active and passive ankle proprioception (AAP and PAP) were tested. Paired student's t-test and Intraclass correlation coefficients (ICC) were used for statistical analysis. Significant difference was observed in AAP at 0º position (p = 0.04). No other significant differences were observed. Moderate to high reliability was observed at measures of Plantar sensitivity (0.92), peak to peak H (0.71) and M (0.84) waves, latency between H and M (0.78), H-Index (0.85), AAP (0.62) and PAP index (0.60). Low reliability was observed of other parameters. The measures of Hmax, Mmax, latency, H-Index, plantar sensitivity and AAP & PAP indices of proprioception tests can be measured reliably for further study in this population.

Objectives: To identify randomized controlled trials comparing the use of hydrophilic and nonhydrophilic catheters for intermittent catheterization (IC) in patients with spinal cord injury (SCI), and to perform a meta-analysis evaluating the occurrence of hematuria and urinary tract infection (UTI)., Data Sources: We searched the following electronic databases to identify studies: EMBASE (1991 to August 2011), PubMed (1991 to August 2011), Cochrane Library (no date restriction), China National Knowledge Infrastructure (no date restriction), and the Chinese Biomedical Literature Database (no date restriction)., Study Selection: Randomized controlled trials, parallel-control, crossover-control, and prospective cohort studies that assessed morbidity associated with the use of hydrophilic catheters and nonhydrophilic catheters in patients after SCI were included., Data Extraction: Data extraction was performed using standardized forms of the Cochrane Collaboration. Methodologic quality was independently assessed by 2 reviewers using the Downs and Black instrument. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated for dichotomous data., Data Synthesis: Five studies involving 508 subjects; 462 subjects completed the study and were included in this meta-analysis. There was a significantly lower incidence (OR=.36; 95% CI, 24%-54%; P<.0001) of reported UTIs in the hydrophilic-treated group compared with the nonhydrophilic-treated group. Hematuria was also reported significantly less in the hydrophilic catheter group than in the nonhydrophilic catheter group (OR=.57; 95% CI, 35%-92%; P=.001)., Conclusions: This meta-analysis found UTIs and hematuria less frequently associated with the use of hydrophilic-coated catheters for IC in patients with SCI. These findings support the use of hydrophilic catheters in this patient population., (Copyright © 2013 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.)

Unlabelled: Foot sole tactile sensation provides valuable feedback to the central nervous system. Acutely reduced foot sensation changes plantar pressure distribution in standing and gait; however, the effect of chronic foot sole sensory impairment on plantar pressure distribution is unclear., Purpose: This study aims to examine the effects of peripheral neuropathy (PN) induced chronic sensory loss on plantar pressure distribution in walking and standing., Methods: Foot sole sensitivity was tested at the five sites: big toe (BT), 1st metatarsal (M1), 5th metatarsal (M5), mid-foot (MF) and heel (HL). Relative peak pressures (RPP) of the five sites were collected during a 20-s walking on a treadmill at .45 m/s and a 30-s quiet standing with eyes open. Five-way MANOVA was used to examine the influence of sensitivity of each site on overall plantar pressure distribution for standing and walking separately. Tukey's test was used to examine the significant associations., Results: In standing, the sensitivity of BT affected average RPP at BT significantly (P<.05), where RPP associated with insensitive BT (8.1±5.7%) was greater than with sensitive BT (4.5±4.9%). Furthermore, the RPP at HL was greater for insensitive MF (36.1±17.9%) compared with sensitive MF (23.6±7.4%) (P<.05). No pressure distribution changes were observed in walking., Conclusions: Feedback from foot sole tactile sensation in gait is not as significant as in standing, showing standing balance control relies more on feedback control mechanism while gait control relies more on feed forward control mechanism., (Published by Elsevier B.V.)

Background and Objectives: Involuntary autobiographical memories that spring unbidden into conscious awareness form part of everyday experience. In psychopathology, involuntary memories can be associated with significant distress. However, the cognitive mechanisms associated with the development of involuntary memories require further investigation and understanding. Since involuntary autobiographical memories are image-based, we tested predictions that visuospatial (but not other) established cognitive tasks could disrupt their consolidation when completed post-encoding., Methods: In Experiment 1, participants watched a stressful film then immediately completed a visuospatial task (complex pattern tapping), a control-task (verbal task) or no-task. Involuntary memories of the film were recorded for 1-week. In Experiment 2, the cognitive tasks were administered 30-min post-film., Results: Compared to both control and no-task conditions, completing a visuospatial task post-film reduced the frequency of later involuntary memories (Expts 1 and 2) but did not affect voluntary memory performance on a recognition task (Expt 2)., Limitations: Voluntary memory was assessed using a verbal recognition task and a broader range of memory tasks could be used. The relative difficulty of the cognitive tasks used was not directly established., Conclusions: An established visuospatial task after encoding of a stressful experience selectively interferes with sensory-perceptual information processing and may therefore prevent the development of involuntary autobiographical memories., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Amyloids are insoluble, fibrous proteins formed through the aggregation of misfolded proteins. They accumulate in the tissue of individuals with degenerative diseases, such as Parkinson's and Alzheimer's. The purpose of this study was to determine whether fibril growth from an initial model fibril seed is unidirectional or bidirectional. The prevailing theory on amyloid formation is that a symmetric fibril elongates equally from both ends. This study provides evidence to the contrary; the process occurs predominately unidirectionally, demonstrating that amyloid fibrils may be asymmetric and propagate mostly in one direction. Alexa Fluor 568 labeled insulin fibrils were seeded into a native insulin solution and allowed to elongate at 65°C while the kinetics of fibril growth was monitored. The resulting elongated fibrils were labeled with thioflavin-T, and the fluorescent images of the fibrils show that a majority of the elongated fibrils propagated along only one end of the seed, with the remaining labeled fibrils having bidirectional elongation or no elongation. Using a crystallographic model, we offer a structural explanation for asymmetric growth of the insulin fibrils. Thus, instead of the current view that fibrils grow symmetrically from both ends of the fibril, this is the first evidence that insulin amyloid fibrils formed in solution are asymmetric and appear to grow from only one end., (Copyright © 2010 Wiley-Liss, Inc.)

Background: In animal models, circulating endothelial progenitor cells (EPC) have been shown to participate in repair of damaged or degenerating vascular surfaces. In humans, reduced EPC counts correlate with cardiovascular risk and disease outcome; yet it has been difficult to establish that EPC are in fact mobilized in response to vascular injury as a physiologic response. We therefore studied early (<12h) mobilization of EPCs into the peripheral circulation after a defined vascular manipulation, percutaneous coronary intervention (PCI) in acute coronary syndrome (ACS) and non-ACS patients., Methods and Results: CD34/CD31 positive EPC colony forming units (EPC-CFU) were quantified by a blinded observer in peripheral blood samples from eight control patients with angiographically normal coronary arteries, and in 30 patients with coronary artery lesions before and 12h after PCI. All patients (n=38) had one or more CV risk factors. Ten patients presented with acute coronary syndrome (PCI(ACS)), and the rest (n=20) underwent elective PCI (PCI(Elect)). Despite the presence of an acute coronary syndrome, patients in the PCI(ACS) group did not present with increased EPC-CFU compared with either the PCI(Elect) or control groups (P>0.05). In addition, EPC-CFU (colonies/ml blood) increased significantly in the PCI(Elect) group after stent placement (11.8+1.6 before versus 16.5+1.9 after, P=0.0009), while in contrast, PCI did not stimulate EPC mobilization in patients in the PCI(ACS) group (9.6+3.2 before versus 6.5+1.8, P=0.20). We found a higher presenting vascular endothelial growth factor (VEGF) level in the PCI(Elect) group compared to PCI(ACS) (78.7+25.2 versus 15.3+7.9 pg/ml blood, P=0.02). However, VEGF levels increased after PCI only in the PCI(ACS) group (15.3+7.9 to 133.3+27.5 pg/ml, P=0.003) and not in the PCI(Elect) group (78.7+25.2 to 79.7+12.2 pg/ml, P=0.97)., Conclusion: Our findings suggest that focal coronary endothelial injury as a result of PCI triggers early mobilization of EPC into the peripheral circulation in patients presenting for an elective PCI, without a corresponding rise in VEGF levels. In contrast, patients with an acute coronary syndrome fail to respond to PCI with early EPC mobilization despite a significant rise in VEGF. The results of the present study may suggest a novel mechanism for early EPC augmentation after PCI.