Comparison of the effect of weight-bearing and non-weight-bearing positions on knee position sense in patients with chronic stroke

[Purpose] The purpose of this study was to investigate the knee joint proprioception in weight-bearing (WB) and non-weight-bearing (NWB) positions and to study the difference between the methods in chronic stroke patients. [Subjects and Methods] The subjects were 15 stroke patients who were randomly scheduled to perform both positions by a physical therapist not involved in the study. The subjects performed the positions (WB and NWB) based on a randomized controlled cross-sectional design. WB subjects were positioned in one-leg standing to assess the knee joint position sense. NWB subjects were instructed to sit comfortably in a chair and maintain the knees at 90° of flexion with the leg out of the plinth. [Results] The results revealed that the WB position showed a significant difference in knee position sense. The proprioception sense in the WB position was a higher than that in the NWB position. [Conclusion] The knee proprioception of chronic stroke patients differs between the weight-bearing and non-weight-bearing positions.Key words: Knee proprioception, Stroke, Weight bearing     

Acute effects of unilateral whole body vibration training on single leg vertical jump height and symmetry in healthy men

[Purpose] The aim of the present study was to investigate the acute effects of unilateral whole body vibration training on height and symmetry of the single leg vertical jump in healthy men. [Subjects] Thirty males with no history of lower limb dysfunction participated in this study. [Methods] The participants were randomly allocated to one of three groups: the unilateral vibratory stimulation group (n=10), bilateral vibratory stimulation group (n=10), and, no vibratory stimulation group (n=10). The subjects in the unilateral and bilateral stimulation groups participated in one session of whole body vibration training at 26 Hz for 3 min. The no vibratory stimulation group subjects underwent the same training for 3 min without whole body vibration. All participants performed the single leg vertical jump for each lower limb, to account for the strong and weak sides. The single leg vertical jump height and symmetry were measured before and after the intervention. [Results] The single leg vertical jump height of the weak lower limb significantly improved in the unilateral vibratory stimulation group, but not in the other groups. The single leg vertical jump height of the strong lower limb significantly improved in the bilateral vibratory stimulation group, but not in the other groups. The single leg vertical jump symmetry significantly improved in the unilateral vibratory stimulation group, but not in the other groups. [Conclusion] Therefore, the present study found that the effects of whole body vibration training were different depending on the type of application. To improve the single leg vertical jump height in the weak lower limbs as well as limb symmetry, unilateral vibratory stimulation might be more desirable.Key words: Single leg vertical jump, Symmetry, Whole body vibration     

The effects of stepper exercise with visual feedback on strength,walking, and stair climbing in individuals following stroke

[Purpose] This study investigated the effect of stepper exercise with visual feedback on strength, walking, and stair climbing in stroke patients. [Subjects] Twenty-six stroke patients were divided randomly into the stepper exercise with visual feedback group (n = 13) or the stepper exercise group (n = 13). [Methods] Subjects in the experimental group received feedback through the mirror during exercise, while those in the control group performed the exercise without visual feedback; both groups exercised for the 30 min thrice per week for 6 weeks. The hip extensor and knee extensor strength, 10-m walking test results, and 11-step stair climbing test results were evaluated before and after the intervention. [Results] The stepper exercise with visual feedback group showed significantly greater improvement for hip extensor strength and the 10-m walking test. The knee extensor strength and 11-step stair climbing in both groups showed significantly greater improvement after the intervention, but without any significant difference between groups. [Conclusion] The findings of this study indicate that the stepper exercise with visual feedback can help improve the strength of the hip extensor and the 10-m walking test; the stepper exercise alone may also improve the knee extensor strength and stair climbing ability.Key words: Stroke, Stairs, Visual feedback     

Effects of conventional overground gait training and a gait trainer with partial body weight support on spatiotemporal gait parameters of patients after stroke

[Purpose] The purpose of this study was to confirm the effects of both conventional overground gait training (CGT) and a gait trainer with partial body weight support (GTBWS) on spatiotemporal gait parameters of patients with hemiparesis following chronic stroke. [Subjects and Methods] Thirty stroke patients were alternately assigned to one of two treatment groups, and both groups underwent CGT and GTBWS. [Results] The functional ambulation classification on the affected side improved significantly in the CGT and GTBWS groups. Walking speed also improved significantly in both groups. [Conclusion] These results suggest that the GTBWS in company with CGT may be, in part, an effective method of gait training for restoring gait ability in patients after a stroke.Key words: Gait training, Spatiotemporal gait parameters, Stroke patients     

Erythrophagocytosis of Lead-Exposed Erythrocytes by Renal Tubular Cells: Possible Role in Lead-Induced Nephrotoxicity

Background: Nephrotoxicity associated with lead poisoning has been frequently reported in epidemiological studies, but the underlying mechanisms have not been fully described.Objectives: We examined the role of erythrocytes, one of the major lead reservoirs, in lead-associated nephrotoxicity.Methods and results: Co-incubation of lead-exposed human erythrocytes with HK-2 human renal proximal tubular cells resulted in renal tubular cytotoxicity, suggesting a role of erythrocytes in lead-induced nephrotoxicity. Morphological and flow cytometric analyses revealed that HK-2 cells actively phagocytized lead-exposed erythrocytes, which was associated with phosphatidylserine (PS) externalization on the erythrocyte membrane and generation of PS-bearing microvesicles. Increased oxidative stress and up-regulation of nephrotoxic biomarkers, such as NGAL, were observed in HK-2 cells undergoing erythrophagocytosis. Moreover, TGF-β, a marker of fibrosis, was also significantly up-regulated. We examined the significance of erythrophagocytosis in lead-induced nephrotoxicity in rats exposed to lead via drinking water for 12 weeks. We observed iron deposition and generation of oxidative stress in renal tissues of lead-exposed rats, as well as the histopathological alterations such as tubulointerstitial lesions, fibrosis, and up-regulation of KIM-1, NGAL, and TGF-β.Conclusions: Our data strongly suggest that erythrophagocytosis and subsequent iron deposition in renal tubular cells could significantly enhance nephrotoxicity following lead exposure, providing insight on lead-associated kidney damages.Citation: Kwon SY, Bae ON, Noh JY, Kim K, Kang S, Shin YJ, Lim KM, Chung JH. 2015. Erythrophagocytosis of lead-exposed erythrocytes by renal tubular cells: possible role in lead-induced nephrotoxicity. Environ Health Perspect 123:120–127; http://dx.doi.org/10.1289/ehp.1408094     

Nonprogressive Unilateral Intracranial Arteriopathy in Children with Arterial Ischemic Stroke

The nonprogressive unilateral intracranial arteriopathy known as transient (focal) cerebral arteriopathy is not a well-recognized arteriopathy among practitioners of Korea and Japan, although it cannot be easily differentiated from early moyamoya disease. This review summarizes the nomenclature, pathophysiology, diagnostic evaluation, clinico-radiological features, and management of nonprogressive (reversible or stable) unilateral arteriopathy based on the relevant literature and our own experiences. Nonprogressive unilateral arteriopathy should be strongly suspected in children presenting with basal ganglia infarction and arterial beading. The early identification of patients likely to have nonprogressive or progressive arteriopathy would ensure proper management and guide further research for secondary stroke prevention.     

Acute inhibition of a cortical motor area impairs vocal control in singing zebra finches

Genetically targeted approaches that permit acute and reversible manipulation of neuronal circuit activity have enabled an unprecedented understanding of how discrete neuronal circuits control animal behavior. Zebra finch singing behavior has emerged as an excellent model for studying neuronal circuit mechanisms underlying the generation and learning of behavioral motor sequences. We employed a newly developed, reversible, neuronal silencing system in zebra finches to test the hypothesis that ensembles of neurons in the robust nucleus of the arcopallium (RA) control the acoustic structure of specific song parts, but not the timing nor the order of song elements. Subunits of an ivermectin‐gated chloride channel were expressed in a subset of RA neurons, and ligand administration consistently suppressed neuronal excitability. Suppression of activity in a group of RA neurons caused the birds to sing songs with degraded elements, although the order of song elements was unaffected. Furthermore some syllables disappeared in the middle or at the end of song motifs. Thus, our data suggest that generation of specific song parts is controlled by a subset of RA neurons, whereas elements order coordination and timing of whole songs are controlled by a higher premotor area.