Five-Session Dual-Transcranial Direct Current Stimulation With Task-Specific Training Does Not Improve Gait and Lower Limb Performance Over Training Alone in Subacute Stroke: A Pilot Randomized Controlled Trial

ObjectiveTo determine the effect of five-session dual-transcranial direct current stimulation (dual-tDCS) combined with task-specific training on gait and lower limb motor performance in individuals with subacute stroke.Materials and MethodsTwenty-five participants who had a stroke in the subacute phase with mild motor impairment were recruited, randomized, and allocated into two groups. The active group (n = 13) received dual-tDCS with anodal over the lesioned hemisphere M1 and cathodal over the nonlesioned hemisphere, at 2 mA for 20 min before training for five consecutive days, while the sham group (n = 12) received sham mode before training. Gait speed as a primary outcome, temporospatial gait variables, lower-limb functional tasks (sit-to-stand and walking mobility), and muscle strength as secondary outcomes were collected at preintervention and postintervention (day 5), one-week follow-up, and one-month follow-up.ResultsThe primary outcome and most of the secondary outcomes were improved in both groups, with no significant difference between the two groups, and most of the results indicated small to moderate effect sizes of active tDCS compared to sham tDCS.ConclusionThe combined intervention showed no benefit over training alone in improving gait variables and lower-limb performance. However, some performances were saturated at some point, as moderate to high function participants were recruited in the present study. Future studies should consider recruiting participants with more varied motor impairment levels and may need to determine the optimal stimulation protocols and parameters to improve gait and lower-limb performance.     

Effect of speed on the upper and contralateral lower limb coordination during gait in individuals with stroke

The purposes of this study were to investigate the upper and contralateral lower limb coordination and to study the effect of speed on the upper and contralateral lower limb coordination in individuals with stroke and control groups. Thirty individuals with stroke who were able to walk independently without using any assistive devices and 30 control individuals were recruited for the study. Upper and contralateral lower limb coordination was analyzed using the shoulder and contralateral hip displacements in the sagittal plane. All data were analyzed by three-dimensional gait analysis. Results demonstrated high degrees of coordination in the upper and contralateral lower limbs of the controls and in the unaffected upper and affected lower limbs of individuals with stroke. Gait speed was found to be associated with the upper and contralateral lower limb coordination in individuals with stroke but not in the controls. The findings implied that the affected upper limb plays an important role for improving gait coordination and is necessary for gait performance in individuals with stroke. Thus, health professionals should exercise the affected arm to increase efficiency of walking in individuals with stroke.     

Impact on Participation and Autonomy Questionnaire: Psychometric Properties of the Thai Version

[Purpose] The present study aimed to cross-culturally translate and evaluate the reliability and validity of the Thai version of the Impact on Participation and Autonomy (IPA) in persons with spinal cord injury (SCI). [Subjects] One hundred and thirty-nine persons with SCI who lived in the community were recruited for this study. [Methods] The IPA was translated following the guideline for cross-cultural adaptation of self-report measures. The reliability and validity was examined in 139 persons with SCI. For the test-retest reliability, 30 participants completed the Thai version of the IPA twice with a 2-week interval. [Results] The translated questionnaire and its items had moderate to good reliability, with the ICC_(3,1) ranging from 0.76 to 0.93. The internal consistency for all domains was high, with Cronbach''s alpha ranging from 0.86 to 0.90. The convergent validity, discriminant validity, and construct validity were supported. [Conclusion] The Thai version of the IPA is a reliable and valid instrument for assessing the level of community participation in Thai persons with spinal cord injury.Key words: Assessment, Community participation, Spinal cord injury     

Cytolethal Distending Toxin from Aggregatibacter actinomycetemcomitans Induces DNA Damage,S/G2 Cell Cycle Arrest,and Caspase- Independent Death in a Saccharomyces cerevisiae Model

Cytolethal distending toxin (CDT) is a bacterial toxin that induces G₂/M cell cycle arrest, cell distension, and/or apoptosis in mammalian cells. It is produced by several Gram-negative species and may contribute to their pathogenicity. The catalytic subunit CdtB has homology with DNase I and may act as a genotoxin. However, the mechanism by which CdtB leads to cell death is not yet clearly understood. Here, we used Saccharomyces cerevisiae as a model to study the molecular pathways involved in the function of CdtB from Aggregatibacter actinomycetemcomitans, a cause of aggressive periodontitis. We show that A. actinomycetemcomitans CdtB (AaCdtB) expression induces S/G₂ arrest and death in a DNase-catalytic residue and nuclear localization-dependent manner in haploid yeasts. Yeast strains defective in homologous recombination (HR) repair, but not other DNA repair pathways, are hypersensitive to AaCdtB, suggesting that HR is required for survival upon CdtB expression. In addition, yeast does not harbor the substrate for the other activity proposed for CdtB function, which is phosphatidylinositol-3,4,5-triphosphate phosphatase. Thus, these results suggest that direct DNA-damaging activity alone is sufficient for CdtB toxicity. To investigate how CdtB induces cell death, we examined the effect of CdtB in yeast strains with mutations in apoptotic regulators. Our results suggest that yeast death occurs independently of the yeast metacaspase gene YCA1 and the apoptosis-inducing factor AIF1 but is partially dependent on histone H2B serine 10 phosphorylation. Therefore, we report here the evidence that AaCdtB causes DNA damage that leads to nonapoptotic death in yeast and the first mutation that confers resistance to CdtB.Aggregatibacter actinomycetemcomitans is a Gram-negative bacterial species that has been implicated in the pathogenesis of periodontal diseases, especially the aggressive forms (12). This bacterium possesses many virulence factors and produces several toxins, one of which is cytolethal distending toxin (CDT). CDT induces cell distension, cell cycle arrest, and death in mammalian host cells. It is produced by several pathogenic bacterial species, including Escherichia coli, Campylobacter jejuni, Haemophilus ducreyi, Shigella dysenteriae, Helicobacter hepaticus, Salmonella enterica serovar Typhi, and others (16, 28). A. actinomycetemcomitans CDT (AaCDT) has been shown to induce G₂ cell cycle arrest and/or apoptosis in many cell types, including lymphocytes (16, 26, 28, 34). Therefore, this toxin may play a role in bacterial pathogenicity via immune system evasion. Moreover, the ability to induce host cell death could lead to tissue destruction and delayed healing. In the case of periodontitis, this could lead to eventual tooth loss. Clinical isolates of A. actinomycetemcomitans from patients with periodontitis show high frequency of CDT production, further suggesting its role in the pathogenesis of the disease (43).The genes that encode the 3 subunits of CDT, cdtA, -B, and -C, are located in the cdt locus (40). Structural and functional studies suggested that the 3 subunits form a heterotrimer of CDT holotoxin and that all subunits are required for full activity (15, 31, 33). CdtB is the enzymatically active subunit, while CdtA and CdtC are necessary for the delivery of CdtB into host cells (16). CdtB has only limited homology with DNase I, but the residues important in the catalytic activity are well conserved. DNase activity is detected in crude CDT preparation in vitro, and mutations of the residues corresponding to the DNase-active site abolish the cytotoxic effects on cultured cells (8, 14). This suggests that the DNase activity of CdtB is essential for its cytotoxicity. Nevertheless, CdtB has also been proposed to induce cell cycle arrest through its function as a phosphatidylinositol-3,4,5-triphosphate phosphatase (35). Since the residues important for both DNase and phosphatase activities largely overlap, this raises a question as to which activity is the major contributor to the effects of CDT.Budding yeast (Saccharomyces cerevisiae) has served as an excellent model organism for the study of many biological processes, including cell cycle regulation, DNA repair, and even cell death (21). In recent years, yeast has also proven to be a useful surrogate host for the characterization of several bacterial effectors that target conserved biological processes in eukaryotic host cells (6, 39). Therefore, yeast appears to be a particularly interesting model for the elucidation of the effects of CDT on cellular processes that regulate cell cycle and death. Campylobacter jejuni CdtB (CjCdtB) has been shown to induce G₂ cell cycle arrest, chromosome degradation, and loss of viability upon expression in a yeast model (10). Many genomic tools available in yeast also provide an opportunity to analyze the effects of CDT in a genome-wide fashion (13). Previous studies of yeast suggest that CdtB likely acts as a genotoxin. However, the mechanism by which CdtB induces cell cycle arrest and death has not yet been fully elucidated. Here, we used yeast as a model to characterize the mechanisms by which AaCdtB expression induces cell death.     

Responsiveness of pain, active range of motion, and disability in patients with acute nonspecific low back pain

Many parameters are now used for investigations in clinical settings, such as pain, active range of motion (AROM), and disability, but it is not yet known which parameters are responsive in patients with acute nonspecific low back pain (LBP). This study aimed to investigate the responsiveness of pain, AROM, and disability in patients with acute nonspecific LBP. Fifty subjects were assessed for pain, AROM, and disability at baseline and after 6 weeks. The effect size (ES) was calculated for each parameter. Also, patient’s perception of change was collected after 6 weeks for correlating it with change scores for each parameter. The most responsive parameter for detecting the change in patients with acute nonspecific LBP was pain (ES, 1.57) and disability (ES, 0.93). However, AROM was proved to be less responsive. This study indicated that pain and disability were responsive in detecting the changes in patients with acute nonspecific LBP over time.     

A single neonatal exposure to aflatoxin b1 induces prolonged genetic damage in two Loci of mouse liver

Aflatoxin B (1) (AFB(1)) is a risk factor for hepatocellular carcinoma in humans. Infant, but not adult, mice are sensitive to AFB(1)-induced liver carcinogenesis; a single dose during the neonatal period leads to hepatocellular carcinoma in adulthood. Earlier work defined the mutational spectrum in the gpt gene of gpt delta B6C3F1 mice 3 weeks after exposure to aflatoxin. In the present study, we examined the gpt spectrum 10 weeks postdosing and expanded the study to examine, at 3 and 10 weeks, the spectrum at a second locus, the red/gam genes of the mouse λEG10 transgene. Whereas the gpt locus is typically used to define local base changes, the red/gam genes, via the Spi(-) assay, often are used to detect more global mutations such as large deletions and rearrangements. Three weeks after dosing with AFB(1), there was a 10-fold increase over the control in the Spi(-) mutant fraction (MF) in liver DNA; after 10 weeks, a further increase was observed. The MF in the gpt gene was also increased at 10 weeks compared with the MF at 3 weeks. No gender-specific differences were found in the Spi(-) or gpt MFs. Whereas Spi(-) mutations often signal large genetic changes, they did not in this specific case. The Spi(-) spectrum was dominated by GC to TA transversions, with one exceptionally strong hotspot at position 314. Using two genetic loci, the data show a strong preference for the induction of GC to TA mutations in mice, which is the dominant mutation seen in people exposed to aflatoxin.     

Different Sagittal Angles and Moments of Lower Extremity Joints during Single-leg Jump Landing among Various Directions in Basketball and Volleyball Athletes

[Purpose] The purpose of this study was to assess the sagittal angles and moments of lower extremity joints during single-leg jump landing in various directions. [Subjects] Eighteen male athletes participated in the study. [Methods] Participants were asked to perform single-leg jump-landing tests in four directions. Angles and net joint moments of lower extremity joints in the sagittal plane were investigated during jump-landing tests from a 30-cm-high platform with a Vicon™ motion system. The data were analyzed with one-way repeated measures ANOVA. [Results] The results showed that knee joint flexion increased and hip joint flexion decreased at foot contact. In peak angle during landing, increasing ankle dorsiflexion and decreasing hip flexion were noted. In addition, an increase in ankle plantarflexor moment occurred. [Conclusion] Adjusting the dorsiflexion angle and plantarflexor moment during landing might be the dominant strategy of athletes responding to different directions of jump landing. Decreasing hip flexion during landing is associated with a stiff landing. Sport clinicians and athletes should focus on increasing knee and hip flexion angles, a soft landing technique, in diagonal and lateral directions to reduce risk of injury.Key words: Jump landing, Joint angles, Joint moments     

Effects of Strength and Endurance Training of Superficial and Deep Neck Muscles on Muscle Activities and Pain Levels of Females with Chronic Neck Pain

[Purpose] To compare muscle activities and pain levels of females with chronic neck pain receiving different exercise programs. [Subjects and Methods] One hundred females with chronic neck pain participated in this study. They were randomly allocated into 4 groups (n = 25) on the basis of the exercises performed as follows: strength-endurance exercise, craniocervical flexion exercise, combination of strength-endurance and craniocervical flexion exercise and control groups. Pain, disability levels and changes in the muscle activities of the cervical erector spinae (CE), sternocleidomastoid (SCM), anterior scalenes (AS) and upper trapezius (UT) muscles were evaluated before and after the interventions. [Results] After 12 weeks of exercise intervention, all three exercise groups showed improvements in pain and disability. The muscle activities during the typing task were significantly different from the control group in all three exercise groups for all muscles except those of the extensor muscles in the craniocervical flexion exercise group. [Conclusion] The results of this study indicate that exercises for the cervical muscles improve pain and disability. The exercise programs reduced the activities of almost all cervical muscles.Key words: Chronic neck pain, Exercise, Muscle activity