The influence of concurrent cognitive tasks on motor performance in people with traumatic brain injury: a pilot study.

BACKGROUND: Performing dual-tasks is often required for completing activities of daily living. Limited research investigated the effects of dual-tasking on gait in people with Traumatic Brain Injury (TBI). PURPOSE: To investigate the effects of cognitive tasks on gait in people with TBI Methods: Seven individuals with TBI and nine controls completed walking under three conditions; usual walking, walking with questions and answers, and walking with word generation while 3D motion analysis system captured gait. RESULTS: Significant group x condition interactions were found in which TBI group showed greater changes in speed (p < .01), cadence (p = .07), and ankle kinematics (p = .03) as cognitive task became more complex from usual walking to walking with word generation. TBI group decreased speed (p = .02), stride length (p = .01), and hip kinematics (p = .03) as concurrent task became more complex. The control showed decreases in speed (p = .01), stride length (p = .01), and joint kinematics in the hip (p = .03) and knee (p = .01) as the complexity of concurrent cognitive task increased. CONCLUSION: People with TBI have greater difficulty walking with a cognitive task and show greater compromises in gait performance as the task complexity increases when compared to those without TBI. Clinicians should consider the use of progression in cognitive tasks for dual-task gait training.

Comparison of Treadmill and Overground Walking in Children and Adolescents.

The primary purpose of this study was to compare biomechanical gait variables and perceived gait velocity between overground and treadmill walking conditions among typically developing children and adolescents. Twenty children and adolescents (Mage = 11.4, SD = 2.9 years) walked overground and on a treadmill at a matched comfortable walking speed while a 3-D motion analysis system captured spatiotemporal and kinematic gait parameters. In order to compare perceived gait velocities, we acquired data at self-selected comfortable and fastest walking speeds. Paired t-tests comparing the children's speed and gait in these two different walking conditions revealed significantly higher cadence (p < .001) and shorter stride length (p < .002), during treadmill versus overground walking. In addition, treadmill walking showed statistically significant differences in joint kinematics of ankle excursion and pelvic rotation excursions (p < .001). Participants chose slower speeds on the treadmill than for overground walking when they were asked to select their comfortable and fastest walking speeds (p < .001). Our findings suggest that these differences between treadmill and overground walking in cadence, stride length, and perceived gait velocity should be considered whenever a treadmill is used for gait research within the pediatric population. However, the differences we found in gait kinematics between these two walking conditions appear to be relatively trivial and fell within the common error range of kinematic analysis.

A comparison of using the DSM-5 and MABC-2 for estimating the developmental coordination disorder prevalence in Korean children.

BACKGROUND: Previous literature has shown inconsistency in the prevalence of developmental coordination disorder (DCD). The Movement Assessment Battery for Children, Second Edition (MABC-2) is often used for DCD prevalence studies, although the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) recommends four criteria. AIMS: The purpose of this study was to compare the prevalence of DCD in Korean children using the DSM-5 and MABC-2. METHODS: A total of 548 Korean elementary school students (mean age: 8.5 years ± 4.5 months) completed this study procedure. All four criteria defined by the DSM-5 were used to classify children with DCD. MABC-2 test scores were used to classify students into four subgroups: high-risk DCD, mild-risk DCD, probable DCD and typical development. RESULTS: Cohen's kappa revealed that the estimates of DCD prevalence were not significantly different between MABC-2 and DSM-5. When DSM-5 criteria were applied, 60 children out of 548 were classified as probable DCD (10.94%) compared to 70 children with probable DCD (12.77%) when MABC-2 was used. CONCLUSIONS: DCD prevalence based on DSM-5 is not significantly different from MABC-2, though it tends to estimate less than MABC-2. Future studies should consider our findings when selecting an assessment tool.

Factors associated with quality of life and functional disability among rheumatoid arthritis patients treated with disease-modifying anti-rheumatic drugs for at least 6 months.

AIM: To determine characteristics of rheumatoid arthritis (RA) patients in Korea using disease-modifying anti-rheumatic drugs (DMARDs) for at least 6 months, and to identify factors associated with poor health-related outcomes. METHOD: A total of 2000 RA patients aged > 20 years, treated with DMARDs for at least 6 months, and signed informed consent, were enrolled in this non-interventional, multicenter, cross-sectional observational study from December 2012 to June 2013. Health-related quality of life (HRQoL) was measured using EuroQuol 5D (EQ-5D) and functional disability was measured using the Korean Health Assessment Questionnaire (KHAQ). Univariate and multivariate linear regression analyses were used to determine the association between patient characteristics and patient-reported outcomes (PROs). RESULTS: Of all RA patients, 84% were female, patients with low Disease Activity Score of 28 joints erythrocyte sedimentation rate (DAS-28-ESR < 3.2) was 54%, while moderate (DAS-28-ESR 3.2-5.1) and high disease activity score (DAS-28-ESR > 5.1) were 38% and 7.6%, respectively. Mean EQ-5D index score and KHAQ score were 0.6 ± 0.28 and 0.7 ± 0.67, respectively. In multivariate analysis with both PROs, average HRQoL and functional disability score appeared to be worse in persons with older age compared to younger age (P < 0.001), and worse in females compared to males (P < 0.001). Compared to patients having lower DAS (< 3.2), those with moderate and highest DAS (3.2-5.1 and > 5.1) had worse outcome measures (P < 0.001). CONCLUSION: In this study, higher DAS was one of the most influential factors for poor PROs among all other factors. Therefore, we could suggest appropriate treatment approaches according to DAS along with other significantly associated factors with PROs in the early stage of RA.

Coenzyme Q10 suppresses Th17 cells and osteoclast differentiation and ameliorates experimental autoimmune arthritis mice.

Coenzyme Q10 (CoQ10) is a lipid-soluble antioxidant synthesized in human body. This enzyme promotes immune system function and can be used as a dietary supplement. Rheumatoid arthritis (RA) is an autoimmune disease leading to chronic joint inflammation. RA results in severe destruction of cartilage and disability. This study aimed to investigate the effect of CoQ10 on inflammation and Th17 cell proliferation on an experimental rheumatoid arthritis (RA) mice model. CoQ10 or cotton seed oil as control was orally administrated once a day for seven weeks to mice with zymosan-induced arthritis (ZIA). Histological analysis of the joints was conducted using immunohistochemistry. Germinal center (GC) B cells, Th17 cells and Treg cells of the spleen tissue were examined by confocal microscopy staining. mRNA expression was measured by real-time PCR and protein levels were estimated by enzyme-linked immunosorbent assay (ELISA). Flow cytometric analysis (FACS) was used to evaluate Th17 cells and Treg cells. CoQ10 mitigated the severity of ZIA and decreased serum immunoglobulin concentrations. CoQ10 also reduced RANKL-induced osteoclastogenesis, inflammatory mediators and oxidant factors. Th17/Treg axis was reciprocally controlled by CoQ10 treatment. Moreover, CoQ10 treatment on normal mouse and human cells cultured in Th17 conditions decreased the number of Th17 cells and enhanced the number of Treg cells. CoQ10 alleviates arthritis in mice with ZIA declining inflammation, Th17 cells and osteoclast differentiation. These findings suggest that CoQ10 can be a potential therapeutic substance for RA.

Intravenous immunoglobulin attenuates experimental autoimmune arthritis by inducing reciprocal regulation of Th17 and Treg cells in an interleukin-10-dependent manner.

OBJECTIVE: Intravenous immunoglobulin (IVIG) is used as a therapeutic agent in various autoimmune diseases. The aims of this study were to investigate the therapeutic effects of IVIG on collagen-induced arthritis (CIA) and identify the mechanism responsible for any therapeutic effects. METHODS: IVIG was administered to mice with CIA, and the in vivo effects were determined. Th17 and Treg cell frequencies were analyzed by flow cytometry, and cytokine levels in the supernatant were measured by enzyme-linked immunosorbent assay. Subpopulations of T cells and B cells in the spleen were assessed by confocal microscopy. RESULTS: The arthritis severity score and incidence of arthritis were lower in mice treated with IVIG compared with untreated mice. Histopathologic analysis showed less joint damage in mice treated with IVIG. The expression of proinflammatory cytokines, specific type II collagen antibodies, and osteoclast markers was significantly reduced in mice treated with IVIG. Administration of IVIG induced increased FoxP3 expression and inhibited Th17 cell development. The number of FoxP3+ Treg cells was increased, and the number of Th17 cells was decreased in the spleens of mice treated with IVIG. The number of FoxP3+ follicular helper T cells was increased, and subsequent maturation of germinal center B cells was inhibited by IVIG. In addition, IVIG up-regulated interleukin-10 (IL-10) and Fcγ receptor IIB expression. The treatment effects of IVIG on arthritis were lost in IL-10-knockout mice. CONCLUSION: These results showed that IVIG has therapeutic effects by modulating CD4+ T cell differentiation. The therapeutic effects of IVIG are dependent on IL-10.

Clinical and radiographic features of adult-onset ankylosing spondylitis in Korean patients: comparisons between males and females.

The objective of this study was to investigate clinical and radiographic features and gender differences in Korean patients with adult-onset ankylosing spondylitis. Multicenter cross-sectional studies were conducted in the rheumatology clinics of 13 Korean tertiary referral hospitals. All patients had a confirmed diagnosis of ankylosing spondylitis according to the modified New York criteria. Clinical, laboratory, and radiographic features were evaluated and disease activities were assessed using the Bath ankylosing spondylitis disease activity index. Five hundred and five patients were recruited. The male to female ratio was 6.1:1. Average age at symptom onset was 25.4+/-8.9 yr and average disease duration was 9.6+/-6.8 yr. Males manifested symptoms at a significantly earlier age. HLA-B27 was more frequently positive in males. Hips were more commonly affected in males, and knees in females. When spinal mobility was measured using tragus-to-wall distance and the modified Schober's test, females had significantly better results. Radiographic spinal changes, including bamboo spine and syndesmophytes, were more common in males after adjustment of confounding factors. In conclusion, we observed significant gender differences in radiographic spinal involvement as well as other clinical manifestations among Korea patients with adult-onset ankylosing spondylitis. These findings may influence the timing of the diagnosis and the choice of treatment.

Indoleamine 2,3-dioxygenase-expressing dendritic cells are involved in the generation of CD4+CD25+ regulatory T cells in Peyer's patches in an orally tolerized, collagen-induced arthritis mouse model.

INTRODUCTION: The present study was devised to understand the role of systemic indoleamine 2,3-dioxygenase (IDO) in the tolerance induction for orally tolerized mice in collagen-induced arthritis (CIA). We examined whether IDO-expressing dendritic cells (DCs) are involved in the generation of CD4+CD25+ regulatory T cells during the induction of oral tolerance in a murine CIA model. METHODS: Type II collagen was fed six times to DBA/1 mice beginning 2 weeks before immunization, and the effect on arthritis was assessed. To examine the IDO expression, the DCs of messenger RNA and protein were analyzed by RT-PCR and Flow cytometry. In addition, a proliferative response assay was also carried out to determine the suppressive effects of DCs through IDO. The ability of DCs expressing IDO to induce CD4+CD25+ T regulatory cells was examined. RESULTS: CD11c+ DCs in Peyer's patches from orally tolerized mice expressed a higher level of IDO than DCs from nontolerized CIA mice. IDO-expressing CD11c+ DCs were involved in the suppression of type II collagen-specific T-cell proliferation and in the downregulation of proinflammatory T helper 1 cytokine production. The suppressive effect of IDO-expressing CD11c+ DCs was mediated by Foxp3+CD4+CD25+ regulatory T cells. CONCLUSION: Our data suggest that tolerogenic CD11c+ DCs are closely linked with the induction of oral tolerance through an IDO-dependent mechanism and that this pathway may provide a new therapeutic modality to treat autoimmune arthritis.

Size fractionation of marine sediments by pinched inlet gravitational split-flow thin fractionation and the study of size dependent PCDD/Fs concentrations from different bay areas.

Pinched inlet gravitational split-flow thin fractionation (PI-GSF) has been applied to the continuous size fractionation of marine sediments in order to study the difference in sediment size distribution and the concentration of PCDD/Fs contained in different particle sizes. A PI-GSF channel, known to improve the separation efficiency by reducing the sample inlet thickness, was utilized to fractionate sediments collected from three different bay areas (Geoje, Ulsan, and Pohang) in Korea into 5 different sub-populations (<2.0, 2.0-5.0, 5.0-10, 10-20, 20-63 microm in diameter). The sorted sediment fractions from PI-GSF were examined using electron microscopy to obtain size distribution and the results showed a variation in particle size distribution between bay areas. When the collected particle fractions were examined for size dependent levels of PCDD/Fs, the concentrations of total PCDD/Fs were shown to be much greater for samples collected close to heavy industry complexes than sediments from bay areas without major industry.

Induction of IL-10-producing CD4+CD25+ T cells in animal model of collagen-induced arthritis by oral administration of type II collagen.

Induction of oral tolerance has long been considered a promising approach to the treatment of chronic autoimmune diseases, including rheumatoid arthritis (RA). Oral administration of type II collagen (CII) has been proven to improve signs and symptoms in RA patients without troublesome toxicity. To investigate the mechanism of immune suppression mediated by orally administered antigen, we examined changes in serum IgG subtypes and T-cell proliferative responses to CII, and generation of IL-10-producing CD4+CD25+ T-cell subsets in an animal model of collagen-induced arthritis (CIA). We found that joint inflammation in CIA mice peaked at 5 weeks after primary immunization with CII, which was significantly less in mice tolerized by repeated oral feeding of CII before CIA induction. Mice that had been fed with CII also exhibited increased serum IgG1 and decreased serum IgG2a as compared with nontolerized CIA animals. The T-cell proliferative response to CII was suppressed in lymph nodes of tolerized mice also. Production of IL-10 and of transforming growth factor-beta from mononuclear lymphocytes was increased in the tolerized animals, and CD4+ T cells isolated from tolerized mice did not respond with induction of IFN-gamma when stimulated in vitro with CII. We also observed greater induction of IL-10-producing CD4+CD25+ subsets among CII-stimulated splenic T cells from tolerized mice. These data suggest that when these IL-10-producing CD4+CD25+ T cells encounter CII antigen in affected joints they become activated to exert an anti-inflammatory effect.

Increase of cyclooxygenase-2 expression by interleukin 15 in rheumatoid synoviocytes.

OBJECTIVE: To determine the effect of interleukin 15 (IL-15) on cyclooxygenase-2 (COX-2) expression in rheumatoid synoviocytes. METHODS: Fibroblast-like synoviocytes (FLS) were prepared from the synovial tissues of patients with rheumatoid arthritis (RA) and cultured in the presence of IL-15. Levels of COX-2 mRNA and protein expression were determined by reverse transcription-polymerase chain reaction and Western blot, respectively. ELISA was used to measure concentrations of IL-1beta, tumor necrosis factor-a (TNF-a), and prostaglandin E2 (PGE2) in the culture supernatants. RESULTS: IL-15 dose-dependently increased COX-2 mRNA and protein expression in FLS, but not the COX-1 mRNA level. Both IL-1beta and TNF-a upregulated COX-2 mRNA comparably to IL-15, but neither IL-2 nor interferon-g had any effect on the COX-2 mRNA level. Treatment with anti-IL-1beta or anti-TNF-a antibodies partially reduced the IL-15-stimulated COX-2 mRNA expression, suggesting that these cytokines may take part in modulating COX-2 by IL-15. Dexamethasone and pyrolidine dithiocarbamate, but not curcumin, completely blocked the IL-15-induced upregulation of COX-2 mRNA. A gel mobility shift assay revealed that nuclear factor-kB (NF-kB) was one of the major signal molecules to mediate IL-15-induced COX-2 upregulation. The increase of COX-2 by IL-15 is PGE2-dependent because exogenous PGE2 reversed the suppressive effect of NS-398, a selective COX-2 inhibitor, on COX-2 mRNA and protein expression. CONCLUSION: This study confirms the effect of IL-15 on upregulation of COX-2 in a PGE2-dependent manner. The activation of NF-kB bound to the COX-2 promoter appears to be a downstream target of IL-15 stimulation in FLS, exerted either directly or through the increase in IL-1beta and TNF-a production.