31 research outputs found

    Atlas-based quantification of DTI measures in a typically developing pediatric spinal cord

    Get PDF
    BACKGROUND AND PURPOSE: Multi-parametric MRI, provides a variety of biomarkers sensitive to white matter integrity, However, spinal cord MRI data in pediatrics is rare compared to adults. The purpose of this work was 3-fold: 1) to develop a processing pipeline for atlasbased generation of the typically developing pediatric spinal cord WM tracts, 2) to derive atlas-based normative values of the DTI indices for various WM pathways, and 3) to investigate age-related changes in the obtained normative DTI indices along the extracted tracts. MATERIALS AND METHODS: DTI scans of 30 typically developing subjects (age range, 6–16 years) were acquired on a 3T MR imaging scanner. The data were registered to the PAM50 template in the Spinal Cord Toolbox. Next, the DTI indices for various WM regions were extracted at a single section centered at the C3 vertebral body in all the 30 subjects. Finally, an ANOVA test was performed to examine the effects of the following: 1) laterality, 2) functionality, and 3) age, with DTI-derived indices in 34 extracted WM regions. RESULTS: A postprocessing pipeline was developed and validated to delineate pediatric spinal cord WM tracts. The results of ANOVA on fractional anisotropy values showed no effect for laterality (P ¼ .72) but an effect for functionality (P , .001) when comparing the 30 primary WM labels. There was a significant (P , .05) effect of age and maturity of the left spinothalamic tract on mean diffusivity, radial diffusivity, and axial diffusivity values. CONCLUSIONS: The proposed automated pipeline in this study incorporates unique postprocessing steps followed by template registration and quantification of DTI metrics using atlas-based regions. This method eliminates the need for manual ROI analysis of WM tracts and, therefore, increases the accuracy and speed of the measurements

    Quantitative gait and balance outcomes for ataxia trials: consensus recommendations by the Ataxia Global Initiative Working Group on Digital-Motor Biomarkers

    Get PDF
    With disease-modifying drugs on the horizon for degenerative ataxias, ecologically valid, finely granulated, digital health measures are highly warranted to augment clinical and patient-reported outcome measures. Gait and balance disturbances most often present as the first signs of degenerative cerebellar ataxia and are the most reported disabling features in disease progression. Thus, digital gait and balance measures constitute promising and relevant performance outcomes for clinical trials.This narrative review with embedded consensus will describe evidence for the sensitivity of digital gait and balance measures for evaluating ataxia severity and progression, propose a consensus protocol for establishing gait and balance metrics in natural history studies and clinical trials, and discuss relevant issues for their use as performance outcomes

    Low-cost, biodegradable and highly effective adsorbents for batch and column fixed bed adsorption processes of methylene blue

    No full text
    This work reports the preparation of low-cost and ecological bioadsorbents and study of their adsorption properties in the elimination of methylene blue dye (MB) from wastewater Unmodified citrus peels (UCP) and unmodified citrus peels encapsulated with calcium alginate (UCP/A) were characterized by elementary analysis, FTIR, DRX, SEM. Isotherm studies in the batch system were investigated and the maximum adsorbed amounts were found to be 185.83 and 964.54 mg/g respectively for UCP and UCP/A. The Langmuir model fitted well experimental data of isotherms with high coefficient correlation R-2, low RMSE and chi(2). Fixed bed adsorption was studied with operational conditions such as the bed height, MB flow rate and MB inlet concentration to test the performance of column. The breakthrough curves and the break time increase with the decrease of the rate flow and with the increased bed height. The highest bed capacity of 31.45 mg/g and highest percentage of MB solution treated (93.6%) was obtained using 2 mL/min rate flow, 200 mg/L inlet MB concentration and 3.5 cm (4 g) bed height. The breakthrough curves were fitted using Thomas and Yoon and Nelson models. The behaviors of the breakthrough and the R-2 founded by these models are high (R-2 > 0.97) which shows good applicability of models

    Bone health in urban midlife Malaysian women: risk factors and prevention

    No full text
    The aim of this study was to identify risk factors associated with osteoporosis in urban midlife Malaysian women and to assess the effectiveness of lifestyle intervention in bone loss prevention with hormone replacement therapy (HRT) as a positive control. A total of 514 disease-free, uterus-intact, non-HRT-using women aged 45 years and older were recruited into the study. After initial bone mineral density (BMD) assessments, they were randomized into three groups: GI (control), G2 (lifestyle intervention), and G3 (lifestyle intervention with HRT). The study group was composed of 67.5% Chinese, 27.8% Malay, and 4.2% Indians with a mean age of 51.07+/-5.28 years. Two-fifths were postmenopausal, and the prevalence of osteoporosis was 24.1%, seen predominantly at the hip. Postmenopausal women had significantly lower mean BMD and a higher incidence of osteoporosis compared with the premenopausal women, 42.1% vs. 11.1% (p<0.0005). A lower incidence of osteoporosis was found in women who took calcium supplementation regularly as opposed to those who do not, 18.7% vs. 29.3% (p=0.036). Age and a greater postmenopausal duration showed a significant negative association with BMD, whereas higher family income, weight, body mass index, and waist and hip circumference were positively correlated. After 18-20 months, the effect of intervention was assessed based on BMD values of 279 women at baseline and after intervention. Lifestyle intervention alone was effective in premenopausal women, preventing over 90% of spinal bone loss compared with the controls, who lost 11.6% (0.046 g/cm2) bone mass with similar losses of hip bone, 2.0% (0.026 g/cm2) vs. 1.5% (0.020 g/cm2). Premenopausal women on HRT also showed a substantial decrease in spine and hip BMD, 18.6% (0.081 g/cm2) and 9.0% (0.122 g/cm2), respectively. The lifestyle intervention program retarded postmenopausal bone loss by 21% and 37% compared with controls, who lost 9.6% (0.141 g/cm2) and 6.0% (0.138 g/cm2) bone mass at the spine and hip. In comparison, lifestyle intervention with HRT increased postmenopausal BMD by 12.7% (0.216 g/cm2) at the spine and 1.9% (0.042 g/cm2) at the hip. The changes in hip BMD were influenced by current age, ethnicity, and income, while intervention had the strongest effect on spine BMD changes. In conclusion, lifestyle intervention prevented spinal bone loss in premenopausal women and retarded postmenopausal spine and hip bone loss compared with controls. The benefits of physical activity on spine and hip BMD highlight its potential as a safe and cost-effective alternative to HRT, which is not advocated because of its potential adverse effects

    SARS-CoV-2 and Stroke Characteristics: A Report from the Multinational COVID-19 Stroke Study Group

    Get PDF
    cited By 0BACKGROUND AND PURPOSE: Stroke is reported as a consequence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection in several reports. However, data are sparse regarding the details of these patients in a multinational and large scale. METHODS: We conducted a multinational observational study on features of consecutive acute ischemic stroke, intracranial hemorrhage, and cerebral venous or sinus thrombosis among SARS-CoV-2-infected patients. We further investigated the risk of large vessel occlusion, stroke severity as measured by the National Institutes of Health Stroke Scale, and stroke subtype as measured by the TOAST (Trial of ORG 10172 in Acute Stroke Treatment) criteria among patients with acute ischemic stroke. In addition, we explored the neuroimaging findings, features of patients who were asymptomatic for SARS-CoV-2 infection at stroke onset, and the impact of geographic regions and countries' health expenditure on outcomes. RESULTS: Among the 136 tertiary centers of 32 countries who participated in this study, 71 centers from 17 countries had at least 1 eligible stroke patient. Of 432 patients included, 323 (74.8%) had acute ischemic stroke, 91 (21.1%) intracranial hemorrhage, and 18 (4.2%) cerebral venous or sinus thrombosis. A total of 183 (42.4%) patients were women, 104 (24.1%) patients were CONCLUSIONS: We observed a considerably higher rate of large vessel occlusions, a much lower rate of small vessel occlusion and lacunar infarction, and a considerable number of young stroke when compared with the population studies before the pandemic. The rate of mechanical thrombectomy was significantly lower in countries with lower health expenditures.Peer reviewe
    corecore