310 research outputs found

    Mendelian randomization shows a causal effect of low vitamin D on multiple sclerosis risk.

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    ObjectiveWe sought to estimate the causal effect of low serum 25(OH)D on multiple sclerosis (MS) susceptibility that is not confounded by environmental or lifestyle factors or subject to reverse causality.MethodsWe conducted mendelian randomization (MR) analyses using an instrumental variable (IV) comprising 3 single nucleotide polymorphisms found to be associated with serum 25(OH)D levels at genome-wide significance. We analyzed the effect of the IV on MS risk and both age at onset and disease severity in 2 separate populations using logistic regression models that controlled for sex, year of birth, smoking, education, genetic ancestry, body mass index at age 18-20 years or in 20s, a weighted genetic risk score for 110 known MS-associated variants, and the presence of one or more HLA-DRB1*15:01 alleles.ResultsFindings from MR analyses using the IV showed increasing levels of 25(OH)D are associated with a decreased risk of MS in both populations. In white, non-Hispanic members of Kaiser Permanente Northern California (1,056 MS cases and 9,015 controls), the odds ratio (OR) was 0.79 (p = 0.04, 95% confidence interval (CI): 0.64-0.99). In members of a Swedish population from the Epidemiological Investigation of Multiple Sclerosis and Genes and Environment in Multiple Sclerosis MS case-control studies (6,335 cases and 5,762 controls), the OR was 0.86 (p = 0.03, 95% CI: 0.76-0.98). A meta-analysis of the 2 populations gave a combined OR of 0.85 (p = 0.003, 95% CI: 0.76-0.94). No association was observed for age at onset or disease severity.ConclusionsThese results provide strong evidence that low serum 25(OH)D concentration is a cause of MS, independent of established risk factors

    Reduction of freezing of gait in Parkinson's disease by repetitive robot-assisted treadmill training: a pilot study

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    <p>Abstract</p> <p>Background</p> <p>Parkinson's disease is a chronic, neurodegenerative disease characterized by gait abnormalities. Freezing of gait (FOG), an episodic inability to generate effective stepping, is reported as one of the most disabling and distressing parkinsonian symptoms. While there are no specific therapies to treat FOG, some external physical cues may alleviate these types of motor disruptions. The purpose of this study was to examine the potential effect of continuous physical cueing using robot-assisted sensorimotor gait training on reducing FOG episodes and improving gait.</p> <p>Methods</p> <p>Four individuals with Parkinson's disease and FOG symptoms received ten 30-minute sessions of robot-assisted gait training (Lokomat) to facilitate repetitive, rhythmic, and alternating bilateral lower extremity movements. Outcomes included the FOG-Questionnaire, a clinician-rated video FOG score, spatiotemporal measures of gait, and the Parkinson's Disease Questionnaire-39 quality of life measure.</p> <p>Results</p> <p>All participants showed a reduction in FOG both by self-report and clinician-rated scoring upon completion of training. Improvements were also observed in gait velocity, stride length, rhythmicity, and coordination.</p> <p>Conclusions</p> <p>This pilot study suggests that robot-assisted gait training may be a feasible and effective method of reducing FOG and improving gait. Videotaped scoring of FOG has the potential advantage of providing additional data to complement FOG self-report.</p

    Autonomic nervous system responses to strength training in top-level weight lifters

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    In athletes, spectral analysis of HR variability (HRV) has been shown capable to detect the adaptational changes in sympatho-vagal control attending physical training. So far, studies investigated autonomic nervous system (ANS) changes occurring with endurance training, whereas adaptations to markedly different exercise modes, for example, strength training, have never been investigated. We assessed the changes in cardiac ANS parameters during long-term training in weight lifters of the Italian team preparing for the European Championship, where athletes competed for obtaining the pass for Olympic Games. We investigated nine athletes. Subject trained 3 sessions/day, 6&nbsp;days a week. The intensity of strength exercises varied from 70% to 95% 1 RM. Training load (TL) was calculated as: volume (min)&nbsp; 7&nbsp;intensity (%1RM).All ANS parameters were significantly and highly correlated on an individual basis to the dose of exercise with a second-order regression model (r2 ranged from 0.96 to 0.99; P&nbsp;&lt;&nbsp;0.001). The low-frequency (LF) component of HRV and LF/HF ratio showed an initial increase with the progression of TL and then a decrease, resembling a bell-shaped curve with a minimum at the highest TL. The high-frequency (HF) component of HRV and R-R interval showed a reciprocal pattern, with an initial decrease with progression of TL followed by an increase, resembling an U-shaped curve with a maximum at the highest TL. These adaptations were at the opposite to those previously reported in endurance athletes. These results suggest that in Olympic weight lifters, ANS adaptations to training are dose-related on individual basis and that ANS adaptations are mainly sport-specific

    Autosomal-dominant myopia associated to a novel P4HA2 missense variant and defective collagen hydroxylation

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    We recently described a complex multisystem syndrome in which mild-moderate myopia segregated as an independent trait. A plethora of genes has been related to sporadic and familial myopia. More recently, in Chinese patients severe myopia (MYP25, OMIM:617238) has been linked to mutations in P4HA2 gene. Seven family members complaining of reduced distance vision especially at dusk underwent complete ophthalmological examination. Whole-exome sequencing was performed to identify the gene responsible for myopia in the pedigree. Moderate myopia was diagnosed in the family which was associated to the novel missense variant c.1147A > G p.(Lys383Glu) in the prolyl 4-hydroxylase,alpha-polypeptide 2 (P4HA2) gene, which catalyzes the formation of 4-hydroxyproline residues in the collagen strands. In vitro studies demonstrated P4HA2 mRNA and protein reduced expression level as well as decreased collagen hydroxylation and deposition in mutated fibroblast primary cultures compared to healthy cell lines. This study suggests that P4HA2 mutations may lead to myopic axial elongation of eyeball as a consequence of quantitative and structural alterations of collagen. This is the first confirmatory study which associates a novel dominant missense variant in P4HA2 with myopia in Caucasian patients. Further studies in larger cohorts are advisable to fully clarify genotype-phenotype correlations.We recently described a complex multisystem syndrome in which mild-moderate myopia segregated as an independent trait. A plethora of genes has been related to sporadic and familial myopia. More recently, in Chinese patients severe myopia (MYP25, OMIM:617238) has been linked to mutations in P4HA2 gene. Seven family members complaining of reduced distance vision especially at dusk underwent complete ophthalmological examination. Whole-exome sequencing was performed to identify the gene responsible for myopia in the pedigree. Moderate myopia was diagnosed in the family which was associated to the novel missense variant c.1147A > G p.(Lys383Glu) in the prolyl 4-hydroxylase,alpha-polypeptide 2 (P4HA2) gene, which catalyzes the formation of 4-hydroxyproline residues in the collagen strands. In vitro studies demonstrated P4HA2 mRNA and protein reduced expression level as well as decreased collagen hydroxylation and deposition in mutated fibroblast primary cultures compared to healthy cell lines. This study suggests that P4HA2 mutations may lead to myopic axial elongation of eyeball as a consequence of quantitative and structural alterations of collagen. This is the first confirmatory study which associates a novel dominant missense variant in P4HA2 with myopia in Caucasian patients. Further studies in larger cohorts are advisable to fully clarify genotype-phenotype correlations

    The DAFNEplus programme for sustained type 1 diabetes self management: Intervention development using the Behaviour Change Wheel

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    AIMS: Self-management programmes for type 1 diabetes, such as the UK's Dose Adjustment for Normal Eating (DAFNE), improve short-term clinical outcomes but difficulties maintaining behavioural changes attenuate long-term impact. This study used the Behaviour Change Wheel (BCW) framework to revise the DAFNE intervention to support sustained behaviour change. METHODS: A four-step method was based on the BCW intervention development approach: 1) Identifying self-management behaviours and barriers/enablers to maintaining them via stakeholder consultation and evidence synthesis, and mapping barriers/enablers to the Capability, Opportunity, Motivation-Behaviour (COM-B) model. 2) Specifying behaviour change techniques (BCTs) in the existing DAFNE intervention using the Behaviour Change Techniques Taxonomy (BCTTv1). 3) Identifying additional BCTs to target the barriers/enablers using the BCW and BCTTv1. 4) Parallel stakeholder consultation to generate recommendations for intervention revision. Revised materials were co-designed by stakeholders (diabetologists, psychologists, specialist nurses and dietitians). RESULTS: Thirty-four barriers and five enablers to sustaining self-management post-DAFNE, were identified. The existing DAFNE intervention contained 24 BCTs, which partially addressed the enablers. Twenty-seven BCTs were added, including 'Habit formation', 'Credible source' and 'Conserving mental resources'. Fifteen stakeholder-agreed recommendations for content and delivery were incorporated into the final DAFNEplus intervention, comprising three co-designed components: (1) face-to-face group learning course, (2) individual structured follow-up sessions, (3) technological support, including blood glucose data management. CONCLUSIONS: This method provided a systematic approach to specifying and revising a behaviour change intervention incorporating stakeholder input. The revised DAFNEplus intervention aims to support the maintenance of behavioural changes by targeting barriers and enablers to sustaining self-management behaviours

    Causal Effect of Genetic Variants Associated With Body Mass Index on Multiple Sclerosis Susceptibility.

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    To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked FilesMultiple sclerosis (MS) is an autoimmune disease with both genetic and environmental risk factors. Recent studies indicate that childhood and adolescent obesity double the risk of MS, but this association may reflect unmeasured confounders rather than causal effects of obesity. We used separate-sample Mendelian randomization to estimate the causal effect of body mass index (BMI) on susceptibility to MS. Using data from non-Hispanic white members of the Kaiser Permanente Medical Care Plan of Northern California (KPNC) (2006-2014; 1,104 cases of MS and 10,536 controls) and a replication data set from Sweden (the Epidemiological Investigation of MS (EIMS) and the Genes and Environment in MS (GEMS) studies, 2005-2013; 5,133 MS cases and 4,718 controls), we constructed a weighted genetic risk score using 97 variants previously established to predict BMI. Results were adjusted for birth year, sex, education, smoking status, ancestry, and genetic predictors of MS. Estimates in KPNC and Swedish data sets suggested that higher genetically induced BMI predicted greater susceptibility to MS (odds ratio = 1.13, 95% confidence interval: 1.04, 1.22 for the KPNC sample; odds ratio = 1.09, 95% confidence interval: 1.03, 1.15 for the Swedish sample). Although the mechanism remains unclear, to our knowledge, these findings support a causal effect of increased BMI on susceptibility to MS for the first time, and they suggest a role for inflammatory pathways that characterize both obesity and the MS disease process.National Institute of Neurological Disorders and Stroke National Institute of Allergy and Infectious Diseases Robert Wood Johnson Foundation Wayne and Gladys Valley Foundation Ellison Medical Foundation AFA Foundation Knut and Alice Wallenberg Foundation Swedish Brain Foundation Margareta af Ugglas Foundation European Union Seventh Framework Programme NEURINOX Swedish Medical Research Council Swedish Research Council for Health, Working Life, and Welfare Biogen Inc Merck Serono Teva Neuroscience Sanofi Novartis Bayer Schering Pharma Swedish Research Council Swedish Childhood Diabetes Foundation Neurologiskt Handikappades Riksforbund Foundation Genzyme Merck Bioge

    Early Alpine occupation backdates westward human migration in Late Glacial Europe

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    Before the end of the Last Glacial Maximum (LGM, ∼16.5 ka ago) set in motion major shifts in human culture and population structure, a consistent change in lithic technology, material culture, settlement pattern, and adaptive strategies is recorded in Southern Europe at ∼18–17 ka ago. In this time frame, the landscape of Northeastern Italy changed considerably, and the retreat of glaciers allowed hunter-gatherers to gradually recolonize the Alps. Change within this renewed cultural frame (i.e., during the Late Epigravettian phase) is currently associated with migrations favored by warmer climate linked to the Bølling-Allerød onset (14.7 ka ago), which replaced earlier genetic lineages with ancestry found in an individual who lived ∼14 ka ago at Riparo Villabruna, Italy, and shared among different contexts (Villabruna Cluster). Nevertheless, these dynamics and their chronology are still far from being disentangled due to fragmentary evidence for long-distance interactions across Europe. Here, we generate new genomic data from a human mandible uncovered at Riparo Tagliente (Veneto, Italy), which we directly dated to 16,980–16,510 cal BP (2σ). This individual, affected by focal osseous dysplasia, is genetically affine to the Villabruna Cluster. Our results therefore backdate by at least 3 ka the diffusion in Southern Europe of a genetic component linked to Balkan/Anatolian refugia, previously believed to have spread during the later Bølling/Allerød event. In light of the new genetic evidence, this population replacement chronologically coincides with the very emergence of major cultural transitions in Southern and Western Europe.The research was supported by the European Union through the European Research Council under the European Union’s Horizon 2020 Research and Innovation Programme (grant agreement no. 724046 – Success awarded to S.B., http://www.erc-success.eu; grant agreement no. 803147 Resolution awarded to S.T., https://site.unibo.it/resolution-erc/en) as well as through the European Regional Development Fund (project no. 2014–2020.4.01.16–0030 to C.L.S. and T.S.) and projects no. 2014-2020.4.01.16-0024 and MOBTT53 (L.P.), by the Estonian Research Council personal research grant (PRG243; C.L.S.), and by UniPd PRID 2019 (L.P.).Peer reviewe
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