699 research outputs found

    Could an Impairment in Local Translation of mRNAs in Glia be Contributing to Pathogenesis in ALS?

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    One of the key pathways implicated in amyotrophic lateral sclerosis (ALS) pathogenesis is abnormal RNA processing. Studies to date have focussed on defects in RNA stability, splicing, and translation, but this review article will focus on the largely overlooked RNA processing mechanism of RNA trafficking, with particular emphasis on the importance of glia. In the central nervous system (CNS), oligodendrocytes can extend processes to myelinate and metabolically support up to 50 axons and astrocytes can extend processes to cover up to 100,000 synapses, all with differing local functional requirements. Furthermore, many of the proteins required in these processes are large, aggregation-prone proteins which would be difficult to transport in their fully translated, terminally-folded state. This, therefore, highlights a critical requirement in these cells for local control of protein translation, which is achieved through specific trafficking of mRNAs to each process and local translation therein. Given that a large number of RNA-binding proteins have been implicated in ALS, and RNA-binding proteins are essential for trafficking mRNAs from the nucleus to glial processes for local translation, RNA misprocessing in glial cells is a likely source of cellular dysfunction in ALS. To date, neurons have been the focus of ALS research, but an intrinsic deficit in glia, namely astrocytes and oligodendrocytes, could have an additive effect on declining neuronal function in ALS. This review article aims to highlight the key evidence that supports the contention that RNA trafficking deficits in astrocytes and oligodendrocytes may contribute to in ALS

    Perisylvian and Hippocampal Anomalies in Individuals With Pathogenic GRIN2A Variants

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    BACKGROUND AND OBJECTIVES: Pathogenic variants in GRIN2A are associated with a spectrum of epilepsy-aphasia syndromes (EASs). Seizures as well as speech and language disorders occur frequently but vary widely in severity, both between individuals and across the life span. The link between this phenotypic spectrum and brain characteristics is unknown. Specifically, altered brain networks at the root of speech and language deficits remain to be identified. Patients with pathogenic variants in GRIN2A offer an opportunity to interrogate the impact of glutamate receptor dysfunction on brain development. METHODS: We characterized brain anomalies in individuals with pathogenic GRIN2A variants and EASs, hypothesizing alterations in perisylvian speech-language regions and the striatum. We compared structural MRI data from 10 individuals (3 children and 7 adults, 3 female) with pathogenic GRIN2A variants with data from age-matched controls (N = 51 and N = 203 in a secondary analysis). We examined cortical thickness and volume in 4 a priori hypothesized speech and language regions (inferior frontal, precentral, supramarginal, and superior temporal) and across the whole brain. Subcortical structures (hippocampus, basal ganglia, thalamus) and the corpus callosum were also compared. RESULTS: Individuals with pathogenic GRIN2A variants showed increased thickness and volume in the posterior part of Broca's area (inferior frontal gyrus, pars opercularis). For thickness, the effects were bilateral but more pronounced in the left (large effect size, Ī·2 = 0.37) than the right (Ī·2 = 0.12) hemisphere. Both volume and thickness were also higher in the bilateral superior temporal region while the supramarginal region showed increased thickness only. Whole-brain analyses confirmed left-sided thickness increases in Broca's area, with additional increases in the occipital and superior frontal cortices bilaterally. Hippocampal volume was reduced in the left hemisphere. There were no age-dependent effects or corpus callosum group differences. DISCUSSION: Anomalies in perisylvian regions, with largest differences in Broca's area, suggest an altered development of classical speech-language networks in GRIN2A-related EAS. Left hippocampal reduction suggests a role for this structure in early speech and language development and is consistent with GRIN2A gene expression in that region. Overall, elucidating the neural correlates of EAS provides insights into the impact of GRIN2A dysfunction, opening avenues for targeted intervention in developmental syndromes with compromised speech-language development

    Voluntary Exercise Reduces Alzheimerā€™s-like Pathology After Inflammation in Mice

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    Current global statistics estimate that 44.4 million people are afflicted with dementia, and that 50%-75% of these patients suffer from Alzheimerā€™s disease (AD; Prince et al. 2013). AD, a progressive disorder categorized by neuronal and behavioral deterioration, is the 6th leading cause of death in America (Alz facts and figure 2012). One hallmark pathology of AD is the presence of amyloid-beta (AĪ²) in the brain, which can limit cell-to-cell communication, leading to cognitive deficits, and neuronal cell death. Although the exact origins of this disease still remain unknown, one possible catalyst of AD pathology is inflammation. Our lab has previously shown that 7 consecutive peripheral injections of a bacterial mimetic led to systemic inflammation, increased levels of Ab in the brain, and cognitive dysfunction (Kahn et al., 2012; Weintraub et al., 2013). Currently there are very few effective treatments that diminish AD symptomology. One documented way to decrease inflammation without the use of pharmaceuticals is through regular physical exercise (Cho et al., 2003; Cotman & Berchtold, 2002; Cotman et al., 2007). The present study tested the hypothesis that voluntary exercise would decrease the level of brain Ab following inflammation. Interestingly, we found that two weeks of voluntary wheel running after inflammation led to a reduction of Ab when compared to sedentary recovery. These results indicate that exercise may be an effective modality to reduce AD-like pathology, and that these effects appear to be facilitated by higher versus lower levels of exercise, as measured by total distance run

    Genome-wide changes in genetic diversity in a population of Myotis lucifugus affected by white-nose syndrome

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    Novel pathogens can cause massive declines in populations, and even extirpation of hosts. But disease can also act as a selective pressure on survivors, driving the evolution of resistance or tolerance. Bat white-nose syndrome (WNS) is a rapidly spreading wildlife disease in North America. The fungus causing the disease invades skin tissues of hibernating bats, resulting in disruption of hibernation behavior, premature energy depletion, and subsequent death. We used whole-genome sequencing to investigate changes in allele frequencies within a population of Myotis lucifugus in eastern North America to search for genetic resistance to WNS. Our results show low F-ST values within the population across time, i.e., prior to WNS (Pre-WNS) compared to the population that has survived WNS (Post-WNS). However, when dividing the population with a geographical cut-off between the states of Pennsylvania and New York, a sharp increase in values on scaffold GL429776 is evident in the Post-WNS samples. Genes present in the diverged area are associated with thermoregulation and promotion of brown fat production. Thus, although WNS may not have subjected the entire M. lucifugus population to selective pressure, it may have selected for specific alleles in Pennsylvania through decreased gene flow within the population. However, the persistence of remnant sub-populations in the aftermath of WNS is likely due to multiple factors in bat life history.Peer reviewe

    Physical activity monitoring: Addressing the difficulties of accurately detecting slow walking speeds

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    OBJECTIVE: To test the accuracy of a multi-sensor activity monitor (SWM) in detecting slow walking speeds in patients with chronic obstructive pulmonary disease (COPD). BACKGROUND: Concerns have been expressed regarding the use of pedometers in patient populations. Although activity monitors are more sophisticated devices, their accuracy at detecting slow walking speeds common in patients with COPD has yet to be proven. METHODS: A prospective observational study design was employed. An incremental shuttle walk test (ISWT) was completed by 57 patients with COPD wearing an SWM. The ISWT was repeated by 20 patients wearing the same SWM. RESULTS: Differences were identified between metabolic equivalents (METS) and between step-count across five levels of the ISWT (p < 0.001). Good within monitor reproducibility between two ISWT was identified for total energy expenditure and step-count (p < 0.001). CONCLUSIONS: The SWM is able to detect slow (standardized) speeds of walking and is an acceptable method for measuring physical activity in individuals disabled by COPD

    The subjective world of home care workers in dementia: an ā€œorder of worthā€ analysis

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    The perspective of domiciliary workers is needed to recruit a high-quality workforce and meet growing demand. An English ethnographic study yielded extensive insights. To structure analysis of the study data, we apply a method developed by political theorists Boltanski and ThĆ©venot that identifies key variables in different values systems. This ā€œorders of worthā€ framework is used to map out the distinctive features of the subjective world of home carers. The results can be drawn on to formulate recruitment and retention policies, to design reward strategies or to ensure that training and education opportunities engage effectively with the workforce

    Interventions to increase physical activity and reduce sedentary behaviour in severe mental ill health: How effective are they?ā€™- A systematic review.

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    Background People with severe mental ill health experience a mortality gap of 15ā€“20 years and one of the main reasons for this is due to preventable physical health conditions. Physical activity can reduce the risk of developing physical health conditions such as diabetes and cardiovascular disease yet people with severe mental ill health are less physically active and more sedentary than the general population. Methods A systematic review was conducted to investigate the effectiveness of interventions aimed at increasing physical activity and reducing sedentary behaviour in people with severe mental ill health. The protocol was published with PROSPERO (CRD42021277579). Randomised controlled trials conducted in any country in any setting and published in English with an aim of increasing physical activity or reducing sedentary behaviour were included. Results Eleven unique studies were identified for inclusion. Due to the variability between interventions, outcome measures, and time points, it was not possible to conduct a meta-analysis. Effect estimates suggested that three of the interventions were effective at increasing physical activity. However, the certainty of the evidence was rated as low using the GRADE approach. Conclusions The evidence on interventions to increase activity shows promise but is insufficiently robust for an intervention to be recommended in clinical guidelines. More high-quality and statistically powered trials are needed to guide best practice and policy

    Promoting Junior School Studentsā€™ Anti-bullying Beliefs with the CATZ Cross-age Teaching Zone Intervention

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    In tackling the widespread problem of bullying victimisation, researchers have acknowledged the value of focusing on changing bullying-related beliefs and using peer-based interventions. In three studies (Nā€‰=ā€‰419, 237 intervention and 182 controls), we tested the effectiveness of the CATZ cross-age teaching programme by inviting small groups of 11-year-olds to incorporate information supporting positive beliefs (concerning non-physical forms of bullying, the value of disclosing being bullied to adults, and helping victims) into a lesson they devised for themselves and to deliver that to small groups of 9-year-olds. Specifically, we examined if the intervention would promote that (i) non-physical forms of bullying are unacceptable (study 1), (ii) disclosing bullying to adults and getting the right kind of help have value and importance (study 2), and (iii) victims can be assisted in safe ways (study 3). Self-reports of nine specific aspects of these beliefs were collected from CATZ tutors and age-matched controls prior to and following the intervention, and at five-week follow-up in one study, using both open and closed questions. Results indicated significant positive effects of CATZ on all nine outcome variables, with mostly medium and high effect sizes. These findings support the use of CATZ to foster positive anti-bullying beliefs, and issues related to its wider uptake are discussed.N/

    Efficiency and safety of varying the frequency of whole blood donation (INTERVAL): a randomised trial of 45 000 donors

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    Background: Limits on the frequency of whole blood donation exist primarily to safeguard donor health. However, there is substantial variation across blood services in the maximum frequency of donations allowed. We compared standard practice in the UK with shorter inter-donation intervals used in other countries. Methods: In this parallel group, pragmatic, randomised trial, we recruited whole blood donors aged 18 years or older from 25 centres across England, UK. By use of a computer-based algorithm, men were randomly assigned (1:1:1) to 12-week (standard) versus 10-week versus 8-week inter-donation intervals, and women were randomly assigned (1:1:1) to 16-week (standard) versus 14-week versus 12-week intervals. Participants were not masked to their allocated intervention group. The primary outcome was the number of donations over 2 years. Secondary outcomes related to safety were quality of life, symptoms potentially related to donation, physical activity, cognitive function, haemoglobin and ferritin concentrations, and deferrals because of low haemoglobin. This trial is registered with ISRCTN, number ISRCTN24760606, and is ongoing but no longer recruiting participants. Findings: 45ā€ˆ263 whole blood donors (22ā€ˆ466 men, 22ā€ˆ797 women) were recruited between June 11, 2012, and June 15, 2014. Data were analysed for 45ā€ˆ042 (99Ā·5%) participants. Men were randomly assigned to the 12-week (n=7452) versus 10-week (n=7449) versus 8-week (n=7456) groups; and women to the 16-week (n=7550) versus 14-week (n=7567) versus 12-week (n=7568) groups. In men, compared with the 12-week group, the mean amount of blood collected per donor over 2 years increased by 1Ā·69 units (95% CI 1Ā·59ā€“1Ā·80; approximately 795 mL) in the 8-week group and by 0Ā·79 units (0Ā·69ā€“0Ā·88; approximately 370 mL) in the 10-week group (p&lt;0Ā·0001 for both). In women, compared with the 16-week group, it increased by 0Ā·84 units (95% CI 0Ā·76ā€“0Ā·91; approximately 395 mL) in the 12-week group and by 0Ā·46 units (0Ā·39ā€“0Ā·53; approximately 215 mL) in the 14-week group (p&lt;0Ā·0001 for both). No significant differences were observed in quality of life, physical activity, or cognitive function across randomised groups. However, more frequent donation resulted in more donation-related symptoms (eg, tiredness, breathlessness, feeling faint, dizziness, and restless legs, especially among men [for all listed symptoms]), lower mean haemoglobin and ferritin concentrations, and more deferrals for low haemoglobin (p&lt;0Ā·0001 for each) than those observed in the standard frequency groups. Interpretation: Over 2 years, more frequent donation than is standard practice in the UK collected substantially more blood without having a major effect on donors' quality of life, physical activity, or cognitive function, but resulted in more donation-related symptoms, deferrals, and iron deficiency. Funding: NHS Blood and Transplant, National Institute for Health Research, UK Medical Research Council, and British Heart Foundation
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