1,059 research outputs found

    New evidence on the management of Lewy body dementia

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    This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this recordNote that the article title of the accepted author manuscript is different to that of the final published version.Dementia with Lewy bodies and Parkinson’s disease dementia, jointly known as Lewy body dementia (LBD), are common neurodegenerative conditions. Patients with LBD present with a wide range of cognitive, neuropsychiatric, sleep, motor, and autonomic symptoms. The expression of these varies between individual patients, and over time. Treatments may benefit one symptom, but at the expense of worsening another, making management difficult. Often symptoms are managed in isolation and by different specialists, which undermines high quality care. Clinical trials and meta-analyses now provide an improved evidence base for the treatment of cognitive, neuropsychiatric and motor symptoms in LBD, in addition to which expert consensus opinion supports the application of treatments from related conditions such as Parkinson’s disease (PD) for the management of, for example, autonomic symptoms. There remain however clear evidence gaps and there is a high need for future clinical trials focused on specific symptoms in LBD.National Institute for Health Research (NIHR

    A report from the NIHR UK working group on remote trial delivery for the COVID-19 pandemic and beyond

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    Abstract Background Prior to the COVID-19 pandemic, the majority of clinical trial activity took place face to face within clinical or research units. The COVID-19 pandemic resulted in a significant shift towards trial delivery without in-person face-to-face contact or “Remote Trial Delivery”. The National Institute of Health Research (NIHR) assembled a Remote Trial Delivery Working Group to consider challenges and enablers to this major change in clinical trial delivery and to provide a toolkit for researchers to support the transition to remote delivery. Methods The NIHR Remote Trial Delivery Working Group evaluated five key domains of the trial delivery pathway: participant factors, recruitment, intervention delivery, outcome measurement and quality assurance. Independent surveys were disseminated to research professionals, and patients and carers, to ascertain benefits, challenges, pitfalls, enablers and examples of good practice in Remote Trial Delivery. A toolkit was constructed to support researchers, funders and governance structures in moving towards Remote Trial Delivery. The toolkit comprises a website encompassing the key principles of Remote Trial Delivery, and a repository of best practice examples and questions to guide research teams. Results The patient and carer survey received 47 respondents, 34 of whom were patients and 13 of whom were carers. The professional survey had 115 examples of remote trial delivery practice entered from across England. Key potential benefits included broader reach and inclusivity, the ability for standardisation and centralisation, and increased efficiency and patient/carer convenience. Challenges included the potential exclusion of participants lacking connectivity or digital skills, the lack of digitally skilled workforce and appropriate infrastructure, and validation requirements. Five key principles of Remote Trial Delivery were proposed: national research standards, inclusivity, validity, cost-effectiveness and evaluation of new methodologies. Conclusions The rapid changes towards Remote Trial Delivery catalysed by the COVID-19 pandemic could lead to sustained change in clinical trial delivery. The NIHR Remote Trial Delivery Working Group provide a toolkit for researchers recommending five key principles of Remote Trial Delivery and providing examples of enablers. </jats:sec

    Centre selection for clinical trials and the generalisability of results: a mixed methods study.

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    BACKGROUND: The rationale for centre selection in randomised controlled trials (RCTs) is often unclear but may have important implications for the generalisability of trial results. The aims of this study were to evaluate the factors which currently influence centre selection in RCTs and consider how generalisability considerations inform current and optimal practice. METHODS AND FINDINGS: Mixed methods approach consisting of a systematic review and meta-summary of centre selection criteria reported in RCT protocols funded by the UK National Institute of Health Research (NIHR) initiated between January 2005-January 2012; and an online survey on the topic of current and optimal centre selection, distributed to professionals in the 48 UK Clinical Trials Units and 10 NIHR Research Design Services. The survey design was informed by the systematic review and by two focus groups conducted with trialists at the Birmingham Centre for Clinical Trials. 129 trial protocols were included in the systematic review, with a total target sample size in excess of 317,000 participants. The meta-summary identified 53 unique centre selection criteria. 78 protocols (60%) provided at least one criterion for centre selection, but only 31 (24%) protocols explicitly acknowledged generalisability. This is consistent with the survey findings (n = 70), where less than a third of participants reported generalisability as a key driver of centre selection in current practice. This contrasts with trialists' views on optimal practice, where generalisability in terms of clinical practice, population characteristics and economic results were prime considerations for 60% (n = 42), 57% (n = 40) and 46% (n = 32) of respondents, respectively. CONCLUSIONS: Centres are rarely enrolled in RCTs with an explicit view to external validity, although trialists acknowledge that incorporating generalisability in centre selection should ideally be more prominent. There is a need to operationalize 'generalisability' and incorporate it at the design stage of RCTs so that results are readily transferable to 'real world' practice

    Frontal white matter hyperintensities, clasmatodendrosis and gliovascular abnormalities in ageing and post-stroke dementia

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    White matter hyperintensities as seen on brain T2-weighted magnetic resonance imaging are associated with varying degrees of cognitive dysfunction in stroke, cerebral small vessel disease and dementia. The pathophysiological mechanisms within the white matter accounting for cognitive dysfunction remain unclear. With the hypothesis that gliovascular interactions are impaired in subjects with high burdens of white matter hyperintensities, we performed clinicopathological studies in post-stroke survivors, who had exhibited greater frontal white matter hyperintensities volumes that predicted shorter time to dementia onset. Histopathological methods were used to identify substrates in the white matter that would distinguish post-stroke demented from post-stroke non-demented subjects. We focused on the reactive cell marker glial fibrillary acidic protein (GFAP) to study the incidence and location of clasmatodendrosis, a morphological attribute of irreversibly injured astrocytes. In contrast to normal appearing GFAP + astrocytes, clasmatodendrocytes were swollen and had vacuolated cell bodies. Other markers such as aldehydedehydrogenase 1 family, member L1 (ALDH1L1) showed cytoplasmic disintegration of the astrocytes. Total GFAP + cells in both the frontal and temporal white matter were not greater in post-stroke demented versus post-stroke non-demented subjects. However, the percentage of clasmatodendrocytes was increased by 42-fold in subjects with post-stroke demented compared to post-stroke non-demented subjects (P = 0.026) and by 11-fold in older controls versus young controls (P50.023) in the frontal white matter. High ratios of clasmotodendrocytes to total astrocytes in the frontal white matter were consistent with lower Mini-Mental State Examination and the revised Cambridge Cognition Examination scores in post-stroke demented subjects. Double immunofluorescent staining showed aberrant co-localization of aquaporin 4 (AQP4) in retracted GFAP + astrocytes with disrupted end-feet juxtaposed to microvessels. To explore whether this was associated with the disrupted gliovascular interactions or blood–brain barrier damage, we assessed the co-localization of GFAP and AQP4 immunoreactivities in post-mortem brains from adult baboons with cerebral hypoperfusive injury, induced by occlusion of three major vessels supplying blood to the brain. Analysis of the frontal white matter in perfused brains from the animals surviving 1–28 days after occlusion revealed that the highest intensity of fibrinogen immunoreactivity was at 14 days. At this survival time point, we also noted strikingly similar redistribution of AQP4 and GFAP + astrocytes transformed into clasmatodendrocytes. Our findings suggest novel associations between irreversible astrocyte injury and disruption of gliovascular interactions at the blood–brain barrier in the frontal white matter and cognitive impairment in elderly post-stroke survivors. We propose that clasmatodendrosis is another pathological substrate, linked to white matter hyperintensities and frontal white matter changes, which may contribute to post-stroke or small vessel disease dementia

    Cerebral glucose metabolism and cognition in newly diagnosed Parkinson’s disease: ICICLE-PD study

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    This is the final version of the article. It first appeared from BioMed Central via http://dx.doi.org/10.1136/jnnp-2016-31391

    Low adherent cancer cell subpopulations are enriched in tumorigenic and metastatic epithelial-to-mesenchymal transition-induced cancer stem-like cells

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    Cancer stem cells are responsible for tumor progression, metastasis, therapy resistance and cancer recurrence, doing their identification and isolation of special relevance. Here we show that low adherent breast and colon cancer cells subpopulations have stem-like properties. Our results demonstrate that trypsin-sensitive (TS) breast and colon cancer cells subpopulations show increased ALDH activity, higher ability to exclude Hoechst 33342, enlarged proportion of cells with a cancer stem-like cell phenotype and are enriched in sphere- and colony-forming cells in vitro. Further studies in MDA-MB-231 breast cancer cells reveal that TS subpopulation expresses higher levels of SLUG, SNAIL, VIMENTIN and N-CADHERIN while show a lack of expression of E-CADHERIN and CLAUDIN, being this profile characteristic of the epithelial-to-mesenchymal transition (EMT). The TS subpopulation shows CXCL10, BMI-1 and OCT4 upregulation, differing also in the expression of several miRNAs involved in EMT and/or cell self-renewal such as miR-34a-5p, miR-34c-5p, miR-21-5p, miR-93-5p and miR-100-5p. Furthermore, in vivo studies in immunocompromised mice demonstrate that MDA-MB-231 TS cells form more and bigger xenograft tumors with shorter latency and have higher metastatic potential. In conclusion, this work presents a new, non-aggressive, easy, inexpensive and reproducible methodology to isolate prospectively cancer stem-like cells for subsequent biological and preclinical studies.Ministry of Economy and Competitiveness, Instituto de Salud Carlos III (FEDER funds) PI10/02295 PI10/02149Fundacion Progreso y Salud, Consejeria de Salud, Junta de Andalucia (Ministry of Health, Government of Andalucia) PI-0533-2014Consejeria Economia, Innovacion, Ciencia y Empleo, Junta de Andalucia (Ministry of Economy, Innovation, Science and Employment, Government of Andalucia) CTS-656

    The Escherichia coli transcriptome mostly consists of independently regulated modules

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    Underlying cellular responses is a transcriptional regulatory network (TRN) that modulates gene expression. A useful description of the TRN would decompose the transcriptome into targeted effects of individual transcriptional regulators. Here, we apply unsupervised machine learning to a diverse compendium of over 250 high-quality Escherichia coli RNA-seq datasets to identify 92 statistically independent signals that modulate the expression of specific gene sets. We show that 61 of these transcriptomic signals represent the effects of currently characterized transcriptional regulators. Condition-specific activation of signals is validated by exposure of E. coli to new environmental conditions. The resulting decomposition of the transcriptome provides: a mechanistic, systems-level, network-based explanation of responses to environmental and genetic perturbations; a guide to gene and regulator function discovery; and a basis for characterizing transcriptomic differences in multiple strains. Taken together, our results show that signal summation describes the composition of a model prokaryotic transcriptome

    Clinical diagnosis of Lewy body dementia

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    This is the final version. Available on open access from Cambridge University Press via the DOI in this recordBackground Lewy body dementia consisting of both dementia with Lewy bodies (DLB) and Parkinson’s disease (PD) dementia (PDD) is considerably under-recognised clinically compared to its frequency in autopsy series. Aims This study investigated the clinical diagnostic pathways of patients with Lewy body dementia to assess if difficulties in diagnosis maybe contributing to these differences. Methods We reviewed the medical notes of 74 DLB and 72 non-DLB dementia cases matched for age, gender and cognitive performance, together with 38 PDD cases and 35 PD cases, matched for age and gender, from two geographically distinct UK regions. Results DLB cases took longer to reach a final diagnosis (1.2v0.6 years, p=0.003), underwent more scans (1.7v1.2, p=0.017) and had more alternative prior diagnoses (0.8v0.4, p=0.002), than non-DLB cases. Cases diagnosed in one region had significantly more core features (2.1v1.5, p=0.007) than in the other and were less likely to have dopamine transporter imaging (p<0.001). For PDD cases, more than 1.4 years prior to receiving a dementia diagnosis, 46% had documented impaired activities of daily living due to cognitive impairment, 57% had cognitive impairment in multiple domains, with 38% having both, and 39% already receiving anti-dementia drugs. 3 Conclusions Our results show the pathway to diagnosis of DLB is longer and more complex than nonDLB dementia. There were also marked differences between regions in the thresholds clinicians adopt for diagnosing DLB and also in the use of dopamine transporter imaging. Whilst for PDD, a diagnosis of dementia was delayed well beyond symptom onset and even treatment.National Institute for Health Research (NIHR
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