1,411 research outputs found

    The occurrence of fossil plants at Warrentinna, Tasmania

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    An outcrop in which plant-remains of early Palaeozoic type occur is situated in the railway-cutting 8 chains south of Warrentinna Railway-station, in North-Eastern Tasmania. The results of this work at Warrentinna,though unsatisfactory on account of the imperfect and fragmentary nature of the specimens obtained, are recorded here in the hope that interest may be stimulated in Tasmania which will lead to the discovery of new fossiliferous beds in the same rock series

    Hallmarks of neurodegenerative diseases

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    Decades of research have identified genetic factors and biochemical pathways involved in neurodegenerative diseases (NDDs). We present evidence for the following eight hallmarks of NDD: pathological protein aggregation, synaptic and neuronal network dysfunction, aberrant proteostasis, cytoskeletal abnormalities, altered energy homeostasis, DNA and RNA defects, inflammation, and neuronal cell death. We describe the hallmarks, their biomarkers, and their interactions as a framework to study NDDs using a holistic approach. The framework can serve as a basis for defining pathogenic mechanisms, categorizing different NDDs based on their primary hallmarks, stratifying patients within a specific NDD, and designing multi-targeted, personalized therapies to effectively halt NDDs

    Whole lifespan microscopic observation of budding yeast aging through a microfluidic dissection platform

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    Important insights into aging have been generated with the genetically tractable and short-lived budding yeast. However, it is still impossible today to continuously track cells by high-resolution microscopic imaging (e.g., fluorescent imaging) throughout their entire lifespan. Instead, the field still needs to rely on a 50-y-old laborious and time-consuming method to assess the lifespan of yeast cells and to isolate differentially aged cells for microscopic snapshots via manual dissection of daughter cells from the larger mother cell. Here, we are unique in achieving continuous and high-resolution microscopic imaging of the entire replicative lifespan of single yeast cells. Our microfluidic dissection platform features an optically prealigned single focal plane and an integrated array of soft elastomer-based micropads, used together to allow for trapping of mother cells, removal of daughter cells, monitoring gradual changes in aging, and unprecedented microscopic imaging of the whole aging process. Using the platform, we found remarkable age-associated changes in phenotypes (e.g., that cells can show strikingly differential cell and vacuole morphologies at the moment of their deaths), indicating substantial heterogeneity in cell aging and death. We envision the microfluidic dissection platform to become a major tool in aging research.

    A behavioural change package to prevent hand dermatitis in nurses working in the national health service (the SCIN trial): study protocol for a cluster randomised controlled trial

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    BACKGROUND: Hand dermatitis can be a serious health problem in healthcare workers. While a range of skin care strategies and policy directives have been developed in recent years to minimise the risk, their effectiveness and cost-effectiveness remain unclear. Evidence now suggests that psychological theory can facilitate behaviour change with respect to improved hand care practices. Therefore, we will test the hypothesis that a behavioural change intervention to improve hand care, based on the Theory of Planned Behaviour and implementation intentions, coupled with provision of hand moisturisers, can produce a clinically useful reduction in the occurrence of hand dermatitis, when compared to standard care, among nurses working in the UK National Health Service (NHS) who are particularly at risk. Secondary aims will be to assess impacts on participants’ beliefs and behaviour regarding hand care. In addition, we will assess the cost-effectiveness of the intervention in comparison with normal care. METHODS/DESIGN: We will conduct a cluster randomised controlled trial at 35 NHS hospital trusts/health boards/universities, focussing on student nurses with a previous history of atopic disease or hand eczema and on nurses in intensive care units. Nurses at ‘intervention-light’ sites will be managed according to what would currently be regarded as best practice, with provision of an advice leaflet about optimal hand care to prevent hand dermatitis and encouragement to contact their occupational health (OH) department early if hand dermatitis occurs. Nurses at ‘intervention-plus’ sites will additionally receive a behavioural change programme (BCP) with on-going active reinforcement of its messages, and enhanced provision of moisturising cream. The impact of the interventions will be compared using information collected by questionnaires and through standardised photographs of the hands and wrists, collected at baseline and after 12 months follow-up. In addition, we will assemble relevant economic data for an analysis of costs and benefits, and collect information from various sources to evaluate processes. Statistical analysis will be by multi-level regression modelling to allow for clustering by site, and will compare the prevalence of outcome measures at follow-up after adjustment for values at baseline. The principal outcome measure will be the prevalence of visible hand dermatitis as assessed by the study dermatologists. In addition, several secondary outcome measures will be assessed. DISCUSSION: This trial will assess the clinical and cost effectiveness of an intervention to prevent hand dermatitis in nurses in the United Kigdom. TRIAL REGISTRATION: ISRCTN53303171: date of registration, 21 June 2013

    A behaviour change package to prevent hand dermatitis in nurses working in health care: the SCIN cluster RCT

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    BACKGROUND: Although strategies have been developed to minimise the risk of occupational hand dermatitis in nurses, their clinical effectiveness and cost-effectiveness remain unclear. OBJECTIVES: The Skin Care Intervention in Nurses trial tested the hypothesis that a behaviour change package intervention, coupled with provision of hand moisturisers, could reduce the point prevalence of hand dermatitis when compared with standard care among nurses working in the NHS. The secondary aim was to assess the impact of the intervention on participants' beliefs and behaviour regarding hand care, and the cost-effectiveness of the intervention in comparison with normal care. DESIGN: Cluster randomised controlled trial. SETTING: Thirty-five NHS hospital trusts/health boards/universities. PARTICIPANTS: First-year student nurses with a history of atopic tendency, and full-time intensive care unit nurses. INTERVENTION: Sites were randomly allocated to be 'intervention plus' or 'intervention light'. Participants at 'intervention plus' sites received access to a bespoke online behaviour change package intervention, coupled with personal supplies of moisturising cream (student nurses) and optimal availability of moisturising cream (intensive care unit nurses). Nurses at 'intervention light' sites received usual care, including a dermatitis prevention leaflet. MAIN OUTCOME MEASURE: The difference between intervention plus and intervention light sites in the change of point prevalence of visible hand dermatitis was measured from images taken at baseline and at follow-up. RANDOMISATION: Fourteen sites were randomised to the intervention plus arm, and 21 sites were randomised to the intervention light arm. BLINDING: The participants, trial statistician, methodologist and the dermatologists interpreting the hand photographs were blinded to intervention assignment. NUMBERS ANALYSED: An intention-to-treat analysis was conducted on data from 845 student nurses and 1111 intensive care unit nurses. RESULTS: The intention-to-treat analysis showed no evidence that the risk of developing dermatitis was greater in the intervention light group than in the intervention plus group (student nurses: odds ratio 1.25, 95% confidence interval 0.59 to 2.69; intensive care unit nurses: odds ratio 1.41, 95% confidence interval 0.81 to 2.44). Both groups had high levels of baseline beliefs about the benefits of using hand moisturisers before, during and after work. The frequency of use of hand moisturisers before, during and after shifts was significantly higher in the intensive care unit nurses in the intervention plus arm at follow-up than in the comparator group nurses. For student nurses, the intervention plus group mean costs were £2 lower than those for the comparator and 0.00002 more quality-adjusted life-years were gained. For intensive care unit nurses, costs were £4 higher and 0.0016 fewer quality-adjusted life-years were gained. HARMS: No adverse events were reported. LIMITATIONS: Only 44.5% of participants in the intervention plus arm accessed the behaviour change package. CONCLUSION: The intervention did not result in a statistically significant decrease in the prevalence of hand dermatitis in the intervention plus group. FUTURE WORK: Participants had a high level of baseline beliefs about the importance of using hand moisturisers before, during and after work. Future research should focus on how workplace culture can be changed in order for that knowledge to be actioned. TRIAL REGISTRATION: Current Controlled Trials ISRCTN53303171. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 23, No. 58. See the NIHR Journals Library website for further project information

    Differential cargo mobilisation within Weibel-Palade bodies after transient fusion with the plasma membrane.

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    Inflammatory chemokines can be selectively released from Weibel-Palade bodies (WPBs) during kiss-and-run exocytosis. Such selectivity may arise from molecular size filtering by the fusion pore, however differential intra-WPB cargo re-mobilisation following fusion-induced structural changes within the WPB may also contribute to this process. To determine whether WPB cargo molecules are differentially re-mobilised, we applied FRAP to residual post-fusion WPB structures formed after transient exocytosis in which some or all of the fluorescent cargo was retained. Transient fusion resulted in WPB collapse from a rod to a spheroid shape accompanied by substantial swelling (>2 times by surface area) and membrane mixing between the WPB and plasma membranes. Post-fusion WPBs supported cumulative WPB exocytosis. To quantify diffusion inside rounded organelles we developed a method of FRAP analysis based on image moments. FRAP analysis showed that von Willebrand factor-EGFP (VWF-EGFP) and the VWF-propolypeptide-EGFP (Pro-EGFP) were immobile in post-fusion WPBs. Because Eotaxin-3-EGFP and ssEGFP (small soluble cargo proteins) were largely depleted from post-fusion WPBs, we studied these molecules in cells preincubated in the weak base NH4Cl which caused WPB alkalinisation and rounding similar to that produced by plasma membrane fusion. In these cells we found a dramatic increase in mobilities of Eotaxin-3-EGFP and ssEGFP that exceeded the resolution of our method (∼ 2.4 µm2/s mean). In contrast, the membrane mobilities of EGFP-CD63 and EGFP-Rab27A in post-fusion WPBs were unchanged, while P-selectin-EGFP acquired mobility. Our data suggest that selective re-mobilisation of chemokines during transient fusion contributes to selective chemokine secretion during transient WPB exocytosis. Selective secretion provides a mechanism to regulate intravascular inflammatory processes with reduced risk of thrombosis

    Effects of different antibiotic classes on airway bacteria in stable COPD using culture and molecular techniques: a randomised controlled trial

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    Long-term antibiotic therapy is used to prevent exacerbations of COPD but there is uncertainty over whether this reduces airway bacteria. The optimum antibiotic choice remains unknown. We conducted an exploratory trial in stable patients with COPD comparing three antibiotic regimens against placebo

    Cerebrospinal fluid CXCL10 is associated with the presence of low level CSF HIV during suppressive antiretroviral therapy

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    Surrogate markers of HIV central nervous system (CNS) persistence are needed because direct HIV measurements from the CNS require specialized protocols and are not always detectable or quantifiable. We analyzed paired plasma and CSF samples from people with HIV (PWH) on suppressive therapy (ART) with a validated HIV single copy RNA assay. Two potential markers of CNS persistence were measured (CXCL10 and sCD30). We then examined associations with CSF HIV RNA positivity in univariable and multivariable analyses. Among 66 individuals, 18.2% had detectable CSF HIV. Individuals who had detectable HIV in CSF had higher CSF CXCL10 concentrations (median 514 pg/ml versus median 317 pg/ml, p = 0.019), but did not have significantly different CSF sCD30 concentrations (median 7.5 ng/ml versus median 7.6 ng/ml, p = 0.78). In the multiple logistic analysis, both higher CSF CXCL10 (p = 0.038) and plasma HIV detectability (p = 0.035) were significantly associated with detectable CSF HIV. Both sCD30 and CXCL10 correlated positively with NfL and NSE, two neuronal markers. This study demonstrates that CSF CXCL10 concentrations reflect low level HIV CNS persistence despite virologic suppression on ART. Given that it is readily detectable and quantifiable, this chemokine may be a promising biomarker to evaluate HIV eradication therapies that target the CNS

    PAK6 Phosphorylates 14-3-3 gamma to Regulate Steady State Phosphorylation of LRRK2

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    Mutations in Leucine-rich repeat kinase 2 (LRRK2) are associated with Parkinson’s disease (PD) and, as such, LRRK2 is considered a promising therapeutic target for age-related neurodegeneration. Although the cellular functions of LRRK2 in health and disease are incompletely understood, robust evidence indicates that PD-associated mutations alter LRRK2 kinase and GTPase activities with consequent deregulation of the downstream signaling pathways. We have previously demonstrated that one LRRK2 binding partner is P21 (RAC1) Activated Kinase 6 (PAK6). Here, we interrogate the PAK6 interactome and find that PAK6 binds a subset of 14-3-3 proteins in a kinase dependent manner. Furthermore, PAK6 efficiently phosphorylates 14-3-3γ at Ser59 and this phosphorylation serves as a switch to dissociate the chaperone from client proteins including LRRK2, a well-established 14-3-3 binding partner. We found that 14-3-3γ phosphorylated by PAK6 is no longer competent to bind LRRK2 at phospho-Ser935, causing LRRK2 dephosphorylation. To address whether these interactions are relevant in a neuronal context, we demonstrate that a constitutively active form of PAK6 rescues the G2019S LRRK2-associated neurite shortening through phosphorylation of 14-3-3γ. Our results identify PAK6 as the kinase for 14-3-3γ and reveal a novel regulatory mechanism of 14-3-3/LRRK2 complex in the brain
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