58 research outputs found

    Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial

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    Background Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy

    Assessment of β-amyloid deposits in human brain: a study of the BrainNet Europe Consortium

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    β-Amyloid (Aβ) related pathology shows a range of lesions which differ both qualitatively and quantitatively. Pathologists, to date, mainly focused on the assessment of both of these aspects but attempts to correlate the findings with clinical phenotypes are not convincing. It has been recently proposed in the same way as ι and α synuclein related lesions, also Aβ related pathology may follow a temporal evolution, i.e. distinct phases, characterized by a step-wise involvement of different brain-regions. Twenty-six independent observers reached an 81% absolute agreement while assessing the phase of Aβ, i.e. phase 1 = deposition of Aβ exclusively in neocortex, phase 2 = additionally in allocortex, phase 3 = additionally in diencephalon, phase 4 = additionally in brainstem, and phase 5 = additionally in cerebellum. These high agreement rates were reached when at least six brain regions were evaluated. Likewise, a high agreement (93%) was reached while assessing the absence/presence of cerebral amyloid angiopathy (CAA) and the type of CAA (74%) while examining the six brain regions. Of note, most of observers failed to detect capillary CAA when it was only mild and focal and thus instead of type 1, type 2 CAA was diagnosed. In conclusion, a reliable assessment of Aβ phase and presence/absence of CAA was achieved by a total of 26 observers who examined a standardized set of blocks taken from only six anatomical regions, applying commercially available reagents and by assessing them as instructed. Thus, one may consider rating of Aβ-phases as a diagnostic tool while analyzing subjects with suspected Alzheimer’s disease (AD). Because most of these blocks are currently routinely sampled by the majority of laboratories, assessment of the Aβ phase in AD is feasible even in large scale retrospective studies

    Effects of antiplatelet therapy after stroke due to intracerebral haemorrhage (RESTART): a randomised, open-label trial

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    Background: Antiplatelet therapy reduces the risk of major vascular events for people with occlusive vascular disease, although it might increase the risk of intracranial haemorrhage. Patients surviving the commonest subtype of intracranial haemorrhage, intracerebral haemorrhage, are at risk of both haemorrhagic and occlusive vascular events, but whether antiplatelet therapy can be used safely is unclear. We aimed to estimate the relative and absolute effects of antiplatelet therapy on recurrent intracerebral haemorrhage and whether this risk might exceed any reduction of occlusive vascular events. Methods: The REstart or STop Antithrombotics Randomised Trial (RESTART) was a prospective, randomised, open-label, blinded endpoint, parallel-group trial at 122 hospitals in the UK. We recruited adults (≥18 years) who were taking antithrombotic (antiplatelet or anticoagulant) therapy for the prevention of occlusive vascular disease when they developed intracerebral haemorrhage, discontinued antithrombotic therapy, and survived for 24 h. Computerised randomisation incorporating minimisation allocated participants (1:1) to start or avoid antiplatelet therapy. We followed participants for the primary outcome (recurrent symptomatic intracerebral haemorrhage) for up to 5 years. We analysed data from all randomised participants using Cox proportional hazards regression, adjusted for minimisation covariates. This trial is registered with ISRCTN (number ISRCTN71907627). Findings: Between May 22, 2013, and May 31, 2018, 537 participants were recruited a median of 76 days (IQR 29–146) after intracerebral haemorrhage onset: 268 were assigned to start and 269 (one withdrew) to avoid antiplatelet therapy. Participants were followed for a median of 2·0 years (IQR [1·0– 3·0]; completeness 99·3%). 12 (4%) of 268 participants allocated to antiplatelet therapy had recurrence of intracerebral haemorrhage compared with 23 (9%) of 268 participants allocated to avoid antiplatelet therapy (adjusted hazard ratio 0·51 [95% CI 0·25–1·03]; p=0·060). 18 (7%) participants allocated to antiplatelet therapy experienced major haemorrhagic events compared with 25 (9%) participants allocated to avoid antiplatelet therapy (0·71 [0·39–1·30]; p=0·27), and 39 [15%] participants allocated to antiplatelet therapy had major occlusive vascular events compared with 38 [14%] allocated to avoid antiplatelet therapy (1·02 [0·65–1·60]; p=0·92). Interpretation: These results exclude all but a very modest increase in the risk of recurrent intracerebral haemorrhage with antiplatelet therapy for patients on antithrombotic therapy for the prevention of occlusive vascular disease when they developed intracerebral haemorrhage. The risk of recurrent intracerebral haemorrhage is probably too small to exceed the established benefits of antiplatelet therapy for secondary prevention

    Effects of antiplatelet therapy after stroke due to intracerebral haemorrhage (RESTART): a randomised, open-label trial

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    Background: Antiplatelet therapy reduces the risk of major vascular events for people with occlusive vascular disease, although it might increase the risk of intracranial haemorrhage. Patients surviving the commonest subtype of intracranial haemorrhage, intracerebral haemorrhage, are at risk of both haemorrhagic and occlusive vascular events, but whether antiplatelet therapy can be used safely is unclear. We aimed to estimate the relative and absolute effects of antiplatelet therapy on recurrent intracerebral haemorrhage and whether this risk might exceed any reduction of occlusive vascular events. Methods: The REstart or STop Antithrombotics Randomised Trial (RESTART) was a prospective, randomised, open-label, blinded endpoint, parallel-group trial at 122 hospitals in the UK. We recruited adults (≥18 years) who were taking antithrombotic (antiplatelet or anticoagulant) therapy for the prevention of occlusive vascular disease when they developed intracerebral haemorrhage, discontinued antithrombotic therapy, and survived for 24 h. Computerised randomisation incorporating minimisation allocated participants (1:1) to start or avoid antiplatelet therapy. We followed participants for the primary outcome (recurrent symptomatic intracerebral haemorrhage) for up to 5 years. We analysed data from all randomised participants using Cox proportional hazards regression, adjusted for minimisation covariates. This trial is registered with ISRCTN (number ISRCTN71907627). Findings: Between May 22, 2013, and May 31, 2018, 537 participants were recruited a median of 76 days (IQR 29–146) after intracerebral haemorrhage onset: 268 were assigned to start and 269 (one withdrew) to avoid antiplatelet therapy. Participants were followed for a median of 2·0 years (IQR [1·0– 3·0]; completeness 99·3%). 12 (4%) of 268 participants allocated to antiplatelet therapy had recurrence of intracerebral haemorrhage compared with 23 (9%) of 268 participants allocated to avoid antiplatelet therapy (adjusted hazard ratio 0·51 [95% CI 0·25–1·03]; p=0·060). 18 (7%) participants allocated to antiplatelet therapy experienced major haemorrhagic events compared with 25 (9%) participants allocated to avoid antiplatelet therapy (0·71 [0·39–1·30]; p=0·27), and 39 [15%] participants allocated to antiplatelet therapy had major occlusive vascular events compared with 38 [14%] allocated to avoid antiplatelet therapy (1·02 [0·65–1·60]; p=0·92). Interpretation: These results exclude all but a very modest increase in the risk of recurrent intracerebral haemorrhage with antiplatelet therapy for patients on antithrombotic therapy for the prevention of occlusive vascular disease when they developed intracerebral haemorrhage. The risk of recurrent intracerebral haemorrhage is probably too small to exceed the established benefits of antiplatelet therapy for secondary prevention

    The human cytomegalovirus ul11 protein interacts with the receptor tyrosine phosphatase cd45, resulting in functional paralysis of t cells

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    Human cytomegalovirus (CMV) exerts diverse and complex effects on the immune system, not all of which have been attributed to viral genes. Acute CMV infection results in transient restrictions in T cell proliferative ability, which can impair the control of the virus and increase the risk of secondary infections in patients with weakened or immature immune systems. In a search for new immunomodulatory proteins, we investigated the UL11 protein, a member of the CMV RL11 family. This protein family is defined by the RL11 domain, which has homology to immunoglobulin domains and adenoviral immunomodulatory proteins. We show that pUL11 is expressed on the cell surface and induces intercellular interactions with leukocytes. This was demonstrated to be due to the interaction of pUL11 with the receptor tyrosine phosphatase CD45, identified by mass spectrometry analysis of pUL11-associated proteins. CD45 expression is sufficient to mediate the interaction with pUL11 and is required for pUL11 binding to T cells, indicating that pUL11 is a specific CD45 ligand. CD45 has a pivotal function regulating T cell signaling thresholds; in its absence, the Src family kinase Lck is inactive and signaling through the T cell receptor (TCR) is therefore shut off. In the presence of pUL11, several CD45-mediated functions were inhibited. The induction of tyrosine phosphorylation of multiple signaling proteins upon TCR stimulation was reduced and T cell proliferation was impaired. We therefore conclude that pUL11 has immunosuppressive properties, and that disruption of T cell function via inhibition of CD45 is a previously unknown immunomodulatory strategy of CMV

    The discovery, distribution, and evolution of viruses associated with drosophila melanogaster

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    Drosophila melanogaster is a valuable invertebrate model for viral infection and antiviral immunity, and is a focus for studies of insect-virus coevolution. Here we use a metagenomic approach to identify more than 20 previously undetected RNA viruses and a DNA virus associated with wild D. melanogaster. These viruses not only include distant relatives of known insect pathogens, but also novel groups of insect-infecting viruses. By sequencing virus-derived small RNAs we show that the viruses represent active infections of Drosophila. We find that the RNA viruses differ in the number and properties of their small RNAs, and we detect both siRNAs and a novel miRNA from the DNA virus. Analysis of small RNAs also allows us to identify putative viral sequences that lack detectable sequence similarity to known viruses. By surveying >2000 individually collected wild adult Drosophila we show that more than 30% of D. melanogaster carry a detectable virus, and more than 6% carry multiple viruses. However, despite a high prevalence of the Wolbachia endosymbiont—which is known to be protective against virus infections in Drosophila—we were unable to detect any relationship between the presence of Wolbachia and the presence of any virus. Using publicly available RNA-seq datasets we show that the community of viruses in Drosophila laboratories is very different from that seen in the wild, but that some of the newly discovered viruses are nevertheless widespread in laboratory lines and are ubiquitous in cell culture. By sequencing viruses from individual wild-collected flies we show that some viruses are shared between D. melanogaster and D. simulans. Our results provide an essential evolutionary and ecological context for host-virus interaction in Drosophila, and the newly reported viral sequences will help develop D. melanogaster further as a model for molecular and evolutionary virus research

    Genome-wide association study identifies 25 known breast cancer susceptibility loci as risk factors for triple-negative breast cancer

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    Triple-negative (TN) breast cancer is an aggressive subtype of breast cancer associated with a unique set of epidemiologic and genetic risk factors. We conducted a two-stage genome-wide association study of TN breast cancer (stage 1: 1529 TN cases, 3399 controls; stage 2: 2148 cases, 1309 controls) to identify loci that influence TN breast cancer risk. Variants in the 19p13.1 and PTHLH loci showed genome-wide significant associations (P < 5 × 10− 8) in stage 1 and 2 combined. Results also suggested a substantial enrichment of significantly associated variants among the single nucleotide polymorphisms (SNPs) analyzed in stage 2. Variants from 25 of 74 known breast cancer susceptibility loci were also associated with risk of TN breast cancer (P < 0.05). Associations with TN breast cancer were confirmed for 10 loci (LGR6, MDM4, CASP8, 2q35, 2p24.1, TERT-rs10069690, ESR1, TOX3, 19p13.1, RALY), and we identified associations with TN breast cancer for 15 additional breast cancer loci (P < 0.05: PEX14, 2q24.1, 2q31.1, ADAM29, EBF1, TCF7L2, 11q13.1, 11q24.3, 12p13.1, PTHLH, NTN4, 12q24, BRCA2, RAD51L1-rs2588809, MKL1). Further, two SNPs independent of previously reported signals in ESR1 [rs12525163 odds ratio (OR) = 1.15, P = 4.9 × 10− 4] and 19p13.1 (rs1864112 OR = 0.84, P = 1.8 × 10− 9) were associated with TN breast cancer. A polygenic risk score (PRS) for TN breast cancer based on known breast cancer risk variants showed a 4-fold difference in risk between the highest and lowest PRS quintiles (OR = 4.03, 95% confidence interval 3.46–4.70, P = 4.8 × 10− 69). This translates to an absolute risk for TN breast cancer ranging from 0.8% to 3.4%, suggesting that genetic variation may be used for TN breast cancer risk prediction

    Effects of antiplatelet therapy after stroke due to intracerebral haemorrhage (RESTART): a randomised, open-label trial

    Get PDF
    BACKGROUND: Antiplatelet therapy reduces the risk of major vascular events for people with occlusive vascular disease, although it might increase the risk of intracranial haemorrhage. Patients surviving the commonest subtype of intracranial haemorrhage, intracerebral haemorrhage, are at risk of both haemorrhagic and occlusive vascular events, but whether antiplatelet therapy can be used safely is unclear. We aimed to estimate the relative and absolute effects of antiplatelet therapy on recurrent intracerebral haemorrhage and whether this risk might exceed any reduction of occlusive vascular events. METHODS: The REstart or STop Antithrombotics Randomised Trial (RESTART) was a prospective, randomised, open-label, blinded endpoint, parallel-group trial at 122 hospitals in the UK. We recruited adults (≥18 years) who were taking antithrombotic (antiplatelet or anticoagulant) therapy for the prevention of occlusive vascular disease when they developed intracerebral haemorrhage, discontinued antithrombotic therapy, and survived for 24 h. Computerised randomisation incorporating minimisation allocated participants (1:1) to start or avoid antiplatelet therapy. We followed participants for the primary outcome (recurrent symptomatic intracerebral haemorrhage) for up to 5 years. We analysed data from all randomised participants using Cox proportional hazards regression, adjusted for minimisation covariates. This trial is registered with ISRCTN (number ISRCTN71907627). FINDINGS: Between May 22, 2013, and May 31, 2018, 537 participants were recruited a median of 76 days (IQR 29-146) after intracerebral haemorrhage onset: 268 were assigned to start and 269 (one withdrew) to avoid antiplatelet therapy. Participants were followed for a median of 2·0 years (IQR [1·0- 3·0]; completeness 99·3%). 12 (4%) of 268 participants allocated to antiplatelet therapy had recurrence of intracerebral haemorrhage compared with 23 (9%) of 268 participants allocated to avoid antiplatelet therapy (adjusted hazard ratio 0·51 [95% CI 0·25-1·03]; p=0·060). 18 (7%) participants allocated to antiplatelet therapy experienced major haemorrhagic events compared with 25 (9%) participants allocated to avoid antiplatelet therapy (0·71 [0·39-1·30]; p=0·27), and 39 [15%] participants allocated to antiplatelet therapy had major occlusive vascular events compared with 38 [14%] allocated to avoid antiplatelet therapy (1·02 [0·65-1·60]; p=0·92). INTERPRETATION: These results exclude all but a very modest increase in the risk of recurrent intracerebral haemorrhage with antiplatelet therapy for patients on antithrombotic therapy for the prevention of occlusive vascular disease when they developed intracerebral haemorrhage. The risk of recurrent intracerebral haemorrhage is probably too small to exceed the established benefits of antiplatelet therapy for secondary prevention. FUNDING: British Heart Foundation

    Exploring the role of smartphone apps for livestock farmers: data management, extension and informed decision making

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    Purpose: This paper establishes the attitude of Australian livestock farmers toward the use of mobile applications (apps) in farmer extension, training and on-farm decision making. It also determines levels of technology adoption of smartphones and agriculture app use, as well as identifies factors that may influence app adoption. Methodology: A quantitative approach was utilised in the analysis of data from four online surveys conducted in 2017 that were completed by a total 542 respondents. Findings: Respondents had high levels of smartphone ownership and general app use but significantly lower agricultural app use. Surveys revealed a strong positive attitude and keenness to use apps. Making more informed decisions, increasing efficiency, and accessing and recording important information were the most important reasons for agricultural app use. Practical Implications: Findings suggest a lack of relevant, useful, and easy to use apps for agriculture, or an issue with their value proposition. Theoretical Implications: The perceived technology adoption gap amongst Australian livestock farmers could not be substantiated. Established fundamental factors influencing technology adoption are relevant for agricultural app adoption, but other factors appear to be less relevant and there are new motivators to consider. Originality/Value: There is little peer-reviewed information on the adoption and use of agricultural apps by Australian farmers and a perception that farmers have lower levels of smartphone and app use. This paper assesses technology adoption levels and considers the farmer perspective in identifying factors influencing adoption

    Analysis of Livestock Industry App Technology Development and Adoption for Farmer Extension and Decision-Making

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    Mobile applications (apps) can be of great benefit to the way farmers record and access information, make more informed decisions, combine with other precision agriculture technologies, and play an important role in the delivery of farmer extension. There is little peerreviewed empirical information on Australian or international farmers' adoption and use of agricultural apps. Despite their widespread use, the literature also suggests that farmers have lower uptake of mobile device and app use than the general population. The first objective of this thesis was to review the current technology adoption and extension models and assess their relevance for the adoption of app technology for the livestock industry, particularly the sheep sector. The next objective was to establish the levels of technology adoption of smartphones and agricultural app use for Australian livestock farmers and what farm or farmer characteristics influence adoption. The next task was to assess the motivations or incentives for farmers to adopt agricultural apps in their farm businesses and finally evaluate the attitude of farmers towards the role of apps in extension and on-farm decision-making. Overall, the research project aimed to identify factors of importance to farmers that influence their decision-making processes for agricultural app uptake through directly asking farmers. Another aim was to identify factors and processes important to developing agricultural apps that underpin successful adoption. These results can form the basis of a development framework to guide the creation of agricultural apps targeting farmers as their end-users. This study uses a mixed-methods research methodology. Online quantitative surveys were conducted to establish smartphone ownership and agricultural app use levels and evaluate farmer attitudes towards the role of apps in farmer extension and decision-making. The study also identifies factors of importance to livestock farmers and other factors influencing app adoption. I held semi-structured key informant qualitative interviews with app development team members from industry research and development (R&amp;D) and private sector organisations. Analysis of the interviews identified key success factors for app adoption. An initial online survey (Survey 1) was completed by 392 respondents, including app users and non-app users, where 79% were sheep farmers. Subsequent surveys (Surveys 2–4) were completed by a total of 150 respondents, targeting the users of three Australian agricultural apps—RamSelect, Lifetime Ewe Management and Good Bulls—where 84.7% of respondents were farmers (sheep and dairy). Survey respondents generally had high smartphone and tablet ownership levels of between 91.9% and 97.9%. Mobile app use was also high among survey participants, with 83.4% for Survey 1 and 90.8% for Surveys 2–4. However, significantly lower rates of agricultural app use suggest either a lack of relevant, useful and easy to use apps for agriculture or an issue with the value proposition for app adoption. Survey 1 found that farmer age, use of advisers and farmer network participation significantly influenced farmer app adoption. However, when asked, farmers ranked networks and advisers of low influence when deciding to use an agricultural app. Older age brackets had lower levels of app adoption, but the level of adoption was still relatively high. Thus, age should not be viewed as a barrier to adoption or overlooked in R&amp;D and marketing. Developers and marketers of agricultural apps should also be wary of how they use farm advisers and farmer networks in their adoption plans. Although there was a positive relationship with higher levels of adoption, it may not be for previously thought reasons. All surveys revealed a strong positive farmer attitude towards using apps in farmer extension. The vast majority of participants see apps replacing some traditional extension methods or that apps would be useful tools to incorporate into programs. Participants demonstrated a similar positive attitude for the role of apps in on-farm decision-making. The combined response signifies a strong positive attitude to using apps in the livestock industry. Participants were asked to rank the importance of app attributes and reasons for app use. Participants identified usefulness, ease-of-use and a better way of doing something already done as the most important app attributes. Survey participants highlighted that making more informed decisions, increasing efficiency, accessing and recording important information and saving time were the most important reasons for agricultural app use. The top reason for not using an agricultural app was apps taking too long to set up and learn how to use. The interviewing of agricultural app development teams helped identify key factors within the app development process that led to apps being more likely to achieve successful adoption. These factors include beginning the process with a verified end-user 'pain point', validating the app solution, clearly defining the app value proposition, having end-users engaged throughout the whole development process and implementing advanced systems to utilise feedback to enable customer success continual product improvements. Furthermore, some areas of R&amp;D organisation product development and funding models hinder the success of app adoption that had a commercialisation goal. This study contributes to the literature by establishing both levels of technology adoption of agricultural apps and key determinants of app adoption in the Australian livestock industry. While the study was conducted in Australia, there is limited peer-reviewed information on agricultural app adoption more broadly. This study adds value to the small number of existing international studies. The study considers farm and farmer characteristics that influence agricultural app adoption and uniquely identifies what motivates and influences farmers to adopt from a farmer perspective, as well as their attitudes towards the role of apps in farmer extension and on-farm decision-making. While many aspects of existing DST adoption frameworks and established technology adoption models are still relevant to adopting agricultural apps, no single model or framework effectively encapsulates the factors and processes needed, or the new app-specific findings reported in this study. On this basis, a framework is proposed based on the research conducted, identifying why farmers use agricultural apps, factors that influence app adoption, and the factors and processes within app development that lead to apps being more successful in the marketplace. The agricultural app adoption framework is intended for app developers and providers, with farmers as their target users, particularly livestock producers, to reach greater levels of adoption success. The framework can also inform funders, extension agents and policymakers on the crucial elements to be considered in developing successful apps for farmers. This study also highlights areas for further investigation, such as the need to better understand the relationship between farmer network participation and adviser use with higher levels of technology adoption and how best to incorporate apps into new and existing farmer extension programs. There is also potential for using other product development and funding models within R&amp;D organisations to improve commercialisation success and higher levels of app adoption
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