359 research outputs found

    Comparing treatment fidelity between study arms of a randomized controlled clinical trial for stroke family caregivers

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    OBJECTIVE: To compare treatment fidelity among treatment arms in the Telephone Assessment and Skill-Building Kit study for stroke caregivers (TASK II) with respect to: 1) protocol adherence; 2) intervention dosage and 3) nurse intervener perspectives. DESIGN: A randomized controlled clinical trial design. SETTING: Urban, community, midwestern United States. SUBJECTS: A total of 254 stroke caregivers (mean ±SD age, 54.4 ±11.8 years), 55 (22.0%) males and 199 (78.4%) females) randomized to the TASK II intervention (n=123) or an Information, Support, and Referral comparison group (n=131). INTERVENTIONS: TASK II participants received the TASK II Resource Guide; Information, Support, and Referral participants received a standard caregiver brochure. At approximately 8 weeks after discharge, both groups received 8 weekly calls from a nurse, with a booster call 4 weeks later. MEASURES: Protocol adherence was evaluated with the TASK II Checklist for Monitoring Adherence. Intervention dosage was measured by the number of minutes caregivers spent reading materials and talking with the nurse. Nurse intervener perspectives were obtained through focus groups. RESULTS: Protocol adherence was 80% for the TASK II and 92% for the Information, Support, and Referral. As expected, intervention dosage differed between TASK II and Information, Support, and Referral with respect to caregiver time spent reading materials (t=-6.49; P<.001) and talking with the nurse (t=-7.38; P<.001). Focus groups with nurses yielded further evidence for treatment fidelity and recommendations for future trials. CONCLUSIONS: These findings substantiate treatment fidelity in both study arms of the TASK II stroke caregiver intervention trial (NIH R01NR010388; ClinicalTrials.govNCT01275495)

    Activated mutant NRasQ61K drives aberrant melanocyte signaling, survival, and invasiveness via a rac1-Dependent mechanism

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    Around a fifth of melanomas exhibit an activating mutation in the oncogene NRas that confers constitutive signaling to proliferation and promotes tumor initiation. NRas signals downstream of the major melanocyte tyrosine kinase receptor c-kit and activated NRas results in increased signaling via the extracellular signal–regulated kinase (ERK)/MAPK/ERK kinase/mitogen-activated protein kinase (MAPK) pathways to enhance proliferation. The Ras oncogene also activates signaling via the related Rho GTPase Rac1, which can mediate growth, survival, and motility signaling. We tested the effects of activated NRasQ61K on the proliferation, motility, and invasiveness of melanoblasts and melanocytes in the developing mouse and ex vivo explant culture as well as in a melanoma transplant model. We find an important role for Rac1 downstream of NRasQ61K in mediating dermal melanocyte survival in vivo in mouse, but surprisingly NRasQ61K does not appear to affect melanoblast motility or proliferation during mouse embryogenesis. We also show that genetic deletion or pharmacological inhibition of Rac1 in NRasQ61K induced melanoma suppresses tumor growth, lymph node spread, and tumor cell invasiveness, suggesting a potential value for Rac1 as a therapeutic target for activated NRas-driven tumor growth and invasiveness

    Airway epithelium respiratory illnesses and allergy (AERIAL) birth cohort: Study protocol

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    Introduction: Recurrent wheezing disorders including asthma are complex and heterogeneous diseases that affect up to 30% of all children, contributing to a major burden on children, their families, and global healthcare systems. It is now recognized that a dysfunctional airway epithelium plays a central role in the pathogenesis of recurrent wheeze, although the underlying mechanisms are still not fully understood. This prospective birth cohort aims to bridge this knowledge gap by investigating the influence of intrinsic epithelial dysfunction on the risk for developing respiratory disorders and the modulation of this risk by maternal morbidities, in utero exposures, and respiratory exposures in the first year of life. Methods: The Airway Epithelium Respiratory Illnesses and Allergy (AERIAL) study is nested within the ORIGINS Project and will monitor 400 infants from birth to 5 years. The primary outcome of the AERIAL study will be the identification of epithelial endotypes and exposure variables that influence the development of recurrent wheezing, asthma, and allergic sensitisation. Nasal respiratory epithelium at birth to 6 weeks, 1, 3, and 5 years will be analysed by bulk RNA-seq and DNA methylation sequencing. Maternal morbidities and in utero exposures will be identified on maternal history and their effects measured through transcriptomic and epigenetic analyses of the amnion and newborn epithelium. Exposures within the first year of life will be identified based on infant medical history as well as on background and symptomatic nasal sampling for viral PCR and microbiome analysis. Daily temperatures and symptoms recorded in a study-specific Smartphone App will be used to identify symptomatic respiratory illnesses. Discussion: The AERIAL study will provide a comprehensive longitudinal assessment of factors influencing the association between epithelial dysfunction and respiratory morbidity in early life, and hopefully identify novel targets for diagnosis and early intervention

    Physiological, Biochemical, and Transcriptional Responses to Single and Combined Abiotic Stress in Stress-Tolerant and Stress-Sensitive Potato Genotypes

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    Potato production is often constrained by abiotic stresses such as drought and high temperatures which are often present in combination. In the present work, we aimed to identify key mechanisms and processes underlying single and combined abiotic stress tolerance by comparative analysis of tolerant and susceptible cultivars. Physiological data indicated that the cultivars Desiree and Unica were stress tolerant while Agria and Russett Burbank were stress susceptible. Abiotic stress caused a greater reduction of photosynthetic carbon assimilation in the susceptible cultivars which was associated with a lower leaf transpiration rate. Oxidative stress, as estimated by the accumulation of malondialdehyde was not induced by stress treatments in any of the genotypes with the exception of drought stress in Russett Burbank. Stress treatment resulted in increases in ascorbate peroxidase activity in all cultivars except Agria which increased catalase activity in response to stress. Transcript profiling highlighted a decrease in the abundance of transcripts encoding proteins associated with PSII light harvesting complex in stress tolerant cultivars. Furthermore, stress tolerant cultivars accumulated fewer transcripts encoding a type-1 metacaspase implicated in programmed cell death. Stress tolerant cultivars exhibited stronger expression of genes associated with plant growth and development, hormone metabolism and primary and secondary metabolism than stress susceptible cultivars. Metabolite profiling revealed accumulation of proline in all genotypes following drought stress that was partially suppressed in combined heat and drought. On the contrary, the sugar alcohols inositol and mannitol were strongly accumulated under heat and combined heat and drought stress while galactinol was most strongly accumulated under drought. Combined heat and drought also resulted in the accumulation of Valine, isoleucine, and lysine in all genotypes. These data indicate that single and multiple abiotic stress tolerance in potato is associated with a maintenance of CO2 assimilation and protection of PSII by a reduction of light harvesting capacity. The data further suggests that stress tolerant cultivars suppress cell death and maintain growth and development via fine tuning of hormone signaling, and primary and secondary metabolism. This study highlights potential targets for the development of stress tolerant potato cultivars

    Healthy Hearts – A community-based primary prevention programme to reduce coronary heart disease

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    Background The ten year probability of cardiovascular events can be calculated, but many people are unaware of their risk and unclear how to reduce it. The aim of this study was to assess whether a community based intervention, for men and women aged between 45 and 64 years without pre-existing coronary heart disease, would reduce their Framingham scores when reassessed one year later. Methods Individuals in the relevant age group from a defined geographical area were sent an invitation to attend for an assessment of their cardiovascular risk. Individuals with pre-existing cardiovascular disease or terminal illness were excluded. The invitation was in the form of a "Many Happy Returns" card with a number of self-screening questions including the question, "If you put the enclosed string around your waist, is it too short?" The card contained a red 80 cm piece of string in the case of women, or a green 90 cm piece of string in the case of men. At the assessment appointment, Framingham scores were calculated and a printout was given to each individual. Advice was provided for relevant risk factors identified using agreed guidelines. If appropriate, onward referral was also made to a GP, dietician, an exercise referral scheme, or to smoking cessation services, using a set of guidelines. Individuals were sent a second invitation one year later to return for re-assessment. Results and discussion 2031 individuals were asked to self-assess their eligibility to participate, 596 individuals attended for assessment and 313 of these attended for follow-up one year later. The mean reduction in the Framingham risk score, was significantly lower at one year (0.876, 95% CI 0.211 to 1.541, p = 0.01). The mean 10-year risk of CHD at baseline was 13.14% (SD 9.18) and had fallen at follow-up to 12.34% (SD 8.71), a mean reduction of 6.7% of the initial 10-year Framingham risk. If sustained, the estimated NNT to prevent each year of CHD would be 1141 (95% CI 4739 to 649) individual appointments. Conclusion This community intervention for primary prevention of CHD reduces Framingham risk scores at one year in those who engage with the programme

    Large-scale genome-wide association studies and meta-analyses of longitudinal change in adult lung function.

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    BACKGROUND: Genome-wide association studies (GWAS) have identified numerous loci influencing cross-sectional lung function, but less is known about genes influencing longitudinal change in lung function. METHODS: We performed GWAS of the rate of change in forced expiratory volume in the first second (FEV1) in 14 longitudinal, population-based cohort studies comprising 27,249 adults of European ancestry using linear mixed effects model and combined cohort-specific results using fixed effect meta-analysis to identify novel genetic loci associated with longitudinal change in lung function. Gene expression analyses were subsequently performed for identified genetic loci. As a secondary aim, we estimated the mean rate of decline in FEV1 by smoking pattern, irrespective of genotypes, across these 14 studies using meta-analysis. RESULTS: The overall meta-analysis produced suggestive evidence for association at the novel IL16/STARD5/TMC3 locus on chromosome 15 (P  =  5.71 × 10(-7)). In addition, meta-analysis using the five cohorts with ≥3 FEV1 measurements per participant identified the novel ME3 locus on chromosome 11 (P  =  2.18 × 10(-8)) at genome-wide significance. Neither locus was associated with FEV1 decline in two additional cohort studies. We confirmed gene expression of IL16, STARD5, and ME3 in multiple lung tissues. Publicly available microarray data confirmed differential expression of all three genes in lung samples from COPD patients compared with controls. Irrespective of genotypes, the combined estimate for FEV1 decline was 26.9, 29.2 and 35.7 mL/year in never, former, and persistent smokers, respectively. CONCLUSIONS: In this large-scale GWAS, we identified two novel genetic loci in association with the rate of change in FEV1 that harbor candidate genes with biologically plausible functional links to lung function

    Predicting sepsis severity at first clinical presentation:The role of endotypes and mechanistic signatures

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    BACKGROUND: Inter-individual variability during sepsis limits appropriate triage of patients. Identifying, at first clinical presentation, gene expression signatures that predict subsequent severity will allow clinicians to identify the most at-risk groups of patients and enable appropriate antibiotic use. METHODS: Blood RNA-Seq and clinical data were collected from 348 patients in four emergency rooms (ER) and one intensive-care-unit (ICU), and 44 healthy controls. Gene expression profiles were analyzed using machine learning and data mining to identify clinically relevant gene signatures reflecting disease severity, organ dysfunction, mortality, and specific endotypes/mechanisms. FINDINGS: Gene expression signatures were obtained that predicted severity/organ dysfunction and mortality in both ER and ICU patients with accuracy/AUC of 77–80%. Network analysis revealed these signatures formed a coherent biological program, with specific but overlapping mechanisms/pathways. Given the heterogeneity of sepsis, we asked if patients could be assorted into discrete groups with distinct mechanisms (endotypes) and varying severity. Patients with early sepsis could be stratified into five distinct and novel mechanistic endotypes, named Neutrophilic-Suppressive/NPS, Inflammatory/INF, Innate-Host-Defense/IHD, Interferon/IFN, and Adaptive/ADA, each based on ∼200 unique gene expression differences, and distinct pathways/mechanisms (e.g., IL6/STAT3 in NPS). Endotypes had varying overall severity with two severe (NPS/INF) and one relatively benign (ADA) groupings, consistent with reanalysis of previous endotype studies. A 40 gene-classification tool (accuracy=96%) and several gene-pairs (accuracy=89–97%) accurately predicted endotype status in both ER and ICU validation cohorts. INTERPRETATION: The severity and endotype signatures indicate that distinct immune signatures precede the onset of severe sepsis and lethality, providing a method to triage early sepsis patients

    Airway epithelium respiratory illnesses and allergy (AERIAL) birth cohort: study protocol

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    IntroductionRecurrent wheezing disorders including asthma are complex and heterogeneous diseases that affect up to 30% of all children, contributing to a major burden on children, their families, and global healthcare systems. It is now recognized that a dysfunctional airway epithelium plays a central role in the pathogenesis of recurrent wheeze, although the underlying mechanisms are still not fully understood. This prospective birth cohort aims to bridge this knowledge gap by investigating the influence of intrinsic epithelial dysfunction on the risk for developing respiratory disorders and the modulation of this risk by maternal morbidities, in utero exposures, and respiratory exposures in the first year of life.MethodsThe Airway Epithelium Respiratory Illnesses and Allergy (AERIAL) study is nested within the ORIGINS Project and will monitor 400 infants from birth to 5 years. The primary outcome of the AERIAL study will be the identification of epithelial endotypes and exposure variables that influence the development of recurrent wheezing, asthma, and allergic sensitisation. Nasal respiratory epithelium at birth to 6 weeks, 1, 3, and 5 years will be analysed by bulk RNA-seq and DNA methylation sequencing. Maternal morbidities and in utero exposures will be identified on maternal history and their effects measured through transcriptomic and epigenetic analyses of the amnion and newborn epithelium. Exposures within the first year of life will be identified based on infant medical history as well as on background and symptomatic nasal sampling for viral PCR and microbiome analysis. Daily temperatures and symptoms recorded in a study-specific Smartphone App will be used to identify symptomatic respiratory illnesses.DiscussionThe AERIAL study will provide a comprehensive longitudinal assessment of factors influencing the association between epithelial dysfunction and respiratory morbidity in early life, and hopefully identify novel targets for diagnosis and early intervention

    Implementation of a health care policy: An analysis of barriers and facilitators to practice change

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    BACKGROUND: Governments often create policies that rely on implementation by arms length organizations and require practice changes on the part of different segments of the health care system without understanding the differences in and complexities of these agencies. In 2000, in response to publicity about the shortening length of postpartum hospital stay, the Ontario government created a universal program offering up to a 60-hour postpartum stay and a public health follow-up to mothers and newborn infants. The purpose of this paper is to examine how a health policy initiative was implemented in two different parts of a health care system and to analyze the barriers and facilitators to achieving practice change. METHODS: The data reported came from two studies of postpartum health and service use in Ontario Canada. Data were collected from newly delivered mothers who had uncomplicated vaginal deliveries. The study samples were drawn from the same five purposefully selected hospitals for both studies. Questionnaires prior to discharge and structured telephone interviews at 4-weeks post discharge were used to collect data before and after policy implementation. Qualitative data were collected using focus groups with hospital and community-based health care practitioners and administrators at each site. RESULTS: In both studies, the respondents reflected a population of women who experienced an "average" or non-eventful hospital-based, singleton vaginal delivery. The findings of the second study demonstrated wide variance in implementation of the offer of a 60-hour stay among the sites and focus groups revealed that none of the hospitals acknowledged the 60-hour stay as an official policy. The uptake of the offer of a 60-hour stay was unrelated to the rate of offer. The percentage of women with a hospital stay of less than 25 hours and the number with the guideline that the call be within 48 hours of hospital discharge. Public health telephone contact was high although variable in relation to compliance the guideline that the call be within 48 hours of hospital discharge. Home visits were offered at consistently high rates. CONCLUSION: Policy enactment is sometimes inadequate to stimulate practice changes in health care. Policy as a tool for practice change must thoughtfully address the organizational, professional, and social contexts within which the policy is to be implemented. These contexts can either facilitate or block implementation. Our examination of Ontario's universal postpartum program provides an example of differential implementation of a common policy intended to change post-natal care practices that reflects the differential influence of context on implementation

    Evolutionary analysis and molecular dissection of caveola biogenesis

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    Caveolae are an abundant feature of mammalian cells. Integral membrane proteins called caveolins drive the formation of caveolae but the precise mechanisms underlying caveola formation, and the origin of caveolae and caveolins during evolution, are unknown
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