27 research outputs found

    Inhibition of αvβ5 Integrin Attenuates Vascular Permeability and Protects against Renal Ischemia-Reperfusion Injury

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    Ischemia-reperfusion injury (IRI) is a leading cause of AKI. This common clinical complication lacks effective therapies and can lead to the development of CKD. The αvβ5 integrin may have an important role in acute injury, including septic shock and acute lung injury. To examine its function in AKI, we utilized a specific function-blocking antibody to inhibit αvβ5 in a rat model of renal IRI. Pretreatment with this anti-αvβ5 antibody significantly reduced serum creatinine levels, diminished renal damage detected by histopathologic evaluation, and decreased levels of injury biomarkers. Notably, therapeutic treatment with the αvβ5 antibody 8 hours after IRI also provided protection from injury. Global gene expression profiling of post-ischemic kidneys showed that αvβ5 inhibition affected established injury markers and induced pathway alterations previously shown to be protective. Intravital imaging of post-ischemic kidneys revealed reduced vascular leak with αvβ5 antibody treatment. Immunostaining for αvβ5 in the kidney detected evident expression in perivascular cells, with negligible expression in the endothelium. Studies in a three-dimensional microfluidics system identified a pericyte-dependent role for αvβ5 in modulating vascular leak. Additional studies showed αvβ5 functions in the adhesion and migration of kidney pericytes in vitro Initial studies monitoring renal blood flow after IRI did not find significant effects with αvβ5 inhibition; however, future studies should explore the contribution of vasomotor effects. These studies identify a role for αvβ5 in modulating injury-induced renal vascular leak, possibly through effects on pericyte adhesion and migration, and reveal αvβ5 inhibition as a promising therapeutic strategy for AKI

    Classification of patient-safety incidents in primary care

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    Primary care lags behind secondary care in the reporting of, and learning from, incidents that put patient safety at risk. In primary care, there is no universally agreed approach to classifying the severity of harm arising from such patient-safety incidents. This lack of an agreed approach limits learning that could lead to the prevention of injury to patients. In a review of research on patient safety in primary care, we identified 21 existing approaches to the classification of harm severity. Using the World Health Organization's (WHO's) International Classification for Patient Safety as a reference, we undertook a framework analysis of these approaches. We then developed a new system for the classification of harm severity. To assess and classify harm, most existing approaches use measures of symptom duration (11/21), symptom severity (11/21) and/or the level of intervention required to manage the harm (14/21). However, few of these approaches account for the deleterious effects of hospitalization or the psychological stress that may be experienced by patients and/or their relatives. The new classification system we developed builds on WHO's International Classification for Patient Safety and takes account not only of hospitalization and psychological stress but also of so-called near misses and uncertain outcomes. The constructs we have outlined have the potential to be applied internationally, across primary-care settings, to improve both the detection and prevention of incidents that cause the most severe harm to patients

    The genetic heterogeneity and mutational burden of engineered melanomas in zebrafish models.

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    BACKGROUND: Melanoma is the most deadly form of skin cancer. Expression of oncogenic BRAF or NRAS, which are frequently mutated in human melanomas, promote the formation of nevi but are not sufficient for tumorigenesis. Even with germline mutated p53, these engineered melanomas present with variable onset and pathology, implicating additional somatic mutations in a multi-hit tumorigenic process. RESULTS: To decipher the genetics of these melanomas, we sequence the protein coding exons of 53 primary melanomas generated from several BRAF(V600E) or NRAS(Q61K) driven transgenic zebrafish lines. We find that engineered zebrafish melanomas show an overall low mutation burden, which has a strong, inverse association with the number of initiating germline drivers. Although tumors reveal distinct mutation spectrums, they show mostly C > T transitions without UV light exposure, and enrichment of mutations in melanogenesis, p53 and MAPK signaling. Importantly, a recurrent amplification occurring with pre-configured drivers BRAF(V600E) and p53-/- suggests a novel path of BRAF cooperativity through the protein kinase A pathway. CONCLUSION: This is the first analysis of a melanoma mutational landscape in the absence of UV light, where tumors manifest with remarkably low mutation burden and high heterogeneity. Genotype specific amplification of protein kinase A in cooperation with BRAF and p53 mutation suggests the involvement of melanogenesis in these tumors. This work is important for defining the spectrum of events in BRAF or NRAS driven melanoma in the absence of UV light, and for informed exploitation of models such as transgenic zebrafish to better understand mechanisms leading to human melanoma formation

    Facilitating the transition of young people with long-term conditions through health services from childhood to adulthood: the Transition research programme

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    Background: As young people with long-term conditions move from childhood to adulthood, their health may deteriorate and their social participation may reduce. ‘Transition’ is the ‘process’ that addresses the medical, psychosocial and educational needs of young people during this time. ‘Transfer’ is the ‘event’ when medical care moves from children’s to adults’ services. In a typical NHS Trust serving a population of 270,000, approximately 100 young people with long-term conditions requiring secondary care reach the age of 16 years each year. As transition extends over about 7 years, the number in transition at any time is approximately 700. Objectives: Purpose – to promote the health and well-being of young people with long-term conditions by generating evidence to enable NHS commissioners and providers to facilitate successful health-care transition. Objectives – (1) to work with young people to determine what is important in their transitional health care, (2) to identify the effective and efficient features of transitional health care and (3) to determine how transitional health care should be commissioned and provided. Design, settings and participants: Three work packages addressed each objective. Objective 1. (i) A young people’s advisory group met monthly throughout the programme. (ii) It explored the usefulness of patient-held health information. (iii) A ‘Q-sort’ study examined how young people approached transitional health care. Objective 2. (i) We followed, for 3 years, 374 young people with type 1 diabetes mellitus (150 from five sites in England), autism spectrum disorder (118 from four sites in England) or cerebral palsy (106 from 18 sites in England and Northern Ireland). We assessed whether or not nine proposed beneficial features (PBFs) of transitional health care predicted better outcomes. (ii) We interviewed a subset of 13 young people about their transition. (iii) We undertook a discrete choice experiment and examined the efficiency of illustrative models of transition. Objective 3. (i) We interviewed staff and observed meetings in three trusts to identify the facilitators of and barriers to introducing developmentally appropriate health care (DAH). We developed a toolkit to assist the introduction of DAH. (ii) We undertook a literature review, interviews and site visits to identify the facilitators of and barriers to commissioning transitional health care. (iii) We synthesised learning on ‘what’ and ‘how’ to commission, drawing on meetings with commissioners. Main outcome measures: Participation in life situations, mental well-being, satisfaction with services and condition-specific outcomes. Strengths: This was a longitudinal study with a large sample; the conditions chosen were representative; non-participation and attrition appeared unlikely to introduce bias; the research on commissioning was novel; and a young person’s group was involved. Limitations: There is uncertainty about whether or not the regions and trusts in the longitudinal study were representative; however, we recruited from 27 trusts widely spread over England and Northern Ireland, which varied greatly in the number and variety of the PBFs they offered. The quality of delivery of each PBF was not assessed. Owing to the nature of the data, only exploratory rather than strict economic modelling was undertaken. Results and conclusions: (1) Commissioners and providers regarded transition as the responsibility of children’s services. This is inappropriate, given that transition extends to approximately the age of 24 years. Our findings indicate an important role for commissioners of adults’ services to commission transitional health care, in addition to commissioners of children’s services with whom responsibility for transitional health care currently lies. (2) DAH is a crucial aspect of transitional health care. Our findings indicate the importance of health services being commissioned to ensure that providers deliver DAH across all health-care services, and that this will be facilitated by commitment from senior provider and commissioner leaders. (3) Good practice led by enthusiasts rarely generalised to other specialties or to adults’ services. This indicates the importance of NHS Trusts adopting a trust-wide approach to implementation of transitional health care. (4) Adults’ and children’s services were often not joined up. This indicates the importance of adults’ clinicians, children’s clinicians and general practitioners planning transition procedures together. (5) Young people adopted one of four broad interaction styles during transition: ‘laid back’, ‘anxious’, ‘wanting autonomy’ or ‘socially oriented’. Identifying a young person’s style would help personalise communication with them. (6) Three PBFs of transitional health care were significantly associated with better outcomes: ‘parental involvement, suiting parent and young person’, ‘promotion of a young person’s confidence in managing their health’ and ‘meeting the adult team before transfer’. (7) Maximal service uptake would be achieved by services encouraging appropriate parental involvement with young people to make decisions about their care. A service involving ‘appropriate parental involvement’ and ‘promotion of confidence in managing one’s health’ may offer good value for money. Future work: How might the programme’s findings be implemented by commissioners and health-care providers? What are the most effective ways for primary health care to assist transition and support young people after transfer

    Monitoring activities of teenagers to comprehend their habits: study protocol for a mixed-methods cohort study

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    Abstract: Background: Efforts to increase physical activity in youth need to consider which activities are most likely to be sustained over time in order to promote lifelong participation in physical activity. The Monitoring Activities of Teenagers to Comprehend their Habits (MATCH) study is a prospective cohort study that uses quantitative and qualitative methods to develop new knowledge on the sustainability of specific physical activities. Methods/design: Eight hundred and forty-three grade 5 and 6 students recruited from 17 elementary schools in New Brunswick, Canada, are followed-up three times per year. At each survey cycle, participants complete self-report questionnaires in their classroom under the supervision of trained data collectors. A sub-sample of 24 physically active students is interviewed annually using a semi-structured interview protocol. Parents (or guardians) complete telephone administered questionnaires every two years, and a health and wellness school audit is completed for each school. Discussion: MATCH will provide a description of the patterns of participation in specific physical activities in youth, and enable identification of the determinants of maintenance, decline, and uptake of participation in each activity. These data will inform the development of interventions that take into account which activities are the most likely to be maintained and why activities are maintained or dropped

    Increasing frailty is associated with higher prevalence and reduced recognition of delirium in older hospitalised inpatients: results of a multi-centre study

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    Purpose: Delirium is a neuropsychiatric disorder delineated by an acute change in cognition, attention, and consciousness. It is common, particularly in older adults, but poorly recognised. Frailty is the accumulation of deficits conferring an increased risk of adverse outcomes. We set out to determine how severity of frailty, as measured using the CFS, affected delirium rates, and recognition in hospitalised older people in the United Kingdom. Methods: Adults over 65 years were included in an observational multi-centre audit across UK hospitals, two prospective rounds, and one retrospective note review. Clinical Frailty Scale (CFS), delirium status, and 30-day outcomes were recorded. Results: The overall prevalence of delirium was 16.3% (483). Patients with delirium were more frail than patients without delirium (median CFS 6 vs 4). The risk of delirium was greater with increasing frailty [OR 2.9 (1.8–4.6) in CFS 4 vs 1–3; OR 12.4 (6.2–24.5) in CFS 8 vs 1–3]. Higher CFS was associated with reduced recognition of delirium (OR of 0.7 (0.3–1.9) in CFS 4 compared to 0.2 (0.1–0.7) in CFS 8). These risks were both independent of age and dementia. Conclusion: We have demonstrated an incremental increase in risk of delirium with increasing frailty. This has important clinical implications, suggesting that frailty may provide a more nuanced measure of vulnerability to delirium and poor outcomes. However, the most frail patients are least likely to have their delirium diagnosed and there is a significant lack of research into the underlying pathophysiology of both of these common geriatric syndromes

    A Genome-wide Haploid Genetic Screen Identifies Regulators of Glutathione Abundance and Ferroptosis Sensitivity

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    Summary: The tripeptide glutathione suppresses the iron-dependent, non-apoptotic cell death process of ferroptosis. How glutathione abundance is regulated in the cell and how this regulation alters ferroptosis sensitivity is poorly understood. Using genome-wide human haploid genetic screening technology coupled to fluorescence-activated cell sorting (FACS), we directly identify genes that regulate intracellular glutathione abundance and characterize their role in ferroptosis regulation. Disruption of the ATP binding cassette (ABC)-family transporter multidrug resistance protein 1 (MRP1) prevents glutathione efflux from the cell and strongly inhibits ferroptosis. High levels of MRP1 expression decrease sensitivity to certain pro-apoptotic chemotherapeutic drugs, while collaterally sensitizing to all tested pro-ferroptotic agents. By contrast, disruption of KEAP1 and NAA38, leading to the stabilization of the transcription factor NRF2, increases glutathione levels but only weakly protects from ferroptosis. This is due in part to concomitant NRF2-mediated upregulation of MRP1. These results pinpoint glutathione efflux as an unanticipated regulator of ferroptosis sensitivity. : Glutathione suppresses the non-apoptotic cell death process of ferroptosis. Using genome-wide human haploid cell mutagenesis and FACS-based detection, Cao et al. identify negative regulators of intracellular glutathione abundance that affect glutathione efflux and NRF2 protein levels, altering ferroptosis sensitivity. Keywords: ROS, metabolite efflux, multidrug resistance, ferroptosis, necrosis, cancer, glutathione, iron, collateral sensitivit
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