5,514 research outputs found

    Mutant p53 cancers reprogram macrophages to tumor supporting macrophages via exosomal miR-1246

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    TP53 mutants (mutp53) are involved in the pathogenesis of most human cancers. Specific mutp53 proteins gain oncogenic functions (GOFs) distinct from the tumor suppressor activity of the wild-type protein. Tumor-associated macrophages (TAMs), a hallmark of solid tumors, are typically correlated with poor prognosis. Here, we report a non-cell-autonomous mechanism, whereby human mutp53 cancer cells reprogram macrophages to a tumor supportive and anti-inflammatory state. The colon cancer cells harboring GOF mutp53 selectively shed miR-1246-enriched exosomes. Uptake of these exosomes by neighboring macrophages triggers their miR-1246-dependent reprogramming into a cancerpromoting state. Mutp53-reprogammed TAMs favor anti-inflammatory immunosuppression with increased activity of TGF-β. These findings, associated with poor survival in colon cancer patients, strongly support a microenvironmental GOF role for mutp53 in actively engaging the immune system to promote cancer progression and metastasis

    Predicting Incremental and Future Visual Change in Neovascular Age-Related Macular Degeneration Using Deep Learning

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    PURPOSE: To evaluate the predictive utility of quantitative imaging biomarkers, acquired automatically from optical coherence tomography (OCT) scans, of cross-sectional and future visual outcomes of patients with neovascular age-related macular degeneration (AMD) starting anti-vascular endothelial growth factor (VEGF) therapy. DESIGN: Retrospective cohort study. PARTICIPANTS: Treatment-naïve, first-treated eyes of patients with neovascular AMD between 2007 and 2017 at Moorfields Eye Hospital (a large, UK single-centre) undergoing anti-VEGF therapy METHODS: Automatic segmentation was carried out by applying a deep learning segmentation algorithm to 137,379 OCT scans from 6467 eyes of 3261 patients with neovascular AMD. After applying selection criteria 926 eyes of 926 patients were taken forward for analysis. MAIN OUTCOME MEASURES: Correlation coefficients (R2) and mean absolute error (MAE) between quantitative OCT (qOCT) parameters and cross-sectional visual-function. The predictive value of these parameters for short-term visual change i.e. incremental visual acuity [VA] resulting from an individual injection, as well as, VA at distant timepoints (up to 12 months post-baseline). RESULTS: VA at distant timepoints could be predicted: R2 0.80 (MAE 5.0 ETDRS letters) and R2 0.7 (MAE 7.2) post-injection 3 and at 12 months post-baseline (both p < 0.001), respectively. Best performing models included both baseline qOCT parameters and treatment-response. Furthermore, we present proof-of-principle evidence that the incremental change in VA from an injection can be predicted: R2 0.14 (MAE 5.6) for injection 2 and R2 0.11 (MAE 5.0) for injection 3 (both p < 0.001). CONCLUSIONS: Automatic segmentation enables rapid acquisition of quantitative and reproducible OCT biomarkers with potential to inform treatment decisions in the care of neovascular AMD. This furthers development of point-of-care decision-aid systems for personalized medicine

    Mycotic aneurysm of the posterior tibial artery – a rare complication of bacterial endocarditis: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Distal arterial embolisation and subsequent aneurysm formation are rare occurrences and most are secondary to trauma. We have found no case reports that describe posterior tibial aneurysm formation secondary to bacterial endocarditis.</p> <p>Case presentation</p> <p>We report the case of a 47-year-old Caucasian man who, 2 years after an episode of subacute bacterial endocarditis, presented with signs and symptoms consistent with posterior tibial aneurysm formation.</p> <p>Conclusion</p> <p>Posterior tibial aneurysm formation is a rare occurrence, most commonly occurring after trauma and, although other causes have been described, to our knowledge, endocarditis has not been implicated before, and as such should therefore be borne in mind when dealing with cases where no obvious aetiology is evident.</p

    Interim prostacyclin therapy for an isolated disconnected pulmonary artery: a case report

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    Introduction: Disconnected pulmonary arteries are unusual and may result in pulmonary hypertension with acute right heart failure. Case presentation: We report a case of a three-month-old Asian girl who presented with heart failure and severe pulmonary hypertension due to a disconnected right pulmonary artery. An epoprostenol (prostacyclin) infusion was instrumental in lowering pulmonary artery pressures and stabilizing the child prior to surgery. Conclusions: This is, to the best of our knowledge, the first report of successful prostacyclin usage in such a situation.peer-reviewe

    A grounded theory of type 2 diabetes prevention and risk perception

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    Objective Type 2 diabetes (T2D) prevention programmes should target high‐risk groups. Previous research has highlighted minimal engagement in such services from South Asian (SA) people. Given SA's elevated risk of T2D, there is a need to understand their perceptions, risks, and beliefs about T2D. Design This study aimed to assess T2D risk perception within a community sample of SA people using Grounded Theory methodology. Specifically, health beliefs were assessed, and we explored how these beliefs affected their T2D risk perceptions. Method Twenty SA participants (mean age = 38 years) without a diagnosis of T2D were recruited from community and religious settings across the North West of England. In line with grounded theory (Strauss & Corbin, 1990, Basics of qualitative research: Grounded theory procedures and techniques. Newbury Park: Sage Publications), data collection and analysis coincided. Results The superordinate category of Culturally Situated Risk Perception incorporated a complex psychological understanding of the formation of T2D risk perception, which takes into account the social, cultural, and community‐based environmental factors. This superordinate category was explained via two core categories (1) Diminished Responsibility, informed by sub‐categories of Destiny and Heredity, and (2) Influencing Healthy Lifestyle Behaviours, informed by sub‐categories of Socio‐cultural and Environmental. Conclusion This study investigated risk perception of T2D within the SA community. When considering health prevention in the context of an individual’s culture, we need to consider the social context in which they live. Failure to acknowledge the cultural‐situated T2D risk perception relevant to health promotion and illness messages may account for the issues identified with health care engagement in the SA population

    Cultural Identity Conflict Informs Engagement with Self-Management Behaviours for South Asian Patients Living with Type-2 Diabetes: A Critical Interpretative Synthesis of Qualitative Research Studies

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    The prevalence of type-2 diabetes (T2D) is increasing, particularly among South Asian (SA) communities. Previous research has highlighted the heterogeneous nature of SA ethnicity and the need to consider culture in SA patients’ self-management of T2D. We conducted a critical interpretative synthesis (CIS) which aimed to a) develop a new and comprehensive insight into the psychology which underpins SA patients’ T2D self-management behaviours and b) present a conceptual model to inform future T2D interventions. A systematic search of the literature retrieved 19 articles, including 536 participants. These were reviewed using established CIS procedures. Analysis identified seven constructs, from which an overarching synthesizing argument ‘Cultural Conflict’ was derived. Our findings suggest that patients reconstruct knowledge to manage their psychological, behavioural, and cultural conflicts, impacting decisional conflicts associated with T2D self-management and health professional advice (un)consciously. Those unable to resolve this conflict were more likely to default towards cultural identity, continue to align with cultural preferences rather than health professional guidance, and reduce engagement with self-management. Our synthesis and supporting model promote novel ideas for self-management of T2D care for SA patients. Specifically, health professionals should be trained and supported to explore and mitigate negative health beliefs to enable patients to manage social-cultural influences that impact their self-management behaviours. Keywords: type 2 diabetes; South Asian; culture; conflict; healthcare; qualitative; evidence synthesi

    A subset of non-small cell lung cancer patients treated with pemetrexed show 18f-fluorothymidine ‘flare’ on positron emission tomography

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    Thymidylate synthase (TS) remains a major target for cancer therapy. TS inhibition elicits increases in DNA salvage pathway activity, detected as a transient compensatory “flare” in 3′-deoxy-3′-[18F]fluorothymidine positron emission tomography (18F-FLT PET). We determined the magnitude of the 18F-FLT flare in non-small cell lung cancer (NSCLC) patients treated with the antifolate pemetrexed in relation to clinical outcome. Method: Twenty-one patients with advanced/metastatic non-small cell lung cancer (NSCLC) scheduled to receive palliative pemetrexed ± platinum-based chemotherapy underwent 18F-FLT PET at baseline and 4 h after initiating single-agent pemetrexed. Plasma deoxyuridine (dUrd) levels and thymidine kinase 1 (TK1) activity were measured before each scan. Patients were then treated with the combination therapy. The 18F-FLT PET variables were compared to RECIST 1.1 and overall survival (OS). Results: Nineteen patients had evaluable PET scans at both time points. A total of 32% (6/19) of patients showed 18F-FLT flares (>20% change in SUVmax-wsum). At the lesion level, only one patient had an FLT flare in all the lesions above (test–retest borders). The remaining had varied uptake. An 18F-FLT flare occurred in all lesions in 1 patient, while another patient had an 18F-FLT reduction in all lesions; 17 patients showed varied lesion uptake. All patients showed global TS inhibition reflected in plasma dUrd levels (p < 0.001) and 18F-FLT flares of TS-responsive normal tissues including small bowel and bone marrow (p = 0.004 each). Notably, 83% (5/6) of patients who exhibited 18F-FLT flares were also RECIST responders with a median OS of 31 m, unlike patients who did not exhibit 18F-FLT flares (15 m). Baseline plasma TK1 was prognostic of survival but its activity remained unchanged following treatment. Conclusions: The better radiological response and longer survival observed in patients with an 18F-FLT flare suggest the efficacy of the tracer as an indicator of the early therapeutic response to pemetrexed in NSCLC

    Deciphering interplay between Salmonella invasion effectors

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    Bacterial pathogens have evolved a specialized type III secretion system (T3SS) to translocate virulence effector proteins directly into eukaryotic target cells. Salmonellae deploy effectors that trigger localized actin reorganization to force their own entry into non-phagocytic host cells. Six effectors (SipC, SipA, SopE/2, SopB, SptP) can individually manipulate actin dynamics at the plasma membrane, which acts as a ‘signaling hub’ during Salmonella invasion. The extent of crosstalk between these spatially coincident effectors remains unknown. Here we describe trans and cis binary entry effector interplay (BENEFIT) screens that systematically examine functional associations between effectors following their delivery into the host cell. The results reveal extensive ordered synergistic and antagonistic relationships and their relative potency, and illuminate an unexpectedly sophisticated signaling network evolved through longstanding pathogen–host interaction
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