1,502 research outputs found

    Identification of genomic biomarkers for anthracycline-induced cardiotoxicity in human iPSC-derived cardiomyocytes: an in vitro repeated exposure toxicity approach for safety assessment.

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    The currently available techniques for the safety evaluation of candidate drugs are usually cost-intensive and time-consuming and are often insufficient to predict human relevant cardiotoxicity. The purpose of this study was to develop an in vitro repeated exposure toxicity methodology allowing the identification of predictive genomics biomarkers of functional relevance for drug-induced cardiotoxicity in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). The hiPSC-CMs were incubated with 156 nM doxorubicin, which is a well-characterized cardiotoxicant, for 2 or 6 days followed by washout of the test compound and further incubation in compound-free culture medium until day 14 after the onset of exposure. An xCELLigence Real-Time Cell Analyser was used to monitor doxorubicin-induced cytotoxicity while also monitoring functional alterations of cardiomyocytes by counting of the beating frequency of cardiomyocytes. Unlike single exposure, repeated doxorubicin exposure resulted in long-term arrhythmic beating in hiPSC-CMs accompanied by significant cytotoxicity. Global gene expression changes were studied using microarrays and bioinformatics tools. Analysis of the transcriptomic data revealed early expression signatures of genes involved in formation of sarcomeric structures, regulation of ion homeostasis and induction of apoptosis. Eighty-four significantly deregulated genes related to cardiac functions, stress and apoptosis were validated using real-time PCR. The expression of the 84 genes was further studied by real-time PCR in hiPSC-CMs incubated with daunorubicin and mitoxantrone, further anthracycline family members that are also known to induce cardiotoxicity. A panel of 35 genes was deregulated by all three anthracycline family members and can therefore be expected to predict the cardiotoxicity of compounds acting by similar mechanisms as doxorubicin, daunorubicin or mitoxantrone. The identified gene panel can be applied in the safety assessment of novel drug candidates as well as available therapeutics to identify compounds that may cause cardiotoxicity

    Exogenous WNT5A and WNT11 proteins rescue CITED2 dysfunction in mouse embryonic stem cells and zebrafish morphants

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    Mutations and inadequate methylation profiles of CITED2 are associated with human congenital heart disease (CHD). In mouse, Cited2 is necessary for embryogenesis, particularly for heart development, and its depletion in embryonic stem cells (ESC) impairs cardiac differentiation. We have now determined that Cited2 depletion in ESC affects the expression of transcription factors and cardiopoietic genes involved in early mesoderm and cardiac specification. Interestingly, the supplementation of the secretome prepared from ESC overexpressing CITED2, during the onset of differentiation, rescued the cardiogenic defects of Cited2-depleted ESC. In addition, we demonstrate that the proteins WNT5A and WNT11 held the potential for rescue. We also validated the zebrafish as a model to investigate cited2 function during development. Indeed, the microinjection of morpholinos targeting cited2 transcripts caused developmental defects recapitulating those of mice knockout models, including the increased propensity for cardiac defects and severe death rate. Importantly, the co-injection of anti-cited2 morpholinos with either CITED2 or WNT5A and WNT11 recombinant proteins corrected the developmental defects of Cited2-morphants. This study argues that defects caused by the dysfunction of Cited2 at early stages of development, including heart anomalies, may be remediable by supplementation of exogenous molecules, offering the opportunity to develop novel therapeutic strategies aiming to prevent CHD.Agência financiadora: Fundação para a Ciência e a Tecnologia (FCT) Comissão de Coordenação e Desenvolvimento Regional do Algarve (CCDR Algarve) ALG-01-0145-FEDER-28044; DFG 568/17-2 Algarve Biomedical Center (ABC) Municipio de Louléinfo:eu-repo/semantics/publishedVersio

    Prognostic factors for outcomes after whole-brain irradiation of brain metastases from relatively radioresistant tumors: a retrospective analysis

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    <p>Abstract</p> <p>Background</p> <p>This study investigated potential prognostic factors in patients treated with whole-brain irradiation (WBI) alone for brain metastases from relatively radioresistant tumors such as malignant melanoma, renal cell carcinoma, and colorectal cancer. Additionally, a potential benefit from escalating the radiation dose was investigated.</p> <p>Methods</p> <p>Data from 220 patients were retrospectively analyzed for overall survival and local control. Nine potential prognostic factors were evaluated: tumor type, WBI schedule, age, gender, Karnofsky performance score, number of brain metastases, extracerebral metastases, interval from diagnosis of cancer to WBI, and recursive partitioning analysis (RPA) class.</p> <p>Results</p> <p>Survival rates at 6 and 12 months were 32% and 19%, respectively. In the multivariate analysis, WBI doses >30 Gy (p = 0.038), KPS ≥70 (p < 0.001), only 1-3 brain metastases (p = 0.007), no extracerebral metastases (p < 0.001), and RPA class 1 (p < 0.001) were associated with improved survival. Local control rates at 6 and 12 months were 37% and 15%, respectively. In the multivariate analyses, KPS ≥70 (p < 0.001), only 1-3 brain metastases (p < 0.001), and RPA class 1 (p < 0.001) were associated with improved local control. In RPA class 3 patients, survival rates at 6 months were 10% (35 of 39 patients) after 10 × 3 Gy and 9% (2 of 23 patients) after greater doses, respectively (p = 0.98).</p> <p>Conclusions</p> <p>Improved outcomes were associated with WBI doses >30 Gy, better performance status, fewer brain metastases, lack of extracerebral metastases, and lower RPA class. Patients receiving WBI alone appear to benefit from WBI doses >30 Gy. However, such a benefit is limited to RPA class 1 or 2 patients.</p

    Role of transesophageal echocardiography in the assessment and therapeutic management of patients with acute ischemic cerebral events before the age of 65

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    INTRODUCTION: Ischemic stroke is the leading cause of mortality in Portugal, with around 30 to 50 % of cases being of cardioembolic etiology. Transesophageal echocardiography (TEE) has assumed growing importance in the detection of cardiac sources of embolism. However, there is controversy regarding the implications of TEE findings for the therapeutic approach to patients with ischemic stroke. OBJECTIVES: To analyze TEE findings in the diagnostic work-up of patients with ischemic cerebral events and to determine their influence on therapeutic strategy. METHODS: We retrospectively studied patients with stroke or transient ischemic attack (TIA) before the age of 65, of no apparent cause after carotid ultrasound, electrocardiogram and transthoracic echocardiography, who underwent TEE between 1992 and 2009. The following diagnoses on TEE were considered as potential embolic sources: atrial septal defect; patent foramen ovale (PFO); atrial septal aneurysm (ASA); vegetations; tumors; intracavitary thrombi; and aortic plaques >2mm (ascending aorta and arch). RESULTS: We analyzed 294 patients, mean age 45 years, 56.8 % men. TEE revealed a potential cardioembolic source in 36.7 % of the patients, PFO and ASA being the most frequent. Throughout the period considered, there was an increase in the number of exams performed, as well as in diagnoses, mainly PFO and ASA. Comparison of patients with and without a diagnosis on TEE showed that the former were older and were more often prescribed oral anticoagulation. By multivariate analysis, the presence of a positive TEE finding was shown to be an independent predictor of treatment with oral anticoagulation (OR=2.48; CI 95%: 1.42-4.34; p=0.001). CONCLUSION: In the population under analysis, TEE was useful in identifying potential cardioembolic sources and infl uenced the therapeutic strategy

    The social and healthcare professional support drawn upon by women antenatally during the COVID-19 pandemic: A recurrent, cross-sectional, thematic analysis

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    Objective: To explore antenatal experiences of social and healthcare professional support during different phases of social distancing restriction implementation in the UK. Design: Semi-structured interviews were conducted via telephone or video-conferencing software between 13 July 2020 – 2 September 2020. Interviews were transcribed and a recurrent, cross-sectional, thematic analysis was conducted. Participants: Twelve antenatal women were interviewed during UK social distancing restrictions (Timepoint 1; T1) and a separate sample of twelve women were interviewed in the initial easing of these restrictions (Timepoint 2; T2). Findings: T1 themes were: ‘Maternity care as non-essential’ and ‘Pregnancy is cancelled’. T2 themes were: ‘Technology is a polarised tool’ and ‘Clinically vulnerable, or not clinically vulnerable? That is the question’. Key conclusions: At T1, anxieties were ascribed to the exclusion of partners from routine care, and to perceived insensitivity and aggression from the public. For T2, insufficient Governmental transparency led to disillusionment, confusion, and anger. Covert workplace discrimination also caused distress at T2. Across timepoints: deteriorated mental wellbeing was attributed to depleted opportunities to interact socially and scaled back maternity care. Implications for practice: Recommendations are made to: protect maternal autonomy; improve quality of mental health and routine care signposting; prioritise parental community support in the re-opening of ‘non-essential’ services; prioritise the option for face-to-face appointments when safe and legal; and protecting the rights of working mothers

    Validation of control of allergic rhinitis and asthma test for children (CARATKids)--a prospective multicenter study

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    BACKGROUND: Control of Allergic Rhinitis and Asthma Test for Children (CARATKids) is the first questionnaire that assesses simultaneously allergic rhinitis and asthma control in children. It was recently developed, but redundancy of questions and its psychometric properties were not assessed. This study aimed to (i) establish the final version of the CARATKids questionnaire and (ii) evaluate its reliability, responsiveness, cross-sectional validity, and longitudinal validity. METHODS: A prospective observational study was conducted in 11 Portuguese centers. During two visits separated by 6 wk, CARATKids, visual analog scale scales and childhood asthma control test were completed, and participant's asthma and rhinitis were evaluated by his/her physician without knowing the questionnaires' results. Data-driven item reduction was conducted, and internal consistency, responsiveness analysis, and associations with external measures of disease status were assessed. RESULTS: Of the 113 children included, 101 completed both visits. After item reduction, the final version of the questionnaire has 13 items, eight to be answered by the child and five by the caregiver. Its Cronbach's alpha was 0.80, the Guyatt's responsiveness index was -1.51, and a significant (p < 0.001) within-patient change of CARATKids score in clinical unstable patients was observed. Regarding cross-sectional validity, correlation coefficients of CARATKids with the external measures of control were between 0.45 and -0.69 and met the a priori predictions. In the longitudinal validity assessment, the correlation coefficients between the score changes of CARATKids and those of external measures of control ranged from 0.34 to 0.46

    The antenatal psychological experiences of women during two phases of the COVID-19 pandemic: A recurrent, cross-sectional, thematic analysis

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    Initial COVID-19-related social distancing restrictions, imposed in the UK in March 2020, and the subsequent lifting of restrictions in May 2020 caused antenatal disruption and stress which exceeded expected vulnerabilities associated with this lifecourse transition. The current study aimed to explore the antenatal psychological experiences of women during different phases of pandemic-related lockdown restrictions in the UK. Semi-structured interviews were held with 24 women about their antenatal experiences: twelve were interviewed after the initial lockdown restrictions (Timepoint 1; T1), and a separate twelve women were interviewed after the subsequent lifting of those restrictions (Timepoint 2; T2). Interviews were transcribed and a recurrent, cross-sectional thematic analysis was conducted. Two themes were identified for each timepoint, and each theme contained sub-themes. T1 themes were: ‘A Mindful Pregnancy’ and ‘It’s a Grieving Process’, and T2 themes were: ‘Coping with Lockdown Restrictions’ and ‘Robbed of Our Pregnancy’. COVID-19 related social distancing restrictions had an adverse effect on women’s mental health during the antenatal period. Feeling trapped, anxious, and abandoned were common at both timepoints. Actively encouraging conversations about mental wellbeing during routine care and adopting a prevention opposed to cure attitude toward implementing additional support provisions may serve to improve antenatal psychological wellbeing during health crises
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