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1.
bioRxiv ; 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38915649

RESUMO

BACKGROUND: ATP-citrate lyase (ACLY) converts citrate into acetyl-CoA and oxaloacetate in the cytosol. It plays a prominent role in lipogenesis and fat accumulation coupled to excess glucose, and its inhibition is approved for treating hyperlipidemia. In RNAseq analysis of human failing myocardium, we found ACLY gene expression is reduced; however the impact this might have on cardiac function and/or metabolism has not been previously studied. As new ACLY inhibitors are in development for cancer and other disorders, such understanding has added importance. METHODS: Cardiomyocytes, ex-vivo beating hearts, and in vivo hearts with ACLY inhibited by selective pharmacologic (BMS303141, ACLYi) or genetic suppression, were studied. Regulation of ACLY gene/protein expression, and effects of ACLYi on function, cytotoxicity, tricarboxylic acid (TCA)-cycle metabolism, and redox and NAD+/NADH balance were assessed. Mice with cardiac ACLY knockdown induced by AAV9-acly-shRNA or cardiomyocyte tamoxifen-inducible Acly knockdown were studied. RESULTS: Acly gene expression was reduced more in obese patients with heart failure and preserved EF (HFpEF) than HF with reduced EF. In vivo pressure-overload and in vitro hormonal stress increased ACLY protein expression, whereas it declined upon fatty-acid exposure. Acute ACLYi (1-hr) dose-dependently induced cytotoxicity in adult and neonatal cardiomyocytes, and caused substantial reduction of systolic and diastolic function in myocytes and ex-vivo beating hearts. In the latter, ATP/ADP ratio also fell and lactate increased. U13C-glucose tracing revealed an ACLYdependent TCA-bypass circuit in myocytes, where citrate generated in mitochondria is transported to the cytosol, metabolized by ACLY and then converted to malate to re-enter mitochondria,bypassing several NADH-generating steps. ACLYi lowered NAD+/NADH ratio and restoring this balance ameliorated cardiomyocyte toxicity. Oxidative stress was undetected with ACLYi. Adult hearts following 8-weeks of reduced cardiac and/or cardiomyocyte ACLY downregulation exhibited ventricular dilation and reduced function that was prevented by NAD augmentation. Cardiac dysfunction from ACLY knockdown was worse in hearts subjected to sustained pressureoverload, supporting a role in stress responses. CONCLUSIONS: ACLY supports normal cardiac function through maintenance of the NAD+/NADH balance and is upregulated by hemodynamic and hormonal stress, but depressed by lipid excess. ACLY levels are most reduced in human HFpEF with obesity potentially worsening cardio-metabolic reserve.

2.
JCI Insight ; 6(13)2021 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-34061779

RESUMO

The emergence of the novel SARS coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), has resulted in an unprecedented pandemic that has been accompanied by a global health crisis. Although the lungs are the main organs involved in COVID-19, systemic disease with a wide range of clinical manifestations also develops in patients infected with SARS-CoV-2. One of the major systems affected by this virus is the cardiovascular system. The presence of preexisting cardiovascular disease increases mortality in patients with COVID-19, and cardiovascular injuries, including myocarditis, cardiac rhythm abnormalities, endothelial cell injury, thrombotic events, and myocardial interstitial fibrosis, are observed in some patients with COVID-19. The underlying pathophysiology of COVID-19-associated cardiovascular complications is not fully understood, although direct viral infection of myocardium and cytokine storm have been suggested as possible mechanisms of myocarditis. In this Review, we summarize available data on SARS-CoV-2-related cardiac damage and discuss potential mechanisms of cardiovascular implications of this rapidly spreading virus.


Assuntos
COVID-19/complicações , Doenças Cardiovasculares/etiologia , Arritmias Cardíacas/diagnóstico , Arritmias Cardíacas/etiologia , Doenças Cardiovasculares/diagnóstico , Fibrose/diagnóstico , Fibrose/etiologia , Humanos , Miocardite/diagnóstico , Miocardite/etiologia , Disautonomias Primárias/diagnóstico , Disautonomias Primárias/etiologia , Trombose/diagnóstico , Trombose/etiologia , Vasculite/diagnóstico , Vasculite/etiologia , Tratamento Farmacológico da COVID-19
3.
BMJ Open ; 9(1): e023625, 2019 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-30782711

RESUMO

OBJECTIVES: To provide a comprehensive systematic overview of current evidence from pooled analyses/meta-analyses and systematic reviews (PMASRs) pertaining to dairy consumption and incident cancer and/or all-cause or cancer-specific mortality. DESIGN: Overview of reviews. SETTING: Community setting. PARTICIPANTS: The unit of analysis is PMASRs. A total of 42 PMASRs was included in this overview of reviews. INTERVENTIONS/EXPOSURES: Any dairy product consumption (eg, milk, yogurt, etc). PRIMARY AND SECONDARY OUTCOMES MEASURES: Primary outcome measure is development of any type of cancer. Secondary outcome measures are all-cause mortality and cancer-specific mortality. RESULTS: From 9693 citations identified, we included 42 PMASRs (52 study reports) published between 1991 and 2017. Thirty-one (74%) of these was pooled analyses/meta analyses, and only 11 (26%) were systematic reviews and meta-analyses. There was a wide variability in the type of study designs included within the other PMASRs, thus contributing to variable and, in instances, divergent estimates of cancer risk for several cancer subtypes. For example, only one systematic review and meta-analysis exclusively included prospective study designs. Most PMASRs were of low to moderate quality based on the Assessing the Methodological Quality of Systematic Reviews (AMSTAR) scores. The median AMSTAR score was 5 (IQR 2-7). Our overview identified conflicting evidence from PMASRs on association between dairy consumption and incident cancers or mortality. Heterogeneity in summary estimates reflected the inclusion of variable study designs and overall low methodological quality of individual PMASRs. CONCLUSIONS: The association between dairy consumption and cancer risk has been explored in PMASRs with a variety of study designs and of low to moderate quality. To fully characterise valid associations between dairy consumption and risk of cancer and/or mortality rigorously conducted, PMASRs including only high-quality prospective study designs are required. TRIAL REGISTRATION NUMBER: CRD42017078463.


Assuntos
Laticínios/efeitos adversos , Neoplasias/etiologia , Causalidade , Humanos , Metanálise como Assunto , Fatores de Risco , Revisões Sistemáticas como Assunto
4.
Leadersh Health Serv (Bradf Engl) ; 31(1): 77-97, 2018 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-29412095

RESUMO

Purpose Strong leadership has been shown to foster change, including loyalty, improved performance and decreased error rates, but there is a dearth of evidence on effectiveness of leadership development programs. To ensure a return on the huge investments made, evidence-based approaches are needed to assess the impact of leadership on health-care establishments. As a part of a pan-Canadian initiative to design an effective evaluative instrument, the purpose of this paper was to identify and summarize evidence on health-care outcomes/return on investment (ROI) indicators and metrics associated with leadership quality, leadership development programs and existing evaluative instruments. Design/methodology/approach The authors performed a scoping review using the Arksey and O'Malley framework, searching eight databases from 2006 through June 2016. Findings Of 11,868 citations screened, the authors included 223 studies reporting on health-care outcomes/ROI indicators and metrics associated with leadership quality (73 studies), leadership development programs (138 studies) and existing evaluative instruments (12 studies). The extracted ROI indicators and metrics have been summarized in detail. Originality/value This review provides a snapshot in time of the current evidence on ROI indicators and metrics associated with leadership. Summarized ROI indicators and metrics can be used to design an effective evaluative instrument to assess the impact of leadership on health-care organizations.


Assuntos
Pessoal Administrativo/educação , Atenção à Saúde/organização & administração , Liderança , Modelos Educacionais , Desenvolvimento de Pessoal , Humanos , Aprendizagem
5.
Curr Protein Pept Sci ; 18(12): 1273-1287, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28595527

RESUMO

Creatine, a very popular supplement among athletic populations, is of growing interest for clinical applications. Since over 90% of creatine is stored in skeletal muscle, the effect of creatine supplementation on muscle metabolism is a widely studied area. While numerous studies over the past few decades have shown that creatine supplementation has many favorable effects on skeletal muscle physiology and metabolism, including enhancing muscle mass (growth/hypertrophy); the underlying mechanisms are poorly understood. This report reviews studies addressing the mechanisms of action of creatine supplementation on skeletal muscle growth/hypertrophy. Early research proposed that the osmotic effect of creatine supplementation serves as a cellular stressor (osmosensing) that acts as an anabolic stimulus for protein synthesis signal pathways. Other reports indicated that creatine directly affects muscle protein synthesis via modulations of components in the mammalian target of rapamycin (mTOR) pathway. Creatine may also directly affect the myogenic process (formation of muscle tissue), by altering secretions of myokines, such as myostatin and insulin-like growth factor-1, and expressions of myogenic regulatory factors, resulting in enhanced satellite cells mitotic activities and differentiation into myofiber. Overall, there is still no clear understanding of the mechanisms of action regarding how creatine affects muscle mass/growth, but current evidence suggests it may exert its effects through multiple approaches, with converging impacts on protein synthesis and myogenesis.


Assuntos
Creatina/administração & dosagem , Suplementos Nutricionais , Desenvolvimento Muscular/efeitos dos fármacos , Fatores de Regulação Miogênica/genética , Biossíntese de Proteínas/efeitos dos fármacos , Animais , Diferenciação Celular , Regulação da Expressão Gênica , Humanos , Fator de Crescimento Insulin-Like I/genética , Fator de Crescimento Insulin-Like I/metabolismo , Células Musculares/citologia , Células Musculares/metabolismo , Desenvolvimento Muscular/genética , Músculo Esquelético/citologia , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/metabolismo , Fatores de Regulação Miogênica/agonistas , Fatores de Regulação Miogênica/metabolismo , Miostatina/genética , Miostatina/metabolismo , Biossíntese de Proteínas/genética , Células Satélites de Músculo Esquelético/citologia , Células Satélites de Músculo Esquelético/metabolismo , Transdução de Sinais , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo
6.
Can J Cardiol ; 33(12): 1611-1623, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-29173601

RESUMO

BACKGROUND: Randomized controlled trials (RCTs) on bone marrow stem cell (BMSC) therapy in ST-elevation myocardial infarction (STEMI) patients have reported conflicting results. Our main objective was to critically appraise and meta-analyze best-available evidence on efficacy and safety of intracoronary administration of autologous BMSC therapy in STEMI patients after primary percutaneous coronary intervention. METHODS: We conducted a search of MEDLINE, PubMed, EMBASE, CENTRAL, Global Health, CINAHL, and conference proceedings in February 2017. Our primary outcome was all-cause mortality. Secondary and safety outcomes included cardiac death, heart failure, arrhythmias, repeat myocardial infarction, or target vessel revascularizations; or improved health-related quality of life, left ventricular ejection fraction, or infarct size. Summary relative and absolute risks were obtained using random effects models. We also evaluated the strength of evidence. RESULTS: A comprehensive database search identified 42 RCTs (3365 STEMI patients). BMSC therapy did not significantly decrease mortality (risk ratio, 0.71; 95% confidence interval, 0.45-1.11; I2, 0%; absolute risk reduction, 0.1%; 95% confidence interval, -0.71 to 0.91; 40 trials; 3289 participants; I2, 0%; low strength of evidence). BMSC therapy had no effect on secondary or adverse outcomes. Trial sequential analysis for all-cause mortality showed no evidence of a clinically important difference, with a very low probability that future studies can change the current conclusion. CONCLUSIONS: On the basis of evidence from 42 RCTs published in the past 15 years, we provide conclusive evidence for a lack of beneficial effect for autologous BMSC therapy in patients with STEMI.


Assuntos
Células da Medula Óssea/citologia , Infarto do Miocárdio com Supradesnível do Segmento ST/terapia , Transplante de Células-Tronco/métodos , Humanos , Transplante Autólogo
7.
J Radiol Case Rep ; 2(1): 16-9, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-22470583

RESUMO

A 14 year old male was referred to a CT scan at our hospital for evaluation of headache. The patient was a known case of cervical soft tissue primitive neuroectodermal tumor (PNET) who has undergone surgery and radiotherapy 4 years ago. CT scan showed a large solitary extra axial, epidural lesion in the right parietal region, with mass effect and bony involvement. Subsequently, surgery was performed and the resultant biopsy was neuroepithelioma. After diagnosis the patient has undergone chemotherapy and radiotherapy. He remained symptom free, and also follow up CT scans of the brain, chest, and abdomen were normal after two years post surgery. This is the first reported case of epidural metastasis of a head and neck (peripheral) PNET.

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