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Background: Thyroid hormone (TH) appears to have a reparative action on the postinfarcted myocardium. This novel action was recently tested in a pilot, randomized, double-blind, placebo-controlled trial (ThyRepair). The present study performed a post-hoc analysis of data from the ThyRepair study to provide further insights into the novel actions of TH on the human postischemic myocardium. Methods: Data from 41 patients participating in the ThyRepair study (n = 20 placebo and n = 21 LT3) were included in the analysis. LT3 treatment started after stenting and continued intravenously for 48 h. All patients had cardiac magnetic resonance (CMR) at hospital discharge; left ventricular (LV) ejection fraction (LVEF%), LV end-diastolic volume index (LVEDVi; mL/m2), LV end-systolic volume index (LVESVi; mL/m2), infarct volume (IV), left ventricular mass index (LVMi) as edema index, and microvascular obstruction (MVO) were assessed. Patients were divided into two groups based on the median value of the IV: patients with IV ≤ 20% of the LV (group A) and patients with IV > 20% (group B). CMR measurements at discharge are expressed as mean ± SD. Results: In group A, the placebo and T3-treated groups had similar LVEF% (56.8 ± 10.2 vs. 52.2 ± 10.5), LVEDVi (90.9 ± 19.8 vs. 92.8 ± 14.5), and LVESVi (40.8 ± 18.2 vs. 44.9 ± 14.1) at discharge. In group B, LVEDVi and LVESVi were 112 ± 23.8 and 68.3 ± 21.5 for placebo vs. 91.8 ± 18.6 and 49.0 ± 14.0 for the T3-treated group, respectively, p < 0.05. LVEF% was significantly increased in the T3-treated group vs. placebo, 47.3 ± 6.5 vs. 39.9 ± 8.7, p < 0.05. In group B, CMR LVMi was lower in T3-treated patients vs. placebo but did not reach statistical significance (p = 0.1). MVO was 1.95 ± 2.2 in placebo vs. 0.84 ± 0.9 in the LT3-treated group, p = 0.15. Conclusion: The present study suggests that acute LT3 treatment may exert more favorable effects on the recovery of cardiac function in patients with large infarct size. Furthermore, it signals a potential effect of LT3 on myocardial edema and microvascular obstruction. These novel findings merit further investigation in large trials.
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Função Ventricular Esquerda , Humanos , Masculino , Feminino , Método Duplo-Cego , Pessoa de Meia-Idade , Idoso , Função Ventricular Esquerda/efeitos dos fármacos , Infarto do Miocárdio/tratamento farmacológico , Infarto do Miocárdio/patologia , Hormônios Tireóideos/uso terapêutico , Volume Sistólico/efeitos dos fármacos , Projetos Piloto , Tri-Iodotironina/uso terapêutico , Tri-Iodotironina/administração & dosagem , Tri-Iodotironina/sangueRESUMO
This investigation explores the potential of electrochemical impedance spectroscopy (EIS) in evaluating graphene-based cementitious nanocomposites, focusing on their physical and structural properties, i.e., electrical resistivity, porosity, and fracture toughness. EIS was employed to study cement mixtures with varying graphene nanoplatelet (xGnP) concentrations (0.05-0.40% per dry cement weight), whereas flexural tests assessed fracture toughness and porosimetry analyses investigated the structural characteristics. The research demonstrated that the electrical resistivity initially decreased with increasing xGnP content, leveling off at higher concentrations. The inclusion of xGnPs correlated with an increase in the total porosity of the cement mixtures, which was indicated by both EIS and porosimetry measurements. Finally, a linear correlation emerged between fracture toughness and electrical resistivity, contributing also to underscore the use of EIS as a potent non-destructive tool for evaluating the physical and mechanical properties of conductive nano-reinforced cementitious nanocomposites.
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Natural Hydraulic Limes (NHL) are extensively used for the restoration of Monuments of Cultural Heritage, often combined with pozzolanic materials, such as natural pozzolans and metakaolin etc. In the present study, five (5) different cases of binary lime-based pastes composed of a specific type of NHL (NHL5) and metakaolin as pozzolanic addition were examined, that were reinforced with carbon nanostructures, namely graphene and carbon nanotubes. For the first time in restoration mortars, the incorporation of carbon nanostructures was investigated, aiming to produce materials with adequate piezoresistive response, so that they have the potential to be exploited for in situ structural health monitoring. The compressive strength, flexural strength, electrical resistance and piezoresistive response of the composite pastes was examined. The results showed that all modified carbon nanostructures lead to a significant reduction in electrical resistance. The pastes reinforced with 2D nanostructures (graphene family) displayed up to 30% increase in compressive strength and the pastes reinforced with 1D nanostructures (carbon nanotubes) displayed enhanced flexural strength (up to 100% increase). Piezoresistivity was attained for almost all investigated pastes, nevertheless the graphene oxide (GO) was considered as optimal reinforcement as the sensing ability of such pastes was found to be almost proportional to the applied compressive load level.
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Multi-wall carbon nanotubes (MWCNTs) exhibit exceptional mechanical and electrical properties and can be used to improve the mechanical and piezoelectric properties of cement-based materials. In the present study, the effect of different MWCNT concentrations as well as different types of surfactants and a superplasticizer were examined to reinforce, at the nanoscale, a white cement mortar typically used for the restoration of monuments of cultural heritage. It was shown that sodium dodecylbenzenesulfonate (SDBS) and Triton X-100 surfactants slightly decreased the white cement mortars' electrical resistivity (by an average of 10%), however, the mechanical properties were essentially decreased by an average of 60%. The most suitable dispersion agent for the MWCNTs proved to be the superplasticizer Ceresit CC198, and its optimal concentration was investigated for different MWCNT concentrations. Carboxylation of the MWCNT surface with nitric acid did not improve the mechanical performance of the white cement nanocomposites. The parametric experimental study showed that the optimum combination of 0.8 wt% of cement superplasticizer and 0.2 wt% of cement MWCNTs resulted in a 60% decrease in the electrical resistivity; additionally, the flexural and compressive strengths were both increased by approximately 25% and 10%, respectively.
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Background: Thyroid hormone has a differential action on healthy and ischemic heart. Triiodothyronine (T3) administration improved postischemic cardiac function while it limited apoptosis in experimentally induced ischemia. Thus, the present study investigated the potential effects of acute liothyronine (LT3) treatment in patients with anterior myocardial infarction. Methods: This study is a pilot, randomized, double-blind, placebo-controlled trial (ThyRepair study). We randomized 52 patients and analyzed data from 37 patients (n = 16 placebo and n = 21 LT3), per prespecified per protocol analysis. We excluded three patients who had died of cardiovascular causes (one in placebo and two in LT3 arm), four with small infarct size below a pre-specified threshold (in the placebo arm), and the rest, who lacked follow-up data. LT3 treatment started after stenting as an intravenous (i.v.) bolus injection of 0.8 µg/kg of LT3 followed by a constant infusion of 0.113 µg/kg/h i.v. for 48 hours. All patients had cardiac magnetic resonance (CMR) at hospital discharge and 6 months follow-up. The primary end point was CMR left ventricular (LV) ejection fraction (LVEF) and secondary endpoints were LV volumes, infarct volume (IV), and safety. Results: The CMR LVEF% at 6 months was 53.6 ± 9.5 for the LT3-treated group and 48.6 ± 11 for placebo, p = 0.15. Acute LT3 treatment resulted in a significantly lower LV end-diastolic volume index (92.2 ± 16.8 mL/m2 vs. 107.5 ± 22.2, p = 0.022) and LV systolic volume index (47.5 ± 13.9 mL/m2 vs. 61.3 ± 21.7, p = 0.024) at hospital discharge, but not at 6 months. There was no statistically significant difference in CMR IV at hospital discharge between the groups (p = 0.24). CMR IV tended to be lower in the LT3-treated group at 6 months (18.7 ± 9.5 vs. 25.9 ± 11.7, in placebo, p = 0.05). Serious, life-threatening events related to LT3 treatment were not observed. A tendency for an increased incidence of atrial fibrillation (AF) was found in the LT3 group during the first 48 hours (19% for T3 group vs. 5% for placebo, p = 0.13). Conclusion: This pilot randomized, placebo-controlled trial study suggests potential favorable effects (acute cardiac dilatation and 6-month IV) as well as potential concerns regarding a higher risk of AF after LT3 administration early after myocardial infarction, which should be tested in a larger scale study.
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Infarto do Miocárdio , Tri-Iodotironina , Angioplastia , Método Duplo-Cego , Humanos , Infarto do Miocárdio/tratamento farmacológico , Projetos Piloto , Resultado do Tratamento , Tri-Iodotironina/uso terapêuticoRESUMO
BACKGROUND: Previous studies suggest that late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) is associated with arrhythmic events in patients with nonischemic cardiomyopathy (NICM), while others have questioned the role of left ventricular ejection fraction (LVEF) as a sole predictor of future events. OBJECTIVES: To evaluate the role of LGE on CMR in identifying patients with NICM and reduced LVEF for whom a benefit from defibrillator implantation for primary prevention is not anticipated, thus they are mainly exposed to potential risks. METHODS: Major electronic databases were searched for studies reporting the incidence of appropriate device therapy (ADT), sudden cardiac death (SCD), and cardiac death based on the presence of LGE on CMR, among patients with NICM and reduced LVEF, implanted with a cardioverter defibrillator for primary prevention. RESULTS: Eleven studies (1652 patients, 947 with LGE) were included in the final analysis. LGE presence was strongly associated with ADT (logOR: 1.95, 95%CI: 1.21-2.69) and cardiac death (logOR: 0.91, 95%CI: 0.14-1.68), but not with SCD (logOR: 0.26, 95%CI: -1.09-1.6). Diagnostic accuracy analysis demonstrated that contrast enhancement is a sensitive marker of future ADT and cardiac death (93%, 95%CI: 85.8-96.7%; 82.9%, 95%CI: 70.6-90.7%; respectively), with moderate specificity ( 44%, 95%CI: 27.2-62.6%; 37.7%, 95%CI: 23.4-54.6%; respectively). CONCLUSION: LGE is a highly sensitive predictor of ADT and cardiac death in NICM patients implanted with a defibrillator for primary prevention. However, due to moderate specificity, derivation of a cutoff with adequate predictive values and probably a multifactorial approach are needed to improve discrimination of patients who will not benefit from ICDs.
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Cardiomiopatias , Desfibriladores Implantáveis , Disfunção Ventricular Esquerda , Cardiomiopatias/complicações , Cardiomiopatias/diagnóstico por imagem , Cardiomiopatias/terapia , Meios de Contraste , Morte Súbita Cardíaca/epidemiologia , Desfibriladores Implantáveis/efeitos adversos , Gadolínio , Humanos , Espectroscopia de Ressonância Magnética/efeitos adversos , Valor Preditivo dos Testes , Prevenção Primária , Prognóstico , Fatores de Risco , Volume Sistólico , Disfunção Ventricular Esquerda/complicações , Função Ventricular EsquerdaRESUMO
Carbon-based nanomaterials (CBNs), such as graphene and carbon nanotubes, display advanced physical and chemical properties, which has led to their widespread applications. One of these applications includes the incorporation of CBNs into cementitious materials in the form of aqueous dispersions. The main issue that arises in this context is that currently no established protocol exists as far as characterizing the dispersions. In the present article, an innovative method for quick evaluation and quantification of graphene oxide (GO) dispersions is proposed. The proposed method is electrical impedance spectroscopy (EIS) with an impedance sensor. The novelty lies on the exploitation of a small sensor for on-site (field) direct dielectric measurements with the application of alternating current. Five different concentrations of GO dispersions were studied by applying EIS and for various accumulated ultrasonic energies. The low GO concentration leads to high impedance values due to low formed current network. Two opposing mechanisms were revealed during the accumulation of ultrasonic energy, that are taking place simultaneously: breakage of the agglomerates that facilitates the flow of the electric current due to the formation of a better dispersed network, nevertheless the surface hydrophilic structure of the GO is damaged with the high accumulated ultrasonic energy. The dielectric measurements were exploited to express an appropriate quantitative 'quality index' to facilitate with the dispersion control of the nanostructures. An intermediate concentration of GO is suggested (about 0.15 wt% of the binder materials) to be optimal for the specific engineering application, ultrasonicated at approximately 30 to 65 kJ. The investigated methodology is highly novel and displays a high potential to be applied in-field applications where CBNs must be incorporated in building materials.
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A 42-year-old man presented with fever, sore throat, rash and painful right knee swelling, preceded by self-medication with oral steroids. Blood and knee cultures yielded group A Streptococcus After 2 weeks of intravenous antibiotics and two arthroscopic knee debridements, he continued to experience spiking fevers, and electrocardiographic changes developed. We postulate that the patient suffered from the first presentation of acute rheumatic fever, following an invasive group A bacteraemic streptococcal infection. The possible role of cardiac magnetic resonance imaging in the diagnosis of rheumatic carditis is discussed.
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Miocardite , Febre Reumática , Infecções Estreptocócicas , Adulto , Humanos , Imageamento por Ressonância Magnética , Masculino , Miocardite/diagnóstico por imagem , Febre Reumática/complicações , Infecções Estreptocócicas/diagnóstico , Infecções Estreptocócicas/diagnóstico por imagem , Streptococcus pyogenesAssuntos
Aortite/diagnóstico por imagem , Imunoglobulina G , Miocardite/diagnóstico por imagem , Taquicardia Ventricular/diagnóstico por imagem , Aortite/sangue , Aortite/complicações , Humanos , Imunoglobulina G/sangue , Masculino , Pessoa de Meia-Idade , Miocardite/sangue , Miocardite/complicações , Recidiva , Taquicardia Ventricular/sangue , Taquicardia Ventricular/complicaçõesRESUMO
Atherosclerosis affects the majority of adult individuals in industrialized nations and it is beginning to affect even traditionally spared populations. The classic view has been that the precipitating events are intraluminal. However, good evidence supports the possibility that at least part of the atherosclerosis burden may be the consequence of extra-luminal noxious stimuli. Additionally, the epidemic of obesity, insulin resistance and diabetes mellitus has generated a strong interest in the potential role of visceral adipose tissue as an extra-luminal promoter of atherosclerosis. The epicardial space is filled with adipose tissue with an embryological origin similar to that of abdominal visceral fat. Both fats are highly inflamed in obese patients, patients with the metabolic syndrome and in those with established coronary artery disease. Additionally they are capable of secreting large quantities of pro-inflammatory cytokines and free fatty acids but also anti-inflammatory adipokines like adiponectin. In this manuscript we review the current evidence supporting the role of epicardial adipose tissue in the development of atherosclerosis and its complications.
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Aterosclerose/metabolismo , Doença da Artéria Coronariana/complicações , Gordura Intra-Abdominal/metabolismo , Obesidade/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Early detection of vascular inflammation would allow deployment of targeted strategies for the prevention or treatment of multiple disease states. Because vascular inflammation is not detectable with commonly used imaging modalities, we hypothesized that phenotypic changes in perivascular adipose tissue (PVAT) induced by vascular inflammation could be quantified using a new computerized tomography (CT) angiography methodology. We show that inflamed human vessels release cytokines that prevent lipid accumulation in PVAT-derived preadipocytes in vitro, ex vivo, and in vivo. We developed a three-dimensional PVAT analysis method and studied CT images of human adipose tissue explants from 453 patients undergoing cardiac surgery, relating the ex vivo images with in vivo CT scan information on the biology of the explants. We developed an imaging metric, the CT fat attenuation index (FAI), that describes adipocyte lipid content and size. The FAI has excellent sensitivity and specificity for detecting tissue inflammation as assessed by tissue uptake of 18F-fluorodeoxyglucose in positron emission tomography. In a validation cohort of 273 subjects, the FAI gradient around human coronary arteries identified early subclinical coronary artery disease in vivo, as well as detected dynamic changes of PVAT in response to variations of vascular inflammation, and inflamed, vulnerable atherosclerotic plaques during acute coronary syndromes. Our study revealed that human vessels exert paracrine effects on the surrounding PVAT, affecting local intracellular lipid accumulation in preadipocytes, which can be monitored using a CT imaging approach. This methodology can be implemented in clinical practice to noninvasively detect plaque instability in the human coronary vasculature.
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Tecido Adiposo/irrigação sanguínea , Tecido Adiposo/patologia , Vasos Coronários/patologia , Imageamento Tridimensional , Inflamação/patologia , Adipócitos/patologia , Adipogenia , Diferenciação Celular , Proliferação de Células , Tamanho Celular , Vasos Coronários/diagnóstico por imagem , Citocinas/metabolismo , Humanos , Inflamação/diagnóstico por imagem , Lipídeos/química , Fenótipo , Placa Aterosclerótica/diagnóstico por imagem , Placa Aterosclerótica/patologia , Tomografia Computadorizada por Raios XAssuntos
Insuficiência Cardíaca/complicações , Vasculite por IgA/complicações , Miocardite/etiologia , Miocárdio/patologia , Doença Aguda , Biópsia , Humanos , Vasculite por IgA/diagnóstico , Imagem Cinética por Ressonância Magnética , Masculino , Miocardite/diagnóstico , Pele/patologia , Adulto JovemRESUMO
Cardiovascular disease is highly prevalent and it is associated with high morbidity and mortality rates in patients with chronic kidney disease (CKD). The implementation of various imaging modalities may help to risk stratify these patients with a potential ease on the burden of complications and the rising costs of care. In this article we review some of the modern imaging techniques to diagnose cardiac disease in patients affected by CKD.
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Doenças Cardiovasculares/diagnóstico por imagem , Doenças Cardiovasculares/etiologia , Insuficiência Renal Crônica/complicações , Técnicas de Imagem Cardíaca , Humanos , Insuficiência Renal Crônica/diagnóstico por imagemAssuntos
Coartação Aórtica/complicações , Valva Aórtica/anormalidades , Cardiopatias Congênitas/complicações , Doenças das Valvas Cardíacas/complicações , Adulto , Coartação Aórtica/diagnóstico por imagem , Coartação Aórtica/fisiopatologia , Valva Aórtica/diagnóstico por imagem , Valva Aórtica/fisiopatologia , Doença da Válvula Aórtica Bicúspide , Ecocardiografia , Feminino , Cardiopatias Congênitas/diagnóstico por imagem , Cardiopatias Congênitas/fisiopatologia , Doenças das Valvas Cardíacas/diagnóstico por imagem , Doenças das Valvas Cardíacas/fisiopatologia , Humanos , Angiografia por Ressonância Magnética , Volume Sistólico , Fatores de Tempo , Função Ventricular EsquerdaAssuntos
Cistos/diagnóstico , Equinococose/diagnóstico , Echinococcus , Imagem Multimodal/métodos , Pericárdio/patologia , Animais , Cistos/complicações , Equinococose/complicações , Echinococcus/isolamento & purificação , Ecocardiografia/métodos , Feminino , Humanos , Imagem Cinética por Ressonância Magnética/métodos , Pessoa de Meia-Idade , Tomografia Computadorizada por Raios X/métodosRESUMO
Sirtuins (SIRTs) are a class of nicotine adenine dinucleotide (NAD+)-dependent proteins which participate in numerous molecular pathways involved in various age-related human diseases, such as type II diabetes, cardiovascular (CV) diseases and cancer. They have a major role in apoptosis, inflammation, oxidative stress and metabolism regulation, traits that have a great impact on CV physiology and pathology. Their unique profile of NAD+ energy dependency makes them an appealing target for human intervention in cellular and metabolic processes. This review focuses on the recent advances of SIRTs research aiming to shed light on the emerging roles of SIRTs in the pathophysiology of CV and metabolic diseases.