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1.
Tempo psicanál ; 54(2): 46-60, jul.-dez. 2022.
Artículo en Portugués | LILACS-Express | LILACS, Index Psicología - Revistas | ID: biblio-1450540

RESUMEN

Cinema é comunicação? Ou apenas em certas circunstâncias? E, nessas circunstâncias, estaríamos diante de que natureza de evento? Um "acontecimento comunicacional"? A partir do detalhamento do conceito de "corpo cinemático" de Shaviro, da "intensidade das imagens" de Massumi e da fenomenologia de Whitehead faremos um Estudo de Caso: o evento proporcionado pela exibição do filme How to Get Ahead in Advertising [Como Fazer Carreira em Publicidade] (1989) para uma classe de graduação do curso de Publicidade e Propaganda. Efeitos ideológicos por meios não ideológicos (afetos, intensidades e sentimentos) seriam os resultantes dos acontecimentos comunicacionais?


Could cinema provide communication? Or only in certain circumstances? And under these circumstances, what kind of event would we be facing? A "communicational event"? From the details of Shaviro's concept of "cinematic body", Massumi's "image intensity" and Whitehead's phenomenology, we will make a case study: the event provided by the exhibition of the film How to Get Ahead in Advertising (1989) to a graduate class of the Advertising and Propaganda course. Are ideological effects through non-ideological means (affections, intensities, and feelings) the ones resulting from communicational events?


¿El cine es comunicación? ¿O solo en determinadas circunstancias? Y en estas circunstancias, ¿a qué tipo de evento nos enfrentaríamos? ¿Un "evento comunicacional"? A partir de los detalles del concepto de "cuerpo cinematográfico" de Shaviro, la "intensidad de la imagen" de Massumi y la fenomenología de Whitehead, haremos un estudio de caso: el evento que brinda la exhibición de la película How to Get Ahead in Advertising [Cómo Triunfar en Publicidad] (1989) a un graduado clase del curso de Publicidad y Propaganda. ¿Los efectos ideológicos a través de medios no ideológicos (afecciones, intensidades y sentimientos) son el resultado de eventos comunicacionales?

2.
Eur Heart J Cardiovasc Imaging ; 23(9): 1248-1259, 2022 08 22.
Artículo en Inglés | MEDLINE | ID: mdl-35640278

RESUMEN

AIMS: Epicardial adipose tissue (EAT) volume and attenuation on computed tomography (CT) have been associated with atrial fibrillation. Beyond these conventional CT measures, radiomics allows extraction of high-dimensional data and deep quantitative adipose tissue phenotyping, which may capture its underlying biology. We aimed to explore the EAT proteomic and CT-radiomic signatures associated with impaired left atrial (LA) remodelling and post-operative atrial fibrillation (POAF). METHODS AND RESULTS: We prospectively included 132 patients with severe aortic stenosis with no prior atrial fibrillation referred for aortic valve replacement. Pre-operative non-contrast CT images were obtained for extraction of EAT volume and other radiomic features describing EAT texture. The LA function was assessed by 2D-speckle-tracking echocardiography peak atrial longitudinal strain and peak atrial contraction strain. The EAT biopsies were performed during surgery for proteomic analysis by sequential windowed acquisition of all theoretical fragment ion mass spectra (SWATH-MS). The POAF incidence was monitored from surgery until discharge. Impaired LA function and incident POAF were associated with EAT up-regulation of inflammatory and thrombotic proteins, and down-regulation of cardioprotective proteins with anti-inflammatory and anti-lipotoxic properties. The EAT volume was independently associated with LA enlargement, impaired function, and POAF risk. On CT images, EAT texture of patients with POAF was heterogeneous and exhibited higher maximum grey-level values than sinus rhythm patients, which correlated with up-regulation of inflammatory and down-regulation of lipid droplet-formation EAT proteins. The CT radiomics of EAT provided an area under the curve of 0.80 (95% confidence interval: 0.68-0.92) for discrimination between patients with POAF and sinus rhythm. CONCLUSION: Pre-operative CT-radiomic profile of EAT detected adverse EAT proteomics and identified patients at risk of developing POAF.


Asunto(s)
Estenosis de la Válvula Aórtica , Fibrilación Atrial , Remodelación Atrial , Tejido Adiposo/diagnóstico por imagen , Tejido Adiposo/metabolismo , Estenosis de la Válvula Aórtica/complicaciones , Estenosis de la Válvula Aórtica/diagnóstico por imagen , Estenosis de la Válvula Aórtica/cirugía , Fibrilación Atrial/diagnóstico por imagen , Fibrilación Atrial/epidemiología , Fibrilación Atrial/cirugía , Humanos , Fenotipo , Proteómica
3.
Mol Cell Biochem ; 476(11): 3963-3974, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34191232

RESUMEN

Intravascular hemolysis, a major manifestation of sickle cell disease (SCD) and other diseases, incurs the release of hemoglobin and heme from red blood cells, in turn triggering inflammatory processes. This study investigated the in vitro effects of heme, a major inflammatory DAMP, on the adhesive properties of isolated human neutrophils. Heme (20 and 50 µM) significantly increased the adhesion of neutrophils to fibronectin and to recombinant ICAM-1, under static conditions, even more efficiently than the potent pro-inflammatory cytokine, tumor necrosis factor-α (TNF); a microfluidic assay confirmed that heme stimulated neutrophil adhesion under conditions of shear stress. Heme-induced neutrophil adhesion was associated with the increased activities, but not expressions, of the Mac-1 and LFA-1 integrin subunits, CD11b and CD11a, on the cell surface. Notably, heme (50 µM) significantly induced NFκB translocation in neutrophils, and inhibition of NFκB activity with the BAY11-7082 molecule abolished heme-induced cell adhesion to fibronectin and significantly decreased CD11a activity. Flow cytometric analysis demonstrated major reactive oxygen species (ROS) generation in neutrophils following heme stimulation that could be inhibited by the antioxidant, α-tocopherol, and by BAY11-7082. Furthermore, co-incubation with α-tocopherol abrogated both heme-stimulated neutrophil adhesion and CD11a/CD11b activation. Thus, our data indicate that heme, at clinically relevant concentrations, is a potent activator of neutrophil adhesion, increasing the ligand affinity of the ß2 integrins via a mechanism that may be partially mediated by an NFkB-dependent pathway and the generation of ROS. Given the fundamental role that the adhesion of neutrophils to the vascular wall plays in SCD vaso-occlusion and other vascular inflammatory processes, our findings provide further evidence that cell-free heme is a major therapeutic target in the hemolytic diseases.


Asunto(s)
Endotelio Vascular/efectos de los fármacos , Hemo/farmacología , FN-kappa B/metabolismo , Neutrófilos/efectos de los fármacos , Especies Reactivas de Oxígeno/metabolismo , Anemia de Células Falciformes/metabolismo , Anemia de Células Falciformes/patología , Antígenos CD18/metabolismo , Adhesión Celular/efectos de los fármacos , Células Cultivadas , Endotelio Vascular/metabolismo , Endotelio Vascular/patología , Hemólisis , Humanos , Molécula 1 de Adhesión Intercelular/metabolismo , Leucocitos Mononucleares , Neutrófilos/metabolismo , Neutrófilos/patología , Transducción de Señal
4.
Eur Heart J Cardiovasc Imaging ; 22(7): 765-776, 2021 06 22.
Artículo en Inglés | MEDLINE | ID: mdl-33400773

RESUMEN

AIMS: Quadricuspid aortic valve (QAV) is a rare abnormality, which may cause aortic regurgitation (AR) requiring surgical intervention in some patients. The characteristics associated with aortic valve functional degeneration in patients with QAV are still unknown. The aim of this study is to describe QAV prevalence, characterize the disease by multimodality imaging, evaluate predictors of severe AR, and assess mid-term prognosis. METHODS AND RESULTS: Retrospective search in imaging exams database of one tertiary centre, for patients diagnosed with QAV between January 2007 and September 2019. QAV was characterized by cardiac computed tomography, transthoracic/transoesophageal echocardiography, and cardiac magnetic resonance. A total of 160 004 exams were reviewed and eight patients with QAV were identified (50% men, mean age 53.5 ± 10.7 years). The prevalence of QAV was 0.005%. During a median follow-up of 52 months (interquartile range 16-88), there were no deaths. Seven patients (88%) had pure AR (three severe, one moderate, and three mild) and one patient (12%) had moderate AR and moderate aortic stenosis. Three patients (38%) with severe AR underwent valve surgery (two replacements and one repair). Analysis of predictors of severe AR was not statistically significant. CONCLUSION: QAV is a rare congenital cardiac defect, with a prevalence of 0.005% in our study. Its predominant functional abnormality was regurgitation and about one-third of the patients required aortic valve surgery. Multimodality imaging may play a pivotal role in assessing patients with QAV with significant valve dysfunction or associated congenital heart disease and improve their treatment strategy.


Asunto(s)
Insuficiencia de la Válvula Aórtica , Válvula Aórtica Cuadricúspide , Adulto , Válvula Aórtica/diagnóstico por imagen , Válvula Aórtica/cirugía , Insuficiencia de la Válvula Aórtica/diagnóstico por imagen , Insuficiencia de la Válvula Aórtica/epidemiología , Insuficiencia de la Válvula Aórtica/cirugía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Prevalencia , Pronóstico , Estudios Retrospectivos , Centros de Atención Terciaria
5.
Rev Port Cardiol (Engl Ed) ; 39(11): 625-633, 2020 Nov.
Artículo en Inglés, Portugués | MEDLINE | ID: mdl-33168363

RESUMEN

INTRODUCTION: Accumulation of epicardial adipose tissue (EAT) is associated with coronary artery disease (CAD) and increased risk of coronary events in asymptomatic subjects and low-risk patients, suggesting that EAT promotes atherosclerosis in its early stage. Recent studies have shown that the presence of CAD affects the properties of adjacent EAT, leading to dynamic changes in the molecular players involved in the interplay between EAT and the coronary arteries over the history of the disease. The role of EAT in late-stage CAD has not been investigated. OBJECTIVES: In a comparative analysis with mediastinal and subcutaneous adipose tissue, we aim to investigate whether the volume of EAT assessed by computed tomography and its proteome assessed by SWATH-MS mass spectrometry are associated with late stages of CAD in an elderly cohort of severe aortic stenosis patients. METHODS: The EPICHEART study (NCT03280433) is a prospective study enrolling patients with severe degenerative aortic stenosis referred for elective aortic valve replacement, whose protocol includes preoperative clinical, nutritional, echocardiographic, cardiac computed tomography and invasive coronary angiographic assessments. During cardiac surgery, samples of EAT and mediastinal and subcutaneous thoracic adipose tissue are collected for proteomics analysis by SWATH-MS. In addition, pericardial fluid and peripheral and coronary sinus blood samples are collected to identify circulating and local adipose tissue-derived biomarkers of CAD. CONCLUSION: We designed a translational study to explore the association of EAT quantity and quality with advanced CAD. We expect to identify new biochemical factors and biomarkers in the crosstalk between EAT and the coronary arteries that are involved in the pathogenesis of late coronary atherosclerosis, especially coronary calcification, which might be translated into new therapeutic targets and imaging tools by biomedical engineering.


Asunto(s)
Enfermedad de la Arteria Coronaria , Tejido Adiposo , Anciano , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Humanos , Pericardio/diagnóstico por imagen , Estudios Prospectivos , Proteómica
6.
Atherosclerosis ; 292: 75-83, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31783201

RESUMEN

BACKGROUND & AIMS: The role of epicardial adipose tissue (EAT) in the pathophysiology of late stage-coronary artery disease (CAD) has not been investigated. We explored the association of EAT volume and its proteome with advanced coronary atherosclerosis. METHODS: The EPICHEART Study prospectively enrolled 574 severe aortic stenosis patients referred to cardiac surgery. Before surgery, EAT volume was quantified by computed tomography (CT). During surgery, epicardial, mediastinal (MAT) and subcutaneous (SAT) adipose tissue samples were collected to explore fat phenotype by analyzing the proteomic profile using SWATH-mass spectrometry; pericardial fluid and peripheral venous blood were also collected. CAD presence was defined as coronary artery stenosis ≥50% in invasive angiography and by CT-derived Agatston coronary calcium score (CCS). RESULTS: EAT volume adjusted for body fat was associated with higher CCS, but not with the presence of coronary stenosis. In comparison with mediastinal and subcutaneous fat depots, EAT exhibited a pro-calcifying proteomic profile in patients with CAD characterized by upregulation of annexin-A2 and downregulation of fetuin-A; annexin-A2 protein levels in EAT samples were also positively correlated with CCS. We confirmed that the annexin-A2 gene was overexpressed in EAT samples of CAD patients and positively correlated with CCS. Fetuin-A gene was not detected in EAT samples, but systemic fetuin-A was higher in CAD than in non-CAD patients, suggesting that fetuin-A was locally downregulated. CONCLUSIONS: In an elderly cohort of stable patients, CCS was associated with EAT volume and annexin-A2/fetuin-A signaling, suggesting that EAT might orchestrate pro-calcifying conditions in the late phases of CAD.


Asunto(s)
Tejido Adiposo/anatomía & histología , Tejido Adiposo/diagnóstico por imagen , Anexina A2/análisis , Anexina A2/fisiología , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Pericardio/anatomía & histología , Pericardio/diagnóstico por imagen , Transducción de Señal , Tomografía Computarizada por Rayos X , Calcificación Vascular/diagnóstico por imagen , alfa-2-Glicoproteína-HS/análisis , alfa-2-Glicoproteína-HS/fisiología , Tejido Adiposo/química , Anciano , Anciano de 80 o más Años , Biomarcadores/análisis , Enfermedad de la Arteria Coronaria/sangre , Enfermedad de la Arteria Coronaria/etiología , Femenino , Humanos , Masculino , Tamaño de los Órganos , Pericardio/química , Estudios Prospectivos , Proteómica , Índice de Severidad de la Enfermedad , Calcificación Vascular/sangre , Calcificación Vascular/etiología
7.
Int Immunopharmacol ; 58: 160-165, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29604489

RESUMEN

Neutrophil adhesion to the vasculature in response to potent inflammatory stimuli, such as TNF-α (TNF), can contribute to atheroprogression amongst other pathophysiological mechanisms. Previous studies have shown that simvastatin, a statin with known pleiotropic anti-inflammatory properties, can partially abrogate the effects of TNF-induced neutrophil adhesion, in association with the modulation of ß2-integrin expression. We aimed to further characterize the effects of this statin on neutrophil and leukocyte adhesive mechanisms in vitro and in vivo. A microfluidic assay confirmed the ability of simvastatin to inhibit TNF-induced human neutrophil adhesion to fibronectin ligand under conditions of shear stress, while intravital imaging microscopy demonstrated an abrogation of leukocyte recruitment by simvastatin in the microvasculature of mice that had received a TNF stimulus. This inhibition of neutrophil adhesion was accompanied by the inhibition of TNF-induced RhoA activity in human neutrophils, and alterations in cell morphology and ß2-integrin activity. Additionally, TNF augmented the activity of the p50 NFκB subunit in human neutrophils and TNF-induced neutrophil adhesion and ß2-integrin activity could be abolished using pharmacological inhibitors of NFκB translocation, BAY11-7082 and SC514. Accordingly, the TNF-induced elevation of neutrophil p50 activity was abolished by simvastatin. In conclusion, our data provide further evidence of the ability of simvastatin to inhibit neutrophil adhesive interactions in response to inflammatory stimuli, both in vivo and in vitro. Simvastatin appears to inhibit neutrophil adhesion by interfering in TNF-induced cytoskeletal rearrangements, in association with the inhibition of Rho A activity, NFκB translocation and, consequently, ß2-integrin activity.


Asunto(s)
Inhibidores de Hidroximetilglutaril-CoA Reductasas/farmacología , Subunidad p50 de NF-kappa B/metabolismo , Neutrófilos/inmunología , Simvastatina/farmacología , Proteínas de Unión al GTP rho/metabolismo , Animales , Antígenos CD18/metabolismo , Adhesión Celular , Células Cultivadas , Quimiotaxis , Citoesqueleto/metabolismo , Fibronectinas/metabolismo , Humanos , Ratones , Neutrófilos/efectos de los fármacos , Neutrófilos/patología , Transporte de Proteínas , Factor de Necrosis Tumoral alfa/inmunología , Proteína de Unión al GTP rhoA/metabolismo
8.
Catheter Cardiovasc Interv ; 92(3): 533-541, 2018 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-29105953

RESUMEN

OBJECTIVES: Compare final morphology of self-expanding and balloon-expandable prosthesis and association with paravalvular regurgitation (PVR). BACKGROUND: PVR after transcatheter aortic valve replacement (TAVR) remains a frequent complication. A better understanding of the prosthesis geometry may be important to improve selection of the best device for each case and possibly reduce the rates of PVR. METHODS: Retrospective study including patients consecutively submitted to transcatheter aortic valve replacement: August/2007-October/2016. Three months after the procedure a multidetector computed tomography (MDCT) was performed to assess prosthesis geometry: dimensions, eccentricity, and expansion. RESULTS: A total of 147 individuals were included (mean age of 78.8 ± 6.7 and 50.3% males), 57% treated with a self-expanding prosthesis. On the postprocedure MDCT, the self-expanding group had higher eccentricity index (15.0 vs. 7.1%, p < .001) and lower expansion (68.3 vs. 82.8%, p < .001). In that group, the volume of calcium of landing zone had a significant correlation with eccentricity index and under-expansion. Patients with ≥mild PVR presented higher eccentricity (12.6 vs. 7.9%, p < .001) and lower expansion (68 vs. 75%, p = .012). Eccentricity index and landing zone calcium volume were independent predictors of PVR. CONCLUSIONS: Self-expanding prosthesis have greater eccentricity and under-expansion. Calcium burden exerts more influence in the final morphology of that type of valve. Calcification and eccentricity are associated with the development of PVR. These factors should be considered in the selection of the most appropriate type of prosthesis for each scenario.


Asunto(s)
Insuficiencia de la Válvula Aórtica/diagnóstico por imagen , Estenosis de la Válvula Aórtica/cirugía , Válvula Aórtica/patología , Válvula Aórtica/cirugía , Valvuloplastia con Balón , Calcinosis/cirugía , Prótesis Valvulares Cardíacas , Tomografía Computarizada Multidetector , Reemplazo de la Válvula Aórtica Transcatéter/instrumentación , Anciano , Anciano de 80 o más Años , Válvula Aórtica/diagnóstico por imagen , Válvula Aórtica/fisiopatología , Insuficiencia de la Válvula Aórtica/etiología , Insuficiencia de la Válvula Aórtica/fisiopatología , Estenosis de la Válvula Aórtica/diagnóstico por imagen , Estenosis de la Válvula Aórtica/fisiopatología , Valvuloplastia con Balón/efectos adversos , Calcinosis/diagnóstico por imagen , Calcinosis/fisiopatología , Femenino , Hemodinámica , Humanos , Masculino , Valor Predictivo de las Pruebas , Diseño de Prótesis , Falla de Prótesis , Recuperación de la Función , Estudios Retrospectivos , Factores de Riesgo , Factores de Tiempo , Reemplazo de la Válvula Aórtica Transcatéter/efectos adversos , Resultado del Tratamiento
9.
J Leukoc Biol ; 103(1): 87-98, 2018 01.
Artículo en Inglés | MEDLINE | ID: mdl-28798145

RESUMEN

Although essential for inflammatory responses, leukocyte recruitment to blood vessel walls in response to inflammatory stimuli, such as TNF-α, can contribute to vascular occlusion in inflammatory diseases, including atherosclerosis. We aimed to further characterize the mechanisms by which TNF stimulates adhesive and morphologic alterations in neutrophils. Microfluidic and intravital assays confirmed the potent effect that TNF has on human and murine neutrophil adhesion and recruitment in vitro and in vivo, respectively. Inhibition of actin polymerization by cytochalasin D significantly diminished TNF-induced human neutrophil adhesion in vitro and abolished TNF-induced membrane alterations and cell spreading. In contrast, TNF-induced increases in ß2-integrin (Mac-1 and LFA-1) expression was not significantly altered by actin polymerization inhibition. Consistent with a role for cytoskeletal rearrangements in TNF-induced adhesion, TNF augmented the activity of the Rho GTPase, RhoA, in human neutrophils. However, inhibition of the major RhoA effector protein, Rho kinase (ROCK), by Y-27632 failed to inhibit TNF-induced neutrophil adhesion. In contrast, the formin FH2 domain inhibitor, SMIFH2, abolished TNF-induced human neutrophil adhesion and diminished leukocyte recruitment in vivo. SMIFH2 also inhibited TNF-induced cytoskeletal reorganization in human neutrophils and abolished the alterations in ß2-integrin expression elicited by TNF stimulation. As such, Rho GTPase/mDia formin-mediated cytoskeletal reorganization appears to participate in the orchestration of TNF-induced neutrophil-adhesive interactions, possibly mediated by formin-mediated actin nucleation and subsequent modulation of ß2-integrin activity on the neutrophil surface. This pathway may represent a pharmacologic target for reducing leukocyte recruitment in inflammatory diseases.


Asunto(s)
Citoesqueleto de Actina/fisiología , Antígenos CD18/metabolismo , Adhesión Celular , Proteínas Fetales/metabolismo , Proteínas de Microfilamentos/metabolismo , Neutrófilos/fisiología , Proteínas Nucleares/metabolismo , Factor de Necrosis Tumoral alfa/farmacología , Proteína de Unión al GTP rhoA/metabolismo , Citoesqueleto de Actina/efectos de los fármacos , Adolescente , Adulto , Animales , Antígenos CD18/genética , Células Cultivadas , Proteínas Fetales/genética , Forminas , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Proteínas de Microfilamentos/genética , Persona de Mediana Edad , Neutrófilos/citología , Neutrófilos/efectos de los fármacos , Proteínas Nucleares/genética , Transducción de Señal , Adulto Joven , Proteína de Unión al GTP rhoA/genética
10.
Int J Cardiol ; 249: 419-425, 2017 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-28986055

RESUMEN

BACKGROUND: The association of epicardial adipose tissue (EAT) and coronary artery calcification (CAC) seems to differ by gender. However, few studies have controlled for body size, and the ideal method for body size indexing has not been explored. OBJECTIVES: To analyse the effect of gender related-body size and-body fat differences on the association of EAT with CAC. METHODS: This was a prospective cohort of 371 severe aortic stenosis patients (77±8.5year-old, 51% females) referred to cardiac surgery. Agatston calcium score, EAT volume and visceral abdominal fat (VAF) were obtained by computed tomography. Body composition was determined using bioelectrical impedance analysis. Body weight and height were measured to derive body mass index (BMI), body surface area (BSA), and body surface index (BSI). EAT volume was normalized for BSA, weight and height. RESULTS: Median CAC score was higher in men (887; IQR: 2010) than in women (279: IQR: 145) (p<0.01). Similarly, men had higher volume of EAT than women (137±65.6 vs. 106±65.6mL, p<0.01), even when BSA- or height-indexed, but not if weight-indexed. EAT volume was associated with CAC adjusting for adiposity (BMI or BSI and VAF, or fat mass), but not with further adjustment for gender. In a stratified analysis, absolute- and indexed-volumes of EAT were independently associated with CAC in men while no association was found in women (gender-interaction p<0.05). CONCLUSIONS: In these high-risk patients, we demonstrated that EAT was associated with CAC score irrespective of body size, body fat and cardiovascular risk factors in men but not in women.


Asunto(s)
Tejido Adiposo/diagnóstico por imagen , Estenosis de la Válvula Aórtica/diagnóstico por imagen , Válvula Aórtica/patología , Calcinosis/diagnóstico por imagen , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Pericardio/diagnóstico por imagen , Caracteres Sexuales , Calcificación Vascular/diagnóstico por imagen , Tejido Adiposo/fisiopatología , Anciano , Anciano de 80 o más Años , Válvula Aórtica/diagnóstico por imagen , Válvula Aórtica/fisiopatología , Estenosis de la Válvula Aórtica/fisiopatología , Composición Corporal/fisiología , Calcinosis/fisiopatología , Estudios de Cohortes , Enfermedad de la Arteria Coronaria/fisiopatología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pericardio/fisiopatología , Estudios Prospectivos , Calcificación Vascular/fisiopatología
11.
JACC Cardiovasc Imaging ; 6(10): 1062-1071, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-24011773

RESUMEN

OBJECTIVES: This study sought to compare computed tomography delayed enhancement (CTDE) against cardiac magnetic resonance (CMR) late gadolinium enhancement (LGE) for detection of ischemic scar and to test the additive value of CTDE as part of a comprehensive multidetector computed tomography (MDCT) stress-rest protocol including computed tomography perfusion (CTP) and computed tomography angiography (CTA) for the diagnosis of significant coronary artery disease (CAD). BACKGROUND: CTDE has been recently described as a promising tool for noninvasive detection of myocardial scar, similarly to CMR-LGE techniques. Despite its theoretical potential as an adjunctive tool to improve MDCT accuracy for detection of CAD, its clinical performance has not been validated. METHODS: One hundred five symptomatic patients with suspected CAD (age 62.0 ± 8.0 years, 67% men) underwent MDCT, CMR, and x-ray invasive coronary angiography. The MDCT protocol consisted of calcium scoring, stress CTP under adenosine 140 µg/kg/min, rest CTP + CTA, and a low-dose radiation prospective scan for detection of CTDE. CMR-LGE was used as the reference standard for assessment of scar. Functionally significant CAD was defined as the presence of ≥90% stenosis/occlusion or fractional flow reserve measurements ≤0.80 in vessels >2 mm. RESULTS: CTDE had good accuracy (90%) for ischemic scar detection with low sensitivity (53%) but excellent specificity (98%). Positive and negative predictive values were 82% and 91%, respectively. On a patient-based model, MDCT protocol without integration of CTDE results had a sensitivity, specificity, and positive and negative predictive values of 90%, 81%, 80%, and 90%, respectively, for the detection of functionally significant CAD. Addition of CTDE results did not improve MDCT performance (90%, 77%, 77%, and 90%, respectively). CONCLUSIONS: CTDE has moderate accuracy for detection of ischemic scar in patients with suspected CAD. Integration of CTDE into a comprehensive MDCT protocol including stress-rest CTP and CTA does not improve MDCT accuracy for detection of significant CAD in intermediate-to-high pre-test probability populations.


Asunto(s)
Adenosina , Cicatriz/diagnóstico , Angiografía Coronaria/métodos , Enfermedad de la Arteria Coronaria/diagnóstico , Tomografía Computarizada Multidetector , Isquemia Miocárdica/diagnóstico , Imagen de Perfusión Miocárdica/métodos , Dosis de Radiación , Vasodilatadores , Adulto , Anciano , Cicatriz/diagnóstico por imagen , Cicatriz/patología , Medios de Contraste , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Enfermedad de la Arteria Coronaria/patología , Enfermedad de la Arteria Coronaria/fisiopatología , Femenino , Reserva del Flujo Fraccional Miocárdico , Humanos , Imagen por Resonancia Cinemagnética , Masculino , Persona de Mediana Edad , Isquemia Miocárdica/diagnóstico por imagen , Isquemia Miocárdica/patología , Isquemia Miocárdica/fisiopatología , Miocardio/patología , Valor Predictivo de las Pruebas , Estudios Prospectivos , Índice de Severidad de la Enfermedad
12.
Peptides ; 34(1): 158-67, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21802465

RESUMEN

During their evolution, animals have developed a set of cysteine-rich peptides capable of binding various extracellular sites of voltage-gated sodium channels (VGSC). Sea anemone toxins that target VGSCs delay their inactivation process, but little is known about their selectivities. Here we report the investigation of three native type 1 toxins (CGTX-II, δ-AITX-Bcg1a and δ-AITX-Bcg1b) purified from the venom of Bunodosoma cangicum. Both δ-AITX-Bcg1a and δ-AITX-Bcg1b toxins were fully sequenced. The three peptides were evaluated by patch-clamp technique among Nav1.1-1.7 isoforms expressed in mammalian cell lines, and their preferential targets are Na(v)1.5>1.6>1.1. We also evaluated the role of some supposedly critical residues in the toxins which would interact with the channels, and observed that some substitutions are not critical as expected. In addition, CGTX-II and δ-AITX-Bcg1a evoke different shifts in activation/inactivation Boltzmann curves in Nav1.1 and 1.6. Moreover, our results suggest that the interaction region between toxins and VGSCs is not restricted to the supposed site 3 (S3-S4 linker of domain IV), and this may be a consequence of distinct surface of contact of each peptide vs. targeted channel. Our data suggest that the contact surfaces of each peptide may be related to their surface charges, as CGTX-II is more positive than δ-AITX-Bcg1a and δ-AITX-Bcg1b.


Asunto(s)
Péptidos/química , Péptidos/farmacología , Isoformas de Proteínas/metabolismo , Anémonas de Mar/metabolismo , Canales de Sodio/metabolismo , Secuencia de Aminoácidos , Animales , Línea Celular , Electrofisiología , Humanos , Espectrometría de Masas , Datos de Secuencia Molecular , Isoformas de Proteínas/efectos de los fármacos , Canales de Sodio/efectos de los fármacos , Relación Estructura-Actividad
13.
Pharmacol Biochem Behav ; 91(2): 252-60, 2008 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-18778727

RESUMEN

Crotoxin (CTX), a neurotoxin isolated from the venom of the South American rattlesnake Crotalus durissus terrificus, induces analgesia. In this study, we evaluated the antinociceptive effect of CTX in a model of neuropathic pain induced by rat sciatic nerve transection. Hyperalgesia was detected 2 h after nerve transection and persisted for 64 days. Immersion of proximal and distal nerve stumps in CTX solution (0.01 mM for 10 s), immediately after nerve transection, blocked hyperalgesia. The antinociceptive effect of CTX was long-lasting, since it was detected 2 h after treatment and persisted for 64 days. CTX also delayed, but did not block, neurectomy-induced neuroma formation. The effect of CTX was blocked by zileuton (100 mg/kg, p.o.) and atropine (10 mg/kg, i.p.), and reduced by yohimbine (2 mg/kg, i.p.) and methysergide (5 mg/kg, i.p.). On the other hand, indomethacin (4 mg/kg, i.v.), naloxone (1 mg/kg, i.p.), and N-methyl atropine (30 mg/kg, i.p.) did not interfere with the effect of CTX. These results indicate that CTX induces a long-lasting antinociceptive effect in neuropathic pain, which is mediated by activation of central muscarinic receptors and partially, by activation of alpha-adrenoceptors and 5-HT receptors. Eicosanoids derived from the lipoxygenase pathway modulate the action of crotoxin.


Asunto(s)
Analgésicos no Narcóticos , Araquidonato 5-Lipooxigenasa/fisiología , Crotoxina/farmacología , Dolor/tratamiento farmacológico , Dolor/etiología , Enfermedades del Sistema Nervioso Periférico/complicaciones , Receptores Muscarínicos/efectos de los fármacos , Animales , Antiinflamatorios no Esteroideos/farmacología , Araquidonato 5-Lipooxigenasa/metabolismo , Creatina Quinasa/sangre , Creatina Quinasa/metabolismo , Eicosanoides/metabolismo , Eicosanoides/fisiología , Hiperalgesia/tratamiento farmacológico , Hiperalgesia/psicología , Indometacina/farmacología , Masculino , Actividad Motora/efectos de los fármacos , Agonistas Muscarínicos/farmacología , Antagonistas Muscarínicos/farmacología , Naloxona/farmacología , Antagonistas de Narcóticos/farmacología , Umbral del Dolor/efectos de los fármacos , Ratas , Nervio Ciático/lesiones , Serotonina/fisiología
14.
Biochim Biophys Acta ; 1764(10): 1592-600, 2006 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-17015047

RESUMEN

Sea anemones produce a wide variety of biologically active compounds, such as the proteinaceous neurotoxins and cytolysins. Herein we report a new peptide, purified to homogeneity from the neurotoxic fraction of B. caissarum venom, by using gel filtration followed by rp-HPLC, naming it as BcIV. BcIV is a 41 amino acid peptide (molecular mass of 4669 amu) possessing 6 cysteines covalently linked by three disulfide bonds. This toxin has 45 and 48% of identity when compared to APETx1 and APETx2 from Anthopleura elegantissima, respectively, and 42% of identity with Am-II and BDS-I and-II obtained from Antheopsis maculata and Anemonia sulcata, respectively. This neurotoxin presents only a weak-paralyzing action (minimal Lethal Dose close to 2000 microg/kg) in swimming crabs Callinectes danae. This appears to be a different effect to that caused by the type 1 sea anemone toxin BcIII that is lethal to the same animals at lower doses (LD50=219 microg/kg). Circular dichroism spectra of BcIII and BcIV show a high content of beta-strand secondary structure in both peptides, very similar to type 1 sodium channel toxins from various sea anemones, and to APETx1 and APETx2 from A. elegantissima, a HERG channel modulator and an ASIC3 inhibitor, respectively. Interestingly, BcIII and BcIV have similar effects on the action potential of the crab leg nerves, suggesting the same target in this tissue. As BcIII was previously reported as a Na+ channel effector and BcIV is inactive over Na+ currents of mammalian GH3 cells, we propose a species-specific action for this new molecule. A molecular model of BcIV was constructed using the structure of the APETx1 as template and putative key residues are discussed.


Asunto(s)
Venenos de Cnidarios/química , Toxinas Marinas/química , Toxinas Marinas/toxicidad , Neurotoxinas/química , Neurotoxinas/toxicidad , Canales de Sodio/efectos de los fármacos , Secuencia de Aminoácidos , Animales , Bioensayo , Braquiuros/efectos de los fármacos , Dicroismo Circular , Venenos de Cnidarios/toxicidad , Electrofisiología , Dosificación Letal Mediana , Toxinas Marinas/aislamiento & purificación , Modelos Moleculares , Datos de Secuencia Molecular , Neurotoxinas/aislamiento & purificación , Parálisis/inducido químicamente , Péptidos/química , Péptidos/aislamiento & purificación , Péptidos/toxicidad , Anémonas de Mar/metabolismo
15.
Rev. Soc. Bras. Med. Trop ; 36(5): 633-634, set.-out. 2003.
Artículo en Inglés | LILACS | ID: lil-348039

RESUMEN

The present communication reports the presence of Lutzomyia longipalpis in Corumbá, Mato Grosso do Sul, where the principal vector is Lutzomyia cruzi


Asunto(s)
Animales , Insectos Vectores , Leishmaniasis Visceral , Psychodidae , Brasil
16.
Arq. bras. med ; 60(3): 251-6, maio-jun. 1986. tab, ilus
Artículo en Portugués | LILACS | ID: lil-35782

RESUMEN

Faz-se uma revisäo clínico-farmacológica do cloridrato de buflomedil, importante molécula vasoativa, sobretudo ao nível da microcirculaçäo


Asunto(s)
Pirrolidinas/farmacología , Química , Microcirculación/efectos de los fármacos , Pirrolidinas/toxicidad
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