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1.
J Card Fail ; 30(3): 425-435, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37678704

RESUMEN

BACKGROUND: Treatment of patients with heart failure with reduced ejection fraction (HFrEF) and renal dysfunction (RD) is challenging owing to the risk of further deterioration in renal function, especially after acute decompensated HF (ADHF). METHODS AND RESULTS: We assessed the effect of RD (estimated glomerular filtration rate of ≥30 to <60 mL/min/1.73 m2) on initiation, up-titration, and tolerability of sacubitril/valsartan in hemodynamically stabilized patients with HFrEF admitted for ADHF (RD, n = 476; non-RD, n = 483). At week 10, the target dose of sacubitril/valsartan (97/103 mg twice daily) was achieved by 42% patients in RD subgroup vs 54% in non-RD patients (P < .001). Sacubitril/valsartan was associated with greater estimated glomerular filtration rate improvements in RD subgroup than non-RD (change from baseline least squares mean 4.1 mL/min/1.73 m2, 95% confidence interval 2.2-6.1, P < .001). Cardiac biomarkers improved significantly in both subgroups; however, compared with the RD subgroup, the improvement was greater in those without RD (N-terminal pro-brain natriuretic peptide, -28.6% vs -44.8%, high-sensitivity troponin T -20.3% vs -33.9%) (P < .001). Patients in the RD subgroup compared with those without RD experienced higher rates of hyperkalemia (16.3% vs 6.5%, P < .001), investigator-reported cardiac failure (9.7% vs 5.6%, P = .029), and renal impairment (6.4% vs 2.1%, P = .002). CONCLUSIONS: Most patients with HFrEF and concomitant RD hospitalized for ADHF tolerated early initiation of sacubitril/valsartan and showed significant improvements in estimated glomerular filtration rate and cardiac biomarkers. CLINICAL TRIAL REGISTRATION: NCT02661217.


Asunto(s)
Insuficiencia Cardíaca , Enfermedades Renales , Disfunción Ventricular Izquierda , Humanos , Aminobutiratos/efectos adversos , Antagonistas de Receptores de Angiotensina , Biomarcadores , Compuestos de Bifenilo , Combinación de Medicamentos , Volumen Sistólico , Tetrazoles/efectos adversos , Resultado del Tratamiento , Valsartán , Disfunción Ventricular Izquierda/tratamiento farmacológico
2.
Vascul Pharmacol ; 148: 107140, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36563732

RESUMEN

Advanced heart failure (HF) is associated with a very poor prognosis and places a big burden on health-care services. The gold standard treatment, i.e. long-term mechanical circulatory support or heart transplantation, is precluded in many patients but observational studies suggest that the use of SNP might be associated with favourable long-term clinical outcomes. We performed a metanalysis of published studies that compared sodium nitroprusside (SNP) with optimal medical therapy to examine the safety and efficacy of SNP as part of the treatment regimen of patients hospitalized for advanced heart failure (HF). We searched PUBMED, EMBASE and WEB OF SCIENCE for studies that compared SNP with optimal medical therapy in advanced HF on July 2022. After screening 700 full-text articles, data from two original articles were included in a combined analysis. The analysis demonstrated a 66% reduction in the odds of death in advanced HF patients treated with SNP. The results show the potential importance of the inclusion of SNP in the treatment regimen of patients hospitalized because of advanced HF and underlines that controlled, randomized studies are still required in this condition.


Asunto(s)
Insuficiencia Cardíaca , Humanos , Nitroprusiato/efectos adversos , Insuficiencia Cardíaca/diagnóstico , Insuficiencia Cardíaca/tratamiento farmacológico , Pronóstico
3.
J Arrhythm ; 37(2): 407-413, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33821178

RESUMEN

Background: Coronavirus Disease-2019 (COVID-19) has been associated with myocardial injury and higher risk of arrhythmic complications. However, no reports are available about the effect of the ongoing pandemic on arrhythmias in patients at risk. Objective: To describe the effect of COVID-19 pandemic on arrhythmic burden among high-risk patients. Methods: This is a cross-sectional study on the incidence of ventricular arrhythmia (VA) during the pandemic outbreak (study period), compared to the same timeframe in 2019 (reference period). Inclusion criteria were age (>18 years) and having an implantable cardiac defibrillator (ICD). Results: Among 455 patients enrolled (mean age 64.9 ± 15.7 years; 25.1% females and 39.6% with CRTD), in the study period, 45 (9.9%) patients experienced a total of 86 VA; 8 patients (1.7%) required antitachycardia-pacing (ATP) and 6 (1.3%) at least one shock. In the reference period, a total of 69 events occurred in 36 patients (7.9%). Six patients (1.3%) required ATP and three (0.7%) at least one shock. The number of patients that suffered from any arrhythmic events in the study period (9.9% vs 7.9%) did not significantly differ from the reference period (χ2 = 1.09, P = .29). The main predictor of VA during the COVID-19 pandemic was the previous history of any ICD therapy (OR = 3.84, P < .001). Conclusions: No evidence of an increase of arrhythmic burden was found during the COVID-19 pandemic among patients with an ICD.

4.
Indian Heart J ; 72(2): 82-92, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32534694

RESUMEN

We aimed to characterize the epidemiology, diagnostic peculiarities and outcome determinants of bacterial myocarditis. Two cases from our institution and literature reports were collected ending up with a total of 66 cases. In 37 (56%) patients, the diagnosis was confirmed by magnetic resonance and histopathological criteria. The other patients were classified as having possible myocarditis. Only occurrence of rhythm disturbances was associated with the specific diagnosis of myocarditis (p = 0.04). Thirty-two (48%) patients presented with severe sepsis that was associated with a worse prognosis. At multivariate analysis, left ventricular ejection fraction (LVEF) at admission and heart rhythm disturbances were associated with incomplete recovery (odds ratio (OR) 1.1, 95% (CI) 1.03-1.2, p = 0.004 and OR 6.6, 95% CI 1.35-32.5, p = 0.02, respectively). In summary, bacterial myocarditis is uncommon. Most commonly, it is secondary to septic dissemination of bacteria or to transient secondary myocardial toxicity.


Asunto(s)
Infecciones Bacterianas/diagnóstico , Ventrículos Cardíacos/diagnóstico por imagen , Imagen por Resonancia Cinemagnética/métodos , Miocarditis/diagnóstico , Volumen Sistólico/fisiología , Función Ventricular Izquierda/fisiología , Enfermedad Aguda , Adulto , Infecciones Bacterianas/epidemiología , Infecciones Bacterianas/fisiopatología , Electrocardiografía , Femenino , Ventrículos Cardíacos/fisiopatología , Humanos , Incidencia , Italia/epidemiología , Masculino , Persona de Mediana Edad , Miocarditis/epidemiología , Miocarditis/fisiopatología , Estudios Retrospectivos
5.
Scand J Med Sci Sports ; 27(11): 1411-1416, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-27747933

RESUMEN

Athletes may have electrocardiogram (ECG) repolarization abnormalities during stress test suggestive for ischemia in the absence of ischemic coronary artery disease, often in a setting of myocardial septum hypertrophy. Global longitudinal strain (GLS) might be altered in these athletes compared to hypertensive patients with the same degree of septal thickness. About 735 consecutive athletes were screened for mandatory assessment of fitness to participate in competitive sports. At the stress test, 23 (19 M, 4 F) were found to have ECG repolarization abnormalities suggestive for ischemia in the presence of normal coronary vessels. They were matched to a control group of 23 hypertensive patients with no ECG abnormalities during stress test and the same degree of septal thickness. A transthoracic echocardiography for evaluation of global longitudinal strain (GLS) was performed. Interventricular septum thickness (IST) and relative wall thickness (RWT) were also calculated. A preserved ventricular function was seen in both groups (64 ± 8% in cases vs 60 ± 6% in controls, P = 0.42). IST and RWT were not significantly different. GLS was significantly lower in athletes vs hypertensive patients (-18.7 ± 2.5 vs -21.67 ± 0.27, P = 0.001). In athletes with septal hypertrophy and a positive stress test not associated to coronary disease, GLS is lower with respect to a population of hypertensive patient with the same degree of septal hypertrophy. Further investigations in a larger population are required to better define the potentiality of GLS in differentiating pathological vs physiological septum hypertrophy.


Asunto(s)
Tabiques Cardíacos/patología , Hipertensión/fisiopatología , Miocardio/patología , Aptitud Física , Adulto , Atletas , Ecocardiografía , Prueba de Esfuerzo , Femenino , Corazón/diagnóstico por imagen , Tabiques Cardíacos/diagnóstico por imagen , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos
7.
Thromb Haemost ; 114(2): 423-31, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26017898

RESUMEN

When patients with coronary stents undergo non-cardiac surgery, bridging therapy with low-molecular-weight heparin (LMWH) is not infrequent in clinical practice. However, the efficacy and safety of this approach is poorly understood. This was a retrospective analysis of patients with coronary stent(s) on any antiplatelet therapy undergoing non-cardiac surgery between March 2003 and February 2012. The primary efficacy endpoint was the 30-day incidence of major adverse cardiac or cerebrovascular events (MACCE), defined as the composite of cardiac death, myocardial infarction, acute coronary syndrome leading to hospitalisation, or stroke. The primary safety endpoint was the 30-day composite of Bleeding Academic Research Consortium (BARC) bleedings ≥ 2. Among 515 patients qualifying for the analysis, LMWH bridging was used in 251 (49 %). At 30 days, MACCE occurred more frequently in patients who received LMWH (7.2 % vs 1.1 %, p=0.001), driven by a higher rate of myocardial infarction (4.8 % vs 0 %, p< 0.001). This finding was consistent across several instances of statistical adjustment and after the propensity matching of 179 pairs. Patients bridged with LMWH also experienced a significantly higher risk of BARC bleedings ≥ 2 (21.9 % vs 11.7 %, p=0.002) compared to those who were not, which remained significant across different methods of statistical adjustment and propensity matching. In conclusion, LMWH bridging in patients with coronary stents undergoing surgery is a common and possibly harmful practice, resulting in worse ischaemic outcomes at 30 days, and a significant risk of bleeding.


Asunto(s)
Sustitución de Medicamentos/efectos adversos , Procedimientos Quirúrgicos Electivos , Cardiopatías/mortalidad , Hemorragia/inducido químicamente , Heparina de Bajo-Peso-Molecular/efectos adversos , Complicaciones Posoperatorias/epidemiología , Premedicación/efectos adversos , Stents , Accidente Cerebrovascular/epidemiología , Síndrome Coronario Agudo/epidemiología , Síndrome Coronario Agudo/etiología , Anciano , Aspirina/administración & dosificación , Comorbilidad , Enfermedad Coronaria/complicaciones , Enfermedad Coronaria/cirugía , Reestenosis Coronaria/epidemiología , Reestenosis Coronaria/etiología , Femenino , Cardiopatías/etiología , Hemorragia/epidemiología , Heparina de Bajo-Peso-Molecular/uso terapéutico , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/epidemiología , Infarto del Miocardio/etiología , Intervención Coronaria Percutánea , Inhibidores de Agregación Plaquetaria/administración & dosificación , Complicaciones Posoperatorias/inducido químicamente , Complicaciones Posoperatorias/tratamiento farmacológico , Puntaje de Propensión , Estudios Retrospectivos , Factores de Riesgo , Accidente Cerebrovascular/etiología , Trombofilia/tratamiento farmacológico , Trombofilia/etiología , Resultado del Tratamiento
10.
Abdom Imaging ; 32(6): 775-83, 2007 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-17151893

RESUMEN

Pelvic magnetic resonance is a simple and non-invasive imaging technique for dynamic and static assessment of the pelvic floor. The morphology of the support system is assessed by T2-weighted images. Dynamic sequences are used to assess pelvic prolapse. In this study we illustrate the normal and pathologic features of the levator ani muscle which represents the main active support of pelvic organs. Furthermore we describe the different types of prolapses, floor by floor, and the different staging techniques.


Asunto(s)
Imagen por Resonancia Magnética/métodos , Prolapso de Órgano Pélvico/diagnóstico , Femenino , Humanos , Diafragma Pélvico
11.
J Cell Physiol ; 207(2): 379-88, 2006 May.
Artículo en Inglés | MEDLINE | ID: mdl-16419034

RESUMEN

Adult skeletal muscle fibers can be divided into fast and slow twitch subtypes on the basis of specific contractile and metabolic properties, and on distinctive patterns of muscle gene expression. The calcium, calmodulin-dependent protein phosphatase, calcineurin, stimulates slow fiber-specific genes (myoglobin (Mb), troponin I slow) in cultured skeletal muscle cells, as well as in transgenic mice, through the co-operation of peroxisome-proliferation-activator receptor gamma co-activator 1alpha (PGC1alpha) myocyte enhancer factor 2 (MEF2), and nuclear factor of activated T cells (NFAT) transcription factors. Specific protein kinase C isoforms have been shown to functionally co-operate with calcineurin in different cellular models. We investigated whether specific protein kinase C isoforms are involved in calcineurin-induced slow skeletal muscle gene expression. By pharmacological inhibition or exogenous expression of mutant forms, we show that protein kinase C theta (the protein kinase C isoform predominantly expressed in skeletal muscle) is required and co-operates with calcineurin in the activation of the Mb promoter, as well as in the induction of slow isoforms of myosin and troponin I expression, in cultured muscle cells. This co-operation acts primarily regulating MEF2 activity, as shown by using reporter gene expression driven by the Mb promoter mutated in the specific binding sites. MEF2 activity on the Mb promoter is known to be dependent on both PGC1alpha and inactivation of histone deacetylases (HDACs) activity. We show in this study that protein kinase C theta is required for, even though it does not co-operate in, PGC1alpha-dependent Mb activation. Importantly, protein kinase C theta regulates the HDAC5 nucleus/cytoplasm location. We conclude that protein kinase C theta ensures maximal activation of MEF2, by regulating both MEF2 transcriptional complex formation and HDACs nuclear export.


Asunto(s)
Calcineurina/farmacología , Isoenzimas/metabolismo , Fibras Musculares de Contracción Lenta/metabolismo , Mioblastos/metabolismo , Proteína Quinasa C/metabolismo , Transporte Activo de Núcleo Celular/efectos de los fármacos , Animales , Calcineurina/genética , Carbazoles/farmacología , Línea Celular , Inhibidores Enzimáticos/farmacología , Regulación de la Expresión Génica/efectos de los fármacos , Inhibidores de Histona Desacetilasas , Histona Desacetilasas/genética , Histona Desacetilasas/metabolismo , Ácidos Hidroxámicos/farmacología , Indoles/farmacología , Isoenzimas/antagonistas & inhibidores , Isoenzimas/genética , Factores de Transcripción MEF2 , Ratones , Fibras Musculares de Contracción Lenta/efectos de los fármacos , Mutación , Mioblastos/citología , Mioblastos/efectos de los fármacos , Factores Reguladores Miogénicos/genética , Mioglobina/genética , Coactivador 1-alfa del Receptor Activado por Proliferadores de Peroxisomas gamma , Proteína Quinasa C/antagonistas & inhibidores , Proteína Quinasa C/genética , Proteína Quinasa C-theta , Proteínas de Unión al ARN/genética , Ratas , Transactivadores/genética , Factores de Transcripción/genética , Transfección , Troponina I/genética
12.
J Cell Physiol ; 196(1): 89-97, 2003 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-12767044

RESUMEN

Protein kinase C theta (PKC-theta) is the PKC isoform predominantly expressed in skeletal muscle, and it is supposed to mediate many signals necessary for muscle histogenesis and homeostasis, such as TGFbeta, nerve-dependent signals and insulin. To study the role of PKC-theta in these mechanisms we generated transgenic mice expressing a "kinase dead" mutant form of PKC-theta (PKC-thetaK/R), working as "dominant negative," specifically in skeletal muscle. These mice are viable and fertile, however, by the 6-7 months of age, they gain weight, mainly due to visceral fat deposition. Before the onset of obesity (4 months of age), they already show increased fasting and fed insulin levels and reduced insulin-sensitivity, as measured by ipITT, but normal glucose tolerance, as measured by ipGTT. After the 6-7 months of age, transgenic mice develop hyperinsulinemia in the fasting and fed state. The ipGTT revealed in the transgenic mice both hyperglycemia and hyperinsulinemia. At the molecular level, impaired activation of the IR/IRS/PI3K pathway and a significant decrease both in the levels and in insulin-stimulated activation of the serine/threonine kinase Akt were observed. Taken together these data demonstrate that over-expression of dominant negative PKC-theta in skeletal muscle causes obesity associated to insulin resistance, as demonstrated by defective receptor and post-receptorial activation of signaling cascade.


Asunto(s)
Modelos Animales de Enfermedad , Genes Dominantes/genética , Resistencia a la Insulina , Isoenzimas/genética , Isoenzimas/metabolismo , Músculo Esquelético/enzimología , Obesidad , Proteína Quinasa C/genética , Proteína Quinasa C/metabolismo , Animales , Glucosa/metabolismo , Insulina/farmacología , Resistencia a la Insulina/genética , Ratones , Ratones Transgénicos , Mutación , Obesidad/genética , Fenotipo , Proteína Quinasa C-theta , Transducción de Señal/efectos de los fármacos
13.
J Am Coll Cardiol ; 38(5): 1277-82, 2001 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-11691495

RESUMEN

Three well-controlled epidemiology studies in the U.S. have reported that 40% of incident congestive heart failure (CHF) cases and 50% to 60% of prevalent CHF cases occur in the setting of preserved systolic function. This condition has been termed "diastolic heart failure" (DHF). Despite minor differences in the types of populations examined, these community-based studies have established DHF as a major health problem in the U.S., particularly among the elderly. Although extensive data are available concerning the natural history of CHF associated with reduced systolic dysfunction (systolic heart failure; SHF), the natural history of DHF is not well-characterized. Indeed, it remains unclear whether patients with DHF share the grim prognosis described for patients with SHF. In this review we examine the available studies comparing survival observed in patients with DHF to that observed in patients with SHF. Although there are insufficient data at present to make definitive conclusions, careful examination of the available studies raises the possibility that the natural history of patients with DHF may not be different from that observed in patients with CHF and reduced systolic function.


Asunto(s)
Diástole , Insuficiencia Cardíaca/fisiopatología , Sístole , Distribución por Edad , Anciano , Progresión de la Enfermedad , Medicina Basada en la Evidencia , Insuficiencia Cardíaca/complicaciones , Insuficiencia Cardíaca/diagnóstico , Insuficiencia Cardíaca/epidemiología , Humanos , Incidencia , Persona de Mediana Edad , Prevalencia , Pronóstico , Proyectos de Investigación/normas , Sesgo de Selección , Volumen Sistólico , Análisis de Supervivencia , Estados Unidos/epidemiología
14.
Eur J Heart Fail ; 3(2): 257-60, 2001 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-11246065

RESUMEN

In Italy, the National Health System is funded from the taxation system of the state. It is organized by general practitioners in the community and specialists in the hospitals. All Italian citizens are registered with one of the general practitioners. Patients with suspected heart failure are generally referred from the family practitioner to a higher level of medical care. Only a minority of patients with heart failure are cared for by cardiologists, either as in- or outpatients. Echocardiography is widely available; nevertheless, few patients admitted to internal medicine divisions receive an echocardiogram compared to cardiology units. The ACE inhibitor usage by Italian cardiologists in patients with heart failure is satisfied, and the use of beta blockers is increasing in Italy at this time. Since only a small proportion of patients with heart failure are followed by cardiologists in Italy, further efforts are necessary until internists and general practitioners could be involved in treatment trials in heart failure. The aim of this approach is to transfer the beneficial effects observed in the trials to clinical practice.


Asunto(s)
Fármacos Cardiovasculares/administración & dosificación , Comparación Transcultural , Insuficiencia Cardíaca/tratamiento farmacológico , Grupo de Atención al Paciente , Antagonistas Adrenérgicos beta/administración & dosificación , Adulto , Anciano , Inhibidores de la Enzima Convertidora de Angiotensina/administración & dosificación , Enfermedad Crónica , Ecocardiografía , Femenino , Insuficiencia Cardíaca/diagnóstico , Humanos , Italia , Masculino , Persona de Mediana Edad
15.
J Heart Valve Dis ; 10(1): 72-7, 2001 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-11206771

RESUMEN

BACKGROUND AND AIM OF THE STUDY: Limited data are available regarding the efficacy of mitral valve repair in patients affected by active, acute infective endocarditis. In addition, the predictivity of transesophageal echocardiography (TEE) for guiding the surgical decision-making process in these patients has not yet been reported. The study aim was to evaluate the long-term results of mitral valve repair and role of TEE in active, acute infective endocarditis. METHODS: The study population consisted of patients affected by infective endocarditis of the mitral valve who underwent surgery. TEE was performed intraoperatively to guide the best surgical approach. All patients were followed up (mean 73+/-8 months) after surgery. RESULTS: Twenty-eight patients underwent surgery for infective endocarditis; of these, 13 had mitral valve repair for active, acute infective endocarditis and formed the basis of the study. Sensitivity, specificity, positive predictive value, negative predictive value of TEE in detecting the mechanism of mitral regurgitation were 87%, 100%, 100% and 92%, respectively. The predictivity test of TEE in guiding surgical strategy was 94%. All patients were alive at the time of follow up; 10 (77%) were in NYHA class I and three in class II (23%). Mitral regurgitation was severe in one patient (8%), moderate in three (23%), mild in four (31%), and absent in five (38%). No relapses of active infective endocarditis were observed during the follow up period. CONCLUSION: Mitral valve repair appears to be an effective treatment for active, acute infective endocarditis with mitral regurgitation and should be considered as a therapeutic strategy when surgery is contemplated. TEE has a fundamental role in the surgical decision-making process in these patients.


Asunto(s)
Ecocardiografía Transesofágica , Endocarditis Bacteriana/cirugía , Insuficiencia de la Válvula Mitral/cirugía , Enfermedad Aguda , Adulto , Anciano , Bioprótesis , Cuerdas Tendinosas/diagnóstico por imagen , Cuerdas Tendinosas/cirugía , Endocarditis Bacteriana/diagnóstico por imagen , Femenino , Implantación de Prótesis de Válvulas Cardíacas , Humanos , Masculino , Persona de Mediana Edad , Insuficiencia de la Válvula Mitral/diagnóstico por imagen , Medición de Riesgo , Rotura Espontánea
17.
Hernia ; 5(3): 124-8, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11759796

RESUMEN

Giant incisional hernias with total loss of substance are an ominous pathological condition characterized by massive depletion of muscular and fascial tissue, by complete loss of the anatomical and physiological function of the abdominal wall and by severe respiratory and visceral involvement. Over a 10-year period we operated 270 patients with voluminous incisional hernias, 12 of which had a total loss of substance. There was no intraoperative mortality. One patient died of myocardial infarction on the fifth and one died of intestinal occlusion and peritonitis the 11th postoperative day. Early postoperative complications occurred in only one patient who had skin necrosis with an infection at the polypropylene mesh. This was successfully treated with systemic antibiotic therapy and topical medication of the wound. There was also one minor recurrence over the pubis 1 year after the operation that required a new operation to replace the mesh. No respiratory complications occurred and all patients were normally active. The good results reported in our series encourage us to continue in this direction even though these patients are at high risk.


Asunto(s)
Hernia Ventral/cirugía , Complicaciones Posoperatorias/cirugía , Prótesis e Implantes , Mallas Quirúrgicas , Anciano , Anciano de 80 o más Años , Femenino , Estudios de Seguimiento , Hernia Ventral/patología , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/etiología , Peritonitis/etiología , Complicaciones Posoperatorias/patología , Infecciones Cutáneas Estafilocócicas/etiología , Staphylococcus aureus/aislamiento & purificación , Mallas Quirúrgicas/microbiología
18.
FASEB J ; 14(9): 1147-58, 2000 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10834937

RESUMEN

Transforming growth factor beta (TGF) is a well-known inhibitor of myogenic differentiation as well as an autocrine product of rhabdomyosarcoma cells. We studied the role of the TGF-beta autocrine loop in regulating growth and myogenic differentiation in the human rhabdomyosarcoma cell line, RD. We previously reported that the phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) induces growth arrest and myogenic differentiation in these cells, which constitutively express muscle regulatory factors. We show that TPA inhibits the activation of secreted latent TGF-beta, thus decreasing the concentration of active TGF-beta to which the cells are exposed. This event is mediated by the TPA-induced alteration of the uPA/PAI serine-protease system. Complete removal of TGF-beta, mediated by the ectopic expression of a soluble type II TGF-beta receptor dominant negative cDNA, induces growth arrest, but does not trigger differentiation. In contrast, a reduction in the TGF-beta concentration, to a range of 0.14-0.20 x 10(-2) ng/ml (which is similar to that measured in TPA-treated cells), mimics TPA-induced differentiation. Taken together, these data demonstrate that cell growth and suppression of differentiation in rhabdomyosarcoma cells require overproduction of active TGF-beta; furthermore, they show that a 'critical' concentration of TGF-beta is necessary for myogenic differentiation to occur, whereas myogenesis is abolished below and above this concentration. By impairing the TGF-beta autocrine loop, TPA stabilizes the factor concentration within the range compatible for differentiation to occur. In contrast, in human primary muscle cells a much higher concentration of exogenous TGF-beta is required for the differentiation inhibitory effect and TPA inhibits differentiation in these cells probably through a TGF-beta independent mechanism. These data thus clarify the mechanism underlying the multiple roles of TGF-beta in the regulation of both the transformed and differentiated phenotype.


Asunto(s)
Comunicación Autocrina/efectos de los fármacos , Diferenciación Celular/efectos de los fármacos , Músculo Esquelético/citología , Rabdomiosarcoma/patología , Factor de Crecimiento Transformador beta/farmacología , Animales , Aprotinina/farmacología , División Celular/efectos de los fármacos , Células Cultivadas , Relación Dosis-Respuesta a Droga , Humanos , Músculo Esquelético/efectos de los fármacos , Músculo Esquelético/metabolismo , Músculo Esquelético/patología , Mutación/genética , Cadenas Pesadas de Miosina/metabolismo , Pepstatinas/farmacología , Plasminógeno/metabolismo , Inactivadores Plasminogénicos/metabolismo , Precursores de Proteínas/genética , Precursores de Proteínas/metabolismo , Procesamiento Proteico-Postraduccional/efectos de los fármacos , Proteínas Serina-Treonina Quinasas , ARN Mensajero/genética , ARN Mensajero/metabolismo , Receptor Tipo II de Factor de Crecimiento Transformador beta , Receptores de Factores de Crecimiento Transformadores beta/genética , Receptores de Factores de Crecimiento Transformadores beta/metabolismo , Rabdomiosarcoma/metabolismo , Acetato de Tetradecanoilforbol/farmacología , Transfección , Factor de Crecimiento Transformador beta/genética , Factor de Crecimiento Transformador beta/metabolismo , Células Tumorales Cultivadas , Activador de Plasminógeno de Tipo Uroquinasa/antagonistas & inhibidores , Activador de Plasminógeno de Tipo Uroquinasa/metabolismo
19.
G Ital Cardiol ; 29(8): 918-24, 1999 Aug.
Artículo en Italiano | MEDLINE | ID: mdl-10488455

RESUMEN

UNLABELLED: Right heart failure due to elevated PVR is one of the major causes of mortality and morbidity after orthotopic heart transplantation. In 5 patients (median age 14 years) with dilated or restrictive cardiomyopathy and important elevation of the PVR, a heterotopic heart transplantation was performed using the technique reported by Yacoub (the donor pulmonary artery was implanted on the recipient right atrium). All the patients presented with at least two of the following parameters: PVR/m2 > 6 U, transpulmonary gradient > 15 mmHg, mean pulmonary pressure > 50 mmHg. One patient with restrictive cardiomyopathy died three months after transplantation of severe failure of the native right ventricle. The other four patients, with a mean follow-up of 29 months, are in good clinical and hemodynamic condition and later post-operative catheterizations showed a progressive reduction of the pulmonary pressure. CONCLUSIONS: Our experience suggests that this type of heterotopic heart transplantation can be performed successfully in patients with secondary pulmonary hypertension. Particular attention should be paid to patients with restrictive cardiomyopathy and important right ventricle dysfunction, in which a complete heterotopic heart transplantation could be a better solution.


Asunto(s)
Trasplante de Corazón , Hipertensión Pulmonar/cirugía , Adolescente , Adulto , Presión Sanguínea/fisiología , Cardiomiopatía Dilatada/cirugía , Cardiomiopatía Restrictiva/cirugía , Niño , Femenino , Estudios de Seguimiento , Humanos , Hipertensión Pulmonar/complicaciones , Hipertensión Pulmonar/fisiopatología , Masculino , Resistencia Vascular/fisiología
20.
Gene ; 230(1): 81-90, 1999 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-10196477

RESUMEN

In the context of a project aimed at the identification of zinc finger proteins involved in skeletal muscle histogenesis and differentiation, we isolated a murine gene, named ZT2. The 2.44kb partial cDNA clone corresponds to the 3' region of the gene, and contains a 0.54kb open reading frame encoding four C2H2-like zinc finger domains, organized in tandem. This cDNA hybridizes with multiple transcripts (2, 4.5 and 7kb), whose expression levels vary in different tissues and at different developmental stages in the same tissue. At least in skeletal muscle we observed differences in the polyadenylation state of the transcripts at different stages of development. Moreover, ZT2 expression is correlated with cell proliferation and transformation. Sequence analysis and genetic mapping indicate that ZT2 is the homologue of ZNF125, one of the linked zinc finger encoding genes localized on human Chr 11q23. In humans, a high frequency of tumor-associated translocations is found in this chromosome region. As expected, ZT2 maps to the corresponding region on chromosome 9 in the mouse.


Asunto(s)
Proteínas de Unión al ADN/genética , Proteínas Musculares/genética , Dedos de Zinc/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Diferenciación Celular , Células Cultivadas , Mapeo Cromosómico , Clonación Molecular , Secuencia de Consenso , Proteínas de Unión al ADN/química , Ligamiento Genético , Humanos , Factores de Transcripción de Tipo Kruppel , Ratones , Datos de Secuencia Molecular , Proteínas Musculares/química , Músculo Esquelético/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Alineación de Secuencia
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