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1.
J Card Fail ; 30(3): 425-435, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37678704

RESUMO

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.


Assuntos
Insuficiência Cardíaca , Nefropatias , Disfunção Ventricular Esquerda , Humanos , Aminobutiratos/efeitos adversos , Antagonistas de Receptores de Angiotensina , Biomarcadores , Compostos de Bifenilo , Combinação de Medicamentos , Volume Sistólico , Tetrazóis/efeitos adversos , Resultado do Tratamento , Valsartana , Disfunção Ventricular Esquerda/tratamento farmacológico
2.
Vascul Pharmacol ; 148: 107140, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36563732

RESUMO

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.


Assuntos
Insuficiência Cardíaca , Humanos , Nitroprussiato/efeitos adversos , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/tratamento farmacológico , Prognóstico
3.
J Arrhythm ; 37(2): 407-413, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33821178

RESUMO

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.
Artigo em Inglês | MEDLINE | ID: mdl-32534694

RESUMO

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.


Assuntos
Infecções Bacterianas/diagnóstico , Ventrículos do Coração/diagnóstico por imagem , Imagem Cinética por Ressonância Magnética/métodos , Miocardite/diagnóstico , Volume Sistólico/fisiologia , Função Ventricular Esquerda/fisiologia , Doença Aguda , Adulto , Infecções Bacterianas/epidemiologia , Infecções Bacterianas/fisiopatologia , Eletrocardiografia , Feminino , Ventrículos do Coração/fisiopatologia , Humanos , Incidência , Itália/epidemiologia , Masculino , Pessoa de Meia-Idade , Miocardite/epidemiologia , Miocardite/fisiopatologia , Estudos Retrospectivos
5.
Scand J Med Sci Sports ; 27(11): 1411-1416, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27747933

RESUMO

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.


Assuntos
Septos Cardíacos/patologia , Hipertensão/fisiopatologia , Miocárdio/patologia , Aptidão Física , Adulto , Atletas , Ecocardiografia , Teste de Esforço , Feminino , Coração/diagnóstico por imagem , Septos Cardíacos/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
7.
Thromb Haemost ; 114(2): 423-31, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26017898

RESUMO

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.


Assuntos
Substituição de Medicamentos/efeitos adversos , Procedimentos Cirúrgicos Eletivos , Cardiopatias/mortalidade , Hemorragia/induzido quimicamente , Heparina de Baixo Peso Molecular/efeitos adversos , Complicações Pós-Operatórias/epidemiologia , Pré-Medicação/efeitos adversos , Stents , Acidente Vascular Cerebral/epidemiologia , Síndrome Coronariana Aguda/epidemiologia , Síndrome Coronariana Aguda/etiologia , Idoso , Aspirina/administração & dosagem , Comorbidade , Doença das Coronárias/complicações , Doença das Coronárias/cirurgia , Reestenose Coronária/epidemiologia , Reestenose Coronária/etiologia , Feminino , Cardiopatias/etiologia , Hemorragia/epidemiologia , Heparina de Baixo Peso Molecular/uso terapêutico , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/epidemiologia , Infarto do Miocárdio/etiologia , Intervenção Coronária Percutânea , Inibidores da Agregação Plaquetária/administração & dosagem , Complicações Pós-Operatórias/induzido quimicamente , Complicações Pós-Operatórias/tratamento farmacológico , Pontuação de Propensão , Estudos Retrospectivos , Fatores de Risco , Acidente Vascular Cerebral/etiologia , Trombofilia/tratamento farmacológico , Trombofilia/etiologia , Resultado do Tratamento
10.
Abdom Imaging ; 32(6): 775-83, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17151893

RESUMO

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.


Assuntos
Imageamento por Ressonância Magnética/métodos , Prolapso de Órgão Pélvico/diagnóstico , Feminino , Humanos , Diafragma da Pelve
11.
J Cell Physiol ; 207(2): 379-88, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16419034

RESUMO

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.


Assuntos
Calcineurina/farmacologia , Isoenzimas/metabolismo , Fibras Musculares de Contração Lenta/metabolismo , Mioblastos/metabolismo , Proteína Quinase C/metabolismo , Transporte Ativo do Núcleo Celular/efeitos dos fármacos , Animais , Calcineurina/genética , Carbazóis/farmacologia , Linhagem Celular , Inibidores Enzimáticos/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Inibidores de Histona Desacetilases , Histona Desacetilases/genética , Histona Desacetilases/metabolismo , Ácidos Hidroxâmicos/farmacologia , Indóis/farmacologia , Isoenzimas/antagonistas & inibidores , Isoenzimas/genética , Fatores de Transcrição MEF2 , Camundongos , Fibras Musculares de Contração Lenta/efeitos dos fármacos , Mutação , Mioblastos/citologia , Mioblastos/efeitos dos fármacos , Fatores de Regulação Miogênica/genética , Mioglobina/genética , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo , Proteína Quinase C/antagonistas & inibidores , Proteína Quinase C/genética , Proteína Quinase C-theta , Proteínas de Ligação a RNA/genética , Ratos , Transativadores/genética , Fatores de Transcrição/genética , Transfecção , Troponina I/genética
12.
J Cell Physiol ; 196(1): 89-97, 2003 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12767044

RESUMO

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.


Assuntos
Modelos Animais de Doenças , Genes Dominantes/genética , Resistência à Insulina , Isoenzimas/genética , Isoenzimas/metabolismo , Músculo Esquelético/enzimologia , Obesidade , Proteína Quinase C/genética , Proteína Quinase C/metabolismo , Animais , Glucose/metabolismo , Insulina/farmacologia , Resistência à Insulina/genética , Camundongos , Camundongos Transgênicos , Mutação , Obesidade/genética , Fenótipo , Proteína Quinase C-theta , Transdução de Sinais/efeitos dos fármacos
13.
J Am Coll Cardiol ; 38(5): 1277-82, 2001 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-11691495

RESUMO

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.


Assuntos
Diástole , Insuficiência Cardíaca/fisiopatologia , Sístole , Distribuição por Idade , Idoso , Progressão da Doença , Medicina Baseada em Evidências , Insuficiência Cardíaca/complicações , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/epidemiologia , Humanos , Incidência , Pessoa de Meia-Idade , Prevalência , Prognóstico , Projetos de Pesquisa/normas , Viés de Seleção , Volume Sistólico , Análise de Sobrevida , Estados Unidos/epidemiologia
14.
Eur J Heart Fail ; 3(2): 257-60, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11246065

RESUMO

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.


Assuntos
Fármacos Cardiovasculares/administração & dosagem , Comparação Transcultural , Insuficiência Cardíaca/tratamento farmacológico , Equipe de Assistência ao Paciente , Antagonistas Adrenérgicos beta/administração & dosagem , Adulto , Idoso , Inibidores da Enzima Conversora de Angiotensina/administração & dosagem , Doença Crônica , Ecocardiografia , Feminino , Insuficiência Cardíaca/diagnóstico , Humanos , Itália , Masculino , Pessoa de Meia-Idade
15.
J Heart Valve Dis ; 10(1): 72-7, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11206771

RESUMO

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.


Assuntos
Ecocardiografia Transesofagiana , Endocardite Bacteriana/cirurgia , Insuficiência da Valva Mitral/cirurgia , Doença Aguda , Adulto , Idoso , Bioprótese , Cordas Tendinosas/diagnóstico por imagem , Cordas Tendinosas/cirurgia , Endocardite Bacteriana/diagnóstico por imagem , Feminino , Implante de Prótese de Valva Cardíaca , Humanos , Masculino , Pessoa de Meia-Idade , Insuficiência da Valva Mitral/diagnóstico por imagem , Medição de Risco , Ruptura Espontânea
16.
Hernia ; 5(3): 124-8, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11759796

RESUMO

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.


Assuntos
Hérnia Ventral/cirurgia , Complicações Pós-Operatórias/cirurgia , Próteses e Implantes , Telas Cirúrgicas , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Hérnia Ventral/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/etiologia , Peritonite/etiologia , Complicações Pós-Operatórias/patologia , Infecções Cutâneas Estafilocócicas/etiologia , Staphylococcus aureus/isolamento & purificação , Telas Cirúrgicas/microbiologia
18.
FASEB J ; 14(9): 1147-58, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10834937

RESUMO

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.


Assuntos
Comunicação Autócrina/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Músculo Esquelético/citologia , Rabdomiossarcoma/patologia , Fator de Crescimento Transformador beta/farmacologia , Animais , Aprotinina/farmacologia , Divisão Celular/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Humanos , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , Mutação/genética , Cadeias Pesadas de Miosina/metabolismo , Pepstatinas/farmacologia , Plasminogênio/metabolismo , Inativadores de Plasminogênio/metabolismo , Precursores de Proteínas/genética , Precursores de Proteínas/metabolismo , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Proteínas Serina-Treonina Quinases , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptor do Fator de Crescimento Transformador beta Tipo II , Receptores de Fatores de Crescimento Transformadores beta/genética , Receptores de Fatores de Crescimento Transformadores beta/metabolismo , Rabdomiossarcoma/metabolismo , Acetato de Tetradecanoilforbol/farmacologia , Transfecção , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta/metabolismo , Células Tumorais Cultivadas , Ativador de Plasminogênio Tipo Uroquinase/antagonistas & inibidores , Ativador de Plasminogênio Tipo Uroquinase/metabolismo
19.
G Ital Cardiol ; 29(8): 918-24, 1999 Aug.
Artigo em Italiano | MEDLINE | ID: mdl-10488455

RESUMO

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.


Assuntos
Transplante de Coração , Hipertensão Pulmonar/cirurgia , Adolescente , Adulto , Pressão Sanguínea/fisiologia , Cardiomiopatia Dilatada/cirurgia , Cardiomiopatia Restritiva/cirurgia , Criança , Feminino , Seguimentos , Humanos , Hipertensão Pulmonar/complicações , Hipertensão Pulmonar/fisiopatologia , Masculino , Resistência Vascular/fisiologia
20.
J Am Coll Cardiol ; 33(5): 1182-8, 1999 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10193714

RESUMO

OBJECTIVES: The study assessed changes in left ventricular systolic and diastolic function after pericardiectomy in patients with constrictive pericarditis and correlated postoperative Doppler echocardiographic findings with clinical status. BACKGROUND: Despite the efficacy of pericardiectomy, some patients with constrictive pericarditis fail to improve postoperatively. Data on serial evaluation of systolic and diastolic function after pericardiectomy and its relation to clinical status are not available. METHODS: From 1985 to 1995, a total of 58 patients with constrictive pericarditis underwent pericardiectomy and had at least one follow-up Doppler echocardiographic study with a respirometer: 23 patients had one examination within 3 months postoperatively, 19 had a study within 3 months and another one more than 3 months postoperatively, and 16 had one study more than 3 months postoperatively. RESULTS: In the early postoperative period, diastolic function was normal in 17 patients (40.5%), restrictive in 17 (40.5%), and constrictive in 8 (19%). Among 19 patients who had serial Doppler echocardiography, in 2 patients with restrictive physiology and 5 with constrictive physiology the results had become normal, and 1 patient who had had constrictive physiology had restrictive findings. In late follow-up, left ventricular end-diastolic diameter increased compared with preoperative measurement (p = 0.0009). Diastolic filling pattern at late follow-up was normal in 20 patients (57%), restrictive in 12 (34%) and constrictive in 3 (9%). There was a significant relationship between diastolic filling patterns and symptomatic status (chi2 = 20.9, p < 0.0001). Patients with persistent abnormal diastolic filling on Doppler echocardiography had had symptoms for a longer time preoperatively than did patients with normal diastolic physiology (p = 0.0471). CONCLUSIONS: Diastolic filling characteristics remain abnormal in a substantial number of patients with constrictive pericarditis after pericardiectomy. These abnormalities may resolve gradually but can persist. Diastolic filling abnormalities after pericardiectomy correlate well with clinical symptoms and tend to occur in patients who have had symptoms longer preoperatively. This finding supports the recommendation that pericardiectomy be performed promptly in symptomatic patients with constrictive pericarditis.


Assuntos
Pericardiectomia , Pericardite Constritiva/fisiopatologia , Função Ventricular Esquerda , Adolescente , Adulto , Idoso , Diástole , Ecocardiografia Doppler , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Pericardite Constritiva/cirurgia , Período Pós-Operatório , Estudos Retrospectivos , Sístole , Resultado do Tratamento , Função Ventricular Esquerda/fisiologia
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