Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 82
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Artigo em Inglês | MEDLINE | ID: mdl-39392288

RESUMO

Summary: Background. Allergic rhinitis (AR) is a widespread condition. The Italian Society of Pediatric Allergology and Immunology (SIAIP) promoted an initiative to update the knowledge on AR in children and adolescents. The present survey directly addressed primary care pediatricians, thus reflecting the real-world management of AR in children and adolescents. The aim was to investigate common practice in managing AR children. Methods. A panel of experts drafted a series of questions concerning the practical management of children with AR in clinical practice. The questionnaire was administered to a large sample of primary care pediatricians (864). Results. 864 primary care pediatricians participated to the survey. Each pediatrician on average follows 94 children with AR; globally 81,231 children. More than 70% of participants follow ARIA guidelines. Accordingly, 42% of children have mild AR and 58% moderate/severe. Asthma, conjunctivitis and adenoid hypertrophy are the most common comorbidity. Most pediatricians autonomously follow their patients. The intensity of treatment (use of medication) is directly proportional to the symptom severity.  Intranasal corticosteroids are the most common medication used followed by oral antihistamines and nasal lavages (with hypertonic or isotonic solution). Up to 20% of participants prescribe the fixed association topical corticosteroids plus antihistamine. Conclusions. The present survey demonstrated that Italian primary care pediatricians accomplish ARIA guidelines and adapt treatment on the basis of the intensity of symptoms. Corticosteroids and antihistamines are the most common prescribed medications. Nasal lavages are also popular.

2.
J Biol Regul Homeost Agents ; 33(2): 593-599, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30945510

RESUMO

Gastroesophageal reflux disease (GERD) may be frequently associated with asthma in children and may affect asthma control. Proton pump inhibitors (PPI) are commonly prescribed in asthmatic children, despite uncertain efficacy on respiratory symptoms and risk of relevant adverse effects.


Assuntos
Alginatos/uso terapêutico , Asma/tratamento farmacológico , Refluxo Gastroesofágico/induzido quimicamente , Magnésio/uso terapêutico , Inibidores da Bomba de Prótons/uso terapêutico , Alginatos/efeitos adversos , Asma/complicações , Criança , Humanos , Magnésio/efeitos adversos , Inibidores da Bomba de Prótons/efeitos adversos
3.
Eur J Neurol ; 25(5): 711-717, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29359374

RESUMO

BACKGROUND AND PURPOSE: Misdiagnosis of refractory epilepsy (rE) is common and such patients experience a long diagnostic delay. Our aim was to identify key clinical/laboratory factors in order to obtain an alternative diagnosis in patients referred for rE. METHODS: Between January 2010 and December 2015, 125 consecutive patients with a diagnosis of rE were prospectively enrolled. All patients underwent a comprehensive neurological, neuropsychiatric and cardiological evaluation, and had an observation time of at least 1 year after the study entry. RESULTS: Diagnosis of rE was confirmed in 104/125 (83.2%) patients (55 women, mean age 38.8 ± 14.3 years). Thirteen/125 patients (10.4%, seven women, mean age 50.8 ± 20.9) were diagnosed with syncope, which was cardiac/cardio inhibitory in 9/13 (69%). The remaining 8/125 patients (6.4%, six women, mean age 41.2 ± 14.6 years) were diagnosed with psychogenic non-epileptic seizures. Age at onset had a high accuracy in differentiating patients with syncope from others, with the best cut-off age at 35 years and above. Abnormal brain magnetic resonance imaging (MRI) had a significant yield of about 70% in rE. A diagnostic model including age at onset and brain MRI was highly accurate in differentiating patients with syncope from others. In patients with cardiac/cardio inhibitory syncope, the point score of historical features was ≥1 and falsely favoured the diagnosis of epileptic seizures. CONCLUSIONS: This prospective cohort study identifies rE mimics who are at high risk of morbidity and mortality. rE starting in adulthood should raise a high suspicion of cardiac syncope. Brain MRI is accurate in differentiating rE from other conditions.


Assuntos
Encéfalo/diagnóstico por imagem , Epilepsia Resistente a Medicamentos/diagnóstico , Convulsões/diagnóstico , Síncope/diagnóstico , Adulto , Idade de Início , Idoso , Estudos de Coortes , Diagnóstico Tardio , Diagnóstico Diferencial , Erros de Diagnóstico , Epilepsia Resistente a Medicamentos/diagnóstico por imagem , Eletroencefalografia , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Convulsões/diagnóstico por imagem , Síncope/diagnóstico por imagem
4.
J Biol Regul Homeost Agents ; 29(2 Suppl 1): 70-2, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26634590

RESUMO

Bronchial asthma is a chronic inflammatory disease characterized by bronchial obstruction, usually reversible spontaneously or after therapy, bronchial hyperreactivity and accelerated decrease of lung function that may possibly evolve into irreversible obstruction of the respiratory tract. Bronchial provocation tests can be used in order to assess the presence and degree of bronchial hyper reactivity. The recently introduced mannitol powder inhalation indirect test seems to have an interesting and promising role, especially in childhood, because of its high diagnostic specificity, easiness of execution and best standardization. In this study the authors focused on the significance and clinical use of mannitol bronchial challenge test in asthmatic children.

5.
J Biol Regul Homeost Agents ; 29(2 Suppl 1): 80-3, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26634592

RESUMO

Probiotics are able to restore microbiome and the normal intestinal permeability, improve the immunological function of gut barrier and reduce the intestinal inflammatory response and the production of pro-inflammatory cytokine characteristics of local and systemic allergic inflammation. Clinical studies have demonstrated the efficacy of probiotics in the treatment of various clinical conditions such as atopic dermatitis and food allergies and in the primary prevention of atopy. Recent studies have shown that oral administration of certain probiotic exerts therapeutic effects in the treatment of allergic respiratory diseases such as asthma and rhinitis.

6.
Biomed Pharmacother ; 174: 116466, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38552439

RESUMO

Here, by using in vitro and ex vivo approaches, we elucidate the impairment of the hydrogen sulfide (H2S) pathway in vascular complications associated with metabolic syndrome (MetS). In the in vitro model simulating hyperlipidemic/hyperglycemic conditions, we observe significant hallmarks of endothelial dysfunction, including eNOS/NO signaling impairment, ROS overproduction, and a reduction in CSE-derived H2S. Transitioning to an ex vivo model using db/db mice, a genetic MetS model, we identify a downregulation of CBS and CSE expression in aorta, coupled with a diminished L-cysteine-induced vasorelaxation. Molecular mechanisms of eNOS/NO signaling impairment, dissected using pharmacological and molecular approaches, indicate an altered eNOS/Cav-1 ratio, along with reduced Ach- and Iso-induced vasorelaxation and increased L-NIO-induced contraction. In vivo treatment with the H2S donor Erucin ameliorates vascular dysfunction observed in db/db mice without impacting eNOS, further highlighting a specific action on smooth muscle component rather than the endothelium. Analyzing the NO signaling pathway in db/db mice aortas, reduced cGMP levels were detected, implicating a defective sGC/cGMP signaling. In vivo Erucin administration restores cGMP content. This beneficial effect involves an increased sGC activity, due to enzyme persulfidation observed in sGC overexpressed cells, coupled with PDE5 inhibition. In conclusion, our study demonstrates a pivotal role of reduced cGMP levels in impaired vasorelaxation in a murine model of MetS involving an impairment of both H2S and NO signaling. Exogenous H2S supplementation through Erucin represents a promising alternative in MetS therapy, targeting smooth muscle cells and supporting the importance of lifestyle and nutrition in managing MetS.


Assuntos
GMP Cíclico , Sulfeto de Hidrogênio , Síndrome Metabólica , Camundongos Endogâmicos C57BL , Guanilil Ciclase Solúvel , Animais , Sulfeto de Hidrogênio/metabolismo , Sulfeto de Hidrogênio/farmacologia , GMP Cíclico/metabolismo , Síndrome Metabólica/metabolismo , Camundongos , Masculino , Guanilil Ciclase Solúvel/metabolismo , Vasodilatação/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Óxido Nítrico Sintase Tipo III/metabolismo , Humanos , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/metabolismo , Óxido Nítrico/metabolismo , Aorta/efeitos dos fármacos , Aorta/metabolismo , Doenças Vasculares/metabolismo , Modelos Animais de Doenças
7.
Nat Med ; 1(6): 541-5, 1995 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-7585120

RESUMO

Proliferation of smooth muscle cells of the arterial wall in response to local injury is an important aetiologic factor of vascular proliferative disorders such as atherosclerosis and restenosis after angioplasty. Ras proteins are key transducers of mitogenic signals from membrane to nucleus in many cell types. We investigated the role of ras proteins in the vascular response to arterial injury by inactivating cellular ras of rats in which the common carotid artery was subjected to balloon injury. DNA vectors expressing ras transdominant negative mutants, which interfere with ras function, reduced neointimal formation after injury. Our results indicate a key role for ras in smooth muscle cell proliferation and show that the local delivery of transdominant negative mutants of ras in vivo might prevent some of the acute vascular injury caused by balloon injury.


Assuntos
Genes ras , Terapia Genética , Músculo Liso Vascular/efeitos dos fármacos , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Proto-Oncogênicas p21(ras)/antagonistas & inibidores , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Animais , Lesões das Artérias Carótidas , Artéria Carótida Primitiva/efeitos dos fármacos , Artéria Carótida Primitiva/patologia , Cateterismo/efeitos adversos , Divisão Celular/efeitos dos fármacos , Divisão Celular/genética , DNA Recombinante/genética , DNA Recombinante/uso terapêutico , Músculo Liso Vascular/lesões , Músculo Liso Vascular/patologia , Mutação Puntual , Proteínas Serina-Treonina Quinases/genética , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas c-raf , Proteínas Proto-Oncogênicas p21(ras)/genética , Ratos , Ratos Wistar , Proteínas Recombinantes de Fusão , Transfecção
8.
Nat Med ; 3(7): 775-9, 1997 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9212106

RESUMO

Injury of the arterial wall induces the formation of the neointima. This structure is generated by the growth of mitogenically activated smooth muscle cells of the arterial wall. The molecular mechanism underlying the formation of the neointima involves deregulated cell growth, primarily triggered by the injury of the arterial wall. The activated gene products transmitting the injury-induced mitogenic stimuli have been identified and inhibited by several means: transdominant negative expression vectors, antisense oligodeoxynucleotides, adenovirus-mediated gene transfer, antibodies and inactivating drugs. Results of our study show that local administration of 3',5'-cyclic AMP and phosphodiesterase-inhibitor drugs (aminophylline and amrinone) to rats markedly inhibits neointima formation after balloon injury in vivo and in smooth muscle cells in vitro. The growth inhibitory effect of aminophylline was completely reversed by the inhibition of cAMP-dependent protein kinase A (PKA). These findings indicate an alternative approach to the treatment of diseases associated with injury-induced cell growth of the arterial wall, as stimulation of cAMP signaling is pharmacologically feasible in the clinical setting.


Assuntos
Divisão Celular , Proteínas Quinases Dependentes de AMP Cíclico/fisiologia , Músculo Liso Vascular/citologia , Transdução de Sinais , 8-Bromo Monofosfato de Adenosina Cíclica/farmacologia , Aminofilina/farmacologia , Amrinona/farmacologia , Animais , Artérias Carótidas , Divisão Celular/efeitos dos fármacos , Divisão Celular/fisiologia , Células Cultivadas , Proteínas Quinases Dependentes de AMP Cíclico/antagonistas & inibidores , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Relação Dose-Resposta a Droga , Ativação Enzimática , Inibidores do Crescimento/farmacologia , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/lesões , Músculo Liso Vascular/metabolismo , Inibidores de Fosfodiesterase/farmacologia , Ratos , Transdução de Sinais/efeitos dos fármacos
9.
Minerva Cardioangiol ; 59(1): 17-29, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21285928

RESUMO

AIM: Atrio-ventricular anatomo-functional response to successful surgical atrial fibrillation (AF) ablation has been poorly investigated. Determinants of AF recurrence following surgical ablation are still debated. METHODS: Sixty-nine patients underwent AF ablation during major cardiac surgery. Main outcomes were clinical and echocardiographic results after monopolar and/or bipolar ablation were recorded. Secondary outcomes were freedom from AF, rehospitalization and congestive heart failure (CHF) at follow-up. Predictors of AF-recurrence were evaluated. RESULTS: Fifty-three patients (76.8%) were in sinus rhythm (SR) at 31.4±10.6 months of mean follow-up. Overall freedom from AF-recurrence was 61.4±6.6%, from hospital readmission 89.9±3.6%, from CHF 91.9±5.05%. Compared to AF-patients, SR-patients demonstrated better freedom from re-hospitalization (98.1±1.9% vs. 62.5±12.1%; P=0.0001) and CHF (94.7±5.1% vs. 77.8±13.9%; P=0.006). At follow-up SR-patients demonstrated atrial (preoperative 5.9±1.2 cm vs. follow-up 5.2±1.0; P=0.01) and ventricular reverse remodelling (preoperative LVDd 5.8±1.6cm vs. follow-up 5.0±1.3 cm; P=0.002 - preoperative LVDs 4.2±1.8 cm vs. follow-up 3.8±1.2 cm; P=0.045). E/A ratio was normal in 90.6% of SR-patients (69.6% of the total population of the study). TDI at the level of the left lateral annulus showed an improved left ventricular systole (Sm), and diastole (Em, E/Em) for SR-patients compared to AF-patients (Sm 9.30±1.66 vs. 7.81±1.41, P=0.001; Em: 10.55±1.87 vs. 7.44±0.40, P=0.001; E/Em: 0.06±0.02 vs. 0.11±0.05, P=0.0001). Preoperative atrial diameter (OR=23.9; P=0.002) and tricuspid insufficiency at follow-up (OR=3.5; P=0.008) were independent predictors of AF-recurrence. Neither etiology, nor duration of AF, nor even ablation technique influenced SR recovery (P=NS for all measurement). CONCLUSION: Radiofrequency AF ablation achieves 76.8% of SR recovery at follow-up. Maintenance of SR improves clinical, haemodynamic and echocardiographic results.


Assuntos
Fibrilação Atrial/fisiopatologia , Fibrilação Atrial/cirurgia , Ablação por Cateter , Idoso , Ablação por Cateter/métodos , Feminino , Testes de Função Cardíaca , Humanos , Masculino , Pessoa de Meia-Idade
10.
J Cardiovasc Surg (Torino) ; 49(3): 393-7, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18446127

RESUMO

Pericardial effusions often complicate the postoperative course of ascending aortic surgery. We evaluated whether an unconventional use of hemostatic fleeces (TachoSil, Nycomed; Austria), wrapped around aortic tube grafts, may reduce such complication. Twenty-nine consecutive patients undergoing button-Bentall were submitted - according to surgeon's choice - to 360 degrees wrapping of the aortic grafts with hemostatic fleeces immediately before sternal wiring (11 patients - group A) or sternal wiring without any wrapping of the prosthesis (18 patients - group B). Hospital outcome was recorded. No differences were recorded in hospital mortality and major organ morbidity. When pericardial complications were considered, group A showed lower chest drains (P=0.0001), time of chest drainage (P=0.002), pretamponade/tamponade with need for pericardiocentesis (P=0.039), predischarge echocardiographic amount of pericardial effusion (P=0.026), fever (P=0.029), need for anti-inflammatory (P=0.05) or antibiotic drugs (P=0.007), hospital stay (P=0.010) and white blood cell count (P=0.016 on postoperative day 3; P=0.014 on day 6). Wrapping of aortic tube grafts with hemostatic fleeces is effective in reducing pericardial effusion and its deleterious effects following aortic surgery.


Assuntos
Doenças da Aorta/cirurgia , Prótese Vascular , Fibrinogênio , Hemostasia Cirúrgica/instrumentação , Derrame Pericárdico/prevenção & controle , Complicações Pós-Operatórias/prevenção & controle , Trombina , Doenças da Aorta/diagnóstico por imagem , Implante de Prótese Vascular/métodos , Combinação de Medicamentos , Feminino , Humanos , Masculino , Derrame Pericárdico/diagnóstico por imagem , Complicações Pós-Operatórias/diagnóstico por imagem , Resultado do Tratamento , Ultrassonografia
11.
Annu Int Conf IEEE Eng Med Biol Soc ; 2018: 3185-3188, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30441071

RESUMO

Coronary arteries are medium-small caliber vessels, in which low shear rate values are encountered, where non-Newtonian blood effects cannot be neglected. This work aims to study a comparison between Newtonian and non-Newtonian blood behaviors in a cohort offorty-eight 3D patient-specific stenotic vessels (right (RCA), left (LAD) and circumflex (LCX) coronary artery) at different grades of stenosis. Numerical simulation was carried out by means of Computational Fluid Dynamics (CFD) Analysis to investigate the blood velocity and distribution of the shear stress indices at different times of the cardiac cycle. A statistical analysis was performed to have a prediction ofincrement or decrement ofthe various hemodynamic parameters. The results show that the non-Newtonian effects are mostly important in shear stress indices distributions.


Assuntos
Doença da Artéria Coronariana , Velocidade do Fluxo Sanguíneo , Simulação por Computador , Vasos Coronários , Hemodinâmica , Humanos , Modelos Cardiovasculares , Estresse Mecânico
12.
J Mol Biol ; 429(12): 1817-1828, 2017 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-28502794

RESUMO

MicroRNAs are key regulators of vascular smooth muscle cells (VSMCs) phenotypic switch, one of the main events responsible for bare metal in-stent restenosis after percutaneous coronary intervention. miR-125a-5p is an important modulator of differentiation, proliferation, and migration in different cell types; however, its role in VSMCs is still unknown. The aim of this study was to evaluate the role of miR-125a-5p in VSMCs phenotypic switch. Our results suggest that miR-125a-5p is highly expressed in VSMCs, but it is down-regulated after vascular injury in vivo. Its overexpression is sufficient to reduce VSMCs proliferation and migration, and it is able to promote the expression of selective VSMCs markers such as alpha smooth muscle actin, myosin heavy chain 11, and smooth muscle 22 alpha. Interestingly, miR-125a-5p directly targets ETS-1, a transcription factor implicated in cell proliferation and migration and is crucial in PDGF-BB pathway in VSMCs. Thus, miR-125a-5p in this context inhibits PDGF-BB pathway and is therefore a potential regulator of VSMCs phenotypic switch.


Assuntos
Diferenciação Celular , Movimento Celular , Proliferação de Células , Regulação da Expressão Gênica , MicroRNAs/metabolismo , Músculo Liso Vascular/fisiologia , Proteína Proto-Oncogênica c-ets-1/biossíntese , Animais , Músculo Liso Vascular/metabolismo , Ratos
13.
Circ Res ; 88(3): 319-24, 2001 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-11179200

RESUMO

cAMP-dependent protein kinase is anchored to discrete cellular compartments by a family of proteins, the A-kinase anchor proteins (AKAPs). We have investigated in vivo and in vitro the biological effects of the expression of a prototypic member of the family, AKAP75, on smooth muscle cells. In vitro expression of AKAP75 in smooth muscle cells stimulated cAMP-induced transcription, increased the levels of the cyclin-dependent kinase-2 inhibitor p27(kip1), and reduced cell proliferation. In vivo expression of exogenous AKAP75 in common carotid arteries, subjected to balloon injury, significantly increased the levels of p27(kip1) and inhibited neointimal hyperplasia. Both the effects in smooth muscle cells in vitro and in carotid arteries in vivo were specifically dependent on the amplification of cAMP-dependent protein kinase (PKA) signals by membrane-bound PKA, as indicated by selective loss of the AKAP75 biological effects in mutants defective in the PKA anchor domain or by suppression of AKAP effects by the PKA-specific protein kinase inhibitor. These data indicate that AKAP proteins selectively amplify cAMP-PKA signaling in vitro and in vivo and suggest a possible target for the inhibition of the neointimal hyperplasia after vascular injury.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal , Proteínas de Transporte/metabolismo , Proteínas de Ciclo Celular , Divisão Celular/fisiologia , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Músculo Liso Vascular/metabolismo , Proteínas Supressoras de Tumor , 8-Bromo Monofosfato de Adenosina Cíclica/farmacologia , Proteínas de Ancoragem à Quinase A , Animais , Artérias Carótidas/química , Artérias Carótidas/patologia , Proteínas de Transporte/genética , Divisão Celular/efeitos dos fármacos , Células Cultivadas , Cloranfenicol O-Acetiltransferase/efeitos dos fármacos , Cloranfenicol O-Acetiltransferase/genética , Cloranfenicol O-Acetiltransferase/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/efeitos dos fármacos , Inibidor de Quinase Dependente de Ciclina p27 , DNA/biossíntese , DNA/efeitos dos fármacos , DNA Recombinante , Técnicas de Transferência de Genes , Imuno-Histoquímica , Proteínas Associadas aos Microtúbulos/análise , Músculo Liso Vascular/citologia , Músculo Liso Vascular/efeitos dos fármacos , Plasmídeos/genética , Ratos , Ratos Wistar , Proteínas Recombinantes de Fusão/efeitos dos fármacos , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Transdução de Sinais/efeitos dos fármacos , Fatores de Tempo , Túnica Íntima/química , Túnica Íntima/patologia , Túnica Média/química , Túnica Média/patologia
15.
Circulation ; 101(6): 689-94, 2000 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-10673263

RESUMO

The use of quantitative coronary angiography, combined with Doppler and PET, has recently been directed at the study of alpha-adrenergic coronary vasomotion in humans. Confirming prior animal experiments, there is no evidence of alpha-adrenergic coronary constrictor tone at rest. Again confirming prior experiments, responses to alpha-adrenoceptor activation are augmented in the presence of coronary endothelial dysfunction and atherosclerosis, involving both alpha(1)- and alpha(2)-adrenoceptors in epicardial conduit arteries and microvessels. Such augmented alpha-adrenergic coronary constriction is observed during exercise and coronary interventions, and it is powerful enough to induce myocardial ischemia and limit myocardial function. Recent studies indicate a genetic determination of alpha(2)-adrenergic coronary constriction.


Assuntos
Vasos Coronários/fisiopatologia , Isquemia Miocárdica/fisiopatologia , Receptores Adrenérgicos alfa/fisiologia , Vasoconstrição , Humanos
16.
Circulation ; 103(24): 2980-6, 2001 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-11413090

RESUMO

BACKGROUND: The mechanisms of increased neointimal hyperplasia after coronary interventions in diabetic patients are still unknown. METHODS AND RESULTS: Glucose and insulin effects on in vitro vascular smooth muscle cell (VSMC) proliferation and migration were assessed. The effect of balloon injury on neointimal hyperplasia was studied in streptozotocin-induced diabetic rats with or without adjunct insulin therapy. To study the effect of balloon injury in nondiabetic rats with hyperinsulinemia, pancreatic islets were transplanted under the kidney capsule in normal rats. Glucose did not increase VSMC proliferation and migration in vitro. In contrast, insulin induced a significant increase in VSMC proliferation and migration in cell cultures. Furthermore, in VSMC culture, insulin increased MAPK activation. A reduction in neointimal hyperplasia was consistently documented after vascular injury in hyperglycemic streptozotocin-induced diabetic rats. Insulin therapy significantly increased neointimal hyperplasia in these rats. This effect of hyperinsulinemia was totally abolished by transfection on the arterial wall of the N17H-ras-negative mutant gene. Finally, after experimental balloon angioplasty in hyperinsulinemic nondiabetic islet-transplanted rats, a significant increase in neointimal hyperplasia was observed. CONCLUSIONS: In rats with streptozotocin-induced diabetes, balloon injury was not associated with an increase in neointimal formation. Exogenous insulin administration in diabetic rats and islet transplantation in nondiabetic rats increased both blood insulin levels and neointimal hyperplasia after balloon injury. Hyperinsulinemia through activation of the ras/MAPK pathway, rather than hyperglycemia per se, seems to be of crucial importance in determining the exaggerated neointimal hyperplasia after balloon angioplasty in diabetic animals.


Assuntos
Angioplastia com Balão , Doenças das Artérias Carótidas/patologia , Diabetes Mellitus Experimental/patologia , Hiperinsulinismo/patologia , Hiperplasia/patologia , Transplante das Ilhotas Pancreáticas , Túnica Íntima/patologia , Angioplastia com Balão/efeitos adversos , Animais , Glicemia , Doenças das Artérias Carótidas/etiologia , Doenças das Artérias Carótidas/genética , Divisão Celular/efeitos dos fármacos , Divisão Celular/genética , Movimento Celular/efeitos dos fármacos , Células Cultivadas , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/metabolismo , Modelos Animais de Doenças , Glucose/farmacologia , Hiperinsulinismo/induzido quimicamente , Hiperinsulinismo/metabolismo , Hiperplasia/etiologia , Hiperplasia/genética , Insulina/sangue , Insulina/farmacologia , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Músculo Liso Vascular/citologia , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/enzimologia , Mutagênese Sítio-Dirigida , Ratos , Ratos Endogâmicos F344 , Ratos Wistar , Transdução de Sinais/efeitos dos fármacos , Estreptozocina , Transfecção , Túnica Íntima/metabolismo , Proteínas ras/antagonistas & inibidores , Proteínas ras/genética
17.
J Am Coll Cardiol ; 35(1): 214-21, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10636283

RESUMO

OBJECTIVES: We sought to evaluate the effects of hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase inhibitors on vascular smooth muscle cell (VSMC) proliferation in vitro and neointimal formation in vivo after vascular injury. BACKGROUND: Neointimal hyperplasia after vascular injury is responsible for restenosis after arterial stenting, whereas arterial remodeling and neointimal formation are the causes of restenosis after percutaneous transluminal coronary angioplasty. METHODS: We assessed the effect of simvastatin on in vitro VSMC proliferation. To study the effects of simvastatin in vivo, balloon injury and stent deployment were performed in the common carotid artery of rats. Neointimal area was measured two weeks later in the balloon injury model and three weeks after stent deployment. RESULTS: Simvastatin markedly inhibits VSMC proliferation in vitro. In vivo, simvastatin reduced, in a dose-dependent manner, the neointimal area and the neointima-media ratio after balloon injury from 0.266 +/- 0.015 mm2 to 0.080 +/- 0.026 mm2 and from 1.271 +/- 0.074 to 0.436 +/- 0.158 (p < 0.001 vs. control rats) at the highest dose. Simvastatin also significantly reduced the neointimal formation and the neointima-media ratio after stenting from 0.508 +/- 0.035 mm2 to 0.362 +/- 0.047 mm2 (p < 0.05 vs. control rats) and from 2.000 +/- 0.136 to 1.374 +/- 0.180 (p < 0.05 vs. control rats). The vessel thrombosis rate after stent deployment was 30% in the control group and 11.1% in the treated group (p = NS). Moreover, the systemic administration of simvastatin did not affect hepatic and renal functions, blood pressure or heart rate. CONCLUSIONS: Simvastatin potently inhibits VSMC proliferation in vitro and reduces neointimal formation in a rat model of vascular injury.


Assuntos
Divisão Celular/efeitos dos fármacos , Oclusão de Enxerto Vascular/patologia , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Músculo Liso Vascular/efeitos dos fármacos , Sinvastatina/farmacologia , Stents , Túnica Íntima/efeitos dos fármacos , Animais , Divisão Celular/fisiologia , Células Cultivadas , Técnicas In Vitro , Masculino , Músculo Liso Vascular/patologia , Ratos , Ratos Wistar , Recidiva , Túnica Íntima/patologia , Túnica Média/efeitos dos fármacos , Túnica Média/patologia , Cicatrização/efeitos dos fármacos , Cicatrização/fisiologia
18.
J Am Coll Cardiol ; 10(4): 787-93, 1987 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-2958531

RESUMO

Hemodynamic and hormonal effects of two graded infusions of alpha-human-(1-28)-atrial natriuretic factor (0.5 microgram/kg prime followed by 0.05 microgram/kg per min for 20 minutes and by 0.1 microgram/kg per min for 20 minutes) were evaluated in 13 patients with mild to moderate essential hypertension. The lower dose of atrial natriuretic factor did not change significantly any of the considered variables, although it tended to reduce aortic mean blood pressure (from 132.6 +/- 5.3 to 125.5 +/- 4.6 mm Hg), cardiac index (from 3.67 +/- 0.2 to 3.54 +/- 0.18 liters/min per m2) and forearm vascular resistance (from 178.6 +/- 15 to 148.3 +/- 10 mm Hg/ml per s). The higher dose of atrial natriuretic factor significantly reduced mean aortic pressure (118.6 +/- 5 mm Hg), cardiac index (3.29 +/- 0.16 liters/min per m2) and stroke volume index (from 45.9 +/- 2.6 to 38.9 +/- 3 ml/m2) and slightly decreased pulmonary wedge pressure, whereas both total peripheral resistance and forearm vascular resistance were not modified. With this latter dose a reduction in aortic pressure was observed in all patients at the steady state, and this was associated with a fall in stroke volume index in 10 of the 13 patients and with a reduction in total peripheral resistance in only 6 patients. Heart rate and right atrial and pulmonary pressures did not change during infusion of atrial natriuretic factor. Plasma renin activity was only slightly reduced by atrial natriuretic factor, whereas plasma norepinephrine rose significantly (from 233 +/- 34 to 330 +/- 58 pg/ml).(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Fator Natriurético Atrial/farmacologia , Hemodinâmica/efeitos dos fármacos , Hipertensão/sangue , Adulto , Aldosterona/sangue , Fator Natriurético Atrial/efeitos adversos , Epinefrina/sangue , Feminino , Humanos , Hipertensão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Norepinefrina/sangue , Renina/sangue
19.
J Am Coll Cardiol ; 24(2): 399-405, 1994 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8034874

RESUMO

OBJECTIVES: This study evaluated the relation between reversible segmental left ventricular dysfunction and frequency domain measures of heart period variability in patients with coronary artery disease. BACKGROUND: Heart period variability is frequently reduced in patients with coronary artery disease. However, the mechanisms of this reduction are still unclear. METHODS: Echocardiographic left ventricular wall motion and frequency domain measures of heart period variability were evaluated in 32 patients with one-vessel coronary artery disease before and 16 to 24 days after successful percutaneous transluminal coronary angioplasty. Of these, 12 patients (Group A) had normal and 20 patients (Group B) had abnormal regional wall motion. A control group of 15 healthy subjects (Group C) underwent 24-h Holter recording twice at 2-week intervals to check for spontaneous variations. RESULTS: At baseline, low and high frequency power were lower in Group B than in Groups A and C, whereas no difference was detectable in ultra low and very low frequency and total power. After coronary angioplasty, regional wall motion and frequency domain measures of heart period variability were unchanged in Group A. In Group B the mean (+/- SD) summed segment score improved from 17.1 +/- 3.6 to 12.8 +/- 2.0 (p < 0.01), and mean low and high frequency power (logarithmic units) increased from 6.14 +/- 0.23 to 6.35 +/- 0.34 (p < 0.01) and from 5.43 +/- 0.32 to 5.68 +/- 0.52 (p < 0.01), respectively. Furthermore, low and high frequency power, lower at baseline in Group B than in the other two groups, were comparable in the three groups after coronary angioplasty. CONCLUSIONS: This study demonstrates that segmental left ventricular dysfunction is involved in determining sympathovagal imbalance in patients with one-vessel coronary artery disease; the reversal of left ventricular dysfunction by successful coronary angioplasty improves the heart period power spectrum. Thus, alterations in cardiac geometry influence the discharge of afferent sympathetic mechanoreceptors, contributing to the derangement in autonomic control of heart rate.


Assuntos
Doença das Coronárias/fisiopatologia , Frequência Cardíaca , Função Ventricular Esquerda , Vias Aferentes , Angioplastia Coronária com Balão , Estudos de Casos e Controles , Doença das Coronárias/terapia , Eletrocardiografia Ambulatorial , Feminino , Coração/inervação , Humanos , Masculino , Pessoa de Meia-Idade , Sistema Nervoso Simpático/fisiologia , Sistema Nervoso Simpático/fisiopatologia , Nervo Vago/fisiologia , Nervo Vago/fisiopatologia
20.
J Am Coll Cardiol ; 36(1): 288-93, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10898448

RESUMO

OBJECTIVES: The aims of the present study were to assess 1) the effect of 8-C1-cAMP (cyclic-3'-5'-adenosine monophosphate) on vascular smooth muscle cell (VSMC) proliferation in vitro and 2) the efficacy of systemic administration of 8-C1-cAMP on neointimal formation after balloon injury in vivo. BACKGROUND: Neointimal formation after vascular injury is responsible for restenosis after arterial stenting. Recently, 8-C1-cAMP, a cAMP analogue that induces growth arrest, has been safely administered in phase I studies in humans. METHODS: The effect of 8-C1-cAMP on cell proliferation was first assessed on SMCs in vitro. To study the effects of cAMP in vivo, balloon injury was performed in 67 rats using a 2F Fogarty balloon catheter. RESULTS: The 8-C1-cAMP markedly inhibited VSMC proliferation in vitro, reduced protein kinase A (PKA) RIalpha subunit expression, and induced PKA RIIbeta subunit expression. In addition, 8-C1-cAMP reduced, in a dose-dependent manner, neointimal area and neointima/media ratio after balloon injury. The proliferative activity, assessed by proliferating nuclear cell antigen immunostaining, revealed a reduction of proliferative activity of VSMCs in vivo in the 8-C1-cAMP group. Moreover, the systemic administration of 8-C1-cAMP did not affect renal function, blood pressure and heart rate. CONCLUSIONS: We conclude that 8-C1-cAMP potently inhibits VSMC proliferation in vitro and reduces neointima formation by balloon injury in vivo after systemic administration. These data may have a clinical relevance in designing future strategies to prevent restenosis after arterial stenting and perhaps after percutaneous transluminal coronary angioplasty.


Assuntos
8-Bromo Monofosfato de Adenosina Cíclica/análogos & derivados , Antineoplásicos/farmacologia , Músculo Liso Vascular/efeitos dos fármacos , Túnica Íntima/efeitos dos fármacos , 8-Bromo Monofosfato de Adenosina Cíclica/administração & dosagem , 8-Bromo Monofosfato de Adenosina Cíclica/farmacologia , Animais , Antineoplásicos/administração & dosagem , Aorta Torácica/lesões , Aorta Torácica/patologia , Arteriopatias Oclusivas/enzimologia , Arteriopatias Oclusivas/metabolismo , Arteriopatias Oclusivas/prevenção & controle , Pressão Sanguínea/efeitos dos fármacos , Cateterismo/efeitos adversos , Divisão Celular/efeitos dos fármacos , Células Cultivadas , Subunidade RIIbeta da Proteína Quinase Dependente de AMP Cíclico , Subunidade RIalfa da Proteína Quinase Dependente de AMP Cíclico , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Regulação para Baixo/efeitos dos fármacos , Frequência Cardíaca/efeitos dos fármacos , Injeções Intraperitoneais , Músculo Liso Vascular/citologia , Músculo Liso Vascular/enzimologia , Ratos , Ratos Wistar , Túnica Íntima/citologia , Túnica Íntima/enzimologia , Regulação para Cima/efeitos dos fármacos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA