Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
1.
Neurosurg Focus ; 42(4): E8, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28366070

RESUMO

During the past 20 years, the traditional supportive treatment for stroke has been radically transformed by advances in catheter technologies and a cohort of prominent randomized controlled trials that unequivocally demonstrated significant improvement in stroke outcomes with timely endovascular intervention. However, substantial limitations to treatment remain, among the most important being timely access to care. Nonetheless, stroke care has continued its evolution by incorporating technological advances from various fields that can further reduce patients' morbidity and mortality. In this paper the authors discuss the importance of emerging technologies-mobile stroke treatment units, telemedicine, and robotically assisted angiography-as future tools for expanding access to the diagnosis and treatment of acute ischemic stroke.


Assuntos
Gerenciamento Clínico , Serviços Médicos de Emergência/métodos , Acidente Vascular Cerebral/terapia , Terapia Trombolítica/métodos , Ativador de Plasminogênio Tecidual/uso terapêutico , Isquemia Encefálica/complicações , Humanos , Acidente Vascular Cerebral/etiologia , Acidente Vascular Cerebral/mortalidade , Telemedicina , Resultado do Tratamento
2.
Semin Ultrasound CT MR ; 37(5): 466-81, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27616317

RESUMO

Vascular pathologies of the spinal cord are rare and often overlooked. This article presents clinical and imaging approaches to the diagnosis and management of spinal vascular conditions most commonly encountered in clinical practice. Ischemia, infarction, hemorrhage, aneurysms, and vascular malformations of the spine and spinal cord are discussed. Pathophysiologic mechanisms, clinical classification schemes, clinical presentations, imaging findings, and treatment modalities are considered. Recent advances in genetic and syndromic vascular pathologies of the spinal cord are also discussed. Clinically relevant spinal vascular anatomy is reviewed in detail.


Assuntos
Imageamento por Ressonância Magnética/métodos , Neuroimagem/métodos , Doenças da Medula Espinal/diagnóstico por imagem , Medula Espinal/irrigação sanguínea , Medula Espinal/diagnóstico por imagem , Doenças Vasculares/diagnóstico por imagem , Malformações Arteriovenosas/diagnóstico por imagem , Meios de Contraste , Diagnóstico Diferencial , Hemorragia/diagnóstico por imagem , Humanos , Infarto/diagnóstico por imagem
3.
J Lipid Res ; 49(7): 1395-408, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18387886

RESUMO

Diabetes mellitus, obesity, and dyslipidemia increase risk for cardiovascular disease, and expose the heart to high plasma fatty acid (FA) levels. Recent studies suggest that distinct FA species are cardiotoxic (e.g., palmitate), while others are cardioprotective (e.g., oleate), although the molecular mechanisms mediating these observations are unclear. The purpose of the present study was to investigate the differential effects of distinct FA species (varying carbon length and degree of saturation) on adult rat cardiomyocyte (ARC) gene expression. ARCs were initially challenged with 0.4 mM octanoate (8:0), palmitate (16:0), stearate (18:0), oleate (18:1), or linoleate (18:2) for 24 h. Microarray analysis revealed differential regulation of gene expression by the distinct FAs; the order regarding the number of genes whose expression was influenced by a specific FA was octanoate (1,188) > stearate (740) > palmitate (590) > oleate (83) > linoleate (65). In general, cardioprotective FAs (e.g., oleate) increased expression of genes promoting FA oxidation to a greater extent than cardiotoxic FAs (e.g., palmitate), whereas the latter induced markers of endoplasmic reticulum and oxidative stress. Subsequent RT-PCR analysis revealed distinct time- and concentration-dependent effects of these FA species, in a gene-specific manner. For example, stearate- and palmitate-mediated ucp3 induction tended to be transient (i.e., initial high induction, followed by subsequent repression), whereas oleate-mediated induction was sustained. These findings may provide insight into why diets high in unsaturated FAs (e.g., oleate) are cardioprotective, whereas diets rich in saturated FAs (e.g., palmitate) are not.


Assuntos
Envelhecimento/fisiologia , Ácidos Graxos/metabolismo , Miócitos Cardíacos/metabolismo , Transcrição Gênica/genética , Animais , Biologia Computacional , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Genoma/genética , Masculino , Ratos , Ratos Wistar , Fatores de Tempo
4.
Am J Physiol Heart Circ Physiol ; 294(2): H1036-47, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18156197

RESUMO

Virtually every mammalian cell, including cardiomyocytes, possesses an intrinsic circadian clock. The role of this transcriptionally based molecular mechanism in cardiovascular biology is poorly understood. We hypothesized that the circadian clock within the cardiomyocyte influences diurnal variations in myocardial biology. We, therefore, generated a cardiomyocyte-specific circadian clock mutant (CCM) mouse to test this hypothesis. At 12 wk of age, CCM mice exhibit normal myocardial contractile function in vivo, as assessed by echocardiography. Radiotelemetry studies reveal attenuation of heart rate diurnal variations and bradycardia in CCM mice (in the absence of conduction system abnormalities). Reduced heart rate persisted in CCM hearts perfused ex vivo in the working mode, highlighting the intrinsic nature of this phenotype. Wild-type, but not CCM, hearts exhibited a marked diurnal variation in responsiveness to an elevation in workload (80 mmHg plus 1 microM epinephrine) ex vivo, with a greater increase in cardiac power and efficiency during the dark (active) phase vs. the light (inactive) phase. Moreover, myocardial oxygen consumption and fatty acid oxidation rates were increased, whereas cardiac efficiency was decreased, in CCM hearts. These observations were associated with no alterations in mitochondrial content or structure and modest mitochondrial dysfunction in CCM hearts. Gene expression microarray analysis identified 548 and 176 genes in atria and ventricles, respectively, whose normal diurnal expression patterns were altered in CCM mice. These studies suggest that the cardiomyocyte circadian clock influences myocardial contractile function, metabolism, and gene expression.


Assuntos
Ritmo Circadiano/genética , Ritmo Circadiano/fisiologia , Expressão Gênica/fisiologia , Contração Miocárdica/fisiologia , Miocárdio/metabolismo , Miócitos Cardíacos/fisiologia , Animais , DNA/biossíntese , DNA/genética , Ecocardiografia , Eletrocardiografia , Frequência Cardíaca/fisiologia , Técnicas In Vitro , Camundongos , Mitocôndrias Cardíacas/fisiologia , Proteínas Musculares/metabolismo , Contração Miocárdica/genética , Análise de Sequência com Séries de Oligonucleotídeos , Perfusão , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais/fisiologia , Telemetria
5.
J Biol Chem ; 278(51): 51100-7, 2003 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-14527950

RESUMO

Members of the FE65 family of adaptor proteins, FE65, FE65L1, and FE65L2, bind the C-terminal region of the amyloid precursor protein (APP). Overexpression of FE65 and FE65L1 was previously reported to increase the levels of alpha-secretase-derived APP (APPs alpha). Increased beta-amyloid (A beta) generation was also observed in cells showing the FE65-dependent increase in APPs alpha. To understand the mechanism for the observed increase in both A beta and APPs alpha given that alpha-secretase cleavage of a single APP molecule precludes A beta generation, we examined the effects of FE65L1 overexpression on APP C-terminal fragments (APP CTFs). Our data show that FE65L1 potentiates gamma-secretase processing of APP CTFs, including the amyloidogenic CTF C99, accounting for the ability of FE65L1 to increase generation of APP C-terminal domain and A beta 40. The FE65L1 modulation of these processing events requires binding of FE65L1 to APP and APP CTFs and is not because of a direct effect on gamma-secretase activity, because Notch intracellular domain generation is not altered by FE65L1. Furthermore, enhanced APP CTF processing can be detected in early endosome vesicles but not in endoplasmic reticulum or Golgi membranes, suggesting that the effects of FE65L1 occur at or near the plasma membrane. Finally, although FE65L1 increases APP C-terminal domain production, it does not mediate the APP-dependent transcriptional activation observed with FE65.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal , Peptídeos beta-Amiloides/biossíntese , Precursor de Proteína beta-Amiloide/biossíntese , Proteínas de Transporte/fisiologia , Sequência de Aminoácidos , Secretases da Proteína Precursora do Amiloide , Precursor de Proteína beta-Amiloide/metabolismo , Ácido Aspártico Endopeptidases , Proteínas de Transporte/metabolismo , Linhagem Celular Tumoral , Endopeptidases/metabolismo , Endossomos/metabolismo , Humanos , Proteínas de Membrana/biossíntese , Organelas/metabolismo , Ligação Proteica , Processamento de Proteína Pós-Traducional , Receptores Notch
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA