972 resultados para ARTERIAL STIFFNESS


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Children conceived by assisted reproductive technologies (ART) display a level of vascular dysfunction similar to that seen in children of mothers with preeclamspia. The long-term consequences of ART-associated vascular disorders are unknown and difficult to investigate in healthy children. Here, we found that vasculature from mice generated by ART display endothelial dysfunction and increased stiffness, which translated into arterial hypertension in vivo. Progeny of male ART mice also exhibited vascular dysfunction, suggesting underlying epigenetic modifications. ART mice had altered methylation at the promoter of the gene encoding eNOS in the aorta, which correlated with decreased vascular eNOS expression and NO synthesis. Administration of a deacetylase inhibitor to ART mice normalized vascular gene methylation and function and resulted in progeny without vascular dysfunction. The induction of ART-associated vascular and epigenetic alterations appeared to be related to the embryo environment; these alterations were possibly facilitated by the hormonally stimulated ovulation accompanying ART. Finally, ART mice challenged with a high-fat diet had roughly a 25% shorter life span compared with control animals. This study highlights the potential of ART to induce vascular dysfunction and shorten life span and suggests that epigenetic alterations contribute to these problems.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

BACKGROUND: The limitations of the medical management of symptomatic intracranial arterial stenosis encourage the development of new therapeutic strategies such as intracranial stenting. OBJECTIVE: To report and analyze the results of a series of 42 patients treated with 3 different endovascular techniques: isolated angioplasty, balloon-expandable coronary stents, and the Wingspan self-expandable intracranial stent system. METHODS: Forty-two patients presenting with symptomatic intracranial arterial stenosis were treated with one of these techniques. Computed tomography angiography was performed 6 months after the procedure, and the clinical neurological statuses were categorized using the modified Rankin Scale and the National Institutes of Health Stroke Scale. RESULTS: A total of 42 lesions were treated: 9 with isolated angioplasty, 14 with balloon-expandable coronary stents, and 19 with Wingspan self-expandable intracranial stents. The mean patient age was 62.9 years, and the mean arterial diameter stenosis was 73.9%. Technical success was achieved in 97.6% of the patients. The overall incidence of procedural complications was 21.4%, and the postoperative permanent morbidity/mortality rate was 7.1%. There were 3 cases of in-stent thrombosis (1 fatal) and 5 cases of asymptomatic restenosis (11.9%), 3 in the isolated angioplasty group and 2 in the Wingspan self-expandable intracranial stent group (mean follow-up 20.4 months). The rate of restenosis was higher in the angioplasty group (33%) than in the coronary (0%) and Wingspan stent (10.5%) groups. CONCLUSION: Endovascular treatment of symptomatic intracranial stenosis has significant overall morbidity and mortality rates. Nevertheless, the very critical natural history of severe refractory lesions and the relatively favorable postoperative evolution suggest that it should be considered the first alternative strategy in cases in which medical therapy has failed.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Rehabilitation programs represent an important and valuable tool for patients suffering various diseases. Supervised exercise programs for patients with peripheral arterial diseases have been shown to be efficacious in ameliorating walking performances and quality of life of such patients. With this regards the angiology service of the CHUV in Lausanne has established a multidisciplinary supervised program of vascular rehabilitation. This article describes organisation and characteristics of such a program.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Today two largely new approaches are available for the treatment of clinical hypertension. First, captopril, an orally active angiotensin converting enzyme inhibitor, makes possible chronic blockade of the renin-angiotensin system. This compound, given alone or in combination with a diuretic, normalizes the blood pressure of most hypertensive patients. Unfortunately, because captopril may induce serious adverse effects the use of this inhibitor must be restricted to patients with high blood pressure refractory to conventional antihypertensive drugs. Second, compounds such as verapamil and nifedipine are capable of producing a marked vasodilating effect by inhibiting the entry of calcium into the vascular smooth muscle cells. However, the role of calcium channel blockers in the treatment of hypertensive disease awaits more precise definition.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

BACKGROUND AND AIMS: Liver stiffness is increasingly used in the non-invasive evaluation of chronic liver diseases. Liver stiffness correlates with hepatic venous pressure gradient (HVPG) in patients with cirrhosis and holds prognostic value in this population. Hence, accuracy in its measurement is needed. Several factors independent of fibrosis influence liver stiffness, but there is insufficient information on whether meal ingestion modifies liver stiffness in cirrhosis. We investigated the changes in liver stiffness occurring after the ingestion of a liquid standard test meal in this population. METHODS: In 19 patients with cirrhosis and esophageal varices (9 alcoholic, 9 HCV-related, 1 NASH; Child score 6.9±1.8), liver stiffness (transient elastography), portal blood flow (PBF) and hepatic artery blood flow (HABF) (Doppler-Ultrasound) were measured before and 30 minutes after receiving a standard mixed liquid meal. In 10 the HVPG changes were also measured. RESULTS: Post-prandial hyperemia was accompanied by a marked increase in liver stiffness (+27±33%; p<0.0001). Changes in liver stiffness did not correlate with PBF changes, but directly correlated with HABF changes (r = 0.658; p = 0.002). After the meal, those patients showing a decrease in HABF (n = 13) had a less marked increase of liver stiffness as compared to patients in whom HABF increased (n = 6; +12±21% vs. +62±29%,p<0.0001). As expected, post-prandial hyperemia was associated with an increase in HVPG (n = 10; +26±13%, p = 0.003), but changes in liver stiffness did not correlate with HVPG changes. CONCLUSIONS: Liver stiffness increases markedly after a liquid test meal in patients with cirrhosis, suggesting that its measurement should be performed in standardized fasting conditions. The hepatic artery buffer response appears an important factor modulating postprandial changes of liver stiffness. The post-prandial increase in HVPG cannot be predicted by changes in liver stiffness.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Promazine hydrochloride was injected accidentally in the antecubital artery of a 42-year-old woman, resulting in severe ischemia of the second and third fingers of her right hand which lasted for four days before she was hospitalized. Vasodilation by combining axillary plexus block and intravenous sodium nitroprusside did not improve ischemia and local thrombolysis was performed using recombinant tissue-type plasminogen activator (50 mg over 8 hours), resulting in normalization of digital pressure in one of the two affected fingers. The outcome was favourable and amputation could be avoided.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

La Hipertensión Arterial (HTA) es uno de los principales factores de riesgo de morbilidad y mortalidad cardíaca y cerebrovascular, que afecta mundialmente, por lo que conlleva a un problema de salud pública universal. Es por ello que, el JNC7 recomienda una serie de actividades de autocuidado (AC), que se dividen en el tratamiento farmacológico y no-farmacológico, en el que deberá intervenir el personal sanitario, entre ellos, enfermería, para lograr el control de la enfermedad y evitar complicaciones.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

PURPOSE: To optimize and preliminarily evaluate a three-dimensional (3D) radial balanced steady-state free precession (bSSFP) arterial spin labeled (ASL) sequence for nonenhanced MR angiography (MRA) of the extracranial carotid arteries. MATERIALS AND METHODS: The carotid arteries of 13 healthy subjects and 2 patients were imaged on a 1.5 Tesla MRI system using an undersampled 3D radial bSSFP sequence providing a scan time of ∼4 min and 1 mm(3) isotropic resolution. A hybridized scheme that combined pseudocontinuous and pulsed ASL was used to maximize arterial coverage. The impact of a post label delay period, the sequence repetition time, and radiofrequency (RF) energy configuration of pseudocontinuous labeling on the display of the carotid arteries was assessed with contrast-to-noise ratio (CNR) measurements. Faster, higher undersampled 2 and 1 min scans were tested. RESULTS: Using hybridized ASL MRA and a 3D radial bSSFP trajectory, arterial CNR was maximized with a post label delay of 0.2 s, repetition times ≥ 2.5 s (P < 0.05), and by eliminating RF energy during the pseudocontinuous control phase (P < 0.001). With higher levels of undersampling, the carotid arteries were displayed in ≤ 2 min. CONCLUSION: Nonenhanced MRA using hybridized ASL with a 3D radial bSSFP trajectory can display long lengths of the carotid arteries with 1 mm(3) isotropic resolution. J. Magn. Reson. Imaging 2015;41:1150-1156. © 2014 Wiley Periodicals, Inc.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

BACKGROUND AND OBJECTIVES: Neonatal arterial ischemic stroke (NAIS) is associated with considerable lifetime burdens such as cerebral palsy, epilepsy, and cognitive impairment. Prospective epidemiologic studies that include outcome assessments are scarce. This study aimed to provide information on the epidemiology, clinical manifestations, infarct characteristics, associated clinical variables, treatment strategies, and outcomes of NAIS in a prospective, population-based cohort of Swiss children. METHODS: This prospective study evaluated the epidemiology, clinical manifestations, vascular territories, associated clinical variables, and treatment of all full-term neonates diagnosed with NAIS and born in Switzerland between 2000 and 2010. Follow-up was performed 2 years (mean 23.3 months, SD 4.3 months) after birth. RESULTS: One hundred neonates (67 boys) had a diagnosis of NAIS. The NAIS incidence in Switzerland during this time was 13 (95% confidence interval [CI], 11-17) per 100 000 live births. Seizures were the most common symptom (95%). Eighty-one percent had unilateral (80% left-sided) and 19% had bilateral lesions. Risk factors included maternal risk conditions (32%), birth complications (68%), and neonatal comorbidities (54%). Antithrombotic and antiplatelet therapy use was low (17%). No serious side effects were reported. Two years after birth, 39% were diagnosed with cerebral palsy and 31% had delayed mental performance. CONCLUSIONS: NAIS in Switzerland shows a similar incidence as other population-based studies. About one-third of patients developed cerebral palsy or showed delayed mental performance 2 years after birth, and children with normal mental performance may still develop deficits later in life.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

ABSTRACT Dual-trap optical tweezers are often used in high-resolution measurements in single-molecule biophysics. Such measurements can be hindered by the presence of extraneous noise sources, the most prominent of which is the coupling of fluctuations along different spatial directions, which may affect any optical tweezers setup. In this article, we analyze, both from the theoretical and the experimental points of view, the most common source for these couplings in dual-trap optical-tweezers setups: the misalignment of traps and tether. We give criteria to distinguish different kinds of misalignment, to estimate their quantitative relevance and to include them in the data analysis. The experimental data is obtained in a, to our knowledge, novel dual-trap optical-tweezers setup that directly measures forces. In the case in which misalignment is negligible, we provide a method to measure the stiffness of traps and tether based on variance analysis. This method can be seen as a calibration technique valid beyond the linear trap region. Our analysis is then employed to measure the persistence length of dsDNA tethers of three different lengths spanning two orders of magnitude. The effective persistence length of such tethers is shown to decrease with the contour length, in accordance with previous studies.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

PURPOSE OF REVIEW: To provide an overview of available evidence of the potential role of epigenetics in the pathogenesis of hypertension and vascular dysfunction. RECENT FINDINGS: Arterial hypertension is a highly heritable condition. Surprisingly, however, genetic variants only explain a tiny fraction of the phenotypic variation and the term 'missing heritability' has been coined to describe this phenomenon. Recent evidence suggests that phenotypic alteration that is unrelated to changes in DNA sequence (thereby escaping detection by classic genetic methodology) offers a potential explanation. Here, we present some basic information on epigenetics and review recent work consistent with the hypothesis of epigenetically induced arterial hypertension. SUMMARY: New technologies that enable the rigorous assessment of epigenetic changes and their phenotypic consequences may provide the basis for explaining the missing heritability of arterial hypertension and offer new possibilities for treatment and/or prevention.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Insulinomas ocultos são tumores não detectáveis aos exames convencionais. O estímulo superseletivo arterial com cálcio e coleta venosa hepática (EACV) é um exame que pode ser utilizado para localizar o segmento pancreático acometido pelo tumor. Relatamos o caso de uma paciente com insulinoma oculto detectado por meio do EACV. Além disso, são discutidos aspectos técnicos da realização do exame.