1,720,970 research outputs found
Humoral and haemodynamic interactions between clonidine and nifedipine in human essential hypertension.
No full textAcute administration of nifedipine (NIF), a calcium entry blocker (CEB), in animals reduces the hypotensive effect of clonidine (CLN), an alpha-adrenergic agonist. In order to evaluate possible negative interactions between NIF and CLN in man during chronic treatment with these drugs, 12 patients with mild to moderate uncomplicated essential hypertension received either NIF (20 mg twice daily), CLN (0.25 mg once daily), the two drugs together at the same doses, or their matched placebos for a 2-week period each. NIF (-13.5% versus placebo) and CLN (-10.2% versus placebo) decreased blood pressure significantly and when combined, blood pressure was further decreased (-17.1% versus placebo). Heart rate was increased by NIF and NIF + CLN but unchanged by CLN alone. Plasma renin activity (PRA) tended to increase with NIF, decreased with CLN (P < 0.05) and was unchanged with NIF + CLN. Plasma aldosterone did not vary during any of the phases of the trial. These results indicate that NIF and CLN do not interact negatively on blood pressure control in essential hypertensive subjects
Cryptogenic stroke
Full text linkAlthough in the last few years emerging conventional and unconventional radiological and laboratory techniques have shed light on different pathophysiologic causes of stroke, nowadays almost 25% of ischemic strokes results of undetermined etiology. Different diagnostic criteria have been developed to define cryptogenic stroke and to establish its prevalence in stroke units. Different studies tried to unravel mechanisms of cryptogenic stroke and to evaluate adequate primary and secondary preventive measures, but standardized diagnostic and therapeutic strategies are still missing. In this review we report the most relevant updated notions in cryptogenic stroke providing an overview of the definition, the recommendations for diagnostic evaluation and the updated treatment strategies for secondary prevention
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Influence of food on acute and chronic effects of captopril in essential hypertensive patients
No full textTo determine if food reduces the hemodynamic and humoral effects of captopril in patients with essential hypertension, we performed two studies. In the acute study, 15 inpatients with uncomplicated essential hypertension randomly received a single oral dose of placebo or captopril (25 mg) while fasting or after eating, or captopril (50 mg) after eating. Blood pressure and heart rate were measured every 30 min up to 4 h (and up to 10 h in six out of the 15 patients), while plasma renin activity, plasma aldosterone, and serum angiotensin-converting enzyme were measured 2 h after dosing. Compared with placebo, captopril significantly reduced mean blood pressure (p less than 0.001), serum angiotensin-converting enzyme (p less than 0.005), and aldosterone (p less than 0.001), increased plasma renin activity (p less than 0.05), and did not change heart rate; there was no difference between the fasting and the fed state. In the six patients followed up to 10 h, captopril both before and after food significantly and similarly reduced mean blood pressure up to 8 h (p less than or equal to 0.05). In the chronic study, 10 patients with uncomplicated essential hypertension, while having prolonged (3-12 months) treatment with captopril (50 mg twice a day), were asked to take captopril for 1 month 1 h before eating and for another month during or immediately after eating. The sequence was randomized, and blood pressure, heart rate, plasma renin activity, serum angiotensin-converting enzyme, and plasma aldosterone were measured at the end of each period 12 h after last dosing.
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Protective effects of flavanol-rich dark chocolate on endothelial function and wave reflection during acute hyperglycemia
No full textNitric oxide plays a pivotal role in regulating vascular tone. Different studies show endothelial function is impaired during hyperglycemia. Dark chocolate increases flow-mediated dilation in healthy and hypertensive subjects with and without glucose intolerance; however, the effect of pretreatment with dark chocolate on endothelial function and other vascular responses to hyperglycemia has not been examined. Therefore, we aimed to investigate the effects of flavanol-rich dark chocolate administration on (1) flow-mediated dilation and wave reflections; (2) blood pressure, endothelin-1 and oxidative stress, before and after oral glucose tolerance test (OGTT). Twelve healthy volunteers (5 males, 28.2 +/- 2.7 years) randomly received either 100 g/d dark chocolate or flavanol-free white chocolate for 3 days. After 7 days washout period, volunteers were switched to the other treatment. Flow-mediated dilation, stiffness index, reflection index, peak-to-peak time, blood pressure, endothelin-1 and 8-iso-PGF(2 alpha) were evaluated after each treatment phase and OGTT. Compared with white chocolate, dark chocolate ingestion improved flow-mediated dilation (P=0.03), wave reflections, endothelin-1 and 8-iso-PGF(2 alpha) (P<0.05). After white chocolate ingestion, flow-mediated dilation was reduced after OGTT from 7.88 +/- 0.68 to 6.07 +/- 0.76 (P=0.027), 6.74 +/- 0.51 (P=0.046) at 1 and 2 h after the glucose load, respectively. Similarly, after white chocolate but not after dark chocolate, wave reflections, blood pressure, and endothelin-1 and 8-iso-PGF(2 alpha) increased after OGTT. OGTT causes acute, transient impairment of endothelial function and oxidative stress, which is attenuated by flavanol-rich dark chocolate. These results suggest cocoa flavanols may contribute to vascular health by reducing the postprandial impairment of arterial function associated with the pathogenesis of atherosclerosis. (Hypertension. 2012; 60: 827-832.
Protective effects of flavanol-rich dark chocolate on endothelial function and wave reflection during acute hyperglycemia
No full textNitric oxide plays a pivotal role in regulating vascular tone. Different studies show endothelial function is impaired during hyperglycemia. Dark chocolate increases flow-mediated dilation in healthy and hypertensive subjects with and without glucose intolerance; however, the effect of pretreatment with dark chocolate on endothelial function and other vascular responses to hyperglycemia has not been examined. Therefore, we aimed to investigate the effects of flavanol-rich dark chocolate administration on (1) flow-mediated dilation and wave reflections; (2) blood pressure, endothelin-1 and oxidative stress, before and after oral glucose tolerance test (OGTT). Twelve healthy volunteers (5 males, 28.2±2.7 years) randomly received either 100 g/d dark chocolate or flavanol-free white chocolate for 3 days. After 7 days washout period, volunteers were switched to the other treatment. Flow-mediated dilation, stiffness index, reflection index, peak-to-peak time, blood pressure, endothelin-1 and 8-iso-PGF(2α) were evaluated after each treatment phase and OGTT. Compared with white chocolate, dark chocolate ingestion improved flow-mediated dilation (P=0.03), wave reflections, endothelin-1 and 8-iso-PGF(2α) (P<0.05). After white chocolate ingestion, flow-mediated dilation was reduced after OGTT from 7.88±0.68 to 6.07±0.76 (P=0.027), 6.74±0.51 (P=0.046) at 1 and 2 h after the glucose load, respectively. Similarly, after white chocolate but not after dark chocolate, wave reflections, blood pressure, and endothelin-1 and 8-iso-PGF(2α) increased after OGTT. OGTT causes acute, transient impairment of endothelial function and oxidative stress, which is attenuated by flavanol-rich dark chocolate. These results suggest cocoa flavanols may contribute to vascular health by reducing the postprandial impairment of arterial function associated with the pathogenesis of atherosclerosis
- …
