Eduardo Arantes Nogueira

Blood pressure circadian rhythm and endothelial function in heavy smokers: acute effects of transdermal nicotine.

Nicotine replacement therapy appears to be safe when used by healthy patients to aid in smoking cessation; however, the immediate acute effects of nicotine replacement therapy on the circadian rhythm of blood pressure (BP) and endothelial function in heavy smokers are not well understood. Twenty‐six heavy smokers were requested to stop smoking for 48 hours. BP and heart rate were recorded over 48 hours by ambulatory BP monitoring, with beat‐to‐beat changes being monitored for the first 10 hours by a noninvasive finger device. The reactivity of the brachial artery was evaluated using flow‐mediated dilation immediately after smoking cessation, before the application of a 21‐mg nicotine patch or placebo patch, and 24 hours after patch placement. Transdermal nicotine caused a mild but significant elevation in BP in the early morning in 21 of 26 volunteers. The decrease in nocturnal BP was attenuated in patients with the nicotine patch compared with the placebo patch; this was associated with impaired endothelium‐dependent vasodilation.

Aldosterone Escape With Diuretic or Angiotensin‐Converting Enzyme Inhibitor/Angiotensin II Receptor Blocker Combination Therapy in Patients With Mild to Moderate Hypertension

Renin‐angiotensin‐aldosterone system (RAAS) hyperactivity is implicated in the development of hypertension and progressive damage in target organs. Chronic inhibition of the RAAS or use of thiazide‐type diuretics may trigger an aldosterone escape. The aim of this study was to assess this phenomenon in hypertensive patients treated with thiazide‐type diuretics (hydrochlorothiazide [HCTZ]) or single or double blockade of the RAAS (irbesartan [IRBE], quinapril [QUIN], and IRBE+QUIN). Blood pressure levels were obtained by 24‐hour ambulatory blood pressure monitoring. Plasma renin activity and aldosterone levels were determined by immunoradiometric assay. Blood pressure level was normalized in the 4 treatment groups; the HCTZ and IRBE+QUIN groups showed an increased plasma aldosterone level after 12 weeks (9.1 ±2.2 to 14.1 ±1.4 and 6.9±1.9 to 12.9±2.3 ng/dL, respectively; P<.05), whereas plasma renin activity was increased only in the HCTZ group (0.9 ±0.2‐1.7 ±0.2 ng/mL/h; P<.05). The increase in plasma aldosterone level after 12 weeks of HCTZ and IRBE+QUIN therapy suggests early aldosterone escape.

Endothelial Vascular Function in Hypertensive Patients After Renin—Angiotensin System Blockad

It is unclear whether single and combined pharmacologic inhibition of the renin‐angiotensin‐aldosterone system have similar effects on endothelial function and blood pressure (BP). The authors evaluated 63 hypertensive patients divided into 4 groups (hydrochlorothiazide 25 mg/d; irbesartan [IRBE] 150 mg/d; quinapril [QUIN] 20 mg/d; or IRBE 150 mg/d + QUIN 20 mg/d) and 25 healthy normotensive subjects (normal) followed for 12 weeks. Endothelium‐dependent dysfunction measured as flow‐mediated dilation at Weeks 0 and 12 were: normal, 11.5%±2.4% vs 13.5%±2.0%; hydrochlorothiazide, 7.3%±2.0% vs 12.8%±3.1%; QUIN, 7.2%±2.8% vs 13.2%±2.1%; IRBE, 7.1%±2.8% vs 13.0%±2.9%; and IRBE + QUIN, 7.5%±1.9% vs 12.8%±3.0%. Nitroglycerin‐mediated responses were: normal, 26.0%±1.9% vs 24.0%±2.5%; hydrochlorothiazide, 17.0%±2.2% vs 18.3%±2.6%; QUIN, 17.8%±3.2% vs 23.4%±3.0%; IRBE, 16.8%±3.6% vs 24.7%±2.0%; and IRBE + QUIN, 17.3%±3.0% vs 25.1%±2.5%. Antihypertensive therapy restored BP to normal and improved the endothelium‐dependent and ‐independent dysfunction after renin‐angiotensin‐aldosterone system blockade. In a further finding, the combined effect of angiotensin‐converting enzyme inhibition and angiotensin II type 1 receptor blockade was not superior to the action of either of these treatments separately.

Artéria septal perfurante anômala com origem na artéria coronária direita

The interventricular septum is the most densely vascularized portion of the heart, containing important elements of the cardiac conduction system and providing mechanical support for both right and left ventricular function. The diagnosis and understanding of anomalies in coronary circulation are important when surgical or percutaneous myocardial revascularization is required. We report the case of a patient with an anomalous septal perforator artery arising from the proximal portion of the right coronary artery.

Modification of the nonlinear optical, dielectric, and structural properties of p-nitroaniline and 2-methyl-4-nitroaniline crystals through recrystallization under a strong dc electric field

Crystals of para-nitroaniline were grown from solution while subjected to a strong dc electric field of 2 X 105 V/m. This resulted in a modification of the unit cell lattice parameters and space group with respect to crystal grown in the absence of an electric field. The modified crystal are capable of generating a second harmonic signal and poses a significantly lower dielectric permittivity.

Second harmonic generation and symmetry of SrS2O6. 4 H2O

We show that although the crystalline structure of Strontium Dithionate Tetrahydrate can be well described in either P64 and P31 space groups (or respectively, P62 and P32) and electro-optic measurements have indicated the 32 point group, optical second harmonic measurements performed on an oriented crystal are only compatible with point group 3.

Insuficiência cardíaca de alto débito devida a fístula coronária

A 45 year-old woman complaining of heart failure symptoms (New York Heart Association--class III) and a non typical thoracic pain was submitted to a transthoracic echocardiogram which showed a very dilated coronary artery and a fistula to the right atrium. The angiograms confirmed the same findings. She underwent open heart surgery which confirmed the diagnosis. Fistula ligation was then undertaken. She remains symptom-free three years after the operation.