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Biomedical subjects

M Bellet

Publications and source records attributed to M Bellet.

At least 109 records · Page 6Linked to original sources

First-step treatment of mild to moderate uncomplicated essential hypertension by a new calcium antagonist: nicardipine.

Nicardipine, a new calcium antagonist, was tested in a 14-week double-blind trial including 15 outpatients with uncomplicated essential hypertension. They were randomly assigned to nicardipine (20-30 mg three times daily) or placebo as first-step treatment. When necessary but always after a minimum of 4 weeks, pindolol (15 mg/day) was combined with nicardipine or placebo. At the end of step 1 (85 +/- 6 days with nicardipine vs. 58 +/- 6 days with placebo, p less than 0.01), nicardipine induced larger drops in supine systolic and diastolic blood pressure (SBP and DBP) than the placebo (21 +/- 2.5 vs 1.4 +/- 3 mm Hg, p less than 0.001, and 13 +/- 2 vs. 3.5 +/- 1.5 mm Hg, p less than 0.001, respectively). In the nicardipine group (n = 57), 53% of patients had controlled blood pressure (SBP less than 160 mm Hg and DBP less than 95 mm Hg) versus 17% in the placebo group (n = 47), p less than 0.001. There was no significant correlation between the decrease in blood pressure and the age of patients. The most common side effects in the nicardipine group were flushes (12%), headache (8%), ankle edema (5%), and asthenia (4%). When blood pressure was not brought under control and pindolol was prescribed as the second-step treatment, the nicardipine group (n = 52) displayed larger drops in SBP and DBP than the placebo group (n = 40) (27 +/- 5 vs. 15 +/- 3 mm Hg, p less than 0.01, and 18 +/- 1 vs. 9 +/- 2 mm Hg, p less than 0.001, respectively). These results show that a calcium antagonist is useful for first-step treatment of hypertension.

Adult↗

Acute and chronic effects of a new calcium inhibitor, nicardipine, on renal hemodynamics in hypertension.

Renal hemodynamics and natriuresis were studied in 10 hypertensive patients without renal failure, 2 and 4 h after oral intake of 30 mg nicardipine; then, nicardipine was given at a dose of 30 mg three times a day and the hemodynamic study was repeated on the 6th day (2 h after the morning dose). The first dose of nicardipine produced an increase in renal blood flow (from 888 +/- 45 to 999 +/- 59 ml/min 1.73 m2, p less than 0.01) and a decrease in renal vascular resistances (from 0.16 +/- 0.01 to 0.12 +/- 0.01 arbitrary unit, p less than 0.05). Glomerular filtration rate did not change and the decrease in filtration fraction was not significant. Sodium excretion increased markedly during the first 2 h (from 0.17 +/- 0.04 to 0.29 +/- 0.06 mmol/min, p less than 0.05). On the 6th day renal vascular resistances and filtration fraction remained lowered whereas glomerular filtration rate was unchanged. Nicardipine did not produce any significant alteration in plasma renin activity and plasma aldosterone after acute or chronic administration. These results confirm the potent renal vasodilatory effect of nicardipine; glomerular filtration rate was not significantly altered whereas renal blood flow and filtration fraction returned to normal levels. An early and transient natriuretic effect was observed after the first dose of nicardipine, and body weight showed a significant decrease during the study indicating that no sodium retention was induced by nicardipine.

Adult↗

CT appearances of ossicular injuries.

Trauma of the ossicular chain is a frequent complication of temporal bone injury. Skull trauma from blows to the temporal, parietal, or occipital region (with or without fracture of the temporal bone) is the main cause of ossicular injury; other modes of injury are rare. Ossicular injury usually occurs as a dislocation, of which there are five types: incudostapedial joint separation, incudomalleolar joint separation, dislocation of the incus, dislocation of the malleoincudal complex, and stapediovestibular dislocation. Fracture of the malleus, incus, or stapes is uncommon. High-resolution computed tomography is the method of choice for evaluation of ossicular trauma. Joint separation and fracture of the stapes are seen on axial images; coronal images may aid visualization. Both axial and coronal images are needed for evaluation of a dislocated malleus or incus. Fracture of the malleus or incus is detected with axial or coronal images; reformatted images may also be useful.

Adolescent↗

Dissociated effects of nicardipine on vascular tone and insulin secretion.

Because Ca2+ antagonists may alter glucose homeostasis by blocking calcium entry into pancreatic beta-cells, this risk was evaluated for nicardipine, a new dihydropyridine derivative with vasodilatory effects. It was tested in vitro for its vascular and insulinotropic effects on isolated perfused rat pancreases. In vivo, an oral glucose tolerance test (OGTT) was conducted, and blood pressure was recorded in eight hypertensive patients with glucose intolerance who were given 90 mg/day nicardipine for 2 weeks in a single-blind placebo-controlled study. In vitro, insulin output was inhibited by 10(-4) M nicardipine but not by 10(-8) M and 10(-6) M, whereas significant changes in intrapancreatic perfusate flow indicated that vascular resistance was similarly reduced by all three concentrations. In vivo, blood pressure diminished significantly after nicardipine, but neither glucose tolerance nor insulin release was further impaired during OGTT. From these in vitro data and this short-term clinical follow-up, it is suggested that nicardipine reduces vascular tone at doses lower than those required to inhibit insulin secretion.

Adult↗