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Biomedical subjects

C Valori

Publications and source records attributed to C Valori.

At least 19 recordsLinked to original sources

[Atrial natriuretic peptide, left ventricular mass and renin-angiotensin-aldosterone system in essential arterial hypertension of a mild or moderate degree].

OBJECTIVE: The relationship between plasma atrial natriuretic peptide (ANP), renin-angiotensin-aldosterone system and left ventricular mass in essential hypertension was assessed. PATIENTS AND METHODS: Immunoreactive ANP in 10 normal subjects and 20 untreated patients with mild to moderate essential hypertension was compared with echocardiographic measurement of cardiac size, function and blood pressure. Venous plasma concentrations of ANP were also studied in relation to urinary sodium and potassium excretion, as well as the renin-angiotensin-aldosterone system. RESULTS: Plasma ANP was higher in hypertensive patients (25.3 +/- 13.3 pg/ml; p = 0.003) than normotensive subjects (11.1 +/- 2.7 pg/ml). In hypertensive patients, plasma ANP was inversely related to plasma renin activity (PRA) (r = -0.6; p = 0.009). No relationship was found between ANP and blood pressure, nor between the indices of left ventricular mass and function or urinary electrolytes. CONCLUSIONS: This study showed that circulating ANP is, in average, significantly increased in hypertensive patients, consistent with previous reports. Our data do not support a direct link between left ventricular mass and increased plasma ANP levels in hypertensive patients. Whether the inverse relationship between ANP and PRA in this pathologic state is a direct one or merely a secondary association has not been clearly established.

Adult

[Primary hyperparathyroidism with prevalent neuro-muscular manifestations].

A case of primary hyperparathyroidism with prevalent neuromuscular symptoms is described. Clinical, diagnostic and therapeutic implications are emphasized. Particular attention must involve a full clinical examination, electromyographic data and neuromuscular biopsy to make differentiation from primary myopathy or denervation pathology. Some similarity of electromyographic data with those observed in botulism and myastenia gravis should also be taken in mind. Hypercalcemia could play a pathological role in conditioning abnormalities of nervous impulse conduction at the level of neuromuscular junction. Another possible interference might be related to a direct effect of parathormone and hypophosphataemia on nervous impulse conduction. "Glandular hyperplasia", as observed in this case at istologic examination, rises some problems as far as the prognosis is concerned.

Female

Absence of effects of ketanserin on renal prostacyclin and thromboxane A2 in essential hypertension.

The anti-hypertensive effect of ketanserin, a new antagonist of 5-HT2-serotonergic receptors, was evaluated in 10 patients with uncomplicated essential hypertension. At the end of 2 weeks of placebo wash-out and following 2 and 4 weeks of treatment with ketanserin (20 mg twice daily), blood pressure and heart rate were measured both in the supine and standing position. In addition, before and at the end of treatment, plasma renin activity (PRA), plasma concentration of aldosterone and the nocturnal urinary excretion of 6-keto-PGF1 alpha and TXB2, the two metabolites that largely reflect the renal synthesis of prostacyclin and thromboxane, respectively, were determined. The study was carried out in a metabolic ward where the intake of sodium was adjusted to 100-120 mmol day-1. Ketanserin significantly reduced blood pressure both in the supine and standing position with no significant change of heart rate. The treatment did not produce any variation of PRA, aldosterone, urinary excretion of 6-keto-PGF1 alpha or TXB2. These results indicate that ketanserin reduces blood pressure without interfering with the renin-angiotensin-aldosterone system or the renal synthesis of prostacyclin and thromboxane.

6-Ketoprostaglandin F1 alpha

[Transluminal percutaneous angioplasty in renovascular hypertension caused by monolateral fibromuscular dysplasia].

The authors, following recent observation of two cases of renovascular hypertension, one related to single right renal artery stenosis and the other to fibromuscular dysplasia of the left renal artery, examine the value of the Captopril-Test and treatment with Percutaneous Transluminal Angioplasty (PTA), in the diagnosis and therapy of this form of hypertension. According to the latest experience, reported in the literature, the Captopril-Test yields valid information as regards the dependence of hypertension on the renin-angiotensin system, while PTA represents the primary procedure in the treatment of renovascular hypertension when some conditions are satisfied as in our cases.

Adult

[Effects of ketanserin on arterial pressure at rest and during physical exercise in essential arterial hypertension].

The antihypertensive effect of ketanserin, a recent 5-hydroxytryptamine (5-HT) antagonist, which acts on the 5-HT2-subtype receptor, was evaluated in 10 patients of both sexes (age range 35-69 years) with mild to moderate essential hypertension. Blood pressure and heart rate were measured at rest, in supine and standing position at the end of two weeks of placebo washout and after 2, 4 and 8 weeks of treatment with ketanserin 20 mg twice daily as monotherapy, while the changes of blood pressure and heart rate during static (hand-grip) and dynamic (bicycle ergometer) exercise were evaluated at the end of placebo and of the fourth week of therapy. The treatment induced a highly significant reduction of supine and standing systolic and diastolic blood pressure during rest, without any significant change in heart rate. During dynamic exercise, the increase in systolic and diastolic blood pressure and heart rate was not blunted by ketanserin, while the drug reduced systolic blood pressure and heart rate increase, during static exercise, with no change of diastolic blood pressure. From these data it may be concluded that ketanserin lowers blood pressure in essential hypertension without any interference with cardiovascular reflexes related to standing or dynamic exercise, and reduces the increase of systolic blood pressure and heart rate during static exercise with favourable interference on myocardial oxygen consumption. This sparing effect on myocardial oxygen demand is particularly relevant in hypertensive patients with asymptomatic coronary disease engaged in normal daily physical activity which includes many forms of static exercise.

Adult

[Comparison of the efficacy of captopril and enalapril in single doses in the treatment of arterial hypertension. Evaluation by means of non-invasive ambulatory monitoring].

The study was designed to compare the efficacy of captopril and enalapril, both orally active inhibitors of angiotensin converting enzyme, in the treatment of primary hypertension when administered in a single daily dose. After placebo washout for two weeks, 20 hypertensive patients (I-II class, according to WHO), were admitted to active treatment, in a randomized sequence, with captopril (50 mg) and enalapril (20 mg) once a day in the morning (8 a.m.). Supine and erect blood pressure and heart rate were measured weekly, 24 hours after drug administration by using a mercury standard sphygmomanometer. In all patients ambulatory noninvasive blood pressure monitoring was performed after 4 weeks of treatment. The data confirmed the efficacy of both drugs in lowering blood pressure. However, while the antihypertensive effect of enalapril was prolonged throughout 24 hours, captopril was effective only for about 22 hours, a period longer than previously suggested on the basis of serum ACE inhibition, but not sufficient to cover the whole day. Therefore, if captopril therapy has to be used in a single daily dose an attempt should be made using an increased dosage or by employing the drug in some retarded pharmaceutical form. The need to prolong the antihypertensive effect of captopril to 24 hours is based on the clinical experience according to which the smaller the number of tablets to be taken the better the compliance. This is particularly true for cases of asymptomatic hypertension which nevertheless require lifelong therapy.

Administration, Oral

[Effects of calcium antagonists on pancreatic endocrine secretion].

The influence of Verapamil, a calcium antagonist, on circulating levels of glucose, insulin and glucagon has been evaluated in 5 normal subjects and in 5 patients with non insulin-dependent diabetes (NIDDM). An oral glucose tolerance test was performed both in basal conditions and during intravenous infusion of the drug (5 mg/h). Administration of Verapamil didn't induce any significant change on the three parameters. The small decrease of glycemia in patients affected by NIDDM and treated with Verapamil was not related to reduction of glucagonemia.

Adult

Age and responses to isometric exercise in hypertension: possible predictors of the antihypertensive effect of diuretics and beta-blockers.

In a multicenter, randomized, double-blind study, 108 hypertensive patients were treated with either chlorthalidone 25 mg or slow-release metoprolol 200 mg both given once daily over 4 weeks. Blood pressure and heart rate at rest and at the peak of an isometric exercise test (30% of maximal voluntary contraction for 3 min) were recorded at random and at the end of the study. Both treatments induced a significant (p less than 0.01) blood pressure reduction at rest and at the peak exercise, 50.0% of patients on chlorthalidone and 59.2% on metoprolol, respectively, having a lying diastolic blood pressure less than 95 mmHg. A weak but significant (p less than 0.001) positive correlation was found between age and change in systolic and diastolic blood pressure after chlorthalidone. Such a relationship was absent in the metoprolol group, where a significant (p less than 0.01) positive correlation was found between diastolic pressure rise from rest to the peak exercise at randomization, and the reduction in resting diastolic pressure at the end of the study. Treatments were well tolerated, only a decrease (p less than 0.05) in serum potassium (from 4.4 to 4.0 mEq/l) in the chlorthalidone group was observed. Results suggest that age may influence the antihypertensive response to chlorthalidone, while diastolic pressure rise in isometric exercise may predict the degree of pressure response to sustained beta-adrenergic blockade with metoprolol.

Adrenergic beta-Antagonists

Macrolide antibiotics and serum theophylline levels in relation to the severity of respiratory impairment: a comparison between the effects of erythromycin and josamycin.

Ten patients with exacerbated chronic asthmatic bronchitis, subdivided into two groups on the basis of respiratory failure, were treated with theophylline-ethylendiamine administered by continuous venous infusion (0.7 mg/kg/hr over a period of 132 hrs). The aim of the study was the evaluation of serum theophylline levels during administration of erythromycin or josamycin (500 mg q.i.d. orally for 48) hours). An increase of theophylline levels was registered during erythromycin treatment in the group of patients with greater impairment of the respiratory function, while in the other group no significant change was observed. During josamycin treatment serum theophylline concentrations did not show any increase in both groups and, moreover, a significant reduction (p less than 0.05) was observed in the more seriously ill patients.

Aged

A fixed combination of oxprenolol slow-release and chlorthalidone once daily in treatment of mild to moderate hypertension.

In a multicenter, single-blind, interpatient study, 103 outpatients with mild to moderate hypertension were given, after 2 weeks of placebo wash-out, 160 mg oxprenolol slow-release in fixed combination with chlorthalidone (20 mg per tablet) (SROC 160) once daily or conventional oxprenolol (80 mg) in fixed combination with chlorthalidone (10 mg per tablet) (COC 80) twice daily for 8 weeks. Throughout the study 22 of 51 patients on SROC 160 and 24 of 51 on COC 80 received 1 tablet once daily and, respectively, 1 tablet twice daily. The remaining patients of both groups double the corresponding dosage after the first 4 weeks. Systolic and diastolic blood pressure decreased on both treatments without and difference observed between the groups. Diastolic blood pressure normalization was achieved in both groups in the same number of patients (35). Minor side effects occurred on both treatments: only one patient on SROC 160 interrupted the study due to severe dizziness and fatigue. The advantages are discussed as regards patient's compliance with administration of fixed combination SROC 160 once daily in treatment of mild to moderate hypertension.

Adult

Effect of oxprenolol on catecholamines and plasma renin activity: acute response to frusemide in hypertensive patients.

1. Catecholamine plasma concentrations and urinary excretion were measured together with plasma renin activity in ten patients with essential hypertension and in five normal control subjects before and after a frusemide challenge. 2. The same procedure was repeated in the same subjects 3--4 days later after pretreatment with oxprenolol. 3. Noradrenaline plasma concentrations and urinary excretion increased significantly after frusemide in all cases, returning to normal values at 30 and 60 min. Adrenaline plasma concentrations and urinary excretion were unchanged. 4. Plasma renin activity increased significantly in seven patients with hypertension and normal renin basal values, remaining unchanged in three hypertensive patients with low-renin basal values. 5. Oxprenolol suppressed the response of noradrenaline and plasma renin activity to frusemide in all cases.

Adult