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Biomedical subjects

F Elkik

Publications and source records attributed to F Elkik.

36 records · Page 2Linked to original sources
PubMed1985

Renal effects of calcium blockade by tiapamil in normal and hypertensive subjects.

The acute hypotensive and renal effects of the calcium antagonist tiapamil, a verapamil derivative, were studied in nine normal and 13 essential hypertensive subjects undergoing water diuresis. Tiapamil decreased mean arterial pressure slightly in normotensive subjects and more markedly in hypertensive patients (-6 +/- 1 versus -10 +/- 2%). The effective renal plasma flow (ERPF) and glomerular filtration rate (GFR) were unaffected in both groups. A striking natriuresis was observed selectively in the hypertensive group (+344 +/- 84 versus +42 +/- 22 mmol/min) and was associated with an increase in the calculated fractional distal delivery of sodium and uric acid excretion rate. Plasma aldosterone concentration decreased moderately and to the same extent in both groups. In conclusion, tiapamil induced a marked natriuresis in essential hypertensive patients, despite a decrease in blood pressure, and in the absence of renal vasodilatation; this may suggest the existence in essential hypertension of a calcium-linked abnormality in the renal proximal tubular handling of sodium.

Adult↗
PubMed1985

[Contraception in the hypertensive woman using a vaginal ring delivering estradiol and norgestrel].

A long term prospective study of contraceptive vaginal rings (CVR) that deliver estradiol and D-Norgestrel was conducted in 12 hypertensive women. Blood pressure was measured five times by an oscillometric automatic device during two control cycles, at the 1st, 2nd, 4th, 6th and 9th to 12th cycle of CVR use, and again after a one month recovery period. No significant change in blood pressure was noted during CVR usage and this method of contraception appeared safe in hypertensive women. Plasma renin substrate and plasma antithrombin III were non affected by the treatment. These observations are in marked contrast with the dramatic increase and decrease in these proteins that are respectively observed during oral estroprogestative contraception; and confirm the utility of a way of hormone administration that bypass the liver. The significant decrease in sex binding protein, HDL cholesterol, phospholipids and triglycerides that were observed under CVR treatment could be interpreted as reflecting the androgenic potency of D-Norgestrel.

Contraceptive Agents, Female↗
PubMed1984

Renal segmental infarction: a cause of reversible malignant hypertension.

Five cases of accelerated or malignant hypertension which occurred in young adults within a few weeks of renal segmental infarction are reported here. Such infarction appears to give rise to a form of renovascular hypertension, the severity and sudden onset of which distinguishes it from renal fibrodysplasia, which is commonly observed in this age group. In three cases hypertension was corrected by nephrectomy. In two cases several months medical treatment was associated with remission of hypertension without surgery. It is therefore suggested that hypertension due to renal infarction, unlike that caused by fibromuscular dysplasia, may be managed by prolonged medical treatment.

Adult↗
PubMed1984

Effect of a new calcium antagonist, tiapamil, in hypertension of the elderly.

The antihypertensive effect of a single oral dose of tiapamil (450 mg) and placebo were compared in a single blind randomized cross-over study in 10 71-86 year old hypertensive patients. Blood pressure (BP) and heart rate (HR) were recorded every 15 min for 12 h by an automatic device. Tiapamil led to a decrease in mean daytime systolic (SBP) and diastolic (DBP) BP from 171 +/- 12/98 +/- 10 mm Hg to 159 +/- 11/90 +/- 9 mm Hg (P less than 0.001) without significant variation in HR. Thereafter patients received tiapamil 450 twice daily; by the seventh day of treatment mean daytime SBP and DBP were 155 +/- 13/85 +/- 14 mm Hg (P less than 0.001 vs placebo). The hourly mean values of SBP recorded for 8/12 h (first tiapamil day) and 10/12 h (seventh tiapamil day) were significantly lower than the corresponding values after placebo. We conclude that tiapamil in the elderly exerts a sustained antihypertensive effect lasting 12 h or more, with only minor variations in HR. This effect predominates on systolic pressure and is significant from the first dose.

Aged↗
PubMed1982

Effects of percutaneous estradiol and conjugated estrogens on the level of plasma proteins and triglycerides in postmenopausal women.

Percutaneous administration of estradiol (E2) is a new substitutive treatment for postmenopausal women. In order to compare hepatic action of percutaneous E2 with that of conjugated estrogens, 18 postmenopausal women were allocated at random to receive one of these two types of natural estrogens for 21 days. Eight patients (group I) received conjugated estrogens orally, 1.25 mg daily. Ten patients (group II) were told to apply percutaneous E2 ointment, 5 gm (i.e., 3 mg of E2), each evening on the abdominal skin. E2, estrone (E1), follicle-stimulating hormone (FSH), and luteinizing hormone (LH), and several markers of estrogen action were evaluated before and after treatment. Both types of treatment were biologically effective, as indicated by the decrease in plasma gonadotropins and the increase in estrogen levels. However, conjugated estrogens produced a greater increase in E1 than in E2; hence, the E2/E1 ratio was 0.57 in group I, whereas it was approximately 1 in group II. Plasma renin substrate increased significantly (by 180%) in group I but not in group II. In the same way, conjugated estrogens produced a modest (12%) but significant decrease in antithrombin III, whereas there was no variation with percutaneous E2. Sex steroid-binding protein was the most sensitive parameter for the hepatic action of estrogen, and increased by 18.66% with percutaneous E2 and by 150% with conjugated estrogens. Plasma triglycerides tended to increase in group I and to decrease in group II, but not significantly. Therefore, percutaneous administration of of E2, in contrast to conjugated estrogens, can produce plasma levels of estrogens closer to those observed in the follicular phase and less alterations in protein synthesis. This lesser toxicity may be explained partially by the route of administration, since with percutaneous administration of E2, the steroid bypasses the liver.

Administration, Oral↗
PubMed1982

17 alpha-hydroxylase deficiency syndrome associated with bilateral streak gonads and impaired development of Müllerian ducts derivatives. Report of a case.

We report severe 17 alpha-hydroxylase deficiency in a 17 year-old black girl with 46,XX genotype. The diagnosis was suspected because of primary amenorrhoea, absence of sexual maturation, hypertension and hypokalaemia with renal potassium wasting. Endocrine investigation revealed low basal levels of all steroid hormones which require 17 alpha-hydroxylation for biosynthesis (i.e. glucocorticoids, androgens and oestrogens). No increase in their basal levels was seen following adrenal stimulation, indicating a severe block. Plasma concentrations of ACTH, FSH and LH were elevated as were progesterone, 11-deoxycorticosterone and corticosterone. Plasma renin activity was suppressed and aldosterone levels were very low. After 4 months of glucocorticoid replacement therapy, aldosterone was still low, even though the suppression was otherwise effective. Our case is unusual because bilateral streak gonads and impaired development of Müllerian ducts derivatives were also present. To our knowledge, a similar case has never been reported before.

Adolescent↗
PubMed1981

[The renin-angiotensin system and its inhibition (author's transl)].

The recent development of several inhibitors of the renin-angiotensin system has perfected our knowledge of the part played by this system in the control of physiological and pathological arterial pressure. Peptides inhibiting angiotensin II, such as Sar1, Ala8 angiotensin II, block the peripheral effects of angiotensin on vascular renal and adrenal receptors. Inhibition of the conversion enzyme, notably with captopril, prevents the formation of angiotensin II from angiotensin I and also results in accumulation of a vasodilator and natriuretic peptide: bradykinin. Finally, it is now possible to inhibit more specifically the reaction of renin with its substrate, angiotensinogen, by using pepstatin or its derivatives, or peptide analogues of the substrate. The use of these inhibitors, especially captopril (so far the most studied), has made it clear that renin plays a part in experimental and human essential hypertension and participates in the control of arterial blood pressure in subjects with normal sodium intake.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1981

[Effectiveness of captopril in severe hypertension (author's transl)].

Fifteen patients with severe essential or renal hypertension were treated with captopril. In thirteen, a single oral dose of 1 mg/kg produced a mean fall of 20.7 +/- 16.42 mmHg (18%) in mean arterial pressure (MAP) without concomitant increase in heart rate. The fall was significant at 20 minutes and maximum at 90 minutes on average. It correlated closely with the initial plasma renin activity (PRA) (r = 0.96) and with the increase in PRA under treatment (r = 0.75). After an 8-day treatment with captopril alone in increasing dosage (mean: 453 +/- 140 mg/day), the fall in MAP still was 20.3% and correlated with that observed with a single dose. Blood pressure returned to normal levels (MAP Less Than 110 mmHg) in seven of these patients. Twelve patients were treated for a mean period of 36 days and all had normal blood pressure at the end of that period. However, seven had required addition of frusemide to the treatment. A moderate increase in serum creatinine was observed in 7 cases, but there were no other adverse reactions. Captopril alone or combined with diuretics proved to be a very effective drug for the treatment of hypertension, particularly in patients with high initial PRA.

Adolescent↗
PubMed1980

[The role of progesterone and progestins in hydroelectrolytic metabolism (author's transl)].

The role of progesterone and progestins in hydroelectrolytic metabolism have been compared. The mechanism of progesterone natriuretic action was discussed from clinical and biological data and from the recent data of the competitive action of progesterone for the mineralocorticoid receptor. However the lack of potassium retention cannot be completely explained by the balance of two characteristics of progesterone: the first being the catabolic action leading to a liberation of tissular potassium and the second, the anti-mineralocorticoid action. On the other hand synthetic progestins either derived from 17 hydroxyprogesterone of from nortestosterone exhibit a sodium retention action. Moreover some of these molecules exert an estrogenic effect leading to increase in angiotensinogene and renin activity. This effect has to be kept in mind as far as blood pressure variation is concerned. Thus, it is of great importance to find new progestins able to reproduce the natriuretic action of natural progesterone.

Animals↗
PubMed1980

Angiotensin and adrenal steroidogenesis: study of 21-hydroxylase-deficient congenital adrenal hyperplasia.

The effects of angiotensin have been studied in four adult patients with the simple virilizing form of congenital adrenal hyperplasia due to 21-hydroxylase deficiency. They were treated with hydrocortisone (25 mg/day) throughout this investigation. Plasma ACTH was normal in three cases, and androstenedione was normal in all cases. However, urinary pregnanetriol, plasma 17-hydroxyprogesterone (17 OHP), aldosterone, and renin activity was increased. The patients were then submitted to three protocols: sodium depletion (10 meq Na/day) for 5 days, sodium repletion (200 meq Na/day) for 5 days, and angiotensin infusion (sufficient to maintain a pressor response) for 60 min. Urinary pregnanetriol, plasma 17 OHP, and androstenedione levels increased in all patients after sodium depletion and decreased after sodium repletion. Plasma ACTH levels were not modified by changes in the sodium balance. Furthermore, angiotensin infusion increased aldosterone and 17 OHP plasma concentrations without any change in the plasma ACTH level. This study shows the direct action of angiotensin on adrenal steroidogenesis, at least in 21-hydroxylase deficiency. It confirms that even in the simple virilizing form, combined treatment with glucocorticoids and mineralocorticoids helps to normalize plasma 17 OHP levels.

Adrenal Glands↗
PubMedDate not supplied

[Demonstration of differences in the effect of 2 antihypertensive agents by self blood pressure measurement: comparison of trandolapril and perindopril].

In this double blind randomized study, blood pressure lowering effects and duration of action of two angiotensin converting enzyme (ACE) inhibitors were compared using home self blood pressure measurement (SBPM). After a two-week placebo run-in period, 128 hypertensive patients received during four weeks a daily morning dose of either perindopril (P) 4 mg or trandoplapril (T) 2 mg. One week of SBPM was planned at the end of both the run-in and the treatment period. Three consecutive measurements, with printed results, were requested in the morning before drug intake and in the evening. Run-in period home systolic (SBP) and diastolic (DBP) blood pressures were comparable in both groups: 149.9 +/- 14.5/97.3 +/- 8.1 mmHg in the P group (n = 63), 148.9 +/- 14.3/96.7 +/- 6.9 mmHg in the T group (n = 65). During the treatment period, evening BP was similar in the 2 groups: 139.1 +/- 14.3/89.9 +/- 9.1 mmHg in P group, 137.5 +/- 15.3/89.4 +/- 9.1 mmHg in T group (NS). On the other hand, morning BP was higher in the P group: 143.1 +/- 16.3/93.8 +/- 9.6 mmHg vs 137.4 +/- 16.7/90.3 +/- 9.7 mmHg (p < 0.05 for SBP and DBP-Student's t test). These results were confirmed by co-variance analysis after adjustment on initial BP. Due to standardized conditions of measurement, home SBPM was able to show a difference in BP lowering effects at the end of the inter-dose interval between two ACE inhibitors.

Adult↗
PubMedDate not supplied

[Risk factors of adverse effects of angiotensin-converting enzyme inhibitors. Apropos of 30,072 patients treated by trandolapril].

SUMMARY: The aim of the present study was to investigate the incidence of adverse effects and the prognostic value of various risk factors in a large population of unselected hypertensive patients treated with the ACE inhibitor trandolapril. Among the 30 072 patients investigated in this post marketing retrospective study, 1813 patients (6.0 per cent) reported an adverse effect. The five most frequent side effects were coughing (3.1 per cent), dizziness (0.7 per cent), headache (0.6 per cent) asthenia (0.5 per cent) and nausea (0.3 per cent). Intolerance risk factors for trandolapril were researched using both univariate and multivariate analysis. In the univariate analysis, a prior intolerance of an ACE inhibitor and female gender were strongly correlated with either overall intolerance or coughing. The most relevant variables for the occurrence of adverse effects, listed according to their entry order in the multivariate analysis, were: prior intolerance of ACE inhibitors (OR: 4.19, 95 per cent CI: 3.66-4.78), female gender (OR: 1.46, 95 per cent CI: 1.31-1.63), prior intolerance of other antihpertensive agents (OR: 1.27, 95 per cent CI: 1.14-1.41), smoking (OR: 0.76, 95 per cent CI: 0.66-0.87) and combination with a beta blocker (OR: 1.31, 95 per cent CI: 1.08-1.58). A prior intolerance of an ACE inhibitor appears to be a very strong predictor of coughing (OR: 6.14, 95 per cent CI: 5.24-7.19). The following variables, namely female gender (OR: 1.61, 95 per cent CI: 1.40-1.85), age 60-80 (OR: 1.25, 95 per cent CI: 1.09-1.44) and prior intolerance of other antihypertensive agents (OR: 1.20, 95 per cent CI: 1.03-2.39) appear less significant.

Aged↗