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Biomedical subjects

B Gourmel

Publications and source records attributed to B Gourmel.

31 records · Page 2Linked to original sources

Comparison of four beta-blockers as assessed by 24-hour ECG recording.

beta-Blockers are used as if they were equivalent. With ECG recordings in 42 patients we investigated the effect on sinus heart rate of four beta-blockers given at three successive daily doses. Heart rate was dose-dependently decreased by all drugs except acebutolol, the effect of which decreased at a higher dosage. The maximal effects of metoprolol, nadolol, and propranolol were similar but the drugs differed in potency (dosage producing 50% of maximal effect, calculated from the dose-effect relationships; nadolol, 0.3 mg/day; metoprolol, 120 mg/day; propranolol, 47 mg/day). Similar relationships were found with drug plasma concentrations (concentration producing 50% of maximal effect: nadolol, 3.5 ng/ml; metoprolol, 21 ng/ml; propranolol, 36 ng/ml) and with supine or upright heart rates and blood pressures. However, the drugs were not equivalent: In addition to its greater potency, nadolol differed from propranolol and metoprolol in the slope of its dose-response curve. We conclude that beta-blockers can be compared by ECG recordings and that nadolol is different from the other beta-blockers without intrinsic sympathomimetic activity.

Acebutolol↗

Percutaneous absorption of 5 alpha-dihydrotestosterone in man. I. Plasma androgen and gonadotrophin levels in normal adult men after percutaneous administration of 5 alpha-dihydrotestosterone.

The distribution of 5 alpha-dihydrotestosterone to the blood following application of a solution of this androgen to the skin in a hydro-alcoholic gel was studied in order to evaluate the adequacy of the percutaneous route in correcting androgen deficiencies. In 14 adult men, daily percutaneous administration of 5 alpha-dihydrotestosterone (125 mg in 5 g gel) increases, on the average, 4 to 5 times its initial concentration in plasma. On the 14th day of treatment, repeated evaluations of plasma 5 alpha-dihydrotestosterone, between 2 and 21 h after final administration of gel, demonstrated the stability of diurnal 5 alpha-dihydrotestosterone levels and showed the regular distribution of the steroid from a presumably cutaneous reservoir. Plasma 5 alpha-androstane-3 alpha,17 beta-diol levels evolve parallel to those of 5 alpha-dihydrotestosterone. Plasma testosterone and luteinizing hormone, on the contrary, decrease considerably. No variation of follicle-stimulating-hormone is observed during treatment. The percutaneous absorption represents an interesting method for administration of a natural androgen in men, particularly because one avoids the deleterious effects of supra-physiological levels in the liver achieved with oral administration.

Adult↗

Physiological and pathological variations in saliva cortisol.

A radioimmunological method for measuring saliva cortisol was worked out. It includes one extraction and one radiocompetitive reaction with an anticortisol 3-CMO:BSA immunoserum. Frequent values for saliva cortisol were determined in various physiological and pathological conditions and compared to plasma cortisol values. In adult men, the mean concentrations at 8 a.m. and midnight were respectively 14.50 +/- 7.10 and 1.40 +/- 1.21 nmol/l (mean +/- SD). In untreated women, plasma and saliva cortisol levels were not significantly different from those measured in women taking estroprogestative drugs or in pregnant women. Following stimulation by synthetic beta 1-24 ACTH (Synacthen), the saliva cortisol determined 90 min after the 8 a.m. sampling rose by over 500% whereas plasma cortisol only rose by 120%. Similarly the drop in 8 a.m. cortisol, which followed midnight administration of 1 mg of dexamethasone was larger for saliva than for plasma cortisol. In patients with adrenal hyperactivity the circadian rhythm disappeared from saliva cortisol and patients with deficient adrenal activity displayed drastically reduced levels for saliva cortisol. Saliva cortisol seems thus to be more helpful to diagnosis than plasma cortisol.

Adolescent↗

Post-menopausal concentrations of plasma oestradiol, oestrone, FSH and LH and of total urinary oestradiol and oestrone after a single sublingual dose of oestradiol-17 beta.

We report the effects of sublingual absorption of a single dose (0.5 mg) of oestradiol-17 beta (E2) in 8 post-menopausal women, on plasma E2 and oestrone (E1), urine elimination of total E2 + E1 and on plasma FSH and LH. The results show that sublingual absorption of E2 occurs and that plasma concentrations of E2 obtained (between 133.2 to 320 pmol/l) in this way were higher than those obtained after percutaneous absorption of a single dose (3 mg) of E2. The ratio E1/E2 in plasma is close to that of pre-menopausal women.

Absorption↗

[Male fertility in Hodgkin's disease before and after chemotherapy (author's transl)].

Sperm examinations and/or measurements of plasma FSH, LH and testosterone were performed on 54 patients with Hodgkin's disease before and/or after 3 or 6 courses of multiagent chemotherapy (MOPP). In 24 patients without constitutional symptoms the results of fresh and frozen sperm examination were similar to those of a fertile control population. In 23 patients, pretreatment hormone levels were identical with those of controls. During the first year following completion of chemotherapy all patients had azoospermia and high FSH levels. From the second year onwards, 2 out of 16 patients had normal spermatogenesis (the wife of one of these gave birth to a healthy child), while 4 had grossly deficient spermatogenesis and 10 azoospermia. All male patients suffering from Hodgkin's disease should be asked to give sperm for freezing before chemotherapy and should be informed that spermatogenesis may be resumed from the second posttreatment year.

Adult↗

A simple radioimmunoassay of acebutolol in plasma.

Antisera against acebutolol were produced in rabbits immunized by means of this drug conjugated with bovine serum albumin. These antisera were used to develop a method of radioimmunoassay for acebutolol. The plasma radioimmunoassay, described here, requires no extraction and is very easy to perform besides being quick, specific and sensitive. As little as 2.97 X 10(-9) mol/l of acebutolol can be detected. This radioimmunoassay is suitable for assaying the large number of samples usually measured in pharmacological studies.

Acebutolol↗

Simultaneous radioimmunoassay of androstenedione, dehydroepiandrosterone and 11-beta-hydroxyandrostenedione in plasma.

A simultaneous radioimmunoassay for delta 4-androstenedione (delta 4), dehydroepiandrosterone (DHA) and 11 beta-hydroxyandrostenedione (11 beta OH delta 4) in plasma is described. This involved preparing first an anti-11 beta-hydroxyandrostenedione-3-0-carboxymethyl oxime/BSA antiserum which binds both delta 4 and 11 beta OH delta 4, and an anti-dehydrosterone-7-0-carboxymethyl oxime/BSA antiserum. A chromatographic step using celite minicolumns separates these three steroids. The method was applied to the measurement of the plasma basal values of these three androgens in control subjects. Mean concentrations (ng/ml) of delta 4, DHA and 11 beta OH delta 4 were respecstively 1.35, 6.63 and 3.13 in males; 1.35, 6.65 and 2.59 in premenopausal females; 0.46, 1.53 and 1.38 in post-menopausal females, and 0.39, 0.73 and 1.78 in children 1--6 years of age. Dynamic tests were also carried out: ACTH stimulation was found to increase delta 4, DHA and 11 beta OH delta 4. Dexamethasone had a reverse effect causing a 50% diminution in delta 4 levels, a marked decrease in DHA levels, and a 90% decrease in 11 beta OH delta 4 levels. Metyrapone test was found to produce a 223% increase in delta 4 levels, a 196% increase in DHA levels, and a decrease of more than 90% in the 11 beta OH delta 4 levels. Estroprogestative drug treatment was accompanied by a decrease of not only delta 4, but also of DHA and 11 beta OH delta 4. Preliminary clinical results concerning these steroids show a parallel increase or decrease of delta 4 and 11 beta OH delta 4 in adrenal pathology. In ovarian hyperandrogeny, delta 4 is increased and 11 beta OH delta 4 is unchanged.

Adrenocorticotropic Hormone↗

[Colorimetric micromethod for serum iodine determination].

The measurement of iodine is a widely accepted method to explore iodine disorders. The most precise estimation is the determination of the urinary iodine in 24-hour collections. Urine collection is notoriously difficult to obtain, specially in children. In these conditions, serum measurement could be a method to overcome these limitations. We describe a colorimetric method adapted on a microtiter plate, with optimized serum mineralization conditions. The method is linear to 2400 nmol/L with a detection limit of 75 nmol/L. Precision is below 10%. The method was validated against one automatic technique. We conclude that this relatively simple method could be an additional tool to explore dysthyroidism.

Adult↗

[Dried blood spot Vitamin A determination by high pressure liquid chromatography with electrochemical detection].

In tropical countries. vitamin A deficiency is one of the most important dietary deficiencies. Its monitoring usually involves analysis of retinol after venipuncture with some difficulties (disease transmission, religious belief). Sample collection on Dried Blood Spot (DBS) is less invasive and safer. Sample storage is easier. We developed a liquid chromatography method with electrochemical detection to measure DBS retinol. Retinol acetate was used as an internal standard. The method is linear up to 2.5 microM with a detection limit of 0.04 microM. Precision is below 10% and DBS retinol recovery overage is 90%. DBS retinol concentration decreased during 7 days after sampling, it is necessary to wait this delay before to determine vitamin A concentrations. In Congolese children DBS retinol measurement showed a severe vitamin A deficiency in 8% of them. This percentage is closely correlated with clinical parameters.

Chromatography, High Pressure Liquid↗