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Biomedical subjects

J P Bercovici

Publications and source records attributed to J P Bercovici.

At least 55 records · Page 3Linked to original sources
PubMed1983

[Receptiveness to sexual steroids. Physiopathological aspects].

Each hormonal signal is specifically related to a cellular receptor. However, the same receptor may bind several hormones. Oestradiol which binds to the oestrogenic receptor with a Kd of 0,1 nM, may also bind with the prostatic androgen receptor with a Kd of 3 nM. Progesterone is another example of binding pluralism as it binds not only to the progesterone receptor but also to the androgenic (anti-androgenic effect), mineralocorticoid receptors (anti-aldosterone effect) and the gluco-corticoid (anti-inflammatory effect. As different receptors may bind the same steroid, reciprocally, a given receptor may bind different steroids. What applies to natural hormones, also applies to synthetic hormones. Each new molecule has a specificity of biological action which can be predicted from pharmacological screening tests. This specificity is expressed by the affinity of relative binding to a given receptor compared with a reference steroid. In vitro studies do not take endogenic metabolism which may alter the concentration of the tested substances at the receptor site into account. The modes of receptivity to steroid hormones are complex and other factors than the receptor proteins are involved. The change in uterine blood flow induced by oestradiol cannot be explained by these mechanisms. Similarly, progesterone acts at the cell membrane level of the amphibian egg. The receptivity to sexual steroids is therefore a complex phenomenon, the first elements of which are beginning to be understood.

Androgens↗
PubMed1983

[VIP removes the inhibition of prolactin secretion induced by dopamine in patients with prolactinoma].

PRL responsitivity after Vaso-active intestinal Peptide (VIP) infusion was studied during a Dopamine (DA) infusion, in normal women and women with a prolactinoma. VIP alone (6.2 micrograms/min., 12 min.) increases PRL in normal females, but does not remove DA-induced PRL-decrease (1 microgram X kg X X min.-1). It has no effect in women with prolactinoma. In these women, PRL increases when VIP is administered at the 200th minute of DA infusion (1 microgram X kg/min.). A PRL release by VIP in women with a prolactinoma, could imply the restitution of a DA inhibitory control. The same dose of VIP does not modify PRL, when administered during a 4 microgram X kg/min. infusion of DA, in women with a prolactinoma.

Dopamine↗
PubMed1983

[Glycosylated proteins and control of the diabetic: use of continuous flow insulin pumps by the subcutaneous route].

Ten insulin-dependent diabetic patients were controlled using a portable insulin pump (Pye Dynamic MS 16). They were studied for approximately 10 weeks. The responses of fasting blood glucose, glycosylated serum proteins and glycosylated hemoglobin were studied. Glycosylated serum proteins and glycosylated hemoglobin were measured a semi-automated colorimetric method. Although the fasting blood glucose decreased by about 45%, its variability underlines its limitation as a metabolic control parameter. Glycosylated hemoglobin decreased by 9% in the first week, and 21% by the tenth week. The glycosylated serum proteins decrease was 39% in the first week and 50% by the third week. Four insulin-dependent pregnant women had a similar but less rapid, decrease in the 3 variables compared to the other 6 cases. In all ten diabetics treatment lowered the 3 variables toward normal levels when compared to 73 insulin dependent diabetic patients using the classic method of daily insulin injections. The kinetic patterns of the 3 variables confirms the usefulness of glycosylated serum proteins which respond to altered levels of control more rapidly (10 days) than glycosylated hemoglobin. This is shown both by the response to improved control in insulin-dependent diabetics and secondly by their changes after insulinoma removal. The physiopathological significance of serum protein glycosylation is at present uncertain.

Adult↗
PubMed1983

[Kinetics of prolactinemia after withdrawal of dopamine perfusion and during the administration of domperidone. Normal and hyperprolactinemic subjects (prolactinomas and suprahypophyseal lesions)].

Fifteen normal menstruating women in the early follicular phase of their menstrual cycle, fifteen patients with prolactin secreting adenomas, two patients with a suprahypophysial lesion and an hyperprolactinemia, underwent a dopamine infusion (4 micrograms/kg/mn for four hours and an orally administration of domperidone (40 mg). Prolactin rebound after the arrest of dopamine infusion and during domperidone are + 400% and + 2,300% in normal subjects. These same studies are followed by similar and reduced prolactin response in suprahypophyseal lesion and prolactinomas. Such results suggest an abnormality of central dopaminergic control and/or a primary abnormality of lactotropes in prolactinomas. In two prolactinomas the normalization of both prolactin level and prolactin responses during the same tests is in favor of a primary abnormality of adenomatous lactotrope. These data justify neuro-surgical adenomectomy.

Adenoma↗
PubMed1982

[Influence of glycemic control on peripheral nerve conduction in insulin-dependent diabetic subjects (author's transl)].

In order to better evaluate the influence of glycemic control on diabetic neuropathy, 73 diabetic patients were considered: 42 males and 31 females who had been treated with insulin during 9 years. Twenty-one subjects were examined during 2-12 months. Motor nerve conduction velocity (MCV) was measured on the external sciatic popliteus (ESP). The H reflex parameters from soleus were: latency time for H response (HL), the ratio between the maximum amplitude of the H reflex response and the M motor response: (formula: see text) was determined by a chromatographic method. The reduction of MCV, the rise in HL and the decrease of E in diabetics are more pronounced according to the duration of the disease and are significantly correlated with the rate of HbA1c (respectively MCV: r = -0.39, P less than 0.001; HL: r = 0.42, P less than 0.001; E: r = -0.37, P less than 0.01). There is a slight correlation between HbA1c level and the duration of diabetes. For the 21 diabetics observed during many months there is a very significant correlation between the slope of the evolution curves of HbA2c, MCV and HL.

Adolescent↗
PubMed1981

[Domperidone: a new pharmacodynamic agent for exploration of the hypophysis (author's transl)].

Domperidone is a peripheral antagonist of dopamine which does not cross the blood-brain barrier. It is administered orally in doses of 40 mg and consistently induces a rise in prolactin (delta + 2500 % at 90 minutes; surface under the curve 306,000) on condition that the mammotropic cells are in sufficient numbers and under central dopamine control. Adenomatous mammotrophs do not respond to domperidone (p less than 0.001 difference with controls). Three months after transphenoidal adenomectomy and correction of hyperprolactinaemia, there was no significantly change in the kinetics of prolactin response to the product. Some gonadotrophic hormone-producing adenomas exhibit paradoxical response of GH to L-dopa and domperidone, which disappears after surgical excision.

Benzimidazoles↗
PubMed1981

Leydig cell tumor with gynecomastia: hormonal effects of an estrogen-producing tumor.

A patient with a testicular interstitial cell tumor and gynecomastia is reported. The testicular tumor was capable of aromatizing 8.3% testosterone. Spermatic venous samples taken from the tumor-bearing side had marked elevations of 17 beta-estradiol (E2), progesterone, and 17-hydroxyprogesterone (170 HP). The progesterone to 17OHP and 17OHP to androstene-dione ratios suggested an enzymatic block of 17 alpha-hydroxylase and 17-20 lyase possibly secondary to locally produced E2. The E2 produced by the tumor appeared to suppress gonadotropin secretion. The plasma testosterone and gonadotropin levels rose within 7 days after the removal of tumor, and the gynecomastia began to decrease.

Adult↗
PubMed1981

[Effect of exercise on serum lipoproteins in 270 healthy men (author's transl)].

A group of two hundred seventy healthy patients aged 20 +/- 2 years endured a progressive physical program during eleven days. The caloric expense was an amount of 4,500 kcal for a ration of 4,200 kcal (+ 33%). When we compared the results of the start and end of this procedure, we found a high loss of weight (68,46 kg instead of 69,34, p less than 0,001), a total cholesterol reduction (4,33 mmol/l instead of 4,75, p less than 0,001), decrease of LDL-cholesterol (2,48 mmol/l instead of 3,15) and of triglycerides (1, 07 mmol/l instead of 0,81, p less than 0,0001); a raise of HDL cholesterol (1,06 to 1,11 mmol/l, p less than 0,01).

Adult↗
PubMed1980

[Acute post-gravidic Budd-Chiari syndrome. One case (author's transl)].

The sixth case of post-gravidic Budd-Chiari syndrome is reported. In the acute stage of the disease heparin seems to have given immediate favourable results, and the value of long-term heparin treatment is discussed. Post-mortem findings seven years after the acute episode confirmed the evolution towards a certain type of cirrhosis characterized by macroscopically and histologically heterogenous lesions and by persistent liver congestion. Portal hypertension was associated with arterialization of the portal vein and considerable dilatation of the right diaphragmatic veins. The venous drainage of the liver had undergone complex alterations: the supra-hepatic veins were affected with fairly recent incomplete ostial thrombosis, many intra-hepatic veins were reduced to a vestigial reticulum and others were the seat of recent or old re-canalized thrombosis. Cancerous transformation was found to be present in the larger hepatic nodules.

Acute Disease↗
PubMed1980

[Administration route of natural sex steroids (estradiol, progesterone, testosterone) (author's transl)].

The natural sex steroids (E2, T, P) may be used in therapeutics. Estradiol and testosterone esters (decanoate and undecanoate) may be administered orally. A local effect always follows the percutaneous application of sex steroids, and this is usually accompanied by a systemic effect. But because of the very important metabolism of progesterone by the skin, it is necessary to administer it by other routes (intravaginal, intrarectal) in order to obtain a systemic effect.

Administration, Oral↗
PubMed1980

[Contribution of motor nerve conduction velocity and Hoffmann reflex in early detection of neuropathy in diabetics. Results and correlations with duration and other long-term complications in 117 patients (author's transl)].

Motor nerve conduction velocity and H. reflex parameters were studied in 85 insulin-treated diabetics classified in groups I to VI, according to the duration of the disease, in 32 maturity-onset diabetics (groupe V) and in 92 healthy control subjects. Each diabetic subject was examined prior to testing for clinical evidence of neuropathy and also had funduscopic examination, fluorescein angiography and an estimation of renal status by serum creatinine measurement and proteinuria. Electrical parameters were significantly different in all groups of diabetics from results in the control group. Neuropathy, as judged by these electrical studies, was frequently present in the absence of clinical expression, worsened with the duration of the disease in groups I to IV and preceeded other degenerative changes of diabetes. H. reflex parameters are an earlier index of neuropathy than motor nerve conduction velocity and may be used as a monitor of diabetic neuropathy.

Adult↗