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Biomedical subjects

B Descomps

Publications and source records attributed to B Descomps.

At least 73 records · Page 4Linked to original sources
PubMed1982

[Enzymatic determination of urinary estrone and estradiol: correlations with plasma estradiol in the menstrual cycle in women].

Enzymatic determination of urine estrone and estradiol concentrations were done daily during a menstrual cycle in six female volunteers. The results were compared with plasma estradiol determined by radioimmunoassay in the same patients. The pattern of estrone and estradiol excretion in morning urine sample fairly reproduced plasma estradiol variations and a good correlation was observed (r = 0.78). The urine pattern of estrone and estradiol variation determined by the enzyme assay can be considered as a good index of oestrogen secretion. The preovulatory peak of estrone and estradiol was observed in urine the day before or the same day as the LH peak. Estrone and estradiol concentration in urine doubled the mean value of the concentration of the follicular phase several days before the LH peak giving a useful indication for prediction of ovulation.

Estradiol↗
PubMed1981

Purification and substrate characterization of a human enkephalin-degrading aminopeptidase.

A 5000-fold purification of the enzyme responsible for the rapid inactivation of enkephalin in human blood has been achieved: this enzyme cleaves the N-terminal tyrosine from enkephalin and from short peptides provided their first amino acid is aromatic. The enzyme, an enkephalin-degrading aminopeptidase (alpha-aminoacyl-peptide hydrolase, EC 3.4.11.11), requires a free amino group on the substrate and has a maximum activity around pH 8. Its appearance molecular weight is in the range of 80 000-90 000 and an apparent Michaelis constant of 0.4 mM was determined.

Aminopeptidases↗
PubMed1981

[Rapid simultaneous assay of the principalamide-type local anesthetics by gas-liquid chromatography].

This method can assay simultaneously, using 300 microliters of plasma, of the three principle local anesthetic agents used by peridural injection for post-operative anesthesia and analgesia: xylocaïne, etidocaïne, bupivacaïne. The assay method consists of three steps: (a) the addition of an internal calibrating agent (mepivacaïne). (b) defecation using trichlorocetic acid. (c) alcalinization of the supernatent (pH 11), extraction with dichloromethane and concentration at room temperature of the organic phase. (d) chromotography using an SE 30 or OV 17 impregnated column. The method is sensitive between 0.37 mumoles per l-1 (0.1 microgram . ml-1) and the coefficient for the mean deviation is 10.9% for concentration between 0.37 mumoles 1-1 and 75 mumole1-1 (0.1 microgram . ml-1 and 20 micrograms . ml-1). The correspondence of the figures recorded in this large concentration range without any change in the technique means that the kinetics of the plasma concentrations before and after peridural injection can be followed. The results obtained by gas liquid chromatography for the assay of lidocaïne were compared in 115 different plasma samples with concentrations obtained by an immuno enzymatic method ("EMIT") fitted to a centrifuge analyser. The correlation coefficient between the two methods was: (r = 0.95 with y = 0.09 x +0.25 microgram . ml-1 implying the absence of any interference and the specificity of the two methods. The columns also separate in 20 minutes the two main metabolites of lidocaïne: monoethylglycinexylidide (M.E.G.X.) and glycinexylidide (G.X.). These results demonstrate that continuous peridural injection of lidocaïne produces a high plasma concentration without any clinical toxic phenomena.

Anesthetics, Local↗
PubMed1981

[Androgen receptors in the fetus of a primate (Macaca fascicularis) : preliminary results].

Skin fibroblasts raised from Macaca fascicularis skin samples were tested for specific androgen receptors. By the 100th day of gestation male and female skin fibroblasts androgen receptors were detected. Higher levels of androgen receptors were found in sex skin fibroblasts. These preliminary results suggest that this primate could be used as a good model for the study of androgen receptors ontogenesis and regulation.

Animals↗
PubMed1981

Comparative study of the kinetics of 3-hydroxy-3-methylglutaryl coenzyme A reductase and [14C]-acetate incorporation into cholesterol in human lymphocytes stimulated by phytohemagglutinin or sterol efflux.

The time course of sterol biosynthesis was compared after two different stimulations in normal human lymphocytes: culture either in the presence of phytohemagglutinin (PHA) or in a lipid-depleted medium (i. e. a condition which produces sterol efflux). Stimulation by PHA gives rise to an acute and rapid response in 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase activity and cholesterol synthesis. The sterol efflux induction produces a slower and milder response and the delayed sterol production consists mainly of lathosterol.

Acetates↗
PubMed1980

Estradiol and progesterone receptors in human endometrium: normal and abnormal menstrual cycles and early pregnancy.

Estradiol and progesterone receptor sites (empty or filled with endogenous hormone)have been measured in the cytoplasm and nuclei of human endometrium. Receptor changes have been observed throughout the normal menstrual cycle. During the preovulatory phase the cytoplasmic estradiol receptor sites do not change while the nuclear receptor sites more than double. Cytoplasmic estradiol receptor sites decrease very early in the secretory phase, whereas the decrease in nuclear sites occurs later. Cytoplasmic progesterone receptor sites more than double during the preovulatory phase and show a large decrease immediately after ovulation, when the concentration of nuclear receptor is at its highest. Thus the total cellular concentrations of both estradiol and progesterone receptors are lowest in the late secretory phase. It was found that they are positively correlated with the concentration of plasma estradiol only during the proliferative phase. The concentration of cytoplasmic progesterone receptor is negatively correlated with 17 beta-hydroxysteroid oxidoreductase activity during the secretory phase. In anovulatory cycles the concentrations of estradiol and progesterone receptors are high, similar to those of the late proliferative phase. "luteal insufficiency" is characterized by a very low concentration of estradiol receptor. Early pregnancy endometrium (8 to 10 weeks' gestation) is characterized by a large concentration of progesterone receptor, exceeding those of any period of the menstrual cycle.

Anovulation↗
PubMed1980

Coupling of delta 5,3-ketosteroid isomerase to human placental lactogen with intermolecular disulfide bond formation. Use of this conjugate for a sensitive enzyme immunoassay.

An immunoassay for human placental lactogen (HPL) has been developed with the use of hormone labelled with delta 5,3-ketosteroid isomerase. The enzyme is coupled to the antigen via an intermolecular disulfide interchange reaction. HPL-enzyme conjugates are prepared in high yield and purified by affinity chromatography. An enzyme immunoassay using these hormone-enzyme derivatives is compared with radioimmunoassay for determination of HPL in serum.

Animals↗
PubMed1980

Affinity chromatography: a tool for enzyme immunoassay.

Affinity chromatography has been widely used for enzyme purification and for the preparation of antigen-enzyme conjugates. Most enzyme immunoassay use immunoadsorbent (specific or double insolubilized antibodies) which makes automation difficult as centrifugation and washing steps are necessary. We propose affinity chromatography for rapid separation of antigen-enzyme bound to antibodies from free conjugate and its application in enzyme immunoassay. We describe enzyme immunoassays for human placental lactogen and progesterone which use delta 5,3-ketosteroid isomerase as marker and depend upon retention by specific absorbent of enzyme conjugate not bound to antibodies.

Adsorption↗
PubMed1980

[Decrease in BSP clearance during epidural anesthesia at a constant flow rate. Clinical implications].

The fractional clearance K1 of bromsulphthalein was measured in twelve surgical patients at an interval of a least 48 hours. The first measurement was performed pre-operatively and the second postoperatively 24 hours after the operation, whilst the patients were receiving analgesia by the epidural injection of lignocaine at a constant flow rate. Between the two determinations there was a fall in BSP clearance of 25 +/- 11 p. 100 (range: -8 and -40 p. 100) P less than or equal to 0.0001. The clinical implications are discussed on the basis of concrete examples.

Adult↗
PubMed1980

[Comparison of postoperative blood levels of prolactin and somatotropin after two methods of anesthesia].

Prolactin and somatotrophin were measured during the postoperative period in two series of 15 patients after gynaecological surgery. Samples were collected for four days at the same times during the 24 hours period. The anesthetic given in the first group was a neuroleptanalgesia of dextromoramide-droperidol type followed by postoperative analagesia using a noramidopyrine compound. In the second group, epidural anaesthesia was given, followed postoperatively by the injection of lidocain at constant rate interrupted between the final two samples. In the neuroleptanalgesia group, from a basal levels of 11 micrograms.l-1, prolactin rose to 22 micrograms.l-1 on the evening after surgery (p less than 0.001) to subsequently stay on a plateau between 6 and 8 micrograms.l-1 (p less than 0.025 to p less than 0.005). From a basal level of 2.8 micrograms.l-1, somatotrophin rose to 9 micrograms.l-1 (p less than 0.05) then fell progressively from 7.5 to 2 micrograms.l-1 (NS on D1, D2, D3). In the epidural group, from a basal level of 13.5 micrograms.l-1, prolactin rose to 23 micrograms.l-1 on the evening after surgery (NS) to fall sharply on D1 to 5.6 micrograms.l-1 (p less than 0.01) and then follow a plateau on D2 and D3 of the order of 11 to 12 micrograms.l-1 (NS). From a basal level of 1.9 micrograms.l-1, somatotrophin rose to 10 micrograms.l-1 (p less than 0.001) to fall again to 4.5 micrograms.l-1 on D1 (p less than 0.01) and to 2 micrograms.l-1 on D2 and D3 (NS). Comparison of these two groups showed a difference only on D2 with regard to somatotrophin (p less than 0.05) and on D2 and D3 with regard to prolactin (p less than 0.025 and p less than 0.05). These results are discussed. They do not indicate any fundamental difference in the endocrine response to aggression in relation to the two types of anaesthetic studies.

Anesthesia↗
PubMed1980

[Effect of androgens on the growth of skin fibroblasts in culture].

The effect of DHT on skin fibroblasts proliferation was investigated by measurements of DNA concentrations and of 3H-thymidine incorporation variations. 1 nM DHT did not stimulate fibroblasts growth in either genital nor non genital skin fibroblasts. At higher concentrations, DHT inhibited cell proliferation. It can be concluded that in cell culture, fibroblasts growth is not dependent from androgen receptor content.

Adult↗
PubMed1980

[Urinary estrone and estradiol levels in the diagnostic presumption of pregnancy (author's transl)].

Urinary estrone and estradiol levels have been measured using an enzymatic method during the late lutheal phase in 17 female volunteers trying for a pregnancy and in 10 patients having a treatment for stimulation of ovulation. The profile of urinary estrogenic excretion appears to be different if a pregnancy started or not during the studied cycle. These patterns allow a good diagnostic presumption before the following missing menses, which can be useful when dealing with women treated for infertility and when plasmatic dosage of hCG or beta hCG cannot be rapidly available.

Chorionic Gonadotropin↗
PubMed1980

[Prolactin secretion during sleep at puberty. Preliminary results (author's transl)].

Plasma prolactin was measured in six normal boys, during night sleep, with simultaneous recording of EEG for determination of the various stages of sleep. Peaks of prolactin appear clearly during cycles of rapid sleep: in prepuberty, the average of night peaks of prolactin is higher than that in post-puberty subjects. These results suggest indirectly, a participation of prolactin in prepuberty adrenal maturation.

Adolescent↗