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Biomedical subjects

Y Lefebvre

Publications and source records attributed to Y Lefebvre.

At least 37 records · Page 2Linked to original sources
PubMed1976

Maternal, fetal, and intra-amniotic hormonal and biologic changes resulting from a single dose of hydrocortisone injected in the intra-amniotic compartment.

A single intra-amniotic injection of 500 mg. of hydrocortisone sodium succinate was done 48 hours before elective cesarean section in nine patients in week 39 of gestation. Following that single injection, estriol values fell in all three compartments. Cortisol was rapidly increased in the maternal compartment but returned to normal levels at the time of cesarean section in maternal and umbilical vein cord plasma while remaining elevated in the amniotic compartment. Progesterone was increased in the fetal and amniotic compartments but remained essentially unchanged in the maternal compartment. The foam test was constantly improved in the direction of an intermediary or positive test and the quantitative lecithin-sphingomyelin values were increased by almost twofold. In our series, none of our babies developed a respiratory distress syndrome nor had any difficulty with the first breath or the Apgar score. We did not deliver any low-birth-weight infants and the creatinine values were even improved by our injection.

Adolescent↗
PubMed1975

Synthesis and biological properties of 17 alpha-furylestradiol and dihydroequilin derivatives.

A series of 17alpha-furylestradiol and dihydroequilin derivatives was synthesized by reacting the appropriate 3-substituted estrone and equilin with 2- or 3-furyllithium. The oral estrogenic activity of the compounds was compared with that of mestranol. In the Allen-Doisy test, the 17alpha-(3-furyl) analogs were 4-19 times as potent orally as the standard in rats but they were less active in mice. Acetylation of the 17-alcohol or replacement of the 3-furyl by a 2-furyl group produced a decrease in activity. In the mouse uterotrophic assay in mice the compounds were less effective than mestranol and exhibited very shallow dose-response curves.

17-Ketosteroids↗
PubMed1975

Synthesis and estrogenic properties of 7 alpha,8 alpha-epoxy- and 7 alpha, 8 alpha-methyleneestradiols.

A series of 7alpha,8alpha-expoxyestradiol derivatives with ethynyl, 2- or 3-furyl, or 2-thienyl substituents in the 17alpha position was prepared. The products were highly active orally in the Allen-Doisy test in rats, but most of them were only weakly active in the uterotrophic assay in the mouse. A 7alpha,8alpha-methylene analog and a 7alpha,8alpha-difluormethylene analog were less active than the corresponding epoxides.

Animals↗
PubMed1975

Oxidation of furans. 3. Estrogenic properties of lactones and anhydrides derived from the oxidation of 17alpha-[3-furyl]estradiol derivatives.

The oxidation of 17alpha-[3-furyl]estradiol derivatives and the estrogenic properties of the resulting isomeric 17,21-and 17,23-dihydroxy-19,24-dinor-17alpha-chola-1,3,5(10)20(22)-tetraenoic acid(20leads to 23) gamma-lactones as well as those of the related 17-hydroxy-19-nor-17alpha-pregna-1,3,5(10)-triene-20,21-dicarboxylic acid anhydrides and gamma-lactones are described. Of these, only lactones 3c,e,h and 5b retained the same degree and profile of estrogenic activity as the starting 17alpha-[3-furyl]estradiols.

Anhydrides↗
PubMed1970

Anatomical and functional changes induced by oral contraception.

The hormonal contraceptives seem to have no direct effect on cervical carcinoma or dysplasia, but they are responsible for the appearance of glandular adenomatous hyperplasia of the endocervix.The long-term use of progestins is responsible for the inactive appearance of the ovaries, with thickening of the tunica albuginea, rare follicle growth, occasional fibrosis of the stroma and a decreased DNA formation.After stopping oral and injectable hormonal contraceptives the first cycle is usually long and cases of amenorrhea have been reported. The causes of secondary amenorrhea probably lie in the hypothalamus and/or the ovaries.The time lapse between cessation of oral contraception and conception is between 5.8 and 6.5 months. No increase in abortion has been noted, but abortuses and ova have an increased polyploid tendency and incidence of chromosome breaks. Further investigations of larger series are necessary to provide definite proof. Meanwhile it would seem advisable that after cessation of hormonal contraception there should be a time lapse of six to eight months before a patient becomes pregnant.

Abnormalities, Drug-Induced↗