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S Wintenberger-Torres

Publications and source records attributed to S Wintenberger-Torres.

4 recordsLinked to original sources
PubMed1982

Cytochemical studies of uterine and trophoblastic surface coats during blastocyst attachment in the ewe.

A glycoprotein coat was demonstrated on the outer surface of both the uterine and trophoblastic cells using ruthenium red, cationized ferritin, concanavalin A-peroxidase and phosphotungstic acid in HCl. No changes were observed on the uterine epithelial surface of cyclic or pregnant animals before or during blastocyst attachment (Day 15). However, the cytochemical reactions were different on the trophoblastic cells of blastocysts at Days 13 and 15, the ruthenium red and cationized ferritin sites of reaction and the concanavalin A receptors being more homogeneously distributed on the outer surface of Day-15 trophoblast. The phosphotungstic acid staining demonstrated a glycoprotein substance between the trophoblast and the uterine epithelium in adhesion areas by Day 18. The results suggest that biochemical changes occur in the composition or distribution of the trophoblastic cell coat during the process of blastocyst attachment in the ewe.

Animals↗
PubMed1980

Transfer of cow blastocysts after sexing.

We obtained 174 Charolais cow blastocysts at day 13 (D(13)) after superovulation and slaughter of 24 donor heifers. Using de Wecker's scissors, we sampled 1 10 to 1 3 of the total blastocyst volume. After colcemid treatment, hypotonic shock, fixation and Giemsa staining, the sex of 149 blastocysts (60 %) was determined. The main difficulty in sexing was the absence of metaphase or the presence of incomplete metaphases on the preparations. During manipulation, the portion of the blastocyst to be transferred was stored at 37 degrees C in a medium of 20 % fetal calf serum containing 80 % B(2) under an atmosphere of 90 % nitrogen, 5 % O(2) and 5 % CO(2) for 6 to 7 hours. After sex determination, the blastocysts were put into an artificial insemination straw and placed with a catheter at the base of the uterine horns. Twenty-eight blastocysts were transferred into both horns of 14 recipient Charolais heifers; 4 heifers (28 %) had an extended cycle and 3 (21 %) were pregnant. When 2, 3 or 4 blastocysts were transferred into the ipsilateral horn with the corpus luteum, 20 to 25 % of the recipients had an extended cycle and 37, 40 and 75 %, respectively, were pregnant. The number of surviving embryos per recipient never exceeded 2.

Journal Article↗
PubMedDate not supplied

Conceptus attachment in the ewe: an ultrastructural study.

Scanning and transmission electron microscopic observations were made on trophoblast, caruncles and intercaruncular areas during the attachment of the conceptus. Three stages were determined: 1. From day 14 on, precontact was established and the conceptus appeared to be immobilized in the uterine lumen. On the centres of the caruncles which were depressed and folded the epithelial cells developed bulbous cytoplasmic protrusions. Throughout the free life of the conceptus, the trophoblast cells showed an abundant covering of microvilli. 2. On day 15, apposition occurred: most microvilli on the surface of the trophoblast disappeared. 3. Between days 16 and 18, adhesion began as a result of the interpenetration of the uterine microvilli and cytoplasmic projections of the trophoblast cells. During that stage trophoblast giant cells appeared and the uterine epithelium was turned into syncytial masses; however, it was apparently not destroyed later on. Between the caruncles, the trophoblast developed finger-like villi which invaded the lumen of the uterine glands from days 15 to 18. During their short life-time (they vanish at day 20), these trophoblastic differentiations may anchor the pre-attachment conceptus and absorb the histotrophic secretions of the glands.

Animals↗