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D Lescoat

Publications and source records attributed to D Lescoat.

25 records · Page 2Linked to original sources
PubMed1983

Influence of intra-uterine infusions of blastocyst tissue homogenate on the ultrastructure of spayed rabbit uterus.

Scanning electron microscopic observations were made on uterine horns of ovariectomized rabbits after intra-uterine infusions of preimplantation blastocyst tissue homogenate and on control uterine horns. After two successive infusions of 5 or 6 day embryo homogenate, the secretory activity of luminal and glandular cells was considerably stimulated. These findings showed that preimplantation blastocyst alone, in the absence of ovaries, could directly act upon endometrium. The nature of the active factor was discussed.

Animals↗
PubMed1982

Influence of adrenalectomy on maturation of gonadotrophin function in the male rat.

The effects were studied of adrenalectomy performed at 25 days of age on the maturation of LH function and the testes during puberty (i.e. 30-50 days of age) in the male rat. In intact rats the plasma LH level increased and then decreased and the plasma testosterone level increased progressively. In adrenalectomized rats the plasma levels of LH and testosterone did not vary significantly over the same period of time. Adrenalectomy decreased the plasma levels of LH and testosterone. The different perturbations in hormonal balance induced a decrease in the size of the seminiferous tubules and a delay in spermatogenesis.

Adrenalectomy↗
PubMed1982

[Blastocyst-endometrial relationships before ovo-implantation in the rabbit (author's transl)].

Transmission and scanning electron microscope appearances of epithelium in a pregnant uterine horn at and between the eggs, in a non-gravid horn of a unilaterally pregnant animal, and in the uterine horn of a pseudopregnant animal provided evidence of short-, medium- and long-range blastocyst effects. While cessation of mitotic division at 5 to 6 days post-coitum is solely the result of ovarian activity, the changes that occur in the shape of uterine epithelial cells apex seem to be due to the combined actions of ovaries and eggs. The development of apical club-shaped structures between 4 and 6 days, more pronounced in the pregnant horn compared with the pseudopregnant horn is apparently determined by ovarian and ovular effects. On the other hand, blastocysts induce the apparition of crater-cells at days 4 and 5 only in the pregnant horn : this could involve a mechanical or a chemical action of short- and medium-range egg effects. Similarly, on days 5 and 6, apical elongations are seen in the uterine regions occupied by the eggs, this finding points to a possible short-range blastocyst action.

Animals↗
PubMedDate not supplied

Anomalous distribution of nuclear basic proteins in round-headed human spermatozoa.

An electrophoretic analysis of nuclear proteins has been carried out in normal and in round-headed human spermatozoa. Results revealed an anomalous distribution of nuclear basic proteins in round-headed spermatozoa. They contained more histones and especially more intermediate proteins and less protamines than normal spermatozoa.

Electrophoresis, Polyacrylamide Gel↗
PubMedDate not supplied

Ultrastructural and immunocytochemical study of P1 protamine localization in human testis.

Two monoclonal antibodies (MAbs) directed against human protamine P1 were realized. Anti-P1 specificity was assessed by western-blot and confirmed by ELISA. Monoclonal antibody 97-3 was selected. Protamine P1 was specifically demonstrated in human testis by immunoelectron microscopy, using 97-3 MAb and an indirect post-embedding immunogold technique. Our results clearly demonstrated the precise time of appearance of P1 protamine in the nuclei of human spermatids. P1 first appeared in the nucleus of step 5 spermatids and its concentration was increased in steps 6-8 spermatids, cytoplasm was not labelled.

Antibodies, Monoclonal↗
PubMedDate not supplied

Decondensation of human sperm nuclei and HP1 protamine degradation from normospermia and asthenospermia in Xenopus egg extracts.

The process of human sperm decondensation has been studied in vitro in cytoplasmic extracts prepared from unfertilized Xenopus laevis eggs. The chromatin decondensation-recondensation cycle was divided into four stages according to chromatin appearance. Spermatozoa from normospermia and asthenospermia were evaluated according to their capacity to reach these stages, and their DNA integrity was assessed by acridine orange (AO) staining. We observed a significant difference between normospermia and asthenozoospermia in the ability to achieve the cycle of chromatin decondensation-recondensation. These results correlated with AO staining. The role of human protamine 1 degradation in the decondensation process was evaluated by immunostaining. It was found not to be a prerequisite for the earlier stage of chromatin decondensation and it was not implied in the latest stages of pronuclear development.

Acridine Orange↗