The production of monozygotic twins of preselected parentage by micromanipulation of non-surgically collected cow embryos.
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Journal Article↗
Biomedical subjects
C B Fehilly
Publications and source records attributed to C B Fehilly.
The immune response to hCG-beta subunit in rats and the effects of active immunisation on their fertility.
Immunogenicity of hCG beta subunit (beta-hCG) was investigated in female rats using a variety of immunisation schedules and the effects of active immunisation on fertility were studied. Antibody production to beta-hCG conjugated to tetanus toxoid was pronounced and was not enhanced by the use of adjuvants or presensitisation to tetanus toxoid carrier. Nor was it diminished by using half the amount of beta-hCG-TT conjugate. Boosting resulted in a marked secondary response producing high titre antibody over a prolonged period. Partial or complete infertility occurred in the beta-hCG immunised rats, dependent on which immunisation schedule was employed, implying a threshold titre of antibody required to interfere with pregnancy. No significant effect was observed on the oestrous cycle of the immunised rats or on the gross morphology of their progeny. The results are discussed in relation to the hormonal control of reproductive function in the rat, and the possible application of immunisation against beta-hCG to human fertiliyt.
Animals↗
Interspecific chimaerism between sheep and goat.
In rodents, chimaeric blastocysts produced by combining embryonic cells of two different species have been used in investigations of cell lineage and interaction during development (Mus musculus-Rattus norvegicus, M. musculus-Clethrionomys glareolus, M. musculus-Mus caroli). However, interspecific chimaerism also offers new approaches to the study of reproductive incompatibilities between species and may even allow such incompatibilities to be neutralized, thus improving the chances of successful hybridization and interspecific embryo transplantation. We report here the production of sheep-goat chimaeras by embryo manipulation and the use of interspecific chimaerism to allow successful interspecific embryo transplantation in sheep and goats.
Animals↗
Treatment of male infertility by in vitro fertilization: factors affecting fertilization and pregnancy.
IVF was attempted in more than 100 couples where the man was considered to be the cause of the infertility. 57% of all oocytes were fertilized and embryo replacement was achieved in 60-70% of cases. Pregnancies following IVF were established in cases with a long duration of infertility and different male factors such as oligospermia, teratospermia, asthenospermia and auto-immunity. Almost 50% of men with very low numbers of active spermatozoa (0.5 X 10(6)/ml motile spermatozoa) were able to establish pregnancy. No correlation was found between the percentage motility and the chance of fertilization in cases with abnormal semen, but a reduction of the incidence of fertilization was noticed in cases with extreme oligospermia (5 X 10(6)/ml) where 41% of the oocytes were fertilized. The results of the post coital hamster egg tests were inaccurate in predicting the outcome of IVF. The collection of split ejaculates, and the careful preparation of spermatozoa using sedimentation and layering methods proved to be beneficial, improving sperm motility and raising the chance of fertilization.
Embryo Transfer↗