Controversies in micro-injection.
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Acrosome↗
Biomedical subjects
R Edirisinghe
Publications and source records attributed to R Edirisinghe.
Improved pregnancy rate after transfer of embryos grown in human fallopian tubal cell coculture.
OBJECTIVE: To evaluate the embryonic behavior in vitro and the pregnancy and implantation rates of embryos grown in a human ampullary cell coculture system. DESIGN: In a prospective study, two pronuclei embryos were cultured on human ampullary feeder layers up to the two to six-cell and blastocyst stages and replaced either as tubal, uterine, or sequential transfers. SETTING: Assisted reproductive technology program in a university-based hospital. PATIENTS: Fifty women with a mean age of 35.6 years who went through a single coculture cycle. Thirty of the patients were admitted for in vitro fertilization (IVF) and 20 for tubal embryo transfer (TET). RESULTS: The overall clinical pregnancy rate (PR) for all 50 patients was 44% per cycle (IVF, 37%; TET, 55%) and the implantation rate was 31.8% (IVF, 31.0%; TET, 32.6%). Sixty-eight percent of pregnant patients were over 35 years, and 68% had two previously failed assisted reproduction cycles. Five of 9 patients who received sequential transfers became pregnant. Three of the 22 pregnancies aborted (2 after sequential transfer), and there was one ectopic. Overall, 88% of two to six-cell stage embryos were of good quality. CONCLUSIONS: The human ampullary coculture system produces better quality embryos, increased numbers of blastocysts with improved PRs and implantation rates. The beneficial effects of the feeder layer may be through the release of embryotrophic factors and detoxification of the medium by the cells. Coculture is a new concept in assisted reproduction and has tremendous potential in boosting conception rates by mimicking the in vivo environment.
Adult↗
The evaluation of various culture media in combination with dimethylsulfoxide for ultrarapid freezing of murine embryos.
Bicarbonate-buffered HTF medium, Medicult, and T6 are as effective as PB1 medium when used in combination with DMSO in ultrarapid freezing of two-cell mouse embryos. However, the use of phosphate-buffered T6 results in reduced in vitro development and inner cell mass size as compared with bicarbonate- and Hepes-buffered T6 when used with 3.5 M of DMSO. Hence, the use of this media for ultrarapid freezing should be avoided when this concentration of DMSO is used.
Animals↗
Micro-insemination sperm transfer (MIST) and its application to male subfertility: current strategies to improve results.
It can be difficult to achieve a pregnancy for patients with severe male factor subfertility. Hence, micro-manipulation techniques, have been applied to this problem. Direct deposition of sperm into the oocyte under the zona (micro-insemination sperm transfer, MIST) has improved the fertilisation rates, but pregnancy rates have been very low. This paper describes the possible new strategies to improve the technique currently. They include methods to improve sperm recovery, to improve acrosome reaction, to improve the quality of embryos by using co-cultures and to wait for good cleavage before transfer, and to improve luteal phase support. There are also many new techniques being developed which may contribute to further pregnancy successes. They include the use of electro-fusion, laser-fusion and the Xenopus cell-free system.
Female↗
In-vitro fertilisation today.
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Fertilization in Vitro↗
Determination of fetal sex in cattle by cytologic examiantion of amniotic fluid.
Amniotic fluid smears (n = 134) of bovine fetuses (69 males, 65 females) at various stages of gestation were stained by the Papanicolaou method. Percentage counts of eosinophilic, orangeophilic, and cyanophilic cells were determined by examining 500 cells per sample. The cyanophilic cell count was significantly (P less than 0.001) higher for the females (37% +/- 3% to 47% +/- 3%) than for the males (19% +/- 2% to 32% +/- 3%). Significant differences, however, were not recorded with the eosinophilic and the orangeophilic cell counts. The percentage cyanophilic count could therefore be used as a method of prenatal sex determination.
Amniotic Fluid↗