The aim of prenatal genetic diagnosis is to give parents the option of terminating affected pregnancies. For most X linked conditions specific diagnosis is not possible and the only option is induced abortion of all male fetuses, of which half would be unaffected. An altemative is offered by preimplantation diagnosis of sex in embryos obtained by in vitro fertilisation and selective transfer of...

It is generally believed that progesterone is essential for inducing the changes in oviduct and uterus necessary for embryo viability and implantation in a number of mammalian species. The aim of this study was, in the rhesus monkey, to examine in conception cycles with and without early luteal phase antiprogestin (mifepristone; RU 486) treatment: (i) the growth status of preimplantation embryo...

Alkaline phosphatase (AP) activity has been assayed in frozen sections of preimplantation mouse embryos by an azo-dye cytochemical method. The results indicate that during preimplantation mouse development AP activity is first expressed between the 8- and 16-cell stages and develops in all cells by the late morula stage. During blastocyst formation AP activity is lost or greatly reduced in trop...

Indomethacin, an inhibitor of prostaglandin synthesis, depressed the incorporation of [3H]uridine into RNA of mouse preimplantation embryo, when it was injected in vivo or added in vitro. In contrast, prostaglandin F2 alpha decreased the inhibitory effect of indomethacin, when it was added in vitro with indomethacin. The results of these experiments suggest that prostaglandin F2 alpha plays a r...

Cystic fibrosis (CF) is the most common genetic disease among Caucasians. Duchenne muscular dystrophy (DMD) is one of the most common X-linked genetic disorders. The CF and DMD genes were discovered a few years ago, which provided the possibility for prenatal diagnosis and preimplantation diagnosis of CF and DMD by using specific DNA analysis. In this article, CF, DMD, the process of the identi...

Embryo biopsy for preimplantation genetic diagnosis can be performed on the oocyte/zygote, cleavage stage embryo, or blastocyst, but the majority of centres perform cleavage stage biopsy. Single-cell diagnosis is undertaken by the polymerase chain reaction or fluorescent in-situ hybridization. Technical difficulties have arisen with preimplantation genetic diagnosis, such as allele dropout and ...

Undifferentiated mouse embryonal carcinoma (EC) cells are capable of transactivating the adenovirus EIIa promoter in the absence of its normal transactivator, E1A protein, suggesting that EC cells contain an E1A-like activity. In an effort to identify where this activity appears during normal mouse development, mouse oocytes and preimplantation embryos were injected with plasmids containing the...

OBJECTIVE To characterize speech perception performance in elderly cochlear implant users compared with younger adult users. DESIGN Case-control retrospective analysis from January 1, 1999, to January 28, 2008. SETTING Tertiary care, academic practice cochlear implant program. PATIENTS Medical records for 78 patients with age at implantation of 65 years or older were analyzed for ear-spec...

The current morphologically based selection of human embryos for transfer cannot detect chromosome aneuploidies. So far, only biopsy techniques have been able to screen for chromosomal aneuploidies in the in vitro fertilization (IVF) embryos. Preimplantation genetic diagnosis (PGD) or screening (PGS) involves the biopsy of oocyte polar bodies or embryonic cells and has become a routine clinical...

Preimplantation embryo development involves four stages: fertilization, cell cleavage, morula and blastocyst formation. During these stages, maternal and zygotic epigenetic factors play crucial roles. The gene expression profile is changed dramatically, chromatin is modified and core histone elements undergo significant changes. Each preimplantation embryo stage has its own characteristic epige...