Sir, Most of the human embryonic stem cell (hESC) lines have been derived from the inner mass of blastocyst stage embryos, some from 8-cell stage morula (Streclchenko et al., 2004) and some from isolated blastomeres from morulae (Chung et al., 2008). In a very recent abstract, a Belgian team (Van de Velde et al., 2008) elegantly established an embryonic stem cell line from a single blastomere i...

the use of donated embryos has offered hope for infertile couples who have no other means to have children. in iran, fertility centers use fertile couples as embryo donors. in this paper, the advantages and disadvantages of this procedure will be discussed. we conclude that embryo-donation should be performed with frozen embryos thus preventing healthy donors from being harmed by fertility drug...

Abstract Study question What is the developmental potential of monopronuclear (1PN) embryos, and does allowing their use only after confirming biparental inheritance offer a clinical solution for them? Summary answer 1PN embryos demonstrate clear utilisation, euploidy, live birth rates, that warrant routine culture, following testing, in setting. known already Embryos displaying single pronucle...

The importance of mechanical influences during skeletal development has been well established in both experimental studies and computer models. Under conditions of embryonic immobilization, it has been observed that the early stages of joint formation proceed normally (up to and including interzone formation), but the later stages of joint cavitation and maintenance are impaired, resulting in f...

In this article I explore the possibility that contaminants contribute to the increasing prevalence of attention deficit hyperactivity disorder, autism, and associated neurodevelopmental and behavioral problems in developed countries. I discuss the exquisite sensitivity of the embryo and fetus to thyroid disturbance and provide evidence of human in utero exposure to contaminants that can interf...