PubMed · 3194006
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A J McEvoy. 1988-11-17. Embryo definitions.. https://doi.org/10.1038/336198c0
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BACKGROUND: A new law in Italy imposes strict conditions on assisted reproduction at a time when many other countries have become more accepting of these techniques. The law has been criticized both in and outside of the country because of its excessive concern with the status of embryos and disregard for the interests of women and infertile couples. METHODS: Bioethical, legal and policy analysis based on published materials. RESULTS AND CONCLUSIONS: This article shows that ethical concerns about respect for human life and protection of the family and offspring need not burden women and infertile couples to the extent that the new Italian law does. Defining embryos as existing only at syngamy, allowing unpaid sperm and oocyte donation, and permitting the screening of embryos for genetic disease would greatly improve the situation of infertile women in Italy without greatly compromising the values and goals of the Italian law.
BACKGROUND: Androgens play a key role in human fetal development. All androgens act through a single intracellular androgen receptor (AR), which is encoded by a single copy gene on the X chromosome. ARs are expressed as early as 9 weeks in the epithelium and mesenchyme of the urogenital sinus, paramesonephric (Müllerian) and mesonephric (Wolffian) ducts. METHODS: Using immunohistochemistry, we investigated the distribution of ARs in the gonads and lower genital tracts of 54 human fetuses at 8-11 weeks of gestation. Gender was determined by PCR. RESULTS: The AR was expressed in a similar pattern in both male and female fetuses. There appears to be no difference in expression in the mesonephros or the mesonephric ducts when male and female pelvises were compared. Expression in the female paramesonephric duct was within the epithelium, whereas, in the male pelvises, expression was in the mesenchyme of the paramesonephric duct. When AR expression was compared in the ovary and testes, both gonads seem to express AR at 9 weeks, but this expression was extended into the 10th week of gestation in the male. CONCLUSION: The specific pattern of AR expression implies a key role in gonadal development. However, the pattern of staining was similar in the gonads at 8 and 9 weeks in both sexes, although staining persisted longer in the testis until the 10th week. AR expression, therefore, is not a key determinant of human gonadal differentiation.
A study was carried out on the application of magnetic resonance microscopy (MRM) in teaching prenatal human development. Human embryos measuring 8 mm, 15 mm, 18.5 mm, and 22 mm were fixed in a 4% paraformaldehyde solution and sections obtained with magnetic resonance imaging (MRI) were compared to those prepared for light microscopy (LM), using the same embryos. The MRM and LM slices were of a similar quality. In the MRM sections, embryonic organs and systems were clearly visible, particularly the peripheral and central nervous systems, and the cardiovascular and digestive systems. The digitalization and clarity of the MRM images make them an ideal teaching aid that is suitable for students during the first years of a health-science degree, particularly medicine. As well as providing students with their first experience of MRM, these images allow students to access, at any time, all embryos used, to assess changes in the positions of different organs throughout their stages of development, and to acquire spatial vision, an absolute requirement in the study of human anatomy. We recommend that this technique be incorporated into the wealth of standard embryonic teaching methods already in use.