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Author(s): Wei Zhou 1,2,3,4,5,6,7, Wanbing Feng 1,2,3,4,5,6,7, Jinli Chang 1,2,3,4,5,6,7, Jingmei Hu 1,2,3,4,5,6,7, Fuxia Li 1,2,3,4,5,6,7, Kuona Hu 1,2,3,4,5,6,7, Jiejing Jiao 1,2,3,4,5,6,7, Xinyi Xue 1,2,3,4,5,6,7, Ting Lan 1,2,3,4,5,6,7, Wenjing Wan [...], Background Frozen embryo transfer (FET) has become a widely employed assisted reproductive technology technique. There have historically been concerns regarding the long-term metabolic safety of FET technology in offspring due to pregnancy-induced hypertension and large for gestational age, both of which are well-recognized factors for metabolic dysfunction of children. Therefore, we aimed to compare the metabolic profiles of children born after frozen versus fresh embryo transfer at 2 to 5 years of age. Methods and findings This was a prospective cohort study. Using data from the "Assisted Reproductive Technology borned KIDs (ARTKID)," a birth cohort of offspring born from assisted reproductive technology at the Institute of Women, Children and Reproductive Health, Shandong University, China. We included 4,246 singletons born after FET (n = 2,181) and fresh embryo transfer (n = 2,065) enrolled between 2008 and 2019 and assessed the glucose and lipid variables until the age of 2 to 5 years. During a mean follow-up of 3.6 years, no significant differences were observed in fasting blood glucose, fasting insulin, Homeostatic Model Assessment of Insulin Resistance Index, total cholesterol, triglycerides, low-density lipoprotein-cholesterol, and high-density lipoprotein-cholesterol levels between offspring conceived by fresh and frozen embryo transfer in the crude model and adjusted model (adjusted for parental age, parental body mass index, parental education level, paternal smoking, parity, offspring age and sex). These results remained consistent across subgroup analyses considering offspring age, the stage of embryo transfer, and the mode of fertilization. Results from sensitivity analysis on children matched for age within the cohort remains the same. The main limitation of our study is the young age of the offspring. Conclusions In this study, the impact of FET on glucose and lipid profiles during early childhood was comparable to fresh embryo transfer. Long-term studies are needed to evaluate the metabolic health of offspring born after FET.

c. Monitoring Compliance Through Data Collection Once mandatory reporting requirements for embryo transfer are in place, how would the designated enforcer assure compliance with the statutory scheme? What strategies could [...]

Author(s): Amander T. Clark Author Affiliations: Human embryo implantation modelled in microfluidic channels Each year, millions of women around the world experience early pregnancy loss[sup.1] . Most pregnancy losses occur [...], An innovative microfluidic device has enabled the modelling of the events that occur in human embryos when they implant in the wall of the uterus. It could be used to help understand early pregnancy loss. Innovative microfluidic device enables study of embryo development.

During human embryo implantation, trophectoderm mediates adhesion of the blastocyst to the uterine epithelium. The rapid growth of the embryo and invasion of the maternal tissue suggest adhesion-induced activation of the embryonal cells. We show here that ligation of trophinin, a homophilic cell adhesion molecule expressed on trophoblastic cells, induces tyrosine phosphorylation in trophinin-expressing trophoblastic HT-H cells. The phosphorylation could be induced in HT-H cells with the binding of trophinin-expressing cells or anti trophinin antibodies. Trophinin-dependent tyrosine phosphorylation was associated with actin reorganization. We also isolated trophinin-binding peptides from phage libraries. These peptides exhibited the consensus sequence GWRQ and seemed to reproduce the effects of trophinin-mediated cell adhesion. Upon binding of a GWRQ peptide, HT-H cells became highly proliferative and motile. HT-H cells expressed ErbB family receptors and bound EGF and heparin-binding EGF-like growth factor (HB-EGF), but ErbB family receptor phosphorylation in these cells required GWRQ. In the absence of GWRQ, trophinin interacted with the cytoplasmic protein bystin, which binds to ErbB4 and blocks its autophosphorylation. In HT-H cells, GWRQ peptide dissociated trophinin from bystin, and ErbB4 was activated. Culturing monkey blastocysts in the presence of the peptide increased total number and motility of the trophectoderm cells. These results suggest that trophinin-mediated cell adhesion functions as a molecular switch for trophectoderm activation in human embryo implantation. BYSL | ErbB4 | pregnancy | receptor tyrosine kinase | stem cells

I. INTRODUCTION Preimplantation genetic diagnosis (PGD) is an assisted reproductive technology (ART) that offers great potential for preventing genetic disease, but also raises troubling ethical concerns. Because of these concerns, [...]

A randomized controlled trial is designed to determine whether there are differences in the rates of pregnancy and delivery between women randomly assigned to undergo transfer of a single cleavage-stage embryo and those assigned to undergo transfer of a single blastocyst-stage embryo. The results show that the transfer of a single blastocyst-stage embryo significantly increases the likelihood of pregnancy and delivery as compared with transfer of a single cleavage-stage embryo.

The therapeutic use of nuclear transfer does not require the formation of a fetus but relies on the direct differentiation of functional cells in nature. A cloned human embryo would have little potential to develop into a healthy human being, as it would lack attributes that are essential to the beginning of normal human life.

Statutes employ definitions to give content to the law. Bill C-13, the Assisted Human Reproduction Act, (1) is no exception. Definitions, by definition, give meaning to terms, explain their scope, [...]

Human embryonic stem (ES) cells are pluripotent cells that may be used in transplantation medicine. These cells can be induced to differentiate into cells from the three embryonic germ layers both in vivo and in vitro. To determine whether human ES cells might be rejected after transplantation, we examined cell surface expression of the MHC proteins in these cells. Our results show very low expression levels of MHC class I (MHC-I) proteins on the surface of human ES cells that moderately increase on in vitro or in vivo differentiation. A dramatic induction of MHC-I proteins was observed when the cells were treated with IFN-[gamma] but not with IFN-[alpha] or -[beta]. However, all three IFNs induced expression of MHC-I proteins in differentiated human ES cells. MHC-II proteins and HLA-G were not expressed on the surface of undifferentiated or differentiated cells. Ligands for natural killer cell receptors were either absent or expressed in very low levels in human ES cells and in their differentiated derivatives. In accordance, natural killer cytotoxic assays demonstrated only limited lysis of both undifferentiated and differentiated cells. To initiate a histocompatibility databank of human ES cells, we have isotyped several of the published ES cell lines for their human leukocyte antigens. In conclusion, our results demonstrate that human ES cells can express high levels of MHC-I proteins and thus may be rejected on transplantation.

On the top floor of the Gold Museum in Bogota, Colombia, visitors are ushered into a dark, windowless room; heavy doors are closed behind them. They stand in the darkness [...]