Post-gastrulation synthetic embryos generated ex utero from mouse naive ESCs

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利用IVF废弃胚胎为核移植受体构建人体细胞克隆胚胎

目的：探讨利用IVF废弃胚胎构建人体细胞克隆胚胎的发育潜能及其在人治疗性克隆应用的可能性。方法：收集2008年7-12月在广州医学院第三附属医院进行体外受精-胚胎移植周期中的多精受精胚胎和MII期体外受精失败卵母细胞,运用显微操作技术构建人体细胞克隆胚胎,观察胚胎发育情况。结果：多精受精胚胎为核移植受体的克隆胚胎能够发育到8-细胞期,受精失败MII期卵母细胞为核移植受体的克隆胚胎能够激活,但不能够卵裂。两种IVF废弃的胚胎构建的人体细胞克隆胚胎在去核成功率,注核成功率上无显著差异（P＆gt;0.05）,但卵裂率和8细胞率上具有显著差异（P＆lt;0.05）。结论：多精受精胚胎比MII期体外受精失败卵母细胞更适合作为人核移植受体细胞。     

Perspectives on human microbiome research ethics

study of ethical, legal, and social implications (ELSI) of human microbiome research has been integral to the Human Microbiome Project (HMP). This study explores core ELSI issues that arose during the first phase of the HMP from the perspective of individuals involved in the research. We conducted semi-structured in-depth interviews with investigators and NIH employees ("investigators") involved in the HMP, and with individuals recruited to participate in the HMP Healthy Cohort Study at Baylor College of Medicine ("recruits"). We report findings related to three major ELSI issues: informed consent, data sharing, and return of results. Our findings demonstrate that investigators and recruits were similarly sensitive to these issues yet generally comfortable with study design in light of current knowledge about the microbiome.     

Improving human embryos selection in IVF: non-invasive metabolomic and chemometric approach

We present here a new metabolomic methodology to predict embryo implantation ability in in vitro fertilization (IVF). In the present study we have included a total of 23 patients scheduled for IVF. Embryos were selected to be transferred by using morphological criteria on day 3 of in vitro culture. The relative amino acid concentrations in the embryo culture media were analyzed by HPLC–MS and HPLC–MS/MS. ¹H NMR metabolomic profiles were also obtained for the embryo culture media. Chemometric models were performed with SIMCA (soft independent modeling of class analogy) for samples from both, non-pregnancy and pregnancy cycles. The metabolic differences between the embryos, with pregnancy and non-pregnancy outcome, can be correlated with the relative amino acid concentrations and with ¹H NMR profiles. We used interval partial least square (iPLS) in order to identify the higher correlation between regions in the ¹H NMR spectra and the embryo implantation capability. The ¹H NMR regions with higher correlation are between 1.2 and 0.5 ppm, that included the signals for cholesterol backbone –C(18)H₃, –CH₃ and CH₂ groups of triglycerides, cholesterol compounds and phospholipids. Our results can allow building a quick, non invasive, useful and feasible chemometric models in order to identify embryos with a high pregnancy rate and embryos unable to achieve successful pregnancies.     

Multiple genotype analysis and sexing of IVF bovine embryos

Twenty-one in vitro-fertilized bovine blastocysts were quartered, lysed and subjected to primer elongation preamplification (PEP) procedure, allowing for the analysis of up to 40 genotypes per quarter embryo. The quarter-embryos were sexed by polymerase chain reaction (PCR) using BRY.1, Bov97M and ZFX/ZFY loci, and then genotyped for k-casein, bovine leukocyte adhesion deficiency (BLAD) and microsatellite D9S1. The mitochondrial cytochrome B locus was used as an internal control with a 95% success rate. The PEP procedure amplified genomic fragments in 93% of all cases. The embryos were identified to be 11 males and 10 females. Sexing accuracy was 87% for BRY.1, 97% for ZFX/ZFY and 100% for Bov97M. False genotyping was due mostly to amplification of BRY.1 in the female embryos and to the nonamplification of the ZFY locus in the male embryos. The results indicate that the combined use of Bov97M and ZFX/ZFY loci is a highly accurate procedure for sexing bovine embryos. Genotyping for kappa-casein, D9S1 and BLAD was successful in 94, 99 and 91% of assays, respectively. Sex ratios and allele frequencies of embryos for gk-casein, BLAD and D9S1 were all close to the observed frequencies in the Israeli Holstein population. These results support the conclusion that the genotyping of embryos is as accurate as that of mature animals. Thus, marker-assisted selection can be efficiently applied at the preimplantation embryo level for loci of economic importance.     

The ethics of human gene transfer

Almost 20 years since the first gene-transfer trial was carried out in humans, the field has made significant advances towards clinical application. Nevertheless, it continues to face numerous unresolved ethical challenges--among them are the question of when to initiate human testing, the acceptability of germline modification and whether the technique should be applied to the enhancement of traits. Although such issues have precedents in other medical contexts, they take on a different character in gene transfer, in part because of the scientific uncertainty and the social context of innovation.     

Donation of embryos for human development and stem cell research

Using donated human embryos for scientific research raises ethical questions about the donation process. We describe a two-stage consent process designed to help couples make informed decisions about embryo disposition. This consent methodology minimizes conflict of interest, respects patient choice, and provides a much-needed resource to patients and the research community.     

Twenty years of human research ethics committees in the Baltic States

Two decades have passed since the first attempts were made to establish systematic ethical review of human research in the Baltic States. Legally and institutionally much has changed. In this paper we provide an historical and structural overview of ethical review of human research and identify some problems related to the role of ethical review in establishing quality research environment in these countries. Problems connected to (a) public availability of information, (b) management of conflicts of interest, (c) REC composition and motivation of REC members, and (d) differing levels of stringency of ethical review for different types of studies, are identified. Recommendations are made to strengthen cooperation among the Baltic RECs.