Researchers succeed in growing mouse embryos ex utero solely from stem cells.

Synthetic mouse embryos grew ex utero to 8.5 days and showed early stages of organogenesis.

La regla de los 14 días a debate: un análisis crítico desde la bioética / La regla dels 14 dies a debat: una anàlisi crítica des de la bioètica / The 14-day rule under debate: A critical analysis from Bioethics

The aim of this article is to critically analyze the arguments used in defense of the 14-day rule, which refers to research and experimentation with human embryos. This rule was first proposed more than forty years ago, and many countries have adopted it and included it in their respective legislation. However, after four decades, science today demands an international debate in which the limit imposed by the rule is urgently reviewed, which makes it impossible for scientists to be able to investigate with embryos created in the laboratory beyond the 14 days limit. To this end, we will examine two fundamental texts in which the rule originated, analyzing from bioethics whether the arguments contained in them are coherent and whether they can currently be sustained. In addition, we will consider to the reasons offered by science for its extension, bearing in mind that any change in the rule must alwayscorrespond to the values present in society at the time.(AU)

El objetivo que perseguimos con el presente artículo es analizar críticamente los argumentos utilizados en defensa de la regla de los 14 días, referida ésta a la investigación y experimentación con embriones humanos. Dicha regla fue propuesta por primera vez hace ya más de cuarenta años, siendo muchos los países que se acogieron a ella incluyéndola en sus respectivas legislaciones. No obstante, después de cuatro décadas, la ciencia exige hoy un debate internacional en el que sea revisado con urgencia el límite que la norma impone, la cual imposibilita a los científicos poder investigar con embriones creados en el laboratorio más allá de la frontera de los 14 días. Para ello, repararemos en dos textos fundamentales en los que la regla tuvo su origen, analizando desde la bioética si los argumentos contenidos en ellos son coherentes y si pueden actualmente sostenerse. Además, atenderemos a las razones ofrecidas desde la ciencia para llevar a cabo su ampliación, teniendo en cuenta que cualquier cambio en la norma deberá tener siempre su correspondencia con los valores presentes en la sociedad del momento.(AU)

L'objectiu que perseguim amb el present article és analitzar críticament els arguments utilitzats en defensa de la regla dels 14 dies, referida aquesta a la recerca i experimentació amb embrions humans. Aquesta regla va ser proposada per primera vegada fa ja més de quaranta anys, sent molts els països que es van acollir a ella incloent-la en les seves respectives legislacions. No obstant això, després de quatre dècades, la ciència exigeix avui un debat internacional en el qual sigui revisat amb urgència el límit que la norma imposa, la qual impossibilita als científics poder investigar amb embrions creats en el laboratori més enllà de la frontera dels 14 dies. Per a això, repararem en dos textos fonamentals en els quals la regla va tenir el seu origen, analitzant des de la bioètica si els arguments continguts en ells són coherents i si poden actualment sostenir-se. A més, atendrem les raons ofertes des de la ciència per a dur a terme la seva ampliació, tenint en compte que qualsevol canvi en la norma haurà de tenir sempre la seva correspondència amb els valors presents en la societat del moment.(AU)

Challenges and Considerations during In Vitro Production of Porcine Embryos.

Genetically modified pigs have become valuable tools for generating advances in animal agriculture and human medicine. Importantly, in vitro production and manipulation of embryos is an essential step in the process of creating porcine models. As the in vitro environment is still suboptimal, it is imperative to examine the porcine embryo culture system from several angles to identify methods for improvement. Understanding metabolic characteristics of porcine embryos and considering comparisons with other mammalian species is useful for optimizing culture media formulations. Furthermore, stressors arising from the environment and maternal or paternal factors must be taken into consideration to produce healthy embryos in vitro. In this review, we progress stepwise through in vitro oocyte maturation, fertilization, and embryo culture in pigs to assess the status of current culture systems and address points where improvements can be made.

Reverse transcription priming methods affect normalisation choices for gene expression levels in oocytes and early embryos.

Mammalian oocytes and embryos rely exclusively on maternal mRNAs to accomplish early developmental processes. Since oocytes and early embryos are transcriptionally silent after meiotic resumption, most of the synthesised maternal mRNA does not undergo immediate translation but is instead stored in the oocyte. Quantitative RT-PCR is commonly used to quantify mRNA levels, and correct quantification relies on reverse transcription and the choice of reference genes. Different methods for reverse transcription may affect gene expression determination in oocytes. In this study, we examined the suitability of either random or oligo(dT) primers for reverse transcription to be used for quantitative RT-PCR. We further looked for changes in poly(A) length of the maternal mRNAs during oocyte maturation. Our data indicate that depending on the method of reverse transcription, the optimal combination of reference genes for normalisation differed. Surprisingly, we observed a shortening of the poly(A) tail lengths of maternal mRNA as oocytes progressed from germinal vesicle to metaphase II. Overall, our findings suggest dynamic maternal regulation of mRNA structure and gene expression during oocyte maturation and early embryo development.

Induction of short-term pseudopregnancy in gilts by the administration of estradiol benzoate or estradiol dipropionate to achieve ovulatory synchronization for embryo collection.

A study was conducted to investigate whether ovulation in gilts could be synchronized for embryo collection by the administration of estradiol benzoate (EB) or estradiol dipropionate (EDP) to induce pseudopregnancy, followed by the treatment with prostaglandin F2α (PGF2α ) on 10 days after. Ten gilts each received a total of 20 mg of EB or EDP on Day 10 or EB on Day 10 and 14 to induce pseudopregnancy (Day 0 = onset of estrus). Donors received PGF2α 10 or 15 days (as a control) after the first administration of estrogens and subsequently eCG and hCG, and were then inseminated artificially. The embryos were collected 7 days after the administration of hCG, and assessed for embryo yield and their developmental stages. All protocols resulted in good embryo yield (9.8-13.2 embryos in average), and the embryos showed average ability to develop to the expanded blastocyst stage (3.29-4.03 as developmental scores) without any significant differences among the protocols. These results suggest that the administration of PGF2α 10 days after the treatment of gilts with EB or EDP would allow synchronization of ovulation and embryo collection, as well as shortening the period from estrus detection to embryo collection, thus improving embryo collection efficiency.

¿Modificar o no modificar el genoma de nuestra descendencia? Algunos comentarios a raiz de la Declaración del Comité de Bioética de España sobre la edición genómica en humanos / To modify or not to modify the genome of our offspring? Some comments following the Declaration of the Spanish Bioethics Committee on genomic editing in humans / Modificar o no modificar el genoma de la nostra descendència?. Alguns comentaris arran de la Declaració del Comitè de Bioètica d'Espanya sobre l'edició genòmica en humans

La modificación genética de la línea germinal humana presenta grandes problemas de carácter ético y jurídico. El Comité de Bioética de España ha publicado una Declaración ofreciendo una respuesta a estos retos. Este artículo analiza críticamente su postura, subrayando la escasa consistencia de cualquier argumento que pretenda censurar cualquier forma de mejora en la salud humana. Con tal fin, se exponen cuestiones como la relación entre dignidad humana y modificación genética o la inconsistencia de la apelación al argumento de la pendiente resbaladiza en este contexto. Asimismo, se afirma la necesidad de trazar distinciones entre las intervenciones que afectan a bienes absolutos, como la salud, y los que no lo son

Genetic modification of the human germline presents major ethical and legal problems. The Spanish Bioethics Committee has published a Declaration offering a response to these challenges. This article critically analyzes its position, underlining the scarce consistency of any argument that attempts to censor any form of improvement in human health. To this end, questions such as the relationship between human dignity and genetic modification or the inconsistency of the appeal to the argument of the slippery slope in this context are raised. At the same time, this paper highlights the need to draw distinctions between interventions that affect absolute goods, such as health, and those that are not

La modificació genètica de la línia germinal humana presenta enormes problemes de caràcter ètic i jurídic. El Comitè de Bioètica d'Espanya ha publicat una Declaració oferint una resposta a aquests reptes. Aquest article analitza críticament la seva postura, subratllant l'escassa consistència de qualsevol argument que pretengui censurar qualsevol forma de millora en la salut humana. Amb tal fi, s'exposen qüestions com la relació entre dignitat humana i modificació genètica o la inconsistència de l'apel·lació a l'argument del pendent relliscós en aquest context. Així mateix, s'afirma la necessitat de traçar distincions entre les intervencions que afecten béns absoluts, com la salut, i els que no ho són

Embryo collection from pigs post-pseudopregnancy induced by estradiol dipropionate.

We aimed to define whether embryo collection carried out after pseudopregnancy was of similar outcome and quality as after artificial abortion. To induce pseudopregnancy, 30 gilts or sows were given 20 mg intramuscular estradiol dipropionate (EDP) 10-11 days after the onset of estrus. Ten additional pigs were inseminated artificially at natural estrus as a control group. Prostaglandin F2α (PGF2α ) was administered twice with a 24 hr interval beginning 15, 20, or 25 days after EDP-treatment (n = 10 per group) or between 23 and 39 days after artificial insemination in control pigs. Following this, all pigs were given 1,000 IU equine chorionic gonadotropin and 500 IU human chorionic gonadotropin (hCG) and then inseminated. Embryos were recovered 6 or 7 days after hCG treatment and outcome was recorded. There was no significant difference in the number of normal embryos collected from the pigs with PGF2α initiated at different time points or from the control group. Embryonic developmental stages 7 days after hCG treatment also did not differ among groups. These results indicate that the use of EDP to induce pseudopregnancy, followed by PGF2α administration to synchronize estrus for subsequent embryo harvest, is a suitable alternative to the artificial abortion method.

Generation of Blastocyst-like Structures from Mouse Embryonic and Adult Cell Cultures.

A single mouse blastomere from an embryo until the 8-cell stage can generate an entire blastocyst. Whether laboratory-cultured cells retain a similar generative capacity remains unknown. Starting from a single stem cell type, extended pluripotent stem (EPS) cells, we established a 3D differentiation system that enabled the generation of blastocyst-like structures (EPS-blastoids) through lineage segregation and self-organization. EPS-blastoids resembled blastocysts in morphology and cell-lineage allocation and recapitulated key morphogenetic events during preimplantation and early postimplantation development in vitro. Upon transfer, some EPS-blastoids underwent implantation, induced decidualization, and generated live, albeit disorganized, tissues in utero. Single-cell and bulk RNA-sequencing analysis revealed that EPS-blastoids contained all three blastocyst cell lineages and shared transcriptional similarity with natural blastocysts. We also provide proof of concept that EPS-blastoids can be generated from adult cells via cellular reprogramming. EPS-blastoids provide a unique platform for studying early embryogenesis and pave the way to creating viable synthetic embryos by using cultured cells.

Of mice and human embryos: is there an ethically preferred order of preclinical research on new assisted reproductive technologies?

It is widely acknowledged that the responsible introduction of new assisted reproductive technologies (ARTs) requires preclinical safety research, including the use of animal models and human embryos. However, the moral sensitivity of human embryo research has led to regulations and guidance stating that human embryos may only be used for research that cannot also be conducted with animals. We call this the 'use animals first' (UAF) rule. In the field of ART research, this translates into the notion of an ideal chain of consecutive preclinical research steps, where research using human embryos may only be considered as a further step after promising results have been obtained in animals first. This may lead to research ethics committees requiring animal studies that are in fact a waste of time and money, while exposing animals to an infringement of their wellbeing for no good purpose. In this paper, we explore the possible moral arguments behind the UAF-rule and test their validity. We conclude that there are no convincing grounds for upholding this rule and recommend replacing it.

Human embryos from induced pluripotent stem cell-derived gametes: ethical and quality considerations.

Protocols for successful differentiation of male and female gametes from induced pluripotent stem cells have been published. Although culture of precursor cells in a natural microenvironment remains necessary to achieve terminal differentiation, the creation of human preimplantation embryos from induced pluripotent stem cell-derived gametes is technically feasible. Such embryos could provide a solution to the scarcity of human cleavage-stage embryos donated for research. Here, we discuss current technology, major research-related ethical concerns and propose the norms that would assure the quality and reliability of such embryos.

Use of the Coelomic Grafting Technique for Prolonged ex utero Cultivation of Late Preprimitive Streak-Stage Rabbit Embryos.

Due to its morphological similarity with the early human embryo, the pregastrulation-stage rabbit may represent an appropriate mammalian model for studying processes involved in early human development. The usability of mammalian embryos for experimental studies depends on the availability of whole embryo culture methods facilitating prolonged ex utero development. While currently used culture methods yield high success rates for embryos from primitive streak stages onward, the success rate of extended cultivation of preprimitive streak-stage mammalian embryos is low for all previously established methods and for all studied species. This limits the usability of preprimitive streak-stage rabbit embryos in experimental embryology. We have tested whether the extraembryonic coelom of 4-day-old chick embryos may be used for prolonged ex utero culture of preprimitive streak-stage rabbit embryos (stage 2, 6.2 days post coitum). We found that, within this environment, stage 2 rabbit blastocysts can be cultured at decreasing success rates (55% after 1 day, 35% after 2 days, 15% after 3 days) up to a maximum of 72 h. Grafted blastocysts can continue development from the onset of gastrulation to early organogenesis and thereby form all structures characterizing age-matched controls (e.g. neural tube, somites, beating heart). Compared to normal controls, successfully cultured embryos developed at a slower rate and finally showed some structural and gross morphological anomalies. The method presented here was originally developed for whole embryo culture of mouse embryos by Gluecksohn-Schoenheimer in 1941. It is a simple and inexpensive method that may represent a useful extension to presently available ex utero culture systems for rabbit embryos.

Production of hand-made cloned buffalo (Bubalus bubalis) embryos from non-viable somatic cells.

Use of non-viable somatic cells for hand-made cloning (HMC) can enable production of cloned animals from tissues obtained from elite or endangered dead animals. Buffalo skin fibroblast cells were rendered non-viable by heat treatment and used for HMC. Although fusion (93.6 ± 1.72 vs 67.1 ± 2.83%) and cleavage (90.3 ± 1.79 vs 65.8 ± 1.56%) rate was lower (P < 0.001) than that for controls, blastocysts could be successfully produced. However, blastocyst rate (34.1 ± 2.43 vs 6.9 ± 2.18%, P < 0.001) and total cell number of blastocysts (TCN, 221.3 ± 25.14 vs 151.1 ± 21.69, P < 0.05) were lower and apoptotic index (4.8 ± 1.06 vs 10.9 ± 1.21) was higher (P < 0.001) than that of controls. In another experiment, ear tissue of slaughterhouse buffaloes was preserved in mustard oil at room temperature for 48 h following which somatic cells were harvested by enzymatic digestion and used for HMC. Although fusion (96.8 ± 1.48 vs 84.2 ± 3.19%), cleavage (89.6 ± 3.59 vs 77.2 ± 3.99%), and blastocyst rate (36.9 ± 7.45 vs 13.1 ± 6.87%) were lower (P < 0.01), TCN (223.0 ± 27.89 vs 213.3 ± 28.21) and apoptotic index (3.97 ± 0.67 vs 5.22 ± 0.51) of blastocysts were similar to those of controls. In conclusion, HMC can be successfully used for production of blastocysts from non-viable cells and from cells obtained from freshly slaughtered buffaloes. This can pave the way for the restoration of farm or wild animals by HMC if somatic cells could be obtained within a few hours after their death.

Recommended Ethical Safeguards on Fertilization of Human Germ Cells Derived from Pluripotent Stem Cells Solely for Research Purposes.

Production of human fertilized embryos by using germ cells derived from pluripotent stem cells (PSCs) entails ethical issues that differ fundamentally depending on the aim. If the aim is solely to conduct research, then embryo generation, utilization and destruction must respect for the human embryo as having the innate potential to develop into a human being. If the aim is human reproduction, this technology must never be used to manipulate human life, confuse social order, or negatively affect future generations. Researchers should distinguish the aims and then accordingly establish a consensus on the safeguards needed to proceed with scientifically significant and socially accepted research, or otherwise set a moratorium. Currently, in Japan, germ cell production from human PSCs is permitted, whereas fertilization of these germ cells is not. The Japanese Expert Panel on Bioethics in the Cabinet Office has proposed that all of the following conditions must be met to approve fertilization for research purposes: (1) the research is significant for the life sciences and medicine; (2) the benefits or anticipated benefits are socially accepted; (3) human safety is assured; and (4) safeguards are put in place. If fertilization is ethically approved, I recommend the following safeguards: limitation of the purpose to improving conventional ART as an initial step; permitted culture of human embryos until the appearance of the primitive streak; restriction of the number of embryos produced to the minimum necessary; prohibition of transplantation into a human or animal uterus; and provision of human-derived ova that are not required for ART treatment.

Análisis bioético de la generación de «bebés medicamento» / Bioethical analysis of the generation of saviour sibling

Se denominan 'bebés medicamento' a, los niños concebidos con el propósito de que sean donantes compatibles para salvar, por medio de la determinación del antígeno leucocitario humano (HLA) de embriones, a un hermano que sufre una enfermedad congénita inmunitaria. Toda esta situación actual genera varios interrogantes éticos sobre el 'uso' o 'utilidad' de estas nuevas técnicas, el presente estudio pretende analizar las cuestiones bioéticas generadas más relevantes (AU)

The so‐called saviour sibling are those babys that were conceive with the purpose to become in compatible donor to save a sibling with immune congenital diseases through the identification of the human leukocyte antigen (HLA). In this entire new frame has born an ethical debate about the use of these techniques. This study tries to analyze the main bioethical question that this new situation provokes (AU)

Feasibility of Computed Tomography in a Multicenter COPD Trial: A Study of the Effect of AZD9668 on Structural Airway Changes.

INTRODUCTION: The aim of this study was to establish the feasibility of using computed tomography (CT) in a multicenter setting to assess structural airway changes. METHODS: This was a 12-week, randomized, double-blind, placebo-controlled, Phase IIb trial using CT to investigate the effect of a novel, oral, reversible neutrophil elastase inhibitor, AZD9668 60 mg twice daily (BID), on structural airway changes in patients aged 50-80 years with chronic obstructive pulmonary disease (COPD) (ex-smokers). PRIMARY OUTCOME VARIABLE: airway wall thickness at an extrapolated interior perimeter of 10 mm (AWT-Pi10). Secondary outcome variables: fifth-generation wall area %; air trapping index; pre- and post-bronchodilator forced expiratory volume in 1 s (FEV1); morning and evening peak expiratory flow and FEV1; body plethysmography; EXAcerbations of Chronic pulmonary disease Tool (EXACT); Breathlessness, Cough, and Sputum Scale (BCSS); St George's Respiratory Questionnaire for COPD; and proportion of reliever-medication-free trial days. Safety variables were also assessed. RESULTS: There was no difference between placebo (n = 19) and AZD9668 (n = 17) for AWT-Pi10 at treatment end. This was consistent with results for most secondary variables. However, patients randomized to AZD9668 experienced an improvement versus placebo for morning and evening FEV1, and EXACT and BCSS cough and sputum scores. AZD9668 60 mg BID was well tolerated and no new safety concerns were identified. CONCLUSIONS: This study confirmed the feasibility of using CT to assess structural airway changes in COPD. However, there was no evidence of improvements in CT structural measures following 12 weeks' treatment with AZD9668 60 mg BID. FUNDING: AstraZeneca.