Los pseudoembriones: ¿una inteligibilidad en el límite de nuestra inteligencia? / Pseudo embryos: intelligibility in the limit of our intelligence? / Os pseudo-embriões: uma inteligibilidade no limite de nossa inteligência?

La investigación científica ha posibilitado nuevas esperanzas en la curación de diversas patologías provocadas por procesos degenerativos o por daño directo sobre órganos y tejidos. Una de las líneas de estudio más prometedoras es la utilización de células pluripotenciales, siendo su fuente principal los embriones obtenidos en las técnicas de fertilización asistida. Mas los cuestionamientos éticos respecto a la utilización y destrucción de ellos ha llevado al ingenio humano a desarrollar entidades que semejan embriones pero que no lo serían esencialmente. Si esto fuera cierto, su utilización para obtener esas valiosas células no sería objetable. Estos pseudoembriones desafían a nuestra inteligencia a establecer su verdadero estatuto ontológico. Este trabajo busca reflexionar sobre la dificultad para aplicar los distintos criterios que utiliza nuestra inteligencia para identificar o no, en una serie de entidades naturales y creadas por el hombre, la presencia de un individuo humano con todos sus derechos y dignidad.

Scientific research has made possible new hopes for the cure of diverse pathologies provoked by degenerative processes or by direct damage on organs and tissues. One of the fields of study most promising is the use of pluripotential cells, being their main origin embryos obtained by assisted reproduction techniques. But, the ethical questioning with respect to their use and destruction has guided human talent to develop entities similar to embryos, but not essentially. If this were true, their use to obtain these valuable cells will not be ethically objectionable. These pseudo embryos challenge our intelligence to establish their true ontological statute. This article reflects about the difficulty in applying the different criteria that our intelligence uses to identify or not the presence of a human being with all his/her rights and dignity in a series of natural and created by man entities.

A investigação científica tem possibilitado novas esperanças na cura de diversas patologias provocadas por processos degenerativos ou por dano direto sobre órgãos e tecidos. Uma das linhas de estudo mais promissoras é a utilização de células pluripotenciais, sendo sua fonte principal os embriões obtidos nas técnicas de fertilização assistida. Mas os questionamentos éticos a respeito da utilização e destruição deles tem levado a engenhosidade humana a desenvolver entidades que se assemelham a embriões, mas que não seriam essencialmente. Se isto for certo, sua utilização para obter essas valiosas células não seria objetável. Estes pseudo-embriões desafiam a nossa inteligência a estabelecer seu verdadeiro estatuto ontológico. Este trabalho busca refletir sobre a dificuldade para aplicar os distintos critérios que utiliza a nossa inteligência para identificar ou não, numa série de entidades naturais e criadas pelo homem, a presença de um indivíduo humano com todos os seus direitos e dignidade.

Análisis de patrones morfológicos y anatómicos en la embriogénesis somática del banano Williams (AAA) / Analysis of the morphological and anatomical patterns in the somatic embryogenesis of Williams banana (AAA)

La embriogénesis somática representa una herramienta esencial en el mejoramiento genético y en la micropropagación clonal masiva de bananos mejorados. En el presente trabajo se analizaron los patrones morfológicos y anatómicos que ocurren durante la embriogénesis somática del banano Williams, dirigidos a conocer y mejorar este proceso. En la investigación se establecieron suspensiones celulares embriogénicas (SCE) a partir de callo embriogénico obtenido de manos florales inmaduras masculinas, las cuales originaron abundantes embriones que regeneraron plantas. Hacia los tres meses de cultivo se detectaron embriones somáticos (ES) primarios color blanco-crema en las manos florales de los nudos nueve a doce, contados a partir del ápice floral. Al cuarto mes estos ES primarios dieron origen al callo embriogénico, de color blanco crema, estructura granular, con abundantes ES torpedo en su periferia y con una organización celular en tres diferentes zonas. De este callo se cultivaron porciones pequeñas con ES torpedo en medio de multiplicación durante dos meses, dando origen a la SCE I. La misma se tamizó (250 µm) para establecer la SCE II. El sedimento de células y los agregados celulares embriogénicos de ambas SCE se trasladó a medio de maduración. Transcurridos dos meses los embriones maduros se transfirieron a medio de conversión de embriones, lográndose regenerar plantas completas a partir de las dos semanas. Las SCE produjeron numerosos embriones somáticos maduros y mostraron una buena conversión de embriones a plantas y regeneración de plantas. Este sistema de embriogénesis somática permitió la obtención de plantas funcionales en nueve meses.

Somatic embryogenesis represents an essential tool for the genetic improvement and for the mass clonal micropropagation of the improved banana plant. In this present work morphological and anatomical patterns were analyzed in the somatic embryogenesis of Williams banana, to know and enhance this process. In the investigation embryogenic cell suspensions (ECS) were established from embryogenic callus obtained from floral immature male hands, which gave rise to many somatic embryos that regenerated plants. Towards the three months of culture white-cream primary somatic embryos (SE) were detected in the floral hands of the nodes nine to twelve, counted from the floral apex. At the fourth month this primary SE gave origin to a creamy-white embryogenic callus, with granular structure and abundant SE torpedo on its periphery. Cell organization with three different zones was observed in callus. Small portions of this callus were cultivated in the multiplication medium for two months, to originate ECS I. This ECS was filtered through a mesh (250 µm pore size) to establish the ECS II. The sediment of embryogenic cells and cell clusters of the ECS were moved to maturation media. After two months the mature embryos were transferred to conversion medium, and two weeks later, whole plants were developed. The ECS produced numerous mature SE, which showed good conversion of embryos into plants and plant regeneration. This system of somatic embryogenesis permitted the mass production of functional plants in nine months.

Embriones híbridos como fuente de células troncales embrionarias: [editorial] / Hybrid embryos as a source of embrionic stem cells: [editorial]

The HFEA (Human Fertilisations & Embryology Authority) recently accepted to perform research in hybrid embryos generated by transferring human somatic cell nucleus to cow enucleated oocytes, named cytoplasmatic hybrids. The aim is to obtain a source of embryonic stem cells without the use of human oocytes. The arguments for the approval are to avoid the risk of obtaining human oocytes and that these embryos will not be transferred to a female's womb for its development. Those who oppose the technique argue that it is a manipulation of the beginning of life and a disrespect to the dignity of human life because of the destruction of embryos. Nevertheless, the real nature of this new entity has not been established. Biologically it is an embryo with 99 percent of human genome and animal's cytoplasm, not generated from human gametes, it is not a new genome and it will be used only to cultivate stem cells. It does not seem possible to define its nature beyond any doubts. If it were considered as a human embryo it should be respected and protected as every human being. Once more, scientific progress opens new ethical and legal questions that we cannot answer in a definitive way. Researchers are exploring new roads to obtain pluripotential stem cells which should favor the development of innovative therapies. The main objection is the unavoidable destruction of human embryos, although in this case its origin and nature are not clear.

El diagnóstico de preimplantación genética, el caso Nash y las indicaciones no médicas. De la transgresión del imperativo kantiano a las advertencias de Habermas / Diagnosis of genetic pre-implantations. The Nash case and non-medical indications. From the transgression of Kant's mandate to Habermas' warnings

El diagnóstico de preimplantación genética (DPG) ha extendido sus usos e indicaciones más allá de los limites de la detección de anomalías genéticas. Con el caso Nash se ha dado el primer paso hacia la denominada "construcción de embriones" y por primera vez se ha manipulado un embrión para beneficio de un tercero existente. En este trabajo se analizan los aspectos científicos y bioéticos de este caso. Interpretando las implicaciones de la transgresión del imperativo kantiano, que refiere que todo ser racional debe ser un fin en sí mismo y no un medio al servicio de otros. De igual manera, se exponen las advertencias que ha hecho el filósofo Jurgen Habermas de utilizar el DPG como una técnica de eugenesia positiva. Por último, se muestran otras indicaciones no médicas del DPG y sus dilemas bioéticos.

Effects of L-arginine on development of mouse pre-implantation embryos in culture media with high level of glucose

It is accepted that maternal hyperglycemia causes delay in early embryonic development, spontaneous miscarriage and malformations. According to various studies, some of these problems occur in earlier stages of embryonic developmen especially pre-implantation stage. It seems that elevated glucose level of blood can have important role in this regard as potential teratogen factor. One of cases, which can be related to racousnesses resulting from glucose effects is Nitric Oxide [NO] system disorder in hyperglycemic condition. Some evidences show at first in hyperglycemic condition, L-arginine uptake of media by embryo increases and therefore leads to decrease amount of available L-arginine and since L-arginine is essential substrate for NO production, so it's decrease inhibits NO production. To examine this hypothesis, 2-cell embryos of mice were cultured in media of high concentration of glucose [30mM] and different concentrations of L-arginine [5, 10, 20 mM] and their growth and development were assessed and at the end, embryos were stained by Hoechst 33254 color and the number of their blactocysts were counted by use a Fluorescence microscope. Comparison of embryos culture in HTF culture media with different concentration of glucose and L-arginin showed in high glucose media up to 30 mM affects growth and development of embryos totally and decrease their blactocysts numbers, but addition of 5-10 mM L-arginine to this media significantly improves this condition. On the contrary addition of L-NAME [an antagonist of L-arginine] significantly inhibits the development of pre-implantation embryos. It seems that reduction in NO production in diabetes is due to decreases in amount of available L-arginine, because increase in L-arginine concentration in high glucose media up to 10 mM partially improves high glucose embryo toxicity. Base on acquired result, it seems use of L-arginine or material which cause NO release in media, can have important role in prevention of high glucosis embryo toxicity