Descrubrimientos sobre reprogramación nuclear merecen el premio Nobel en 2012 / Discoveries on nuclear reprogramming deserves the Nobel prize in 2012

Este artículo fue escrito para honrar a J.B Gurdon y S. Yamanaka, laureados con el Premio Nobel en Fisiología p Medicina 2012 "por el descubrimiento de que las células maduras pueden ser reprogramadas para volverse pluripotentes". Se presentan en forma concisa sus aportes científicos y reseñas biográficas. J.B. Gardon, en Inglaterra, demostró hace 50 años en anfibios que al trasplantar el núcleo de una célula intestinal a un huevo u ovocito enuncleado se obtiene una célula totipotente que se convierte en un embrión y se desarrolla hasta convertirse en una rana adulta, lo cual implica la conservación de genoma en el proceso de diferenciación y la resersibilidad de dicho proceso. Estos descubrimientos llevaron a que otros autores realizaran la clonación de mamiferos utilizando el núcleo de células somáticas y la obtención de células madre pluripotentes a partir de los embrines que se producen in vitro por el desarrollo de las células totipotentes. Se mencionan varias aplicaciones y las contribuciones de Gurdon para comprender el proceso de reprogramación. S. Yamanaka, en Japón, hace seis años, reprogramó al estado embrionario fibroblastos cutáneos de ratones y humanos adultos insertando mediante vectores retrovirales una combinación de los genes de cuatro factores de transcripción: Oct3/4, Sox2, Klf4 y c-Myc. Las células reprogramadas fueron denominadas células madre pluripotentes inducidas. Utilizando la técnica desarrollada por Yamanaka y otras surgidas a raiz de sus descrubrimientos, miles de personas obtienen ahora células madre pluripotentes inducidas a partir de muchas especies y tejidos, incluyendo seres humanos sanos y enfermos. Las células madre pluripotentes o sus derivadas tienen un amplio potencial de aplicación, entre ellas, estudios de embriología y fisiopatología, modelos de enfermedades, descubrimiento de drogas y terapias celulares

This paper was written to honor J.B Gurdon y S. Yamanaka, 2012 Nobel Prize laureates in Physiology or Medicine for "the discovery that mature cells can be reprogrammed to become pluripotent". Their main scientific contributions and biography are presented in a concise manner. JB Gurdon, in England, showed fifty years ago in amphibians that the transplantation of the nucleus of an intestinal cell to an enucleated egg or oocyte produces a totipotent cell that develops into an embryo and adult frog. This implies that cellular differentiation is reversible and the genome is conserved in that process. The discoveries led to the cloning of mammals by other authors using the nucleus of somatic cells and to obtain pluripotent stem cells in vitro from the embryos produced by development of the totipotent cells. Some applications are considered. Gurdon's contribution to the understanding of the reprogramming process is mentioned. S. Yamanaka six years ago in Japan reprogrammed skin fibroblastis from adult mice and humans to the embryonic state by introducing via retroviral vectors a combination of the genes of 4 transcription factors, Oct3/4. Sox2, Klf4 and c-Myc. The reprogammed cells were named induced pluripontent stem cells. Throusands of people are now producing induced pluripotent stem cells from many tissues and species, including healthy and ill humans, using Yamanaka's methods and other techniques stimulated by his work. Pluripotent stem cells or their derivatives have great potential for a wide range of applications including research in embryology and pathophysiology, disease modeling, drug discovery and cell transplantation therapies

Células-tronco: um breve estudo / Stem cells: a brief study

A célula-tronco é uma célula que pode de diferenciar e construir diferentes tecidos no organismo, bem como se auto-replicar. Devido características ,elas funcionam como células coringa, podendo substituir tecidos e/ou doentes. O referido trabalho se propõe a informar ao profissional da saúde o que vem a ser uma célula-troncodas suas origens, função, implicações,aspectos éticos bem como caracterizar a sua evidência no contexto mundial.

The stem cell is a cell that can be defferentiated and constitute different tissues in the organism, as well as if auto-talking back Because of these characteristics they look like as key cell, being able to substitute damaged tissues and/or sick ones. The aim of this work is to inform the professional of the health what it comes to be a stem cell of its orgins, functionss, implications, etical aspects, as well as characterizing its evidence in the worl-wide context.

Perspectivas sanitarias prometedoras del clonaje humano / Promisin health perspectives for human cloning / Perspectivas sanitarias prometedoras da clonagem humano

Para evaluar las promesas del clonaje humano -tanto las terapéuticas como las reproductivas- se puede partir de dos puntos de vista pertinentes: el sanitario y el de la bioética laica. El punto de vista sanitario, a través de políticas públicas de prevención y de promoción de salud adecuadas a las condiciones objetivas existentes, busca proteger la población humana de enfermedades innecesarias. El clonaje puede, en principio, ser parte de una política sanitaria, con la condición de que sean respetados los derechos fundamentales del individuo -en particular el derecho a la autodeterminación personal-, los derechos sociales -como la justicia distributiva- y los derechos de tercera generación -que incluyen medidas protectoras de bioseguridad. La bioética laica busca entender la eticidad del clonaje por medio del análisis racional e imparcial de las implicaciones morales de su uso y, si se considera legítimo, proponerlo como medio para proteger la salud humana. A pesar de sus funciones aparentemente muy diferentes, tanto el clonaje terapéutico como el reproductivo buscan responder al desafío del sufrimiento humano innecesario: el clonaje terapéutico, gracias a la técnica que utiliza célulasmadre o estaminales totipotentes, busca producir órganos y tejidos para eliminar el sufrimiento evitable; el clonaje reproductivo puede también paliar formas de sufrimiento humano innecesario y puede, por ende, ser considerado un caso particular del terapéutico.

To evaluate the promises of human cloning, both therapeutic and reproductive, we can start from two pertinent points of view: health and secular bioethics. Under the point of view of health, though public prevention and health promotion policies, adequate to objective existing conditions, they try to protect human population from unnecessary diseases. Secular bioethics seeks to understand the ethics of cloning through rational analysis, free from the moral implications of its use; and if the conclusion is that it is legitimate, to propose it like a tool to protect human health. In spite of their apparently very different functions, both therapeutic cloning and reproductive cloning seek to respond to the challenge of unnecessary human suffering: therapeutic cloning, thanks to the technique that uses totipotent stem cells, seek to grow organs and tissues to eliminate avoidable suffering; reproductive cloning may also diminish forms of unnecessary human suffering and if can, therefore, to be considered a particular case of therapeutic approach.

Para avaliar corretamente as promessas da clonagem humana, tanto as terapêuticas como as reprodutivas, podese partir de dois pontos de vista pertinentes: o ponto de vista sanitário e o ponto de vista da bioética laica. O ponto de vista sanitário, graças a políticas públicas de prevenção e promoção da saúde adequadas às condições objetivas existentes, visa proteger a população humana do adoecimento não necessário. A bioética laica procura entender a eticidade da clonagem através da análise racional e imparcial das implicações morais de seu uso e, se este for considerado legítimo, propôlo como meio para proteger a saúde humana. Apesar de ter aparentemente funções muito diferentes, tanto a clonagem terapêutica como a reprodutiva buscam responder ao desafio do sofrimento humano não necessário: a clonagem terapêutica, graças à técnica que utiliza célulastronco totipotentes, busca produzir órgãos e tecidos para eliminar o sofrimento evitável; a clonagem reprodutiva pode também eliminar formas de sofrimento humano evitáveis e pode, portanto, ser considerada um caso particular da clonagem terapêutica.

Investigation and Discussion on the Ethical Issues of Therapeutic Cloning and Human Embryo Administrative / 中国医学伦理学

This investigation with questionnaires is about the recognition of ethical issues involved in therapeutic cloning and human embryo managemeat, and its aim is to provide basis for working out ethical guidelines of therapeutic cloning and human embryo management. The investigation has been carried out among professionals in the field of obstetrics, gynecology, and reproductive medicine in the east and west parts of our country including 12 third grade hospitals in Shanghai and Xi'an and 20 maternal and child health stations at the district and county levels with randomized sampling and voluntarily billing the questionnaires without name. A total of 400 feedbacks have been received. The results show that 91. 25% of the investigated persons admit researches on therapeutic cloning, and that majority of them recognize that moral status of embryos develops and changes in accordance with the different stages of embryo development, and put forward some recommendations to strengthen the researches on therapentic cloning and the management of human embryos in order to protect the human dignity and support the researches on therapeutic cloning.