Wednesday, April 23, 2008

Embryos from the skin sample:

Embryos from the skin sample:

Technical pioneer-will extract stem cells from human clone and create customized tissues for transplantation

(Matters published in the edition of the Correio Braziliense 18/1/08)

Rodrigo Craveiro

For the first time in the history of medicine, researchers announced Tuesday used the five cloning to create human embryos from adult cells of the skin. The feat was disclosed yesterday by Stemagen Corp.. -- Private company dedicated to the production of personalized stem-cell, based in La Jolla (CA) - and caused uproar in the scientific means. In the Post interview, Andrew French, the company's chief scientist and leader of the study, was incisive in saying that the embryos are potential sources of embryonic stem-cells. "The cells' manufactured 'are unique and grow at all times, can differentiate into 200 types of tissue," said the pioneer. Published in the journal Stem Cells, the search results have been received cautiously by geneticists. Distrust is attributed to counterfeit of 11 lines of stem-cells by South Korean Hwang Woo-suk, in 2005.

French explained that to produce embryos in their early stage of development. "To do this, we had access to 29 eggs from three donors. We've removed the DNA of eggs and replaced with cells in the skin of two adult men. The embryo began to split up a call blastócito phase, which has only between 15 and 100 cells, "explained the scientist. This small cell population would be capable of providing stem-cells. "In all, five blastócitos generate," celebrated.

To be sure that the resulting embryos were clones pure, French sent them to an independent laboratory, which was taken a "DNA fingerprint". The examination showed that in three of the five blastócitos there was no remnant of maternal DNA. "The mitochondrial DNA of the egg donor was present in one of blastócitos, confirming the cloning," recalled French.

The digital examination of the DNA used a series of genetic markers that the cells of the skin compared to the cloned embryo. "We wanted to be sure that we had a fragmentation cell in the hands," explained the author of the study. In that case, it was necessary to destroy the embryo so that all cells are discussed further. French out ethical clashes with the breakthrough: "We do not want to start a pregnancy. All we want is to produce stem-cells.


The scientist's Corp. Stemagen. sees very useful and practical applications in medicine over the long term. "We hope to use the mechanism to generate stem-cell transplant in adaptable to individuals, which descartaria any possibility of rejection," he said. According to French, the resulting stem cells-cells may lead to custom of the liver, heart and neurons. "They are a kind of box of tools to replace other tissues," predicted.

A pioneer in research with stem cells, Robert Lanza, of Advanced Cell Technology (in Massachusetts), showed skepticism. "We need to be ultracuidadosos, after the scandal of Hwang, not to cometermos the same mistake", warned in the interview to news agency Reuters. "I would believe in the feat, but not yet convinced me," added the scientist, who tries to create human embryonic stem-cells.

The Cypriot Panayiotis Zavos, director of the Institute of andrology in the United States, assured the Post that his team was responsible for the actual creation of the first cloned human embryos. "We have not had that destroying them to harvest stem cells, but the transfer to women who could not get pregnant," she said. "If the Stemagen did what claims, repeated or reproduced our work, published in several scientific journals," Zavos attacked.

Medicine into the future

Carlos Gropen *

Another step toward the future imagined by the visionary French writer Jules Verne, which anticipated the way of man to Lua. Skin cells taken from adult donors, have the potential to create human embryonic stem cells-which may mean a new range of treatments in a tangible future. The studies represent the hope of cure for many diseases such as Alzheimer's evil, spinal cord injuries, strokes, among others.

It would be a source of stem cells-can be used in rebuilding of damaged tissue with the restoration of the functions of the body. The roughly, would be as bricks to rebuild a damaged wall. For that to happen it is necessary that the body recognises the stem-cell and activate the mechanism of differentiation - the transformation of it into a fabric identical to the region injured.

What is the usefulness of an ear in the middle of the brain? Or, yarn hair grow inside the heart? Indeed, the details of how the three-dimensional differentiation and its organization - the formation of bodies - are beyond the current knowledge. Despite possible and potentially applicable to situations units, you should remember that most treatment is still experimental. Until that is done all the safety tests, prudence is the best medicine.

* Medical, consultant Correio Braziliense of health and Professor of the Faculty of Medicine, UNB

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