Científicos estadounidenses abren el camino a la clonación humana
Un grupo de científicos estadounidenses ha conseguido por primera vez células madre embrionarias con el mismo ADN de un adulto, con lo que se ha dado un paso más hacia una posible clonación humana.
Según los resultados de un ensayo publicados en la revista 'Cell', el trabajo es el primer éxito en humanos de la técnica que dio origen a la oveja Dolly, pero los autores insisten en que no se trata de obtener personas clonadas, sino en llegar a la fase de blastocito del embrión (alrededor de los cinco o seis días de desarrollo) para extraer las células madre.
"Estas podrían luego diferenciarse en tejidos que el paciente necesitara para un autotrasplante, que como tendrían el mismo material genético que el receptor, podrían usarse sin riesgo de rechazo", explicó el jefe del estudio Shoukhrat Mitalipov, de la Universidad de Salud y Ciencias de Oregon.
Además, describe que la técnica utilizada es la de transferencia nuclear. "Se toma un óvulo de una donante, se le extrae el núcleo y se le inserta de una célula adulta del posible receptor. Luego, la célula se activa, y empieza a dividirse en los primeros pasos del desarrollo embrionario. Al llegar a la fase de blastocito, se destruye y se obtienen las células madre. Esto sucede porque al cambiar el material el óvulo deja de tener una sola cadena de ADN para tener dos, que es la situación que se da en la naturaleza cuando hay una fecundación", dijo.
Este método ya se había ensayado con éxito en animales pero nunca había funcionado en personas, y los autores del artículo son conscientes de que se ha dado, al menos en teoría, un paso hacia la clonación humana, por lo que subrayan que esta investigación "está directamente dirigida a conseguir células madre para usarlas en el futuro para combatir enfermedades".
Sin embargo, "los avances en la técnica de transferencia nuclear conducen a menudo a la discusión pública sobre los aspectos éticos de la clonación humana, ese no es nuestro objetivo. Y tampoco creemos que nuestro hallazgos puedan ser utilizados por otros para avanzar en esa dirección", resume Mitalipov.
Japanese Scientists Prove The Possibility of Teleportation
The future is already here: for the first time in the world, a team of Japanese scientists managed to implement teleportation! A beam of light was moved from point A to point B.
For the purpose of the experiment, Noriyuki Lee and his colleagues divided light into elementary particles - photons. They kept only one photon that carried the information about the rest beam. This photon wasentangled at the quantum level with another photon, which was located at point B. It turned out that these two photons instantaneously affected each other, being physically located in different places. Thanks to this phenomenon, the original beam was at the same moment recreated elsewhereusing the information carried by the photon.
It is interesting that the possibility of quantum entanglement of elementary particles was suggested by Albert Einstein in 1935, but in that time even the physicist himself considered his theory absurd. However, subsequently physicists have proved that quantum entanglement exists, and already in our days some companies have created technology of secure communication channels on the basis of this phenomenon.
Cause of aging reversed in mice: Human trials may start next year
By Grant Banks December 22, 2013
reversed aging in mice
With the wide-ranging benefits of reducing disease and enabling a longer, healthier life, reversing the causes of aging is a major focus of much medical research. A joint project between the University of New South Wales (UNSW) in Australia and Harvard Medical School that restored communication within animal cells has the potential to do just that, and maybe more. With the researchers hoping to begin human clinical trials in 2014, some major medical breakthroughs could be just around the corner.
The researchers have managed to reverse the effects of aging in mice using an approach that restores communication between a cell’s mitochondria and nucleus. Mitochondria are the power supply within the cell, generating the chemical energy required for key biological functions. When communication breaks down between mitochondria and the cell's control center, the nucleus, the effects of aging accelerate.
A team led by David Sinclair, a professor from UNSW Medicine who is based at Harvard Medical School, found that by restoring this molecular communication, aging could not only be slowed, but could be reversed. The technique has implications for treating cancer, type 2 diabetes, muscle wasting, inflammatory and mitochondrial diseases.
The study follows on from previous research showing that exercise and certain dietary habits, such as calorie restriction or the intake of resveratrol (found in red wine and nuts), slowed the breakdown of intra-cellular communication and therefore aging.
Responsible for this breakdown is a decline of the chemical NAD. By increasing amounts of a compound used by the cell to produce NAD, Professor Sinclair found that he could quickly repair mitochondrial function.
“It was shocking how quickly it happened,” co-author Dr Nigel Turner, an ARC Future Fellow from UNSW’s Department of Pharmacology says. “If the compound is administered early enough in the aging process, in just a week, the muscles of the older mice were indistinguishable from the younger animals."
Looking for indicators of insulin resistance, inflammation and muscle wasting, the researchers found that the tissue of two-year-old mice given the NAD-producing compound for just one week resembled that of six-month-old mice. They said that this is comparable to a 60-year-old human converting to a 20-year-old in these specific areas.
They also found that young mice given the same compound became "supercharged" in certain aspects, suggesting that the technique could have benefits for young, healthy humans as well.
Another significant finding, with possible implications for cancer treatment, was the involvement of the chemical HIF-1. This chemical is responsible for the disruption of communication within the cell and is naturally produced by the body when deprived of oxygen. Cancer is also thought to be responsible for activating HIF-1 and the researchers have now found it also switches on during aging.
“It’s certainly significant to find that a molecule that switches on in many cancers also switches on during aging,” said Ana Gomes, a postdoctoral scientist in the Sinclair lab. “We're starting to see now that the physiology of cancer is in certain ways similar to the physiology of aging. Perhaps this can explain why the greatest risk of cancer is age.”
The researchers are now looking at the longer-term outcomes of the NAD-producing compound in mice and how it affects the mouse as a whole, including whether it will give the mice a longer, healthier life. The researchers hope to start clinical trials on humans late in 2014.
“There’s clearly much more work to be done here, but if those results stand, then aging may be a reversible condition, if it is caught early,” says Professor Sinclair.
The team's study is published in the journal Cell.