WASHINGTON, Nov. 16 (JTA) – Patients in need of tissue and organ transplants are one step closer to receiving laboratory-produced replacements, as a result of a breakthrough made by a team of American and Israeli scientists. In January, the scientists became the first to extract human embryonic stem cells – the parent cells of all tissues in the body – and the first to trigger continual cell division. If programmed correctly, this cell division will develop into human tissues and allow scientists to create, from a petri dish, anything from human heart muscle to bone marrow and skin. The advance is expected to benefit transplant medicine, drug discovery and basic developmental biology. Doctors may utilize it in the future to treat victims of heart disease, diabetes, Parkinson’s and Alzheimer’s diseases, spinal cord injuries and some kinds of cancers. “Although a great deal of research needs to be done before these cells can lead to human therapies, I believe that in the long run they will revolutionize many aspects of transplant medicine,” said James Thomson, a developmental biologist at the University of Wisconsin at Madison and the head of an international research team that published news of the scientific breakthrough in the Nov. 6 issue of the journal Science. Joseph Itskovitz, an Israeli in-vitro fertilization specialist and a member of the medical faculty at the Technion-Israel Institute of Technology in Haifa, joined Thompson’s collaboration efforts two years ago and provided the study with embryos and research assistance. “We are searching now for a way to control the differentiation of the cells,” Itskovitz said in a telephone interview. “We cannot direct the cells changing into other human tissue cells – it happens on its own randomly.” With so many scientific hurdles to cross, Thomson does not expect his labs to create specialized cells and tissues overnight. “We’re looking at 10 to 15 years before these treatments go to trial on humans,” Terry Devitt, a spokesman for Thomson said. “Science is a slow process.” Due to the lack of suitable organ donors, the breakthrough is especially critical to transplant surgeons who hope to use the technology to repair or replace damaged or diseased tissues or organs, according to Jon Odorico, a transplant surgeon at the University of Wisconsin at Madison. “The principal theoretical advantages of this type of treatment for organ replacement over current organ transplantation is the fact that cells can be grown in large quantity, and can be genetically engineered outside the body to escape immune attack,” Odorico said. Thomson expects the most immediate use of the human embryonic stem cell technology will be for the development of new drugs. Drugs currently in the trial stage will be injected into the cells to check for their impact on the cells, including possible side effects. The announcement puts the American and Israeli researchers at the head of a pack of scientists who have worked for 17 years to capture and to isolate human embryonic stem cells. Devitt explained the embryos used in this project were originally intended for in-vitro fertilization clinics. “Often times, when a couple uses in-vitro fertilization there are leftover cells,” Devitt said. “Some couples chose, in writing, to donate the embryos to research.” Eventually scientists hope to manipulate a human adult cell and clone it to become an embryonic cell. Once a string of dividing embryonic stem cells can be controlled, its uses are unlimited, Iskovitz said.