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Biotech / Medical : Stem Cell Research -- Ignore unavailable to you. Want to Upgrade?

To: SnowShredder who wrote (103)	4/29/2005 3:56:27 PM
From: LJM	Read Replies (1) \| Respond to of 495

timesonline.co.uk Britain April 29, 2005 Pioneering stem-cell surgery restores sight By Sam Lister, Health Correspondent A PIONEERING form of surgery has been developed that can restore the sight of patients by using stem cells to encourage damaged eyes to repair themselves. A team of British specialists has successfully treated more than a dozen patients with impaired corneas by transplanting human stem cells grown in a laboratory on to their eyes. Recent operations on ten patients showed that the technique restored sight in seven cases of people who had been blinded after getting acid, alkali and boiling metal in their eyes, or because of congenital disorders. Many of the patients treated at the Centre for Sight, Queen Victoria Hospital, in East Grinstead, West Sussex, had been told that they had no hope of getting their sight back, or had already undergone failed corneal transplants. The process involves taking stem cells, which occur naturally in the eye, and developing them into sheets of cells in the laboratory. These are transplanted on to the surface of the eye where they are held in place by an amniotic membrane, which dissolves away as the sheet fuses to the eye. Sheraz Daya, an ophthalmic surgeon leading the Sussex team, which has spent five years perfecting the technique, said that doctors had been astonished at how the cells appeared to trigger the eye’s natural regeneration of its damaged surface. Tests on the patients after a year revealed no trace of the DNA of the stem-cell donor, meaning that the repair was carried out by the eye’s own cells — a permanent healing process that does not require long-term use of powerful drugs to suppress the patient’s immune system. Mr Daya said: “The technique not only works, but there was no donor tissue there. That is what really blew our minds. The cells appeared to have been shed from the eye and replaced by the patient’s own, much more hardy, cells.” The team, including scientists at the hospital’s McIndoe Surgical Centre, now hopes to identify the processes at work, which might then be used to trigger the repair of other damaged tissue around the body. Details of the trial were revealed this month at an international conference of eye specialists in America. All the patients in the trial had corneas that had become damaged because they no longer had limbal stem cells, which are normally under the eyelid and help to keep the surface of the cornea clear, protecting it. Edward Bailey, who lost his sight after caustic acid landed in his left eye while he was cleaning pipes at a yoghurt factory, said that the operation had transformed his life. “It was the most emotional moment,” Mr Bailey, 65, said. “I couldn’t believe it. For ten years all I had seen was shades of black and grey, then after I had the operation the nurse came by and I saw a flash of blue from her uniform. I went home and when I took the patch off my eye, I had my vision back. It is only when you lose something like sight that you realise how precious it is.” Nadey Hakim, a consultant surgeon at St Mary’s Hospital, London, said that it was likely that such action could be mimicked in other organs, thus reducing the need for organ transplants. Professor Hakim said: “The hope is that stem cells will one day be used to generate large quantities of cells and tissues and possibly entire organs damaged by disease and injury. It is a dream.”

To: SnowShredder who wrote (103)	6/23/2005 1:26:44 AM
From: SnowShredder	Read Replies (2) \| Respond to of 495

Scientists derive stem cells from human skin fwiw Best of Luck, SS english.people.com.cn >>>> Scientists derive stem cells from human skin A group of US scientists reported on Wednesday that they have isolated stem cells from human skin, cultivated them in the laboratory, and differentiated them into fat, muscle and bone cells. The study, published in the journal Stem Cells and Development, is the first to show the ability of a single adult stem cell to become multiple tissue types, according to Anthony Atala, director of the Wake Forest Institute for Regenerative Medicine who led the research. "Because these cells are taken from a patient's own skin, there would not be problems with organ or tissue rejection. These cells can provide a valuable resource for tissue repair and for organs as well," said Atala. The researchers grew mesenchymal stem cells (MSC), a type of stem cell normally found in bone marrow. They were able to isolate single stem cells using tissue samples from 15 donors. Then, they grew the stem cell in culture dishes in the laboratory. The scientists used hormones and growth factors to coax the stem cells into becoming fat, muscle and bone cells. When the differentiated cells were seeded onto three- dimensional molds and implanted in mice, they maintained features consistent with bone, muscle and fat tissue. "Progeny of cell lines established from a single dermal MSC could be differentiated into adipogenic, osteogenic and myogenic lineages, consistent with the conclusion that we established a clonal, multipotential, somatic MSC cell line," wrote the researchers. The promise of stem cells lies in their ability to develop into specialized types of cells and to replicate themselves. Scientists hope to harness the potential of stem cells and use them to replace damaged cells and tissue in conditions such as spinal cord injuries, diabetes, Alzheimer's disease, stroke and burns. Most scientists believe that stem cells from human embryos are the most versatile type of stem cell because they have the potential to form any cell or tissue in the body. But they are also exploring the potential of stem cells from adults. In addition to skin, the cells have been identified in bone marrow, the brain and blood from the umbilical cord. Compared to bone marrow, a skin biopsy is easy to take, so it offers advantages for clinical use. The cells can be obtained from any small sample of human skin, the researchers noted. Next, the research team hopes to test the function of the tissue that was created from the stem cells in long term. "Clonal growth of MSCs presents profound implications in our understanding of differentiation and development, and should provide a valuable resource for tissue repair," their paper said. The cells have potential to be used both in cell therapy and tissue engineering, namely the science of growing tissues and organs in the laboratory. For cell therapy, laboratory-grown cells would be injected into the body to replace breast tissue removed by surgery, to fill in the gaps in bone fractures or replace muscle damaged by injury. "The ability to engineer tissues from a patient's own cells may overcome two major problems in transplantation medicine: immune rejection and tissue shortage," Atala said. Source: Xinhua