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îãòðéí îñúéøéí éòãé àøåëé èååç


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#1 davidishalom1

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Posted 05 April 2006 - 07:19 PM


çáøéí é÷øéí:
äîàîø äîåáà ìäìï On a Scaffold in the Lab, Doctors Build a Bladder
îù÷ó úåôòä îàåã îòðééðú áú÷ùåøú åáöéáåøéåú, äéùøàìéú åäòåìîéú. ääúòìîåú äëîòè îåçìèú ùì äú÷ùåøú åäöéáåøéåú îääùìëåú äòöåîåú ùì ùìáéí îú÷ãîéí éåúø ùì äèëðåìåâéä äîúåàøú áîàîø.
äîàîø ìòéì îãååç ùëáø áåöò áôåòì åáäöìçä èéôåì ÷ìéðé ùì äùúìú àéáø îäåðãñ, áî÷øä æä ùìôåçéú äùúï. áòúéã, ééöåø åäçìôú ø÷îåú éáåöò áèëðåìåâéú øôåàä øâ'ðøèéáéú ùì úàé âæò, ùîùîòåúä, äéëåìú ìäðãñ îúàé äâæò ùì äàéðãéåéãåàì òöîå ëì àéáø áâåôå, áîéãä åéäéä öåøê ìäçìéó àú ìéáå, àå òåøå, àå òéðéå, àå îòøëú äòöáéí äîøëæéú ùìå, ëì àéáø åø÷îä àçøú áâåôå, äèëðåìåâéä úàôùø æàú åâí ìáèç úéåùí. àåìí áòöí äèëðåìåâéä äæå òöîä, îãäéîä äøáä éåúø, îùåí ùäéà úàôùø ééöåø àéáøéí îäâðåí ùì äàãí òöîå, ùééäåðãñå ìäéåú öòéøéí åàôéìå ìäéùàø öòéøéí åùìà úçåì ìâáéäí äúåôòä ù÷ééîú ìâáé ëì àåøâðéæí áèáò, úåôòú ääæã÷ðåú, îçìú ääæã÷ðåú. éúàôùø ìîáåâøéí åâí ìæ÷ðéí îåôìâéí, ìäçìéó áäãøâä àú ø÷îåú åàéáøé âåôí ìø÷îåú åàéáøéí öòéøéí éåúø åáùìá éåúø îú÷ãí ùì èëðåìåâéä æàú, ùàéáøéí îäåðãñéí àìå ìà úçåì òìéäí îçìú ääæã÷ðåú. âí úäìéëé ääùúìä áàîöòåú èëðåìåâéåú ððå-îãéñéï, øôåàú ððåèëðåìåâéä, éäéå ìà ôåìùðéåú åìà é÷øåú áîùê äæîï. äîùîòåú ùì ëì æä, äéà äéëåìú ìäùéâ ëáø áòúéã äðøàä ìòééï áòåã ëòùøéí ùðä, úåçìú çééí áìúé îåâáìú. äçééí ÷öøé äîåòã ùì ,50 ,80, 100 àå 120 ùðä éäéå ðçìú äòáø, åàðå ðçéä çééí ììà äâáìú æîï, æåìúé îååú ëúåöàä îôâéòä çéöåðéú ëâåï úàåðä, èøåø àå àñåðåú èáò. åëì æä äåà ø÷ äà÷åøã äøàùåï áñéîôåðéú äèøðñôåøîöéä ä÷åñîéú ùì äàðåùåú.
áîàîø àðå éëåìéí ìøàåú, ëéöã äçå÷øéí áøàùåú ã"ø àèàìä îâãéøéí àú éòãéäí áöîöåí îøáé ëãé ìäøçé÷ òãåúí åìà ìäòìåú àì ôðé äùèç àú ääùìëåú äáìúé ðîðòåú ùì äèëðåìåâéä ùäí îôúçéí, ëâåï äàøëä áìúé îåâáìú ùì úåçìú äçééí, åäéëåìú ìúâáø àú äàãí îëì äáçéðåú ìôñâåú ùìà éàåîðå. äñéáä ùîãòðéí øáéí îñúéøéí àú äéòãéí àøåëé äèååç ùì îç÷øéäí åôéúåçéäí ðåáòú îúåê äéãéòä ùäâãøåú èøðñäåîðéñèéåú, îøçé÷åú ìëú ùì éòãéäí îåáéìéí ëéåí ìöéîöåí ú÷öéáé äîç÷ø åäôéúåç ùäí òåø÷ äçîöï äçéåðé ùì äîãò åäèëðåìåâéä. ìëï îä ù÷åøä ëàï, ùîúçú ìôðé äùèç úåôñú äèëðåìåâéä úàåöä àãéøä, ëàùø äîãòðéí òöîí îâãéøéí àú éòãéäí áöéîöåí ÷öø èååç åàôéìå áéåãòéï îñúéøéí àú ääùìëåú àøåëåú äèååç éåúø ùì ôòìí. åàéìå äú÷ùåøú, äöéáåøéåú, åáòöí ëåìí, òãééï ìà îòìéí òì ãòúí, ëìì ìà çùéí, ùîúçú ìàôí ëáø äçìä ììáåù úàåöä îñçøøú äîäôëä äèøðñäåîðéñèéú, äîäôëä ùòåîãú ìçåìì èøðñôåøîöéä áëì ä÷éåí äàðåùé, áàðåùåú åáàðåùéåú òöîä.
On a Scaffold in the Lab, Doctors Build a Bladder
The New York Times
By LAWRENCE K. ALTMAN
Bladders created in the laboratory from a patient’s own cells and then implanted in seven young people have achieved good long-term results in all of them, a team of researchers reported yesterday in a medical journal.
It takes about two months to grow the new bladder on a scaffold outside the body. After implantation, the engineered bladder enlarges over time in the recipient. The researchers say they expect that the new bladder will last a patient’s lifetime, but the longevity will be known only as the children grow older.
The hope is that someday the experimental reconstruction procedure will be standard for larger numbers of patients, including adults, and for those with other kinds of bladder damage.
A major advantage of his technique is that rejection cannot occur because the cells used to create a new bladder are from the patient, not from another individual. So an ultimate aim — still years off — is to develop the technique to grow a wide variety of other tissues, possibly even organs, to help relieve the shortage of donor organs available for transplanting, said the research team’s leader, Dr. Anthony Atala. He directs the Institute for Regenerative Medicine at Wake Forest University Baptist Medical Center in Winston-Salem, N.C.
Dr. Atala’s team’s online report in the journal Lancet concerned seven teenagers or younger children who had birth defects that led to urinary leakage and incontinence.
Dr. Atala, a urologist, said in a telephone interview that he implanted the bladders in all seven patients at the Children’s Hospital in Boston before he moved to Wake Forest in 2004. He said he began the research 16 years ago and implanted the first tissue-engineered bladder in 1999.
Although Dr. Atala has published on the technique, he said he reported none of the human cases until now because he wanted to wait for long-term results. The longest follow-up in Dr. Atala’s series of cases was more than six years, with an average of almost four years.
The seven patients who received the tissue-engineered bladders were born with a spinal defect known as myelomeningocele. The defect prevented complete closure of the spine, and impaired nerve function led to abnormal contraction of the bladder. The dysfunction can lead to a further cascade of events, including increased pressure in the bladder and damage to the kidneys.
For about a century, doctors have treated such patients by taking pieces of stomach or bowel to reconstruct the bladder.
But because that procedure involves disrupting nondiseased bowel tissue, it can lead to many direct and indirect complications. They include adhesions, in which tissue sticks together; secretions of mucus; and metabolic abnormalities like bladder stones.
For those and other reasons, “urologists agree that a need exists for a new replacement method,” said Dr. Steve Y. Chung of the Advanced Urology Institute of Illinois. He wrote a commentary in the same issue of The Lancet in which he called the new technique “promising.”
Urinary incontinence and other complications improved or did not occur in any of the seven patients, Dr. Atala’s team reported.
Despite the favorable findings, doctors in other medical centers need to do more cases with longer follow-up before the procedure can have wider application, Dr. Atala’s team and Dr. Chung said.
Dr. Atala said his team planned to start a larger clinical trial by the end of this year and to start another, which would include adults, by the end of 2007.
Beginning in 1990, in the early phases of his research, Dr. Atala had to learn how to grow human bladder cells in a laboratory. Then he had to develop a scaffolding as a way to reconstitute bladder tissue, starting with mice and rats and then moving up a ladder of larger animals, from rabbits to dogs.
In each of the seven human patients, Dr. Atala performed a biopsy to obtain cells from the inside lining of the bladder and from muscle.
The cells grew in cultures in a laboratory until there were enough to place on a bladder-shaped scaffold.
The scaffold was specially constructed to allow a composite of three layers of material. Two components were the bladder and muscle cells. A third contained biodegradable collagen from cattle and polyglycolic acid, a material that is used as mesh for hernia repair.
After the new bladder formed, in about seven to eight weeks, Dr. Atala removed a large portion of the patient’s bladder. Then he sewed the newly created tissue to what is known as the neck of the bladder and to the rest of the remaining portion of the patient’s natural bladder.
Dr. Atala said he had not analyzed what the procedure would cost if it became standard. He estimated that the materials and costs for workers would be $7,000 in each experimental bladder case but noted that the figure did not include costs for hospital stays and doctors’ fees.
Dr. Atala added that 80 researchers in his regenerative medicine institute at Wake Forest were trying to apply the scaffolding techniques to build new hearts, livers, kidneys, pancreases, nerves and other tissues. The ultimate aim, he said, is to reduce the need for donor organs and to avoid the immunologic dangers of rejection that come from transplanting someone else’s organs and tissues.
David Ish shalom comment: the ultimate aim, is not only to have a constant flow of non-rejectable organs and tissues, but a constant flow of non-aging organs to regenerate our bodies.




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