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Type 1 Diabetes --
Advances in Treatments July 30, 2007 Experimental Therapy Reverses Type 1 Diabetes in Mice Preparatory work for human trials already under way, researchers say http://healthinfo.johnmuirhealth.com/healthnews/healthday/070730HD606783.htm - - - Excerpts: Researchers have accomplished what might be a cure of type 1 diabetes -- at least in mice --- and they're taking the first steps toward a human trial. ... Now, a three-drug regimen that not only stops the destruction of beta cells but also preserves the function of cells that receive and metabolize insulin has eliminated type 1 diabetes in labora- tory mice, said ... director of nonhuman primate research at the Transplant Research Center, Beth Israel Deaconess Medical Center in Bos- ton. ... "We stopped the progression of automimmunity. The animals could become normoglycemic," meaning they had normal levels of blood sugar, Koulmanda said. Another major discovery is that inflammation ap- pears to play a major role in type 1 diabetes, she added. In fact, one drug used in the treatment regimen reduced the inflammation of cells that metabolize insulin. "Basically, by blocking inflammation, we were getting the animals to be insulin-sensitive," Koul- manda said. Another drug successfully reduced the auto- immune destruction of beta cells, but that was not the key to reversing the disease, she said. Instead, success was linked to blocking inflam- matory processes that impair cells' responses to insulin. Some of the cells involved in insulin metabolism were found to be resistant to insulin's effects -- a common phenomenon seen in much more common, adult-onset, obesity-linked type 2 dia- betes, Koulmanda said. "This is the first time anyone has seen insulin-resistant cells in type 1 diabetes," she noted. A course of treatment lasting less than four weeks restored normal blood sugar function in the test mice. In contrast, mice that did not get the treatment died during that month-long period. Based on these promising results, the first work need to start a human trial of the regimen are about to begin ... The next step will be tests to ensure that the regimen is safe for human use. ... The fact that success was achieved in the mice trials with a relatively short course of treatment indicates that, for humans, "one might be able to use relatively brief periods of treatment to restore normal function," he said. - - - end excerpts - - - - - - Source: University of Central Florida Date: July 31, 2007 Insulin Grown In Plants Relieves Diabetes In Mice: Holds Promise For Humans http://www.sciencedaily.com/releases/2007/07/070730111638.htm - - - Excerpts: Science Daily — Capsules of insulin produced in genetically modified lettuce could hold the key to restoring the body's ability to produce insulin and help millions of Americans who suffer from insulin-dependent diabetes, according to Uni- versity of Central Florida biomedical researchers. ... Professor Henry Daniell's research team genet- ically engineered tobacco plants with the insulin gene and then administered freeze-dried plant cells to five-week-old diabetic mice as a powder for eight weeks. By the end of the study, the dia- betic mice had normal blood and urine sugar levels, and their cells were producing normal levels of insulin. Those results and prior research indicate that insulin capsules could someday be used to prevent diabetes before symptoms appear and treat the disease in its later stages, Daniell said. He has since proposed using lettuce instead of tobacco to produce the insulin because that crop can be produced cheaply and avoids the negative stigma associated with tobacco. ... Insulin typically is given through shots and not pills so the hormone can go straight into the bloodstream. In Daniell's method, plant cell walls made of cellulose initially prevent insulin from degrading. When the plant cells contain- ing insulin reach the intestine, bacteria living there begin to slowly break down the cell walls and gradually release insulin into the blood- stream. ... Though produced in lettuce, the insulin would be delivered to human patients as a powder in capsules because the dosage must be controlled carefully. If human trials are successful, the impact of Daniell's research could affect millions of dia- betics worldwide and dramatically reduce the costs of fighting a disease that can lead to heart and kidney diseases and blindness. ... Daniell's method of growing insulin in plants is similar to what he used for an earlier study to produce anthrax vaccine in tobacco. In the earlier study, which also involved mice, Daniell showed and the National Institutes of Health confirmed that enough safe anthrax vaccine to inoculate everyone in the United States could be grown inexpensively in only one acre of tobacco plants. ... - - - end excerpts - - - - - - Source: Johns Hopkins Medical Institutions Date: July 31, 2007 New Technique To 'See' And Protect Transplants Successful In Diabetic Animal Model http://www.sciencedaily.com/releases/2007/07/070730092608.htm - - - Excerpts: Science Daily — Researchers at Johns Hopkins have found a way to overcome a major stumbling block to developing successful insulin-cell trans- plants for people with type 1 diabetes. Traditional transplant of the cells, accompanied by necessary immune-suppressing drugs, has had highly variable results, from well- to poorly tolerated. Part of the problem, the Hopkins researchers say, is an inability to track the cells--so-called pancreatic beta cells--once they're inside the body. Now a new technique encapsulates the insulin- producing cells in magnetic capsules, using an FDA-approved iron compound with an off-label use, which can be tracked by magnetic reson- ance imaging (MRI). The product, tested in swine and diabetic mice, also simultaneously avoids rejection by the immune system, likely a major reason for trans- plant failure. The work will be published in Nature Medicine. "We're really excited because we can track where we put the cells and make sure their protective housing stays intact and that the cells don't move. This could solve the mystery of why current transplantation techniques work only for so long" ... Current experimental cell transplantation tech- niques are done "naked and blind," only lasting a short period of time ... The unprotected trans- planted cells are vulnerable to attack by the recipient's immune system, and researchers cannot see the cells to figure out why they stop making insulin after a while. To address both of these challenges, the re- search team captured beta cells in tiny porous capsules made from a mixture of alginate, a gooey material made from seaweed, and Fer- idex, a magnetic iron-containing material visible under MRI. They then used a machine that oozes droplets of this mixture to surround and encapsulate individual islet clusters each containing about 500 to 1,000 insulin-producing beta cells. Once the cells are encapsulated, the shell hardens, creating a "magnetocapsule" that measures less than 1/128 of an inch across. "They're tiny spheres with nano-scale pores just big enough too let the good stuff out but keep the bad from getting in" ... The openings in the magnetocapsule are so small that the body's immune system sentinels cannot reach and attack the transplanted cells. The team first transplanted magnetocapsules into the abdomens of mice engineered to de- velop diabetes. Blood sugar levels in the ani- mals returned to normal within a week and stayed that way for more than two months. In contrast, more than half of untransplanted dia- betic mice died, and the rest had very high blood sugar levels. To mimic human transplantation, the researchers then implanted magnetocapsules into the livers of swine with the help of MRI fluoroscopy, spe- cial reflective screens and a computer monitor that provide real-time imaging. The liver was chosen, rather than the usual pan- creatic home of beta cells, because it contains many blood vessels that can deliver insulin quickly to the rest of the body. ... The pigs underwent MRI and blood tests three weeks after magnetocapsule transplantation. MRI showed that the magnetocapsules remained intact in the liver, and blood tests revealed that the cells were still secreting insulin at levels con- sidered functional in people. "We hope that our magnetocapsules will make tissue-type matching and immunosuppressive drugs problems of the past when it comes to cell-based therapies for type 1 diabetes" ... - - - end excerpts - - -
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