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Archive - May 20, 2015

Multiple New Studies Contradict Earlier Findings on Utility of Bone Marrow Transplant in Rett Syndrome

Independent reproduction of other scientists' results is a cornerstone of solid research, but scientists are rarely recognized for successfully reproducing published findings, much less for demonstrating that scientific findings cannot be reproduced. However, failure to reproduce a finding may suggest doubt about the robustness of the original work, which carries implications for anyone looking to build on those findings. University of Iowa (UI) neuroscientist Dr. Andrew Pieper unexpectedly found himself in the position of contradicting seemingly promising results published in 2012 in the journal Nature that prompted a clinical trial for human patients. The original study from the laboratory of Dr. Jonathan Kipnis at the University of Virginia School of Medicine, conducted in mice, suggested that a bone marrow transplant from a healthy mouse could prevent the development of Rett syndrome--a severe neurodevelopmental disorder on the autism spectrum--and prolong the lifespan of the treated mice. The study also suggested that the bone marrow transplant arrested the disease because it restored normal microglia cells to the affected animals' brains. The finding was exciting because it suggested that an approach already used in medicine might provide a treatment for a devastating and incurable disease that strikes very young children. On the basis of this work, a clinical trial for bone marrow transplantation in patients with Rett syndrome was initiated at the University of Minnesota. Rett syndrome is caused by mutations in the X-linked MECP2 gene and affects about 1 in every 10,000 girls (it is most often fatal in boys at or near birth). Rett syndrome causes many disabilities, both intellectual and physical. Because many different MECP2 mutations can cause Rett syndrome, a wide range of disability, from mild to severe, can result from the disorder. Dr.

DNA Analysis Reveals Mysterious Absence of Indonesian Dogs in Madagascar

Their migration spanned half the globe and their culture was spread across the Pacific and Indian Oceans; but in Madagascar, the ancient Indonesians left behind a mystery. What happened to their dogs? In his latest research on the origins of dogs around the world, Dr. Peter Savolainen, a canine genealogy authority at Stockholm's KTH Royal Institute of Technology, set out to examine the genetic connection between dogs in Madagascar and the pets of ancient settlers from Indonesia. But to his team's surprise, no trace of Indonesian ancestry could be found among the island nation's dogs. Instead, Madagascan dogs all appear to trace their heritage entirely from Africa. Dr. Savolainen says that the findings offer little clue as to what happened to the Indonesian dogs that most likely sailed to Madagascar 1,500 to 2,000 years ago. "It's a mystery," Dr. Savolainen says of the study, which sampled DNA of 145 dogs from Madagascar and 184 from the African mainland. "We were surprised when we saw the results. We expected 100 percent or 50 percent ancestry from Indonesia—but it was zero percent." In ancient times, the expeditions of Indonesians typically included domestic animals, such as pigs, chickens, and of course, man's best friend. Along with their Austronesian culture and DNA, the Indonesians introduced their dogs' genes into populations wherever they settled. This canine DNA can still be found in Hawaii, Southeast Asia, the Cook Islands, and New Zealand, among other places. "Dogs, together with pigs and chicken, were important domestic animals in the Austronesian culture," Dr. Savolainen says.

Blockage of MCAM (Melananom Cell Adhesion Molecule) Shows Promise for Treatment of Multiple Sclerosis; Trial of Anti-MCAM Abs for Psoriasis Already Planned

A drug that could halt the progression of multiple sclerosis (MS) may soon be developed thanks to a discovery by a team at the CHUM (Centre Hospitalier de l'Université de Montréal) Research Centre and the University of Montreal. The researchers have identified a molecule called MCAM (melanoma cell adhesion molecule) (image), and they have shown that blocking this molecule might delay the onset of the MS and significantly slow its progression. The encouraging results, from in vitro tests in humans and in vivo tests in mice, were published online on April 13, 2015 in the Annals of Neurology. The title of the article is “MCAM+ CD8 T Lymphocytes Mediate CNS Inflammation.” "We believe we have identified the first therapy that will impact the quality of life of people with multiple sclerosis by significantly reducing the disability and the disease's progression," said Dr. Alexandre Prat, senior author of the study, Researcher at the CRCHUM, and Professor in the Department of Neurosciences at the University of Montreal. Dr. Prat also holds the Canada Research Chair in Multiple Sclerosis. MS is a neurological disease that is characterized by paralysis, numbness, loss of vision, and gait and balance deficits that lead to chronic disability. There is no effective cure. The disease particularly affects young adults in northern countries. In Canada, nearly 75,000 people have MS. The brain is normally protected from outside attacks by presence of the blood-brain barrier (BBB). The BBB prevents immune cells - lymphocytes - from entering the central nervous system. In people with MS, however, there is often leakage of the BBB. Two types of lymphocytes, CD4 and CD8, then find a way to cross this protective barrier.