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    Alzheimer’s disease found to be a diabetic disorder of the brain

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    Carol
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    Alzheimer’s disease found to be a diabetic disorder of the brain

    Post  Carol on Sat Nov 19, 2016 9:05 am


    Alzheimer’s disease found to be a diabetic disorder of the brain
    http://scienmag.com/alzheimers-disease-found-to-be-a-diabetic-disorder-of-the-brain/

    Researchers at Tohoku University have found a promising treatment for Alzheimer's disease, by noticing a similarity in the way insulin signaling works in the brain and in the pancreas of diabetic patients.

    "In the pancreas, the Kir6.2 channel blockade increases the insulin signaling, and insulin signaling decreases the blood glucose levels," says Dr. Shigeki Moriguchi. "In the brain, insulin signaling increases the acquisition of memory through CaM kinase II activation by Kir6.2 channel blockade."

    The research group, led by Dr. Moriguchi and Professor Kohji Fukunaga of the Graduate School of Pharmaceutical Sciences, thus concluded that Alzheimer's disease can be described as a diabetic disorder of the brain.

    Memantine, a drug widely used to treat Alzheimer's disease, is a well known inhibitor of the N-methyl-D-aspartate (NMDA) receptors that prevent excessive glutamate transmission in the brain. Researchers have now found that memantine also inhibits the ATP-sensitive potassium channel (Kir6.2 channel), improving insulin signal dysfunction in the brain.


    _________________
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    It is the flash of a firefly in the night, the breath of a buffalo in the wintertime. It is the little shadow which runs across the grass and loses itself in the sunset.

    With deepest respect ~ Aloha & Mahalo, Carol
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    Carol
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    Boosting immunity in older adults: UA unmasks new infection-fighting T cells

    Post  Carol on Sat Nov 19, 2016 9:08 am

    Boosting immunity in older adults: UA unmasks new infection-fighting T cells
    http://scienmag.com/boosting-immunity-in-older-adults-ua-unmasks-new-infection-fighting-t-cells/

    TUCSON, Ariz. – Sixty-five is the age when many people retire, kick back and take it easy. And so it often is with the human immune system.

    After years of fending off influenza and other infectious diseases, the immune system gradually starts to lose its oomph for fighting infection. As a result, viruses, bacteria and other microbial intruders are a common killer of adults 65 and older.

    New findings from a study led by the University of Arizona Health Sciences Department of Immunobiology show it may not have to be that way.

    The study examined blood samples from 92 volunteers, age 21 to 97. Researchers focused on a subset of T cells – white blood cells that fight infection and decrease in number as adults age – specifically, T cells labeled “naïve” because they have not yet been exposed to a virus or other infection.

    “When there is an infection, like an influenza virus, for example, a small cohort of these naive T cells – only those that have special molecules on their surface that will bind to fragments of the influenza – are deployed in a very targeted manner,” said Janko Nikolich-Žugich, MD, PhD, head of the Department of Immunobiology and Elizabeth Bowman Professor of Medical Research at the UA College of Medicine – Tucson, and the study’s principal investigator.

    These deployed naive T cells then become effector T cells, he said. Unlike the naive cells, which cannot harm the virus, effector cells are “armed” and able to clear the virus using antiviral molecules they now make. “Once they have done away with the infection, most of the effector T cells will die, but a substantial number will survive and become ‘memory’ cells,’ which will remember and fight off an infection, if and when it recurs,” Dr. Nikolich-Žugich said.

    The breakthrough came when the researchers, focusing on navie T cells, discovered that when stimulated with pieces of virus, a portion of the cells began making interferon-gamma, a powerful anti-viral molecule.

    They found that among these naive cells – which now looked functionally more like memory cells – many were marked to attack cytomegalovirus (CMV), a type of herpes virus that infects most people and is carried for life without harm, kept in check by a highly functioning immune system, but devastating to those with suppressed immune systems, including older adults.

    These naive T cells are “a new ‘flavor’ of naive cells that are not completely naive,” Dr. Nikolich-Žugich said. “So our new discovery is that there is more diversity than we realized within the naïve cells, and that some already have committed to dealing with CMV and other really persistent infections, and others are really, truly naive.”

    Dr. Nikolich-Žugich and his colleagues have named the “new flavor” of T cells “T memory cells with naive phenotype.”

    One next step, Dr. Nikolich-Žugich said, is to count the number of these cells in an individual’s blood sample, which may indicate the fitness of that person’s immune system.

    Another step will be to vaccinate some of the people in the study cohort and monitor these special T memory cells before and after vaccination, to test whether it can predict responses to vaccination. In addition to influenza vaccine – which confers more protection on younger adults than older adults – Dr. Nikolich-Žugich would like to try a vaccine given to prevent Japanese Encephalitis Virus – a cousin of West Nile Virus, which belongs to the same group as the Zika and Dengue viruses.

    “Giving a vaccine that most people have not been given in their lifetimes will give us a better idea of how fit is their immune system,” he said.

    “The biggest challenge for us going forward is to measure the status of the immune system, including these new cells, and actually show, in an average person, if you are below a certain level of a T cell population, or a certain cytokine or a certain antibody, what is your risk of infection or poor response to vaccination. And if you are at risk, how can we work to help you and your immune system.”


    _________________
    What is life?
    It is the flash of a firefly in the night, the breath of a buffalo in the wintertime. It is the little shadow which runs across the grass and loses itself in the sunset.

    With deepest respect ~ Aloha & Mahalo, Carol

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