1 / 16

Alzheimer’s Disease

Alzheimer’s Disease. A Geriatric Epidemic. Alzheimer’s Disease. Alzheimer’s disease currently affects between two and four million Americans. Causes the degeneration of the nervous system over time Two basic forms: Early onset (under 65) Late onset (65+). History.

jase
Download Presentation

Alzheimer’s Disease

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Alzheimer’s Disease A Geriatric Epidemic

  2. Alzheimer’s Disease • Alzheimer’s disease currently affects between two and four million Americans. • Causes the degeneration of the nervous system over time • Two basic forms: • Early onset (under 65) • Late onset (65+)

  3. History • The first person to make a diagnosis of Alzheimer’s disease was Alois Alzheimer (1864-1915). Alzheimer made the diagnosis on a fifty-one year old named Frau Auguste D. • A Belgian pathologist found amyloid to be a component of the plaques found in the brains of those with Alzheimer’s in the 1930’s.

  4. Symptoms • Asking the same questions over and over again. • Repeating the same story, word for word, again and again. • Forgetting how to cook, or how to make repairs, or how to perform activities that were done with ease and regularity. • Getting lost in familiar surroundings, or misplacing household items. • Neglecting to complete everyday hygiene tasks. • Relying on someone else to make easy decisions.

  5. Treatment • The drug tacrine helps to slow the degeneration process, but it is costly and causes numerous side effects including the buildup of the toxic liver enzyme alanine aminotransferase. • Like tacrine, other drugs can only delay the inevitable. • To date there is no cure for Alzheimer’s disease.

  6. Alzheimer’s Physiology • Alzheimer’s disease is characterized by the presence of amyloid plaques and neurofibrillary tangles within the central nervous system. • The neurofibrillary tangles arrive as the result of defective tau proteins. • The plaques are derived from the buildup of β-amyloid protein, which in turn comes from amyloid precursor protein (APP).

  7. Tau Proteins • Healthy tau proteins help to support microtubules in neurons. • Mutations on exon 10 on the mRNA strand coding for tau gives rise to 3 tau isoforms with four microtubule binding site instead of the usual three. • This interferes with the tau’s ability to interact with the microtubule. Instead the free tau begins to interact with itself and begins building tangles.

  8. Neurofibrillary Tangle Formation

  9. β-Amyloid Plaques • β-Amyloid is made from post-translational amyloid precursor protein (APP). • Two different enzymatic pathways exist for APP. • Three different pathways exist for the site of APP digestion and the formation of β-amyloid. • The formation of intracellular pools of β-amyloid contributes to the plaques characteristic of Alzheimer’s.

  10. Enzymatic Pathways -Aβ40 vs. Aβ42

  11. Three Sites of APP Digestion

  12. Mutations Contributing to Plaques • Val717 mutation: increases ratio of Aβ42 to Aβ40 • Swedish mutation: mutation of amino acid 670 on APP from lysine to methionine along with amino acid 671 going from asparagine to lysine; increases use of β-secretase pathway • Presenilin mutation: increases ratio of Aβ42 to Aβ40

  13. Cell Death

  14. The Effect of Plaques on Action Potentials in the Nervous System

  15. Closing Comments • Current research is looking to telomerase for a possible cure for Alzheimer’s. • Pathologists also hope that stem cells may provide a cure. • Alzheimer’s not only affects the patients but their families as well. It is a sad slow course that leaves relatives emotionally exhausted.

  16. The End

More Related