Newly discovered variants in a key gene may indicate a modest risk for late-onset Alzheimer's disease.
By Jennifer Chu
Scientists who have studied the genetic makeup of several large and ethnically diverse populations have discovered another gene that may be a modest risk factor for Alzheimer's disease.
The gene, called SORL1, may be involved in the development of late-onset Alzheimer's, the most common form of the disease, which occurs after age 65 and accounts for 90 percent of Alzheimer's cases today.
Researchers say determining how SORL1 and other genes cause or influence Alzheimer's disease could open up new avenues for diagnosis and treatment.
"Ultimately, one wants to be able to profile an individual for genes and variants within genes … that may give an understanding of the disease process," says Lindsay Farrer, chief of the genetics program at Boston University. "And secondly … therapies can be tailored to an individual's profile. We're still in the early days of filling in the pieces of that puzzle."
Farrer and his colleagues zeroed in on the gene SORL1 thanks to previous studies that revealed a key biological pathway in Alzheimer's.
Today, most researchers agree that the disease is caused by a buildup of amyloid plaque in the brain. The chain of events that produces this plaque begins with a normal protein, amyloid precursor (app).
When this protein comes in contact with a certain type of enzyme called presenilin, that enzyme cuts, or cleaves, app into a more toxic peptide, amyloid-beta. This sticky protein fragment clumps together to form amyloid plaques, killing nerve cells. For years, scientists have looked for ways to stem this cascade. SORL1, according to Farrer, could play a pivotal role in the disease's pathway.
Through previous cellular experiments, Farrer and other research groups found that SORL1 is essentially a trafficking molecule.
Under normal conditions, SORL1 directs app away from what researchers call the "forbidden zone"--where the enzyme presenilin resides--thus preventing the protein from being sliced apart to form toxic plaque.
"It's like a delivery boy or carrier protein that delivers the amyloid precursor to various parts of the cell," says Samuel Gandy, director of the Farber Institute of Neurosciences and vice chair of the Alzheimer's Association's Scientific Advisory Council.
"It sits at the crossroads of a cell and tells proteins where to go."
In a five-year study, published in the February edition of Nature Genetics, Farrer, along with colleagues from the University of Toronto, Columbia University, and the Mayo Clinic, analyzed DNA samples from 6,000 people across nine different groups.
These groups included Northern-European Caucasians, Caribbean Hispanics, Israeli Arabs, and African Americans.
Some groups were selected based on family history: two or more members had the disease. Others were selected based on sibling pairs: one sibling had Alzheimer's, the other didn't.
The rest had no family linkage to the disease. All cases were compared with controls: genotypes of people without Alzheimer's.
__________________ Michael the Archangel
m
He was the sort of person who stood on mountaintops during thunderstorms
in wet copper armour
shouting
"All the Gods are bastards." Terry Prattchet
Last edited by Michaelangelica; 01-16-2007 at 12:18 AM.
Lyme disease (LD) is a tick-borne zoonosis caused by the spirochaete bacterium, Borrelia burgdorferi. Since the disease was first recognised in 1975 it has become the most frequently reported human tick-borne infection worldwide. It has been reported from every continent (except Antarctica) although doubt remains as to whether it occurs in the southern hemisphere in general, and in Australia in particular
Cutting Edge - a series that explores medicine's newest hypotheses
Is there an association between β-amyloid in Alzheimer's disease and herpes simplex virus type 1?
In the latest issue of Medical Hypotheses there is an interesting article Senile plaques in Alzheimer’s diseased brains: Possible association of β-amyloid with herpes simplex virus type 1 (HSV-1) L-particles by E.M. Kammerman, D.M. Neumann, M.J. Ball, Walter Lukiw and J.M. Hill of Louisiana State University Health Sciences Center, New Orleans that begins:
"The characteristic insoluble, senile (neuritic) plaques found extracellularly in brains of patients with Alzheimer’s disease (AD) contain the fibrillar form of β-amyloid (Aβ42).
A substantial proportion of autopsied elderly brains have demonstrated DNA evidence of herpes simplex virus type 1 (HSV-1) infiltration. HSV-1-infected cells produce significant quantities of non-infectious, non-DNA-containing light particles (L-particles) comprised of viral envelope and tegument proteins. HSV-induced L-particles can be exocytosed out of their host cells."
__________________ Michael the Archangel
m
He was the sort of person who stood on mountaintops during thunderstorms
in wet copper armour
shouting
"All the Gods are bastards." Terry Prattchet
In this month's Cosmos science magazine there is an article by
Ramez Naam, one of the creators of internet explorer and outlook
(good issue on the brain SEE: - )
He talks about some research being done by Mark Tuszynski and co on NGF "nerve growth factor" a brain chemical that triggers the growth of neurons. When this was enhanced genetically (?) the progress of Alzheimer's was reduced by a factor of three. This looks like being a very promising way to go in treating the disease.
However there are other implications; NGF therapy can give rats and mice better than normal memory (University of Rochester NY Tim Tulley; and Eric Kandel). mice can learn 2-5 times quicker than normal mice.
Namm says this therapy may lead us to drugs that can not only teach us how memory works but will enable smarter faster learning doctors, engineers scientists etc
Namm talks about the ethical issues involved; but I say bring it on. I have always had a bad memory. give me the pill!
There are a few herbs that are said to enhance memory. I wonder if they contain drugs that enhance NGF? They include: gotu kola (Hydrocotlyte asiatica) , (Red) sage (Salvia officinalis var?) especially when in flower; BBC NEWS | Health | Sage herb 'can boost memory' Rosemary and Ginseng (probably just help blood flow to brain, altough ginseng probably also promotes testosterone) Ginkgo biloba Wiley InterScience :: Session Cookies Galanthus nivalis
This would be an interesting paper to read has anyone access to it
Quote:
Quote:
Quote:
Plants with traditional uses and activities, relevant to the management of Alzheimer's disease and other cognitive disorders
__________________ Michael the Archangel
m
He was the sort of person who stood on mountaintops during thunderstorms
in wet copper armour
shouting
"All the Gods are bastards." Terry Prattchet
Last edited by Michaelangelica; 02-24-2007 at 09:34 PM.
And has been consistently touted to help reduce the risk of Alzheimer's. Go put on your running shoes and hit the track!
__________________ Logic
The art of thinking and reasoning in strict accordance with the limitations and incapacities of the human misunderstanding.
--Ambrose Bierce, The Devil's Dictionary
Updated 28 January 2004
BDNF and Alzheimer's Disease—What's the Connection?
By Nicole C. Berchtold and Carl W. Cotman
Live Discussion held 25 November 2003. See Transcript.
Why Is BDNF interesting?
The protein brain-derived neurotrophic factor (BDNF) has been the focus of intense interest in the Alzheimer's field for a number of years.
BDNF belongs to the neurotrophin family of growth factors and affects the survival and function of neurons in the central nervous system, particularly in brain regions susceptible to degeneration in AD.
BDNF improves survival of cholinergic neurons of the basal forebrain, as well as neurons in the hippocampus and cortex.
This discovery kindled hope in the early 1990s that Alzheimer's could be slowed or halted if brain levels of BDNF could be increased.
The idea gained support with the observation that BDNF gene activity and protein levels are reduced in AD brains.
Been drinking herb tea all day since last post
__________________ Michael the Archangel
m
He was the sort of person who stood on mountaintops during thunderstorms
in wet copper armour
shouting
"All the Gods are bastards." Terry Prattchet
Last edited by Michaelangelica; 02-25-2007 at 03:07 AM.
Well yes Racoon. I do agree because as unfortunate as life can get my grandfather(on my dad's side) got hit on the head so he had amnisia for a while. After that he went to a hospital and for paying the fees his daughters asked for the money and bugged him so much he went wacko or, in more scientififc terms, he got alzeihmers I think. We're not sure because all he remembers is money and his wife which,sadly enough, thinks is his mother.
Please tell me if this is alzeihmer's or this is something else. If so, tell me what it is and what it does.
P.S.- He's really clumbsy like me but I don't think it's that whole Third- Generation Problems. My brother will be able to figure what's happening to him and how to fix it(he's a medical wiz).
__________________
"Pain is the only thing in this world that matters. Peter was right, because if you didn't the power to cause pain then you are prey to those who can. Pain is the strongest thing ever"
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~
Funny I have never been able to run, a 100yd sprint maybe, but never anything long.
I think there are different exercises that can accomodate anyone's preferences or body type. I just like running, I guess. Always have since I was a kid, although I wasn't able to train more until the last year. Since then, it's been a regular part of my exercise.
I know a little bit about them. I'm not very knowledgeable about their exact physiological effects on neurons, but from what I've gleaned, they're very important and work in concert to help neurons grow, stay alive, and improve function. Where the concentration of these neural growth factors is high, neurons act more healthy, resist damage better, fire stronger impulses, and grow more dendrites and control them better--which all translates into better health and performance for the brain.
Where they took skin cells, genetically modified them to produce extra NGF, then implanted them in the brains of people with Alzheimer's disease. The treatment helped to slow the degeneration.
I came across more information about the relationship between neural growth factors, learning, exercise, etc. when I was trying to check for natural methods to relieve depression, which I was suffering at the time. (I feel quite fine now, though. Much more like my old self and never so good. ) It seems that many things which ail the brain may work through common mechanisms or may stem from common causes.
One more strange thing about NGF is that it's also found in saliva. It gives a whole new meaning to the old phrase to "lick one's wounds."
So there might be a few ways of reducing the risk or getting around it. Some populations don't seem to have high rates of Alzheimer's disease, and it may be due to diet and habits rather than genetics. I think genetics does play a part, but exercise, diet, and habits maybe more so. I don't think the population genetics of Western countries has changed all that much in a few generations, but our habits, diets, and fitness demonstrably have, and perhaps it's no coincidence that risk factors for Alzheimer's are many of the same risk factors for heart disease, strokes, or other forms of dementia.
I'm not a neuroscientist or doctor, though, so don't take my speculation for fact. I know very little about the brain, although neuroscience interests me a lot. Someday I'll get some neuroscience textbooks and learn more about it straight from the sources.
Thank you for the article on BDNF as well! Learnin', learnin', learnin'. Gotta crank out more NGF, BDNF, and others to accomodate that new info.
__________________ Logic
The art of thinking and reasoning in strict accordance with the limitations and incapacities of the human misunderstanding.
--Ambrose Bierce, The Devil's Dictionary
In the murky waters of an inconspicuous stream in a remote area of Wyoming, researchers detail the potential impact that an introduced fish, the white sucker, could have on the evolutionary biology of fishes. Read » | 0 comments
A new paper appearing July 20 in the Astrophysical Journal explains why this outer ring stands out. According to the authors, the red color highlights a zone where organic molecules called polycyclic aromatic hydrocarbons, which are present throughout most of the galaxy, suddenly disappear. Read » | 0 comments
Alzheimer's? Why? 
Re: Alzheimer's? Why? 
