Stories tagged Alzheimer's disease

Jan
18
2010

Retina as indicator of disease: This is not exactly what the optician will see when s/he examines your eye...that would be too easy.
Retina as indicator of disease: This is not exactly what the optician will see when s/he examines your eye...that would be too easy.Courtesy Cayusa
Alzheimer’s disease, that is. A technique developed by researchers at University College London (UCL), located on Repetitious Redundant Lane, allows your optician to not only find the proper lens prescription, but also screen you for early stages of Alzheimer’s disease. Their method takes advantage of the fact that the cells in the retina (the light-sensitive lining in the back of the eye) are direct extensions of the brain. As shown in the picture below, the retina is continuous with the optic nerve (also known as cranial nerve II), which then leads straight into the brain. The UCL researchers have found that the amount of retinal cell damage corresponds directly to the amount brain cell deterioration. They have also identified a particular pattern of retinal damage that is characteristic of Alzheimer’s patients.

Relation of the eyes to the optic nerve: Here you can see how closely connected the retinas (the back of the purple blobs) are to the optic nerve, and to the brain.
Relation of the eyes to the optic nerve: Here you can see how closely connected the retinas (the back of the purple blobs) are to the optic nerve, and to the brain.Courtesy William Vroman
The way to measure this damage simply involves using special eye drops that highlight dying retinal cells. Your optician can then observe the extent and configuration of the deterioration. Research shows that cells start to die ten to 20 years before Alzheimer’s symptoms start to surface, so this procedure could be used to diagnose the disease in its early stages. This test would be quick, easy, and inexpensive, and being able to detect the disease early would allow doctors to treat, and possibly reverse the symptoms of this disease.

So far, the researchers have only tested this technique on mice, but they will start to test human subjects in the near future. According to UCL, you might be able to receive this test within the next five years. However, there are some reasons that people might not want to screen themselves. There is fear that insurance companies could increase the premiums of middle aged people who test positive. There are also people who would just rather not know they may have this devastating disease in their future. How about you? Would you want to know?

Apr
06
2009

What if your doctor could prescribe a pill that would erase any and all of your worst memories instantly?!

Rather than reliving it every single day, you could simply forget the time in 6th grade when you farted while doing sit-ups in gym class, and the day that your beloved cat Pookie was run down by your mother's Buick, and the boyfriend who broke your heart when he ran off to join the circus.

Rather than dwelling on bad memories, you could forget about them and move on to live the rest of your happy sunshiny life.

While it may sound like the plot of a certain indie film, brain scientists at a lab in Brooklyn are working on a scientific breakthrough that may make all of this possible. They've discovered that a chemical in the brain called PKMzeta acts like a speed dial to all of our worst (and best) memories. When a drug called ZIP is injected directly into the brain, memories are blocked and viola! No more dwelling on the painful, embarrassing, traumatic past.

Nevermind that it isn't quite that simple, or that this method has only been tested on rats, or that it involves a chemical being injected directly into the brain. It's from Brooklyn, so you know it'll be on the gifts & novelties table at Urban Outfitters just in time for the holidays. In fact, I can already see the marketing campaign involving lots of waifish models who apparently forgot to eat.

While this kind of 'made to order' miracle memory eraser won't be hitting the shelves anytime soon, there is a whole lot of money being spent on research that aims to better understand how memory works inside our brains. The reason that scientists want to know how memory works is that memory is so important to our emotions, our ability to learn, our spatial knowledge, our motor skills and much much more. When it isn't working as it should be, all kinds of problems can result.

For some people, painful and traumatic memories can wreak havoc on their emotional and social lives. Post-Traumatic Stress Disorder and Depression are examples of diseases that involve the unconscious recall of frightening or upsetting memories. If these memories could be blocked, patients might experience a dramatically improved quality of life. Bad habits are also tied to our memories, since addictive behaviors are learned. If memories of experiences with drugs and alcohol could be blocked, some addicts might stand a better chance of recovery. And for those who suffer from Alzheimer's or Dementia, improvements in the understanding of memory could lead to new methods of memory enhancement, helping to reduce the impact of these diseases.

While plenty of good things will come from this kind of research, it also raises ethical questions. Any drug that can dramatically improve or block selected parts of our memory will inevitably find a commercial market among people who may not suffer from any disease at all. Students who can afford them might start taking memory enhancing drugs right before an exam, criminals might use memory blockers to short circuit the moral questions that arise from their behavior and ordinary people might be tempted to use memory blockers to forget painful or embarrassing moments, rather than learning from them.

To top it all off, since our good and bad memories are not neatly sorted for doctors to target, erasing painful memories would probably mean getting rid of some of the good ones as well. Sometimes it's hard to tell which is which, since good or bad, your memories make you who you are today.

Source: New York Times

An apple a day keeps the doctor away, but a cup of coffee may help, too. Researchers have found that caffeine blocks the damage that cholesterol does to the body, and may lower the risk of Alzheimer's and dementia.

Oct
15
2007

A slice of a brain infected with Alzheimer's: The disease shrinks brain tissue and leads to severe memory loss. Photo by AJC1 at Flickr.com
A slice of a brain infected with Alzheimer's: The disease shrinks brain tissue and leads to severe memory loss. Photo by AJC1 at Flickr.com

Researchers at Stanford have developed a blood test which, in early trials, has been 90% accurate in identifying patients with Alzheimer’s disease. The test is also 80% accurate in predicting who will get Alzheimer’s in the next 2 to 6 years.

The article notes:

At present, treatments for Alzheimer's disease are not very effective, so some people might not want early notification that they have an incurable ailment. But other people might want it.

What do you think? If you had an incurable disease that would not start to manifest itself for several years, would you want to know?

Jul
09
2007

Alzheimer's sniffer?: Are declining abilities to sense certain smells a sign that Alzheimer's disease is coming? Some researchers think it might be a possibility.
Alzheimer's sniffer?: Are declining abilities to sense certain smells a sign that Alzheimer's disease is coming? Some researchers think it might be a possibility.
While lost memories are the most evident sign of full-blown Alzheimer’s disease, new research is showing that our nose may be able to detect the onset of the dreaded condition.

A new study is targeting our sense of smell as being one of the first things to be impacted by Alzheimer’s. An easy scratch-and-sniff test might be the key to discovering the start of the condition in a person.

Through a five-year study, 150 people with memory loss had their noses’ effectiveness tested and compared with similar results in 63 healthy adults. The test was to have all of them identify ten specific smells – lemon, strawberry, smoke, soap, menthol, clove, pineapple, natural gas, lilac and leather.

What the researchers found was that the same percentage of people who had difficulty identifying the smells matched closely to the same percentage of people who develop Alzheimer’s through research that’s conducted by using MRI scans to measure brain volume loss.

While there’s not a direct correlation between the smell test and brain testing, researchers think it could be a good tool for doctors to use in monitoring the possible start of Alzheimer’s. Patients who do poorly on the smell test could go through more extensive testing that might find some early signs of the disease.

And while there is no cure, there are drugs and treatments that can slow down the progress of Alzheimer’s in the body. The sooner signs of the condition are discovered, the quicker slow-down action can be taken.

How does this all smell to you? Share your thoughts here with other Science Buzz readers.

Jun
27
2007

Have you ever wondered why medicine seems to be so ineffective in dealing with many neurological diseases? We have treatments and drugs to combat disorders throughout the rest of the body, but diseases like Alzheimer’s or Parkinson’s remain difficult to treat.

A team of scientists recently created a drug that can cross the blood-brain barrier to treat neurological diseases in mice. Capillary walls in the brain are very effective at controlling which molecules can pass into the spaces between neurons. This protects the brain from potentially harmful chemicals in the blood. Until now, this also prevented much needed medicines from penetrating into an affected brain!

But, wait. If the brain is so great at preventing molecules from penetrating capillary walls, how do diseases get through? Some viruses, such as rabies, are able to trick the barrier into letting them through. Researches attached one of these trickster molecules from rabies onto a drug, and found that the drug was delivered through the capillary wall and into the brain.

In this study, scientists infected mice with Japanese encephalitis. Medicine delivered using the new method kept 80 percent of diseased mice alive for 30 days, while all of the untreated mice died.

While researchers tested this technique only on mice, soon this could provide huge benefits to humans. The drug used to combat encephalitis in mice uses a kind of RNA, short-interfering RNAs (siRNAs), that block the activity of a gene. This type of RNA can be custom tailored to target almost any disease-causing gene or protein. Combined with the molecules that can break through the blood-brain barrier, scientists could more effectively treat Alzheimer’s, Huntington’s, Parkinson’s and many more neurological diseases.