News reports of research into Alzheimer's disease July - December 2004
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There's a glossary of terms used in Alzheimer's research.
Disclaimer:
This section began as an offshoot of my
gathering of news items about memory. I am not a medical expert. My
background is in psychology. The information I have gathered here should
not be taken as providing any advice.
December
Pilot study points to healing power of turmeric
A study using genetically engineered mice has found that those mice on
a diet rich in curcumin (the yellow pigment in the curry spice turmeric)
developed 85% few Alzheimer’s plaques then the control group. Curcumin
has antioxidant, anti-inflammatory, and cholesterol lowering properties,
and has long been used in India as treatment for a variety of ailments.
A human trial involving 33 Alzheimer's patients will soon commence.
The study was reported online December 7 in the
Journal of Biological Chemistry.
Full reference
A copy of the full paper can be found on the Journal of Biological
Chemistry Web site athttp://tinyurl.com/5bzbs
http://www.eurekalert.org/pub_releases/2004-12/potn-usn122804.htm
http://www.sciencentral.com/articles/view.htm3?article_id=218392455
a name="Smell">Smell test to help early diagnosis
One of the first types of memory affected by Alzheimer’s is olfactory
memory – our database of smells. Researchers have now developed a simple
scratch-and-sniff test that may enable Alzheimer’s to be detected in its
very early stages. On the basis of a five-year study tracking 150 people
with mild memory loss and Alzheimer's disease and 63 healthy adults, 10
specific odors proved to be the best predictors for Alzheimer's Disease:
strawberry, smoke, soap, menthol, clove, pineapple, natural gas, lilac,
lemon and leather. The test takes only 5 to 8 minutes, and seems to have
comparable predictive ability as detailed memory and neuropsychological
testing.
The findings were presented at the 2004 meeting of the American College of
Neuropsychopharmacology.
http://www.sciencentral.com/articles/view.htm3?article_id=218392445
http://www.eurekalert.org/pub_releases/2004-12/g-sfl121004.htm
Findings show how toxic proteins rob Alzheimer's patients of memory
Researchers have discovered a molecular mechanism that could explain
why the brain damage in early Alzheimer's disease results in memory loss
and not other symptoms such as loss of balance or tremors. Toxic
proteins called "amyloid ß-derived diffusible ligands" (ADDLs) — first
discovered last year — have been found to specifically attack and
disrupt synapses, rather than the neurons themselves. By so doing they
damage the neuron’s ability to communicate with other neurons. Moreover,
the ADDLs target specific synapses — those where there is a gene linked
to memory that is normally expressed. The attack disrupts the normal
expression of the gene. The finding brings hope that the damage is
reversible. ADDls are a form of amyloid beta, but differ from the
better-known amyloid fibrils known as plaques, that are a hallmark of
Alzheimer’s.
Results were published in the November 10 issue of the
Journal of Neuroscience.
Full reference
http://www.eurekalert.org/pub_releases/2004-12/nu-fsh120104.htm
Rolipram - a potential new treatment
In a mouse study, a phosphodiesterase 4 inhibitor, rolipram, was found
to improve memory in both long-term potential and contextual learning.
Rolipram's protective effect is due to its ability to modify gene
expression, making brain synapses more resistant to the insult caused by
the accumulation of Ab. The beneficial effect of rolipram treatment was
found to extend for at least 2 months after the end of one course of the
treatment, and was more effective in the later stages of the disease.
The study appeared in the December 1 issue of the
Journal of Clinical Investigation.
Full reference
http://www.eurekalert.org/pub_releases/2004-12/joci-r-a111804.htm
Keeping blood pressure & cholesterol low may help some dementia patients more than Alzheimer's drugs
A comprehensive review of all recent medical studies on mixed dementia,
vascular dementia and Alzheimer's suggests that efforts to treat
cardiovascular risk factors, especially high blood pressure, may be more
effective for many than memory drugs in protecting brain function.
The study was published in the December 15 issue of the
Journal of the American Medical Association.
Full reference
http://www.eurekalert.org/pub_releases/2004-12/uomh-thy120904.htm
Fewer calories may slow Alzheimer's
Restricting the diets of genetically engineered mice by 40% over 4
weeks reduced the build-up of plaques in the brain that are linked to
Alzheimer's disease by 50%. It remains to be seen whether such dietary
changes would similarly affect humans. Researchers are now looking to
isolate the specific factors of the diet restriction which are
important.
The study was published 25 November in the online version of
Neurobiology of Aging.
Full reference
http://www.eurekalert.org/pub_releases/2004-12/uosc-fcm121404.htm
November
New type of Alzheimer's drug on trial
A clinical trial is commencing to test the effectiveness of a new type
of drug, called Alzhemed, that attacks amyloid. The trial will last 18
months and will enroll about 950 Alzheimer's patients with a
mild-to-moderate form of the disease, from centers around the United
States and Canada. The drug actually physically combines with amyloid to
prevent plaque formation, and is also expected to inhibit the
inflammatory response associated with amyloid buildup in Alzheimer's.
http://www.eurekalert.org/pub_releases/2004-11/tju-jns110204.htm
Pet scans detect brain differences in people at risk for Alzheimer's
Brain imaging of 32 participants, mostly in their 60s and 70s, has
found clear differences in brain function between healthy people who
carry a genetic risk factor for Alzheimer's disease and those who lack
the factor. More research is needed before it's known for certain if the
difference is an early sign of Alzheimer's.
The study appeared in the Nov.-Dec. 2004 issue of the
American Journal of Geriatric Psychiatry.
Full reference
http://www.eurekalert.org/pub_releases/2004-11/cuco-psd111904.htm
Reduced risk of institutionalization in patients with dementia
A study of 596 patients from 7 countries found that dementia patients
receiving long-term treatment with REMINYL (more than 36 months) may be
able to stay at home for longer compared to those receiving treatment
for shorter periods of time. Experts believe the long-term clinical
efficacy of galantamine may be because as well as enhancing levels of
the neurotransmitter acetylcholine, it also (unlike other treatments),
has a modulating effect on the brain's nicotinic receptors, which is
believed to increase their effectiveness. Nicotinic receptors are
thought to play a key role in attention, memory and learning.
The results of this study were presented at the 17th European Congress of
Neuropsychopharmacology, Stockholm, Sweden.
Reference
http://www.eurekalert.org/pub_releases/2004-11/rc-rro110904.htm
Compound in apples may help fight Alzheimer's disease
Researchers are recommending that apples may be a particularly
beneficial food to protect against Alzheimer’s. A study that exposed
groups of isolated rat brain cells to varying concentrations of either
quercetin or vitamin C supports the theory that quercetin protects
against cellular damage. A particularly good source of quercetin is
apples — mainly in the skin. In general, red apples tend to have more of
the antioxidant than green or yellow ones. Other foods containing high
levels of quercetin include onions, which have some of the highest
levels of quercetin among vegetables, as well as berries, particularly
blueberries and cranberries.
The study appeared in the December 1 issue of the Journal of
Agricultural and Food Chemistry.
http://www.eurekalert.org/pub_releases/2004-11/acs-ia111604.htm
October
Tea may protect against Alzheimer’s
A study investigating the properties of coffee and green and
black tea has found that both green and black tea inhibited the
activity of enzymes associated with the development of Alzheimer's
Disease (acetylcholinesterase and butyrylcholinesterase), but coffee
had no significant effect. Green tea also obstructed the activity of
beta-secretase, which plays a role in the production of protein
deposits in the brain which are associated with Alzheimer's disease,
and continued to have its inhibitive effect for a week, whereas
black tea's enzyme-inhibiting properties lasted for only one day.
The findings are published in the August issue of
Phytotherapy Research.
Full
reference
http://www.eurekalert.org/pub_releases/2004-10/uonu-tci102504.htm
Inhibiting Apolipoprotein E possible means of therapeutic intervention
It has been known that the inflammatory protein ApoE can speed the
buildup in the brain of amyloid plaques,but the mechanism has not been
known. A mouse study found ApoE is responsible for converting harmless
amyloid-beta into the toxic fibrous deposits known as filamentous
amyloid. This process is needed to damage nerve cells in parts of the
brain controlling memory and cognition. Mice with Alzheimer's disease
showed memory deficits only when the ApoE gene was present. The study
suggests that preventing ApoE from acting upon amyloid-beta may prove to
be an effective means of therapeutic intervention.
Two papers have been published in the October 2004 issues of the
Journal of Alzheimer's Disease and the
Neurobiology of Aging. Full reference
1,
2
http://www.eurekalert.org/pub_releases/2004-10/uosf-rur102904.htm
Blood pressure drugs may slow deterioration of Alzheimer's
A study involving 162 people in Japan living in long-term care
facilities with mild to moderate Alzheimer's disease and high blood
pressure has found that certain blood pressure drugs may slow the
deterioration of Alzheimer's disease. The results, while interesting,
will need to be replicated in carefully controlled, randomized, blinded
studies
The study was published in the October 12 issue of
Neurology.
Full reference
http://www.eurekalert.org/pub_releases/2004-10/aaon-bpd100404.htm
Researchers identify brain protein that halts progression of Alzheimer's
Researchers have identified a protein in the brain, "transthyretin,"
that halts the progression of Alzheimer's disease in human brain tissue
by blocking beta-amyloid.
The findings were presented on October 26 at the 34th annual meeting of
the Society for Neuroscience in San Diego, Calif.
http://www.eurekalert.org/pub_releases/2004-10/nioe-rib102504.htm
Anti-cholesterol drug treats Alzheimer's disease in mice
A drug that jams a key enzyme regulating cholesterol (CP-113,818) has
been found to drastically reduce the levels of amyloid plaque in
genetically engineered mice. The drug has not been tested in clinical
trials, but another ACAT inhibitor, avasimibe, is now in final clinical
trials as a treatment for vascular disease and atherosclerosis.
The study was reported in the October 14 issue of
Neuron.
Full reference
http://www.eurekalert.org/pub_releases/2004-10/cp-adt101204.htm
September
Omega-3 fatty acid may prevent Alzheimer's disease and slow its progression
A study using genetically engineered mice has shown that a diet high in
the omega-3 fatty acid DHA helps protect the brain against the memory
loss and cell damage caused by Alzheimer's disease. Cheap sources of DHA
include coldwater fish, like salmon, halibut, mackerel, sardines and
herring. These fish consume algae, which is high in DHA. Because these
fishes' oiliness makes them absorb more mercury, dioxin, PCP and other
metals, however, a less risky yet more costly strategy is to consume
fish oil or purified DHA supplements made from algae. Other options
include DHA-rich eggs laid by chickens that eat DHA-supplemented feed.
The paper appeared in the September 2 issue of
Neuron.
http://www.eurekalert.org/pub_releases/2004-09/uoc--ddp082604.htm
New gene therapy technique
A new technique using gene therapy to deliver nerve growth factor into
regions of the brain where neurons are degenerating is being trialed in
a two-year study. The technique, which requires neurosurgery to inject
the drug precisely where it is required (the basal forebrain), uses a
new drug called CERE-110. Extensive studies in several animal models,
including primates, have showed that NGF gene delivery to the basal
forebrain prevented the death of cholinergic neurons (which undergo
severe degeneration and death in Alzheimer's disease patients).
http://www.eurekalert.org/pub_releases/2004-09/rpsl-seg092004.htm
Testosterone loss may lead to Alzheimer's
A new study suggests that, like estrogen loss in older women, decreased
levels of testosterone may put aging men at risk for Alzheimer's
disease. The research suggests that testosterone both protects neurons
from injury, and reduces levels of beta-amyloid.
The findings were reported in a letter to the editor in the September 22
issue of the Journal of American Medical
Association.
Full reference
http://www.eurekalert.org/pub_releases/2004-09/uosc-alm092104.htm
August
Draining toxins from cerebrospinal fluid stabilizes cognitive decline
The ever-slowing capacity to clear the build-up of such toxins as
isoprostanes and misfolded proteins that accumulate in the brains of
Alzheimer's disease patients causes the death of cells involved in
memory and language. A preliminary study has shown that reducing the
levels of isoprostanes by draining cerebral spinal fluid can stave off
future reductions in cognitive abilities. Cognitive scores in the 8
patients receiving the treatment were stable after one year, while
scores in those not receiving the treatment declined 20%. The next phase
of the study involves nearly 100 patients.
The study appeared in the August issue of the
Journal of Alzheimer's Disease.
Full reference
http://www.eurekalert.org/pub_releases/2004-08/uopm-dti082004.htm
Early clinical treatment can halt progression of Alzheimer's disease
A study using genetically engineered mice has provided evidence that
early clinical treatment of brain lesions (by injecting
anti-beta-amyloid antibodies into the hippocampus) can halt the
progression of Alzheimer's disease. The clearance of amyloid plaques led
to the clearance of the lesions caused by neurofibrillary tangles. The
effect on neurofibrillary tangles only occurs, however, if done at a
particular stage of the tangle’s growth — the earlier the treatment
begins, therefore, the better the chance of success. The demonstration
that early treatment of amyloid plaques stops the progression of
Alzheimer’s provides support for the controversial theory that the
accumulation of amyloid plaques is the initiating trigger of the disease
process.
The findings are reported in the August 5 issue of
Neuron.
Full reference
http://www.eurekalert.org/pub_releases/2004-08/uoc--ect072804.htm
More support for role of mental stimulation in protecting against Alzheimer's
A study of 122 people with Alzheimer's and 235 people without the
disease found that people with Alzheimer's are more likely to have had
less mentally stimulating careers than their peers who do not have
Alzheimer's. Jobs were classified as mentally stimulating based on
complexity, variety of tasks, whether it involved creative thinking or
manipulation of data. Less mentally demanding jobs included more routine
and monotonous tasks. The association did not apply to occupations
during a person’s 20s. The study did not control for socioeconomic
status, and environmental demands and exposures of occupations, but did
control for educational levels.
The study is published in the August 10th issue of
Neurology.
http://www.eurekalert.org/pub_releases/2004-08/uhoc-tmj080904.htm
http://www.nature.com/news/2004/040809/full/040809-3.html
July
Studies suggest people with early AD can still learn
A new study suggests that people who have early stage Alzheimer's
disease could be more capable of learning than previously thought. The
study found that mildly impaired Alzheimer’s patients who participated
in 3-to-4 months of cognitive rehabilitation had a 170% improvement, on
average, in their ability to recall faces and names and a 71%
improvement in their ability to provide proper change for a purchase.
The participants also could respond to and process information more
rapidly and were better oriented to time and place. These improvements
were still evident 3 months after the cognitive training ended.
The findings are reported in the July-August 2004 issue of the
American Journal of Geriatric Psychiatry.
http://www.eurekalert.org/pub_releases/2004-07/nioa-ssp062904.htm
Alzheimer's may leave some forms of memory intact
A new study has demonstrated that people with Alzheimer's disease
retain the capability for a specific form of memory used for rote
learning of skills, despite their other memory loss. The finding
suggests new strategies to improve training and rehabilitative programs
for Alzheimer's sufferers. It also confirms other studies suggesting
that a number of brain systems are more intact in Alzheimer's than
previously thought.
The report was published in the June 10 issue of
Neuron.
Full
reference
http://www.eurekalert.org/pub_releases/2004-06/hhmi-als060404.htm
http://www.eurekalert.org/pub_releases/2004-06/cp-ssh060304.htm
Dementia often undiagnosed
A study involving 553 patients of 34 primary care physicians affiliated
with three Portland-area managed health care plans has confirmed
previous research finding that many older patients showing signs of
dementia are not being diagnosed. The study found that only 18% of
mildly impaired patients and 34.8% of moderately-to-severely impaired
patients were clinically evaluated for dementia, and that none of the
mildly impaired patients and just 4.3% of the more severely impaired
patients were offered dementia medication.
The study was published in the June issue of the
Journal of Gerontology: Medical Sciences.
http://www.eurekalert.org/pub_releases/2004-07/ohs-sdo071504.htm
Coronary artery bypass surgery not a risk factor for dementia
A comparison of dementia patients with controls has found that dementia
patients are no more likely than those without dementia to have had
coronary artery bypass surgery.
http://www.eurekalert.org/pub_releases/2004-07/mc-cab071504.htm
Some of the research reported at The 9th International Conference on Alzheimer's Disease and Related Disorders (ICAD), July 17-22, at the Pennsylvania Convention Center in Philadelphia, Pennsylvania:
Alzheimer's, cardiovascular disease share risk factors
A study of 4,081 women aged 65 years and older has investigated the relationship between cardiovascular risk factors and cognitive function. The researchers found a consistent increase in cognitive health paralleling higher levels of HDL (“good” cholesterol). A less robust correlation was seen for lower levels of LDL (or "bad") cholesterol and better cognitive performance. Triglyceride levels did not appear to influence cognition.
A study of over 700 elderly men and women has investigated the relationship between diabetes and cardiovascular disease risk factors and cognitive health. Researchers found that the presence of coronary heart disease, high cholesterol, or hypertension increased the risk of later cognitive decline, with a particularly strong effect in African Americans. They also found that although the diagnosis of diabetes increased the risk of cognitive decline by as much as two fold, the presence of high levels of fasting glucose (therefore, low insulin levels) substantially decreased the risk of cognitive decline in diabetic patients.
Data from a 24-week pilot trial of the diabetes drug rosiglitazone in patients with mild cognitive impairment (MCI) or very mild Alzheimer's disease found those who received rosiglitazone – a drug that boosts insulin activity – did not decline in their performance on memory and attention tests.
Data from an ongoing study of memory and aging among more than 3,300
residents age 65 and over from Cache County, Utah, has found that those
who had used anti-hypertension medications had a lower risk of getting
Alzheimer's. This benefit seemed most closely related to the use of
diuretics. Among this group of drugs, "potassium-sparing" diuretics were
associated with the greatest reduction in Alzheimer risk. The use of
other hypertension drugs, such as ACE (angiotensin converting enzyme)
inhibitors, calcium channel blockers, and beta-blockers, did not affect
Alzheimer risk.
References
http://www.eurekalert.org/pub_releases/2004-07/aa-acd070804.htm
Donepezil may have short-term benefit for mild cognitive impairment
Preliminary data from a recently completed clinical trial of 769
patients with mild cognitive impairment indicates that those taking the
drug donepezil were at reduced risk of progressing to Alzheimer's
disease for 18 months. The reduced risk disappeared after 18 months, and
by the end of the 3-year study, the probability of progressing to
Alzheimer’s was the same in the two groups. The study compared
donepezil, vitamin E, or placebo. There was no apparent benefit from
vitamin E.
http://www.eurekalert.org/pub_releases/2004-07/nioa-dmh071504.htm
http://www.eurekalert.org/pub_releases/2004-07/mc-tcs071504.htm
No clear-cut answers on statins as therapy for Alzheimer's disease
A study with genetically engineered mice found that those treated with simvastatin regained their ability to navigate mazes and that the drug improved performance even for the non-engineered mice in the control group.
Another study found that four different statins reduced, to varying extent, brain cells' production of a protein fragment thought to play a key role in Alzheimer's, with fluvastatin (Lescol, Novartis) being the most effective.
However, a review of all existing randomized controlled trials of statins in people without dementia (comprising over 30,000 participants) found no evidence yet that any statin protects against cognitive decline. In a second, small study of elderly people at risk for dementia, rates of brain tissue shrinkage, measured using a special MRI scan, were no different between statin users and nonusers.
New results from three, long-running population studies that assess the
possible impact of statins on preventing Alzheimer's suggest that the
benefit of statins in warding off dementia largely disappears if
patients are followed for several years. There are a number of
large-scale clinical trials underway to try and resolve this issue.
References
http://www.eurekalert.org/pub_releases/2004-07/aa-nca070804.htm
Minorities hardest hit by Alzheimer's disease
A study of 119 Latinos and 55 non-Latino white Alzheimer patients suggests that Latinos in the U.S. develop Alzheimer's symptoms much earlier than their white, non-Latino peers. There are several known factors which may be responsible for this apparent vulnerability in Latinos: high rates of vascular disease, leave school earlier, and less likely to use medical services or have health insurance than other Americans.
South Carolina, as the only U.S. state that keeps a comprehensive database of people with a diagnosis of Alzheimer's disease, has found that African Americans aged 55 to 64 years were more than three times as likely to have Alzheimer's as their European American counterparts. At ages 65 to 84, African Americans were more than twice as likely to have Alzheimer's. South Carolina has greater rates of obesity, diabetes, and related health problems than the rest of the country, especially amongst African Americans.
Another study has found that, in order to avoid overestimating the
number of African Americans who may have early signs of Alzheimer's
disease, screening tests must be adapted to cultural differences. The
study involved 635 people over the age of 60. Researchers found that,
using current scoring methods, African Americans scored lower on various
neuropsychological tests. Even when education was taken into account,
35% of African Americans scored low enough to warrant a diagnosis of
MCI, compared to only 15% of European Americans. However, when the
researchers applied new, racially sensitive scoring methods they've
developed, the difference in MCI rates disappeared.
References
http://www.eurekalert.org/pub_releases/2004-07/aa-mhh070704.htm
Alzheimer's Association offers information about providing culturally sensitive care at http://www.alz.org//Resources/Diversity/
