Archive for July, 2011

Scientists are looking at a biomaker that may possibly aid in the identification of individuals with mild memory problems who will eventually develop Alzheimer’s disease. The finding, which was published in the online version of Neurology, the journal of the American Academy of Neurology. It is believed that the new biomarker may prove to be more accurate compared to already established biomarkers.

According to the study author Robert Perneczky, MD, of the Technical University Munich in Germany, identifying individuals who will have Alzheimer’s disease earlier will be an important development. Once treatments that can be used for the prevention of the disease are available, it will become easier to treat and even prevent memory loss.

Fifty eight people with mild cognitive impairment (MCI) participated in the study. It is estimated that as many as 15% of the people who have MCI will develop Alzheimer’s every year.

Cerebrospinal fluid was taken from each participant and tested for certain proteins. Participants were then studied for about three years. Of the participants, 21 developed Alzheimer’s, 27 remained with MCI while 8 people regained normal cognitive skills. Researchers discovered that participants who later developed Alzheimer’s had significantly high levels of sAPPβ or soluble amyloid precursor protein beta in their cerebrospinal fluid.

Based on their findings, the researchers discovered that the person’s age, a protein called tau, and sAPPβ were excellent predictors of future cases of Alzheimer’s. Using these factors as a basis, it was easier to predict if an individual ran the risk of developing the disease. The accuracy for this prediction is pegged at about 80%.

A protein amyloid known as Aβ1-42 or amyloid beta1-42 was once considered one of the biomarkers significant to Alzheimer’s disease. However, it was not used as one of the predictive factors in the study.

The results, Perneczky said, suggest that sAPPβ could be useful as a biomarker and that it may even be better than Aβ1-42 for use in diagnosing Alzheimer’s earlier. The reason for this may be that Aβ1-42 can only indicate events at a later stage – events that already point to the accumulation of amyloid plaques in the brain. Since sAPPβ can be used as a critical initial step in determining if the disease will develop, it is likely to provide a more accurate indication on important pathological events.

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Possible New Drug for Alzheimer’s Disease

Taken orally, E64d, a type of cysteine pro-tease inhibitor, has shown to reduce the buildup of β-amyloid (Aβ) present in animal model brains used in Alzheimer’s disease studies. This action resulted in significant improvement in memory loss. The findings were discovered by a group of researchers from the American Life Science Pharmaceuticals-San Diego, University of California-San Diego and the Medical University of South Carolina. Their findings will be published in the Journal of Alzheimer’s Disease in the September issue.

Dr. Vivian Y.H. Hook praises the discovery since according to her, E64d has been proven safe for human consumption and that the results of the research has excellent potential for use in the treatment of Alzheimer’s disease.

It is known that there is a co-relation in the increase in the levels of Aβ peptides, amyloid plaques and the onset of loss of memory. Aβ peptides are separated from the APP or amyloid precursor protein by the β-secretase. The peptides later develop plaques in the regions of the brain associated with memory.

E64d reduces the level of Aβ by blocking the β-secretase from taking apart the amyloid precursor chain. However, researchers also discovered that it also increases BACE1 activity, a protease known as the principal β-secretase. E64d seems to decrease Aβ in the lower brain by blocking the β-secretase activities of Cathepsin B, another protease.

According to Hook, the study shows that Cathepsin B may be used for the inhibition of the production of Aβ and the resulting improvement of memory function. The finding is important since inhibition of β-secretase and Cathepsin-B is possible without the inhibition of BACE1.

The research involved the use of young and old mice with transgenic Alzheimer’s. Young mice fed with E64d avoided memory loss while old mice showed improved memory.

The study is not new — it actually used a previous work where Cathepsin B was also utilized for memory enhancement. In that study published in 2008, though, Cathepsin B inhibitors were directly administered into brains of mice with AD. The recent study shows that oral administration was effective and could pave the way for future human clinical trials.

The study is co-authored by Dr. Gregory Hook of San Diego’s American Life Science Pharmaceuticals and Dr. Mark Kindy of the Medical University of South Carolina, the Ralph H. Johnson VA Medical Center, and Applied Neurotechnology, Inc. in Charleston, SD. The recent study also received some support from the National Institutes of Health and the Alzheimer’s Drug Development Foundation’s National Institute on Aging.

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