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【medical-news】Alzheimer基因无症状携带者在出现该
http://www.medicalnewstoday.com/articles/116529.php
Brain scans of healthy middle aged carriers of the APOE-4 gene that is known to be a risk factor for Alzheimer's Disease, showed they had brain differences that were detectable long before symptoms of the disease were likely to appear.
Dr Shi Jiang Li, professor of biophysics at the Medical College of Wisconsin in Milwaukee, US, presented the results of the study today, July 29th, at the Alzheimer's Association International Conference on Alzheimer's disease in Chicago.
Li and colleagues conducted the study at Froedtert Hospital, a teaching hospital in southeast Milwaukee, where they recruited 28 neurologically-normal people aged from 45 to 65. Twelve of them were carriers of the APOE-4 gene, while the other 16 were not. There were no significant differences in age, educational level or neuropsychological performance between the two groups.
Using functional MRI (fMRI) brain imaging, the researchers found that the APOE-4 gene carriers had significantly fewer functional connections between two important memory processing centres of the brain: the hippocampus and the posterior cingulated cortex. These parts of the brain are used in acquiring, filtering and sorting information.
Compared to the gene carriers, the non-carriers had 65 per cent more functional connectivity between the two memory processing centres.
Li said that:
"Just as if cancer could be detected when there were only a few cells, decades before it was evident, the advantage of identifying those at great risk for having Alzheimer's would be of tremendous value in development of interventional therapies."
According to the Wellcome Trust, about 15 per cent of people carry the APOE-4 gene, which causes their bodies to produce a lipoprotein called apolipoprotein (Apo) E4. Lipoproteins carry lipids (fats) in the bloodstream and are made from a combination of fat and protein.
People who have only one APOE-4 gene from one parent are three times more likely than average to develop Alzheimer's Disease. People who inherit one gene from each biological parent are ten times more likely to develop the disease.
Scientists at the Oklahoma Medical Research Foundation published a study in The Journal of Neuroscience in April last year about how they discovered the molecular mechanism that links the gene to onset of Alzheimer's. They found that ApoE4 and other apolipoproteins attach themselves to receptors on the surface of brain cells, and this allows them to piggy back onto amyloid precursor protein which then enters the cell carrying its extra burden.
Once the mass of protein is inside the cell, proteases, special enzymes that cut up proteins, attack the amyloid precursor protein mass, resulting in a mass of protein fragments that scientists believe cause cell death, memory loss, and neurological dysfunction, all symptoms that are characteristic of Alzheimer's.
What is not clear from Li's study, is whether they have found a new effect from the APOE-4 gene, or whether they have found an early pre-onset symptom of the molecular mechanism discovered by the team at the Oklahoma Medical Research Foundation. 本人已认领该文编译，48小时后若未提交译文，请其他战友自由认领。 Brain scans of healthy middle aged carriers of the APOE-4 gene that is known to be a risk factor for Alzheimer's Disease, showed they had brain differences that were detectable long before symptoms of the disease were likely to appear.
对中年APOE-4基因（被认为是AD发病的危险因素）健康携带者的脑扫描发现，在AD症状之前，这些人的大脑已出现不同于正常人的改变。
Dr Shi Jiang Li, professor of biophysics at the Medical College of Wisconsin in Milwaukee, US, presented the results of the study today, July 29th, at the Alzheimer's Association International Conference on Alzheimer's disease in Chicago.
今天（7月28日）前来参加在Chicago举行的AD国际学术会议，来自美国Milwaukee市 Wisconsin 医学院的生物物理学教授，Shi Jiang Li博士报告了该项研究结果。
Li and colleagues conducted the study at Froedtert Hospital, a teaching hospital in southeast Milwaukee, where they recruited 28 neurologically-normal people aged from 45 to 65. Twelve of them were carriers of the APOE-4 gene, while the other 16 were not. There were no significant differences in age, educational level or neuropsychological performance between the two groups.
Li及其同事们是在Froedtert Hospital（位于Milwaukee东南部的一座教学医院）进行这项研究的，他们对神经病学表现正常，年龄为45-65岁的28人（其中有12人携带有APOE-4，另外16位为正常对照，两组人群的年龄、教育水平和神经心理学表现均无显著差异）进行了研究。
Using functional MRI (fMRI) brain imaging, the researchers found that the APOE-4 gene carriers had significantly fewer functional connections between two important memory processing centres of the brain: the hippocampus and the posterior cingulated cortex. These parts of the brain are used in acquiring, filtering and sorting information.
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作者:admin@医学,生命科学 2011-04-29 17:14
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