科學(xué)家認(rèn)為罹患阿茲海默癥的原因,，是由于患者腦中沈積著淀粉樣蛋白，日本國(guó)立長(zhǎng)壽醫(yī)學(xué)中心研究所的專家,，目前正在研發(fā)可以去除這種淀粉樣蛋白的疫苗,，疫苗在施用于實(shí)驗(yàn)小鼠身上后，發(fā)現(xiàn)具有恢復(fù)智慧的功效,。
這種新研發(fā)的疫苗,，是在不具病原性的病毒殼內(nèi)注入可制造淀粉樣蛋白質(zhì)的基因，以口服方式攝取的話,，可出現(xiàn)「?jìng)尾《尽沟姆磻?yīng),，淋巴球能制造出攻擊淀粉樣蛋白質(zhì)的抗體,，此抗體附著在沈積在腦中的淀粉樣蛋白上面,，并將此蛋白剝除。
研究小組利用基因技術(shù),，讓28只實(shí)驗(yàn)小鼠罹患阿茲海默癥,，在發(fā)病的情況下,，讓其中的14只服用疫苗，其余不服用,。
結(jié)果,，服用疫苗的小鼠在三個(gè)月后，幾乎都能通過(guò)記憶力,、學(xué)習(xí)能力等四種智力測(cè)驗(yàn),，恢復(fù)到等同于阿茲海默病發(fā)病前的程度。另一方面,，未服用疫苗的小鼠之認(rèn)知能力喪失了一大半,。這次研發(fā)的疫苗并非利用直接注射蛋白質(zhì)等的方式，所以安全性高,、可量產(chǎn),，只要飲用藥液即可，比較簡(jiǎn)單,。
科學(xué)家表示,，如果整個(gè)疫苗的研發(fā)作業(yè)完成后，就可以解決目前歐美正在研發(fā)的疫苗所遭遇的難題,，也就是安全性及成本等問(wèn)題,。日本的研究人員希望可以很快地進(jìn)行下個(gè)階段的研究，針對(duì)少數(shù)的阿茲海默患者進(jìn)行臨床實(shí)驗(yàn),。
(資料來(lái)源 : Reuters)
英文原文：
Alzheimer's vaccine works on mice: Japan scientist
Thu Mar 29, 2007 2:04PM EDT
By Isabel Reynolds
TOKYO (Reuters) - Japanese scientists have developed an oral vaccine for Alzheimer's disease that has proven effective and safe in mice, the director of a research institute behind the project said on Thursday.
The team is preparing to move to small-scale clinical trials in humans, possibly this year, said Takeshi Tabira, director of the National Institute for Longevity Sciences in Aichi, central Japan.
"We hope the Phase I trials go well," Tabira said. "Animals are able to recover their functions after developing symptoms, but humans are less able to do so. It may be that this only works in the early stages of the disease, when symptoms are light."
When administered to mice suffering from the disease, which causes dementia and is currently incurable, the vaccine reduced the amount of amyloid plaques in the brain and improved mental function.
Amyloid plaques are believed to be at the root of Alzheimer's -- a growing problem for aging populations around the world. The disease affects five million in the United States alone, the Alzheimer's Association said in a report last week.
The treatment did not cause inflammation or bleeding in the brains of the mice, Tabira said.
The vaccine is made by inserting amyloid-producing genes into a non-harmful virus. When taken orally, the virus stimulates the immune system to attack and break down the amyloid proteins in the brain, Tabira said.
The treatment was tested on 28 mice genetically modified to develop Alzheimer's disease. Half the animals were given a dose of the vaccine at the age of 10 months, while the control group were not treated.
Three months later, tests showed mental function in the treated mice had returned to levels close to those before they developed Alzheimer's symptoms.
U.S. drugmaker Wyeth and its Irish partner Elan Corp have an Alzheimer's vaccine called ACC-001 in early stage human trials.
The Japanese research, carried out in conjunction with scientists at Nagoya University and others, is to be published by the Federation of American Societies for Experimental Biology in July.
