甘露醇可用于治疗帕金森症

海量资料下载 免费学习英语 www.englishvip.com/xinlw.htm （申请网址） Mannitol（甘露醇）, a sugar alcohol produced by fungi, bacteria, and algae, is a common component of sugar-free gum and candy. The sweetener is also used in the medical field -- it's approved by the FDA as a diuretic（利尿剂） to flush out excess fluids and used during surgery as a substance that opens the blood/brain barrier to ease the passage of other drugs. Now Profs. Ehud Gazit and Daniel Segal of Tel Aviv University's Department of Molecular Microbiology and Biotechnology and the Sagol School of Neuroscience, along with their colleague Dr. Ronit Shaltiel-Karyo and PhD candidate Moran Frenkel-Pinter, have found that mannitol also prevents clumps of the protein α-synuclein from forming in the brain -- a process that is characteristic of Parkinson's disease.   These results, published in the Journal of Biological Chemistry and presented at the Drosophila Conference in Washington, DC in April, suggest that this artificial sweetener could be a novel therapy for the treatment of Parkinson's and other neurodegenerative diseases. The research was funded by a grant from the Parkinson's Disease Foundation and supported in part by the Lord Alliance Family Trust.   Seeing a significant difference   After identifying the structural characteristics that facilitate the development of clumps of α-synuclein, the researchers began to hunt for a compound that could inhibit the proteins' ability to bind together. In the lab, they found that mannitol was among the most effective agents in preventing aggregation of the protein in test tubes. The benefit of this substance is that it is already approved for use in a variety of clinical interventions, Prof. Segal says.   Next, to test the capabilities of mannitol in the living brain, the researchers turned to transgenic fruit flies engineered to carry the human gene for α-synuclein. To study fly movement, they used a test called the "climbing assay," in which the ability of flies to climb the walls of a test tube indicates their locomotive capability. In the initial experimental period, 72 percent of normal flies were able to climb up the test tube, compared to only 38 percent of the genetically-altered flies.   The researchers then added mannitol to the food of the genetically-altered flies for a period of 27 days and repeated the experiment. This time, 70 percent of the mutated flies could climb up the test tube. In addition, the researchers observed a 70 percent reduction in aggregates of α-synuclein in mutated flies that had been fed mannitol, compared to those that had not.   These findings were confirmed by a second study which measured the impact of mannitol on mice engineered to produce human α-synuclein, developed by Dr. Eliezer Masliah of the University of San Diego. After four months, the researchers found that the mice injected with mannitol also showed a dramatic reduction of α-synuclein in the brain.   Delivering therapeutic compounds to the brain   The researchers now plan to re-examine the structure of the mannitol compound and introduce modifications to optimize its effectiveness. Further experiments on animal models, including behavioral testing, whose disease development mimics more closely the development of Parkinson's in humans is needed, Prof. Segal says.   For the time being, mannitol may be used in combination with other medications that have been developed to treat Parkinson's but which have proven ineffective in breaking through the blood/brain barrier, says Prof. Segal. These medications may be able to "piggy-back" on mannitol's ability to open this barrier into the brain.   Although the results look promising, it is still not advisable for Parkinson's patients to begin ingesting mannitol in large quantities, Prof. Segal cautions. More testing must be done to determine dosages that would be both effective and safe 甘露糖醇（甘露醇）的糖醇生产的真菌，细菌，藻类，是无糖口香糖和糖果的共同组成部分。的甜味剂，也可用于在医疗领域的-它被FDA批准作为利尿剂（利尿剂）排出多余的流体，并在手术过程中使用的物质，打开缓解其他药物通过血/脑屏障。现在两位教授。特拉维夫大学分子微生物学与生物技术系和Sagol神经科学学院，以及他们的同事博士Ronit Shaltiel卡尤博士生莫兰法兰克·品特，埃胡德·加齐特和丹尼尔·西格尔发现，甘露醇还可以防止的蛋白质团块在大脑中形成的α-共核蛋白-一个过程，是帕金森氏病的特征。   这些研究结果发表在生物化学杂志，发表于4月在华盛顿特区，在果蝇的会议，建议，这种人工甜味剂可能是用于治疗帕金森氏症和其他神经退行性疾病的一种新型疗法。资助这项研究是由帕金森氏症基金会的资助和支持部分由主联盟的家族信托。   看到一个显着差异   识别的结构特点，促进发展的α-突触核蛋白的团块后，研究人员开始寻找一种化合物，能够抑制蛋白质的能力结合在一起。在实验室中，他们发现，甘露糖醇的最有效的防止试管中的蛋白质聚集剂。这种物质的好处是，它已被批准用于在各种临床干预，，西格尔教授说。   接下来，为了测试的甘露醇​​在客厅大脑的能力，研究人员转向苍蝇工程进行人类基因α-synuclein的转基因水果。要研究飞运动，他们使用了所谓的“登山测定测试”，在这种能力的苍蝇爬壁试管中表示机车能力。在最初的实验期间，72％的正常果蝇能够爬上试管，而只有38％的基因改变的苍蝇。   然后，研究人员添加甘露醇食品的基因改变了一个为期27天的苍蝇，反复的实验。这一次，70％的变异苍蝇爬上试管。此外，研究人员观察到减少70％的α-突触核蛋白的聚集变异苍蝇一直喂甘露醇相比，那些有。   这些发现证实了第二项研究测量的影响甘露醇对小鼠设计生产人α-突触核蛋白开发的的埃利泽Masliah博士圣地亚哥大学。4个月后，研究人员发现，小鼠注射甘露醇α-突触核蛋白在大脑中也出现了大幅度的减少。   治疗化合物交付到大脑   研究人员现在打算重新审视甘露醇化合物的结构和引入的修改，优化其有效性。进一步的实验动物模型，包括行为测试，其疾病的发展更紧密的发展需要在人类帕金森氏模仿，，西格尔教授说。   西格尔教授说，当时，甘露醇可用于与其他药物的组合已被开发用于治疗帕金森氏症，但已经证明是无效的血/脑屏障突破。这些药物可能能够甘露醇的能力，打开这道屏障进入大脑的“背驮式”。   虽然结果看起来前途的，它仍然是不可取的帕金森氏症患者开始摄取大量的甘露醇，西格尔教授提醒。必须做更多的测试，以确定这将是既有效又安全的剂量。 “成千上万人疯狂下载。。。。。。 更多价值连城的绝密英语学习资料， 洛基内部秘密英语，技巧，策略 请在 网上 申请报名” 洛基国际英语 竭诚为您服务