没有单一原因或单因素本身足以导致广告;多种因素被认为函数序列或组合引起疾病。广告是一个复杂的过程,牵涉到很多因素影响大脑在很长一段时间。目前,亨德里(2001)文件,到目前为止两个风险因素与疾病的另外几人正在接受调查。已知的危险因素是年龄和家庭历史/遗传性格。广告的风险指数随着年龄的增加,65年后每十年翻一番(威尔逊和班尼特,2003)。个人从家庭历史的广告更患该疾病的风险。到目前为止,研究人员指出了三个基因负责疾病的基因联系(鸟和Tsuang白克力,Yu,2010)。其他潜在的风险因素包括性别和教育水平。女性更容易受到疾病,但其发生率可能是因为年龄的影响,众所周知,女性平均寿命比男性(亨德里,2001)。与教育水平,威尔逊和班尼特(2003)的研究提到,个人多年的正规教育有一个低风险的发展广告相比,老年教育水平较低的个体。
环境问题和代谢障碍也与广告的发展。研究最多的环境犯罪嫌疑人与锌和铝金属中毒,病毒感染和食源性毒药。铝成为嫌疑人广告后解剖研究表明微量的金属人屈服于广告(亨德里,2001)。尽管许多研究以来一直未能证实这一发现毫无疑问或有可疑的结果,很明显,发生在铝浓度高于通常在几个尸检发现阿尔茨海默氏症患者。威尔逊和班尼特(2003)建议的风险更高的广告个体使用止汗剂和抗酸剂浓度高的铝。锌被牵涉进广告在两个方面。一些研究人员假设缺锌可能是负责任的而另一些人则认为,高锌水平可能是问题(亨德里,2001)。缺锌隐含了后期研究发现低水平的锌的大脑(尤其是海马)患者死于广告。相比之下,另一个研究提到,过量的锌水平可能负责(亨德里,2001)。在这个研究中,锌了沉淀可溶性β淀粉样斑块的脑脊液变成一团像在AD患者的大脑(亨德里,2001)。食源性毒物如毒素已经与某些类型的痴呆。一些豆类种子被证实含有氨基酸,当摄入可能会导致神经损伤。这两个法案通过提高神经递质谷氨酸的活动,还涉及广告。在加拿大,一个神经系统疾病类似于广告的流行发生在人吃了污染的肌肉Demoic酸,谷氨酸刺激器(威尔逊和班尼特,2003)。病毒一直在暗示广告,因为在过去,病毒已被证明导致某些神经系统疾病年后进入身体。这么多年来,Goedert和Spillantini(2006)文档,研究人员在广告寻求病毒或其他传染性病原体。
Law Assignment代写 单一原因
There is no single known cause or a single factor sufficient by itself to lead to AD; multiple factors are thought to function in sequence or combination to cause the disease. AD is a complex process, involving many factors that affect the brain over a long time. Currently, Hendrie (2001) documents that so far two risk factors are linked to the disease while several others are under investigation. Known risk factors are age and family history/genetic disposition. The risk of AD increases exponentially with age, doubling in each decade after 65 (Wilson and Bennett, 2003). Individuals from families with a history of AD have a more risk of developing the disease. To date, researchers have pointed out the three genes responsible for the genetic link of the disease (Bekris, Yu, Bird and Tsuang, 2010). Other potential risk factors include gender and educational level. Females are more susceptible to the disease, but their incidences could be because of the effects of age - on average female gender is known to live longer than male gender (Hendrie, 2001). In relation to educational level, a research by Wilson and Bennett (2003) alludes, individuals who have more years of formal education have a lower risk of developing AD in old age compared to individuals with lower educational levels.
Environmental aspects and metabolism disorders have also been linked to development of AD. The most studied environmental suspects are metal poisoning with zinc and aluminum, viral infections and foodborne poisons. Aluminum became a suspect in AD after autopsy studies demonstrated trace amounts of the metal in individuals who had succumbed to AD (Hendrie, 2001). Although many studies since have not been able to confirm this finding beyond doubt or have had questionable results, it is evident that aluminum occurs in higher concentrations than usual in several autopsy findings of Alzheimer's patients. Wilson and Bennett (2003) suggest a higher risk of AD among individuals used antiperspirants and antacids with high concentrations of aluminum. Zinc has been implicated in AD in two ways. Some researchers hypothesize low zinc levels could be responsible while others argue that high zinc levels could be the problem (Hendrie, 2001). Low zinc levels were implied by postmortem studies that found low levels of zinc in the brains (especially the hippocampus) of patients who had succumbed to AD. In contrast, another research alludes that excess zinc levels may be responsible (Hendrie, 2001). In this research, zinc was demonstrated to precipitate soluble beta amyloids in the cerebrospinal fluid into clumps like the plaques demonstrated in the brains of AD patients (Hendrie, 2001). Foodborne poisons such as toxins have been associated with some types of dementia. Some legume seeds have been confirmed contain amino acids that may cause neurological damage when ingested. Both act by enhancing the activity of the neurotransmitter glutamate, also implicated in AD. In Canada, an epidemic of a neurological disease analogous to AD occurred among people who had eaten muscles contaminated with Demoic acid, a glutamate stimulator (Wilson and Bennett, 2003). Viruses have been suggested in AD because, in the past, viruses have been demonstrated to lead to some neurological diseases years after entering the body. So for years, Goedert and Spillantini (2006) document that researchers have sought viruses or other infectious agents in AD.
