我故我在
2009年3月25日星期三
常用网盘
千脑永久保存用户文件,永不删除,免费最大100G,不限文件大小,最适合文件分享和长期保存,而且他的特色是你将拥有一台在线的电脑!!(推荐!)
DropBox
严格意义来说,DropBox并不是一款用于与别人共享文件的网络硬盘,但它的同步功能是别的所有任何网盘都没有的,非常强大的哟!具体可以查看DropBox的图文介绍
Mediafire
无限容量 无限带宽 文件最大100M 文件后台管理 简单统计 免费 无须注册(Jimmy使用过最好的一个在线存储网站,可惜的是去年就不幸撞墙了。)
纳米盘
1G固定容量 文件最大4G 文件后台管理 纳米机器人工具 国内服务 无须注册
Rayfile
原先叫FS2You现在改名为Rayfile 无限容量 无最大上线 文件后台管理 客户端Rayfile 国内服务 其他都不错就是客户端总是开着一个进程让人不安。
UUshare
初始帐户512容量 良好的文件管理系统 不过对于单个文件限制过严 用户体验不错。
Skydrive
微软提供的服务,之前是5G空间后来涨到了25G。需要LIVE帐号。
Box
Box的在线文件存储服务一直都很多Geek所推崇,可惜的是免费帐号的空间太小只有1G,而且限制最大单个文件为25MB最多五个文件夹。
drop.io
一款非常有创意的在线存储分享的服务,无须注册 每次最大100MB Jimmy个人很喜欢它的界面风格。
Flyupload
支持最大2G的文件 无须注册 很简单的界面很实在的服务。
Easyshare
拥有四种上传方式,上传速度不错还可以赚钱。但下载比较复杂用户体验不佳。
QQ群邮件附件文件中转站
速度方面还不错但下载次数限制对于那些内容劲爆的东西而言很快就耗尽了。
以上就是Jimmy简单介绍的一些免费的在线网络硬盘和文件存储的服务,当然以上都是Jimmy自己常用的一些,如果大家有还有更好的请一定在评论中和大家一同share。一直寄希望于Google能出一个在线硬盘的服务但所谓的GDrive都没有出现。
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2009年3月4日星期三
stroke的血压管理
【2】急性期卒中患者血压调控
急性期卒中患者80%合并高血压,出血性卒中比缺血性卒中血压增高更明显,持续时间较长。关于卒中急性期的降血压治疗,AHA和美国卒中学会(ASA)在2007年联合发布的《成人缺血性卒中早期治疗指南》中指出:
①很多卒中患者在24小时内有血压自发性下降的趋势,在有确凿证据前应谨慎控制血压;对有其他适应证的高血压患者,应严格控制血压(对于高血压脑病、接受溶栓治疗、全身性疾病患者可以用降压药控制血压,降压的幅度应<20%);对血压急剧升高者应积极治疗,24小时内血压降15%;一般认为当收缩压>220mmHg或平均血压>120mmHg时,应给予降压治疗。
②临床研究显示,卒中发生后24小时内开始降压治疗相对安全,对于无禁忌证、既往患有高血压且神经系统症状稳定的患者可在卒中后24小时开始降压治疗。
③降压治疗中对药物的选择尚无相关证据。
关于急性脑梗死降压药物的选择,ACCESS研究观察在缺血性卒中的36~72小时内应用坎地沙坦降低血压对心脑血管事件的影响,发现坎地沙坦组的死亡及心血管事件的相关风险较安慰剂组降低47.5%,致死和非致死性卒中的危险性降低24%和28%。该研究证明,急性缺血性卒中早期采用ARB类降压药控制血压可获益。
另外,ACCOST研究在卒中后应用坎地沙坦控制血压的安全性,发现应用坎地沙坦12周后收缩压降低10mmHg,舒张压降低3.7mmHg,结果提示卒中后急性期(72小时)应用坎地沙坦控制血压是安全的,而且可以较快地达到目标血压。
【3】1周后做TCD和颈部血管彩超,了解双侧颈动脉狭窄程度,个体化控制血压,参考rose的帖子:
单侧颈动脉狭窄大于70%,收缩压控制在130-150mmHg之间;如果双侧颈动脉狭窄都大于70%,收缩压应该保持在150mmHg以上;如果是其他情况,血压低于140mmHg是安全的
2009年2月15日星期日
一种神经营养因子蛋白能够保护ad
At the University of California, San Diego, scientists identified brain-derived neurotrophic factor (BDNF), a protein produced in the entorhinal cortex of the brain, as a substance that has the potential to provide long-lasting protection against Alzheimer’s disease in animal models. Studies need to be done to determine the value of BDNF in humans at risk for or with the disease.
What is Brain-Derived Neurotrophic Factor?
Brain-derived neurotrophic factor is a protein manufactured in an area of the brain that supports memory. It’s been shown that BDNF production, which continues throughout a person’s lifetime, decreases in people who have Alzheimer’s disease. This new study, the results of which were published in the February 8, 2009 issue of Nature Medicine, showed BDNF to have a very powerful impact on brain cells.
Study Results
The researchers injected the BDNF protein into various cell cultures and animal models, including rats and monkeys who had damage to their entorhinal cortex. When compared with control animals, who were not treated with BDNF, the treated animals did significantly better on memory and learning tests.
When the brains of the treated animals were examined, they had enhanced cell size, improved signaling between cells, and activity in neurons that would have degenerated due to Alzheimer’s disease if BDNF had not been administered. The scientists also saw improvement in the hippocampus, which is one of the first areas of the brain that is damaged in Alzheimer’s disease, and also where short-term memory is processed.
According to the study’s experts, BDNF directly affects the dying cells in specific memory areas of the brain. The protein prevents cell death, stimulates cell function, and thus improves memory and learning. For these reasons, the researchers are hopeful that BDNF treatment will someday provide lasting protection against Alzheimer’s disease.
Possible New Treatment Approach
Most of the current experimental treatments for Alzheimer’s disease focus on preventing or stopping the accumulation of amyloid plaque, protein fragments that build up between the nerve cells in the brain of people with Alzheimer’s disease. Treatment with BDNF would offer an alternative treatment approach, because it targets a different disease mechanism than plaque development. Therefore, there is a potential for clinicians to combine amyloid-based treatments with BDNF and thus expand the scope and hopefully the success of treatment for people who have this devastating disease.
2009年2月14日星期六
防治高血压的良好建议
(This column is authored by Carol Koenigsknecht, Herbal Practitioner and owner of Terra Ken Herbals. She is available for consultations, classes and lectures, and can be reached via her website athttp://www.TerraKenHerbals.net or by phone, (706) 797-0091. She also owns and operates Carol’s Critter Care, a pet-sitting service.)
腹型肥胖增加妇女偏头痛的风险
Belly Fat Linked to Risk of Migraines
WebMD Health News
Feb. 13, 2009 -- Belly fat has been linked to increased risks for heart disease and diabetes. Now new research suggests it may also be linked to an increased risk for migraines, at least until middle age.
Waist circumference was found to be a better predictor of migraine activity than general obesity in both men and women up until age 55.
Earlier research has linked obesity with an increase in the frequency of migraines in people who already have them. But the new study is one of the few to suggest that obesity raises the overall risk for migraines.
And it is the first to examine whether belly fat may play a specific role in migraines and severe frequent headaches.
The findings will be presented in April at the annual meeting of the American Academy of Neurology (AAN) in Seattle.
Belly Fat and Migraines
Researchers from Philadelphia's Drexel University College of Medicine examined data collected from more than 22,000 participants in the ongoing National Health and Nutrition Examination Survey (NHANES).
The survey included measurements of both abdominal obesity, measured by waist circumference, and overall obesity, as determined by body mass index (BMI). The data also include self-reported estimates of migraine and severe headache frequency.
Women are three times as likely as men to suffer from migraines. Researcher B. Lee Peterlin, DO, tells WebMD that the findings may help researchers understand this gender difference.
"This may be one piece of the puzzle," she says. "This does not suggest that if you lose your extra abdominal fat it will cure your migraines. But it may be a clue to help explain the sexual dimorphism in migraine."
Even after controlling for overall obesity, excess belly fat was associated with a significant increase in migraine activity in both men and women between the ages of 20 and 55.
"This is the age when migraine is most prevalent," she says. "Our findings suggest that both general obesity and abdominal obesity are associated with an increased prevalence of migraine in this age group."
Women with extra belly fat were 30% more likely to experience migraines than women without excess belly fat, even after accounting for overall obesity, risk factors for heart disease, and demographic characteristics. The link between belly fat and migraines in men in this age group was not significant when accounting for these factors.
Migraines in Women
The findings suggest that belly fat is an important risk factor for migraine, but it may be more important in women than in men, Peterlin says.
After age 55, carrying extra weight around the middle appeared to be associated with a slight decrease in migraine risk in women, but the reasons for this are not clear.
"That was a surprise," Peterlin says. "It appears that there is an impact at every age, but it changes. In women under 55, belly fat is bad. But over 55, having belly fat may actually be mildly protective against migraine."
Migraine researcher Stephen Silberstein, MD, tells WebMD that the new research raises more questions than it answers.
Silberstein is a spokesman for the American Academy of Neurology and a professor of neurology at Thomas Jefferson University in Philadelphia.
"The large population-based studies indicate that obesity correlates with the frequency, but not the presence of migraines," he says. "This is the first time anyone has looked at abdominal girth and they found that it predicts the presence of migraines. This is an interesting observation, but these findings would definitely need to be duplicated."
植物病毒提供智能炸弹炸死癌细胞
Washington, Feb 13 (ANI): In a major step towards better chemotherapy treatments, scientists have created tiny “smart bombs” by modifying a common plant virus, which can deliver drugs only to specific cells inside the human body without affecting surrounding tissue.
The researchers have revealed that each of these smart bombs is thousands of times smaller than the width of a human hair.
They say that the new approach may lead to more effective chemotherapy treatments with greatly reduced, or even eliminated, side effects.
In a collaborative effort, Drs. Stefan Franzen, professor of chemistry, and Steven Lommel, professor of plant pathology and genetics, used the special properties of a fairly common and non-toxic plant virus as a means to convey drugs to the target cells.
According to the researchers, the virus is appealing in both its ability to survive outside of a plant host and its built-in “cargo space” of 17 nano-meters, which can be used to carry chemotherapy drugs directly to tumour cells.
They deployed the virus by attaching small proteins, called signal peptides, to its exterior that cause the virus to “seek out” particular cells, such as cancer cells.
The same signal peptides serve as “passwords” that allow the virus to enter the cancer cell, where it releases its cargo.
“We had tried a number of different nanoparticles as cell-targeting vectorsThe plant virus is superior in terms of stability, ease of manufacture, ability to target cells and ability to carry therapeutic cargo,” said Franzen.
Calcium is the key to keeping the virus” cargo enclosed. When the virus is in the bloodstream, calcium is also abundant.
However, inside individual cells, calcium levels are much lower, which allows the virus to open, delivering the cancer drugs only to the targeted cells.
“Another factor that makes the virus unique is the toughness of its shell. When the virus is in a closed state, nothing will leak out of the interior, and when it does open, it opens slowly, which means that the virus has time to enter the cell nucleus before deploying its cargo, which increases the drug’’s efficacy,” said Lommel.
The researchers are hoping that their method will alleviate the side effects of common chemotherapy treatments, while maximizing the effectiveness of the treatment
2009年2月13日星期五
尿酸增加青年人的死亡风险
In middle-aged Chinese adults, high blood levels of uric acid are a strong predictor of death from cardiovascular disease, stroke and all causes, according to results of a study conducted in Taiwan.
This finding was true not only in high-risk groups but in the general population, and potentially in low-risk groups as well, Dr. Wen-Harn Pan of the National Taiwan University, Taipei, and associates report in the journal Arthritis & Rheumatism.
Uric acid is a product of the breakdown of nitrogen compounds, and is normally excreted in urine. It has been recognized for decades that uric acid is found at high levels in the joints of people with gout. More recently, it has been suggested that uric acid may be a "danger signal" released by damaged cells that triggers inflammation and a strong immune response.
Pan's team studied data on approximately 42,000 men and 49,000 women whose average age was 51 years. All of them had health exams between 1994 and 1996 and were followed until the end of 2003.
High uric acid -- defined as a blood level greater than 7 milligrams per deciliter -- was documented at the first exam in 40 percent of men and 11 percent of women. During an average follow-up of 8.2 years, 5,427 study subjects died and 1,151 of these deaths were attributed to cardiovascular disease.
In the overall study population, a high blood uric acid level was associated with a statistically significant increased risk of death from cardiovascular disease, stroke, congestive heart failure or any cause.
A high blood uric acid level had even greater impact on death among people with high blood pressure and diabetes.
According to Pan, a high blood uric acid level is a risk factor for cardiovascular-related death "even in those without traditional cardiovascular disease risk factors. It is important to examine whether uric acid is involved in the early stage of disease development."
Summing up, Pan said: "Our data showed that people with higher uric acid levels had poorer survival than those with lower levels. However, whether lowering it would translate into improved survival awaits further clinical trials."
SOURCE: Arthritis & Rheumatism, February 15, 2009.
2009年2月12日星期四
小脑出血
小脑出血患者中约有1/5病情呈迅速进行性加重,并可在48h内陷入昏迷而死亡;大多数患者病情较急,呈进行性加重;少数患者为慢性进行性,类似小脑占位病变。小脑出血时如出现小脑扁桃体疝、延髓衰竭,则预后不良。小脑出血如病情进展,早期出现脑干受压征象以及血肿大于3cm,必须及早进行手术。
总之,以下几点有助于小脑出血的临床诊断:①临床上以眩晕、头痛、呕吐为首发症状,随后迅速或逐渐出现意识障碍;②突然昏迷者如伴有脑干体征,特别是双侧脑干体征,如双侧瞳孔中度缩小、光反应不消失、眼球分离、凝视麻痹、双侧锥体束征以及脑神经损害;③出现小脑体征;④脑膜刺激征阳性,伴有强迫头位;⑤CT扫描能迅速做出诊断。有助于小脑出血的诊断。(1)老年人群、既往患有高血压等脑血管病危险因素。(2)多于活动状态下突然枕顶区疼痛、眩晕、频繁呕吐、垂直性眼震、小脑性共济运动失调,继而迅速或渐进出现意识障碍及呼吸衰竭。(3)突然单侧周围性面瘫、瞳孔缩小、外展神经麻痹。(4)四肢肌张力低、腱反射弱(排除安眠药中毒、电解质平衡失调)。(5)强迫体位(颈项前倾),5~8h后出现脑膜刺激征阳性(血液破入蛛网膜下腔)。但无偏瘫,病理征阴性。应高度疑视本病,尽快行脑CT检查,以明确或排除诊断。
小脑疾病的定位定性
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小脑实际上接受神经系统所有部分的信息,反过来再通过传出联系实施其影响。与大脑的联系间具有躯体定位顺序关系,对各类动物,包括灵长类诱发电位的研究说明了这点。因此认为人类的小脑皮质也遵从躯体定位的原则。
在动物实验中已发现,特定功能缺失与某一确定的小脑区域受损有关。而在小脑病变时,这些关连不常见,为了在运动或保持某种姿势时维持平衡和一定的肌张力并保证随意运动和非随意运动的圆滑协调和精确,小脑必须作为一个整体发挥作用。
以下因素使小脑疾病的定位诊断变为复杂:
1.损伤仅限于小脑某一特定功能区的情况较少见。
2.在良性肿瘤之类的慢性损伤,残存的小脑实质能代偿损伤区的功能,一段时间内可能很少出现或不出现临床症状。
3.虽然损伤深部小脑核团的功能代偿几乎不可能,但脑的其它部分仍能代偿缺失的小脑功能。
HSP遗传性痉挛性截瘫
【遗传形式】 国内外研究报道,HSP的遗传形式可呈常染色体显性遗传(AD)和常染色体隐性遗传(AR),少见X-连锁隐性遗传(XR),散发病例也不少见。国内学者总结国内文献报道的HSP (共117个家系,435例患者)的遗传特点,发现常染色体显性、常染色体隐性、X-连锁隐性遗传分别为41、13、2个家系,约占HSP的35.04%、11.11%、1.71%,与国外报道遗传形式基本一致。
【遗传学和发病机制】 HSP有明显的遗传异质性,目前分子遗传学研究发现,HSP的基因分型至少有16型,已有4型疾病基因被克隆。16型分别为:①X-连锁隐性遗传(XR)3型,分别是HSP -1,定位于Xq28,疾病基因已克隆,为神经细胞粘附分子L1基因,即LICAM基因;HSP -2定位于Xq22,疾病基因已克隆,为髓鞘蛋白脂蛋白基因,即PLP基因;HSP -16定位于Xqll。②常染色体显性遗传(AD)8型,分别是HSP -3A定位于14q11.2~q24.3;HSP -4定位于2p22~21,疾病基因为痉挛蛋白基因(Spastin基因);HSP -6定位于15q11.1;HSP -8定位于8q23~q24;HSP-9定位于10q23.3~q24.1;HSP-10定位于12q13;HSP-12定位于19q13;HSP-13定位于2q24;HSP-17定位于llql2。③常染色体隐性遗传(AR)5型,分别是HSP-5A定位于8q12~13;HSP-5B尚未定位;HSP-7定位于16q24.3,疾病基因为截瘫蛋白基因(Paraplegin基因);HSP-11定位于15q13~q15;HSP-14定位于3q27~q28;HSP-15定位于14q。
L1CAM基因编码的神经细胞粘附分子L1是粘附分子免疫球蛋白G超家族中的一员,主要在神经细胞中表达,与神经元一神经元粘附以及其他一些重要的神经元相互作用有关。Jouet等(1994),在 HSP-1研究中发现了LICAM基因突变与HSP-1发病相关,突变形式可表现为错义突变、无义突变及缺失突变。另外,LICAM基因突变还可引起X-连锁的MASA综合征(Mental Retardation,Aphasia Shuffling gait,Adducted Thumb Syndrome)、X-连锁的脑积水及X-连锁的胼胝体发育不全。因此,我们称这4种病为等位基因病(allelic diseases)。由于这4种病的临床特征显示有相当大的重叠,以胼胝体发育不全(corpus callosum hypoplasia)、精神发育迟滞(mental retardation)、拇指内收(Adducted thumbs)、遗传性痉挛性截瘫(hereditary spastic paraplegia)和脑积水(Hydrocephalus)为特征,最近将这些疾病概括在一起,命名为CRASH综合征。
髓鞘蛋白脂蛋白(PLP)基因编码两个主要髓鞘蛋白:PLP及其异构体DM20蛋白。PLP的mRNA特异性表达于中枢神经系统(CNS)组织,而DM20的mRNA可见于CNS、心脏及其他组织。PLP约占CNS髓鞘总蛋白含量的50%,其生物功能主要是在髓鞘形成及保持功能结构中发挥作用。Saugier-Veber等(1994)突变分析研究发现在HSP-2患者有PLP基因突变,确定PLP基因是HSP-2的疾病基因。有趣的是PLP基因突变还与佩-梅病(Pelizaeus-Merzbacher disease,PMD)发病有关。因此,HSP-2和PMD也为等位基因病。已发现PLP基因突变有30余种,点突变约占突变的15%~20%,常见于HSP-2;重复突变多见于PMD。
Hazan等(1999)研究发现Spastin基因突变引起HSP-4。Spastin是一种氨基酸ATP酶(Amino Acid ATPase,AAA)蛋白家族的一个成员。HSP-4广泛表达于人类成人及胎儿组织,定位于核中,与26S蛋白酶同源,可能与核蛋白生物功能和聚集有关。到目前为止,40%~50%HSP-4被发现有 spastin基因的突变,约有39种,包括11种错义突变、6种无义突变、10种剪接位点突变、8种小缺失突变、3种插入突变和1种大缺失突变等。
Ciorgio Lasari等(1998)在HSP-7病人中发现了Paraplegin基因的一种9.5kb缺失的杂合突变,另外他们还发现了两种移码突变,导致截短的Paraplegin蛋白的产生,确定paraplegin基因是HSP-7的疾病基因。Paraplegin是一种线粒体金属蛋白酶,与酵母线粒体ATP酶高度同源,转染的Cos-7细胞免疫荧光分析和体外线粒体表达实验表明,Paraplegin蛋白存在于线粒体内膜,它有线粒体膜内蛋白水解作用,分子伴侣(chaperone)样活性,线粒体蛋白翻译后的装配,多肽链的错误折叠或翻译等功能有关。在有Paraplegin突变的两个病人的肌活检分析中发现存在典型的线粒体氧化磷酸化缺陷,提示此缺陷可能是HSP-7型疾病神经变性的一种发病机制。
【病 理】 基本的病理形态改变主要是双侧皮质脊髓侧束的轴索变性和脱髓鞘,以胸段最重;皮质脊髓前束脱髓鞘往往不很严重;双侧脊髓小脑束和薄束也有脱髓鞘改变。此外,前角细胞、巨锥体细胞、基底节、脑干、小脑、视神经等也可有病理改变。Behan和Maia两次尸检研究后认为在脊髓中上行和下行长束远端的轴索变性是HSP的特征性表现,最近在有para ptegin基因突变的HSP病人的股四头肌肌肉活检时发现有破碎红纤维(RRF)及细胞色素C氧化酶(COX)阴性纤维,这显示有线粒体功能异常。至于线粒体异常仅仅与HSP-7有关还是在其他基因型 HSP中都存在仍不清楚。
【临床表现】 HSP的发病年龄多见于儿童期或青春期,但也可见于其他年龄段。男性略多于女性。常有阳性遗传家族史。临床表现为缓慢进展的双下肢痉挛性肌无力,肌张力增高,腱反射活跃亢进,膝、踝阵挛,病理征阳性,呈剪刀样步态等。可伴有视神经萎缩、视网膜色素变性、锥体外系症状、小脑性共济失调、感觉障碍、痴呆、精神发育迟滞、耳聋、肌萎缩、自主神经功能障碍等。还可有弓形足畸形。部分HSP家族有遗传早现(Anticipation)现象。
HSP分型:Harding(1984)的分型方法为大多数学者接受。Harding按临床表现分为两型:一为单纯型HSP,是临床最常见的HSP。主要表现为痉挛性截瘫,也有遗传异质性,呈常染色体显性遗传,或常染色体隐性遗传,病理改变主要在脊髓锥体束变性,而脊髓小脑束、后索改变不明显。显性遗传的HSP又按年龄分为早发型和晚发型。早发型最多见,常于35岁前发病,这型HSP患者行走较迟,双下肢僵硬,不灵活,痉挛性瘫痪,腱反射亢进、膝踝阵挛阳性,病理征阳性。双上肢可有轻微手指活动不灵活,腱反射活跃,深感觉障碍随病程进展而越来越明显。括约肌障碍和弓形足也可见。晚发型患者常于40~65岁出现行走困难,临床表现类似早发型,但双下肢肌无力、深感觉障碍、括约肌障碍更常见。二为复杂型HSP,临床上较少见,除痉挛性截瘫表现外,常伴有脊髓病损外的伴发症状体征,遗传异质性更明显。
Ferguson-Critchley综合征:临床特点是中年起病,四肢锥体束征,踝反射减弱或消失,其他腱反射亢进。四肢协调障碍,深感觉略减退。眼部症状主要是眼球震颤,侧向及垂直注视受限,假性眼肌麻痹。锥体外系损害表现四肢僵硬,不自主运动,面部表情少,可有前冲步态。呈常染色体显性遗传。
Kjellin综合征:于20岁左右开始发生痉挛性截瘫,伴小脑性构音障碍,精神运动发育迟滞,视网膜色素变性。呈常染色体隐性遗传。
Mast综合征:起病于20岁左右,痉挛性截瘫,伴有构音障碍,痴呆,手足徐动症。呈常染色体隐性遗传。
Siogren-Larsson综合征:于婴儿期发病,进行性发展,痉挛性截瘫,伴有先天性鱼鳞癣及精神运动发育迟滞。呈常染色体隐性遗传。
Troyer综合征:于儿童早期起病,主要表现为痉挛性截瘫,假性球麻痹,伴有远端肌萎缩、身材短小,到20~30岁不能走路。呈常染色体隐性遗传。
【辅助检查】
1.诱发电位 下肢体感诱发电位(SEPs)显示后索神经纤维传导速度减慢。皮质运动诱发电位显示皮质脊髓束传导速度显著下降。相比而言,上肢诱发电位却是正常的,或仅显示轻度的传导速度减慢。
2.肌电图 可发现失神经改变,但周围神经传导速度正常。
3.MRI 头颅MRI一般无异常,但某些病例可表现胼胝体发育不良,大脑、小脑萎缩。颈段或胸段脊髓MRI可显示脊髓萎缩。
【诊 断】 HSP的诊断主要基于临床症状体征,阳性家族史,并排除其他疾病。因此,HSP的鉴别诊断很重要,特别是对临床特征不典型及没有相同疾病家族史的患者。目前,基因诊断已成为可能,但只限于已克隆的5型疾病基因的突变检测。肌活检有助于 HSP-7型的诊断。
【鉴别诊断】 颈椎病常有上肢受累,神经根性疼痛,颈椎X线片及MRI示颈椎骨质增生。多发性硬化有缓解与复发的病史,视神经炎,MRI示脑部脱髓鞘改变。肌萎缩侧索硬化有上肢肌萎缩,肌束震颤,肌电图示巨大电位改变。Arnold-chiari畸形有共济失调表现,头颅MRI可确诊。脊髓小脑型共济失调以共济失调表现为主,眼球运动障碍,构音障碍等。
【治 疗】目前缺乏特异性治疗方法。但对肢体痉挛状态的治疗是可行的。其他除药物治疗外,肌腱松解术、按摩、理疗、针灸等方法可以减轻痉挛,改善行走困难。
2009年2月11日星期三
致癌物质
黄曲霉素是引起胃癌,肝癌,食道癌的罪魁祸首,它是由发霉的粮食、花生所长出的黄曲霉菌产生的。流行病学调查发现,肝癌多发于温暖、潮湿、容易滋生黄曲霉菌的地区,尤其是食用玉米、花生多的地区。黄曲霉素是由黄霉菌产生的真菌毒素,是目前发现的化学致癌物中最强的物质之一,主要损害肝脏并有强烈的致癌、致畸、致突变作用,目前,国际癌症中心已将黄曲霉毒素定为致癌剂。
胃杀手:亚硝酸盐
亚硝酸盐可导致食道癌和胃癌,它存在于腌制食品中。咸菜,咸肉,酸菜等都含有亚硝酸盐。亚硝胺是硝酸盐还原为亚硝酸盐再与胺结合而成的产物,而硝酸盐及亚硝酸盐均广泛存在于腌酸菜、咸菜、咸鱼、咸肉、烟熏食物中。
蔬菜中含有较多硝酸盐类,煮熟后放置过久,在细菌酶作用下,硝酸盐会还原成亚硝酸盐,与胃内蛋白质分解的产物相作用,形成致癌的亚硝胺。人们在吃了这些剩菜后,易诱发胃癌。另外,调整饮食防胃癌的其他方法有:低盐饮食,可以减少硝酸盐及亚硝酸盐的摄入。而且多吃新鲜蔬菜和水果,其中丰富的维生素C能抑制亚硝酸盐与胺结合。
肺杀手:厨房油烟
当食用油烧到150摄氏度时,其中的甘油就会生成油烟的主要成分丙烯醛,它具有强烈的辛辣味,对鼻、眼、咽喉粘膜有较强的刺激,可引起鼻炎、咽喉炎、气管炎等呼吸道疾病。另外,厨房油烟中含有一种被称为苯并芘的致癌物,苯并芘可导致人体细胞染色体的损伤,长期吸入可诱发肺脏组织癌变。
结肠杀手:油炸食物、高脂肪饮食
建议尽可能避免食用经过长时间高温加工的淀粉类食品,如油炸薯片和油炸薯条和各种油炸食品。,这其中丙烯酰胺含量较高,而丙烯酰胺是一种致癌物。
致癌饮食
茶垢: 茶垢中含有镉、铅、汞、砷等多种有害金属和某些致癌物质,如亚硝酸盐等,可导致肾脏、肝脏、胃肠等器官发生病变。
水果中烂掉的部分: 水果腐烂后,微生物在代谢过程中会产生各种有害物质,特别是真菌的繁殖加快。有些真菌具有致癌作用,可以从腐烂部分通过果汁向未腐烂部分扩散。所以,尽管去除了腐烂部分,剩下的水果仍然不能吃。
用报纸包的食品:油墨中含有一种叫做多氯联苯的有毒物质,它的化学结构跟农药差不多。如果用报纸包食品,它就会渗到食品上,然后随食物进入人体。人体内多氯联苯的储存量达到0.5~2克时会引发中毒。轻者眼皮红肿、手掌出汗、全身起红疙瘩;重者恶心呕吐、肝功能异常、肌肉酸痛、咳嗽不止,甚至导致死亡。
霉变的大米、花生和玉米: 其中含有黄曲霉素,是目前世界上公认的强致癌物质,容易引起肝癌和食道癌。有人以为,多洗几次或高温消毒就能去除有毒物质,其实黄曲霉素一旦污染食物,是很难彻底清除的。
碱性食品中的味精: 味精遇碱性食品会变成谷氨酸二钠,使其失去鲜味;当它被加热到120℃时,会变成致癌物质焦谷氨酸钠。因此,在有苏打、碱的食物中不宜放味精;做汤、菜时,应在起锅前放味精,避免长时间煎煮。
烧焦的鱼和肉: 鱼和肉里的脂肪不完全燃烧,会产生大量的V—氨甲基衍生物,这是一种强度超过了黄曲霉素的致癌物。
腐烂的白菜 : 腐烂和没腌透的白菜中,都含有致癌性亚硝酸盐。
烧烤食品: 所有的烧烤食品中,都容易出现一种致癌能力相当强的物质——苯并芘,这和油炸食品中的油反复使用,所产生的是同一物质。
用卫生纸或毛巾擦过的水果:许多卫生纸的消毒不彻底,携带大肠杆菌、致病性化脓菌、真菌、乙肝病毒等对健康造成影响。
涂在筷子上的油漆: 油漆筷子的使用现在仍然很普遍,但很多人都不知道,这些油漆中含有铅、苯等化学物质,常常随着油漆的剥落被我们吃进体内,造成一定的健康危害。
桌布上的有毒物质: 很多饭店在桌子上铺的薄薄的塑胶桌布是由聚氯乙烯制成的,含有毒的游离基,能通过食具借食物进入体内,导致慢性中毒。所以,在外就餐时,不要将筷子直接放在铺有塑胶薄膜的桌面上。(资料来源:太平洋女性网)
2009年2月10日星期二
糖尿病化验单怎么看
1.尿糖(U—GLU):正常情况下,尿液中只含有微量的葡萄糖,尿糖定性检查呈阴性。当血糖浓度增高到一定程度(≥160~180mg/dl)时,肾小管不能将尿液中的葡萄糖全部回吸收,尿糖增高呈阳性,临床用“+”号表示。一般情况下,尿糖可以反映出血糖的情况,但尿糖还受其他许多因素的影响,因此,有时与血糖并不完全一致。例如,当病人有肾小动脉硬化等肾脏疾病时,由于肾糖阈增高,病人尽管血糖很高,尿糖却往往阴性;再如,妊娠期妇女肾糖阈往往减低,尽管血糖不高,尿糖也可呈阳性。因此,尿糖结果仅供参考,而不能作为诊断的依据。
2.血糖(GLU):临床上所说的血糖是指血液中的葡萄糖。空腹血糖(FPG)的正常值为3.9~6.1mmol/L;空腹血糖≥7.0mmol/L或餐后2小时血糖(P2hPG)≥11.1mmol/L为糖尿病;6.1~7mmol/L为空腹血糖异常(IFG),餐后2小时血糖在7.8~11.1mmol/L为糖耐量异常(IGT),IFG和IGT是界于正常人和糖尿病病人的中间过渡阶段,这样的人是糖尿病的高危人群和后备军,应引起高度重视并及早干预。
3.葡萄糖耐量试验(OGTT):正常人在一次食入大量葡萄糖后,通过体内的各种调节机制的调节,血糖浓度仅为暂时升高,两小时后恢复到正常水平,这是人体的“耐糖现象”。给受试者抽取空腹血标本后,口服75克葡萄糖,然后每隔一定的时间测定血糖含量并画出曲线,即为“糖耐量试验”。正常值:空腹血糖3.9~6.1mmol/L,服糖第一小时后血糖6.7~9.4mmol/L,第二小时后血糖≤7.8mmol/L,第三小时后血糖恢复正常,各次尿糖均为阴性。患糖尿病时,空腹血糖高于正常值,服糖后2小时血糖≥11.1mmol/L。
4.糖化血红蛋白(GHb)和果糖胺(GSP):由于血糖受饮食、活动、药物的影响而波动,因此,测定一次血糖只能反映取血当时的血糖水平,不能反映采血前一段时间血糖情况的全貌。而GHb是血红蛋白与葡萄糖非酶促结合的产物,合成的速度与红细胞所处环境的糖浓度成正比。由于红细胞的寿命是120天,半衰期是60天,故GHb可以反映采血前2~3个月的平均血糖水平,正常值:4%~6%。GSP是葡萄糖与血清蛋白非酶促结合产物,血清蛋白的半衰期短,故GSP仅反映检查前2周的血糖总体控制状况,正常值为1.5~2.4mmol/L。
5.胰岛β细胞功能测定试验:主要用于观察胰岛β细胞的功能状况,协助判断糖尿病型别。通常包括:(1)胰岛素释放试验:口服75克葡萄糖或馒头二两,测定餐前及餐后血浆胰岛素水平。空腹正常胰岛素值为5~15μlU/ml,服糖后1小时上升为空腹的5~10倍,3小时后恢复至空腹水平。1型糖尿病病人胰岛素分泌严重缺乏,餐后胰岛素值分泌也无明显增加;2型糖尿病病人早期空腹胰岛素水平可略高或正常,晚期则往往减低,餐后胰岛素分泌高峰多延迟在2~3小时出现。晚期2型糖尿病病人,由于胰岛β细胞已处于衰竭状态,试验结果可与1型糖尿病相似,此时单靠胰岛素测定来区分1型与2型糖尿病已无意义。
(2)C肽释放试验:C肽是内源性胰岛素最后生成时的等分子离解产物,正常人空腹血浆C肽值为0.8~4.0μg/L。餐后1~2小时增加4~5倍,3小时后基本恢复到空腹水平。本试验的意义与胰岛素释放试验相同。其优点在于,血清C肽测定可以排除外源性胰岛素的干扰,能更准确地反映病人自身胰岛的分泌功能。
6.尿微量白蛋白(MALB):糖尿病患者易并发肾损害,如不及时发现和治疗,会逐渐发展为尿毒症。早期糖尿病肾病,一般化验的尿蛋白常为阴性,易被忽略,待尿中出现蛋白或其他异常时,肾脏病变常不能逆转。尿微量白蛋白测定是反映早期肾损伤的良好指标,如尿中MALB超过30毫克/24小时或20微克/分,则提示有早期肾损害,此时严格地控制血糖并及时用药,肾功能尚可恢复正常。
7.血、尿酮体检查:严重的糖尿病可使酮体在血中堆积,造成糖尿病酮症酸中毒,如不能及时发现和救治,可危及患者生命。尿酮体检查是筛查试验,筛查阳性也可能是由不能进食、呕吐造成的,筛查阴性也可能发生了酮中毒,故准确性较差。可靠的试验是测定血中的β-羟丁酸含量,超过0.5mmol/L提示糖尿病酮症酸中毒。
8.免疫学检查:包括谷氨酸脱羧酶抗体(GA-DA)、胰岛细胞抗体(ICA)和胰岛素自身抗体(IAA)等,主要用于糖尿病的分型。正常人及2型糖尿病病人这三种抗体测定均阴性,而1型糖尿病多呈阳性,其中,GADA最有价值,1型糖尿病患者性率可高达90%,且可持续多年。
2009年1月16日星期五
dream基因和AD的认知改善有关
ScienceDaily (Jan. 15, 2009) — The DREAM gene, which is crucial in regulating pain perception, also seems to influence learning and memory. This is the result of studies carried out by researchers in Seville (Spain) and Vienna (Austria). The new findings could help explain the mechanisms of Alzheimer’s disease and yield a potential new therapeutic target.
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In 2002, a group of scientists at the University of Toronto was able to identify a gene which they dubbed DREAM (downstream regulatory element antagonistic modulator). The gene’s function was highly interesting: it obviously served as a key regulator in the perception of pain. Mice who lacked the gene showed clear signs of markedly reduced sensitivity to all kinds of pain, whether chronic or acute. Otherwise, the mice appeared perfectly normal.
The work leading to these findings was carried out in the lab of Josef Penninger, then principal investigator at the Amgen Institute in Toronto. The publication describing the gene’s function was received with great interest (Cell, Vol. 108, 31-43, 11.1.2002) and DREAM was subsequently termed the “Master-Gene of pain perception”.
Josef Penninger, meanwhile scientific director of IMBA, the Institute of Molecular Biotechnology of the Austrian Academy of Sciences in Vienna, continued to wonder what other surprises DREAM might have in store. In a collaborative effort with neurobiologists from the University Pablo de Olivade (Seville) he devised experiments to follow up on the previous findings. A team of scientists under Ángel Manuel Carrión subjected DREAM-less mice to numerous neurological tests and analyzed their memory skills. The results were striking: without DREAM, mice were able to learn faster and remember better. Fascinatingly, the brains of aged mice (18 months) showed learning capacities similar to those of very young mice.
Thus, DREAM turns out to be a genetic candidate for explaining old age dementia. Even a causal connection to Alzheimer’s disease seems plausible.
Studies published in mid 2008 suggest that the devastating condition may be related to Calcium regulation gone awry. The accumulation of amyloid plaques in brain cells, usually blamed for Alzheimer’s, might be a consequence of the Calcium-imbalance rather than the culprit for the disease.
And Calcium regulation is also responsible for tuning the activity of the DREAM-gene. Calcium homeostasis may thus be the link between pain perception, learning and memory. This is supported by observations of patients suffering from chronic pain: very often their ability to memorize is strikingly reduced and they need a lot more time to learn than individuals without pain.
“It is absolutely fascinating that we found a gene which at the same time regulates pain, learning and old age memory function”, says Josef Penninger, “and it is of great interest to the millions of people suffering from chronic pain that we follow up on these results.”