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维生素D和老年痴呆症

    英国埃克塞特大学研究团队首次确立维生素D缺乏和认知问题间清晰的关联。这一由David J. Llewellyn博士领导的研究发现发表在有声望的《内科学档案》杂志上,它是一个国际性合作的结果。

    维生素D是一种脂溶性的维生素,它存在于诸如多油脂的鱼等几种食物中。它也可作为一种食品补充剂。维生素D主要是在皮肤接触日光中的紫外光线后产生的。然而,随着年龄变老,人的皮肤产生维生素D的效率降低。大多数的在欧洲和美国的老年人的维生素D的水平都不足。人们对维生素D的兴趣最近有所增强,因为研究人员发现,它在范围广泛的诸如癌症、心脏病及中风等与衰老有关的疾病中可能扮演着一个重要的角色。

    该项研究中包括了在1998年至2006年期间参加了InCHIANTI研究的生活在意大利的850多名老年人(他们的年龄为65岁或以上)。每一位参与者的认知功能都用标准的测定方法进行了评估,这些方法有一般认知能力(MMSE)、心智灵活性及心智速度。与具有健康维生素D水平的参与者相比,那些维生素D严重缺乏者感受到显著的总体认知水平衰退的可能性会增加60%,感受到新发心智灵活性问题的可能性会增加31%。

    据估计,全世界有10亿人有维生素D不足的问题,所以这是一个非常令人担忧的原因。很少有食物含有维生素D,在纬度偏北地区的一年中,在大多数的时间内无法靠阳光来合成维生素D,而且随着年龄的衰老,皮肤产生维生素D的效率也有所降低。认知功能的衰退及痴呆在老年人中也很常见,尽管人们对其基础原因大体上仍然不清楚,而目前的用于预防和治疗的选项也很有限。维生素D因此是一种十分有希望的预防痴呆症的治疗标靶,特别是它作为补充剂价格便宜、安全而且它已经显示了具有减少跌倒、骨折和死亡风险的功效。

天下美食   麻辣烫配方   珍珠奶茶   四季食补   凉茶配方

Arch Intern Med. 2010;170(13):1135-1141. doi:10.1001/archinternmed.2010.173

Vitamin D and Risk of Cognitive Decline in Elderly Persons
David J. Llewellyn, PhD; Iain A. Lang, PhD; Kenneth M. Langa, MD, PhD; Graciela Muniz-Terrera, PhD; Caroline L. Phillips, MS; Antonio Cherubini, MD; Luigi Ferrucci, MD, PhD; David Melzer, PhD

Background  To our knowledge, no prospective study has examined the association between vitamin D and cognitive decline or dementia.

Methods  We determined whether low levels of serum 25-hydroxyvitamin D (25[OH]D) were associated with an increased risk of substantial cognitive decline in the InCHIANTI population–based study conducted in Italy between 1998 and 2006 with follow-up assessments every 3 years. A total of 858 adults 65 years or older completed interviews, cognitive assessments, and medical examinations and provided blood samples. Cognitive decline was assessed using the Mini-Mental State Examination (MMSE), and substantial decline was defined as 3 or more points. The Trail-Making Tests A and B were also used, and substantial decline was defined as the worst 10% of the distribution of decline or as discontinued testing.

Results  The multivariate adjusted relative risk (95% confidence interval [CI]) of substantial cognitive decline on the MMSE in participants who were severely serum 25(OH)D deficient (levels <25 nmol/L) in comparison with those with sufficient levels of 25(OH)D (75 nmol/L) was 1.60 (95% CI, 1.19-2.00). Multivariate adjusted random-effects models demonstrated that the scores of participants who were severely 25(OH)D deficient declined by an additional 0.3 MMSE points per year more than those with sufficient levels of 25(OH)D. The relative risk for substantial decline on Trail-Making Test B was 1.31 (95% CI, 1.03-1.51) among those who were severely 25(OH)D deficient compared with those with sufficient levels of 25(OH)D. No significant association was observed for Trail-Making Test A.

Conclusion  Low levels of vitamin D were associated with substantial cognitive decline in the elderly population studied over a 6-year period, which raises important new possibilities for treatment and prevention.

娃娃脸的人容易长寿

    南丹麦大学的凯尔·克里斯滕森教授最近指出,长着一张娃娃脸的人意味着他/她将享受更长的寿命,因为人们的生活状况很容易反映在脸上。

    凯尔教授领导的研究小组以双胞胎为研究对象,看看外表年龄(也就是别人认为你有多大)与你的生存能力、身体机能和智力有着何种联系。这项研究始于2001年春季开始,研究者对1826对70岁以上的丹麦双胞胎进行了体能和认知测试,并拍了他们的面部照片。三名评审员在不知道他们年龄范围的情况下对不同年龄组的双胞胎进行年龄评估,结果发现,即使是双胞胎,被猜出的年龄也相差很大。研究者然后用7年时间对这些双胞胎的晚年生活进行了跟踪调查,直至他们去世。调查表明:双胞胎中,外表年龄差异越大,看起来老的那个就越有可能先死。该研究报告发表在英国《医学杂志》上。

天下美食   麻辣烫   珍珠奶茶   四季食补   凉茶配方

    凯尔教授还研究了寿命是否与染色体终端有关,发现染色体的状态与生命老化有直接关系,就如同鞋带末端上的塑料帽一样,这些染色体末端由于细胞分裂而不断损耗,这是一个自然老化的进程。染色体上端粒较短的人更容易患上与年龄增长相关的病症,死亡时间也会更早。端粒较长意味着你更年轻、更健康。但他认为端粒测试太复杂,不如看外表来得简单。外表年龄是每个人生活环境、性生活、生活状况和心态的集中体现。

    Synvista于2009年1月28宣布,经过其临床发展的产品组合以及目前的财务状况的审查,对董事会和管理层决定了它在公司的最大利益是把重点放在最大限度地提高其诊断资产的价值和资源,终止其所有候选产品(alagebrium和SYI-2074)正在进行的临床试验,其中包括以下内容:

  • BENEFICIAL研究,这是第2期双盲,安慰剂对照,随机试验,alagebrium治疗慢性收缩性心力衰竭病人;
  • BREAK研究,这是第2期双盲,安慰剂对照,随机试验,alagebrium治疗舒张性心力衰竭病人;
  • SYI-2074的第二期外用配方试验,用于治疗成人慢性,轻度至中度银屑病造成的斑块。

    这些试验都将被终止尽可能迅速。

    如前所述,该公司已递交申请的510(k)就其HAPTOCHEK(商标)诊断试剂盒,蛋白质为基础的临床化验检查,以确定与Hp2 - 2型糖尿病患者。90天的此类提交审查过程仍在进行,在此期间,FDA将决定是否工具包可以分布在一个国家实验室体外诊断。

    该公司正继续探讨战略性方案,以货币化的技术资产,这可能需要就这些资产的出售或许可交易的形式。在公司的现金状况和当前不利的经济和资本市场的条件下,如果公司无法及时进入这些交易,该公司能否继续进行的2009年第二季度经营将是一个问题。

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Synvista Therapeutics, Inc. (NYSE Alternext US: SYI) today announced that, following a review of its clinical development portfolio and its current financial status, the Board of Directors and management have determined that it is in the best interest of the Company to focus its resources on maximizing the value of its diagnostic assets and to terminate all ongoing clinical trials of its product candidates alagebrium and SYI-2074, including the following:

  • the BENEFICIAL study, which was a Phase 2 double-blind, placebo-controlled, randomized trial of alagebrium in patients with chronic systolic heart failure;
  • the BREAK study, which was a Phase 2 double-blind, placebo-controlled, randomized trial of alagebrium in patients with diastolic heart failure; and
  • the Phase 2 trial of a topical formulation of SYI-2074 for the treatment of chronic, mild-to-moderate plaque psoriasis in adults.

Each of these trials will be terminated as promptly as possible.

As noted previously, the Company has submitted an application for 510(k) clearance for its HAPTOCHEK(TM) diagnostic test kit, a protein-based clinical laboratory test to identify patients with Hp2-2 diabetes. The 90-day review process of such submission is ongoing, during which time the FDA will determine whether the kit can be distributed to labs throughout the country as an in vitro diagnostic.

The Company is continuing to explore strategic alternatives in order to monetize its technology assets, which may take the form of sales or licensing transactions with respect to those assets. In light of the Company’s cash position and current negative economic and capital markets conditions, if the Company is unable to enter into such transactions in a timely manner, the Company’s ability to continue operations beyond the second quarter of 2009 is in do.

  加拿大的一项最新研究表明,如果女性患病,雌激素就会为其免疫系统提供额外的抵抗力。雌性激素可能阻碍一种酶发挥作用,而这种酶会破坏发炎过程。因此,在战胜疾病方面,并不存在两性平等,女性的免疫系统远远强于男性,这可能就是为什么男性在患上感冒等传染病之后比女性承受更多病痛的原因。

  马娅·萨利赫教授在麦吉尔大学的健康中心领导了此项研究。研究结果显示,女性的发炎反应比男性更强。研究人员在鼠身上对胱冬肽酶-12进行了研究,这种酶的基因能够终止发炎过程。发炎过程是肌体遭遇细菌病毒入侵时的第一道防线。科学家们对缺乏胱冬肽酶-12相关基因的实验鼠进行了研究,缺乏这种基因使它们传染病具有非常强的抵抗能力。随后研究人员在一组包括雌雄两性在内的实验鼠体内植入这种基因,但只有雄性实验鼠变得更易感染疾病。


  萨利赫教授表示:“我们对这种结果感到十分意外,进而推断雌性实验鼠的免疫系统产生的雌激素会阻碍胱冬肽酶-12的相关基因发挥作用。” 科学家们还确定了雌激素附着以阻碍其发挥效力的具体位置,这表明雌激素在这种情况下发挥了直接作用。由于实验中使用的是人类基因,因此科学家认为,此项研究成果也适用于人类。

  研究人员认为,女性之所以能够进化出更强大的免疫系统,是因为她们在生育和抚养后代的过程中扮演至关重要的角色。也许这是大自然的一项策略,旨在维护女性的生育地全和保护人类这一物种。

    美国农业科研局(Agricultural Research Service,ARS)的科学家约瑟夫、苏凯特-海尔和里曼多进行的一项最新研究表明,西红柿、葡萄、草莓、桑椹等蔬菜和水果中含有的化学物质紫檀芪(pterostilbene)具有抗衰老作用,能逆转衰老给机体带来的负面效应。这项研究发表在最近一期的《农业与食品化学杂志》(Journal of Agricultural and Food Chemistry)上。

    美国农业部Jean Mayer人类营养抗衰老研究中心的神经科学家詹姆斯·约瑟夫(James Joseph)、心理学家巴巴拉·苏凯特—海尔(Barbara Shukitt-Hale)以及ARS天然产物应用研究所的艾格尼丝·里曼多(Agnes Rimando)共同完成了这项研究。

    为了证明紫檀芪能否逆转高龄实验小鼠的衰老效应,科学家将研究分为两个部分。在第一部分的实验中,他们在细胞培养实验中测试了7种芪类物质(stilbene,也叫1,2-二苯乙烯),结果发现,紫檀芪预防氧化应激反应(Oxidative Stress,即破坏强氧化剂和抗氧化剂的平衡导致的潜在伤害,氧化剂、抗氧化剂平衡的破坏是细胞损伤的主要原因)的能力最强。第二部分的实验中,科学家把实验小鼠分为3组:第一组为对照组,不喂食紫檀芪;第二组喂食低剂量的紫檀芪,第三组则喂食高剂量的紫檀芪。

    结果表明,高龄小鼠的认知能力、记忆力的改善程度,与大脑海马区的紫檀芪浓度呈正比关系。此前,ARS的科学家已做过多项类似研究,在一定程度上阐明了不同食物构成与大脑功能间的关系。主持上述研究的科学家表示,在浆果(如西红柿、葡萄)中,还含有其他与紫檀芪类似的物质,他们正在做后续的动物与细胞模型研究。

Journal of Agricultural and Food Chemistry,DOI: 10.1021/jf802279h,James A. Joseph,Barbara Shukitt-Hale

Cellular and Behavioral Effects of Stilbene Resveratrol Analogues: Implications for Reducing the Deleterious Effects of Aging

James A. Joseph*, Derek R. Fisher, Vivian Cheng, Agnes M. Rimando and Barbara Shukitt-Hale

Agricultural Research Service, U.S. Department of AgricultureHuman Nutrition Research Center on Aging at Tufts University, 711 Washington Street, Boston, Massachusetts 02111, and Natural Products Utilization Research Unit, Agricultural Research Service, U.S. Department of Agriculture, University, Mississippi 38677

Abstract

Research suggests that polyphenolic compounds contained in fruits and vegetables that are rich in color may have potent antioxidant and anti-inflammatory activities. The present studies determined if stilbene (e.g., resveratrol) compounds would be efficacious in reversing the deleterious effects of aging in 19 month old Fischer 344 rats. Experiment I utilized resveratrol and six resveratrol analogues and examined their efficacies in preventing dopamine-induced decrements in calcium clearance following oxotremorine-induced depolarization in COS-7 cells transfected with M1 muscarinic receptors (MAChR) that we have shown previously to be sensitive to oxidative stressors. Experiment II utilized the most efficacious analogue (pterostilbene) from experiment I and fed aged rats a diet with a low (0.004%) or a high (0.016%) concentration of pterostilbene. Results indicated that pterostilbene was effective in reversing cognitive behavioral deficits, as well as dopamine release, and working memory was correlated with pterostilbene levels in the hippocampus.

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