Ultra-violet radiation is responsible for the differences in global epidemiology.pdf 英国伦敦大学圣乔治医院的病毒学家认为,从另外一个角度来审视目前的证据的话,太阳紫外线能够使皮肤表面的水痘病毒在传染给其他人之前灭活,这也解释了为什么热带国家水痘的传播较弱的原因。上周 PhilRice 博士在面对采访时告诉媒体他希望他的发现能够为水痘和带状疱疹的预防提供一条新的途径,带状疱疹与水痘关系密切,且比水痘更严重。紫外线能够灭活病毒并不是一个新的观点,但这项研究首次对紫外线灭活水痘带状疱疹病毒得出确切的结论,疱疹病毒是水痘和带状疱疹的病原体。这项研究的结果发表在今年早期的病毒学杂志。Rice 阐述了与紫外线强度较低的地区比较,紫外线强度较高的地区水痘流行的减弱的程度,以及为何在温带地区水痘的流行高峰分布在冬春季节,而此时紫外线强度是最低的。这项研究结果对目前广泛接受的观点提出了挑战,目前认为水痘流行的地区差别其他一些因素引起,包括由于人口密度、温度、湿度以及感染其他能够免疫水痘和带状疱疹的病毒。在研究中,Rice 对 25 项关于水痘带状疱疹病毒患病率的研究所得出的证据进行了分析。这些研究对世界范围内的温带和热带地区水痘的疾病模式进行了研究。他对水痘流行模式中与气候相关的一系列因素进行分析以寻找哪一个因素与他们相关性最强。在排除其他因素后,他发现在每个被研究的国家,只有紫外线与水痘的感染模式高度相关。 Rice 指出:“之前没有人认为紫外线是水痘流行的一个影响因素,但当我们对流行病学研究进行评价时,这些研究表明纬度和病毒的存在高度相关。”他说促使他相信上述结论的原因是无论在何时在数据中发现异常,总能找到一种言之有理的解释。例如,印度和斯里兰卡水痘的发病高峰是在炎热、干燥、日照强烈的季节。起初你可能认为此时紫外线强度最大,进而否认上述关联,但实际并非如此:“... 实际上与季风季节相比,紫外线强度在干燥季节明显降低,大气污染将紫外线接触我们之前将其反射或太空。但在季风季节,降雨将污染物清洗,这也就意味着紫外线可以通过大气,”他解释道。Rice 的发现似乎也阐明了为何水痘带状疱疹病毒存在两种完全不同的基因型:一种适合温带气候,而另外一种适合热带气候。他发现在温带流行的病毒基因型只能在紫外线强度减弱或受到屏蔽的情况下才能传播。例如,在室内可以传播,但在户外并不传播。但即使在紫外线存在的情况下,在热带流行的病毒基因型似乎也能传播。Rice 认为热带基因型病毒已经对紫外线产生抗性,并且这种抗性在温带区域已经消失,这使得之前就已经阻断了从热带向温带的传播。但除非病毒在失去一种优势时能获得更多好处,否则他们不能生存。Rice 猜想热带病毒在失去紫外线抗性的同时也变得更易复活,正如带状疱疹一样。他认为:“病毒不能同时拥有这两种优势,只能具有其中一种。这可能解释了为什么在热带地区人群中带状疱疹流行强度更弱,而在温带地区的病毒较热带病毒更易复活”目前的水痘疫苗是在上世纪 70 年代研制成功的,当时我们并知道水痘带状疱疹病毒有两种基因型。 Rice 相信这些结果有助于发现新的治疗水痘和带状疱疹的方法,并且需要开展更多的研究来分析紫外线灭活病毒的根本机制。得过水痘的人仍可能得带状疱疹,这种疾病是带状疱疹病毒感染引起的一种以沿神经分布的群集疱疹和神经痛为特征的病毒性皮肤病。尽管带状疱疹多发生于 50 岁以后,此时免疫系统可将病毒局限于颈部使其致病性降低,但目前认为约 1/5 的曾经得过水痘的人以后仍会发展成带状疱疹,在时时间较长的疾病后或精神压力较大时可引发带状疱疹发作。 http://infect.dxy.cn/article/17101?keywords=核酸紫外 论文全文: Ultra-violet radiation is responsible for the differences in global epidemiology.pdf
An article published in Comprehensive Reviews in Food Science and Food Safety examines the effects of UV light and HPP processing on nutritional and quality-related compounds in juice products. For a fast growing category of premium juice products such as cold-pressed juices, minimal-processing nonthermal techniques such as ultraviolet (UV) light and high-pressure processing (HPP) are expected to be used to extend shelf life while retaining physicochemical, nutritional, and sensory characteristics with reduced microbial loads. Also, UV light and HPP are approved by regulatory agencies and recognized as one of the simplest and environmentally-friendly ways to destroy pathogenic organisms. However, a limitation to their more extensive commercial application lies in the lack of comparative effects on nutritional and quality-related compounds in juice products. In this review, the authors provide a comparative analysis using 92 studies (UV light: 42, HPP: 50), published between 2004 and 2015, to evaluate the effects of reported UV light and HPP processing conditions on the residual content or activity of bioactive compounds such as vitamins, polyphenols, antioxidants, and oxidative enzymes in 45 different fresh fruit and vegetable juices (low-acid, acid, and high-acid categories). In addition, the authors summarize and discuss the effects of UV light and HPP on color and sensory characteristics of juices. Through their review the authors determined that both processing methods—UV light and HPP—showed only minor degradation of juice physicochemical properties, vitamin content, and antioxidant activity at conditions required to achieve 5-log reduction of pathogenic microorganisms. However, over-processing was common among all the studies—often leading to an unnecessary decrease in quality and nutritional parameters.
颁奖典礼上,几个北欧人好像把DNA修复说成很简单的事情:无论是紫外,还是吸烟带来的DNA破坏,人体都有机制修复它。问题是,很多人就是因为紫外或者吸烟获得皮肤癌或者肺癌。 他们的视频可能误导多少烟鬼啊! DNA修复的局限性没有被观众问到,而2个来自中国的记者浪费时间问了2个答案明显的问题。哪个单位的? 对DNA修复机制的局限性深入研究,也许能帮助人们寻找治疗癌症等疾病的良药。或许导致以后获得炸药奖。 【补充:倒是其官方资料提及DNA修复的局限和相关的药物研发。】 http://www.nobelprize.org/nobel_prizes/chemistry/laureates/2015/popular-chemistryprize2015.pdf 。。。 Our genome would collapse without these repair mechanisms. If just one component fails, the genetic information changes rapidly and the risk of cancer increases. Congenital damage to the nucleotide excision repair process causes the disease xeroderma pigmentosum; individuals who suffer from this disease are extremely sensitive to UV radiationand develop skin cancer after exposure to the sun. Defects in DNA mismatch repair increase the risk ofdeveloping hereditary colon cancer , for instance.In fact, in many forms of cancer, one or more of these repair systems have been entirely or partiallyswitched off. This makes the cancer cells’ DNA unstable, which is one reason why cancer cells oftenmutate and become resistant to chemotherapy. At the same time, these sick cells are even more dependenton the repair systems that are still functioning; without these, their DNA will become too damaged and thecells will die. Researchers are attempting to utilise this weakness in the development of new cancer drugs.Inhibiting a remaining repair system allows them to slow down or completely stop the growth of the cancer. One example of a pharmaceutical that inhibits a repair system in cancer cells is olaparib . ( https://en.wikipedia.org/wiki/Olaparib )
在众多癌症类型中,皮肤癌是最常见的类型之一。美国人一生中患皮肤癌的风险几率高达20%。大多数皮肤癌是由太阳光紫外线直接损伤DNA,引起C→T和CC→TT突变,形成环丁烷嘧啶二聚体所造成。 传统认为,环丁烷嘧啶二聚体中胞嘧啶或5’甲基胞嘧啶迅速脱氨基形成尿嘧啶或胸腺嘧啶是皮肤癌基因突变的机制;而且普遍认为一旦离开太阳光,紫外线的损伤就会停止。 但是,华盛顿大学的学者在《科学》杂志3月份刊出的最新研究结果证明,事实并非如此。即使避开阳光,紫外线通过其他途径,仍然持续损伤皮肤细胞的DNA。这一重大研究结果揭示了黑色素瘤的形成机制。 美捷登:Mike 原文信息 Chemiexcitation of melanin derivativesinduces DNA photoproducts long after UV exposure Science20 February 2015: Vol. 347 no. 6224 pp. 842-847 Mutations in sunlight-induced melanomaarise from cyclobutane pyrimidine dimers (CPDs), DNA photoproducts that aretypically created picoseconds after an ultraviolet (UV) photon is absorbed atthymine or cytosine. We found that in melanocytes, CPDs are generated for 3hours after exposure to UVA, a major component of the radiation in sunlight andin tanning beds. These “dark CPDs” constitute the majority of CPDsand include the cytosine-containing CPDs that initiate UV-signature C→T mutations. Dark CPDs arise when UV-induced reactive oxygen andnitrogen species combine to excite an electron in fragments of the pigmentmelanin. This creates a quantum triplet state that has the energy of a UVphoton but induces CPDs by energy transfer to DNA in a radiation-independentmanner. Melanin may thus be carcinogenic as well as protective against cancer.These findings also validate the long-standing suggestion that chemicallygenerated excited electronic states are relevant to mammalian biology. 原文链接: http://www.sciencemag.org/content/347/6224/842.abstract 美捷登版权www.medjaden.com欢迎转载,转载请勿修改内容 欢迎关注我们的微信
氢气生理盐水对紫外线 B 皮肤损伤的保护作用 南京医科大学第一附属医院皮肤科最近的研究发现,氢气可以对抗紫外线引起的皮肤损伤,文章发表在 J Biomed Res. (原南京医科大学学报)上。 众所周知,太阳来源的紫外线可以引起皮肤损伤,其中紫外线 B ( UVB )辐射诱导皮肤产生的活性氧( ROS )是导致损伤的重要原因,氢气具有抗 ROS 氧化损伤和抗炎症作用。在本研究中,我们试图证明,富氢生理盐水是否具有保护紫外线辐射皮肤损伤的效果。 选择 C57BL/6 雌性小鼠,经 UVB 辐射照射引起皮肤损伤为疾病模型。给予小鼠腹腔注射富氢生理盐水和富氮生理盐水。显微镜检测伤后皮肤损害。 UVB 辐射后肿瘤坏死因子 α ,白介素( IL ) -1β 和 IL-6 等炎症因子显著升高,组织超氧化物歧化酶降低,丙二醛和一氧化氮的活性升高。富氢生理盐水通过改变这些标志物的水平和改善病理改变。结果表明,富氢生理盐水可能通过减少炎症和氧化应激保护皮肤对抗紫外线辐射损伤。 J Biomed Res. 2012 Sep;26(5):365-71. doi:10.7555/JBR.26.20110037. Epub 2012 Apr 24. Hydrogen-richsaline protects against ultraviolet B radiation injury in rats. Guo Z , Zhou B , Li W , Sun X , Luo D . Source Departmentof Dermatology, the First Affiliated Hospital of Nanjing Medical University,Nanjing, Jiangsu 210029, China; Abstract Exposureof skin to solar ultraviolet (UV) radiation induces photo-damage. Ultraviolet B(UVB) is the major component of UV radiation which induces the production ofreactive oxygen species (ROS) and plays an important role in photo-damage.Hydrogen gas reduces ROS and alleviates inflammation. In this study, we soughtto demonstrate that hydrogen-rich saline has the effect on skin injuries causedby UVB radiation. UVB radiation was irradiated on female C57BL/6 rats to induceskin injury. Hydrogen-rich saline and nitrogen-rich saline were administered torats by intraperitoneal injection. Skin damage was detected by microscope afterinjury. UVB radiation had a significant affection in tumor necrosis factoralpha, interleukin (IL)-1β and IL-6 levels, tissue superoxide dismutase,malondialdehyde and nitric oxide activity. Hydrogen-rich saline had aprotective effect by altering the levels of these markers and relievedmorphological skin injury. Hydrogen-rich saline protected against UVB radiationinjury, possibly by reducing inflammation and oxidative stress. KEYWORDS: