475 resultados para SARS coronavirus
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It is now 10 years since the disease we now know as SARS-severe acute respiratory syndrome-caused more than 700 deaths around the world and made more than 8,000 people ill. More recently, in 2009 the global community experienced the first influenza pandemic of the 21st century-the 2009 H1N1 influenza pandemic. This paper analyses the major developments in international public health law relating to infectious diseases in the period since SARS and considers their implications for pandemic planning.
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Recent studies have suggested that bats are the natural reservoir of a range of coronaviruses (CoVs), and that rhinolophid bats harbor viruses closely related to the severe acute respiratory syndrome (SARS) CoV, which caused an outbreak of respiratory illness in humans during 2002-2003. We examined the evolutionary relationships between bat CoVs and their hosts by using sequence data of the virus RNA-dependent RNA polymerase gene and the bat cytochrome b gene. Phylogenetic analyses showed multiple incongruent associations between the phylogenies of rhinolophid bats and their CoVs, which suggested that host shifts have occurred in the recent evolutionary history of this group. These shifts may be due to either virus biologic traits or host behavioral traits. This finding has implications for the emergence of SARS and for the potential future emergence of SARS-CoVs or related viruses.
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In the age of air travel and globalized trade, pathogens that once took months or even years to spread beyond their regions of origin can now circumnavigate the globe in a matter of hours. Amid growing concerns about such epidemics as Ebola, SARS, MERS, and H1N1, disease diplomacy has emerged as a key foreign and security policy concern as countries work to collectively strengthen the global systems of disease surveillance and control. The revision of the International Health Regulations (IHR), eventually adopted by the World Health Organization’s member states in 2005, was the foremost manifestation of this novel diplomacy. The new regulations heralded a profound shift in international norms surrounding global health security, significantly expanding what is expected of states in the face of public health emergencies and requiring them to improve their capacity to detect and contain outbreaks. Drawing on Martha Finnemore and Kathryn Sikkink’s "norm life cycle" framework and based on extensive documentary analysis and key informant interviews, Disease Diplomacy traces the emergence of these new norms of global health security, the extent to which they have been internalized by states, and the political and technical constraints governments confront in attempting to comply with their new international obligations. The authors also examine in detail the background, drafting, adoption, and implementation of the IHR while arguing that the very existence of these regulations reveals an important new understanding: that infectious disease outbreaks and their management are critical to national and international security. The book will be of great interest to academic researchers, postgraduate students, and advanced undergraduates in the fields of global public health, international relations, and public policy, as well as health professionals, diplomats, and practitioners with a professional interest in global health security.
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The protein kinases (PKs) belong to the largest single family of enzymes, phosphotransferases, which catalyze the phosphorylation of other enzymes and proteins and function primarily in signal transduction. Consequently, PKs regulate cell mechanisms such as growth, differentiation, and proliferation. Dysfunction of these cellular mechanisms may lead to cancer, a major predicament in health care. Even though there is a range of clinically available cancer-fighting drugs, increasing number of cancer cases and setbacks such as drug resistance, constantly keep cancer research active. At the commencement of this study an isophthalic acid derivative had been suggested to bind to the regulatory domain of protein kinase C (PKC). In order to investigate the biological effects and structure-activity relationships (SARs) of this new chemical entity, a library of compounds was synthesized. The best compounds induced apoptosis in human leukemia HL-60 cells and were not cytotoxic in Swiss 3T3 fibroblasts. In addition, the best apoptosis inducers were neither cytotoxic nor mutagenic. Furthermore, results from binding affinity assays of PKC isoforms revealed the pharmacophores of these isophthalic acid derivatives. The best inhibition constants of the tested compounds were measured to 210 nM for PKCα and to 530 nM for PKCδ. Among natural compounds targeting the regulatory domain of PKC, the target of bistramide A has been a matter of debate. It was initially found to activate PKCδ; however, actin was recently reported as the main target. In order to clarify and to further study the biological effects of bistramide A, the total syntheses of the natural compound and two isomers were performed. Biological assays of the compounds revealed accumulation of 4n polyploid cells as the primary mode of action and the compounds showed similar overall antiproliferative activities. However, each compound showed a distinct distribution of antimitotic effect presumably via actin binding, proapoptotic effect presumably via PKCδ, and pro-differentiation effect as evidenced by CD11b expression. Furthermore, it was shown that the antimitotic and proapoptotic effects of bistramide A were not secondary effects of actin binding but independent effects. The third aim in this study was to synthesize a library of a new class of urea-based type II inhibitors targeted at the kinase domain of anaplastic lymphoma kinase (ALK). The best compounds in this library showed IC50 values as low as 390 nM for ALK while the initial low cellular activities were successfully increased even by more than 70 times for NPM-ALK- positive BaF3 cells. More importantly, selective antiproliferative activity on ALK-positive cell lines was achieved; while the best compound affected the BaF3 and SU-DHL-1 cells with IC50 values of 0.5 and 0.8 μM, respectively, they were less toxic to the NPM-ALK-negative human leukemic cells U937 (IC50 = 3.2 μM) and BaF3 parental cells (IC50 = 5.4 μM). Furthermore, SAR studies of the synthesized compounds revealed functional groups and positions of the scaffold, which enhanced the enzymatic and cellular activities.
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Severe acute respiratory syndrome (SARS) is a serious disease with many puzzling features. We present a simple, dynamic model to assess the epidemic potential of SARS and the effectiveness of control measures. With this model, we analysed the SARS epidemic data in Beijing. The data fitting gives the basic case reproduction number of 2.16 leading to the outbreak, and the variation of the effective reproduction number reflecting the control effect. Noticeably, our study shows that the response time and the strength of control measures have significant effects on the scale of the outbreak and the lasting time of the epidemic.
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The feeding methods of macrothricids was investigated in three species — Ophryoxus gracilis G.O. Sars, Ilyocryptus sordidus (Lievin) and Lathonura rectirostris O.F.Muller. The procuring of food in those species follows two methods: filtration of dispersed particles or scraping off and collecting food from the surface of the substrate. When collecting food by scraping off is the sole method of feeding (as in Lathonura rectirostris), movement along the substrate and feeding are combined so intimately that they appear as parts of one and the same mechanism.
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In species of Cladocera not forming ephippia, the latent eggs have a sheath formed by glands of the reproductive canals. Representatives of the families Daphniidae and Moinidae Goulden, 1968, in connection with the formation of their complex-structured ephippia, lost these glands. It was investigated whether there are such glands in species the latent eggs of which are enclosed in primitive ephippia. For this, with the help of histological methods, 55 females of Acroperus elongatus (Sars) (Chydoridea) and 88 females of Lathonura rectirostris (O. F. Muller), (Macrothricidae) were collected near Leningrad, were studied.
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Background: Recent studies have clearly demonstrated the enormous virus diversity that exists among wild animals. This exemplifies the required expansion of our knowledge of the virus diversity present in wildlife, as well as the potential transmission of these viruses to domestic animals or humans. Methods: In the present study we evaluated the viral diversity of fecal samples (n = 42) collected from 10 different species of wild small carnivores inhabiting the northern part of Spain using random PCR in combination with next-generation sequencing. Samples were collected from American mink (Neovison vison), European mink (Mustela lutreola), European polecat (Mustela putorius), European pine marten (Martes martes), stone marten (Martes foina), Eurasian otter (Lutra lutra) and Eurasian badger (Meles meles) of the family of Mustelidae; common genet (Genetta genetta) of the family of Viverridae; red fox (Vulpes vulpes) of the family of Canidae and European wild cat (Felis silvestris) of the family of Felidae. Results: A number of sequences of possible novel viruses or virus variants were detected, including a theilovirus, phleboviruses, an amdovirus, a kobuvirus and picobirnaviruses. Conclusions: Using random PCR in combination with next generation sequencing, sequences of various novel viruses or virus variants were detected in fecal samples collected from Spanish carnivores. Detected novel viruses highlight the viral diversity that is present in fecal material of wild carnivores.
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The marine invertebrates of North America received little attention before the arrival of Louis Agassiz in 1846. Agassiz and his students, particularly Addison E. Verrill and Richard Rathbun, and Agassiz's colleague Spencer F. Baird, provided the concept and stimulus for expanded investigations. Baird's U.S. Commission of Fish and Fisheries (1871) provided a principal means, especially through the U.S. Fisheries Steamer Albatross (1882). Rathbun participated in the first and third Albatrossscientific cruises in 1883-84 and published the fist accounts of Albatross parasitic copepods. The first report of Albatross planktonic copepods was published in 1895 by Wilhelm Giesbrecht of the Naples Zoological Station. Other collections were sent to the Norwegian Georg Ossian Sars. The American Charles Branch Wilson eventually added planktonic copepods to his extensive published works on the parasitic copepods from the Albatross. The Albatross copepods from San Francisco Bay were reported upon by Calvin Olin Esterly in 1924. Henry Bryant Bigelow accompanied the last scientific cruise of the Albatross in 1920. Bigelow incorporated the 1920 copepods into his definitive study of the plankton of the Gulf of Maine. The late Otohiko Tanaka, in 1969, published two reviews of Albatross copepods. Albatross copepods will long be worked and reworked. This great ship and her shipmates were mutually inspiring, and they inspire us still.
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本文描述了采自四川等省的、我国首次发现的4个枝角类亚种,即美弧网纹溞Ceriodaphnia pulchella pseudohamata Bowkiewcz,1925,西方笔纹溞Graptoleberis testudinaria occidentalis Sars,1901,无常平直溞Pleuroxus laevis incertus Brehm,1934以及宽尾平直潘P.aduncus latic-audatus Brehm,1933。解剖观察描述了盘肠溞科枝角类的头孔,并首次将我国淡水枝角类的分类
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<正> 介形类是底栖的切甲类甲壳动物,部分种类的触角上具有发达的游泳刚毛,所以在通常采到的浮游生物标本中亦很常见。早在1903年,G.O.Sars 氏曾经报导过采自我国的介形类共三属五新种。1923年,V.Brehm 也报导过采自我国广州、北京、四川等地的数种介形类,其中还有一新属,三新种及一新变种。
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<正> 秀体溞(Diaphanosoma)是枝角类栉足族仙达溞科(Sididae)中包括种类最多的一个属,根据已往的记录,共计约有20种。关于我国秀体溞的计载,总共只有7种。最早是由 Spandl 在广东记述了镰角秀体溞(D.excisum Sars)一种。上野益三曾发表过有关我国枝角类的文章多篇,他报告了浙江、四川、台湾、黑龙江、吉林以及内蒙古等地的秀体溞共有6种,即:短尾秀体溞[D.brachyurum(Liévin)],长肢秀体溞
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药物分子与生物分子的相互作用是分子水平上研究药物构效关系及药物筛选的基础。测定形成的非共价复合物及其稳定性是研究药物与靶分子相互作用的关键。单链和双链DAN与小分子的相互作用提供了包括抗癌、抗病毒及抗菌在内的大量治疗药物的作用机理。本论文选择合成了与SARS病毒和肿瘤相关的寡聚核昔酸靶分子,利用质谱高灵敏、专一性、快速、化学计量的特点,研究靶分子与临床上确有疗效的抗病毒、抗肿瘤中药中几大类化学成分的相互作用,探讨它们相互作用的规律,通过相互作用强度的比较,考察这些中药化学成分在抗病毒、抗肿瘤方面的可能活性。在单链寡聚核营酸靶分子(RNA,DNA)与皂昔类化合物的相互作用的研究中,首先建立了区分皂普类异构体的高分辨电喷雾质谱及多级串联质谱的分析方法,通过皂普准分子离子在CID谱中产生的碎片离子,可以提供皂昔昔元、糖基类型、糖链的连接位点,为类似化合物的异构体的区分提供了一个简捷、灵敏、准确的分析方法。考察了实验条件对单链寡聚核营酸靶分子(RNA,DNA)与中药化学成分相互作用的影响;在皂营、黄酮类化合物与单链寡聚核昔酸靶分子的作用研究中,发现非共价作用强度的大小与普元、糖链的结构有关,包括昔元的类型、轻基的数目、糖链的长短,以及糖链上甲基取代的位置。单链寡聚核普酸靶分子与生物碱的相互作用研究表明,相互作用亲和力的大小与生物碱的碱性强弱有关,季胺型生物碱的作用最强,如巴马汀、药根碱、小巢碱与靶分子均生成了较强的非共价复合物。与昔类、内酩、酚类等成分的相互作用同样与其结构密切相关。双链DNA与生物碱类化合物的相互作用研究发现,它们与生物碱的作用强度与双链DNA的AF碱基对富有或GC-碱基对富有有关,且复合物离子的CID断裂途径不同。生物碱化合物的结构不同,其作用强度存在较大差异。述研究结果建立了核昔酸与中药化学成分相互作用研究的软电离质谱方法,利用该方法的研究结果,可以为中药活性成分的初步筛选提供一条可以借鉴的途径。
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1. 中国一个轴前多指 II/III 型家系候选基因的定位 轴前多指(PPD)是人类众多肢体异常症状中比较常见的一种。前人的研 究把它定位到染色体7q36 上450Kb 的区段内。在这个候选区段内,不同的遗传 背景的几个多指家系的致病突变已被发现,它们位于SHH 基因的顺式调控元件 (ZRS)上,这个调控元件调控SHH 正常的时空表达,对指/趾的正常发育起着 重要的作用。在本研究之中,我们分析了我国一个大的多指家系,这个家系的多 指疾病的遗传方式是常染色体显性遗传并有接近100%的疾病外显率。通过连锁 分析和单倍型构建,我们把这个家系的致病基因定位到染色体7q36 上微卫星标 记D7S2465 和 D7S2423 之间1.7cM 的区域内,这个区域包含了上述的450Kb。 为了确定这个家系的致病突变,我们采用了直接测序的方法,筛查了我们定位的 这个区段内的5 个基因(HLXB9, C7orf2, NOM1, RNF32 和C7orf4)的编码区, SHH 基因的ZRS,C7orf2 基因的第5 内含子,和18 个在多物种中保守的非编码 区段(CNS)。我们的结果表明,在这个中国多指家系中,不是上述的5 个基因 和18 个多物种中保守非编码区段(CNS)的突变导致了多指的表型,也不是其 他研究小组报道的SHH 基因的ZRS 突变导致了多指表型。是否在我们界定的这 1.7cM 的候选区段内还存在着SHH 基因的其他调控元件,它的突变也一样会引 起SHH 基因异常的时空表达,最终导致多指表型的产生还需要进一步的研究来 证实。 2. 中国一个单纯性小眼球家系致病基因的定位 先天性小眼球是一种在临床上具有异质性的眼球发育异常疾病,表型从单 侧眼球体积变小到两侧眼球组织的完全缺失。单纯性小眼球疾病指的是除了眼球 的异常不伴随身体其他组织的异常,其遗传学上的致病机理到目前为止还未完全 清楚。之前的研究表明,不同遗传背景的小眼球家系的致病基因被定位到完全不 同的染色体区段上。本研究中的这个中国单纯性小眼球家系,具有常染色体显性的遗传方式,而且是第一个在分子水平上被研究的中国小眼球家系。为了研究这 个家系的致病基因,我们使用了382 个微卫星标记对这个家系进行了全基因组的 扫描,结果表明这个中国小眼球家系的致病基因定位于2 号染色体长臂上,这个 结果不同于以往报道的任何其他小眼球家系。两点连锁分析在重组率为0 时在微 卫星标记D2S2265 上得到最大值3.290,单倍型分析表明所有的受累个体在染色 体2q11-14 上微卫星标记D2S1890 和 D2S347 之间共享相同的单倍型,所以将 这个家系的致病基因定位到染色体2q11-14 上15 cM 的区段内。我们的结果进一 步提示了小眼球疾病的遗传异质性,并且定位了一个新的关于眼球发育的相关基 因。 3. 19 号染色体C 型凝集素家族与中国南方汉族人群的SARS 易感性研究 2003 年SARS 在全球爆发时,不同的个体在感染后表现出不同的病程和 最终的治疗结果,这被认为是个体本身的遗传因素在这个过程中起了一定的作 用,即不同个体在一些基因上的多态影响了他们对一些疾病的易感性。CD209L 基因是19 号染色体上C 型凝集素家族中的一员,它被证明是SARS 病毒的受体, 并且它的第4 外显子的VNTR 多态被认为和宿主对病毒的易感性有关。但是这 个结论在其后其他两个研究小组的工作未被得到证实。可能的原因有:(1) CD209L 基因本身的多态和宿主对SARS 病毒的易感性无关,而是和它紧密连锁 的其它基因的多态发挥真正的作用;(2)可能是由于以前未检测到的群体分层现 象的存在,使最初的研究得到了一个假阳性的结果。为了探讨这个问题,我们对 19 号染色体上C 型凝集素家族的4 个成员(FCER2, CLEC4G, CD209 和 CD209L) 作了全面的研究,我们采用了检测tagSNPs 的方法,在C 型凝集素家族基因簇上 选取了23 个tagSNPs 位点来代表这个基因簇的多态。我们检测了来自中国香港 的181 个SARS 病人和172 个匹配的正常对照,结果表明C 型凝集素家族的4 个基因跟中国南方汉族群体对SARS 病毒的易感之间没有相关性。同时我们检测 了来自中国不同地区的1145 个汉族样本CD209L 基因VNTR 的多态分布情况, 结果表明这个位点在中国人群中存在群体分层现象,这也解释了之前的研究小组 得到的假阳性结果可能正是由于他们忽略了这个问题而导致的
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翼手类(Order Chiroptera)是现生哺乳动物中唯一真正具有空中飞翔能力的动物;同时,它也是哺乳动物中为数不多的具有回声定位功能的几个分类类群之一。现存的翼手目动物约有1100种,占整个哺乳动物种类的20%以上,是哺乳动物中仅次于啮齿目的第二大目。尽管对于翼手目系统发育已经进行了大量的形态学和分子系统学等方面研究,但是翼手目中主要类群的系统发育关系尚存在着许多争议。进化过程中发生的染色体重排在揭示物种的系统发育关系中起到非常重要的作用。种间染色体涂色可以准确、快速、直观地鉴定物种进化过程中发生的大规模染色体重排,已成为在全基因组水平上比较研究哺乳动物核型多样性及其起源和演化的首选方法。利用染色体涂色可以构建不同物种间的比较染色体图谱,通过分析进化过程中保守的染色体片段在不同类群物种核型中的分布和排列方式,可以推导各类群可能的祖先核型,并重建伴随物种形成所发生的基因组变化历史,包括染色体重排的类型、速率和核型演化的趋势。但是,目前关于翼手目染色体涂色研究还很少,至今仍不能为翼手目各级分类水平上的系统发育关系研究提供系统完整的细胞遗传学证据。本研究利用大鼠耳蝠染色体特异涂色探针,通过种间染色体涂色,首次构建了狐蝠科、菊头蝠科、蹄蝠科和蝙蝠科代表物种间的比较染色体同源图谱,并且将它们与之前发表的用人的染色体探针构建的比较染色体图谱进行整合。通过分析这些物种之间保守染色体片段的分布,推测翼手目动物在核型进化过程中所发生的染色体重排的类型和数量,以期为研究翼手目的系统发育关系提供细胞遗传学证据。研究结果表明: 1. 翼手目动物的大多数染色体臂具有高度保守性,罗伯逊易位是其核型进化的主要机制。此外,倒位也是翼手目染色体进化过程中常见的染色体重排方式。 2. 小蝙蝠亚目的菊头蝠科和蹄蝠科与大蝙蝠亚目的狐蝠科亲缘关系更为接近,而与小蝙蝠亚目其它科的亲缘关系较远。 3. 菊头蝠科和蹄蝠科应该各自作为独立的科,但这两个科拥有一个共同的细胞遗传学衍生特征,这一特征在翼手目其它科中并未发现,表明它们之间有非常紧密的系统发育关系。 4. 菊头蝠科的祖先核型可能并不是前人所推测的全由端着丝粒染色体构成的2n=62的核型;很有可能是包含有双臂染色体的,2n低于62的核型。 5. 三叶小蹄蝠比中蹄蝠保留更多的祖先染色体特征,其核型蹄蝠科中较为原始的核型。 6. 着丝粒融合是蝙蝠科物种核型演化的主要机制。蝙蝠科的祖先核型并不是类似于2n=44鼠耳蝠的核型,而可能更类似于棕蝠的2n=50核型,由全端着丝粒染色体构成。 7. 除着丝粒融合外,异染色质的扩增也是蝙蝠科扁颅蝠属和山蝠属的染色体进化方式之一。 8. 绒山蝠与三种亚洲的伏翼共有两个同源染色体片段联合(MMY 8+11和9+13),提示蝙蝠科的山蝠属和伏翼属有非常紧密的亲缘关系。 9. MMY 9 + 23和MMY 18+19 这两个保守的同源染色体片段联合是蝙蝠科扁颅蝠属的细胞遗传学鉴定特征。 通过翼手目这些动物的染色体涂色研究,我们不但在全基因组的水平上揭示了翼手目几个主要类群代表动物的核型系统发育关系,而且所构建的比较染色体图谱将有助于基因组的序列信息从已测序物种(人)向序列信息较少的翼手目物种转移,这些研究结果也可以为翼手目的分类、物种鉴定、系统发育关系和生物医学研究(如SARS病毒)等提供基础性资料。