1、文献（学术论文）阅读 医学学术论文 综述徐州医学院徐州医学院生物学教研室生物学教研室 高殿帅高殿帅综 述 发展的轨迹（线索）现状的总结（归纳）指出存在的问题 提出解决问题的策略不是今天要的内容！有机会再讲。不是今天要的内容！有机会再讲。学术论文是某一学术课题在实验性、理论性或观学术论文是某一学术课题在实验性、理论性或观测性上具有新的科学研究成果或创新见解的知识测性上具有新的科学研究成果或创新见解的知识和科学记录和科学记录；或是某种已知原理应用于实际中取得新进展的科学总结，用以提供学术会议上宣读、交流或讨论；或在学术刊物上发表；或作其他用途的书面文件。学术论文具有四大特点：学术性 科学性 创造性
2、 理论性 医学医学学术论文学术论文 学术论文（科研文章）学术论文的形态结构（格式）传递学术论文信息的语言单位 理解学术论文的三层境界学术论文的形态结构（格式）题名 作者 摘要 关键词 引言 材料与方法 结果 讨论 致谢 参考文献The structure of an article文章的结构文章的结构Authors作者作者 Title题目题目Abstract摘要摘要 Keywords关键词关键词 Main text正文正文 References参考文献参考文献 Supplementary material补充资料补充资料Introduction引言引言 Methods方法方法 Results结
3、果结果 Acknowledgments致谢致谢 Discussion讨论讨论 Clearly describes contents Ensures recognition for the writer/s Describes succinctly what was done Provides supplementary data for the expert reader Ensures previously published work is recognized Ensures the article is correctly identified in abstracting and i
4、ndexing servicesExplains the hypothesis Explains how the data were collected Describes what was discovered Discusses the implications of the findings Ensures those who helped in the research are recognized How to write a scientific article 如何写科学文章如何写科学文章题 名 题名是以最恰当、最简洁的词语反映学术论文中最重要的特定内容的逻辑组合。题名应该具有吸
5、引力。题名举例 Neural stem and progenitor cells retain their potential for proliferation and differentiation into functional neurons despite lower number in aged brain.Radial glia-like cells persist in the adult rat brain.Noggin expands neural stem cells in the adult hippocampus.Upregulation of chemokine r
6、eceptor expression by IL-10/IL-4 in adult neural stem cells.题 名 注意句法结构：完整的句子？特定的词组？注意内容结构：处理因素 实验对象 实验效应（观察指标）Death receptors and caspases but not mitochondria are activated in the GDNF-or BDNF-deprived dopaminergic neurons题名分析摘 要 20世纪60年代国外首先提出科技论文应附摘要，中华医学杂志英文版1972年也提出要求附摘要。20世纪80年代加拿大温哥华一个研究小组进一步
7、提出结构式摘要，即要求摘要写法分成四部分，分别冠以标题，使读者无需查阅正文即可基本了解实质性内容。摘要具有独立性和自含性，即不阅读全文，就能获得必要的信息。摘要一般应说明研究工作目的、材料与方法、结果、结论等，而重点是结果和结论。摘 要 Death Receptors and Caspases But Not Mitochondria Are Activated in the GDNF-or BDNF-Deprived Dopaminergic Neurons Neurotrophic factors,including glial cell line-derived neurotrophic
8、 factor(GDNF)and brain-derived neurotrophic factor(BDNF),promote survival of midbrain dopaminergic neurons,but the death pathways activated in the dopaminergic neurons by deprivation of these factors are poorly studied.We show here that deprivation of GDNF or BDNF triggers a novel mitochondria-indep
9、endent death pathway in the cultured embryonic dopaminergic neurons:cytochrome c was not released from the mitochondria to cytosol,proapoptotic protein Bax was not activated,and overexpressed Bcl-xL did not block the death.Caspases were critically required,because the death was completely blocked by
10、 caspase inhibitor BAF boc-aspartyl(OMe)-fluoromethylketone and overexpression of dominant-negative mutants of caspase-9,-3,and-7 significantly blocked the death.Also,the death receptor pathway was involved,because blockage of caspase-8 or FADD(Fas-associated protein with death domain),an adapter re
11、quired for caspase-8 activation,inhibited death induced by GDNF or BDNF deprivation.Ligation of Fas by agonistic anti-Fas antibody induced apoptosis in the GDNF-or BDNF-maintained neurons,and inhibition of Fas by Fas-Fc chimera blocked the death of GDNF-or BDNF-deprived neurons,whereas FAIML(long is
12、oform of Fas apoptosis inhibitorymolecule)could control the activity of Fas in the dopaminergic neurons.Neurotrophic factors,including glial cell line-derived neurotrophic factor(GDNF)and brain-derived neurotrophic factor(BDNF),promote survival of midbrain dopaminergic neurons,but the death pathways
13、 activated in the dopaminergic neurons by deprivation of these factors are poorly studied.请翻译！凋亡抑制分子的长异构体？请说出该摘要中下列几部分是怎样表达的？目的 材料和方法 结果 结论Death receptors and caspases but not mitochondria are activated in the GDNF-or BDNF-deprived dopaminergic neurons Neurotrophic factors,including glial cell line-
14、derived neurotrophic factor(GDNF)and brain-derived neurotrophic factor(BDNF),promote survival of midbrain dopaminergic neurons,but the death pathways activated in the dopaminergic neurons by deprivation of these factors are poorly studied.We show here that deprivation of GDNF or BDNF triggers a nove
15、l mitochondria-independent death pathway in the cultured embryonic dopaminergic neurons:cytochrome c was not released from the mitochondria to cytosol,proapoptotic protein Bax was not activated,and overexpressed Bcl-xL did not block the death.Caspases were critically required,because the death was c
16、ompletely blocked by caspase inhibitor BAF boc-aspartyl(OMe)-fluoromethylketone and overexpression of dominant-negative mutants of caspase-9,-3,and-7 significantly blocked the death.Also,the death receptor pathway was involved,because blockage of caspase-8 or FADD(Fas-associated protein with death d
17、omain),an adapter required for caspase-8 activation,inhibited death induced by GDNF or BDNF deprivation.Ligation of Fas by agonistic anti-Fas antibody induced apoptosis in the GDNF-or BDNF-maintained neurons,and inhibition of Fas by Fas-Fc chimera blocked the death of GDNF-or BDNF-deprived neurons,w
18、hereas FAIM(L)(long isoform of Fas apoptosis inhibitory molecule)could control the activity of Fas in the dopaminergic neurons.引 言 引言又称前言，属于整篇论文的引论部分。其写作内容包括：研究的背景、现状，存在的问题，提出解决问题的策略（自己的创新点），阐述所提策略的理论依据和实验基础，主要研究内容。引言的文字不可冗长，内容选择不必过于分散、琐碎，措词要精炼，要吸引读者读下去。言简意赅，不要与摘要雷同，不要成为摘要的注释。一般教科书中有的知识，在引言中不必赘述。Mos
19、t neuronal populations undergo a period of ontogenetic death during which the initially overproduced neurons are reduced to the final number by target-derived neurotrophic factors(Barde,1989;Oppenheim,1991).The intrinsic death program of the neurons is suppressed by neurotrophic factors or,conversel
20、y,released in their absence(Johnson and Deckwerth,1993;Chang et al.,2002).The molecular nature of this program is,however,poorly described for different neuronal types.Death receptors and caspases but not mitochondria areactivated in the GDNF-or BDNF-deprived dopaminergic neuronsSurvival of the midb
21、rain dopaminergic(DA)neurons that degenerate in Parkinsons disease is potently promoted by glial cell line-derived neurotrophic factor(GDNF)in vitro(Lin et al.,1993;Burke et al.,1998),in vivo(Oo et al.,2003,2005),and inseveral models of Parkinsons disease(Airaksinen and Saarma,2002;Bespalov and Saar
22、ma,2007;Lindholm et al.,2007).GDNF binds to coreceptor GFR1,and this complex activates receptor tyrosine kinase Ret(Bespalov and Saarma,2007).Genetic manipulations of Ret in the DA neurons(Granholm et al.,2000;Jain et al.,2006;Kramer et al.,2007;Mijatovic et al.,2007)have given controversial results
23、 whether and/or when Ret physiologically regulates survival/death of DA neurons.Treatment of Parkinsons patients with GDNF has also been contradictory,because some studies reported considerable improvement(Gill et al.,2003;Slevin et al.,2005),whereas others did not(Lang et al.,2006).These contradict
24、ions require further studies.Death receptors and caspases but not mitochondria areactivated in the GDNF-or BDNF-deprived dopaminergic neuronsBrain-derived neurotrophic factor(BDNF),a member of the neurotrophin family,also promotes survival of DA neurons(Krieglstein et al.,1996;Baquet et al.,2005)but
25、 via a different receptor tyrosine kinase,TrkB.The physiological role of BDNF in the ontogenetic(Kramer et al.,2007)or pathological(Baquet et al.,2005;Sun et al.,2005)death/survival of DA neurons is poorly understood.Death receptors and caspases but not mitochondria areactivated in the GDNF-or BDNF-
26、deprived dopaminergic neuronsClassically,apoptosis occurs via either death receptor or mitochondrial pathway(Danial and Korsmeyer,2004;Thorburn,2004;Riedl and Salvesen,2007).Ligated death receptors recruit and activate apical procaspase-8 via adapters as Fas-associated protein with death domain(FADD
27、)(Peter and Krammer,2003;Peter et al.,2007).In the mitochondrial pathway,activated proapoptotic proteins(e.g.,Bax)release proteins(including cytochrome c)from the mitochondria to the cytosol,leading to the assembly of an apoptosome and activation of apical caspase-9.Apical caspases cleave and activa
28、te executionary caspase-3,-6,and-7,which ultimately demolish the cell(Shacka and Roth,2006;Riedl and Salvesen,2007).Some caspases(e.g.,caspase-2)are activated via a different but poorly characterized mechanism(Troy et al.,2000;Baliga et al.,2004).Also,some nonclassical caspase-dependent apoptotic pa
29、thways have been described(Mehlen et al.,1998;Bredesen et al.,2006).Death receptors and caspases but not mitochondria areactivated in the GDNF-or BDNF-deprived dopaminergic neuronsWe recently showed that in the GDNF-deprived sympathetic neurons,caspase-2 and-7 are activated via a novel pathway witho
30、ut mitochondria and death receptors:Bax is not translocated to the mitochondria;cytochrome c is not released to the cytosol and caspase-9 and-3,but also caspase-8 and FADD are not involved(Yu et al.,2003).Here,we addressed the death pathways in GDNF-and BDNF-deprived DA neurons.In both cases,the neu
31、rons died via a nonclassical apoptotic pathway in which death receptors and caspases,but not mitochondria,were activated.Death receptors and caspases but not mitochondria areactivated in the GDNF-or BDNF-deprived dopaminergic neurons材料和方法 Cultures of 13-d-old mouse ventral mesencephalon and survival
32、 assays.Transfections.Immunocytochemistry.Reverse transcription-PCR.Immunoblot and coimmunoprecipitation.结 果 为假说提供证据！这篇文章的假说是什么？Here,we addressed the death pathways in GDNF-and BDNF-deprived DA neurons.In both cases,the neurons died via a nonclassical apoptotic pathway in which death receptors and c
33、aspases,but not mitochondria,were activated.结 果（研究内容）Embryonic dopaminergic neurons die in culture because of GDNF or BDNF deprivation Mitochondrial death pathway is not activated in GDNF-and BDNF-deprived dopaminergic neurons Caspases are required for the death of GDNF-or BDNF-deprived dopaminergic
34、 neurons The death receptor pathway is activated in GDNF-and BDNF-deprived dopaminergic neuronsDeath receptors and caspases but not mitochondria areactivated in the GDNF-or BDNF-deprived dopaminergic neurons讨论：从结果到结论的过程！具有以下几个主要特征：只对“结果”进行论述，而不应进行重述。论述其是怎样支持“结论”的。要能指出你的结果和解释与以前发表的著作相一致或不一致的地方。要论述你的研
35、究工作的理论含义以及实际应用的各种可能性。要能指出任何的例外情况或相互关系中有问题的地方，并且应明确提出尚未解决的问题及解决的方向。讨 论We have previously shown that GDNF-deprived sympathetic neurons activate caspases via a novel mitochondria-independent death pathway(Yu et al.,2003).Here we show that also the embryonic DA neurons do not activate mitochondrial deat
36、h pathway by deprivation of GDNF(but also BDNF):Bax is not translocated to the mitochondria and Bax inhibition does not block the death,cytochrome c is not released to the cytosol,and antiapoptotic mitochondrial protein Bcl-xL does not block the death.In the immunostaining experiments,we had to prev
37、ent cell death by caspase inhibition,because the changes in the localization of Bax and cytochrome c occur only briefly before death and were almost impossible to detect.The apoptotic mitochondrial changes are believed to occur without caspase involvement(Chang et al.,2002;Gogvadze et al.,2006),but
38、caspase-2 is reported to be activated upstream of mitochondria(Guo et al.,2002;Lassus et al.,2002;Robertson et al.,2004).We cannot exclude that caspase inhibition affected the movement of Bax and cytochrome c in our factor-deprived neurons.However,caspase-2 was not critical for the death of DA neuro
39、ns.Moreover,experiments with Ku70 or Bcl-xL were performed without caspase inhibitors.We therefore conclude that mitochondria were not activated in the neurotrophic factor-deprived DA neurons.Caspases were still absolutely required for the death of GDNF-and BDNF-deprived DA neurons.When compared wit
40、h the GDNF-deprived sympathetic neurons,the involved caspases were completely different:caspase-2 was critical for the death of GDNF-deprived sympathetic neurons but not GDNF-deprived DA neurons.Instead,the DA neurons died via caspase-9,-3,and-7,which were not essential in the sympathetic neurons.Ho
41、w caspase-9 is activated without cytosolic cytochrome c remains an open question.Caspase-9 is activated at the apoptosome by dimerization(Boatright et al.,2003;Pop et al.,2006),but it is also cleaved in the apoptotic cells,which enhances its catalytic activity(Bao and Shi,2007;Riedl and Salvesen,200
42、7).We speculate that caspase-8,activated at the death receptors,could cleave and activate caspase-9 in our neurons,as recently shown in other systems(McDonnell et al.,2003;Gyrd-Hansen et al.,2006).Indeed,blockage of caspase-8 prevented the death of the neurons,suggesting that caspase-9 is activated
43、downstream of caspase-8.Our attempts to visualize cleavage products of the caspases by Western blotting failed,most probably because of the small amount of the material available.Immunostaining of the cultures with antibodies to activated caspases also did not give consistent results in our hands.Th
44、us,further studies are required to understand caspase-9 activation in our model.Death receptors were activated in the GDNF-and BDNF-deprived DA neurons,because the death was significantly blocked by inhibition of caspase-8 or FADD,but also with overexpression of Fas inhibitor FAIML.Fas agonists and
45、antagonists as well as the PCR results strongly suggest the existence of functional Fas-like receptor on the surface of the DA neurons,and its activation by GDNF or BDNF deprivation.Most probably the Fas and FasL interact via neuritic contacts that are extensive in our dense cultures,as also suggest
46、ed for trophic factor-deprived motoneurons(Raoul et al.,1999;Ugolini et al.,2003;Raoul et al.,2006).Fas and FasL were constitutively present in the midbrain cultures,suggesting that an inhibitory system should prevent the unwanted activation of Fas.Indeed,we found that a neuron specific inhibitory p
47、rotein FAIML(Segura et al.,2007)was expressed in the midbrain cultures.FAIML interacts with Fas,both physically,as revealed by coimmunoprecipitation,and functionally,as revealed by transfection of DA neurons.Thus,the findings of Segura et al.(2007)were repeated in our model.It is tempting to specula
48、te that in the healthy DA neurons,Fas could perform some nonapoptotic functions(Peter et al.,2007)with its apoptotic activity blocked by FAIML,whereas FAIML could be degraded or removed from Fas by apoptotic stimulus such as neurotrophic factor deprivation.We found that de-ligation of Ret activates
49、different death pathways in sympathetic and DA neurons,whereas the same pathways were activated in the DA neurons by de-ligation of Ret and TrkB.We included BDNF for comparison to GDNF expecting different death pathways,because it was in the sympathetic neurons deprived of NGF(de-ligation of TrkA th
50、at is homologous to TrkB)(Yu et al.,2003).This was,however,not the case.The neurons can indeed sense the lack of neurotrophic support in many ways,depending on the neuronal type and/or the deprived factor.Thus,we show that the DA neurons have their own way to respond to neurotrophic factor deprivati
