【医学课件】肠道病毒与轮状病毒

,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,Polio virus,Nervous system,: Polio is a virus that infects the nervous system of humans (only),Paralysis,: It can cause temporary or permanent paralysis or death,Vaccine,:There is a vaccine for polio,Eradicate,:The World Health Organization plans to eradicate polio in the next decade,Continue,: Polio outbreaks continue to occur in areas in which many are not vaccinated,Polio virusNervous system: Pol,1,Since vaccine has become widespread in the United States, cases of polio are rare.,However, polio remains a problem in many parts of the world.,Since vaccine has become wides,2,【医学课件】肠道病毒与轮状病毒,3,肠道病毒,肠道病毒,4,Poliovirus infects human cells by binding to an,immunoglobulin-like,receptor,CD155, (also known as the,poliovirus receptor,(PVR) on the cell surface,Poliovirus is a positive stranded,RNA virus,. Thus the genome enclosed within the viral particle can be used as,messenger RNA,and immediately,translated,by the host cell.,Poliovirus infects human cells,5,Poliovirus uses two key mechanisms to evade the,immune system,. First, it is capable of surviving the highly,acidic,conditions of the,gastrointestinal tract, allowing the virus to infect the host and spread throughout the body via the,lymphatic system,.,Second, because it can replicate very quickly, the virus overwhelms the host organs before an immune response can be mounted.,5,Immune system avoidance,Poliovirus uses two key mechan,6,学习要求,掌握,1、脊髓灰质炎病毒的致病性,2、特异性预防（剂型）,自学柯萨奇病毒,3、熟悉脊髓灰质炎病毒抵抗力、感染类型,自学埃可病毒,学习要求掌握自学柯萨奇病毒3、熟悉脊髓灰质炎病毒抵抗力、感染,7,polio virus,polio virus,8,【医学课件】肠道病毒与轮状病毒,9,3-D image of poliovirus,3-D image of poliovirus,10,VP1,VP2,VP3,5-fold Axis,3-fold Axis,2-fold Axis,VP15-fold Axis3-fold Axis2-fol,11,For decades, no one knew what poliovirus looked like, since viruses cannot be seen under a microscope. In 1985, a team led by James Hogle of Harvard Medical School obtained high-resolution, 3D images of poliovirus, and today, the newly formed Childrens Hospital Boston - Harvard Medical School structural biology unit is heir to the Enders tradition.,For decades, no one knew what,12,Led by Stephen Harrison, this group is using a variety of sophisticated tools like X-ray crystallography and molecular electron microscopy to obtain detailed, dynamic, 3D views - accurate down to the atom - of how viruses move, transfer information and reconfigure themselves to attack their victims. These images are shedding light on many of todays viral scourges, such as HIV, dengue and rotavirus, and providing new leads for treatment and vaccine development.,Led by Stephen Harrison, this,13,Polio virus,Polio virus,14,An ancient Egyptian stele, portraying a prince with a withered leg - probably polio. WHO/GPEI,An ancient Egyptian stele, por,15,【医学课件】肠道病毒与轮状病毒,16,【医学课件】肠道病毒与轮状病毒,17,【医学课件】肠道病毒与轮状病毒,18,Researchers Glimpse Polio Virus as it Enters Host Cell Contact:,The image on the left shows a naked polio virus. The polio virus on the right is studded with 60 twig-like structures, the receptors.,See for a moment,Small thin stem on a tree,3-,D structures,Researchers Glimpse Polio Viru,19,【医学课件】肠道病毒与轮状病毒,20,The polio virus lives in the throat and intestinal tract of infected persons.,The virus enters the body through the mouth, usually from hands contaminated with the stool of an infected person. Objects, such as eating utensils, can also spread the virus.,Food and water are not thought to play a major role in the spread of polio.,The polio virus lives in the t,21,WHO,Polio cases have decreased by 99.8% since 1988, from an estimated 350 000 cases to 483 in 2001*. The reduction is the result of the global effort to eradicate the disease.,WHOPolio cases have decreased,22,Areas with high-intensity transmission,Together, these countries accounted for more than 85% of the new polio caseload in 2001. They are characterized by having areas with large populations and low routine immunization coverage, sub-optimal sanitation and relatively wide geographical distribution of the wild poliovirus. These countries are:,India,Pakistan/Afghanistan,Nigeria/Niger,Areas with high-intensity tran,23,病毒抵抗力,在污水和粪便中可活数月,食品中可保存数周,不易被胃酸或胆汁灭活,对氧化剂敏感,56,。,C,30min,被灭活,病毒抵抗力在污水和粪便中可活数月,24,致病性,传染源：病人或无症状携带者,传染方式：粪-口途径,致病机理,致病性传染源：病人或无症状携带者,25,二、致病性,病毒,咽部、肠壁淋巴组织,入血流,第1次病毒血症,入全身淋巴组织,再次入血流,病毒入,脊髓前角运动神经细胞,：,（脊髓型）,延髓和脑干：延髓型 大脑运动皮质区：脑炎型,第2次病毒血症,二、致病性病毒咽部、肠壁淋巴组织入血流第1次病毒血症入全身淋,26,感染类型,人群中绝大多数为,隐性感染,或轻型感染,显性感染,引起麻痹者仅为显性感染的0.1%-1%,顿挫感染,感染类型人群中绝大多数为隐性感染或轻型感染,27,免疫性,SIgA：,清除肠道内病毒，阻止病毒入血,IgM,IgG:,阻断血流中病毒向中枢神经系统扩散,感染后获得对同型病毒较牢固的免疫力,免疫性SIgA：清除肠道内病毒，阻止病毒入血,28,Symptoms,Not everyone will experience all the symptoms, which vary according to the type of polio one has. In,mild polio,the symptoms are:,Headache,Nausea/vomiting,General discomfort or slight fever for up to three days.,SymptomsNot everyone will exp,29,In,non-paralytic polio, the symptoms are similar to mild polio with the addition of:,Moderate fever,Stiff neck and back,Fatigue,Muscle pain,In non-paralytic polio, the sy,30,Individuals with,paralytic polio,will experience:,Tremors,Muscle weakness,Fever,Stiffness,Constipation,Muscle pain and spasms,Difficulty swallowing,Individuals with paralytic pol,31,预防,口服,脊髓灰质炎减毒活疫苗糖丸(1957年发明）,Oral vaccination with live vaccine,Vaccination programs have,eradicated it from the,Western world and promise,to eliminate it globally,Dr Alber Sabin,预防口服脊髓灰质炎减毒活疫苗糖丸(1957年发明） Oral,32,【医学课件】肠道病毒与轮状病毒,33,疫苗使用的效果,疫苗使用的效果,34,【医学课件】肠道病毒与轮状病毒,35,Scientists,have built the virus,that causes polio from scratch in the lab, using nothing more than,genetic sequence,information from public databases and readily available technology.,The fact proves that even if all the polio virus in the world were destroyed, it would be easily possible to,resurrect,the crippling disease, says Aniko Paul at the State University of New York at Stony Brook, one of the researchers conducting the study.,新进展,Date: Thu, 11 Jul 2002,Bring back into use,Scientists have built the v,36,Journal reference: Science (DOI: 10.1126/science.1072266,),The result has major implications for,vaccination programs,that have nearly rid the world of polio. I think it means youre probably not going to be able to stop vaccinating people even after you eradicate the virus, says Diane Griffin of the Johns Hopkins Bloomberg School of Public Health.,Journal reference: Science (DO,37,Paul believes the synthesis method could be applied to,other viral diseases,.We feel this could be used for,ebola, smallpox, just about anything, she says.,This raises the worrying possibility that,bioterrorists,could use a similar approach to create devastating diseases without having to gain access to protect viral stocks.,Paul believes the synthesis,38,paralysis,electron microscopy and X-ray,crystallography.,Summary of polio virus,vaccination programs have eradicated it from the Western world and promise to eliminate it globally,Surprisingly little is known about how poliovirus enters the cells of the intestines, let alone how it makes its way to the nervous system where it can damage motor neurons and cause paralysis,paralysiselectron microscopy a,39,轮状病毒,轮状病毒,40,形态,核心为dsRNA，外有双层衣壳，内外两层呈放射状排列,形态核心为dsRNA，外有双层衣壳，内外两层呈放射状排列,41,轮状病毒,分组：,A,、,B,、,C,组：可引起人、动物腹泻， 最常见,A,组(,有称为小儿轮状病毒）,D-G,组,：仅引起动物腹泻,A,组抵抗力： 耐乙醚、弱酸 室温中传染性可保持7个月 -20,。,C,长期保存,轮状病毒分组：,42,A组轮状病毒,所致疾病： 婴幼儿尤其秋冬季急性胃肠炎,传播途径：粪-口途径,机理：病毒在十二指肠粘膜细胞中增殖 影响肠道对水、盐的正常吸收 腹泻（粪便绿或白色），常伴发热，严重者可出现脱水或酸中毒,A组轮状病毒所致疾病：,43,B组轮状病毒,引起成人腹泻,我国1982年首先发现,B组轮状病毒引起成人腹泻,44,特异性预防,尚无疫苗接种,特异性预防尚无疫苗接种,45,思考题,为什么预防脊髓灰质炎的预防针选用口服制剂？,思考题为什么预防脊髓灰质炎的预防针选用口服制剂？,46,