必修6Unit3AHealthyLife导学案阅读欣赏WhatWeStillDon'tKnowAboutAIDS
Inthe20yearssincethefirstcasesofAIDSaredetected,scientistssaytheyhavelearnedmoreaboutthisviraldiseasethananyother
YetPeterPiot,whodirectstheUnitedNationsAIDSprogram,andStefanoVellaofRome,presidentoftheInternationalAIDSSociety,andotherexpertssayreviewingunansweredquestionscouldproveusefulasameasureofprogressforAIDSandotherdiseases
Amongtheimportantbroaderscientificquestionsthatremain:1.WhatroutedoesHIVtakeafteritentersthebodytodestroytheimmunesystem
WhenHIVistransmittedsexually,thevirusmustcrossatissuebarriertoenterthebody
Howthathappensisstillunclear
Thevirusmightinvadedirectlyorbecarriedbyaseriesofdifferentkindsofcells
2.HowdoesHIVdestroytheimmunesystem
AlthoughHIVkillstheimmunecellssenttokillthevirus,thereiswidespreadvariation