title: Acute respiratory distress syndrome induced by a swine 2009 H1N1 variant in mice.
abstract: BACKGROUND
  Acute respiratory distress syndrome (ARDS) induced by pandemic 2009 H1N1 influenza virus has been widely reported and was considered the main cause of death in critically ill patients with 2009 H1N1 infection. However, no animal model has been developed for ARDS caused by infection with 2009 H1N1 virus. Here, we present a mouse model of ARDS induced by 2009 H1N1 virus.
  
  
  RESULTS
  Mice were inoculated with A/swine/Shandong/731/2009 (SD/09), which was a 2009 H1N1 influenza variant with a G222D mutation in the hemagglutinin. Clinical symptoms were recorded every day. Lung injury was assessed by lung water content and histopathological observation. Arterial blood gas, leukocyte count in the bronchial alveolar lavage fluid and blood, virus titers, and cytokine levels in the lung were measured at various times post-inoculation. Mice infected with SD/09 virus showed typical ARDS symptoms characterized by 60% lethality on days 8-10 post-inoculation, highly edematous lungs, inflammatory cellular infiltration, alveolar and interstitial edema, lung hemorrhage, progressive and severe hypoxemia, and elevated levels of proinflammatory cytokines and chemokines.
  
  
  CONCLUSIONS
  These results suggested that we successfully established an ARDS mouse model induced by a virulent 2009 H1N1 variant without previous adaptation, which may be of benefit for evaluating the pathogenesis or therapy of human ARDS caused by 2009 H1N1 virus.
authors.affiliation: Key Laboratory of Animal Epidemiology and Zoonosis, College of Veterinary Medicine, China Agricultural University, Ministry of Agriculture, Beijing, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.forename: Honglei
authors.initials: H
authors.lastname: Sun
authors.forename: Lihong
authors.initials: L
authors.lastname: Fan
authors.forename: Yuan
authors.initials: Y
authors.lastname: Ma
authors.forename: Yipeng
authors.initials: Y
authors.lastname: Sun
authors.forename: Juan
authors.initials: J
authors.lastname: Pu
authors.forename: Jun
authors.initials: J
authors.lastname: Yang
authors.forename: Jian
authors.initials: J
authors.lastname: Qiao
authors.forename: Guangpeng
authors.initials: G
authors.lastname: Ma
authors.forename: Jinhua
authors.initials: J
authors.lastname: Liu
mesh_terms: D000818:Animals; D001784:Blood Gas Analysis; D001992:Bronchoalveolar Lavage Fluid / Q000821:virology; D016207:Cytokines / Q000096:biosynthesis; D004195:Disease Models, Animal; D004487:Edema / Q000821:virology; D005260:Female; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000235:genetics; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000235:genetics* / Q000472:pathogenicity* / Q000502:physiology; D007700:Kinetics; D007958:Leukocyte Count; D008168:Lung / Q000821:virology; D051379:Mice; D009154:Mutation; D012128:Respiratory Distress Syndrome / Q000097:blood / Q000378:metabolism / Q000473:pathology / Q000821:virology*; D013552:Swine / Q000821:virology*; D014779:Virus Replication
chemical_list: D016207:Cytokines; D019267:Hemagglutinin Glycoproteins, Influenza Virus