title: Hyperbaric oxygen treatment reduced the lung injury of type II decompression sickness.
abstract: OBJECTIVE
  To detect the ultrastructural changes in rabbits with type II decompression sickness (DCS), and study the therapeutic effects of hyperbaric oxygen (HBO).
  
  
  METHODS
  Twenty-seven male New Zealand rabbits were randomly divided equally into the DCS group, HBO treatment group and control group. Experimental models of each group were prepared. Lung apex tissues were harvested to prepare paraffin- and EPON812-embedded tissues.
  
  
  RESULTS
  In the DCS group, macroscopic and histological examination revealed severe and rapid damage to lung tissue. Ultrastructural examination revealed exudation of red blood cells in the alveolar space. Type I alveolar epithelial cells exhibited retracted cell processes and swollen mitochondria, and type II cells showed highly swollen mitochondria and decrease in cytoplasmic lamellar bodies. Dilatation and congestion of capillary vessels were accompanied by swelling of endothelial cells and incomplete basement membrane. In the HBO treatment group, the findings were somewhat similar to those in the DCS group, but the extent of damage was lesser. Only a small amount of tiny bubbles could be seen in the blood vessels. Type I alveolar epithelia cells and endothelial cells of the capillaries illustrated slight shortening of cells, swollen cytoplasm and decreased cell processes. Type II alveolar epithelial cells showed slight swelling of the mitochondria, decreased vacuolar degeneration of lamellar bodies, and increase in the number of free ribosomes.
  
  
  CONCLUSIONS
  Our microscopic and ultrastructural findings confirm that the lung is an important organ affected by DCS. We also confirmed that HBO can alleviate DCS-induced pulmonary damage.
authors.affiliation: Department of Pathology, General Hospital of Jinan Military Command Ji'nan 250031, Shandong Province, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Geng
authors.affiliation: Department of Pathology, General Hospital of Jinan Military Command Ji'nan 250031, Shandong Province, China.
authors.forename: Luting
authors.initials: L
authors.lastname: Zhou
authors.affiliation: Department of Pathology, General Hospital of Jinan Military Command Ji'nan 250031, Shandong Province, China.
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Liu
authors.affiliation: Department of Pathology, General Hospital of Jinan Military Command Ji'nan 250031, Shandong Province, China.
authors.forename: Peifeng
authors.initials: P
authors.lastname: Li
mesh_terms: D055371:Acute Lung Injury / Q000473:pathology / Q000517:prevention & control*; D056809:Alveolar Epithelial Cells / Q000648:ultrastructure; D000818:Animals; D001522:Behavior, Animal; D015824:Blood-Air Barrier / Q000648:ultrastructure; D002196:Capillaries / Q000648:ultrastructure; D003665:Decompression Sickness / Q000473:pathology / Q000523:psychology / Q000628:therapy*; D004195:Disease Models, Animal; D006931:Hyperbaric Oxygenation; D008168:Lung / Q000098:blood supply / Q000648:ultrastructure*; D008297:Male; D008928:Mitochondria / Q000648:ultrastructure; D008933:Mitochondrial Swelling; D011817:Rabbits
keywords: Alveolar epithelial cells; decompression sickness; hyperbaric oxygen; lung; ultrastructure