6152
To gain further insight into the pathogenesis of the adult respiratory distress syndrome ( ARDS ) , the authors studied possible relationships among the activation status of circulating polymorphonuclear neutrophils ( PMN ) , cytokine levels , and the severity of lung injury in 31 patients : 15 with ARDS , 9 with severe pneumonia uncomplicated by ARDS , and 7 mechanically ventilated patients with neither ARDS nor pneumonia .
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Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: GENE 
Text: {0} 
Answer:
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