2450
Matrix metalloproteinase activity , determined using a quenched fluorescence substrate assay , increased during early healing ( 3 - 8 weeks ) compared to controls , and then decreased between 24 and 36 weeks after surgery ( p less than 0 . 05 until 24 weeks , Mann - Whitney U - test ) .
 None
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Anatomy 
Text: {0} 
Answer:
 None