4143
At the same time , the number of heparan sulphate anionic sites and the total anionic site surface ( number of anionic sites x mean anionic site surface ) in the lamina rara externa of the glomerular basement membrane was reduced by 19 % ( p < 0 . 021 ) and by 26 % ( p < 0 . 02 ) , respectively .
 heparan sulphate
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Disease, Chemical 
Text: {0} 
Answer:
 heparan sulphate