5975
Here , we describe how microsphere - bound A beta can stimulate microglial cells and be phagocytosed through a mechanism that is distinct from that of A beta removal and , thus , contribute to the clearance of A beta , even by defective microglial cells .
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Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
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