tokens: Tumor necrosis factor alpha ( TNF-alpha ) mRNA production was analyzed by polymerase chain reaction amplification in monocytic U937 cells and in a chronically HIV infected U937 cell line ( U9-IIIB ) .
folded_tokens: tumor necrosis factor alpha ( tnf-alpha ) mrna production was analyzed by polymerase chain reaction amplification in monocytic u937 cells and in a chronically hiv infected u937 cell line ( u9-iiib ) .
labels: B-protein_molecule I-protein_molecule I-protein_molecule I-protein_molecule O B-protein_molecule O O O O O O B-other_name I-other_name I-other_name O O B-cell_line I-cell_line I-cell_line O O O B-cell_line I-cell_line I-cell_line I-cell_line I-cell_line I-cell_line O B-cell_line O O