OxyFile #17

 TI    Studies on the Biological Effects of Ozone:
       Induction of Tumor Necrosis Factor on Human Leucocytes.

 DT    1991

 AU    Luana Paulesu, Enrico Luzzi and Velio Bocci

 SO    Lymphokine and Cytokine Research, Volume 10, Number 5

 AB    The effect of ozone as a probable inducer of tumor 
       necrosis factor (TNF) has been investigated on human blood 
       and on Ficoll-purified blood mononuclear cells (PBMC).  
       Samples were exposed at different ozone concentrations 
       ranging from 2.2 to 108 ug/ml and incubated at 37 degrees 
       Celsius in an 95% air-5% C02 atmosphere.  At predetermined 
       times, all cell supernatants were tested for TNF activity 
       and some PBMC cultures were examined for DNA synthesis.  
       We have shown that ozone concentration is critical in 
       terms of TNF production and of cell mitogenesis and that, 
       owing to the presence of erythrocytes, higher ozone 
       concentrations are required to be effective in blood than 
       in PBMC.  Because ozonization of blood is a procedure 
       followed in several European countries for the treatment 
       of viral diseases and tumors, the release of factors with 
       antiviral and immunomodulatory activities by leukocytes 
       may explain the mechanism of action of ozone and of