Blood samples were analysed for pro- and anti-inflammatory cytokines : tumour-necrosis factor ( TNF ) - alpha , soluble TNF receptors ( sTNF-R ) -@ and -@ , interleukin ( IL ) -@ beta , IL-@ receptor antagonist ( IL-@Ra ) , IL-@ , and IL-@ as well as YKL-@ and the oxidative stress markers malondialdehyde ( MDA ) , ascorbic acid ( AA ) and dehydroascorbic acid ( DHA ) before and at @ , @ , @ and @ hours after LPS administration .