Contact sensitivity in mice measured with thymidine labeled lymphocytes

An ear assay was used to detect delayed responses in mice. Animals were sensitized and subsequently injected with 3H thyminedeoxyryribose to label antigen sensitive cells. Each animal was given a control and a test ear challenge and the respective responses were assessed by scintillation counting of 3H in cells which had accumulated at the reaction site. Delayed responses were consistently observed in animals sensitized to dinitrochlorobenzene (DNCB) but not in animals sensitized to sheep red blood cells. Reactivity to DNCB was minimal in tolerant animals and animals sensitized to the control agent. Both peritoneal exudate and spleen cells of antigen-sensitized animals were found to contain more label than cells from non-sensitized animals.

The effects of feeding peptide-precipitating lignosulphonic acids in various concentrations to growing pigs

It is shown that lignosulphonic acids, at a concentration of 13 % in conventional feed given to growing pigs, lead to a marked reduction in the weight gain.

When given 3 % and 6 % lignosulphonic acids in the feed, no effects on the weight gain were observed as compared to the controls.

The weight gain reduction caused by lignosulphonic acids at high levels in the feed is discussed in relation to the inhibitory effects of these acids on a number of biological systems which have been studied previously.