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J E Clausen

Publications and source records attributed to J E Clausen.

18 recordsLinked to original sources

Migration inhibitory effect of cell-free supernatants from PHA-activated cultures of human mononuclear leukocytes.

A two-step test for the demonstration of phytohaemagglutinin (PHA)-induced production of migration inhibitory factor (MIF) was investigated. In the first step, human purified mononuclear leukocytes were activated by incubation with PHA for 1 h. Then the cells were washed thoroughly and cultured for 1 to 4 days in TC medium without PHA. In the second step, the MIF-activity of the cell-free culture supernatants was tested on non-separated human leukocytes. The migration inhibition reaction was demonstrated by the agarose migration technique. The supernatants might have been contaminated by PHA, but it was shown that such contamination would be unable to cause any appreciable migration inhibition of the indicator leukocytes.

Cell Migration Inhibition↗

Migration inhibition of human leukocytes mixed with phytohemagglutinin-preincubated mononuclear leukocytes.

An in vitro test able to demonstrate phytohemagglutinin (PHA)-induced migration inhibition of human peripheral blood leukocytes was investigated. The migration inhibition was demonstrated by the agarose migration technique. Purified mononuclear leukocytes which had been incubated for 30 min with PHA, then washed and added to non-separated leukocytes induced migration inhibition of the mixed cell population. Since no PHA was added to the non-separated leukocytes, a direct PHA effect on polymorph migration was avoided. If the PHA-preincubated mononuclear leukocytes were heated at 56 degrees C for 30 min, their ability to cause migration inhibition was abolished. This suggests that the inhibition was caused by migration inhibitory factor (MIF) produced by the PHA-stimulated lymphocytes.

Cell Migration Inhibition↗