Binding of chemical derivatives of Phaseolus vulgaris phytohemagglutinin to pig spleen lymphocytes.

The mitogenic activity of Phaseolus vulgaris phytohemagglutinin (PHA) and its acetyl, citraconyl, glycinyl, homoarginyl, N-bromosuccinimide, and nitro derivatives has been assayed using pig spleen lymphocytes. Nitrated and N-bromosuccinimide-treated PHA were not mitogenic. Whereas the mitogenicity of acetyl PHA was impaired, the other derivatives were as active as untreated lectin.

Impairment by covalent modification of the ability of Phaseolus vulgaris phytohemagglutinin to stimulate cultured human lymphocytes: a comparison of different forms of covalent modification.

Phytohemagglutinin (PHA) isolated from Phaseolus vulgaris has been modified by treatment with various chemical reagents and the modified proteins have been tested for their ability to stimulate peripheral lymphocytes from two healthy human donors, in vitro. Reaction of PHA with citraconic anhydride, S-methyl isothiourea, or 2-hydroxy-5-nitrobenzyl bromide produced derivatives which retained the ability to stimulate lymphocytes, at low concentrations. Acylation of the lectin with acetic anhydride or masking of the carboxyl side chains by reaction with glycinamide-carbodiimide impaired stimulation.

Studies on poison ivy. In vitro lymphocyte transformation by urushiol-protein conjugates.

The isolation and purification of poison ivy urushiol is described. The preparation of urushiol-ski protein and urushiol human serum albumin is also described. Lymphocytes from eleven donor naturally sensitized to poison ivy and from four non-sensitive individuals have been cultured for 5 days in the presence of urushiol-carrier conjugates.

Toxic effect of alantolactone and dihydroalantolactone in in vitro cultures of leukocytes.

Alantolactone, an allergenic sesquiterpene lactone, is toxic to leukocytes in in vitro cultures. Cell (1 X 10(6) cells/ml of culture) stimulation by pokeweed mitogen (PWM) decreases with increasing amounts of terpene. A concentration of 1 mug/ml of culture decreases stimulation by 50%.

The binding of phytohemagglutinin M to rat spleen lymphocytes. Quantitative studies.

Phytohemagglutinin M (PHAM) has been purified from the commercial mixture of proteins produced by Phaseolus vulgaris, using a Sepharose-thyroglobulin column. The protein gave one band on gel electrophoresis and two bands on SDS-gel electrophoresis (mol. wt.

Metabolic behaviour of water-soluble fluorescent whitening agents in the rat and bean plant.

The behaviour of three representative water-soluble fluorescent whitening agents (FWAs) was studied in rats and bean plants using 14C-labelled compounds. Following oral doses of 5 mg/kg of each of the FWAs to rats, rapid and complete excretion of radioactive material was observed, with an excretion half life ranging from 7-13 hours. Faeces were practically the only route of excretion, indicating, in combination with the short half life times, that no significant amounts of whitener were absorbed from the digestive tract.