A simple and accurate method is described for the quantitative determination of acid phosphatase in macrophage, spleen and thymus homogenates, utilizing sodium ?-naphthyl acid phosphate as substrate, and the monocoupler Fast Red B Salt as the color developer to measure ?-naphthol released from the substrate by enzymatic hydrolysis reaction.The color product is a deep blue azo dye,stable for at least 1h in alkaline condition. The method is sensitive enough for assay of enzyme activity of macrophages at concentration low as 1?10~6 cell/ml. The acid phosphatase activity of macrophages from mice treated with thioglycollate elevated significantly. Some factors affecting assay are discussed. Above all, the color developer solution should be made freshly and the peritoneal macrophages collected from mice should be broken in an ultrasonic breaker before assay.

Among the 7 artificial paraoxon antigens studied, we found that paraoxon-tetanus toxoid has the best immunologic effect. All the 14 immunized rabbits with paraoxon-tetanus toxoid survived after a challenge of 1LD of paraoxon injected intramuscularly. The effective prophylactic period was 1 month. There were more than 10 units of antitetanus antitoxin in 1 ml antiserum of the immunized rabbit.

The stimulate effects of synthetical endogenous peptides, tuftsin (Tuf) and thymopentin(TP5), on phagocytic function were studied. After subcutaneous administration (sc) of Tuf, thelysozyme content in both M? and sera, and the acid phosphatase activity in M?, were increasedin a dose-dependent manner. The peak time of serum lysozme level following a sigle sc injectionof Tuf was about on the 6th day. The elevation of lysozyme in sera was delayed and enhancedstrongly by Freund incomplete adjuvant (FIA). In cylcophosphamide (Cy) treated mice,TP5further increased both lysozyme content amd acid phosphatase activity in M?activated byCy, and recovered the lysozyme level in spleen inhibited by cy. The results suggested thatTP5could not only activate the funceion of M?, but recover the number of M?decreased by im-mumoimhibitant.

Tetrodotoxin(TTX) was coupled to Tachypleus tridentatus hemocyanin (TTH) chemically to form an artificial antigen.Balb/c mice were immunized with TTX TTH. The immunologic effect of different immunization schedules [14～20d for longer interval (group L) and 7～10d for shorter interval (group S)] of experimental anti TTX vaccine was compared. The quality of antisera and effect of vaccine on TTX poisoning were detected. The antibody quality of serum was increased more quickly in group S than that in group L after immunization. The average survival rates were 99 3% and 92 9%, respectively ( P