The in vitro tumoricidal activity of peritoneal macrophages harvested from C57BL mice and activiated by li posomes containing water-soluble muramyl dipeptides (MDP) was measured by ~(125)I.UdR release assay. The results demonstrated that liposomes containing MDP could effectively activiate macrophages to become tumoricidal. The percentage of pu(?)monarymetastasis and the average metastatic pulmonary colonies of mice with experimental tumor metastasis decreased after intravenous injection of MDP encapsulated in liposomes. These results suggested that systemic administration liposomes containing MDP whichinduced macrophage activiation might provide a useful immunot heray for tumor, especial1y for pulmonary mini metastasis.

Effects of vitamin A on antimetastatic activity of alveolar M 0 were studied. The results were as follows:1 . SD rats recieved vitamin A were killed and their alveolar M0 were harvested by lavage and cocultured with prelabelled B16 Melanoma cells for 48h in proportion of 20 : 1 , the average precentage of cytotoxity were 34.28%;2 . Zymosan-C3b rosette formation in SD rats treated with vitamin A was significantly increased. The average rosette forming rate was 43.00%. It was markdly higher than those of controls ( P

OBJECTIVE Inflammatory myofibroblastic tumor(IMT) is a rare lesion of unknown etiology which was first described in the lung. The clinical and pathologic characteristics,treatment, prognosis of IMT in head and neck were discussed. METHODS The clinical data of 4 cases of IMT were analyzed retrospectively. The specimens of the 4 cases were prepared for immunohistochemical staining and light microscopy. RESULTS The patients included 3 males and 1 female. Their age ranged from 32 to 58 years. The tumors located at the true vocal cord in 2 cases, at the nasal cavity and maxillary sinus in 1 case, at the maxillary sinus in 1 case. Histological examination was found that the tumors consisted of spindle cells,chronic inflammatory cells and myxoid background with delicate vasculature. Immunohistochemical staining demonstrated that the SMActin and Vimentin were expressed positively in the tumor. The patients were followed up for 9 to 21 months after operation. Three patients were alive with no evidence of diseases, one patients recurred at 4 months after operation and were alive with IMT. CONCLUSION IMT is a true neoplasm with a potential of local recurrence. The main treatment of IMT is to resect the lesions thoroughly.