We analyzed the expression of class-I antigens in ex vivo human tumor cells by isoelectric focusing (IEF) the anti-class-I mAb W6/32 immunoprecipitates prepared from cell lysates. Out of 42 experiments, 27 were technically successful. The patient's blood lymphocytes were used as controls. In vitro exposure of the tumor cells to IFNy and TNFa elevated class-I antigen expression. In I I cases, defects in MHC-class-I-antigen expression were observed. In 2 cases the antigens were detected only in the cytokine-treated tumor samples, probably due to a defect in the association between b2m and class-I heavy chains. Selective changes in the expression of alleles were seen in 10 cases and might involve HLA A, 6 and C antigens. Alterations in class-I expression as compared with the lymphocytes were observed in 9 of I 3 cases in which the tumor cells were collected from metastases, and only in 2 of I 4 primary tumors.

AB TRACTThe duodenal perfusion technique was used to determine whether small peptides were more effective than free amino acids (FAA) for milk protein synthesis and to investigate the effects of infusing soyabean small peptides (SSP) or their FAA on the mammary amino acid (AA) metabolism of lactating goats. Six Saanen goats with silicon catheters implanted into their carotid artery and mammary veins were used in a Latin square design. Blood samples were collected from the carotid artery and mammary vein. The AA concentrations in the plasma, as well as mammary AA uptakes were monitored. The results showed that the concentrations of most essential amino acids (EAA) were significantly higher (P<0.05) in the FAA infusion treatment as compared with the SSP treatment, except for Val, Ile, and Met. The concentration of most of the non-essential amino acids (NEAA), measured after FAA infusion, was highest (P<0.05) when compared with the SSP treatment and the controls. The mammary uptake of most of EAA in the FAA infusion group was higher in comparison with the SSP infusion group. The mammary uptake to milk output ratios of EAA (except for Met) were low in the SSP treatment, compared with the FAA treatment. Significant increases in milk protein yield and milk protein content in the FAA infusion treatment were observed (P<0.05). In the SSP infusion treatment, milk yield and