Simultaneous Determination of Residual Veterinary Drugs in Bovine, Porcine, and Chicken Muscle Using Liquid Chromatography Coupled with Electrospray Ionization Tandem Mass Spectrometry

A simple and rapid method using liquid chromatography coupled with electrospray ionization tandem mass spectrometry (LC/MS/MS) for the simultaneous determination of 130 veterinary drugs and their metabolites in bovine, porcine, and chicken muscle was developed. The drugs (1 to 10 ng/g, in muscle) were extracted from bovine, porcine, or chicken muscles with acetonitrile-methanol (95:5, v/v), and the extracts were delipidated with n-hexane saturated with acetonitrile. The extracts were evaporated, dissolved with methanol, analyzed by liquid chromatography with gradient elution on a C18 column, and determined by electrospray ionization tandem mass spectrometry. The detection limits ranged from 0.03 to 3 ng/g. The quantitation limits ranged from 0.1 to 10 ng/g. One hundred eleven, 122, and 123 drugs from bovine, porcine, and chicken muscle respectively showed recoveries between 70 and 110%.

2-Ethyl-3-methylmaleimide in Tokyo Bay sediments providing the first evidence for its formation from chlorophylls in the present photic and oxygenic zone

Tokyo Bay bottom sediments were analyzed for 2-ethyl-3-methylmaleimide, a degradation product of chlorophylls, which has been detected in ancient sediments. It was found in all sediments examined in concentrations of about 1 to 15 nmol/g- of dried sediment, and it was shown to be preserved for 100 years in the sediments. Its depth distribution agreed with that of the reported total organic carbon content of the sediments, reflecting a change in primary productivity. We concluded that this maleimide was produced under photic and oxygenic conditions in nature before the incorporation of photosynthesizing organisms into sediments.

A murine monoclonal antibody that recognizes an extracellular domain of the human c-erbB-2 protooncogene product

A murine IgM monoclonal antibody, designated SV2-61, was generated against human c-erbB-2 gene-transfected NIH-3T3 (SV11) cells. SV2-61 defined a 185-kDa molecule present on the surface of SV11 cells, another line of c-erbB-2 gene-transfected NIH-3T3 (A4-15) cells, and MKN-7 human gastric cancer cell line carrying an amplified human c-erbB-2 gene. The SV2-61-defined antigen was found to show protein kinase activity in vitro. The SV2-61 was reactive with human c-erbB-2 gene-transfected NIH-3T3 cell lines but not with transfectants carrying c-erbB-2 gene mutants which lack a coding region for the extracellular domain. It was reactive with a portion of human epithelial cell lines but not with native NIH-3T3, TGF-alpha-coding gene-, activated c-raf gene- or Ha-ras gene-transfected NIH-3T3 cells, or non-epithelial human cells. These results indicate that the SV2-61 is an antibody which recognizes an extracellular domain of the c-erbB-2 gene product, 185-kDa protein.