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The inactivation of Listeria monocytogenes Scott A and Salmonella typhimurium in synthetic egg washwater was studied under varying conditions of temperature (38°C to 46°C), egg solids (0%, 2%), pH (9·5 to 10·5) and chlorine concentration (0 to 10 µg ml^-1 [ppm]) using a full factorial design. Survival was measured as the logarithm of the time required for a 4-log reduction in viable counts. Both pathogens were significantly affected by temperature and the presence of egg, while the survival of S. typhimurium was significantly reduced by pH and chlorine alone. Both pathogens were affected by second order interactions involving egg and either pH or chlorine. Egg was the most significant factor, reducing the survival of L. monocytogenes while promoting the survival of S. typhimurium. Two linear equations were derived to describe the decrease in survival of L. monocytogenes and S. typhimurium as a function of the 4 factors. These equations were used to estimate conditions which would reduce the time for a 4-log reduction in viable counts to <30 min. In the absence of egg solids, chlorine (20 µg ml^-1) can be used to control L. monocytogenes and S. typhimurium using moderate temperature (42°C) and pH (10·5). When egg is present in wash water, increased temperature (47·4°C) and pH (10·8) are required. Copyright 1994, 1999 Academic Press

The NF-kappa B-p50 polypeptide, a member of the Rel family of transcription factors, was produced as a fusion protein containing amino-terminal peptide additions that facilitate purification and detection with a monoclonal antibody and specific radiolabeling by phosphorylation in vitro. The 32P-labeled NK-kappa B-p50 fusion polypeptide was used as the probe in Western blotting experiments and in screenings of a bacteriophage expression library to isolate cDNAs encoding interacting protein domains. As expected, cDNAs encoding proteins of the Rel family were identified. Surprisingly, the 32P-labeled NF-kappa B protein also specifically bound to proteins encoded by cDNAs for the human NF-IL6 transcription factor. The NF-kappa B-p50 and NF-IL6 proteins directly interact, and the Rel homology domain and leucine-zipper motif, respectively, are important for this interaction. Since induction of the NF-kappa B and NF-IL6 factors are important events in immune and acute-phase responses, this interaction could permit coregulation of genes.

Murine Ly-6-encoded molecules play an important role in the antigen-independent activation of lymphocytes. We have described the cloning of a cDNA encoding the protein component of an Ly-6 molecule. Hybridization studies indicated that this cDNA identified multiple DNA fragments on Southern blots. The banding pattern exhibits a restriction fragment length polymorphism from mice bearing either the Ly-6a or the Ly-6b allele. We have employed three independent chromosomal mapping techniques, somatic cell hybrids, in situ hybridization, and strain distribution pattern analysis of the restriction fragment length polymorphism of DNA from recombinant inbred lines, to ascertain the chromosomal origins of these bands. We report that all members of the Ly-6 multigene family are tightly linked on chromosome 15 and have been regionalized by in situ hybridization analysis to band 15E on the distal portion of this chromosome. Linkage analysis has indicated that the Ly-6 genes are located within 1 map unit of Env-54 (a retroviral envelope restriction fragment length polymorphism probe), 3 map units from ins-1, (insulin-related gene), and 4 map units from the protooncogene c-sis. The possible involvement of the Ly-6 lymphocyte activation and differentiation antigen genes in chromosome 15-related lymphoid malignancies is discussed.

A cDNA from a B-cell library was previously isolated that encodes a sequence-specific DNA-binding protein with affinities for related sites in a class I major histocompatibility complex (MHC) and kappa immunoglobulin gene enhancers. We report here approximately 6.5 kilobases of sequence of the MBP-1 (MHC enhancer binding protein 1) cDNA. MBP-1 protein has a molecular weight predicted to be greater than 200,000. A DNA-binding domain with high affinity for the MHC enhancer sequence TGGGGATTCCCCA was localized to an 118-amino-acid protein fragment containing two zinc fingers of the class Cys2-X12-His2. Analysis of expression of MBP-1 mRNA revealed relatively high expression in HeLa cells and in a human retinal cell line, with lower levels in Jurkat T cells and in two B-cell lines. Interestingly, expression of MBP-1 mRNA was inducible by mitogen and phorbol ester treatment of Jurkat T cells and by serum treatment of confluent serum-deprived human fibroblasts.