Recognition of peptidyl epitopes by polymorphic epithelial mucin (PEM)-specific monoclonal antibodies.

Peptidyl epitope recognition by several murine monoclonal antibodies (MAbs E29, H23, HMFG-1, HMFG-2, MA5, MA6 and MA9) which react with the polymorphic epithelial mucins [PEM; epithelial membrane antigen (EMA)] was studied by using ten synthetic peptides representative of the 20 residue tandem repeat as test antigens. Antibody binding to 6-10 residue overlaps and to peptides having a common carboxy-terminus and staggered amino-termini (8-31 residues) was assessed by solid phase and competition ELISA techniques. From these analyses, all MAbs except MA9 were found to react predominantly with the carboxy-terminal half of the repeat motif. Polyclonal antibody responses in mice immunized with intact EMA/PEM-containing preparations also displayed significant reactivities against synthetic repeat peptide antigens and, conversely, synthetic peptides as carrier-conjugated immunogens induced antibodies recognizing intact antigens. These results are discussed vis-à-vis peptide conformation, the potential effects of O-glycosylation on secondary structure, and the possible effects of these parameters on immunogenicity and antigenicity.     

Intramitochondrial bodies in a human cell line carrying oncornavirus-like particles.

Electron-dense particles 80-100 nm in diameter were observed in electron micrographs of mitochondria in transformed mouse fibroblasts and in a human amnion cell line infected with supernatants of a human mammary carcinoma cell culture. Intramitochondrial particles were more numerous in the human cell cultures early after subculture. These particles were morphologically similar to those reported in mitochondria of Rous sarcoma virus-infected cells.     

Combined experimental and computational study of Al2O3 catalyzed transamidation of secondary amides with amines

Amides are the most extensively used substances in both synthetic organic and bioorganic chemistry. Unfortunately, the traditional synthesis of amides suffers from some important drawbacks, including low atom efficiency, high catalyst loading, separation of products from the reaction mixture and production of byproducts. Al₂O₃ is an amphoteric catalyst that activates the carbonyl carbon of the secondary amide group and helps the C–N cleavage of the reactant amide group by attacking the N–H hydrogen. By using the concepts of amphoteric properties of Al₂O₃, amides were synthesized from secondary amides and amines in the presence of triethylamine solvent. Several aliphatic and aromatic amines were used for the transamidation of N-methylbenzamide in the presence of the Al₂O₃ catalyst. Moreover, using the Gaussian09 software at the DFT level, HUMO, LUMO and the intrinsic reaction coordinates (IRCs) have also been calculated to find out the transition state of the reaction and energy. In this study, five successful compounds were synthesized by the transamidation of secondary amides with amines using a reusable Al₂O₃ catalyst. The catalyst was reused several times with no significant loss in its catalytic activity. The products were purified by recrystallization and column chromatography techniques. This catalytic method is effective for the simultaneous activation of the carbonyl group and N–H bond by using the Al₂O₃ catalyst.

Amides are the most extensively used substances in both synthetic organic and bioorganic chemistry.     

Perifornical Urocortin-3 mediates the link between stress-induced anxiety and energy homeostasis

In response to physiological or psychological challenges, the brain activates behavioral and neuroendocrine systems linked to both metabolic and emotional outputs designed to adapt to the demand. However, dysregulation of integration of these physiological responses to challenge can have severe psychological and physiological consequences, and inappropriate regulation, disproportional intensity, or chronic or irreversible activation of the stress response is linked to the etiology and pathophysiology of mood and metabolic disorders. Using a transgenic mouse model and lentiviral approach, we demonstrate the involvement of the hypothalamic neuropeptide Urocortin-3, a specific ligand for the type-2 corticotropin-releasing factor receptor, in modulating septal and hypothalamic nuclei responsible for anxiety-like behaviors and metabolic functions, respectively. These results position Urocortin-3 as a neuromodulator linking stress-induced anxiety and energy homeostasis and pave the way toward better understanding of the mechanisms that mediate the reciprocal relationships between stress, mood and metabolic disorders.     

In Vitro Production of Mouse Mammary Tumor Virus in a Mouse Mammary Tumor Ascites Line

An ascites line derived from a spontaneous mouse mammary carcinoma produces, on explantation and cultivation in vitro, large amounts of oncornavirus particles. The biochemical, biophysical, and electron microscopic characteristics of the virions are described. Molecular hybridization and immunological methods identify these virions as mouse mammary tumor virus.