Type II mixed cryoglobulinemia (MC) is an often progressive vasculitis characterized by circulating cold-precipitable proteins that usually consists of polyclonal IgG and monoclonal IgM kappa with rheumatoid factor (RF) activity. Its etiology is unknown, although recent evidence strongly suggests that hepatitis C virus (HCV) plays a major role. Plasmapheresis, corticosteroids, and cytotoxic dru...

The influence of interferon (IFN) on cellular proliferation, blast transformation, and differentiation was studied in lymph node cells from 17 patients with B-cell lymphomas, one patient with T-cell lymphoma, and eight patients with enlarged, non-malignant lymph nodes. The effects of IFN on lymph node cells were compared with effects on mononuclear blood cells from chronic lymphocytic leukemia ...

The nifN and -E gene products are involved in the synthesis of the iron-molybdenum cofactor of dinitrogenase, the enzyme responsible for the reduction of dinitrogen to ammonia. By using the in vitro iron-molybdenum cofactor biosynthesis assay, we have followed the purification of these gene products 450-fold to greater than 95% purity. An overall recovery of 20% was obtained with the purified p...

Ciliated protozoa have two functionally distinct nuclei, a micronucleus (MIC) and a macronucleus (MAC) [1]. These two nuclei are distinct in size, transcriptional activity, and division cycle control, proceeding with cycles of DNA replication and nuclear division at different times within the same cell [2, 3]. The structural basis generating functionally distinct nuclei remains unknown. Here, w...

A major nif cluster was detected in the strictly anaerobic, Gram-positive phototrophic bacterium Heliobacterium chlorum. The cluster consisted of 11 genes arranged within a 10 kb region in the order nifI1, nifI2, nifH, nifD, nifK, nifE, nifN, nifX, fdx, nifB and nifV. The phylogenetic position of Hbt. chlorum was the same in the NifH, NifD, NifK, NifE and NifN trees; Hbt. chlorum formed a clust...

Cytokines affecting mononuclear phagocytes were screened for activation of human macrophages to secrete H2O2 and kill toxoplasmas. In contrast to recombinant interferon-gamma (rIFN gamma), the following factors, tested in partially or highly purified form and over a wide range of concentrations, did not augment these functions: native interferon-alpha (nIFN alpha), rIFN alpha A, rIFN alpha D, r...

The iron-molybdenum cofactor (FeMo-co) of nitrogenase is a unique molybdenum-containing prosthetic group that has been proposed to form an integral part of the active site of dinitrogenase. In Klebsiella pneumoniae, at least six nif (nitrogen fixation) gene products are required for the biosynthesis of FeMo-co, including NIFB, NIFNE, NIFH, NIFQ, and NIFV. An in vitro system for the synthesis of...

background: leishmaniasis is a worldwide disease prevalent in tropical and sub- tropical countries. in the present study the immunogenicity of three human hla-dr1 restricted peptides derived from l. major gp63 protein was evaluated using fvb/n-dr1 transgenic mouse model. methods: the immunity generated by three mhc class ii – restricted peptides with the sequence of aarlvrlaaagaavt (aar), aaplv...

Molybdate- and ATP-dependent in vitro synthesis of the iron-molybdenum cofactor (FeMo-co) of nitrogenase requires the protein products of at least the nifB, nifN, and nifE genes. Extracts of FeMo-co-negative mutants of Klebsiella pneumoniae and Azotobacter vinelandii with lesions in different genes can be complemented for FeMo-co synthesis. Both K. pneumoniae and A. vinelandii dinitrogenase (co...