Mutations in immunoglobulin V-genes can be due to gene multiplication, allelic variations, mutations induced by antigens or somatic mutations, etc., and various combinations of these. Since the number of different mouse lambda light V-gene nucleotide sequences is relatively small, a pairwise comparison between these sequences can provide a rough idea as to the contributions of the above mechani...

apoptosis, or active cell death, is a specific mode of cell death, which is characterized by morphological changes such as chromatin condensation, fragmentation of the nucleus, cytoplasmic retraction and appearance of apoptotic bodies' containing apparently intact organelles. apoptosis occurs in physiological conditions as a regulatory mechanism of tissue growth, where cell proliferation is bal...

by immunizing mice with killed whole bacterial cells of brucella abortus s (99), a panel of six hybridomas producing monoclonal antibodies (mab) specific for the surface antigens of this bacterium were produced. elisa was used to screen the hybridoma supernatants. immunoblots of the cell extract indicated that three mab were specific for s-lps (ba-1, ba-2, ba-3) and three others were reactive w...

psychological or behavioral interventions that attenuate the effects of stress may be useful in promoting immunocompetence and delaying hiv disease progression and cd4 count level. mindfulness-based stress reduction (mbsr) is a behavioral intervention that has as its foundation the practice of insight-oriented (or mindfulness) meditation. in this study, we examined the effects of mbsr upon psyc...

background and objective: the outcome of hepatitis b virus (hbv) infection may be influenced by host factors like human leukocyte antigen (hla). we have investigated hla-a and drb1 alleles in patients with persistent hepatitis b infection compared to subjects who had spontaneously recovered from hbv infection. to complete the findings of this study we performed another survey in certain hla all...

extramedullary plasmacytoma is a rare neoplasm characterized by monoclonal proliferation of plasma cells. most lesions occur in the head and neck, primarily in the upper aerodigestive tract. the nasal cavity and nasal septum are the most common sites of occurrence. in this report, three patients admitted in our clinic with history of nasal obstruction and/or epistaxis. patients were diagnosed w...

In systemic lupus erythematosus (SLE) it has been hypothesized that self-reactive B cells arise from virgin B cells that express low-affinity, nonpathogenic germline V genes that are cross-reactive for self and microbial antigens, which convert to high-affinity autoantibodies via somatic hypermutation. The aim of the present study was to determine whether the VH family repertoire and pattern of...

Germinal centers (GCs) are the primary site at which clonal expansion and affinity maturation of B cells occur. B cells encounter antigen and receive T cell help in the GC light zone (LZ) and then migrate to the dark zone where they proliferate and undergo somatic mutation before cycling back to the LZ for further rounds of selection. Tolerance to autoantigens is frequently lost de novo as GC B...