We describe a region of human chromosome 8q24 involved in variant Burkitt's lymphoma translocations, and where an interstitial deletion occurs in an HTLV‐I+ ATL and three c‐myc amplicons terminate. ...The deletion in the ATL DNA begins within 1.3 kb of the cloned Burkitt's lymphoma translocation breakpoint and ends within 700 bases of the cloned human equivalent of the rat retroviral insertion site, mis‐1. In addition, three c‐myc amplicons terminate in this region and the end of one of these (the colon carcinoma COL0320) maps within 12 kb of the distal end of the ATL deletion. This region is probably approximately 300 kb downstream of c‐myc and the consistent occurrence of abnormalities in this region implies involvement in tumour aetiology in several different cell types.
Antigen-specific T cell activation requires two independent signalling events, one mediated through T cell receptor engagement by the antigen-presenting cell-expressed peptide/class II major ...histocompatibility complex, and the second through the cognate interactions of costimulatory molecules expressed on the T cell and antigen-presenting cell. There is evidence from in vitro and in vivo experimental systems suggesting that the CD28/B7 costimulatory pathway is crucial for induction of maximal T cell proliferation and T helper-B cell collaboration for IgG production. This pathway can be blocked by CTLA-4-Ig, a soluble form of CTLA-4 which binds with high avidity to the CD28 ligands, B7-1 and B7-2. Here, we show that CTLA-4-Ig treatment prevents clinical and histological manifestations of disease in a collagen-induced arthritis model of rheumatoid arthritis in the diabetes resistant BB/Wor rat, when therapy is initiated before immunization with bovine type II collagen (BIIC). Anti-BIIC antibody titers are reduced in CTLA-4-Ig-treated rats compared to diseased control animals. Histologically, joints from CTLA-4-Ig-treated animals show no histological abnormalities, in contrast to control antibody-treated animals, which show complete erosion of the articular cartilage and bone. Despite the efficacy of CTLA-4-Ig in preventing clinical and histological signs of arthritis and reducing antibody responses to BIIC, delayed type hypersensitivity responses to collagen 18 d or more after CTLA-4-Ig treatment ends are similar in CTLA-4-Ig-treated and untreated rats, suggesting that the prolonged disease suppression observed does not result from induction of T cell anergy.
THE discovery of two isoforms of the cyclooxygenase enzyme, COX-1 and COX-2, and the development of COX-2-specific inhibitors as anti-inflammatories and analgesics have offered great promise that the ...therapeutic benefits of NSAIDs could be optimized through inhibition of COX-2, while minimizing their adverse side effect profile associated with inhibition of COX-1. While COX-2 specific inhibitors have proven to be efficacious in a variety of inflammatory conditions, exposure of large numbers of patients to these drugs in postmarketing studies have uncovered potential safety concerns that raise questions about the benefit/ risk ratio of COX-2-specific NSAIDs compared to conventional NSAIDs. This article reviews the efficacy and safety profiles of COX-2-specific inhibitors, comparing them with conventional NSDAIDs.
Cytogenetic abnormalities involving chromosome 14 band q32 are consistently observed in human T-cell tumors. Patients with ataxia-telangiectasia (AT) are especially prone to development of these ...tumors, which frequently carry either inversion inv(14)(q11;q32) or translocation t(14;14) (q11;q32) chromosomes. We have previously shown that the cytogenetic breakpoints of one t(14;14)(q11;q32) chromosome and two inv(14)(q11;q32) chromosomes in T-cell tumors from AT and non-AT patients join the T-cell receptor α chain locus, at chromosome band 14q11, with a region(s) at 14q32 centromeric of the immunoglobulin heavy chain variable region (VH) gene IGHV. We now show that these two inv(14) breakpoints are linked by 2.1 kb of germ-line 14q32 DNA and that the three breakpoints define, by in situ hybridization analysis, a single locus at chromosome band 14q32.1 located about 15-20 million base pairs on the centromeric side of the IGH locus. Sequence analysis of the 14q32.1 breakpoint regions indicates that abnormal recombination does not universally result from mistaken V-D-J joining (D = diversity region; J = joining region). Therefore, we invoke a tumor selection model to describe the role of the 14q32.1 locus in tumor development.
Collagen-induced arthritis in the diabetes-resistant BB (DR BB)/Wor rat is a severe, aggressive disease initiated by immunization with heterologous native Type II collagen. Onset of clinical symptoms ...reproducibly occurs in 100% of animals between days 10 and 12 following collagen immunization. Hypertrophy of the synovial lining is the first histological manifestation of the early inflammatory arthritis. A mild inflammatory infiltrate in the synovium rapidly becomes a fibrovascular pannus eroding articular cartilage and subchondral bone. Beginning at the joint margins, an active synovitis is present. Light microscopy and immunohistochemical staining show the infiltrate to be comprised of mononuclear (lymphocytes, macrophages) and polymorphonuclear inflammatory cells. In addition, there is histological evidence for chronic inflammatory nodules and necrotizing vasculitis in connective tissue from diseased joints, both morphologic features associated with rheumatoid arthritis in humans. Subchondral bone erosion appears to be mediated largely by the resorptive action of activated osteoclasts. These histological parameters of disease progression in the DR BB/Wor rat are similar to human rheumatoid arthritis. The extensive degree of similarity in the pathology of DR BB/Wor rat collagen-induced arthritis and human rheumatoid arthritis supports the role of this model as an in vivo disease model for human rheumatoid arthritis.
T‐cell tumours are frequently found to carry an inversion of chromosome 14 (inv(14)) (q11;q32) or more rarely a chromosome 14 translocation t(14;14) with the same cytogenetic breakpoints (q11;q32). ...We have examined the molecular junctions of an inv(14) and a translocation t(14;14) using T‐cell receptor (TCR) alpha joining (J) region probes. Both of these chromosomal abnormalities have breakpoints within the TCR J alpha locus at 14q11 and both have breakpoints which are proximal (i.e. on the centromeric side) to the immunoglobulin heavy chain JH region at 14q32. The cloned segments corresponding to the junctions at 14q32 are not associated with obvious immunoglobulin‐like sequences. This contrasts to the previously described inv(14) in the cell line SUP‐T1 and places a potential cluster of chromosome 14 breakpoints downstream of the Ig JH locus. The possible role of the varying breakpoints in the development of these tumours is discussed.
The differential mechanism of action of vamorolone compared to traditional corticosteroid anti-inflammatory drugs is attributed to the loss of gene transcriptional activities associated with ...glucocorticoid response element binding and activation, potent antagonist activity for the mineralocorticoid receptor, superior membrane stabilization properties, and retention of the distinct NFκB inhibitory (anti-inflammatory) activities 3,5–7). Safety endpoints (linear growth, body mass index) are also compared with data from a 12-month trial of daily prednisone (0.75 mg/kg group) in similar-aged boys with DMD 17. Methods Ethics statement All studies had appropriate approvals by ethics committees or institutional review boards, as required by the 11 participating international academic clinical recruitment sites: (Duke University, Durham, NC, US; Alberta Children’s Hospital, Calgary, AB, Canada; Nemours Children’s Hospital, Orlando, FL, US; John Walton Muscular Dystrophy Research Centre, Newcastle University, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK; Queen Silvia Children’s Hospital, Gothenburg, Sweden; Schneider Children’s Medical Center, Tel Aviv University, Petah Tikvah, Israel; Royal Children’s Hospital and Murdoch Children’s Research Institute, Melbourne, VIC, Australia; The Children’s Hospital at Westmead, Sydney, NSW, Australia; University of Texas Southwestern Medical Center, Dallas, TX, US; Ann & Robert H. Lurie Children’s Hospital of Chicago, Chicago, IL, US; University of California Davis, Davis, CA, US). ...the total duration of corticosteroid treatment was longer than 18 months for most participants.
Reduced galactosylation of immunoglobulin G (IgG) is well documented in rheumatoid arthritis (RA), but the reason for this defect is still unknown. There is some evidence supporting a defect in the ...biosynthetic pathway, and a reduction in the level of β‐1,4‐galactosyltransferase (β‐1,4‐GalTase) enzyme activity. Since glycosyltransferases are, in general, regulated at the level of transcription, we have measured the level of β‐1,4‐GalTase gene expression in B cells from patients with RA and normal control individuals. We found no significant difference in mRNA levels for the transferase in these two groups (P > 0.7). MRL/Mp‐lpr/lpr (MRL‐lpr) mice develop a spontaneous arthritis with increased levels of agalactosyl IgG (G0). In spite of a significant reduction in the level of β‐1,4‐GalTase mRNA in total spleen lymphocytes from MRL‐lpr mice compared with the congenic MRL/Mp‐+/+ (MRL‐+/+) mice and with CBA/Ca mice, we found comparable levels of the β‐1,4‐GalTase mRNA in purified B cells from both spleen and lymph nodes of the three strains. Amongst the lymphoid compartments examined, the spleen and peripheral blood were found to be the major contributors of G0 in MRL‐lpr mice. These data indicate that in neither human RA, nor in an animal model of this disease, is reduced IgG galactosylation caused by impaired expression of the β‐1,4‐GalTase gene in B lymphocytes. Furthermore, splenic B cells, which have normal levels of β‐1,4‐GalTase mRNA, appear to be a major source of G0 in MRL‐lpr mice.
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