Kruskal's Tree Theorem for Acyclic Term Graphs

In this paper we study termination of term graph rewriting, where we restrict our attention to acyclic term graphs. Motivated by earlier work by Plump we aim at a definition of the notion of simplification order for acyclic term graphs. For this we adapt the homeomorphic embedding relation to term graphs. In contrast to earlier extensions, our notion is inspired by morphisms. Based on this, we establish a variant of Kruskal's Tree Theorem formulated for acyclic term graphs. In proof, we rely on the new notion of embedding and follow Nash-Williams' minimal bad sequence argument. Finally, we propose a variant of the lexicographic path order for acyclic term graphs.Comment: In Proceedings TERMGRAPH 2016, arXiv:1609.0301

The effects of Kv1.3 and IKCa1 channel inhibition on cytokine production and calcium influx of T lymphocytes in rheumatoid arthritis and ankylosing spondylitis

Kv1.3 and IKCa1 lymphocyte potassium channels have been implicated as important targets of selective immunomodulation. We compared the alterations in cytokine production upon selective inhibition of Kv1.3 or IKCa1 channels (by MGTX and TRAM, respectively) in healthy donors (HD), RA and AS patients. We also determined calcium influx kinetics and its sensitivity to Kv1.3 and IKCa1 channel inhibition following PHA activation in CD4, Th1, Th2 and CD8 cells as well as monocytes. The application of TRAM resulted in a lower production of TNF-a and IL1-RA in all three study groups. Inhibition by TRAM had contrary effects on the production of IL-1b and IL-5: While their production was increased by PBMCs of RA patients, this effect was not observed in HD and AS PBMCs. While treatment with MGTX resulted in a similar decrease in calcium influx in the CD4 and Th2 subsets across all study groups, TRAM treatment had opposite effects on RA and HD samples: It decreased calcium influx in the Th2 and CD8 subsets in RA, while only Th1 cells were affected in HDs. The effects of IKCa1 channel inhibition are controversial in samples of RA and AS patients, since it shifts the inflammatory balance into the pro-inflammatory direction

Osteoimmunology in rheumatic diseases

This review summarizes the recent advances of osteoimmunology, a new research field that investigates the interaction of the immune system with the skeleton. Osteoimmunology has contributed significantly to the understanding of joint destruction in rheumatoid arthritis and other forms of arthropathies. In particular, the molecular regulation of osteoclast formation and its control by proinflammatory cytokines have helped investigators to understand the mechanisms of bone erosion in rheumatic diseases. Osteoimmunology has also allowed an improvement in our knowledge of the structure-sparing effects of antirheumatic drug therapy. Moreover, recent advances in the understanding of the molecular regulation of osteophyte formation are based on the characterization of the regulation of bone formation by inflammation. This review highlights the key insights into the regulation of bone destruction and formation in arthritis. Moreover, concepts of how bone influences the immune system are discussed

Increased expression of CD154 and FAS in SLE patients' lymphocytes

An increased level of apoptotic material and B cell activation leading to autoantibody production are hallmarks of systemic lupus erythematoses (SLE). Increased FAS expression, apoptosis, and CD154-mediated signaling, enabling T-B cell interaction are involved in the pathogenesis of SLE. This study addresses the expression profile of CD154 and FAS in the peripheral blood of patients with SLE, rheumatoid arthritis (RA) and normal healthy control donors. Surface markers on peripheral blood T and B cells from patients and healthy control donors were assessed using flow cytometry. The expression of CD154 and FAS were significantly increased in T and B cells of SLE patients as compared to healthy control donors and RA patients. In SLE and RA patients, FAS expression strongly correlated with CD154 expression on T cells, which was not found in healthy control donors. FAS expression was also associated with the occurrence of anti-DNA antibodies. We demonstrate high CD154 and FAS expression as a characteristic feature of SLE. This pattern may reflect simultaneous activation of apoptosis and activation of B-T cell interaction in SL