Soluble TNF Mediates the Transition from Pulmonary Inflammation to Fibrosis

BACKGROUND: Fibrosis, the replacement of functional tissue with excessive fibrous tissue, can occur in all the main tissues and organ systems, resulting in various pathological disorders. Idiopathic Pulmonary Fibrosis is a prototype fibrotic disease involving abnormal wound healing in response to multiple sites of ongoing alveolar epithelial injury. METHODOLOGY/PRINCIPAL FINDINGS: To decipher the role of TNF and TNF-mediated inflammation in the development of fibrosis, we have utilized the bleomycin-induced animal model of Pulmonary Fibrosis and a series of genetically modified mice lacking components of TNF signaling. Transmembrane TNF expression is shown to be sufficient to elicit an inflammatory response, but inadequate for the transition to the fibrotic phase of the disease. Soluble TNF expression is shown to be crucial for lymphocyte recruitment, a prerequisite for TGF-b1 expression and the development of fibrotic lesions. Moreover, through a series of bone marrow transfers, the necessary TNF expression is shown to originate from the non-hematopoietic compartment further localized in apoptosing epithelial cells. CONCLUSIONS: These results suggest a primary detrimental role of soluble TNF in the pathologic cascade, separating it from the beneficial role of transmembrane TNF, and indicate the importance of assessing the efficacy of soluble TNF antagonists in the treatment of Idiopathic Pulmonary Fibrosis

On the factorisation of the Pomeranchuk singularity in the Mueller- Regge diagrams

It is shown that the j plane singularity (Pomeron) which leads to a rising total cross-section like (lns)/sup epsilon /, epsilon >0, cannot be factorisable in the Mueller diagrams for inclusive production of particles with large rapidity difference. The relevance of this result for the theories of a renormalised Pomeron is discussed. (7 refs)

Linear Regge trajectories with a left-hand cut

The properties of boson Regge trajectories alpha (s) with a left-hand cut for s<0 are studied, with the following assumptions: (a) Re alpha (s) is linear in the physical region of the s and t channels. (b) The imaginary part is asymptotically smaller than the real part. (c) At s =0, alpha (s) has a branch point due to the existence of a Regge cut alpha /sub c/(s) in the angular momentum plane with alpha /sub c/(0)= alpha (0). The branch point is attributed to the collision of the physical pole alpha (s) with a second-sheet pole alpha (s), at s=0. (d) The function alpha (s) is analytic in the s plane. Under these assumptions the imaginary part for each boson trajectory is obtained in terms of a parameter A and a parameter-free universal function is determined by solving an integral equation numerically. The parameter A is determined by requiring that the first meson of each trajectory have the observed width. The model gives imaginary parts increasing almost linearly with s for large mod s mod . (10 refs)

Climate change due to heat and drought stress can alter the physiology of Maratheftiko local Cyprian grapevine variety

The effect of climate change (CC) on viticulture in Europe is of great concern and several international and indigenous grapevine cultivars have been examined for their adaptation to CC. In this study we focused on the short-term effects of light and moderate drought stress (DS) as well as heat stress (HS) on physiological and biochemical stress markers in Maratheftiko cultivar. We showed that leaf photosynthetic rate was decreased with DS and HS after 8 and 20 days. The leaf stomatal conductance was decreased in the case of DS after 8 days, while no differences could be found due to HS. Total phenols and flavonoids content and antioxidant capacity (FRAP and ABTS) were increased and seemed to be dependent on the relevant DS, HS and the period of stress exposure. Chlorophyll fluorescence was decreased in 50% volumetric water content (VWC) after 8 days of DS compared with the 100% VWC (control treatment). Leaf K and P content increased in moderate (50% VWC) irrigation stress and HS. Leaf hydrogen peroxide and lipid peroxidation increased after 8 days of DS, and this resulted in the increase of antioxidant enzymes activity. Overall, Maratheftiko performance against environmental stresses is related more to short-term DS than HS