To determine the expression of components in Toll-like receptors (TLRs)/Nod-like receptors (NLRs)/ infiammasome/caspase-llinterleukin (IL-l)-P pathway, we examined the expression profiles of those genes by analyzing the data from expression sequence tag cDNA cloning and sequencing. We made several important findings: firstly, among 11 tissues examined, vascular tissues and heart express fewer types of TLRs and NLRs than immune and defense tissues including blood, lymph nodes, thymus and trachea; secondly, brain, lymph nodes and thymus do not express proinflammatory cytokines IL-IP and IL-18 constitutively, suggesting that these two cytokines need to be up regulated in the tissues; and thirdly, based on the expression data of three characterized inflammasomes (NALPl, NALP3 and IPAF inflammasome), the examined tissues can be classified into three tiers: the first tier tissues including brain, placenta, blood and thymus express inflammasome(s) in constitutive status; the second tier tissues have inflammasome(s) in nearly-ready expression status (with the requirement of upregulation of one component); the third tier tissues, like heart and bone marrow, require upregulation of at least two components in order to assemble functional inflammasomes. Our original model of three-tier expression of inflammasomes would suggest a new concept oftissue inflammation privilege, and provides an insight to the differences among tissues in initiating acute inflammation in response to stimuli.

We consider random walks over polymer chains (modeled as simple random walks or self-avoiding walks) and allow from each polymer site jumps to all Euclidean (not necessarily chemical) neighboring sites. For frozen chain configurations the distribution of displacements (DD) of a walker along the chain shows a paradoxal behavior: The DD's width (interquartile distance) grows with time as L~t a , with a ഠ 0.5, but the DD displays large power-law tails. For annealed configurations the DD is a Lévy distribution and its width is strongly superdiffusive.[S0031-9007 (97)03619-3] PACS numbers: 61.41. + e, 05.40. + j, 05.60. + wRandom walks in random environments occur in many fields of modern statistical physics and have won major attention in the last two decades; see Refs. [1][2][3]. Many situations lead to random walks on random walks (RW) or on self-avoiding random walks (SAW), see Refs. [4][5][6][7][8][9][10][11][12]; in the polymer case such structures depict chains in u solvents (RW) or in good solvents (SAW). The problem arises very naturally in the analysis of energy or exciton transport over polymer chains. For simplicity we view a moving entity (say electron, exciton, or enzyme) which performs steps of length a from one neighboring site (monomer) to another one. A triplet exciton, for instance, can move from one donor to another one close by, not necessarily sequentially placed along the chain. Hence not only steps along the chain but also steps between monomers which are close to each other in (Euclidean) space are involved, even if they are far apart in chemical space (where the distance l ch between two points is defined through the number of monomers n between them along the chain's backbone l ch n 1 1). Viewed in terms of the regular Euclidean distance some properties of random walks on SAW chains (e.g., the spectral dimension and the anomalous diffusion exponent) were evaluated in Refs. [4][5][6][7][8][9][10][11][12]. To our knowledge up to now, no particular attention was paid to the corresponding properties from the viewpoint of the chemical distance; here we show that this viewpoint leads to highly unusual behaviors.We start from the findings for frozen chain configurations in an experimentally relevant 3D situation, where we simulate nearest-neighbor random walks over RW and over SAW chains embedded in a simple cubic lattice. We first generate and save 100 chain configurations. The RW chains are generated as trajectories of a random walker on a simple cubic lattice, and their length is L 30 000. The SAW chains, of length L 10 000, were obtained using the pivot algorithm [13], as described in Ref. [14]. Each of the different realizations was created from an independent initial configuration to which the pivot transformation was applied 2000 times. Then for each configuration we start the walk at a random position and check at each step how many moves are possible from the actual position of the walker. The moves allowed are jumps to all monomers occupying nearest-neighbor positions (either along the ch...

We study random walks on a one-dimensional lattice that contains weak connections, so-called "bridges." Each time the walker crosses the bridge from the left or attempts to cross it from the right, the bridge may be destroyed with probability p; this restricts the particle's motion and directs it. Our model, which incorporates asymmetric aspects in an otherwise symmetric hopping mechanism, is very akin to "Brownian ratchets" and to front propagation in autocatalytic A+B-->2A reactions. The analysis of the model and Monte Carlo simulations show that for large p the velocity of the directed motion is extremely sensitive to the distribution of bridges, whereas for small p the velocity can be understood based on a mean-field analysis. The single-particle model advanced by us here allows an almost quantitative understanding of the front's position in the A+B-->2A many-particle reaction.

No abstract

No abstract