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We have performed magnetic susceptibility and high-field magnetization measurements on powder samples of Cu(DEP)Br (DEP=2,3-diethyl-pyrazine) and Cu(DMP)Cl (DMP=2,3-dimethyl-pyrazine) which are regarded as spin-1/2 two-leg spin-ladders in which the exchange constants are given by J along the leg and J along the rung. The temperature dependences of magnetic susceptibilities of these compounds show a round peak at 11 and 18 K, respectively, and are compared with those calculated with a density matrix renormalization group method for α= J/ J=0.45-0.55. The exchange constants of the former and the latter compounds are evaluated to be $J/k_{\rm B}=16.5~\mathrm{K}$ and $J/k_{\rm B}=28.4~\mathrm{K}$, respectively. No magnetization at 1.3 K appears in magnetic fields of up to about 5 T for Cu(DEP)Br and about 14 T for Cu(DMP)Cl, and then the magnetization increases monotonically to saturate at around 25 T and 38 T for respective compounds. Both magnetization curves are also compared with those calculated for α=0.45-0.55 using the same exchange parameter values as in the susceptibilities. [ABSTRACT FROM AUTHOR]

Background: Statins are widely used to treat hyperlipidaemia. Their immunosuppressive effect has recently been confirmed in various immune mediated disease models. However, relatively few studies have been conducted on allergic inflammation, so the precise mechanisms of their actions against allergies have not been fully clarified. On the other hand, the role of interleukin (IL)17 in immune responses has been recently highlighted, but whether statins affect IL17 production has not been well studied. The effect of pravastatin on allergic airway inflammation in a mouse model was examined to elucidate the mechanism of action, focusing on its effect on IL17 production. Methods: BALB/c mice were immunised with ovalbumin (OVA) and then challenged with OVA aerosol. Pravastatin was delivered by intraperitoneal injection during either sensitisation or the challenge. Results: When delivered during systemic sensitisation, pravastatin suppressed OVA induced proliferation and production of Th2 type cytokines such as IL5 in spleen cells ex vivo and in vitro, IL17 production was also suppressed. Furthermore, pavastatin delivered during the inhalation of OVA attenuated eosinophilic airway inflammation, OVA specific IgE production in serum and OVA induced IL17 production in the thoracic lymph node. We also found that pravastatin attenuated the antigen presenting capacity of CD11c+ cells obtained from the OVA challenged lung. Conclusion: Pravastatin suppresses the systemic sensitisation to allergen with downregulation of IL17 production. It also suppresses an ongoing immune response in the airway partly by suppressing antigen presentation in the lung. Therefore, statins could be a novel therapeutic option for treatment of asthma. [ABSTRACT FROM AUTHOR]

Background: Idiopathic pulmonary fibrosis is a devastating disorder for which there is no effective treatment. Transforming growth factor (TGF)-β plays a critical role in provoking fibrosis. Interleukin (IL)-10 is a potent immunosuppressive cytokine but its effect on the fibrosing process is unclear. A study was undertaken to examine whether IL-10 affects the production and activation of TGF-β and thus can attenuate the fibrosis. Methods: Mice were given an intratracheal injection of bleomycin. On day 1 or 14, IL-10 gene was delivered by rapid intravenous injection of Ringer's solution containing plasmid. Two weeks after the plasmid injection the mice were examined for fibrosis. The effect of IL-10 on TGF-β production by alveolar macrophages was assessed. Results: Even when delivered during the fibrosing phase, IL-10 gene significantly suppressed the pathological findings, hydroxyproline content, and production of both active and total forms of TGF-β1 in the lung. Immunohistochemical analyses showed that alveolar macrophages were one of the major sources of TGF-β1 and IL-10 diminished the intensity of the staining. IL-b also suppressed the expression of αvβ6 integrin, a molecule that plays an important role in TGF-β activation, on lung epithelial cells. Alveolar macrophages from bleomycin injected mice produced TGF-β1 spontaneously ex vivo, which was significantly suppressed by treatment of the mice in vivo or by treatment of the explanted macrophages vivo with IL-10. Conclusion: IL-10 suppresses the production and activation of TGF-β in the lung and thus attenuates pulmonary fibrosis, even when delivered in the chronic phase. [ABSTRACT FROM AUTHOR]

The density matrix renormalization group theory is reviewed as a numerical variational method. The variational state, expressed as a product of local tensors, is improved through locally tuning each tensor. The first section is a tutorial with simplified discussions. Details are discussed in the subsequent sections. The review concludes with some recent developments and future directions. [ABSTRACT FROM AUTHOR]