Over-expression of extracellular superoxide dismutase in mouse synovial tissue attenuates the inflammatory arthritis

Oxidative stress such as reactive oxygen species (ROS) within the inflamed joint have been indicated as being involved as inflammatory mediators in the induction of arthritis. Correlations between extracellular- superoxide dismutase (EC-SOD) and inflammatory arthritis have been shown in several animal models of RA. However, there is a question whether the over-expression of EC-SOD on arthritic joint also could suppress the progression of disease or not. In the present study, the effect on the synovial tissue of experimental arthritis was investigated using EC-SOD over-expressing transgenic mice. The over-expression of EC- SOD in joint tissue was confirmed by RT-PCR and immunohistochemistry. The degree of the inflammation in EC-SOD transgenic mice was suppressed in the collagen-induced arthritis model. In a cytokine assay, the production of pro-inflammatory cytokines such as, IL-1β, TNFα, and matrix metalloproteinases (MMPs) was decreased in fibroblast-like synoviocyte (FLS) but not in peripheral blood. Histological examination also showed repressed cartilage destruction and bone in EC-SOD transgenic mice. In conclusion, these data suggest that the over-expression of EC-SOD in FLS contributes to the activation of FLS and protection from joint destruction by depressing the production of the pro-inflammatory cytokines and MMPs. These results provide EC-SOD transgenic mice with a useful animal model for inflammatory arthritis research.     

Protective Effects of <em>Chlorella</em>-Derived Peptide Against UVC-Induced Cytotoxicity through Inhibition of Caspase-3 Activity and Reduction of the Expression of Phosphorylated FADD and Cleaved PARP-1 in Skin Fibroblasts

UVC irradiation induces oxidative stress and leads to cell death through an apoptotic pathway. This apoptosis is caused by activation of caspase-3 and formation of poly(ADP-ribose) polymerase-1 (PARP-1). In this study, the underlying mechanisms of Chlorella derived peptide (CDP) activity against UVC-induced cytotoxicity were investigated. Human skin fibroblasts were treated with CDP, vitamin C, or vitamin E after UVC irradiation for a total energy of 15 J/cm². After the UVC exposure, cell proliferation and caspase-3 activity were measured at 12, 24, 48, and 72 h later. Expression of phosphorylated FADD and cleaved PARP-1 were measured 16 h later. DNA damage (expressed as pyrimidine (6-4) pyrimidone photoproducts DNA concentration) and fragmentation assay were performed 24 h after the UVC exposure. Results showed that UVC irradiation induced cytotoxicity in all groups except those treated with CDP. The caspase-3 activity in CDP-treated cells was inhibited from 12 h onward. Expression of phosphorylated FADD and cleaved PARP-1 were also reduced in CDP-treated cells. Moreover, UVC-induced DNA damage and fragmentation were also prevented by the CDP treatment. This study shows that treatment of CDP provides protective effects against UVC-induced cytotoxicity through the inhibition of caspase-3 activity and the reduction of phosphorylated FADD and cleaved PARP-1 expression.     

RF-related heating assessment of extracranial neurosurgical implants at 7 T

Purpose

The purpose was to evaluate radiofrequency (RF)-related heating of commonly used extracranial neurosurgical implants in 7-T magnetic resonance imaging (MRI).

Materials and methods

Experiments were performed using a 7-T MR system equipped with a transmit/receive RF head coil. Four commonly used titanium neurosurgical implants were studied using a test procedure adapted from the American Society for Testing and Materials Standard F2182-11a. Implants (n = 4) were tested with an MRI turbo spin echo pulse sequence designed to achieve maximum RF exposure [specific absorption rate (SAR) level = 9.9 W/kg], which was further validated by performing calorimetry. Maximum temperature increases near each implant's surface were measured using fiberoptic temperature probes in a gelled-saline-filled phantom that mimicked the conductive properties of soft tissue. Measurement results were compared to literature data for patient safety.

Results

The highest achievable phantom averaged SAR was determined by calorimetry to be 2.0 ± 0.1 W/kg due to the highly conservative SAR estimation model used by this 7-T MR system. The maximum temperature increase at this SAR level was below 1.0 °C for all extracranial neurosurgical implants that underwent testing.

Conclusion

The findings indicated that RF-related heating under the conditions used in this investigation is not a significant safety concern for patients with the particular extracranial neurosurgical implants evaluated in this study.     

A switchable molecular rotator: neutron spectroscopy study on a polymeric spin-crossover compound

A quasielastic neutron scattering and solid-state (2)H NMR spectroscopy study of the polymeric spin-crossover compound {Fe(pyrazine)[Pt(CN)(4)]} shows that the switching of the rotation of a molecular fragment--the pyrazine ligand--occurs in association with the change of spin state. The rotation switching was examined on a wide time scale (10(-13)-10(-3) s) by both techniques, which clearly demonstrated the combination between molecular rotation and spin-crossover transition under external stimuli (temperature and chemical). The pyrazine rings are seen to perform a 4-fold jump motion about the coordinating nitrogen axis in the high-spin state. In the low-spin state, however, the motion is suppressed, while when the system incorporates benzene guest molecules, the movements of the system are even more restricted.     

Phase diagram of electron-hole systems: Interplay between exciton Mott transition and quantum pair condensation

Quasi-thermal-equilibrium states of electron-hole (e-h) systems in photoexcited insulators are studied from a theoretical viewpoint, stressing the exciton Bose-Einstein condensation (BEC), the e-h BCS-type pair-condensed state, and the exciton Mott transition between an insulating exciton/biexciton gas phase and a metallic e-h plasma phase. We determine the quasi-equilibrium phase diagram of the e-h system at zero and finite temperatures with applying the dynamical mean-field theory (DMFT) to the e-h Hubbard model with both repulsive and attractive on-site interactions. Effects of inter-site interactions on the exciton Mott transition are also clarified with applying the extended DMFT to the extended e-h Hubbard model.     

Synthesis and anti‐inflammatory effect of morachalcone B,morachalcone C,and analogs

An efficient method to synthesize morachalcones B and C ( 1 and 2 ) is described. Rap?Stoermer condensation and 1,3‐prenyl rearrangement were used as two key synthetic methods. Morachalcone C was obtained by photo‐oxygenation of morachalcone B. Morachalcones B and C showed moderate anti‐inflammatory activity.     

Crystal structure of the flagellin protein FlaG from Helicobacter pylori

Flagella, comprising flagellin proteins, are essential virulence factors for Helicobacter pylori to colonize human stomach mucosa. The flagellin‐associated flaG operon of H. pylori consists of the flaG, fliD, and fliS genes under the control of a σ²⁸‐dependent promoter. The flaG gene is involved in chemotaxis and motility. We cloned, expressed, and purified the H. pylori flaG gene encoding the flagellin protein HpFlaG. Sequence alignment revealed that HpFlaG exhibits low sequence identity with other FlaG proteins. Overall, N‐terminal sequences of FlaG proteins are mostly divergent, and C‐terminal regions might be important for dimer interactions between protein subunits. Here, we report the crystal structure of the N‐terminal truncated protein (NT‐HpFlaG), as determined by multiwavelength anomalous dispersion at a resolution of 2.7 å. The overall structure of NT‐HpFlaG consists of two helices and three strands, folded into a palm‐like conformation. Two monomers strongly interact as a dimer by hydrophobic coiled‐coil interactions. Based on our structure, we suggest that the functional state of HpFlaG is as a dimer.     

Momentum-transport studies in high E x B shear plasmas in the National Spherical Torus Experiment

Experiments have been conducted at the National Sperical Torus Experiment (NSTX) to study both steady state and perturbative momentum transport. These studies are unique in their parameter space under investigation, where the low aspect ratio of NSTX results in rapid plasma rotation with ExB shearing rates high enough to suppress low-k turbulence. In some cases, the ratio of momentum to energy confinement time is found to exceed five. Momentum pinch velocities of order 10-40 m/s are inferred from the measured angular momentum flux evolution after nonresonant magnetic perturbations are applied to brake the plasma.     

Two‐dimensional LC‐MS/MS to enhance ceramide and phosphatidylcholine species profiling in mouse liver

A two‐dimensional (2D) hydrophilic interaction liquid chromatography (HILIC) and reverse‐phase (RP) liquid chromatography (LC) system coupled with triple‐quadrupole mass spectrometry (MS) was developed to comprehensively profile ceramides and phosphatidylcholine in extracted biological samples. Briefly, the 2D HILIC‐RPLC system used a silica HILIC column operated in the first dimension to distinguish the lipid classes and a BEH C₁₈ column operated in the second dimension to separate the lipid species of the same class. The regression linearity of each lipid was satisfactory in both systems; however, the absolute matrix effect factor was reduced in 2D LC‐MS/MS system. Limits of detection of 2D LC‐MS/MS system were 2‐ to 3‐fold lower compared with one‐dimensional RPLC‐MS/MS. The recovery from the sample ranged from 84.5 to 110%. To summarize, the developed method was proven to be accurate and producible, as relative standard deviations remained <20% at three spiked levels. The efficiency of this newly developed system was applied to measure changes of lipids in the liver of mice after naphthalene treatment. Orthogonal projection to latent structures‐discriminant analysis discriminated the lipids from control and the treatment group. We concluded that 2D LC‐MS/MS is a promising method to assist lipidomic studies of complex biological samples. Copyright © 2014 John Wiley & Sons, Ltd.     

Cu-site-substituted REBa2Cu3O7-δ single crystals by top-seeded solution-growth (RE=rare earth element)

Using the top-seeded solution-growth (TSSG) method, Cu-site-substituted REBa₂Cu₃O_7-δ single crystals (REBCO, RE=rare earth elements) were grown. For theoretical studies and practical applications, metal element M (M=Zn, Fe, Ni, Al and Mg) was used for substitution. The optimal processes led to high-quality crystals with sufficient dimension at a high doping level. Thermodynamic and kinetic problems of growing M-doped REBCO crystals are discussed, including the M substitution limit in crystal, the effect of solvent composition on the M substitution in crystal, the crystal growth model of the M-doped REBCO, the phase relation of RE–Cu–M–O systems and composition/property control.