Induction of atypical EAE mediated by transgenic production of IL‐6 in astrocytes in the absence of systemic IL‐6

Interleukin (IL)‐6 is crucial for the induction of many murine models of autoimmunity including experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis. While IL‐6‐deficient mice (IL‐6 KO) are resistant to EAE, we showed previously that in transgenic mice with astrocyte‐targeted production of IL‐6‐restricted to the cerebellum (GFAP‐IL6), EAE induced with MOG_35–55 was redirected away from the spinal cord to the cerebellum. To further establish the importance of IL‐6 produced in the central nervous system, we have generated mice producing IL‐6 essentially only in the brain by crossing the GFAP‐IL6 mice with IL‐6 KO mice. Interestingly, GFAP‐IL6‐IL‐6 KO mice showed a milder but almost identical phenotype as the GFAP‐IL6 mice, which correlated with a lower load of inflammatory cells and decreased microglial reactivity. These results indicate that not only is cerebellar IL‐6 production and eventual leakage into the peripheral compartment the dominating factor controlling this type of EAE but that it can also facilitate induction of autoimmunity in the absence of normal systemic IL‐6 production. © 2013 Wiley Periodicals, Inc.     

Silent brain infarcts: A cause of depression in the elderly?

The present study included 1047 elderly participants. At baseline, brain magnetic resonance imaging (MRI) was performed to detect infarcts and white matter lesions; further, depressive disorders were assessed. Participants were followed up during 3.6 years to determine incident and recurrent depression. We found an increased risk of recurrent depression associated with silent brain infarcts.     

Effects of chemical composition on the corrosion of dental alloys

The aim of this study was to determine the effect of the oral environment on the corrosion of dental alloys with different compositions, using electrochemical methods. The corrosion rates were obtained from the current-potential curves and electrochemical impedance spectroscopy (EIS). The effect of artificial saliva on the corrosion of dental alloys was dependent on alloy composition. Dissolution of the ions occurred in all tested dental alloys and the results were strongly dependent on the general alloy composition. Regarding the alloys containing nickel, the Ni-Cr and Ni-Cr-Ti alloys released 0.62 mg/L of Ni on average, while the Co-Cr dental alloy released ions between 0.01 and 0.03 mg/L of Co and Cr, respectively.The open-circuit potential stabilized at a higher level with lower deviation (standard deviation: Ni-Cr-6Ti = 32 mV/SCE and Co-Cr = 54 mV/SCE). The potenciodynamic curves of the dental alloys showed that the Ni-based dental alloy with >70 wt% of Ni had a similar curve and the Co-Cr dental alloy showed a low current density and hence a high resistance to corrosion compared with the Ni-based dental alloys. Some changes in microstructure were observed and this fact influenced the corrosion behavior for the alloys. The lower corrosion resistance also led to greater release of nickel ions to the medium. The quantity of Co ions released from the Co-Cr-Mo alloy was relatively small in the solutions. In addition, the quantity of Cr ions released into the artificial saliva from the Co-Cr alloy was lower than Cr release from the Ni-based dental alloys.     

Clinical success of shade guides arranged according to lightness measured digitally

The aim of this study was to evaluate whether the VITA Classical shade guide arranged according to lightness allows clinicians to more often obtain a shade match than with an arrangement based on hue groups. A panel of 50 students determined the shade of the maxillary right central incisors of three patients with two differently arranged and blinded shade guides under standardized conditions. The L*a*b* values of the tabs were compared with those of the teeth spectrophotometrically. There were no statistically significant differences between the two arrangements. Using the arrangement according to lightness did not result in improved correct shade selection.     

In vitro evaluation of the metabolic stability of nine fragrance chemicals in trout and human hepatocytes

In vitro metabolic stability of nine fragrance chemicals: p-tolyl acetate, cashmeran, ethylene brassylate, celestolide, galaxolide, traseolide, ambretone, tonalide and pentadecanolide, was evaluated in trout and human hepatocytes. The compounds were incubated with trout hepatocytes at 12°C and human hepatocytes at 37°C. Quantification of compound disappearance with time was performed using gas chromatography/mass spectrometry. in vivo hepatic intrinsic clearance values were calculated from the in vitro data. Significant metabolism was observed with trout hepatocytes for five of the nine fragrance chemicals, while all nine were metabolized significantly with human hepatocytes. Previously published models were used to examine expected bioaccumulation and persistence in whole organisms. Calculated half-lives due to metabolism of the nine chemicals are significantly shorter for humans than trout: <1 hour and <1 day, respectively. For all chemicals with demonstrated hepatic metabolism, the models indicate a lack of accumulation. For those where metabolism was demonstrated in trout, calculated bioconcentration factors would not be classified as bioaccumulative under prevailing regulatory systems.     

CYP2B6, ABCB1 and OPRM1 profile in a stillborn affected by chronic methadone intoxication

Forensic Toxicology -