Increased Nitric Oxide Production and GFAP Expression in the Brains of Influenza A/NWS Virus Infected Mice

The cause of influenza to the brain was investigated using the A/NWS/33 influenza virus infected BALB/c mouse model. NOS-2 mRNA levels in the infected mouse brain was greater than in control mice in all brain regions examined, particularly in the olfactory bulb and hippocampus by 1 day p.i. On the contrary, no differences in NOS-1 or NOS-3 mRNA levels were found between infected and control mice. There was also a marked increase in the levels of metabolites of nitric oxide in the olfactory bulb and hippocampus. Immunohistochemistry showed positive staining for anti-NOS-2 primarily in the hippocampus of infected mice. Further, anti-NOS-2 and GFAP staining was mostly found around capillary blood vessels of the hippocampus starting early in the course of the disease. These results indicate that the NWS enhances the activation of astrocytes and NOS-2 expression which in turn enhances NO production and the expansion of capillary blood vessels

Antioxidative responses of oak species under ozone and water stress conditions

The Mediterranean basin is considered a global biodiversity hotspot but Mediterranean plants are threatened by natural and anthropogenic factors (e.g., tropospheric ozone, O3) which are expected to be harsher in the near future. The objective of this work was to give a thorough description of the detoxification mechanisms at the basis of the high plasticity of Mediterranean oak species. Two-year-old seedlings of Quercus ilex, Q. pubescens and Q. robur were grown under the combination of three levels of O3 (1.0, 1.2 and 1.4 times the ambient O3 concentration; AA, 1.2×AA and 1.4×AA) and water irrigation [1.2, 0.6 and 0.12 l day-1; well-watered (WW), moderate drought (MD) and severe drought (SD)] from June to October 2015. In Q. ilex, no symptoms due to O3 and/or drought were observed. This was confirmed by the minor propagation of reactive oxygen species (ROS) and the subsequent reduced cellular oxidative burst. Q. pubescens exposed to 1.4×AA and subjected to SD developed O3 injuries, consisting in minute roundish browning necrosis scattered among the leaf veins of both surfaces of mature leaves. An induction of the phenylpropanoid biosynthetic pathway by both stressors leaded to an increase of phenolic acids (+61% in comparison to AA). This enhanced antiradical ability of cell wall components partially balanced the ROS production but did not prevent foliar damage. In Q. robur, O3 symptoms were induced by both 1.2×AA and 1.4×AA concentrations under WW or MD conditions. Increasing O3 levels induced a significant rise of total flavonoids (+43 and +16% in 1.2×AA and1.4×AA). This species also displayed higher constitutive level of ascorbate. These mechanisms did not preserve the PSII photochemistry from impairment, as confirmed by the decrease of total chlorophylls under O3. A different species-specific degree of tolerance to single and combined stress was observed

Effect of conditioning and 1 year aging on the bond strength and interfacial morphology of glass-ionomer cement bonded to dentin

OBJECTIVE: The purpose of this study was to determine the bond stability and the change in interfacial ultra-structure of a conventional glass-ionomer cement bonded to dentin, with and without pre-treatment using a polyalkenoic acid conditioner. METHODS: The occlusal dentin surfaces of six teeth were ground flat. Glass-ionomer cement was bonded to the surfaces either with or without polyalkenoic acid conditioning. The teeth were sectioned into 1-mm2 stick-shaped specimens. The specimens obtained were randomly assigned to two groups with different periods of storage in water: 1 week and 1 year. The micro-tensile bond strength (μTBS) was determined for each storage time. Additional specimens were prepared for Transmission Electron Microscopy (TEM); they were produced with or without prior polyalkenoic acid conditioning in the same way as in the μTBS test. RESULTS: There was no significant difference in μTBS to conditioned dentin and non-conditioned dentin (p > 0.05). The failures appeared to be of a mixed nature, although aging caused more areas of cohesive than adhesive failure in both groups. The TEM observation showed an intermediate layer, a matrix-rich layer and a partially demineralized layer in the polyalkenoic acid conditioned group. SIGNIFICANCE: Aging did not reduce the bond strength of the conventional glass-ionomer cement to dentin with or without the use of a polyalkenoic acid conditioner.status: publishe