Perfusion of gastrodin in abdominal aorta for alleviating spinal cord ischemia reperfusion injury

OBJECTIVE@#To observe the effects of perfusion of the gastrodin in abdominal aorta for alleviating the spinal cord ischemia reperfusion injury (SCIRI).@*METHODS@#A total of 36 New Zealand white rabbits were divided randomly into sham-operated group (group S), control group (group C) and gastrodin group (group G), 12 rabbits for each group. Aorta abdominalis infrarenalis blocking method was applied to establish the SCIRI model. The changes of motor evoked potentials (MEPs) before the ischemia and on 30 min, 60 min, 6 h, 12 h and 24 h of reperfusion of the gastrodin were respectively recorded, and the neurologic function score before the ischemia, on the 6 h, 12 h and 24 h of the reperfusion of the gastrodin were assessed. And the changes of the concentration of serum neuron specific enolase (NSE), interleukin (IL)-lβ and IL-8 were measured before the ischemia, after 45 min of ischemia, and on 30 min, 60 min, 6 h, 12 h and 24 h of reperfusion of gastrodin. Then the levels of spinal cord nerve cells mitochondrial superoxide dismutase (SOD), reactive oxygen species (ROS), glutathione peroxidase (GSH-PX), malondialdehyde (MDA), total antioxidant capacity (T-AOC) and mitochondrial swelling degree (MSD) were tested and the histopathologic changes in spinal cord tissues were observed.@*RESULTS@#The levels of the NSE, IL-lβ, IL-8, ROS, MDA and MSD of group C were all significantly elevated after the ischemia (P < 0.01); the levels of the spinal nerve cell mitochondria SOD, GSH-PX and T-AOC were all significantly reduced (P < 0.01), MEPs and spinal cord tissue pathology were damaged significantly (P < 0.01). The rate of motor neuron abnormalities and the damages of spinal cord tissue pathology of group G were significantly milder than those of group C (P < 0.01); the levels of NSE, IL-lβ, IL-8, ROS, MDA and MSD were significantly lower than those of group C (P < 0.01), but the levels of SOD, GSH-PX and T-AOC were all significantly higher than those of group C (P < 0.01), and the recovery of neurologic function score during the reperfusion of gastrodin was significantly faster than group C (P < 0.01).@*CONCLUSIONS@#Perfusion of the gastrodin in abdominal aorta can alleviate the spinal cord ischemia reperfusion injury by promoting the mitochondrial antioxidant capacity and inhibiting the inflammatory reaction.

Perfusion of gastrodin in abdominal aorta for alleviating spinal cord ischemia reperfusion injury

Objective To observe the effects of perfusion of the gastrodin in abdominal aorta for alleviating the spinal cord ischemia reperfusion injury (SCIRI). Methods A total of 36 New Zealand white rabbits were divided randomly into sham-operated group (group S), control group (group C) and gastrodin group (group G), 12 rabbits for each group. Aorta abdominalis infrarenalis blocking method was applied to establish the SCIRI model. The changes of motor evoked potentials (MEPs) before the ischemia and on 30 min, 60 min, 6 h, 12 h and 24 h of reperfusion of the gastrodin were respectively recorded, and the neurologic function score before the ischemia, on the 6 h, 12 h and 24 h of the reperfusion of the gastrodin were assessed. And the changes of the concentration of serum neuron specific enolase (NSE), interleukin (IL)-lβ and IL-8 were measured before the ischemia, after 45 min of ischemia, and on 30 min, 60 min, 6 h, 12 h and 24 h of reperfusion of gastrodin. Then the levels of spinal cord nerve cells mitochondrial superoxide dismutase (SOD), reactive oxygen species (ROS), glutathione peroxidase (GSH-PX), malondialdehyde (MDA), total antioxidant capacity (T-AOC) and mitochondrial swelling degree (MSD) were tested and the histopathologic changes in spinal cord tissues were observed. Results The levels of the NSE, IL-lβ, IL-8, ROS, MDA and MSD of group C were all significantly elevated after the ischemia (P < 0.01); the levels of the spinal nerve cell mitochondria SOD, GSH-PX and T-AOC were all significantly reduced (P < 0.01), MEPs and spinal cord tissue pathology were damaged significantly (P < 0.01). The rate of motor neuron abnormalities and the damages of spinal cord tissue pathology of group G were significantly milder than those of group C (P < 0.01); the levels of NSE, IL-lβ, IL-8, ROS, MDA and MSD were significantly lower than those of group C (P < 0.01), but the levels of SOD, GSH-PX and T-AOC were all significantly higher than those of group C (P < 0.01), and the recovery of neurologic function score during the reperfusion of gastrodin was significantly faster than group C (P < 0.01). Conclusions Perfusion of the gastrodin in abdominal aorta can alleviate the spinal cord ischemia reperfusion injury by promoting the mitochondrial antioxidant capacity and inhibiting the inflammatory reaction.

Shear bond strengths between alumina-toughened zirconia cores and veneering ceramics and their susceptibility to aging

OBJECTIVE@#To evaluate the shear bond strength (SBS) between alumina-toughened zirconia (ATZ) cores and veneering ceramics, investigate the effect of aging in artificial saliva on SBS and compare it with that of yttria-stabilized tetragonal zirconia polycrystals(Y-TZP).@*METHODS@#Bars of ATZ and Y-TZP were layered with veneering ceramics in accordance to the recommendation of the manufacturer. Half of each group (n = 10) was aged at 134 °C (under 2 bar pressure) in an autoclave for 48 h. Subsequently, all specimens were subjected to shear force in a universal testing machine. The interface and fractured surface of the specimens were evaluated using scanning electron microscopy and X-ray energy dispersive spectroscopy.@*RESULTS@#The initial mean SBS values in MPa±SD were 28.9±8.0 for ATZ and 26.2±7.6 for Y-TZP. After aging, the mean SBS values for ATZ and Y-TZP were 22.9±4.9 MPa and 22.8±6.9 MPa, respectively. Neither the differences between the SBS values of the ATZ and Y-TZP groups nor the influence of aging on all groups were statistically significant.@*CONCLUSIONS@#The SBS between the ATZ core and the veneering ceramics was not affected by aging. The SBS of ATZ to veneering ceramics was not significantly different compared with that of Y-TZP.

Evaluation of alumina effects on the mechanical property and translucency of nano-zirconia all-ceramics / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To study the effects of alumina content on sintered density, mechanical property and translucency of zirconia nanocomposite all-ceramics.</p><p><b>METHODS</b>Specimens of zirconia nanocomposite all-ceramics were divided into five groups based on their alumina content which are 0% (control group), 2.5%, 5.0%, 7.5% and 10.0% respectively. The sintered densities were measured using Archimedes' method. Specimens' bending strengths were measured with three-point bending test (ISO 6872). The visible light transmittances were measured with spectrophotometric arrangements and the fractured surfaces were observed using scanning electron microscope (SEM).</p><p><b>RESULTS</b>The control group of pure zirconia could be sintered to the theoretical density under pressure-less sintering condition. The bending strength was (1100.27 ± 54.82) MPa, the fracture toughness was (4.96 ± 0.35) MPa×m(1/2) and the transmittance could reach 17.03%. The sintered density and transmittance decreased as alumina content increased from 2.5% to 10%. However, the fracture toughness only increased slightly. In all four alumina groups, the additions of alumina had no significant effect on samples' bending strengths (P > 0.05). When the content of alumina was 10%, fracture toughness of specimens reached (6.13 ± 0.44) MPa×m(1/2) while samples' transmittance declined to 6.21%. SEM results showed that alumina particles had no significant effect on the grain size and distribution of tetragonal zirconia polycrystals.</p><p><b>CONCLUSIONS</b>Additions of alumina to yttria-tetragonal zirconia polycrystals could influence its mechanical property and translucency. Additions of the other phase to zirconia ceramics should meet the clinical demands of strength and esthetics.</p>