Effect of propofol and operative trauma on neurodevelopment and cognitive function of developing brain in rats / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of propofol and operative trauma on the neurodevelopment and cognitive function of the developing brain and its mechanism.</p><p><b>METHODS</b>A total of 104 postnatal day 13 Sprague-Dawley rats were randomly divided into 4 groups: control group (treated by 7.5 mL/kg saline and sham surgery), propofol group (treated by 75 mg/kg propofol), surgery group (with abdominal surgery under local anesthesia) and propofol+surgery group (with abdominal surgery under local anesthesia plus 75 mg/kg propofol anesthesia). Thirteen rats from each group were randomly selected for detecting the content of TNF-α in the hippocampus and the expression levels of caspase-3 and c-fos in the brain. Morris Water Maze test was used to detect the cognitive ability of the other rats at 60 days old, after which TNF-α content in the hippocampus and caspase-3 and c-fos expressions in the brain were detected.</p><p><b>RESULTS</b>In 13 day-old rats, TNF-α level and caspase-3 and c-fos expressions differed significantly between the surgery group and the other 3 groups (P<0.05) and were similar among the control group, propofol group and propofol+surgery group (P>0.05). In 60-day-old rats, Morris water maze test results, TNF-α level or expressions of caspase-3 and c-fos showed no significant differences among the 4 groups.</p><p><b>CONCLUSION</b>Abdominal surgery can induce inflammation in the hippocampus and neuroapoptosis in neonatal rats rather than adult rats. Single-dose propofol anesthesia does not significantly affect neurodevelopment of young rats, and can relieve central inflammatory reaction induced by surgical trauma.</p>

Rapid decolorization of dye Orange G by microwave enhanced Fenton-like reaction with delafossite-type CuFeO2.

Bimetallic oxide CuFeO2 as a new heterogeneous catalyst has shown much higher catalytic ability for activating peroxide than single-metal oxides. The present work demonstrated a synergistic microwave (MW) enhanced Fenton-like process with CuFeO2 for rapid decolorization of azo dye Orange G (OG). The MW irradiation dramatically enhanced the OG degradation efficiency, achieving 99.9% decolorization within 15min at pH5. The XRD analysis of reused CuFeO2, together with metal leaching tests, indicated merits of recycling for CuFeO2. The subsequent surface element analysis by XPS for fresh and used CuFeO2 showed a complex network for reactions between copper-iron redox pairs and surface hydroxyl groups, leading to a synergistic Fenton-like system accelerated by MW irradiation. In the CuFeO2 initiated Fenton-like reactions, several oxidant species (i.e., OH, O2-, electron hole, and FeIVO) responsible to the OG oxidation were identified by quenching experiments, showing the MW generated high temperature and "hot spots" enhanced the yield of OH by generation of electron-hole pairs. Further, the 26 detected degradation products confirmed the OH dominant oxidation of OG. This study shows that the MW-enhanced Fenton-like reaction using CuFeO2 has potential applications for rapid decolorization of dye effluent.

[Comparative study on accumulation of Ah-receptor agonists in contaminated soil based on EROD bioassay and chemical analysis].

The potential ecological risk by wastewater or reclaimed water for irrigation is of great concerns in recent years, but little work was done on the chronic toxicities through long term accumulation of persistent organic chemicals in soil. In present work, concentration of Ah-receptor agonists in soil organic extract was measured by an ethoxyresorfin O-deethylase (EROD) bioassay, which was calibrated and expressed by the 2, 3, 7, 8-tetrachlorodibenzo- p-dioxin (2, 3, 7, 8-TCDD) toxic equivalent (TEQbio). Simultaneously, 16 PAHs in soil were analyzed and their TEQs (total as TEQ(PAHs)) were calculated according to their toxic equivalent factors (TEFs) cited from literature. By bioassay, it was found that the concentration level of Ah-receptor agonists in soil irrigated using reclaimed water could be as high as 97.4 ng/kg, which was obviously higher than that in background soil using ground water irrigation regime (56.0 ng/kg). In comparing the results from bioassay and chemical analysis, the percentage of TEQ(PAHs) in TEQbio increased from 10.3% in background soil to 78.6% in the soil irrigated by reclaimed water. Use of reclaimed water for irrigation could result in the accumulation of Ah-receptor agonists in soil,and a major part of them in this case could be attributed to the accumulation of 16 priority PAHs in soils.

Genotoxic risk identification of soil contamination at a major industrialized city in northeast China by a combination of in vitro and in vivo bioassays.

The present study evaluated the genotoxicity of field soils in the Tianjin area, one of the most industrialized contaminated areas in northeast China. The genotoxicity of organic extracts of 41 soils was assayed by an in vitro SOS/ umu bioassay with Salmonella typhimurium TA 1535/pSK 1002. From the 41 soil samples, 11 samples were selected to confirm the genotoxic effect by in vivo single-cell gel electrophoresis (comet assay) using earthworms (Eisenia fetida). The results obtained demonstrated that, in the in vitro assay, genotoxicity expressed as induction ratios (IR) ranged from 1.00 to 4.60, and in the in vivo assay, the genotoxicity expressed as tail moment (TM) varied from 14.6 to 57.8 microm. All samples with high genotoxicity assessed by the SOS/umu bioassay possessed significantly high genotoxic effects in the comet assay, and there was a correlation (R2 = 0.736, p < 0.05) between IR and TM in both bioassays. It is concluded that soils in the Tianjin area were seriously contaminated by organic genotoxicants and higher levels of genotoxic effects existed in soils in the urban area of Tianjin as well as in areas near the coastal towns in the northeast part of the city. It can be concluded that a combination of in vivo and in vitro bioassays as a powerful and efficient genotoxicity-assessing tool could facilitate the assessment of genotoxic risk at a regional scale.

[Genotoxicity of soil irrigated by wastewater using umu/SOS test].

umu/SOS test is used to screen the accumulation of genotoxic substances in soil irrigated with wastewater in urban Beijing. The relative genotoxicity is evaluated based on the weight of soil used for extraction that could result in a positive reaction (or the induction ratio R equals 2) and the characteristics of genotoxic substances could be evaluated by the slop of linear part of the dose/effect relationship, R reaches the maximum when the amount of soil in each cell is about 10 mg. In a case study on a wastewater or reclaimed water irrigation area, the genotoxicity of soil samples could be observed and it may be attributed to the accumulation of PAHs, according to relevant information.