Objective To investigate the effects of different doses of dexmedetomidine pretreat-ment on cardiac toxicity of bupivacaine in rats.Methods Forty eight adult male SD rats weighing 250-300 g were randomly divided into 4 groups (n=12):saline control group (group C),dexmedetomi-dine 5 μg/kg group(group D5),dexmedetomidine 10 μg/kg group(group D10)and dexmedetomidine 1 5 μg/kg group(group D1 5 ).A Ⅱ-lead electrocardiogram(ECG)was continuously monitored,the femoral artery was cannulated for direct measurement of MAP and the femoral vein was cannulated for infusion of drugs.Groups D5,D10 and D1 5 were received infusion of dexmedetomidine 5,10 and 1 5μg/kg respectively 1 5 minutes before administration of bupivacaine,while the equal volume of saline was given in group C,then all rats received infusion 0.75% bupivacaine at the rate of 2 mg·kg-1· min-1 until asystole occurred.The doses of bupivacaine and the times of bupivacaine-induced convul-sions,arrhythmia and asystole were recorded respectively,and the myocardial concentration of bupiv-acaine was observed.Results Compared with group C,the doses of bupivacaine and the times of bupivacaine-induced convulsions,arrhythmia and asystole were all increased in groups D5,D10 and D1 5 (P <0.05).Compared with group D5,the above parameters were increased in groups D10 and D1 5 (P <0.05 ).There was no statistical significance of the above parameters between groups D10 and group D1 5.Conclusion Dexmedetomidine pretreatment can raise the threshold toxic dose of bupi-vacaine,delay the time of occurrence of cardiotoxicity of bupivacaine,so that to prevent the cardiac toxicities of bupivacaine in rats,and it produces a dose-dependent protective effect within a certain dose range.

Objective:To evaluate high-risk human papillomavirus (hrHPV) genotyping and viral load in predicting CIN (cervical intraepi-thelial neoplasia (CIN) grade 2 or worse in a Chinese rural area population with limited health resources. Methods:We performed a population-based prospective study and enrolled 2,257 women aged 35 to 64 years from three rural screening sites of Jiangxi prov-ince. We conducted a hybrid capture (HC-2) assay to predict viral load. A HC-2 relative light unit (RLU) threshold of 10 was set to differ-entiate samples between low (<10) and high (≥10) viral loads. We also carried out a HybriMax test to detect different hrHPV geno-types in the samples. Women exhibiting positive HC-2 or HybriMax results underwent colposcopy and colposcopically directed biopsy. Women with negative or positive hrHPV test results but with normal biopsy or CIN1 were followed-up for 24 months without interven-tion (n=2,211). We used histopathological findings as outcome. Results:Of the 2,211 women, 1,636 provided complete follow-up data. Of the 132 women with a high viral load, 4 (3.03%) developed CIN2+in the same period. The relative risk (RR) of CIN2+for HC-2 posi-tivity at baseline was 42.24 (95%CI=4.76-375.2). Of the 159 women who were positive for HPV16 or HPV18 upon screening, 4 (2.52%) progressed to CIN2+(RR=33.06, 95%CI=3.72-293.9). The 2-year cumulative incidence rates of CIN2+did not significantly differ be-tween the high viral load group and the HPV16/18 group. Conclusion:The risks of CIN2+progression were higher among women with a high viral load or HPV16/18 positivity than among women with negative hrHPV. Increasing the HC-2 cut-off value to 10 RLU or using HPV16/18 positivity may be similarly used to triage hrHPV-positive women for immediate colposcopy and comprehensive follow-up.Both approaches were equally predictive of the CIN2+risk in rural area. Increasing the HC-2 cut-off value to 10 RLU may also help allo-cate health resources effectively.

The vitamin-mineral enriched flour (VMF) was a byproduct obtained from a new processing technique of flour milling, and rich in vitamin B group, minerals and dietary fibers.The addition of 10 or 20% VMF to the stock diet composed mainly of white flour failed to improve PER and growth rate of young rats. When the rats were fed the tested diet for 6 weeks, in which the VMF served as the only diet source ot riboflavin, blood glutathione reductase activity coefficient was 1.13 and 1.09 respectively. This indicated that the amount of riboflavin supplied by VMF could maintain an adequate level in the body of the rats.Adult rats were fed high cholesterol plus 10, 20 and 30% VMF, the contents of serum cholesterol, liver lipids and liver cholesterol were similar to those of the normal diet group, these contents, however, in control group were increased obviously. The results suggested that VMF could protect the rats from the increment of serum cholesterol, liver lipids and cholesterol.

Objective To evaluate the effect of stellate ganglion block (SGB) on postoperative synaptic structure in hippocampal CA3 region in aged rats.Methods Seventy-two male Sprague-Dawley rats,aged 20-22 months,weighing 550-650 g,were randomly divided into 3 groups (n =24 each) using a random number table:control group (group C),operation group (group O) and SGB + operation group (group SGB).Group SGB received right SGB with 0.25％ bupivacaine 0.15 ml.Groups O and SGB underwent 30 min of exploratory laparotomy starting from 15 min after the end of administration.Y-maze test was performed on 1 day after operation in 6 rats chosen from each group for assessment of cognitive function.The frequency of standard training and standard time were recorded.Six rats were chosen from each group on 1,3 and 7 days after operation and sacrificed and the hippocampal CA3 region was isolated for microscopic examination and for measurement of synaptic structure.Results Compared with group C,the standard time was significantly prolonged,and the frequency of standard training was increased in groups O and SGB,the width of synaptic cleft was increased,the thickness of post-synaptic density was decreased,the length of active zones was shortened,and the curvature of the synaptic interface was decreased on 1,3 and 7 days after operation in group O (P ＜ 0.05),and no significant changes were found in each synaptic structure parameter in group SGB (P ＞ 0.05).Compared with group O,the standard time was significantly shortened,the frequency of standard training was decreased,the width of synaptic cleft was decreased,the thickness of the post-synaptic density was increased,the length of active zones was prolonged,and the curvature of the synaptic interface was increased on 1,3 and 7 days after operation in group SGB (P ＜ 0.05).Conclusion The mechanism by which SGB improves the postoperative cognitive dysfunction in aged rats may be related to inhibition of changes of synaptic structure in hippocampal CA3 region.