Objective:To establish the method validation of microbial limit tests for hospital paste preparations, including com-pound salicylic acid paste, zinc oxide paste and compound pine tar paste. Methods:According to the microbial limit test described in China pharmacopoeia 2010 edition, the method validation of count of bacteria, fungi and yeasts and tests for specified microorganisms was established. Results:Medium dilution method could be used in bacteria, fungi and yeasts count and specified microorganisms ex-amination for compound salicylic acid paste and zinc oxide paste. For compound pine tar paste, bacteria, fungi and yeasts count and the pseudomonas aeruginosa examination could use medium dilution method, while the staphylococcus aureus examination should employ membrane filtration method. Conclusion:The methods of microbial limit tests for the three hospital paste preparations are established, which can be used to control the quality of hospital preparations effectively.

Objective:To establish the microbial limit test methods for thirteen kinds of ointments. Methods:The microbial limit of 13 kinds of ointments was respectively determined by the routine method, culture medium dilution method and membrane filtration method. Results:The recovery of the tested bacteria in the samples was above 70% by the different methods. Conclusion:The micro-bial limit test methods for thirteen kinds of ointments are stablished, which may be used in the quality control.

Objective:To evaluate the relationship between dexmedetomidine-induced reduction of sevoflurane-induced neurotoxicity and cation-chloride cotransporters Na + -K + -2Cl --1 (NKCC1) /K + -2Cl --2 (KCC2) in neonatal rats. Methods:Eighty healthy male Sprague-Dawley rats at postnatal day 7 were divided into 4 groups ( n=20 each) using a random number table method: control group (group C), sevoflurane anesthesia group (group S), dexmedetomidine group (group D), and sevoflurane and dexmedetomidine group (group SD). Rats were exposed to 2.5% sevoflurane for 6 h to establish the model of sevoflurane anesthesia in group S. Dexmedetomidine 1.0 μg/kg was intraperitoneally injected, and then sevoflurane anesthesia was performed in group SD.The expression of cleaved caspase-3, NKCC1 and KCC2 was detected by Western blot at 24 h after the end of anesthesia.At 35 days after the end of anesthesia, the cognitive function was assessed using the Y maze test, and the neurons in the hippocampal CA1 area were counted using the Nissan staining method. Results:Compared with group C, the percentage of time spent in novel arm and the number of neurons in hippocampal CA1 area were significantly decreased, the expression of cleaved caspase-3 and NKCC1 was up-regulated, the expression of KCC2 was down-regulated, and the ratio of NKCC1/KCC2 was increased in S and SD groups ( P<0.05), and no change was found in the above indicators in group D ( P>0.05). Compared with group S, the percentage of time spent in novel arm and the number of neurons in hippocampal CA1 area were significantly increased, the expression of cleaved caspase-3 and NKCC1 was down-regulated, the expression of KCC2 was up-regulated, and the ratio of NKCC1/KCC2 was decreased in group SD ( P<0.05). Conclusion:The mechanism of dexmedetomidine attenuating sevoflurane-induced neurotoxicity may be related to maintaining the relatively stable expression of NKCC1/KCC2 in neonatal rats.