OBJECTIVE:To establish a method for the content determination of polymer in cefatrizine propylene glycol. METHODS:High performance sephadex gel chromatography was performed on the column of Sephadex G-10 with mobile phase A of 0.01 mol/L phosphate buffer [0.01 mol/L Disodium hydrogen phosphate solution-0.01 mol/L Sodium dihydrogen phosphate solution (61∶39,V/V)](pH7.0)and mobile phase B of water at a flow rate of 1.0 ml/min,the detection wavelength was 254 nm,column temperature was 30℃,and volume injection was 200μl. RESULTS:The linear range of polymer was 2.07-103.30 mg/ml(r=0.999 4);the limit of quantitation of 10.4 ng,limit of detection was 4.1 ng;RSDs of precision and reprodicibility tests were lower than 3%. CONCLUSIONS:The method is specific with high sensitivity and good reproducibility,and can be used for the content determination of polymer in active pharmacentical ingredient cefatrizine propylene glycol.

OBJECTIVE It's known that post-retrieval extinction but not extinction alone could erase fear memory.However,whether the coding pattern of original fear engrams is remod-eled or inhibited remains largely unclear.Here we try to investigate whether the coding pattern of memory engrams is altered during post-retrieval extinction induced memory updating.METHODS To answer the question,by using activity-depen-dent neuronal-tagging technology,neuronal trac-ing technique combined with optogenetic manipu-lation and in vivo calcium imaging,we identified the fear and extinction cells in PrL and BLA and investigated the dynamic encoding of memory engram ensembles in the PrL and BLA during CS versus US initiated memory updating.RESULTS We found increased reactivation of engram cells in the prelimbic cortex and basolat-eral amygdala during memory updating.More-over,conditioned stimulus and unconditioned stimulu sinitiated memory updating depend on the engram cells reactivation in the prelimbic cor-tex or basolateral amygdala respectively.Finally,we found memory updating causes increased overlapping between fear and extinction cells and the original fear engrams encoding was altered during memory updating.CONCLUSION Our data provide the first evidence to show the overlapping ensembles between fear and extinc-tion cells and functional reorganization of original engrams underlying conditioned stimulus and unconditioned stimulus initiated memory updating.

OBJECTIVE: To observe the therapeutic effect of different doses of dihydroartemisinin (DHA) on atopic dermatitis (AD) in mice and explore the mechanism. METHODS: Forty-two C57BL/6 mice were randomly divided into 7 groups ( RESULTS: Treatment with 25, 75, and 125 mg/kg DHA and dexamethasone all alleviated AD symptoms of mice, reduced the severity scores of skin lesions, and ameliorated pathological changes of the skin tissue. DHA at 125 mg/kg produced the most obvious therapeutic effect and significantly alleviated mast cell infiltration in the lesions as compared with the other treatment groups ( CONCLUSIONS DHA is effective for the treatment of AD in mice with an optimal dose of 125 mg/kg. The therapeutic effect of DHA is achieved probably through regulation of local immunity by inhibiting mast cell infiltration in the lesions.
Animals ; Anti-Inflammatory Agents/therapeutic use* ; Artemisinins ; Cytokines ; Dermatitis, Atopic/drug therapy* ; Immunoglobulin E ; Mast Cells ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; Skin