To study the effect of chitosan on delayed outward potassium current(IK) in single ventricular myocytes of guinea pig and investigate its antiarrhythmic mechanism from ion channel view. Patch clamp technique with whole-cell configuration. Holding potential was -40mV,commanding potential was -60- + 70mV ,step pulse +10mV,stimulating frequency 1 Hz,duration 300 ms and stimulating interval 6s. The result showed that Chitosan inhibited IK in a dose -dependent manner. Conclusion :Chitosan can inhibite IK in single ventricular myocytes of guinea pig.

OBJECTIVE： To analyze the trend of costs of various drugs consumed in hospitals of Guangzhou METHODS： The data were derived from the Hospital Purchasing of Drug Information System in Guangzhou from 1997 to 2000 The expense of each drug was calculated at the price of that year RESULTS： The annual increasing rates of drug expenses in 1998， 1999 and 2000 were 17 01％ ， 24 49％ ， 23 11％ respectively CONCLUSION： It is a matter of great urgency to rationally use drugs， to eliminate the waste of resources and to lighten the patients'burden

Objective To investigate the effect of channel density on the gating properties of Anoctamin 1(Ano1,TMEM16A)Ca2+?activated chlo?ride channel. Methods Ano1 expression plasmids were transiently transfected into HEK293 cells. High density and low density of Ano1 was ob?tained after expressing the protein for 24 h and 6 h,respectively. Electrophysiological recordings were performed in the whole?cell patch clamp con?figuration. The activation kinetics of current traces was fitted by exponentials. Results The current density was significantly higher in cells express?ing Ano1 for 24 h than those expressing Ano1 for 6 h(P<0.05). The activation of Ano1 current in cells with low density was well fit by a single expo?nential withτslow of 292.71±38.11 ms. The activation of Ano1 current in cells with high density was well fit by two exponentials withτfast of 47.78±4.58 ms andτslow of 385.74±71.44 ms. ANO1 current in cells with high density has a rapid active component(τfast)more than low density. There was no significantly different of theτslow between cells with high density and low density of Ano1(P>0.05). Conclusion Our findings suggested that chan?nel density regulates the gating of Ano1. High channel density promotes activation of Ano1.

OBJECTIVE:To analyze the trend of costs of various drugs consumed in hospitals of Guangzhou METHODS:The data were derived from the Hospital Purchasing of Drug Information System in Guangzhou from 1997 to 2000 The expense of each drug was calculated at the price of that year RESULTS:The annual increasing rates of drug expenses in 1998,1999 and 2000 were 17 01%,24 49%,23 11% respectively CONCLUSION:It is a matter of great urgency to rationally use drugs,to eliminate the waste of resources and to lighten the patients'burden

AIM To investigate the effect of N methyl berbamine(NMB)on ATP sensitive potassium currents( I KATP )in single ventricular myocytes of guinea pig. METHODS Patch clamp technique with whole cell configuration. Holding potential was -40 mV, commanding potential was -100～+50 mV and duration was 600 ms. Pipette solution contained 0 3 mmol?L -1 ATP. RESULTS NMB inhibited I KATP in a concentration dependent manner. When holding potential was -40 mV and command potential was 0 mV, I KATP were reduced from (0 46?0 09) nA, (0 43?0 15) nA, and(0 47?0 10) nA to (0 37?0 07) nA( n=4,P

Objective To investigate the expression of transmembrane protein 16 F (TMEM16 F) in breast cancer cells and to elucidate the effect of the knockdown of its gene on proliferation and migration of T47 D breast cancer cells. Methods The expression of TMEM16 F protein in MDA-MB-231 and T47 D breast cancer cells was detected by Western blotting. The effect of TMEM16 F knockdown on the proliferation of T47 D breast cancer cells was detected by CCK-8 cell proliferation assay, and its effect on the migration of T47 D breast cancer cells was examined by cell scratch assay. Results Western blotting results showed TMEM16 F protein expression in breast cancer cells.The results of CCK-8 cell proliferation assay showed that compared to the Scrambled shRNA group, the proliferation of T47 D breast cancer cells was decreased after TMEM16 F knockdown (P = 0.037 0). The results of the scratch test showed that the migration ability of T47 D breast cancer cells was enhanced after TMEM16 F knockdown, compared to the control group (P = 0.002 7). Conclusion TMEM16 F is highly expressed in T47 D breast cancer cells. Knockdown of TMEM16 F can inhibit the proliferation and promote the migration of T47 D breast cancer cells.

Objective To explore the feasibility of quartz glass for radiotherapy dosimetry through the experimental study of the thermoluminescence characteristics of synthetic quartz glass. Methods The thermoluminescence glow curves of quartz glass under different annealing conditions were analyzed, the thermoluminescence characteristics of quartz glass were studied, and the measurement parameters were optimized. Using the Co-60 reference radiation field in the National Secondary Standard Dosimetry Laboratory, the quartz glass samples under different annealing conditions were irradiated following the dose levels of radiotherapy, i.e., 0.5, 1.0, 2.0, 4.0, 6.0, 8.0, and 10.0 Gy, respectively. According to the relationship between the absorbed dose of quartz glass and the relative thermoluminescence signal intensity, the linearity and dispersion of the dose response of quartz glass were obtained, and the feasibility of quartz glass for radiotherapy dosimetry was analyzed. Results The linear correlation coefficient of dose response of quartz glass under annealing condition of 430℃ for 10 min was 0.9984, and the dose response dispersion was 0.97% at the absorbed dose of 2 Gy. The linear correlation coefficient of dose response of quartz glass under annealing condition of 600℃ for 1 h was 0.9911, and the dose response dispersion was 1.4% at the absorbed dose of 2 Gy. Conclusion Preliminary results suggest that quartz glass with annealing condition of 430℃ for 10 min has the potential to be used for radiotherapy dosimetry.