【摘要】目的评价双氯芬酸钠滴眼液在准分子激光上皮下角膜磨镶术(LASEK)中的临床应用价值。方法2008年7月2009年3月行LASEK术患者80例160眼,屈光度范围-4.86D±2.15D(-1.25D～-6.50D),随机分为双氯芬酸钠滴眼液组(试验组)和对照组,对两组术后角膜刺激症状、上皮愈合情况进行对比观察和统计学分析。结果试验组术后第1、3天角膜刺激症状明显轻于对照组(P＜0.05),上皮愈合速度较对照组更快(P＜0.05)。结论在LASEK术中合理使用双氯芬酸钠滴眼液,可明显减轻术后患者角膜刺激症状,促进角膜上皮的更快愈合。
Patch clamp is a technique that can measure weak current in the level of picoampere (pA). It has been widely used for cellular electrophysiological recording in fundamental medical researches, such as membrane potential and ion channel currents recording, etc. In order to obtain accurate measurement results, both the resistance and capacitance of the pipette are required to be compensated. Capacitance compensations are composed of slow and fast capacitance compensation. The slow compensation is determined by the lipid bilayer of cell membrane, and its magnitude usually ranges from a few picofarads (pF) to a few microfarads (μF), depending on the cell size. The fast capacitance is formed by the distributed capacitance of the glass pipette, wires and solution, mostly ranging in a few picofarads. After the pipette sucks the cells in the solution, the positions of the glass pipette and wire have been determined, and only taking once compensation for slow and fast capacitance will meet the recording requirements. However, when the study needs to deal with the temperature characteristics, it is still necessary to make a recognition on the temperature characteristic of the capacitance. We found that the time constant of fast capacitance discharge changed with increasing temperature of bath solution when we studied the photothermal effect on cell membrane by patch clamp. Based on this phenomenon, we proposed an equivalent circuit to calculate the temperature-dependent parameters. Experimental results showed that the fast capacitance increased in a positive rate of 0.04 pF/℃, while the pipette resistance decreased. The fine data analysis demonstrated that the temperature rises of bath solution determined the kinetics of the fast capacitance mainly by changing the inner solution resistance of the glass pipette. This result will provide a good reference for the fine temperature characteristic study related to cellular electrophysiology based on patch clamp technique.
Objective To investigate the protective mechanism of ulinastatin（UTI） in pulmonary microvascular endothelial cells （PMVECs） attacked by serum from the patients with severe sepsis. Methods PMVECs were cultured in vitro and randomly divided into 4 groups，ie. a normal group （culture medium with 10% fetal bovine serum，group N），a health group （culture medium with 10% healthy human serum，group H），a patient group （culture medium with 10% human septic shock serum，group S），and a ulinastatin group （culture medium with 1000 U/mL UTI and 10% human septic shock serum，group U）. The proliferation activity of PMVECs was measured by MTT expressed by optical density （OD）. The concentration of TNF-α in supernatant of culture medium was examined by ELISA at 0，1，2，4，6 hours. The expression of NF-κB was examined by immunohistochemistry at 1 hour. Results Compared with group N，the cell proliferation activity of group S decreased significantly，and the cell proliferation activity of group U decreased slightly at each time poi nt. Compared with group N，the cell proliferation activity of group S and group U at 1，4，6 hours were significant different （Plt;0.05 ）. Compared with group S，the cell proliferation activity of group U at 1，2，6 hours increased significantly （Plt;0.05）. Obviously positive expression of NF-κB in PMVECs could be seen in group S，a little positive expression in group S，and no expression in group N and group H. Compared with group N，the TNF-α levels of group S and group U increased significantly at each time point with significant differences （Plt;0.01）. Compared with group S，the TNF-α levels were significantly reduced at each time point in group U （Plt;0.01）. Conclusions UTI can reduce the release of TNF-α by inhibiting NF-κB activation，thus reduce PMVECs injury attacked by serum from severe sepsis patients.