1.The Influence of Polycationic Polypetride on the Transfective Efficacy of NonViral Vector
Junmin LI ; Peikun TIAN ; Huiqiu JIANG ; Jianren GU
Chinese Journal of Cancer Biotherapy 1994;0(01):-
Objective: Purpose to investigate the different in vitro function of targetable non-viral vector containing poly-L-lysine or protamine. Methods: Using GV1 and GV2 targetable non-viral vectors, the influences of the poly-L-lysine and protamine on in vitro gene transfer efficiency and the course of gene expression were observed. Results: ?-galactosidase was expressed at intermediate level (50% ) in A375 cells using a complex containing either protamine or poly-L-lysine. Howerver, in case of ABAE cells, ?-galactosidase expression level was low (20% ) transferred with a comPlex containing protamine. On the contrary, ?- galactosidase expression was at high level (70% ) provided that protamine was replaced with poly-L-lysine. In addition, ?-galac- tosidase activity reached the peak at the 6th day after transfection with the complex containing protamine. The expression was not altered with subsequent subcultures, at least for 3 passages. Using poly-L-lysine, the expression peak in A375 reached the peak at the 7th day after transfection, but the level declined along with subsequent passages of cells. Conclusion: The apllication of protamine in VEGF receptor mediated gene delivery system was limited.
2.Time perception in patients with cerebellar lesion
Ping LIU ; Peikun XU ; Kai WANG ; Huaidong CHENG ; Yubao JIANG ; Chaoshi NIU
Chinese Journal of Neurology 2009;42(2):87-90
Objective To explore further the abilities of cerebellar lesions in skills of time estimation, and to test the hypothesis that cerebellum is involved in the special network of time perception. Methods Time reproduction was required for 3 time intervals of 600-milliseconds, 3 and 5 seconds with visual discrimination for control. Participants reproduce those time intervals after 1-second or 5-seconds of delay. Twenty-six patients with cerebellar lesions were compared to 26 healthy controls, matched for age, handedness, education. Results 600-milliseconds was overestimated by both cerebellar lesions and healthy controls, however, both 3-seconds and 5-seconds were underestimated. Patients with cerebellar lesions were significantly impaired on 600-milliseconds reproduction task ( delaying 1 s or 5 s, 1.37 ± 0.24, 1.26 ± 0.29 respectively, Z=-5.347, -4.230, both P<0.01). No group differences were found for the 3-seconds and 5-seconds time reproduction (delaying 1 s or 5 s, Z=-1.200,-0.092,-1.519, -0.723, all P>0.05). Conclusion The findings suggest that patients with cerebellar lesions perform poorly during measurement of the shorter interval, but show no impairment of longer intervals perception, supporting the hypotheses that cerebellum is specifically involved in the perception of sub-second intervals.
3.Determination of Phytolith-occluded Carbon Content Using Alkali Dissolution-Spectrophotometry
Jie YANG ; Yongfu LI ; Zhangting HUANG ; Peikun JIANG ; Tingting XIANG ; Yuqi YING
Chinese Journal of Analytical Chemistry 2014;(9):1389-1390
A method to determine phytolith-occluded carbon ( PhytOC) was explored. Sodium hydroxide solution was used to dissolve the silicon compound(SiO2 ·nH2O) which occluding on the carbon, and then potassium dichromate-sulphuric acid solution was used to oxidize the released organic carbon. The concentration of Gr3+produced from the reaction was measured by spectrophotometry with its absorbance at 590 nm wavelength. The organic carbon concentration was calculated based on the amounts of potassium dichromate consumed. This analytical method was verified well accuracy and repeatability by running standard addition and recovery experiments. It has the advantages of low carbon loss, easy to operate, low cost;and hardly any influence to body health, as compared with acid dissolution-Elementar Vario MAX CN method. The results obtained from this method have a good correlation with these determined by Elementar Vario MAX CN ( Germany) .