1.Comparison of optimal parameters of electromagnetic impulse of electrochemotherapy for treatment of S-180 sarcomas
Baoyi WANG ; Hong ZHANG ; Zishu WANG ; Baoqiang XU
Chinese Journal of Tissue Engineering Research 2006;10(21):180-182
BACKGROUND: Electrochemotherapy(ECT) is a new and an efficient approach for the treatment of tumor. The technique is very easy to control and operate and is of little harm to normal tissue. Especially, it is very efficient in curing the superficial tumors. In the treatment process of ECT, the selection and constitute of electromagnetic impulse are the key factors.OBJECTIVE: To use the ECT as a therapeutic method for S-180 sarcomas in Kunming mice and obtain the optimal parameters of electromagnetic impulse in curing.SETTING: Department of Wireless Physics, College of Electronics-Information, Sichuan University DESIGN: Random grouping design and controlled experiment study MATERIALS: This experiment was conducted at the Laboratory of Cells, College of Life Sciences, Sichuan University from January 2003 to May 2004. Totally 106 Kunming mice were randomly divided into 12 groups: voltage 500 V, pulse number 5 and capacitance 6,10 and 14 μF, respectively in 3 groups, with 9 mice in each group;voltage 700 V, pulse number 5 and capacitance 6,10 and 14 μF, respectively in 3 groups, with 9 mice in each group; voltage 900 V, pulse number 5 and capacitance 6,10 and 14 μF, respectively in 3 groups,with 9 mice in each group; voltage 700 V, capacitance 10 μF, pulse number 7 and and 9 respectively in 2 groups , with 8 mice in each group , and control group with 9 mice in it.METHODS: The treatment includes injection of Bleomycin 0.04 mg per one (intraperitoneal injecting into tumors through multiple points), followed by application of electromagnetic impulse using the needles. The treatment was taken every three days andthree times in total. Mice were euthanized 18 days later. Tumor volume was measured before irradiation and 10 and 18 days after irradiation. Tumor volume (mm3)=3.141 59×length×width×height/6. Inhibitory rate(%)=(average tumor volume of the control group-average tumor volume after irradiation)/average tumor volume of control group×100%. The relative growth velocity=tumor volume after irradiation/Tumor volume before irradiation.MAIN OUTCOME MEASURES: Tumor volume; inhibitory rate; relative growth velocity RESULTS: Totally 106 animals were enrolled in the experiment and all of them entered the stage of result analysis. ①When the capacitance was 6 μF, the impulse numbers are 5, the voltage altered [for example the 10th day, when voltage was 500, 700, 900 V, the tumor volume was (66.99±91.17),(62.58±71.83),(78.43±73.91) mm3 , respectively]. The effect was the best when the voltage was 700 V, and was the worst when 900 V).②When the voltage and capacitance were fixed and the pulse numbers altered, for example voltage 700 V and capacitance 10 μF, taking the 10th day as the example , the pulse number was 5, 7 and 9, the tumor volume was (80.66±38.17),(41.33±36.40),(39.86±23.03) mm3, respectively. The inhibitory effect was better with the increase of pulse number, and the best when the pulse number was 9.CONCLUSION: According to experimental results, following parameters of electromagnetic impulse, can be concluded: ①The inhibitory effect is the best when the number of impulse is 5, voltage 700 V, capacitance 6 μF. ②The inhibitory effect increases with the increase of pulse number when the voltage is 700 V and capacitance is 10 μF, and is the best when the pulse number is 9.
2.Effect of enteral nutrition time on pH value of gastric juice and ventilator-associated pneumonia in critically ill patient
Shiqiong SU ; Rongqing SUN ; Ruifang LIU ; Zishu XU
Chinese Critical Care Medicine 2018;30(8):768-770
Objective To investigate the effect of enteral nutrition (EN) start time on pH value of gastric juice and ventilator-associated pneumonia (VAP) in critically ill patients with invasive mechanical ventilation, so as to provide reference for the rational selection of EN timing.Methods Patients with mechanical ventilation who underwent EN treatment admitted to the intensive care unit (ICU) of the First Affiliated Hospital of Zhengzhou University from January 1st, 2016 to November 30th, 2017 were enrolled, and the inclusion criteria were age ≥ 18 years, acute physiology and chronic health evaluation Ⅱ (APACHEⅡ) ≤ 15, and nutritional risk screening (NRS 2002) ≥ 3. Patients were divided into two groups according to the start time of EN: early EN group (implementation of EN within 48 hours after mechanical ventilation) and late EN group (implementation of EN after 48 hours after mechanical ventilation). The pH value of gastric juice, VAP incidence, mechanical ventilation time, and the length of ICU stay were compared between the two groups.Results A total of 108 patients were included, 54 in the early EN group and 54 in the late EN group respectively. The pH value of gastric juice in early EN group was lower than that in late EN group [4.8 (3.8, 5.8) vs. 5.6 (4.6, 6.6),P < 0.01]. There were 8 patients with VAP in the early EN group, 3 of whom were early onset VAP. There were 17 patients with VAP in the late EN group, 10 of whom were early onset VAP. The incidence of VAP and the incidence of premature VAP in the early EN group were significantly lower than those in the late EN group (14.8% vs. 31.5%, 5.6% vs. 18.5%, bothP < 0.05). The mechanical ventilation time [days: 7.5 (5.7, 9.0) vs. 8.6 (6.8, 10.7) and the length of ICU stay [days: 10.0 (8.5, 11.7) vs. 11.0 (9.5, 12.6)] in the early EN group were significantly shorter than those in the late EN group (allP < 0.05).Conclusion At the same time of protecting gastric mucosa, early EN is helpful to reduce the incidence of VAP, reduce the duration of mechanical ventilation and the length of ICU stay, and improve the prognosis.
3. Synergistic antibacterial effect of ursolic acid combined with fusidic acid on Staphylococcus aureus
Peng ZHANG ; Zishu WANG ; Lihong XU ; Xiangnan YIN ; Chunlin CHEN ; Wen HU
Chinese Journal of Clinical Pharmacology and Therapeutics 2022;27(6):608-613
AIM: To explore the antibacterial activity and underlying mechanism of ursolic acid combined with fusidic acid against Staphylococcus aureus (SA) ATCC29213 and Methicillin-Resistant Staphylococcus aureus (MRSA) ATCC43300 in vitro. METHODS: The minimum inhibitory concentration (MIC) of the combined use of ursolic acid and fusidic acid on SA, MRSA was determined by the micro broth dilution method and the micro checkerboard method, and the partial inhibitory concentration index (FICI) was calculated to determine the combined effect. And the bactericidal effect of fusidic acid combined with ursolic acid was studied by the time-killing curves. The agar double dilution method was used to determine the anti-drug resistance mutation concentration (MPC) and anti-drug resistance mutation selection window (MSW) of fusidic acid alone and in combination with ursolic acid. The viable count of biofilm carrier were determined by serial dilution method and the semi-quantitative biofilm by crystal violet staining method. RESULTS: The combined use of ursolic acid and fusidic acid for SA and MRSA FICI were 0.312 5 and 0.375, respectively. The time-killing curve showed that 1MIC ursolic acid combined with 1MIC fusidic acid has a synergistic bactericidal effect on SA and MRSA. The MPC of fusidic acid to MRSA was 256 μg/mL and the MSW was 256. After fusidic acid combined with ursolic acid, the MPC decreased to 8 μg/mL. The combined group was significantly reduced compared to the fusidic acid group. The semi-quantitative and biofilm bacterial counts of combined group were markedly decreased compared to the fusidic acid group after the biofilm cultivate for 48 h and 72 h.CONCLUSION: The combined use of UA and FA has a synergistic effect on SA and MRSA.