1.Improvement of Detection Sensitivity of Triglyceride with Methylamine Formate as Ionization Enhancer in Reversed Phase Liquid Chromatography-Electrospray Ionization Mass Spectrometry
Haiyan ZHAO ; Can GONG ; Xu XU
Chinese Journal of Analytical Chemistry 2017;45(9):1323-1329
A novel ionization enhancer, methylamine formate, was proposed for improving the detection sensitivity of triglyceride in edible oil by reversed phase liquid chromatography electrospray ionization mass spectrometry (LC-ESI-MS).The commonly used isopropanol-acetonitrile-methanol-water and isopropanol-acetonitrile were selected as the mobile phase.By using a reversed phase C18 column, and taking the corn oil in isopropyl alcohol as sample solution, we compared methylamine formate with ammonium formate, as ionization enhancers, for their effect on the detection sensitivity of triglyceride by LC-ESI-MS after screening other different ionization enhancers, such as formic acid, acetic acid, ammonium formate, ammonium acetate, butyl formate, dibutylamine formate, triethylamine formate, diethylamine formate, methylamine formate, and ethylamine formate.The result indicated that, by using methylamine formate, the mass spectral peak response and the signal to noise ratio for trilinoleic glyceride component were 5 times higher than that of ammonium formate.The effect of the concentration of methylamine formate ionization enhancer, the flow rate of the mobile phase and the flow rate of nebulizing gas on the detection of methylamine formate were investigated.The concentration of triglyceride components in corn oil starting to form aggregates was similar in different mobile phases in the electrospray process according to measurement of the relationship between corn oil concentrations and the total ion chromatogram peak area of triglyceride.In particular, the peak area of trilinolein was linear with its concentration in the range of 7×10-7-2×10-4 mol/L (R2=0.9997), but increased slower in the higher concentration range.According to the experimental data, the mechanism for improvement of detection sensitivity of methylamine formate was suggested as that the addition of methylamine mono-charged ions with hydrophobic groups had lower solvation energy, which made the enriched addition ions easily evaporation from the droplet surface, thus improving the electrospray ionization efficiency.This method provided an effective way to improve the detection sensitivity of triglyceride in edible oil by LC-ESI-MS.
2.Study Advances in Synergism and Detoxication of Drug Combination with Cisplatin in Chemotherapy
Hong YANG ; Can GONG ; Changhong WANG ; Cong QI
China Pharmacist 2015;(5):836-840
Cisplatin is effective in the treatment of various solid tumors. However, its clinical application is limited because of the severe side-effects such as nephrotoxicity, hepatotoxicity, ototoxicity and so on. Drug combination is advocated in clinics for synergism and detoxication. In order to provide some referencs for the research of drug combination and clinical treatment regimen, the research advances in the synergism and detoxication of drug combination of cisplatin with chemicals/ traditional Chinese medicines in recent years are reviewed in the paper.
3.Matrix-assisted Laser Desorption/Ionizaiton-Mass Spectrometry Imaging of Oligosaccharides in Soybean and Leaf Using Ionic Liquid as Matrix
Xingli PEI ; Yuyu HUANG ; Can GONG ; Xu XU
Chinese Journal of Analytical Chemistry 2017;45(8):1155-1164
The ionic liquid butylamine 2,5-dihydroxybenzoate (DHB-BuN) was chosen as the matrix for improving repeatability of oligosaccharides quantitation, and imaging oligosaccharides in soybean and leaf by matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS).Using the ionic liquid matrix methanol solution (20%, V/V) to cover sample slice, and setting MS acquisition parameters including polarity as positive and laser power as 70%, the MS imaging experiment was performed to analyze oligosaccharides and their distribution in soyben and soybean leaf.As a result, the MALDI-MS analysis of 3 kinds of oligosaccharides including sucrose, raffinose and stachyose was performed using the ionic liquid matrix and the reproducibility RSDs were less than 3% for in-spot and less than 4% for spot-to-spot.The standard curves linear correlation coefficients (R2) were all no less than 0.996 between MS peak intensity and oligosaccharides concentraions in the concentration rage of 0.062-1.00 mg/mL, which showed quantitative power in MALDI-MS analysis.The matrix was used for MALDI-MS imaging analysis of soybean chips and soybean leaf surface disaccharide, trisaccharide and tetrasaccharide to obtain the soybean mass spectrum and spatial resolution of 150 μm of the three oligosaccharides imaging.Three kinds of oligosaccharides in the soybean roughly balanced distribution, and the oligosaccharides distribution in the leave was mostly at its tip part.The contents of the 3 kinds of oligosaccharides could be estimated by their MS peak intensity and above standard curve.The result suggested that the ionic liquid DHB-BuN matrix could be well applied in MALDI-MS imaging analysis of oligosaccharides in different sample.
4.Potentral of plasma level of HSP70 as a biological marker of military stress
Xiujie GAO ; Xinxing WANG ; Jingbo GONG ; Yun ZHAO ; Weili LIU ; Zhusong MEI ; Can ZHANG ; Lingjia QIAN
Military Medical Sciences 2014;(3):166-168
Objective To study the possibility of the plasma level of heat shock protein 70(HSP70) being used as a bi-ological marker of military stress .Methods Soldiers who returned from a 6-month-navigation were chosen as subjects , the HSP70 level of plasma was measured with the ELISA assay and stress questionnaires and Self -rated Health Measurement Scale (SRHMS) were used to measure the stress level .Results The soldiers′plasma level of HSP70 was 31.40%higher than that of the control .The stress questionnaire indicatesd that the level of thinking and anxiety , negative mood and somat-ic symptoms were higher than normal .The SRHMS indicated that the level of physiological health ,mental health and social health was lower than normal .The plasma level of HSP70 was associated with the level of military stress .Conclusion The plasma level of HSP70 may be used as an important predictor of military stress .It can predict the level of military stress injury.
5.Construction of recombinant adenovirus vector expressing EGFP gene specifically in AFP producing liver cancer cells
Yujun SHI ; Changan LIU ; Jianping GONG ; Xuhong LI ; Yong PENG ; Ying MEI ; Can MI ; Yanying HUO
Chinese Journal of Pathophysiology 1986;0(01):-
AIM: To construct a recombinant adenovirus vector carrying AFP promoter to specifically express a targeting gene in hepatocellular carcinoma HepG2 cells. METHODS: Based on the Adeno-X~TM Expression system, the CMV promoter was replaced by a 300 bp a-fetoprotein promoter. The EGFP(enhanced green fluorescent protein) gene as a report gene was inserted to the multiple-cloning site(MCS). The normal liver LO2 cells, hepatocellular carcinoma HepG2 cells and HeLa cells were infected by the recombinant adenovirus, respectively. Northern blotting and fluorescence microscope were used to detect the transcription level of EGFP gene and its protein expression, respectively. RESULTS: Northern blotting showed that the target gene was markedly transcribed in HepG2 cells, but slightly in LO2 and HeLa cells. Under the fluorescence microscope, strong EGFP expression was seen in HepG2 cells but very weakly in HeLa and LO2 cells. CONCLUSION: Under the control of the 300 bp human AFP promoter, the target gene carried by the recombinant adenovirus was expressed in the AFP-producing HepG2 cells at a very high level, but not or very weakly in AFP negative cells. This adenovirus system can be used as a new, potent and specific approach for the gene-targeting therapy for the AFP producing primary hepatoma. [
6.Stability of akebia saponin D in gastrointestinal contents of rats.
Can-Yi GONG ; Wei XIAO ; Zhen-Zhong WANG ; Zhon-Glin YANG
China Journal of Chinese Materia Medica 2014;39(12):2311-2313
In order to study the stability of akebia saponin D (ASD) in biological fluids in vitro, the determination methods of ASD were established in this study. Akebia saponin D was dissolved in artificial gastric juice, intestinal juice and gastrointestinal contents of rats, respectively, then thermostatically maintained at 37 degrees C. At time intervals after degradation, samples were withdrawn and the concentrations of ASD were determined by HPLC, from which stability of it at different biological specimen was evaluated. As a result, ASD was totally degraded in large intestinal contents of rats in 8 hours. ASD was very stable in artificial gastric juice, intestinal juice and gastric contents of rats. All of the above data proved that ASD was easily degraded by coliform bacteria but stable in acid environment and with the presence of digestive enzyme.
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7.Preparation of oral Helicobacter pylori HpaA nucleic acid vaccine with interlukin-2 as adjuvant to prevent Helicobacter pylori infection
Can XU ; Zhao-Shen LI ; Yi-Qi DU ; Zhenxing TU ; Yanfang GONG ; Guoming XU ;
Chinese Journal of Digestion 2001;0(10):-
Objective To construct a nucleic acid vaccine expressing H.pylori HpaA and inter- leukin-2 gene and to identify the immunogenicity of the vaccine proteins in vitro and protection in vivo. Methods The H paA gene fragment was amplified by polymerase chain reaction(PCR) from the genomic DNA of the standard H.pylori strain 17874.Mouse interlukin(IL)-2 gene was amplified from pClneo- IL-2.The HpaA and IL-2 were cloned into pUCmT vector.After DNA sequences of the amplified HpaA gene and IL-2 were confirmed,both were cloned into the eukaryotic expression vector pIRES through a serial of enzyme digestion and ligation reactions.The recombinant plasmids were screened by PCR and restriction enzyme digestion.Then,recombinant pIRES-HpsA-IL-2 was transfected to COS-7 cells using Lipofectamine~(TM)2000.The immunogenicity of HpaA and IL-2 protein was detected by SDS- PAGE and Western blot.The recombinant plasmids were transformed to LB5000 and then to final host SL7207.The recombinant strains were passaged repeatedly.The mice were challenged with H.pylori after 4 weeks of inoculation of nucleic acid vaccine.H.pylori infection was detected by rapid urease test.Results The amplified HpaA gene fragment and IL-2 were confirmed by sequence analysis.The eukaryotic expression vector plRES and the pIRES-HpaA-IL-2 construction were confirmed by PCR and restriction digestion.The expressions of HpaA(30 000) and IL-2(14 000)protein by pIRES-HpaA-IL- 2 were detected by Western blot.The in vivo study showed that 75.0% and 58.4% of mice vaccinated by HpaA-IL-2 and HpaA,respectively,were protected anaigst H.pylory infection,which was signifi- cant different in comparison with PBS control (P
8.Determination of Epigoitrin in Radix Isatidis by Solid PhaseExtraction-Quantitative Nuclear Magnetic Resonance Spectroscopy
Xiaoting LIU ; Shan YU ; Ming YUAN ; Qiangsheng GUO ; Can GONG ; Xu XU
Chinese Journal of Analytical Chemistry 2017;45(7):1059-1065
The method of quantitative nuclear magnetic resonance spectroscopy (qNMR) for determination of epigoitrin in Radix Isatidis was established based on solid phase extraction (SPE).The twice ultrasonic extraction method using pure water was used for fully extracting epigoitrin in sample, and then the extraction was enriched and concentrated by poly-Sery MCX SPE cartridge.The effect of sample pretreatment and qNMR experimental conditions was investigated.The qNMR experiment conditions were selected using DMSO as solvent, calibrated 2,3,5-triiodobenzoate as internal standard, and P1(pulse width)=14.1 μs, d1(pulse delay time)=5 s, NS(number of scan)=256.The .1H-NMR peaks of δ 5.365-5.399 (H-7b, d, 1H) of epigoitrin were chosen as the quantitative peaks.Method validation was performed including precision (intra-day precision RSD was 0.5%, and the inter-day precision was 0.8%), linearity (correlation coefficient r>0.9991), LOD (0.05 mg/g, standard curve method) and LOQ (0.19 mg/g, S/N≥150).The recoveries of the SPE-qNMR were 97.4%-101.7%.The result showed that the method was stable, accurate and reliable.With this method the epigoitrin in a real Radix Isatidis was determined to be <0.19-1.26 mg/g.SPE combining with qNMR could extend the application field of qNMR, especially in the detection of low-content component in complex samples.
9.Changing of the orbital volume after endoscopic transethmoid medial wall decompression combined with the endoscopic transethmoid intraconal fat-removal orbital decompression in thyroid associated ophthalmopathy
Bo YU ; Can GONG ; Yunhai TU ; Ben CHEN ; Jieliang SHI ; Wencan WU
China Journal of Endoscopy 2016;22(12):39-44
Objective To present the changing of the parameters of orbital volume after endoscopic transethmoid medial orbital wall decompression combined with the endoscopic transethmoid intraconal fat-removal orbital decompression in thyroid associated ophthalmopathy (TAO).Methods A retrospective chart was reviewed in 11 patients (20 eyes) receiving orbital decompression for the treatment of exophthalmos secondary to TAO from September 2014 to August 2015. All patients diagnosed TAO were in stable and inactive phase at least for 6 months. High-resolution computed tomography (HRCT) scan were performed in all patients before and 3-month after surgery. CT scan of orbit and computer-aided measurement software were used to measure the exophthalmos. Changing of the parameters of orbital volume were recorded for analysis its relationship with the amount of proptosis reduction.Results The exophthalmos was signiifcantly decreased after surgery. Medial rectus volume, fat volume and orbital volume were larger postoperatively. The changing of rectus volume and fat volume both had negative correlationship with the amount of proptosis.Conclusions The thickening of medial rectus 3-month postoperative may due to the removing of medial wall of orbit during the surgery. The stimulation of the surgery may be another reason. The changing of rectus volume and fat volume both had negative correlationship with the amount of proptosis.
10.Direct Analysis of Triglycerides in Edible Oils by Atmospheric Pressure Chemical Ionization Mass Spectrometry
Yaoli ZHANG ; Xingli PEI ; Can GONG ; Yuliang HAN ; Tianqiang NI ; Fan WANG ; Shengjun WANG ; Haipeng LU ; Xu XU
Chinese Journal of Analytical Chemistry 2017;45(2):183-190
An atmospheric pressure chemical ionization mass spectrometry (APCI-MS) method was developed for the direct analysis of triglycerides in edible oils.The edible oil sample was dissolved in acetonitrile.Under the optimal conditions such as positive ion detection,800 μL/h of sample flow rate,250℃ of vaporizer temperature and 5000 nA of corona needle current,the repeatability (RSD) of peak intensity rate of m/z 857.76 to m/z 881.76 was less than 5%.Then,different kinds of oil from different manufacturers were analyzed by the proposed method.After a principal component analysis for the analytical results,the peak intensity rate of m/z 857.76 and m/z 881.76 was selected for oil identification.The adulteration of 5% lard in corn oil could be recognized directly using the peak intensity rate.Three characteristic triglycerides in edible oil were preliminarily identified by collision induced dissociation (CID) experiments.The method was applied to analyze the swill oil and fried oil samples,and the results showed that the swill oil contained both vegetable oil and animal fat,and the fried oil was also different with commercial vegetable oil.