1.Determination of ethyl pyruvate in chitosan nanoparticles by reversed-phase high-performance liquid chromatography
Fenge XU ; Bingxin ZHAO ; Shumao SUN ; Yongchun MENG ; Kaihui NAN ; Ayong YU ; Jia QU
Chinese Journal of Tissue Engineering Research 2014;(8):1205-1210
BACKGROUND:Research on ethyl pyruvate detection methods is reported rarely, and moreover, literature about reversed-phase high-performance liquid chromatography (RP-HPLC) for detection of ethyl pyruvate is less.
OBJECTIVE:To establish an RP-HPLC method for determination of ethyl pyruvate in ethyl pyruvate-chitosan nanoparticles.
METHODS: The chromatographic analysis was performed on a ZORBAX Eclipse XDB-C18 column (4.6 mm× 150 mm, 5μm) at 25℃, with the mixture of acetonitrile and water (40:60, V/V) as the mobile phase at the flow rate of 1 mL/min. The determination wavelength wasset at 210 nm and the injection volume was 20 μL.
RESULTS AND CONCLUSION: The peak of ethyl pyruvate and the peaks of auxiliary materials and solvent were separated wel. The linear rang of ethyl pyruvate was 1-100 mg/L (r=0.999 6). The relative standard deviation of both the intra-and inter-day precision was less than 3% for low-, moderate-, and high-concentration ethyl pyruvate. The relative standard deviation of reproducibility test and stability test was 1.25% and 1.3%, respectively. Sample average recovery rates were (91.5±1.0)%, (3.5±0.2)%, (94.4±0.4)%, respectively. Encapsulation efficiency of samples were (87.2±0.22)%, (90.5±0.15)%, (91.1±0.17)%, respectively. The relative standard deviation of different sample content were 0.9%, 0.5%, 0.3%, respectively. The RP-HPLC method for determination of ethyl pyruvate is sensitive, accurate and highly specific with wide linear range and high sample average recovery.
2.Collagen/bioactive glass/chitosan composite scaffolds
Yongchun MENG ; Xiaofeng CHEN ; Kaihui NAN ; Yuli LI ; Xiaogang LUO ; Chunlin DENG
Chinese Journal of Tissue Engineering Research 2014;(21):3367-3373
BACKGROUND:Col agen/bioactive glass composite materials possess excellent osteogenic potential and biocompatibility, but its application in bone tissue engineering is limited by mechanical property and degradation. OBJECTIVE:To construct col agen/bioactive glass/chitosan composite scaffolds with good mechanical property, anti-degradation ability and bone repair property.
METHODS:Bioactive glass/col agen composite scaffolds with chitosan as dispersant were prepared by lyophylization. Fourier transform infrared spectroscopy, scanning electron microscope, X-ray diffraction, and dynamic biomechanical testing were used to characterize the structure and properties of the composite scaffolds. RESULTS AND CONCLUSION:Results show that charge-attractions in pre-prepared bioactive glass/chitosan solution increased the homogeneity of bioactive glass dispersed in col agen gel and the compressive modulus and strength increased significantly due to the homogeneity and intermolecular interactions between chitosan and col agen. The enzymatic degradation rate and mineralization activity in the simulated body fluid were also lower because of a high degree of embedment of bioactive glass in col agen/chitosan matrix, and entanglement of col agen in chitosan at molecular level, which decreased the exposure of bioactive glass to the simulated body fluid, and col agen to enzyme solution.
3.Investigation on mechanical property of the compound scaffold of Sol-Gel bioactive glass/collegan
Juanjuan ZHANG ; Yongchun MENG ; Xiaofeng CHEN ; Yuli LI ; Xiaogang LUO ; Cai LIN
Journal of Medical Biomechanics 2010;25(1):16-20,25
Objective To investigate the mechanical prosperity and degradation rate of the scaffolds with compounding collagen and the nano sol-gel derived bioactive glass were studied,and provide the theoretical basis for the further application of collagen based scaffolds.Method The scaffold with compounding collagen and the nano sol-gel derived bioactive glass(58S)were prepared using the freeze-drying techniques with the bioactive glass as phase addition.By affecting the aggregation state of the collagen fibers with adjusting the supplementation of bioactive glass to change the microstructures of the compound scaffolds and finatly the compound scaffolds with different mechanical properties were prepared.Results (1)As the aggregation state of the collagen fibers changes,the scaffolds with the coarser collagen fibers is prepared with the diameters 400-600 nm approximately.The coarser collagen fibers will play an important role in improving the mechanical property and slowing down the degradation rate of the collagen based scaffolds.(2)The interactions between bioactive glass and collagen are studied by FTIR and Raman technologies.When the quality of content of collagen in the compound scaffolds is lower than 20%,the secondary structure of collagen is damaged severely.Conclusion The composite scaffolds with the mass ratio of collagen to bioactive glass 40:60 has the best performance in mechanical property and degradation,which will be helpful for further applications.
4.Characterization and subcellular localization of two 14-3-3 genes and their response to abiotic stress in wheat.
Xiaodan MENG ; Xin CHEN ; Yaying WANG ; Ruixia XIAO ; Hailun LIU ; Xinguo WANG ; Jiangping REN ; Yongchun LI ; Hongbin NIU ; Xiang WANG ; Jun YIN
Chinese Journal of Biotechnology 2014;30(2):232-246
In order to investigate biological functions of the 14-3-3 genes and their response to abiotic stress, two cDNAs (designated as Ta14R1 and Ta14R2) encoding putative 14-3-3 proteins were isolated from wheat by PCR and rapid amplification of cDNA end (RACE) technique. The cDNA of Ta14R1 is 999bp and encodes a protein of 262 amino acids, while the cDNA of Ta14R2 is 897bp in length and encodes a protein of 261 amino acids. Transient expression assays using Ta14R1/Ta14R2-GFP fusion constructs indicated that Ta14R1 and Ta14R2 were located in cytoplasm and cell membrane but not in chloroplasts. Real-time quantitative (RT-PCR) analysis revealed that Ta14R1 and Ta14R2 were differentially expressed in wheat tissues and significantly up-regulated in roots and shoots 1d after germination, indicating they may play a role in process of seed germination. The expression of the two genes in roots and leaves were significantly induced by plant hormone ABA, as well as heat, cold and drought treatments, suggesting that the two 14-3-3 genes in wheat may be involved in ABA dependent stress-responding pathway and response to heat, cold and drought stress.
14-3-3 Proteins
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genetics
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Abscisic Acid
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pharmacology
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DNA, Complementary
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Droughts
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Gene Expression Regulation, Plant
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Genes, Plant
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Germination
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Plant Leaves
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genetics
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physiology
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Plant Roots
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genetics
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physiology
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Stress, Physiological
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Temperature
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Triticum
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genetics
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physiology
5.Spatiotemporal expression patterns of three vernalization genes in wheat.
Xiuyun YUAN ; Yongchun LI ; Fanrong MENG ; Xiao WANG ; Jun YIN
Chinese Journal of Biotechnology 2010;26(11):1539-1545
To identify spatiotemporal expression patterns of vernalization genes in common wheat, we analyzed expression characteristics of several vernalization genes (VRN1, VRN2 and VRN3) in the wheat cultivars 'Chinese spring' and 'Luohan 2' by RT-PCR. The VRN1 gene was expressed at different levels in the leaves and roots at the 3-leaf stage, stems, flag leaves at the grain-filling stage, anthers, ovules, and developing seeds in 'Chinese spring'. Expression of VRN1 increased before flowering date, then decreased after flowering time. Expression of VRN1 was not detected in dry seeds or seeds germination. Expression patterns of VRN1 in 'Luohan 2' were similar to those in 'Chinese spring', except that it was not expressed in roots or in the leaves at the 3-leaf stage in 'Luohan 2'. Expression of VRN2 was only detected in the leaves at the 3-leaf stage and in the embryo buds during seeds germination. The Spatiotemporal expression of VRN3 was similar to that of VRN1, except that VRN3 was not expressed in roots. These results improved our understanding of the molecular regulation of vernalization genes in common wheat.
Flowers
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genetics
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physiology
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Gene Expression Regulation, Plant
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genetics
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Genes, Plant
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genetics
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Triticum
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genetics
6.Hyper-early embolotherapy in treatment of intracranial ruptured aneurysm
Yiping LI ; Yongchun LUO ; Zijun HE ; Chunsen SHEN ; Jinlong MAO ; Jingshan MENG ; Chuntao YUAN ; Shang MA ; Qiang ZHANG ; Chunyang LIANG ; Ruxiang XU
Chinese Journal of Postgraduates of Medicine 2013;(2):9-11
Objective To explore the clinical efficacy and safety of hyper-early embolotherapy in treatment of intracranial ruptured aneurysm.Methods A retrospective analysis was made on 33 patients with intracranial ruptured aneurysm.Preoperative Hunt-Hess grade:grade Ⅰ-Ⅱ in 16 patients,gradeⅢin 5 patients,grade Ⅳ in 9 patients,grade Ⅴ in 3 patients.All patients were confirmed with subarachnoid hemorrhage (SAH) by angiography and then underwent embolization under general anesthesia by detachable coils within 6 h from onset.Results After operation,25 patients (75.8%) recovered well,4 patients (12.1%) were with mild disability with paralysis and aphasia,4 patients (12.1%) were dead (1 patient for intraoperative aneurysm rupture,1 patient for postoperative pneumonia,1 patient for infection of hematoma at puncture site and 1 patient for postoperative gastrointestinal bleeding).Followed up 1-6 months,no rebleeding occurred.Conclusions Hyper-early embolotherapy could avoid rebleeding of the aneurysm,and relieve the vasespasm,without increasing the intra-operative rebleeding rate.Moreover hyper-early embolotherapy could greatly decrease the mortality of poor-grade SAH patients.
7.Application of tracing technique of labeling bone marrow mesenchymal stem cells with green fluorescent protein in tissue-engineered bone construction in vitro.
Caixia XU ; Peng XIANG ; Rui CHEN ; Yingjun WANG ; Xiaofeng CHEN ; Yongchun MENG ; Chang LIU
Journal of Biomedical Engineering 2011;28(1):121-137
This study was designed to label rat bone marrow mesenchymal stem cells (rBMSCs) with humanized renillar green fluorescent protein (hrGFP) for exploring the detectable effects of hrGFP on the construction of tissue-engineered bone in vitro. The hrGFP expression plasmid was packed into lentivirus by 293FT cells and transduced into rat BMSCs. After transduction, 81.3% rBMSCs successfully expressed green fluorescence. The hrGFP-rBMSCs were statically loaded on Bioglass-Collagen-Hyaluronic Acid-Phosphatidylserine (BG-COL-HYA-PS) scaffold in complete L-DMEM medium or osteogenic medium for 14 days. At 6h, a number of cells expressing green fluorescence can be observed by fluorescent microscopy. At day 7 and 14 after co-culture, the number of cells on the scaffold gradually increased. After 14 days for osteogenic induction, the hrGFP-rBMSCs and the interior of scaffold can be detected the expression of type I collagen. The results demonstrate that hrGFP labelling technique can detect visualizedly and effectively cell adhesion, proliferation and osteogenic differentiation in the construction of tissue-engineered bone in vitro.
Animals
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Bone Marrow Cells
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cytology
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Cell Culture Techniques
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Cells, Cultured
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Green Fluorescent Proteins
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genetics
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metabolism
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Humans
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Mesenchymal Stromal Cells
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cytology
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metabolism
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Osteogenesis
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Rats
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Staining and Labeling
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methods
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Tissue Engineering
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methods
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Tissue Scaffolds
8.Adipose-derived mesenchymal stem cell-derived exosomes alleviate hydrogen peroxide-induced PC12 cell apoptosis
Chengxu GU ; Naili ZHANG ; Yongchun MENG ; Qing LIU ; Qixuan GUO ; Li FU ; Luping ZHANG ; Fei HUANG
Chinese Journal of Tissue Engineering Research 2024;28(19):2988-2995
BACKGROUND:Mesenchymal stem cell-derived exosomes may play a crucial role in tissue damage repair,and miRNA is an important component of exosomes for therapeutic effects.Among them,miR-29b-3p has the effect of reducing cell apoptosis,promoting axonal regeneration,and angiogenesis. OBJECTIVE:To study the protective effect of adipose-derived mesenchymal stem cell-derived exosome via miR-29b-3p on a neural cell injury model simulated by H2O2-treated PC12 cells,and explore the relevant mechanisms. METHODS:(1)First,the collagenase digestion method was used to extract rat adipose-derived mesenchymal stem cells.Adipose-derived mesenchymal stem cells were transfected with miR-29b-3p mimics and inhibitors.Exosomes were extracted from the culture supernatant by ultracentrifugation and identified so as to construct adipose-derived mesenchymal stem cell-derived exosomes with high expression and knockdown miR-29b-3p.(2)By constructing a neural cell injury model simulated by PC12 cells treated with H2O2,the relevant mechanisms of the protective effect of adipose-derived mesenchymal stem cell-derived exosome via miR-29b-3p on the simulated neuronal cell injury model were studied. RESULTS AND CONCLUSION:(1)Adipose-derived mesenchymal stem cell-derived exosome had a typical cup-shaped shape and a diameter distribution in the range of 50-140 nm,expressed membrane proteins Alix,CD63,and TSG101,which were specific markers on the surface of exosomes,and could be successfully ingested by PC12 cells.(2)Adipose-derived mesenchymal stem cell-derived exosome pretreatment could reduce cell apoptosis induced by H2O2 treatment in PC12 cells,and this protective effect was enhanced with the increase of miR-29b-3p expression in the exosomes and weakened with the decrease of miR-29b-3p expression in the exosomes.The mechanism of its effect was related to adipose-derived mesenchymal stem cell-derived exosome via miR-29b-3p promoting the expression of anti-apoptotic protein Bcl-2 and inhibiting the expression of apoptotic protein Bax.
9.Mining and evaluation of relugolix-related cardiovascular safety signals
Yongchun LIN ; Long MENG ; Jiajun ZHENG ; Huiming JIANG
China Pharmacy 2024;35(18):2278-2282
OBJECTIVE To mine the cardiovascular safety signal of relugolix, and provide a reference for the listing of this drug in China and future clinical safety drug evaluation. METHODS The adverse event (AE) report data of relugolix, as the primary or secondary suspected drug, was collected from the FDA Adverse Event Reporting System (FAERS) from the first quarter of 2021 to the third quarter of 2023. The reporting odds ratio (ROR) method was used for data mining. The AEs in the FAERS database were identified and coded using preferred terms (PT) stated in version 24.0 of the Medical Dictionary for Drug Regulatory Activities (MedDRA). The AEs of the target drug were identified by the narrow standardized MedDRA query (SMQ) terms and high-level term (HLT). Sensitivity analysis was conducted using AEs suspected to be primarily or secondarily related to relugolix or related to drug interaction and concomitant drug, and broad SMQ terms. RESULTS A total of 4 354 relugolix-related AE reports were extracted. In the primary analysis, nine SMQ terms were analyzed, involving 2 positive signals such as dyslipidemia and hyperglycemia/new onset diabetes mellitus. Eleven HLTs were analyzed, and three positive signals were detected for three terms including cholesterol analyses, triglyceride analyses and hyperglycemia conditions (non-alternative analysis). Sensitivity analysis results indicated the reliability of the study findings. CONCLUSIONS Relugolix may induce risk signals related to high blood lipids and high blood glucose, but no moderate risk signals such as hypertension, heart disease, and stroke are found. During relugolix treatment in clinical practice, attention must be paid to hyperlipidemia and hyperglycemia-related AE.
10.Analysis of clinical and laboratory features of 217 pediatric hemophagocytic lymphohistiocytosis.
Li XIAO ; Xianmin GUAN ; Yan MENG ; Yongchun SU ; Ying XIAN ; Jianwen XIAO ; Yinghui CUI ; Jie YU
Chinese Journal of Hematology 2014;35(7):628-632
OBJECTIVETo investigate the incidence, clinical symptoms, signs and laboratory features of childhood hemophagocytic lymphohistiocytosis (HLH) in China.
METHODSA retrospective study was performed on 217 pediatric patients with HLH who were admitted to Children's Hospital of Chongqing Medical University from January 2006 to April 2013. All patients'medical records were reviewed and analyzed.
RESULTSThe Male to female ratio was 1.11:1. The median onset age was 3 years and 5 months old (range of 6 months old to 16 years and 9 months old), and the age of onset peaked between 1-5 years old (61.3%). The most common causes of HLH was infection, especially Epstein-Barr virus-associated HLH (71.0%). Other causes included malignant hemophagocytic syndrome (MAHS), macrophage activation syndrome (MAS) and so on. The outstanding clinical manifestations including persistent fever (100.0%), hepatomegaly (92.6%), splenomegaly (88.4%), and more than half of cases with central nervous system involvement and pulmonary manifestations. Laboratory data indicated that the most prominent abnormality was elevated ferritin (98.0%), and the others were hemophagocytosis in bone marrow (90.7%) and coagulation abnormalities (76.5%). Abnormal lymphocytes classification is very common in HLH.
CONCLUSIONHLH is a heterogeneous disease, with a variety of the etiology and clinical manifestations. HLH-2004 diagnostic protocol had theoretical basis and clinical operability. The hepatitis damages related indicators, lymphocytes classification, central nervous system involvement and pulmonary performance can be used as reference value for HLH diagnosis.
Adolescent ; Child ; Child, Preschool ; Female ; Humans ; Infant ; Lymphohistiocytosis, Hemophagocytic ; diagnosis ; Male ; Retrospective Studies