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ObjectiveTo construct 131Ⅰ-labeled hepatoma nucleic acid nanotrain and to explore its feasibility as a new nuclide carrier targeting hepatoma. MethodsThree short nucleic acid chains self-assembled to a long nucleic acid chain after being annealed， and 131Ⅰ-NT was obtained by radioiodine labeling using chloramine T method. The labeling efficiency and radiochemical purity of the nanoparticles were measured by paper chromatography. The stability of the labeled products in vitro at different temperatures and different storage solvents was detected. The specific uptake of nanoparticles by hepatocellular carcinoma cells was observed by laser confocal microscopy， and the radioactive uptake ratio of 131Ⅰ-NT combined with human hepatocellular carcinoma cell HepG2 and normal hepatocyte L02 was measured. The biodistribution of 131Ⅰ-NT was obtained through injecting 131Ⅰ-NT into HepG2 tumor-bearing mice via tail vein. ResultsThe labeling rate of 131Ⅰ-NT was （93.05±0.74） %， and the radiochemical purity post purification was （98.35±0.32） %. Its radiochemical purity in PBS and pure serum at 4℃ for 24 h was （92.77±0.04） % and （89.43±0.2） %， respectively. The radioactivity uptake rate of HepG2 cells was higher than that of L02 cells after 131Ⅰ-NT was incubated with two kinds of cells for 2 h significantly. After injection of 131Ⅰ-NT through tail vein， the radioactive uptake per gram of tumor tissue were （4.9±0.55）%ID/g， （10.12±0.32）%ID/g and （4.25±0.31）%ID/g at 30 min， 1 h and 2 h， respectively. The T/M ratio was 7.33±2.04， 36.54±12.72 and 44.93±7.90 respectively. ConclusionsThe 131Ⅰ-labeled long chain nucleic acid nanotrain was constructed successfully， which possesses relatively high stability in vitro ， and high targeting ability to HepG2 cells in vitro and HepG2 tumor-bearing mouse model. Our study demonstrated that 131Ⅰ-NT may be a potential radionuclide carrier targeting human liver cancer， which provides a new idea for the targeted radionuclide diagnosis and treatment of hepatocellular carcinoma.
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@#【Objective】To explore the role of lncRNA Xist in proliferation and migration of rat bone marrow mesenchymal stem cells（BMSC）and its possible mechanism.【Methods】BMSC were isolated，cultured and identified from the femur and tibia of 3 weeks old SD female rats in vitro. SiRNAs was designed and screened to acquire a high silencing efficiency siRNA. Lipo2000 was used to transfected si- Xist and si- NC into BMSC of the experimental group（si- Xist group）and the control group（si-NC group）. BMSC proliferation capacity was determined by CCK-8 assay. The transverse and longitudinal mobility of BMSC were measured by wound healing assay and transwell migration assays. QPCR was performed to verify the silencing efficiency of lncRNA Xist and detect the expression levels of SDF- 1 and CXCR4 mRNA. Western blot was used to quantify the expression of CXCR4 protein.【Results】The P3 generation BMSC shows shuttle- like or whirlpool-like，and flow cytometry showed CD11b（-），CD34（-），CD45（-），CD44（+），CD90（+），CD105（+）. When siRNAs were used to interfere with the expression of lncRNA Xist in BMSC ，the silencing efficiency of three siRNAs was 67.92% ，68.72% and 98.32% ，respectively. CCK- 8 assay showed that the OD450 value of si- Xist group decreased compared with si-NC group at 24 h and 48 h（P < 0.001，P < 0.01，respectively）and had no statistical difference at 12 h（P > 0.05）. Wound healing assay showed that the wound healing percentage of si-Xist group was lower than that of si-NC group（P < 0.05）；and the transwell migration assay showed that，compared with si- NC group，the cells that migrated through the polycarbonate membrane were obviously decreased at 6 h（P < 0.001）. QPCR experiment showed that CXCR4 expression in si-Xist group was lower than that in si-NC group at mRNA level（P < 0.05），while SDF-1 expression showed no significant statistical difference（P > 0.05）. Western blotting confirmed that CXCR4 expression in si- Xist group was lower than that in si-NC group（P < 0.05）.【Conclusions】LncRNA Xist promotes proliferation and migration of rat BMSC by regulating CXCR4 expression.
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Objective To investigate current situation of Chinese clinical microbiological laboratories participating in management of healthcare-associated infection and antimicrobial use.Methods Fourteen provinces (municipalities), autonomous regions and army hospitals in seven regions of China were selected, the participation of clinical microbiological laboratories in the consultation of HAI diseases, specimen quality control, antimicrobial use, and management of multidrug-resistant organisms (MDROs) before 2000 and every five years from 2000 to 2015 were investigated, the surveyed results were analyzed statistically.Results A total of 187 hospitals were investigated, in 2015, 96 and 172 hospitals (51.34％, 91.98％) participated in the consultation of infectious diseases and multi-department collaborative management on MDROs respectively.However, 44 hospitals (23.53％) still manually performed statistical analysis on drug susceptibility, only 26 hospitals (13.90％) had the ability of identifying homology of pathogens.Rate of MDRO surveillance data feedbacked to clinical departments increased from 66.84％ (n=125) in 2010 to 95.72％ (n=179) in 2015, the frequency of feedback was mainly monthly and quarterly;rate of antimicrobial susceptibility results feedbacked to clinic departments increased from 62.03％ (n=116) to 94.12％ (n=176), 82.35％ (n=154) of clinical microbiological laboratories conducted quarterly feedback;the quality control rate of microscopic sputum smear before sputum culture increased from63.10％ (n=118) to 87.17％ (n=163);rate of bilateral double blood culture increased from 35.83％ (n=67) to 72.73％ (n=136);rates of other aseptic body fluid culture (except blood and urine) increased from 4.86％ to 5.74％;differences were all significantly different between 2010 and 2015 (all P＜0.05).Conclusion Clinical microbiological laboratories have played an important role in promoting the development of HAI management in China, especially during the period of 2011-2015.However, the homology analysis on HAI pathogens, informatization of result feedback, and sterile body fluid specimens detection need to be further strengthened.