Objective:To investigate the preparation of paclitaxel-loaded nanoparticles targeting liver cancer stem cells and their effects on liver cancer HepG2 cells (CD133 positive subset accounting for 8%) and Huh-7 cells (CD133 positive subset accounting for 65%).Methods:Poly (lactic-co-glycolic acid)-loaded paclitaxel nanoparticles were prepared by using emulsification-solvent evaporation method. Paclitaxel-loaded nanoparticles decorated with anti-CD133 antibody, called targeted nanoparticles, were prepared by using 1- (3-dimethylaminopropyl)-3-ethylcarbodiimide/N-hydroxysuccinimide (EDC/NHS) cross-linking method. The manifestations and physicochemical characteristics of the nanoparticles including encapsulation efficiency, loading efficiency, particle size distribution, morphology and release in vitro were studied. Liver cancer Huh-7 and HepG2 cells accompanying with paclitaxel-loaded nanoparticles or targeted nanoparticles were cocultured. The uptake and accumulation of nanoparticles by liver cancer cells were analyzed by using flow cytometry, and positive cell proportion of CD133 was also detected. Cell survival was analyzed by using plate clonogenesis assay.Results:Scan electromicroscopy result showed particle size of targeted nanoparticles was (429.26±41.53) nm with zeta potential of -11.2 mV; targeted nanoparticles were possessed with spherical morphology and higher encapsulation efficiency [(87.53±5.90) %]. Flow cytometry showed that in Huh-7 cells at 37℃, the fluorescence intensity of targeted nanoparticles group (13 397±720) was higher than that of paclitaxel-loaded nanoparticles group (6 898±604), and the difference was statistically significant ( P < 0.05); there was no statistically difference in the fluorescence intensity of HepG2 cells in paclitaxel-loaded nanoparticles group and targeted nanoparticles group at 37 ℃ (7 899±343 vs. 8 432±516, P>0.05). CD133 positive cell proportion of Huh-7 cells in targeted nanoparticles group [(15.7±2.6)%] was lower than that in paclitaxel-loaded nanoparticles group [(54.9±7.4)%], and the difference was statistically significant ( t = 7.31, P = 0.008); there was no statistical difference of HepG2 cells between the two goups ( P > 0.05). Plate clonogenesis assay showed that the cell survival rate of Huh-7 cells in targeted nanoparticles group was lower than that in paclitaxel-loaded nanoparticles group at different time points, and the difference was statistically significant ( F = 5.56, P = 0.009); but there was no statistically significant difference in HepG2 cell survival rate between the two groups ( F = 1. 19, P = 0.142). Conclusion:Prepared nanoparticles targeting liver cancer stem cells have a good inhibitory effect on liver cancer Huh-7 cells.

Adolescent ; Gene Rearrangement ; Humans ; Leukemia, Myeloid, Acute ; etiology ; genetics ; Male ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; complications ; genetics ; Receptor, Platelet-Derived Growth Factor beta ; genetics

AIM　To investigate the effects of ginkgolide B on arachidonic acid (AA) metabolizing enzymes and the level of intracellular calcium in rat polymorphonuclear leukocytes. METHODS　Intracellular free calcium was quantitated by Fura-2 fluoresence technique. Phospholipase A2 (PLA2) activity was determined by incorporating 3H-arachidonic acid in leukocytes. 5-Lipoxygenase (5-LO) activity was evaluated by RP-HPLC. RESULTS　In comparison with control, ginkgolide B at final concentration of 0.1-10 μmol*L-1 inhibited A23187 induced AA release by 10.9%-22.2%; at final concentration of 0.1-50 μmol*L-1, ginkgolide B inhibited LTB4 and 5-HETE synthesis stimulated by PAF by 29.4%-88.8% and 26.2%-89.3% respectively. At the final concentration of 0.1-100 μmol*L-1, ginkgolide B decreased the rise of intracelluar calcium level induced by pletelet activating factor (PAF) and N-formyl-methionine-leucine-phenglalanine (fMLP) by 13.9%-51.4% and 2.2%-36.6%, respectively. CONCLUSION　Ginkgolide B was found to significantly inhibit PLA2 and 5-LO activities, as well as the increase of the intracellular calcium induced by PAF.

Objective: To construct the eukaryotic expression vector pSurp-EGFP regulated by the survivin gene promoter and to detect the specific expression of the promoter in human laryngeal cancer Hep-2 cells by green fluorescent protein assay.Methods: Thesurvivin gene promoter was generated by polymerase chain reaction(PCR) and the CMV promoter of the pShuttle vector replaced by the survivin gene promoter to generate the plasmid pSurp.The three plasmids pShuttle,pSurp and pEGFP-C1 were respectively double-enzyme digested so as to produce the plasmids pCMV-EGFP and pSurp-EGFP carrying the CMV or survivin promoter.The purified pCMV-EGFP and pSurp-EGFP were transfected into Hep-2 cell and vascular endothelial cell ECV304 using liposome transfection reagent and the expressions of EGFP detected by the fluorescent microscope.Results: Thesurvivin gene promoter was successfully cloned by PCR,and thesurvivin gene promoter-regulated pSurp-EGFP was constructed.Green fluorescence was observed in Hep-2 cells but not in ECV304. Conclusion: The high specific activity of the survivin gene promoter in Hep-2 cells that we successfully constructed attributes to the studies of tumor specific gene therapy.

Objective To investigate MR findings and analysis of misdiagnosis of atypical invasive pituitary adenoma.Methods The MR findings of twenty cases of atypical invasive pituity adenomas confirmed by pathology were reviewed ,which were misdiag-nosed as chordomas or meningiomas.Results All the twenty cases showed iso-or slightly hypo-signal on T1 WI,iso-or slightly hy-per-signal on T2 WI;Enhanced scan displayed heterogeneous enhancement.The dynamic enhancement curve showed rapid enhance-ment phase.The bilateral cavernous sinuswere infringed in nine cases,in which the pituity and pituity stalk were not well seen. Among the twenty cases,twelve cases with suprasellar and anterior cranial fossa extension were misdiagnosed as meningiomas;eight cases with clival destruction were misdiagnosed as chordomas.Conclusion The MR features of atypical invasive pituity adenomas are various.In order to avoid misdiagnosis,a comprehensive analysis should be based on a variety of signs.

Objective To investigate the significance and expression of PTEN, MLL in T lymphoblastic lymphoma/leukaemia(T-LBL/ALL). Methods Seventy-six cases of T-LBL/ALL were studied by using immunohistochemical EnVision method for PTEN. Fluorescence in-situ hybridization (FISH) for MLL gene (located on chromosome 11q23) was performed to detect its breakage and amplification. Results Among the 76 cases ofT- LBL/ALL, the positive rate of PTEN was 64.47 % (49/76), lower than that in reactivated lymphoid tissue (100 %, 20/20) (λ2= 19.220, P ＜0.05). PTEN expression was reversely correlated to theclinical stage, Ki-67 index and LDH level (P ＜0.05). Among the 76 cases, MLL gene with breakage of 11q23 was detected in 13 cases (17.11%), and amplification in 18 cases (23.68 %). Survival rate ot MLL gene breakage group was lower than that of non-breakage group (25.0 %, 43.6 %). Survival rate of MLL gene amplification group was lower than that of non-amplification group too (17.1%, 42.7 %). Both of breakage and amplification were related to prognosis ( λ 2 = 11.357, λ 2 = 4.533; P ＜0.05). Conclusion Anti-oncogene PTEN down-regulation may play an important role on the development and proceeding of T-LBL/ALL. MLL gene with breakage and amplification of 11q23 are helpful to predict prognosis of T-LBL/ALL. The case with MLL gene breakage and amplification of T-LBL/ALL may have a poor prognosis. It hints this group maybe a subtype of T-LBL/ALL.

Objective To establish a radioresistant esophageal squamous cancer cell line,and to identify the radioresistant genes and mechanisms.Methods The radioresistant KYSE410-res cell line was established by repeated exposure of cell line KYSE410 to radiation.The proliferation and apoptosis of esophageal squamous cancer cells were evaluated before and after radiation.The changes in gene expression of the esophageal squamous cancer cells after radiation were determined by gene microarray and analyzed by group t test.The genes with significant difference in expression after radiation were validated.Results The KYSE410-res cells had significantly enhanced proliferation and anti-apoptosis than the KYSE410 cells (all P＜0.05).The result of gene microarray showed that compared with the KYSE410 cells,the KYSE410-res cells had the expression of 463 and 251 genes upregulated and downregulated by no less than 4 folds,respectively.Those genes with different expression levels after radiation were mainly responsible for cell proliferation,adhesion,signal transduction,angiogenesis,reactive oxygen metabolism,cell damage repair,and the MAPK/ERK signaling pathway.OAS2 and UBD were key proteins in the network.In the KYSE410-res cells,the expression of HLA-DQBI,MMP1,NCAM1,ZNF521,GPC6,SELENBP1,LCN15,and TFPI-2 genes measured by real-time PCR was consistent with that measured by gene microarray.Conclusions Abnormal activation of the MAPK/ERK signaling pathway,upregulated expression of OAS2 and UBD,downregulated expression of TFPI-2,and upregulated expression of MMPs may play a role in radioresistance of esophageal cancer cells.

Objective To investigate the role of cancer stem cells in radiation resistance of esophageal cancer and its molecular mechanism, and to provide a theoretical basis for radiotherapy for esophageal cancer.Methods Esophageal cancer cell line TE1 was treated with 8 Gy of radiation. Esophageal cancer cell line with resistance to radiation, TE1-res, was established and screened.Cell counting was used to evaluate cell proliferation.Flow cytometry was used to determine the expression of CD44 (high) CD24(-) CD133(+) and apoptosis in cells.The colony formation assay was used to determine the colony-forming rate and cell survival curve.Bisulfite sequencing PCR was used to determine the methylation status of cancer suppressor genes.Comparison of the data was made by group t test or analysis of variance. Results Compared with TE1 cells, TE1-res cells had significantly enhanced proliferation, a significantly higher proportion of CD44( high) CD24(-) CD133(+) cells, and significantly enhanced resistance to apoptosis (mean value 20.84×105 vs.4.46×105/day, P=0.008;(38.0±2.9)%vs.(10.1±1.3)%, P=0.001;mean value 33.23% vs.10.50%, P=0.003 ) .After treatment with 8 Gy of radiation, TE1-res cells had significantly higher colony-forming rate and D0 value than TE1 cells ((14.3±2.6)%vs.(0.9±0.3)%, P=0.011;3.28 vs.2.19 Gy, P=0.125 ) .Moreover, the promoter methylation in cancer suppressor genes including SPINT2, CDKN1B, DKK1, TP53, and PPP2R1B was significantly enhanced in TE1-res cells than in TE1 cells ((89.7±4.9)%vs.(5.0±0.5)%, P=0.001;(92.3±4.7)%vs.(10.4±0.7)%, P=0.001;(90.7±3.7)%vs.(7.9±0.4)%, P=0.001;(83.4±5.7)%vs.(17.2±1.2)%, P=0.002;(90.2±
6.7)%vs.(4.4±1.2)%, P=0.002).Conclusions Cancer stem cells play an important role in radiation resistance of esophageal cancer. The resistance to radiation is closely associated with promoter hypermethylation in cancer suppressor genes including SPINT2, CDKN1B, DKK1, TP53, and PPP2R1B.

By establishing a series of Dynamic Cervical Implants (DCI) within C5-C6 cervical spinal segments, the biomechanical finite element analysis for DCI with different width and thickness were carried out to investigate the influence of the width and thickness of DCI's curved section on its equivalent stress and range of motion (ROM), so as to provide some theoretical basis for the optimization of DCI's design. The results show that the width of DCI's curved section has more obvious influence on the ROM of lateral bending and torsion, in comparison with the thickness of DCI's curved section. By appropriate reduction in width, the ROMs of lateral bending and torsion increase obviously, i.e. the overall movement function of patients is improved. Furthermore, the increase of equivalent stress could be counteracted by corresponding increase of thickness.
Biomechanical Phenomena ; Cervical Vertebrae ; Finite Element Analysis ; Humans ; Movement ; Neck ; Prostheses and Implants ; Prosthesis Design ; Range of Motion, Articular

Setting up the chief teacher to be fully responsible for the medical course teaching is an explorative idea.It is necessary for the construction of medical teachers,integration of medicine courses and capacity building of young teachers.A qualified chief teacher should be a professional teacher with enough academic prestige and some management experience.Chief teachers will play important roles in the overall course teaching process,including organizing the teaching team,developing the objectives,plans,guidelines of the course and supervising the execution teaching program.The author also propose that the chief teacher responsibility system should be put into the medical course teaching practice which will improve the course teaching quality and make contributions to training excellent medical personnel.