OBJECTIVE To investigate the effect and mechanism of low concentrations of p,p′-dichlorodiphenyltrichloroethane (p,p′-DDT) on colorectal adenocarcinoma SW620 cell proliferation and apoptosis. METHODS SW620 cells were exposed to low concentrations of p, p′-DDT ranging from 1×10-12 to 1×10-6 mol.L-1 for 48 and 96 h. MTT assay was employed to examine the effect of p,p′-DDT on SW620 cell viability. Different cell stages of cycle and apoptosis rate were determined by flow cytometry after SW620 cells were exposed to 1×10-10 , 1×10-9 and 1×10-8 mol.L-1 for 96 h. Western blotting was used to determine the protein expression of Wnt/ β-catenin signaling components 〔β-catenin, phospho-β-catenin and phospho-glycogen synthase kinase ( GSK) 3β〕, their downstream target proteins ( c-Myc and cyclin D1)and apoptosis related proteins (Bcl-2, Bax, procaspase 8 and procaspase 3). RESULTS The viability of colorectal adenocarcinoma SW620 cells was significantly increased after exposure to low concentrations of p,p′-DDT ranging from 1×10-12 to 1×10-7 mol.L-1 for 96 h. p,p′-DDT 1×10-10 , 1×10-9 and 1×10-8 mol.L-1 exposure led to a decreased percentage of SW620 cells in G1 stage(P<0.01) along with an increased percentage of cells in S stage(P<0.01). Meanwhile, the apoptosis rate was signifi-cantly decreased compared with control group ( P < 0. 01). Exposure to p, p′-DDT from 1 × 10-10 to 1×10-8 mol.L-1 induced upregulation of phospho-GSK3β ( Ser9), β-catenin, c-Myc and cyclin D1 in SW620 cells( P <0.01). Moreover, apoptosis related proteins Bcl-2, procaspase 8 and procaspase 3 were unregulated(P<0.01), and Bax level and caspase 3 activity were decreased in p,p′-DDT-stimulated cells(P < 0.01). CONCLUSION Low concentrations of p, p′-DDT exposure activates Wnt/ β-catenin signaling and affects apoptosis-related proteins, which may be involved in p,p′-DDT-induced cell prolifer-ation as well as suppression of cell apoptosis in SW620 cells.

OBJECTIVE To investigate the feasibility and application of enzyme-linked bridging assay(ELBA)method to the pharmacokinetic evaluation of antisense strand siRNA drug. METHODS Antisense strand RNAs were diluted in LNCap cell lysates from 5 to 50 000 pmol·L-1 to construct the quantification curves. We transfected the intact double-strand siRNA at a final concentration 100 nmol·L-1 targeting Polo-like kinase into the LNCap cells and investigated the specificity of ELBA quantitating the siRNA antisense strand in cell supernatant,cell lysates and RNA-induced silencing complex( RlSC). Quantification curves were constructed and validated in biological matrices such as plasma (5-25 000 pmol·L-1 )and multiple tissues(liver,heart,spleen,and kidneys)(3-6250 pmol·L-1 ). The prostate specific membrane antigen aptamer siRNA delivery system with the intact siRNA concentration of 15 nmol·kg-1 was prepared. The siRNAs were delivered into the LNCap xenogrant tumor model in C57 mice by tail vein injection. The concentration of siRNA antisense strand was determined in plasma and tissues 30 min post administration by ELBA. RESULTS The quantitative range of antisense strand siRNA in cell lysates was 5-50 000 pmol·L-1 ,and ELBA method could quantify the siRNA antisense strand concentration from cell lysates and RlSC in LNCap cells transfected with double-strand siRNA. ln addition,ELBA could specifically reflect the single antisense strand concentration instead of intact siRNA double strands in plasma. The quantification range of siRNA antisense strand using ELBA in plasma was 5-25 000 pmol·L-1 and 3-3125 pmol·L-1 in tissues. About 30 min post administration of PSMA aptamer-siRNA,the antisense strand of siRNA was distributed mainly to the tumor,liver,kidneys,blood and spleen in sequence. The distribution profile might be attributed to the target delivery and siRNA pharma-codynamics. CONCLUSION The ELBA method is successfully applied to the siRNA antisense strand pharmacokinetic evaluation,which provides an alternative for pharmacokinetic studies of siRNA-based drugs.

Teachers are the most important resources of colleges and univesities. Setting up the teachers' competence model of medical colleges and universities is the basis of guaranting the quality of medical education, which accords with the need of the post training of teachers and can be the basis for teachers' competence assessment.

The cause of so-called lumbar disc syndrome are multiple and each cause must be throughly and carefully investigated. The proper treatment may not be successful if one of these factors is ignored. Forty patients with lumbar disc syndrome were examined with a third generation CT scanner(Somatom II) and SEP for 12 months. The findings of CT scan were characterized according to the criteria suggested by Carrera and Hermanus and all results were analized thoroughly. The aim of this article is to underline the importance of the correlative studies between spinal CT and SEP in relation to lumbar disc syndrome.
Humans ; Tomography, X-Ray Computed*

OBJECTlVE To investigate the effect of α-glycan isolated from Isatis indigotica on humoral immunity and cellular immunity functions in mice immunized with H1N1 influenza vaccine. METHODS BALB/c mice were immunized intramuscularly once with H1N1 influenza vaccine ( 3 μg) plusα-glycan ( 100μg) each mouse. The serum total antibody titer and its isotype antibody titer of immu-nized mice were analyzed by ELlSA at 5, 8, 10, 12 and 14 d after injection at vaccine. The proliferation activities of spleen T and B lymphocytes were determined with MTT method. The levels of cytokines interferon-γ( lFN-γ) , tumor necrosis factorα( TNF-α) , interleukin-4( lL-4) and lL-12 were measured by ELlSA kits. The populations of CD4+, CD8+, CD3+ and CD19+ lymphocytes were determined by flow cytometry. Furthermore, the proliferation rate of macrophages was studied with MTT method in vitro. RESULTS The α-glycan from I.indigotica could gradually induce high specific-antibody production 5-14 d after immunization with H1N1 influenza antigen plus theα-glycan in mice compared to immunization with antigen alone ( P<0.01) . After injection of antigen withα-glycan for 5 d, the main lgG isotype was lgM, and the titer levels of total lgG, lgG1 , lgG2a and lgG2b were also significantly raised following 5-14 d after immunization. The α-glycan significantly promoted the spleen T and B lymphocytes proliferation ( growth rate 44.2%and 37.8%) , stimulated the secretion of lFN-γand lL-12 of splenocytes ( P<0.01, P<0.05) , and also promoted lL-4 secretion of thymocytes (P<0.01). The polysaccharide significantly raised the percent age of CD3+T cells ( P<0.01) , CD3+/CD19+ T lymphocytes ( P<0.01) , and CD8+ T cells ( P<0.01) but decreased the percentage of CD4+/CD8+ T lymphocytes compared with antigen alone group ( P<0.01) . Furthermore, the α-glycan exhibited significant effects on the proliferation and TNF-α secre-tion of MH-S macrophages. CONCLUSlON Theα-glycan isolated from I.indigotica can improve humoral and cellular immunity response in mice immunized with H1N1 influenza vaccine.

Sister chromatid exchanges(SCEs) and cell cycle kinetics were proposed as a sensitive and quantitative assay for mutagenicity and cytotoxicity in short-term cultures of phytohemagglutinin(PHA)-stimulated human lymphocytes. Therefore, this study was performed to investigate the relation between the cytotoxic effects and sister chromatid exchanges. The results are summarized as follows: 1) The frequency of SCEs per cell are 13.1+/-2.8 in the lower concentration of 6.25x10(-9) M and 75.8+/-8.2 in the highest concentration of 1.00+/-10(-7) M. Mitotic index is decreased in the higher concentration of mitomycin C. The result indicates that mitomycin C led to a dose dependent increase in SCE frequency, but decrease in mitotic index. 2) Chromosomal analysis was performed on metaphase cells that have divided one, two, and three or more times for cell cycle kinetics by fluorescence-plus-Giemsa(FPG) technique. According to the increased but the cells of third division are greatly decreased. 3) The frequency of SCEs per chromosome by chromocomal group are decreased gradually from A group to G group. But relationships between specific chromosomal group and SCEs frequency are not found.
Cell Cycle ; Chromatids ; Humans ; Humans* ; Kinetics ; Lymphocytes ; Metaphase ; Mitomycin* ; Mitotic Index ; Siblings* ; Sister Chromatid Exchange*

PURPOSE: The purposes of this study are to evaluate normal MR spectroscopy (MRS) data of the cerebellum and pons, and to evaluate intra-unit and inter-unit differences of the results. MATERIALS AND METHODS: Nine normal volunteers (mean age 23 years) were studied with two 1.5 Tesla MR units (A and B units). A total of four sessions of MRS study were performed with two sessions in each MR unit in each volunteer. In each session, MRS data were obtained from bilateral cerebellar hemisphere and pons. MRS was performed using spin-echo single voxel technique with repetition time of 2000 ms, echo time of 288ms and 128 averagings. Voxel size was 2x2x1.5 cm in the cerebellum and 1.5x1.5x1.5 cm in the pons. Metabolite ratios of NAA/Cho, NAA/Cr, NAA/(Cho+Cr) and Cr/Cho (both peak heights and the peak areas) were compared among the results of four sessions of MRS for evaluation of intra-unit and inter-unit differences. RESULTS: In the cerebellum, mean ISD values of peak height NAA/Cho, NAA/Cr, NAA/(Cho+Crl) and Cr/Cho ratios obtained in the first session of A unit were 1.08+/-0.16, 1.44+/-.286, 0.61+/-.09 and 0.76+/-,13, respectively. Comparing with the results of the second session, intra-unit differences were 3-7%. In B unit intra-unit differences were 1-9% , except for 22% of Cr/Cho ratio. Inter-unit differences between A and B units were 1-26%. In the pons, mean (SD values of peak height NAA/Cho, NAA/Cr, NAA/(Cho+Crl and Cr/Cho ratios obtained in the first session of A unit were 1.51+/-.35, 3.35+/-.78, 1.02+/-.16 and 0.47+/-,14, respectively. Mean NAA/Cho, NAA/Cr and NAA/(Cho+Cr) ratios of the pons were significantly higher than those of the cerebellum. Intra-unit differences were 2-21% in A unit and 4-l8% in B unit. Inter-unit differences between A and B units were 1-l8%. The mean values obtained by using peak area were generally higher and wider in range than those of peak height in both units. CONCLUSION: Mean NAA/Cho, NAA/Cr and NAA/(Cho+Cr) ratios of the cerebellum were significantly lower than those of the pons. Intra-unit differences of most metabolites ratios were generally not significant, whereas inter-unit differences were greater than intra-unit differences in more metabolite ratios. Therefore, normal MRS data of the cerebellum and the pons should be obtained in every MR unit, before MRS applications in the diseases of the cerebellum and the pons.
Cerebellum* ; Healthy Volunteers ; Magnetic Resonance Spectroscopy ; Pons* ; Spectrum Analysis ; Volunteers

Objective To understand the situation and genotype distribution of spotted fever group rickettsia (SFGR) in the border area of Tumen River Basin in free ticks in Yanbian Korean Autonomous Prefecture (Yanbian Prefecture), Jilin Province. Methods From April to September, 2017, ticks were collected using flagging method from Hunchun, Tumen, Helong and Longjing cities in the Tumen River basin of Yanbian Prefecture. Outer membrane protein A (ompA) was detected by Polymerase Chain Reaction (PCR), then, the species were identified by gene sequencing and analyzed systematically. The positive rate of pools and MIR(minimum infection rate per 100 ticks,MIR) of SFGR were calculated, and the difference of positive rate of pools among ticks with different characteristics was compared by Chi?square test. Results A total of 3 079 ticks were collected and divided into 536 pools. The positive rate of pools of SFGR nucleic acid was 39.7% (213 pools). The MIR of SFGR was 6.9%.The positive rate of pools of SFGR in Dermacentor silvarum, Haemaphysalis concinna, Haemaphysalis japonica, Haemaphysalis longicornis and Ixodes persulcatus were 80.4% (41/51), 14.0% (25/179), 20.2% (18/89), 78.9% (101/128) and 25.9% (21/81), and the difference was statistically significant (P<0.001). There was statistical difference in the positive rate of pools of SFGR in developmental stages of ticks (P<0.001); the positive rate of pools of female adults, male adults, nymph and larvae were 36.4% (95/261), 34.2% (67/196), 56.3% (40/71) and 7/8, and the MIR was 7.9%, 7.7%, 4.9% and 3.5%. The five genotype was detected which was Candidatus Rickettsia longicornii, Rickettsia raoultii, Rickettsia heilongjiangensis, Candidatus Rickettsia tarasevichiae,Rickettsia monacensis and have 98%-100% homology with known gene sequences. Candidatus Rickettsia longicornii, Rickettsia raoultii, Rickettsia heilongjiangensis and Candidatus Rickettsia tarasevichiae showed close evolutionary relationship with known specie (have 98%-100% homology with known gene sequences); Rickettsia monacensis showed Far from evolutionary relationship with known species (have 98% homology with known gene sequences). Conclusion SFGR infection of ticks is common in the border areas of the Tumen River Basin. There was high diversity in SFGR species and tick species in the areas surveyed.

Objective To understand the situation and genotype distribution of spotted fever group rickettsia (SFGR) in the border area of Tumen River Basin in free ticks in Yanbian Korean Autonomous Prefecture (Yanbian Prefecture), Jilin Province. Methods From April to September, 2017, ticks were collected using flagging method from Hunchun, Tumen, Helong and Longjing cities in the Tumen River basin of Yanbian Prefecture. Outer membrane protein A (ompA) was detected by Polymerase Chain Reaction (PCR), then, the species were identified by gene sequencing and analyzed systematically. The positive rate of pools and MIR(minimum infection rate per 100 ticks,MIR) of SFGR were calculated, and the difference of positive rate of pools among ticks with different characteristics was compared by Chi?square test. Results A total of 3 079 ticks were collected and divided into 536 pools. The positive rate of pools of SFGR nucleic acid was 39.7% (213 pools). The MIR of SFGR was 6.9%.The positive rate of pools of SFGR in Dermacentor silvarum, Haemaphysalis concinna, Haemaphysalis japonica, Haemaphysalis longicornis and Ixodes persulcatus were 80.4% (41/51), 14.0% (25/179), 20.2% (18/89), 78.9% (101/128) and 25.9% (21/81), and the difference was statistically significant (P<0.001). There was statistical difference in the positive rate of pools of SFGR in developmental stages of ticks (P<0.001); the positive rate of pools of female adults, male adults, nymph and larvae were 36.4% (95/261), 34.2% (67/196), 56.3% (40/71) and 7/8, and the MIR was 7.9%, 7.7%, 4.9% and 3.5%. The five genotype was detected which was Candidatus Rickettsia longicornii, Rickettsia raoultii, Rickettsia heilongjiangensis, Candidatus Rickettsia tarasevichiae,Rickettsia monacensis and have 98%-100% homology with known gene sequences. Candidatus Rickettsia longicornii, Rickettsia raoultii, Rickettsia heilongjiangensis and Candidatus Rickettsia tarasevichiae showed close evolutionary relationship with known specie (have 98%-100% homology with known gene sequences); Rickettsia monacensis showed Far from evolutionary relationship with known species (have 98% homology with known gene sequences). Conclusion SFGR infection of ticks is common in the border areas of the Tumen River Basin. There was high diversity in SFGR species and tick species in the areas surveyed.

Objective: To understand the situation and genotype distribution of spotted fever group rickettsia (SFGR) in the border area of Tumen River Basin in free ticks in Yanbian Korean Autonomous Prefecture (Yanbian Prefecture), Jilin Province. Methods: From April to September, 2017, ticks were collected using flagging method from Hunchun, Tumen, Helong and Longjing cities in the Tumen River basin of Yanbian Prefecture. Outer membrane protein A (ompA) was detected by Polymerase Chain Reaction (PCR), then, the species were identified by gene sequencing and analyzed systematically. The positive rate of pools and MIR(minimum infection rate per 100 ticks,MIR) of SFGR were calculated, and the difference of positive rate of pools among ticks with different characteristics was compared by Chi-square test. Results: A total of 3 079 ticks were collected and divided into 536 pools. The positive rate of pools of SFGR nucleic acid was 39.7% (213 pools). The MIR of SFGR was 6.9%.The positive rate of pools of SFGR in Dermacentor silvarum, Haemaphysalis concinna, Haemaphysalis japonica, Haemaphysalis longicornis and Ixodes persulcatus were 80.4% (41/51), 14.0% (25/179), 20.2% (18/89), 78.9% (101/128) and 25.9% (21/81), and the difference was statistically significant (P<0.001). There was statistical difference in the positive rate of pools of SFGR in developmental stages of ticks (P<0.001); the positive rate of pools of female adults, male adults, nymph and larvae were 36.4% (95/261), 34.2% (67/196), 56.3% (40/71) and 7/8, and the MIR was 7.9%, 7.7%, 4.9% and 3.5%. The five genotype was detected which was Candidatus Rickettsia longicornii, Rickettsia raoultii, Rickettsia heilongjiangensis, Candidatus Rickettsia tarasevichiae,Rickettsia monacensis and have 98%-100% homology with known gene sequences. Candidatus Rickettsia longicornii, Rickettsia raoultii, Rickettsia heilongjiangensis and Candidatus Rickettsia tarasevichiae showed close evolutionary relationship with known specie (have 98%-100% homology with known gene sequences); Rickettsia monacensis showed Far from evolutionary relationship with known species (have 98% homology with known gene sequences). Conclusion SFGR infection of ticks is common in the border areas of the Tumen River Basin. There was high diversity in SFGR species and tick species in the areas surveyed.