Objective struclured clinical examination (OSCE) is a kind of examination which could objectively evaluate the students′clinical skills.Nowadays,OSCE are wildly applied in medical educational field throughout the world.Timely discussion and analysis on the problems existed in the implementation process of OSCE is necessary.Measures should be taken to improve the OSCE examination and to meet the requirements of higher clinical practice training level such as increasing clinical skill simulation training hardware investment,optimizing settings and conlents of the examination and the test stations as well as introducing standardized patients (SP) and other measures.

Objective To analyze the distribution of B-cell subtypes and IgG subclasses in pa-tients with non-small cell lung cancer ( NSCLC) and to investigate their potential functions in the progress of NSCLC.Methods Flow cytometry analysis was used to detect the distribution of immature B cells, memory B cells and mature B cells in 25 healthy subjects and 55 patients who were at different clinical stages of NSCLC.Enzyme-linked immune-sorbent assay ( ELASA) was performed to measure the concentrations of IgG1, IgG2, IgG3, IgG4 and total IgG, as well as the ratio of each IgG subclass in total IgG.Results The percentages of immature and memory B cells in CD19+B cells were positively correlated with the progress of NSCLC.The ratio of IgG4/IgG gradually increased along with the development of NSCLC, while that of the other three IgG subclasses showed no significant changes as compared with that of the control group.Conclu-sion The imbalanced distribution of B-cell subtypes and the up-regulated ratio of IgG4/IgG were closely as-sociated with the development of NSCLC.This study paved the way for further investigation on more effective immune therapy strategies targeting NSCLC.

Objective To establish a mouse model of lymph node metastasis of breast cancer cells by luciferase imaging assay,to monitor early process of lymph node metastasis,and to evaluate the effect of X-ray radiation therapy on tumor.Methods The mouse mammary cancer cell line 4T1-Luc expressing luciferase was inoculated subcutaneously into the paw pad of nude mice to establish a model of subcutaneous lymph node metastasis.The lymph node metastasis in nude mice was continuously observed by in vivo fluorescence imaging system,and the nude mice with early lymph node metastasis of breast cancer cells were divided into control group and treatment group randomly.The radiotherapy effect was observed by in vivo fluorescence imaging system and evaluated by the pathological changes of HE staining of tumor tissue.Results A mouse lymph node metastasis model of breast cancer cells was successfully established,and the volume of primary tumor in paw correlated with the fluorescence photon number positively (r =0.958,P ＜ 0.001).On the twenty-fourth day after inoculation,the fluorescence photon number in pad tumor and popliteal fossa tumor of treatment group were significantly decreased in comparison with the control group (t =32.58,P ＜ 0.05),and the inhibition ratio of radiotherapy on tumor growth approached to 85 ％.HE staining showed that the apoptosis and necrosis in irradiated tumor was obviously higher than that in control group.Conclusions Bioluminescence imaging technique can be used to evaluate the effect of X-ray on breast cancer suppression and lymph node metastasis in mice.

Objective Through the detections of the heterozygote frequencies tests of fetal specific genes PLAC4 and COL6A2 mRNA alleles in plasma of pregnant women, to explore its possibility of application in the noninvasive prenatal screenings of trisomy-21. Methods A toltal of 500 cases (males and females 250 cases respectively)of Han ethnic groups with Henan Provice of China who were subject to the physical checkup clinic of the Third Affiliated Hospital,Zhengzhou University from June to December, 2013 were selected as the healthy physical checkup group, and such techniques as DNA sequencing and PCR-restriction fragment length polymorphism (RFLP) were adopted to the determinations of the heterozygote frequencies of the single nucleotide polymorphism(SNP)of the PLAC4 and COL6A2 genes in the maternal peripheral blood in the healthy physical checkup group, and the differential comparisons of the determination results of the SNP heterozygote frequencies and the corresponding heterozygote frequencies in the National Center for Biotechnology Information (NCBI) database;30 cases of healthy pregnant women who spontaneously underwent pregnancy checkups at the maternity clinic were randomly selected as the healthy pregnancy group, and real-time fluorescence quantitative reverse transcription-PCR technique was adopted for determining the expression levels of PLAC4 and COL6A2 mRNA in the peripheral blood of pregnant women of 8 weeks, 10 weeks, 12 weeks, 14 weeks and 16 weeks;40 cases of the same phase were selected for acting as the specimens for the karyotype analyses of the amniotic fluid cells, among which 20 cases were trisomy-21, and the 20 cases of the negative control group, and reverse transcription-multiplex ligation dependent probe amplification (RT-MLPA) technique was adopted for screening the fetal trisomy-21. Results (1) The allele heterozygote frequencies of the SNP of the healthy physical checkup group:determinations of the genotypes and hybrid rates of the 10 SNP sites of the PLAC4 and COL6A2 genes indicated that those with higher heterozygote frequencies were respectively rs7717, rs559, rs1044598, rs59066201 and rs1042917, with population coverage of 98%. Among them, the allele hybrid rates of rs59066201 were never seen in the NCBI database;in the respective comparisons of the allele hybrid rates of rs8130833, rs9977003 and rs7844 with the hybrid rates of the NCBI database, the variations had statistical significance (P<0.05). (2) The expression levels of PLAC4 and COL6A2 mRNA of the different pregnancy weeks of the healthy pregnancy group: the levels of PLAC4 mRNA in the peripheral blood of women of 8 weeks, 10 weeks, 12 weeks, 14 weeks and 16 weeks of pregnancy were respectively 7.22 ± 1.05, 8.02±1.41,9.51±1.69,11.33±2.11 and 13.31±2.58, with their expression levels rising along with the increase of the pregnancy weeks; among them, the comparison of pregnancy 8 weeks and pregnancy 10 weeks, the variations had no statistical significance (P>0.05);in the mutual comparisons among the expression levels of the various pregnancy weeks, the variations had statistical significance (P<0.05). The expression levels of COL6A2 mRNA in 8 weeks, 10 weeks, 12 weeks, 14 weeks and 16 weeks were respectively 8.95 ± 1.28, 11.19 ± 1.36,15.00 ± 1.58,16.87 ± 1.72 and 18.96 ± 2.79, with their expression levels rising along with the increase of the pregnancy weeks, and in the mutual comparisons between the expression levels of the various pregnancy weeks, the variations all had statistical significance (P<0.05). (3) Prenatal screenings of trisomy-21 in the validation group of the trisome:a total of 5 sites of rs7717, rs559, rs1044598, rs59066201 and rs1042917 were selected from the allele heterozygote frequencies of SNP sites were selected from the subjects of the healthy physical checkup group, and 10 cases of trisomy-21 specimens and 10 cases of negative CTR specimens were accurately determined, with the sensitivity reached 80%(17/20), and the specificity reached 90%(18/20). One case of the trisomy-21 and two negative cases were both homozygotes, and among the trisomy-21 specimens of two cases, only one SNP was a heterozygote, and it was impossible to conduct screenings on these 5 cases, with the screening accuracy reaching 100%(35/35). Conclusions Fetal specific genes PLAC4 and COL6A2 mRNA are expressed in the peripheral blood of pregnant women in different gestational age;its expression level increases with the increase of gestational age. Among them, five SNP including rs7717, rs559, rs1044598, rs59066201 and rs1042917 show highest heterogeneity rate, which is different from the corresponding heterogeneity rate in NCBI database. RT-MLPA technology is a rapid, effective, noninvasive and low cost method of prenatal screening 21 trisomy.

Objective: To observe the conditions of the activating areas in the brain evoked by needling Shenmen (HT 7) acupoint. Methods: Twelve healthy young volunteers were needled at Shenmen (HT 7) acupoint with rotating and twisting techniques. Functional magnetic resonance imaging (fMRI) was adopted to detect the brain activating areas, TR/TE/FA=3560 ms/50 ms/90°. After scanning, the images were dealt with SPM2. Results: Needling Shenmen (HT 7) primarily activated BA2 and BA1 of the gyms postcentralis in right-sided frontal lobe, BA47 of left-sided inferior frontal gyms and BA43 of left-sided gyms postcentralis, and also activated BA40 of inferior parietal lobule in right-sided parietal lobe, BA22 of gyrus temporalis superior in left-sided lobus temporalis, and BA40 of right-sided insula; however, the sham acupoints could not activate these nucleus. Conclusion: Needling Shenmen (HT 7) can activate the relevant functional areas in the brain.

Objective To investigate the impact of parameters setting on image quality and radiation dose of low-dose chest CT scanning when iCT tube current was set as 17 mAs.Methods Two hundred volunteers who accepted low-dose chest CT screening with tube current was set as 17 mAs were randomly divided into four groups according to the tube voltage and automatic exposure control (DoseRight) settings (group A:120 kV,DoseRight;group B:100 kV,DoseRight;group C:120 kV,fixed tube current;group D:100 kV,fixed tube current).Then hybrid iterative reconstruction (HIR:iDose4) and iterative model reconstruction (IMR) were performed on all scanned images of lung and mediastinal window algorithm,respectively.The effective dose and image quality of 4 groups were compared.Results There were significant differences of image quality score and effective dose among 4 groups.The image quality of group A and B were better than that of group C (P＜0.05),and of group D was the worst compared with the other three groups (P＜0.05).Image quality scores of the mediastinal window of group C and D and the lung window of group D at iDose4 reconstruction were lower.SNR value of group A,B,C,D decreased in order (P＜0.01).Group A had the highest effective dose (P＜0.01),while the effective dose of group B and group C had no significant difference (P=0.055),and group D had the lowest effective dose (P＜ 0.01).Conclusion When tube current was set as 17mAs at iCT,selecting 100 kV tube voltage,DoseRight and IMR reconstruction arithmetic can obtain satisfactory image quality and low radiation dose.

Objective:To observe the changes of optic disc structure in patients with high myopia and the correlation with the morphological markers of the fundus.Methods:A retrospective study. From July 2018 to January 2020, 90 patients (155 eyes) diagnosed as high myopia in Department of Ophthalmology of Beijing Friendship Hospital affiliated to Capital Medical University were included in the study. Among them, there were 31 males (52 eyes) and 59 females (103 eyes), with age of 57.1±14.2 years old and axial length (AL) of 28.5±2.6 mm. According to the classification of myopic macular degeneration, patients were divided into 4 groups based on forms and degree of lesions, including non-pathological myopia group, mild traction lesions group, severe traction lesions group and neovascular lesions group, 35, 58, 41, 21 eyes, respectively. The digitized fundus photographs and an Image J system were used to measure the horizontal, vertical, maximal, and minimal diameter of the optic disc, the horizontal and vertical diameter of the parapapillary δ zone and γ zone, ovality index, distance between the most superior point of the temporal superior arterial arcade and most inferior point of the temporal inferior arterial arcade (VDA), angle between the temporal arterial arcade and optic disc (angle kappa), distance between the optic disc center and the fovea (DFD), angle between the horizontal disc axis and the disc-fovea line (DFA). The correlation between the diameter of the optic disc and other parameters was analyzed. Univariate and multivariate analysis were used to compare differences between groups.Results:The horizontal diameter of the optic disc was positively correlated with the horizontal diameter of the δ zone ( r=0.300, P<0.001), Kappa angle ( r=0.260, P=0.003), and elliptic index ( r=0.650, P<0.001); it was negatively correlated with DFD ( r=-0.190, P=0.030). Optic disc vertical diameter and optic disc horizontal diameter ( r=0.280), δ-zone horizontal diameter ( r=0.330) and vertical diameter ( r=0.460), γ-zone horizontal diameter ( r=0.430) and vertical diameter ( r=0.390), DFD ( r=0.390) was positively correlated ( P<0.001); it was negatively correlated with DFA ( r=-0.210, P=0.001) and Kappa angle ( r=-0.210, P=0.004). Compared with the non-pathological myopia group, there were statistically significant differences in the horizontal and vertical diameters of the optic disc in the severe traction disease group ( P<0.05). Among them, the horizontal diameter difference did not depend on the eye axis and age difference; the vertical diameter difference was caused by the eye axis difference. Compared with the non-pathological myopia group, the difference in the horizontal diameter of the optic disc in the neovascular disease group was statistically significant ( P<0.05), and did not depend on the difference in the axis and age; the difference in the vertical diameter of the optic disc was not statistically significant ( P>0.05). Conclusion:The morphology of optic disc was related to several fundus morphological markers, which was differentiated according to the age, AL and the degree of disease in patients with high myopia.

Objective:To investigate the application value of optical coherence tomography (OCT) and intravascular ultrasound (IVUS) in evaluating flow diverter (FD) apposition and endothelialization in aneurysm animal models, and analyze the effect of incomplete stent apposition (ISA) on aneurysm lumen healing and stent endothelialization.Methods:Lateral common carotid artery aneurysm models in swines were established by surgical method and then FD was implanted. Immediately after surgery, OCT and IVUS were used to evaluate the locations and degrees of ISA, and difference between these 2 methods in evaluating FD apposition was compared. DSA was performed at 12 weeks after surgery to evaluate the aneurysm occlusion (Kamran grading) and stent patency. OCT and IVUS were used again to observe the stent endothelial situation; by comparing with histopathologic results, effect of ISA on aneurysm healing and stent endothelialization was analyzed.Results:Lateral common carotid artery aneurysm models in 6 swines were established, and 6 Tubridge FDs were successfully implanted. Compared with IVUS (3 stents, 4 locus), OCT could detect more ISA (6 stents, 14 locus); and the vascular diameter change area (7 locus), aneurysm neck area (4 locus) and the head and tail of FD (3 locus) were the main sites of FD malapposition; average distance between stent wire and vessel wall was (560.14±101.48) μm. At 12 weeks after surgery, DSA showed that 1 patient had a little residual contrast agent at the aneurysm neck (Kamran grading 3), and the remaining 5 had complete aneurysm occlusion (Kamran grading 4). One FD had moderate lumen stenosis, and the other 5 FDs had lumen patency. OCT indicated mostly disappeared acute ISA; ISA proportion decreased to 21.4 % (3/14), including 2 in the aneurysm neck and 1 in the partial stent. Histopathological results showed bare stent woven silk, without obvious endothelial coverage; in one FD with luminal stenosis, intimal hyperplasia was mainly composed of vascular smooth muscle cells.Conclusion:In carotid artery aneurysm model with FD implantation, OCT can detect more ISA than IVUS; most acute ISA have good outcome at 12 th week of follow-up, while severe ISA can cause delayed FD endothelialization and delayed aneurysm occlusion.

【Objective】 To establish reference intervals for serum soluble transferrin receptor (sTfR) and sTfR/log serum ferritin index (sTfR/lgSF) in apparently healthy adults in the Wuhan area, so as to provide reference for clinical diagnosis and treatment of iron deficiency and iron-deficiency anemia. 【Methods】 A total of 273 individuals from the Wuhan Aisa General Hospital, including health examination participants and blood donors, were selected to measure sTfR, other iron metabolism indicators and high sensitivity C-reactive protein(hsCRP). The sTfR/lgSF values were calculated and reference intervals for sTfR and sTfR /lgSF were established using the percentile method (P2.5 to P97.5). Spearman correlation analysis was used to evaluate the relationships between sTfR, sTfR/lgSF, and other iron metabolism indicators, as well as hsCRP. 【Results】 The sTfR levels (M, mg/L) between males and females (1.01 vs 1.07) were not statistically significant (P>0.05), but the sTfR/lgSF levels if males were significantly lower than those in females (0.45 vs 0.62)(P<0.05). There was no significant difference in sTfR (M, mg/L) and sTfR/lgSF (M) among different age groups, with values of 1.07 vs 1.02 vs 1.00 and 0.52 vs 0.53 vs 0.51, respectively(P>0.05). The reference interval for STfR was (0.72-1.68) mg/L, the sTfR/lgSF reference interval was (0.31-0.88) for males, and (0.37-1.19) for females. Correlation analysis showed no correlation between sTfR, sTfR/lgSF and hsCRP (r=0.043, P>0.05; r=-0.064, P>0.05), while serum ferritin(SF), serum iron(SI), transferrin saturation(TSAT)were correlated with hsCRP (r=0.128, P<0.05; r=-0.195, P<0.01; r=-0.173, P<0.01).There was no correlation between sTfR and SF (r=-0.115, P>0.05), while sTfR/lgSF was significantly correlated with and SF (r=-0.685, P<0.01). 【Conclusion】 Preliminary reference intervals for serum sTfR and sTfR/lgSF in apparently healthy adults in the Wuhan has been established. sTfR and sTfR/lgSF are not affected by inflammatory factors and are significant for identifying iron deficiency in anemia patients with elevated serum ferritin caused by inflammation.

Objective: To explore the gene transduction method of chimeric antigen receptor (CAR) mediated by novel cationic polymer nanocarrier mPEG-P (Asp-AED-g-HFB) (PAEF) and PigyBac transposon system to modify natural killer (NK) cells, providing a new strategy for immunotherapy of cancer cells. Methods: PAEF/DNA (transposase+transposon) complex were prepared. The particle size distribution and surface potential of PAEF/DNA complexes were measured with Nano-ZSE Dynamic Light Scattering System (Malvern Instruments). The DNA encapsulation rate, release and stability of PAEF were evaluated by DNA gel electrophoresis, and then by combiningwithparticlesizeandsurfacepotentialtodeterminethepreferentialN/PratiotoenterNKcells.Thecell cytotoxicity of PAEF/DNA complexes under different N/P ratios was analyzed by CCK-8 cytotoxicity test. Transduction efficiency of NK cells was evaluated by Fluorescence microscopy and Flow cytometry, and the feasibility of PAEF gene transfection vectors was assessed. Results: PAEF could encapsulate DNA to form nano-complexes with the diameter of 100-150 nm, which was suitable to mediate DNA entering into cells. PAEF could completely encapsulate DNA with N/P ratio of 20. In the presence of reducing agent dithiothreitol (DTT), PAEF had a good ability to release DNA. NK-92 cells transfected with PAEF/DNA complex, which was formed at the N/P ratio of 80, attained a significantly higher cell viability than cells of lipofectamine transfection group [(72.50±3.9)% vs (64.03±1.8)%, P<0.05]; Fluorescence microscopic observation showed more fluorescence and higher fluorescence intensity in cells of PAEF/DNA group; Flow cytometry showed the highest transfection efficiency of 83.4%. Conclusions: Nanocarrier PAEF can encapsulate DNA well by electrostatic adsorption, and has good biocompatibility and high efficiency for gene transduction. It provides a good experimental basis for adoptive immunotherapy.