Objective To investigate influence of laser positioning system to position repeatability of patients treated with radiotherapy for pelvic tumors.Methods Forty patients with pelvic tumors were divided into two groups,using laser positioning system positioning (20 cases) and conventional positioning (20 cases),respectively,CBCT was used to verify and analyze the setup errors of two groups.Results The setup errors on X,Y and Z axes in laser positioning system positioning group were (2.63±1.07) mm,(2.38±1.28) mm and (2.46±1.21) mm,they were (3.04±1.22) mm,(2.55±1.35) mm and (3.09±1.37) mm in conventional positioning group.It has significance reduce on X and Z axes (P =0.040,0.003,respectively) by using laser positioning system,and has no significance on Y axis (P =0.432).Conclusion It can improve patient positioning repeatability effectively by using laser positioning system for patient positioning.

Objective To compare the errors of double-center and single-center setup, and to study the role of both on reducing the rotational setup errors for the patients with esophageal carcinoma depend on rigid registration errors between online kV-cone-beam computed tomography (kV-CBCT) images and plans for CT images. Methods 20 patients with middle esophageal carcinoma received image scanning before treatment every week by using double-center setup and CBCT, and single-center setup images of 20 patients were taken from the X volume image (XVI) system. Then the images of both setup types, registration errors of CT image and rotational setup errors were compared respectively. Every patient received kV-CBCT scanning analysis before treatment every week, and 6 times in total. 240 group of kV-CBCT images from all of the patients were off-line matched with plans for CT images to calculate the errors of X-axis, Y-axis, Z-axis. Then the data of linear errors and rotational setup errors from patients were collected, aiming at putting the error data into the patients treatment program and analyzing the significances. Results The standard registration of double-center setup was as follows: T (X) (0.28 ±0.19) cm, T (Y) (0.27 ±0.19) cm, T (Z) (0.33 ±0.12) cm, R (X) (0.40 ±0.19)° , R (Y) (0.30 ±0.18)° , R (Z) (0.30 ±0.19)° . The standard registration of single-center setup was as follows:T(X) (0.32±0.20) cm, T(Y) (0.29±0.25)cm, T(Z) (0.31±0.16) cm, R(X) (2.2±0.68)°, R(Y) (0.5±0.32)°, R(Z) (2.10±0.60)°. There were statistical differences between linear errors in T(X) and rotational setup errors in R(X), R(Y) or R(Z) (P< 0.05). Conclusion Double-center position can reduce the rotational setup errors, especially in X-axis, Y-axis errors, and may provide more help for the radiation oncology departments without on-board CBCT.

Objective:To screen the differentially expressed exosomal miRNAs derived from liver cancer stem cells (LCSCs) and its effect on the malignant biological characteristics of liver cancer cells.Methods:miRNA expression profile chip was used to analyze the differentially expressed exosomal miRNA derived from LCSCs. The effects of miRNA on malignant phenotypes of LCSCs were identified. The cells were further treated with doxorubicin at different concentrations (0, 150, 300 μmol/L), and the expression level of miR-196a was detected by quantitative real-time PCR (qRT-PCR). The apoptosis of liver cancer cells cultured by exosomes derived from LCSCs (Exo-NC group) and exosomes derived from miR-196a inhibited LCSCs (Exo-Inhibitor group) and the activity of caspase3/7 under the action of exosomes from LCSCs were detected. Nude mice were randomly divided into Do-PBS group, Do-Exo-Inhibitor group and Do-Exo-NC group using random number table method, with 5 mice in each group, and the effect of miR-196a on nude mice xenograft tumor model with liver cancer cells was analyzed.Results:In this study, exosomes were isolated and purified from CD133 + Huh7 stem cell culture supernatant. miR-7162-3p, miR-1910-5, miR-3613-3p, miR-196a and miR-155-5p were up-regulated, while miR-1246 and miR-3613-5p were down-regulated. miR-7162-3p, miR-196a and miR-155-5p in exosomes had important effects on the self-renewal ability of LCSCs. miR-1910-5p, miR-196a and miR-155-5p had important effects on the invasion ability of liver cancer stem cells, among which miR-196a had the most significant inhibitory effect. Treatment for 24 h, the miR-196a expression level of the 0, 150 and 300 μmol/L doxorubicin was 0.96±0.05, 1.23±0.05 and 2.33±0.03 respectively, with a statistically significant difference ( F=996.90, P<0.001). Treatment for 48 h, the miR-196a expression level of the 0, 150 and 300 μmol/L doxorubicin were 1.02±0.07, 2.35±0.05 and 2.89±0.55 respectively, with a statistically significant difference ( F=303.00, P<0.001). When the concentration of doxorubicin was 0 and 300 μmol/L, the apoptosis rates of the Exo-NC group were 9.37%±0.19% and 11.64%±0.27%, and those of the Exo-Inhibitor group were were 18.80%±1.91% and 22.79%±1.57%, with statistically significant differences ( t=4.41, P=0.048; t=4.96, P=0.038). When doxorubicin was not used, the ratios of caspase3/7 in the Exo-NC group at 24 h and 48 h were 0.94±0.08 and 0.97±0.09, and those in the Exo-Inhibitor group were 1.56±0.01 and 1.58±0.01, with statistically significant differences ( t=11.41, P=0.008; t=6.07, P=0.026). Under 300 μmol/L doxorubicin, the ratios of caspase3/7 in the Exo-NC group at 24 h and 48 h were 0.95±0.07 and 1.36±0.08, and those in the Exo-Inhibitor group were 2.84±0.08 and 3.20±0.14, with statistically significant differences ( t=24.20, P=0.002; t=15.78, P=0.004). The results of xenograft tumor in nude mice showed that the tumor volumes of Do-PBS, Do-Exo-Inhibitor and Do-Exo-NC groups increased successively, which were (1 051.86±89.90) mm 3, (1 310.91±86.66) mm 3 and (2 185.14± 352.34) mm 3 respectively, with a statistically significant difference ( F=30.28, P<0.001). The weights of the transplanted tumors in the 3 groups increased successively, which were (0.36±0.10) g, (0.39±0.12) g and (0.76±0.16) g respectively, with a statistically significant difference ( F=11.81, P=0.002). The expression of miR-196a in tumors was significantly decreased after miR-196a inhibitor transfection. The expression levels of the 3 groups were 1.05±0.16, 0.38±0.08 and 2.17±0.26, with a statistically significant difference ( F=48.93, P<0.001). Conclusion:The exosomal secreted by LCSCs can enhance the resistance of liver cancer cells to doxorubicin by miR-196a.

Psoriatic arthritis (PsA) is a complicated psoriasis comorbidity with manifestations of psoriatic skin and arthritic joints, and tailoring specific treatment strategies for simultaneously delivering different drugs to different action sites in PsA remains challenging. We developed a need-based layered dissolving microneedle (MN) system loading immunosuppressant tacrolimus (TAC) and anti-inflammatory diclofenac (DIC) in different layers of MNs,