【Abstract】Objective To investigate the irradiating effect of low intensive microwave (LIM) on pathological process of blood vessel restenosis(RS) and assess the probability of LIM irradiation to prevent was used RS.Methods Fortyfour male healthy New Zealand rabbits were randomly divided into 2 groups. Fogarty catheter traumatize to the tunica intima of iliac artery so as to establish RS models. Two thousand four hundred and fifty MHz microwave with different power of 2 ,5 and 10 mW/cm2 was used, locally to irradiate EIA in irradiating group (1 h/d). Specimens were obtained at different time of 3,7,14 and 28 d after operation. Morphological changes of tissues were observed with HE and EF staining and the area of tunica intima, tunica media and the rate of cavity stenosis were analyzed with image analysis system; apoptosis was detected with TUNEL; phenotype and microstructure of VSMC were observed with TEM. Results After microwave irradiating, inflammatory reaction in early period was suppressed, mural thrombus decreased, the proliferation and migration of VSMC depressed, the area of tunica intima and the rate of cavity stenosis obviously reduced comparing with the control group (P＜0.01). The rate of apoptosis cells showed that there were no obvious differences among each group on 3 d after operation (Pgt;0.05). At other different time, however, the rate of apoptosis cells in irradiating groups obviously increased than that of the control group (P＜0.01), particularly in the one with power of 5 mW/cm2 .The number of synthesis form VSMC in the control group occupied (93.50±3.45)% of the total number of VSMC on 14 d after operation. Most of VSMC appear contractile in irradiating group in which a lot of morphological changes of apoptosis in fibroblast and VSMC existed.Conclusion LIM irradiation could obviously prevented from pathologic procedure of RS. After LIM irradiating, inflammatory reaction in early period is suppressed, the proliferation and migration of VSMC depressed. LIM irradiation promotes cell apoptosis, effectively prohibites the occurring and development of RS. LIM irradiation has had relationship between quantity and effect, power span to effectively prohibit RS, particularly in the one with power of 5 mW/cm2.
ObjectiveTo discuss the value of dual-source CT Flash scanning in reducing the dose of radiation in 3D cardiac imaging. MethodWe collected 60 patients from March to August 2014 who should undergo cardiac 3D CT scanning before radiofrequency ablation. They were randomly divided into group A and B with 30 in each. Patients in group A underwent flash technology scanning, while those in group B accepted conventional retrospective electrocardiography-gated scanning. CARE Dose techniques were used to collect data. Scanning parameters were the same for both groups:collimation was 128×0.6 mm, reconstruction thickness was 0.75 mm, reconstruction interval was 0.7 mm, and field of view was 180-200 mm. After image acquisition, we measured the CT values and noise of left atrium and various branches of the pulmonary veins (upper left, lower left, upper right, and lower right). Statistical software was used for the two groups of images to analyze the carrier noise ratio (CNR), signal noise ratio (SNR), blinded scores, computed tomography dose index (CTDIvol), and dose-length product (DLP) of the left atrium and pulmonary vein. ResultsCNR and SNR of the left atrium and various pulmonary veins between the two groups had no significant differences (P>0.05) . Blinded scores between the two groups were not significantly different (P>0.05) . CTDIvol in group A and group B was respectively (2.92±0.38) and (20.15±12.09) mGy, with a significant difference (t=?7.803, P<0.001) . DLP of group A was (59.30±6.67) mGy·cm, significantly lower than that in group B [(334.43±216.71) mGy·cm] (t=?6.591, P<0.001) . Flash-efficient radiation dose was (0.83±0.94) mSv in group A, far below that in group B [(4.53±3.03) msv], and the difference was statistically significant (t=?6.684, P<0.001) . ConclusionsDual-source CT Flash technology applied in 3D cardiac scanning can reduce radiation dose as well as meet the needs of image diagnosis.
Objective To explore composition of volatile organic compounds (VOCs) in exhaled breath of low-dose radiation-damaged Sprague-Dawely (SD) rats by thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS), and search for the differential metabolites of VOCs in the series of rats after radiation damage, and establish a noninvasive radiation damage detection method. Methods SD rats were randomly divided into five groups (a blank group, a 0.5-Gy group, a 1-Gy group, a 2-Gy group, and a 3-Gy group), with 8 rats in each group. A low-dose radiation injury model was established in rats. After the cobalt source radiation damage was performed, the body weight of rats was recorded, peripheral blood hematology was analyzed, and the exhaled breath of rats was collected on the 1st, 5th, 9th and 13th day. The composition of VOCs in the exhaled breath was analyzed by using the TD30-GC-MS technique, and multivariate statistical analyses were carried out to explore and obtain the differentiated metabolites after the radiation damage. Results After radiation damage, the rats showed a short-term decrease in body weight, peripheral blood and lung tissue sections were different, and the content of VOCs components in the exhaled breath of the damaged rats was significantly different from that of the rats in the blank group. Among them, four VOCs, acetophenone, nonanal, decanal and tetradecane increased, while heptane, chlorobenzene, paraxylene and m-dichlorobenzene decreased. Conclusions Through the GC-MS analysis of the exhaled breath of rats, eight components of VOCs in the exhaled breath of rats can be used as differential metabolites of radiation damage. This study lays a foundation for the establishment of a GC-MS analysis method for the components of VOCs in the exhaled breath of rats, as well as for the development of a nondestructive analytical assay for biological radiation damage.
Objective To investigate the effects of ectomesenchymalstem cells on hematopoiesis after total body irradiation in rats. Methods The primary ectomesenchymal stem cells were isolated from E11.5 SD fetal mandibular processes by 25g/L trypsin and cultured with DMEM/F12. The morphology and growthrate were observed by inverted microscope. Eighty SD male rats randomly dividedinto ectomesenchymal stem cells group (n=20), fibroblast group(n=20), saline group(n=20) and control group(n=20), the first three groups were irradiated with 60Co γ rays at 6.0 Gy. The number of their bone marrow nucleated cells was counted after 4 weeks; the forming ability of colony-forming unit-granulocyte macrophage(CFU-GM) and histopathology of bone marrow were also observed. Results The cultured cells displayed monolayer growth and fibroblast-like with 2-4 processes. The ectomesenchymal stem cells could increase the number of bone marrow nucleated cells and peripheral blood white cell count, and improve the forming ability of CFU-GM. After 4 weeks of transplantation, the number of the peripheral blood white cells in group A was more than that in groups B and C(Plt;0.05), the contents of Hb in groups A and D was significantly higher than those in groups B and C(Plt;0.0). After 4 weeks, the bone morrow nucleated cells in group A were significant more than those in groups B and C(Plt;001); CFU-GM in groups A and D was higher than that in groups B and C(Plt;0.01). Conclusion Ectomesenchymal stem cells have characteristics of stem cells. It may improve hematopoiesis recovery of irradiated rats.
ObjectiveTo evaluate the value of 70 kV and sonogram-affirmed iterative reconstruction technique in CT examination for children with congenital heart disease. MethodsThirty children with congenital heart disease who underwent CT scan between January and September 2014 were included in this study. According to the different tube voltage, they were randomly divided into group A (80 kV) and group B (70 kV), with fifteen in each. All the children were scanned on a dual-source-CT (Siemens Definition Flash). Group A used filtered back projection reconstruction. Group B used sonogram-affirmed iterative reconstruction. We measured and calculated the pulmonary artery signal-to-noise ratio at the level of main pulmonary artery window, the signal-to-noise ratio of the ascending aorta, noise ratio contrast between the pulmonary artery and erector spinae and between the ascending aorta and erector spinae. The image quality for congenital heart disease was assessed by two senior radiologists. The measurement of radiation dose included effective dose (ED), volume CT dose index (CTDIvol) and dose length product (DLP). ResultsThere were no significant differences between group A and B in terms of pulmonary artery signal-to-noise ratio (14.54±3.77, 11.23±2.52), the signal-to-noise ratio of the ascending aorta (14.76±3.41, 12.31±3.47), the noise ratio contrast between pulmonary artery and erector spinae (12.04±3.96, 9.18±3.76) and between the ascending aorta and erector spinae (12.47±4.59, 9.77±4.41) (P > 0.05). There was significant difference between group A and group B in CTDIvol[(0.53±0.09), (0.38±0.03) mGy], DLP[(12.93±1.79), (6.67±0.72) mGy·cm], and ED[(0.34±0.05), (0.17±0.02) mSv] (P < 0.05). ConclusionThe application of 70 kV and sonogram-affirmed iterative reconstruction technique in CT examination for children with congenital heart disease can significantly reduce the radiation dose without any influence on image quality.
ObjectiveTo investigate the synergistic antitumor effects of ionizing radiation and the cytosine deaminase (CD)/5-flurocytosine (5-FC) system therapy in human pancreatic cancer cell.MethodsThe expression vector containing CD was transfected into the human pancreatic cancer cell line PC3. The clones were picked out after G418 selection. The CD gene integration and expression were confirmed by the RT-PCR. The cytotoxicity to the cells with or without CD and (or) ionizing radiation under the treatment with 5-FC was measured by the MTT assay. The clonogenic assay was used to investigate the radiosensitizing effect of 5-FC on the PC3 cells transfected or untransfected with CD gene.ResultsThe CD gene was stably expressed in the PC3 cells transfected with CD gene. The cytotoxic effect of 5-FC was superior on the PC3 cells transfected than that of untransfected with CD gene (P<0.05) and which were enhanced in combination with the ionizing radiation (P<0.05). The CD/5-FC enhanced the radiosensitivity of PC3 cells transfected with CD gene (P<0.05). The change in the radiosensitivity was quantified by calculating the sensitization enhancement ratio (SER) at the clinically relevant dose of 2 Gy. The SER was 1.5 in the PC3 cells transfected with CD gene by giving ionizing radiation of 2 Gy.ConclusionsCD/5-FC system is a potenial radiosensitizer in PC3 cells transfected with CD gene. Ionizing radiation and CD/5-FC system is more effective for killing effect of PC3 cells than ionizing radiation or CD/5-FC system alone.
The Monte Carlo N-Particle (MCNP) is often used to calculate the radiation dose during computed tomography (CT) scans. However, the physical calculation process of the model is complicated, the input file structure of the program is complex, and the three-dimensional (3D) display of the geometric model is not supported, so that the researchers cannot establish an accurate CT radiation system model, which affects the accuracy of the dose calculation results. Aiming at these two problems, this study designed a software that visualized CT modeling and automatically generated input files. In terms of model calculation, the theoretical basis was based on the integration of CT modeling improvement schemes of major researchers. For 3D model visualization, LabVIEW was used as the new development platform, constructive solid geometry (CSG) was used as the algorithm principle, and the introduction of editing of MCNP input files was used to visualize CT geometry modeling. Compared with a CT model established by a recent study, the root mean square error between the results simulated by this visual CT modeling software and the actual measurement was smaller. In conclusion, the proposed CT visualization modeling software can not only help researchers to obtain an accurate CT radiation system model, but also provide a new research idea for the geometric modeling visualization method of MCNP.
目的 研究薏苡仁水提液对受辐射小鼠外周血白细胞、骨髓有核细胞数量及微核率变化的影响，并检测白细胞介素（IL）-1、IL-2、超氧化物歧化酶（SOD）基因的变化以探讨其抗辐射损伤的作用机制。 方法 用薏苡仁水提液在受辐射前后对小鼠进行灌胃，对辐射后小鼠外周血白细胞、骨髓有核细胞计数，计算微核率，逆转录-聚合酶链反应（RT-PCR）检测IL-1、IL-2、SOD基因的变化，对实验结果进行统计学分析。 结果 随薏苡仁水提液剂量的加大，受照射小鼠骨髓有核细胞数不断增多，且微核数呈降低趋势；高剂量组与空白对照组相比，照射后第7天小鼠外周血白细胞数差异无统计学意义（P＞0.05），且3个剂量组外周血白细胞数均高于辐射对照组，差异有统计学意义（P＜0.01）；薏苡仁水提液高、中剂量组IL-1、IL-2、SOD基因的相对表达量均高于空白对照组和辐射对照组（P＜0.01）。 结论 薏苡仁水提液可能具有促使骨髓有核细胞快速释放、加快外周血白细胞数量恢复进度的作用，且具有降低受辐射小鼠骨髓有核细胞和外周血淋巴细胞微核率的作用；再者，薏苡仁水提液可上调受辐射小鼠机体SOD、IL-1、IL-2的表达水平，具有增强自由基清除、抗辐射和免疫保护调节的作用。