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Objective:To evaluate the dosimetric effects of different aperture shape controller (ASC) parameters based on the Halcyon 3.0 accelerator in the hippocampal avoidance-whole brain radiotherapy (HA-WBRT) plans.Methods:This study enrolled 13 patients treated with WBRT using a Halcyon 3.0 accelerator at the Department of Radiotherapy of the Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine. According to different aperture shape controller (ASC) parameters, the HA-WBRT plans were divided into six groups, namely non, very low, low, moderate, high, and very high ASC settings, marked by AO, AVL, AL, AM, AH, and AVH, respectively. This study presented a statistical evaluation of the effects of different ASC parameters on conformity index (CI), homogeneity index (HI), radiation doses to the hippocampus and other organs at risk, and the plans’ execution efficiency. Furthermore, using two dose verification tools, namely ArcCHECK and Portal Dosimetry, this study delivered a comprehensive analysis of the differences in beam delivery precision of the plans with different ASC parameters.Results:The six groups all met the requirements for clinical treatment. They had similar CI and HI values, with no statistically significant differences ( P > 0.05). The AVH group showed better protection effects on organs at risk. Compared to the control group, the AVL group showed lower Dmax of brainstems but higher Dmax of chiasma opticum ( F = 6.26, 8.04, P < 0.05). Compared to the control group, the AH group showed lower Dmax of eyeballs but higher Dmax of optic nerves ( F = 2.04, 1.37, P < 0.05). In contrast, the AVH group exhibited lower Dmax of brainstems, eyeballs, and lens than the control group ( F = 6.26, 2.04, 2.02, P < 0.05). No statistically significant differences were observed in dosimetric indices of other organs at risk ( P > 0.05). As verified using ArcCHECK and Portal Dosimetry, the γ passing rates of the six groups were over 98% at 2%/2 mm and 100% at 3%/3 mm. The overall γ passing rates verified using ArcCHECK were lower than those verified using Portal Dosimetry. The maximum difference in the monitor unit among the six groups was less than 15, and these groups did not show significant differences in terms of execution efficiency. Conclusions:The HA-WBRT plans based on the Halcyon 3.0 accelerator can meet the requirements for clinical treatment. Different ASC parameters can significantly optimize the dosimetric parameters. Among them, the AVH parameters can highly reduce the radiation dose to organs at risk. Furthermore, different ASC parameters show insignificant effects on beam delivery precision and plan execution efficiency, meeting the verification standards for clinical therapeutic doses.
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Objective:To study the effects of poly adenosine diphosphate ribose polymerase (PARP) inhibitors niraparib and pamiparib on the radiosensitivity of breast cancer cell lines MCF-7 and MDA-MB-436, and to explore its mechanism.Methods:MCF-7 and MDA-MB-436 cells were divided into control group, niraparib group, pamiparib group, radiation group, combination group treated with niraparib and radiation, and combination group treated with pamiparib and radiation, respectively. The effects of drugs on cell proliferation and radiosensitivity were measured by CCK-8 assay and colony formation assay, respectively. The effect of drugs combined with radiation on cell cycle and apoptosis were detected by flow cytometry. Immunofluorescence method was used to detect the changes of γ-H2AX focal number of cells. The expressions of FANCG, Bax and Bcl-2 mRNA and protein were detected by qPCR and Western blot, respectively.Results:Both niraparib and pamiparib inhibited the proliferation of breast cancer cells MCF-7 and MDA-MB-436 in a time-dose dependent manner. With the increase of irradiation dose, D0, Dq, SF2 value of MCF-7 and MDA-MB-436 cells decreased, and SER D0 and SER Dq value increased. Compared with control group, the percentages of cells in G 2/M phase were increased ( tMCF-7=41.66, 44.08, P<0.05; t436=24.69, 18.91, P<0.05), the percentage of cells in G 0/G 1 phase were decreased ( tMCF-7=8.67, 29.61, P<0.05; t436=26.39, 29.12, P<0.05), and the cell apoptosis rate was significantly increased ( tMCF-7=11.17, 11.71, P<0.05; t436=42.68, 15.89, P<0.05) in the combination group. Compared with control group, the number of γ-H2AX foci of MCF-7 cells in the radiation group and combination group treated with niraparib and radiation increased significantly at 2 h after irradiation ( t=8.89, 21.72, P<0.05). At 24 h after irradiation, the number of γ-H2AX foci basically returned to normal level in the radiation group but remained at a higher level in the combination group ( t=8.82, P<0.05). Compared with control group, the expressions of FANCG and Bcl-2 mRNA decreased ( tFANCG=14.07, P<0.05; tBcl-2=29.21, P<0.05), the expression of Bax mRNA increased ( t=8.90, P<0.05), and the expression of FANCG and Bcl-2 proteins decreased ( tFANCG=7.09, P<0.05; tBcl-2=10.24, P<0.05), while the expression of Bax protein increased ( t=2.90, P<0.05) in the combination group. Conclusions:PARP inhibitors niraparib and pamiparib can increase the radiosensitivity of breast cancer MCF-7 and MDA-MB-436 cells probably through down-regulating the expression of FANCG in FA-BRCA pathway, up-regulating apoptosis-related genes and inhibiting DNA damage repair.
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Objective To analyze tissue vascular endothelial growth factor receptor 1 (VEGFR-1)and VEGFR-2 and their soluble form (sVEFGR-1 and sVEGFR-2) in the plasma in patients with preeclampsia,and to explore its clinical significance.Methods sVEGFR-1 and sVEGFR-2 expressions in plasma of normal pregnancy women and preeclampsia patients were detected by enzyme-linked immunosorbnent assay (ELISA) ; VEGFR-1,VEGFR-2,sVEGFR-1 and sVEGFR-2 mRNA expressions of normal pregnancy women and preeclampsia patients in placenta were detected by reverse transcription-polymerase chain reaction (RT-PCR).Results ELISA results showed that the level of sVEGFR-1 in plasma of normal control group before and after delivery was (12.33 ± 1.52) ng/ml and (4.55 ± 0.31) ng/ml,respectively,while that of preeclampsia group was (77.25 ± 9.47) ng/ml and (8.13 ± 0.74) ng/ml,respectively; the differences between before and after delivery in the two groups were of statistical significance.The level of sVEGFR 2 in plasma of normal control group before and after delivery was (8.74 ± 1.24) ng/ml and (6.43± 0.55) ng/ml,respectively,while that of preeclampsia group was (5.69 ± 0.75) ng/ml and (4.96 ±0.67) ng/ml,respectively.RT-PCR results were consistent with ELISA results.Conclusions Rapid decrease of plasma sVEGFR-1 and continuously low-level expression of plasma sVEGFR-2 indicated that VEGFR-1 might be closely related to preeclampsia,and decrease of plasma sVEGFR-2 in preeclampsia women might be taken as a marker of endothelial cell function disorder.
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Objective To investigate the causes and time distribution of trauma in prehospital patients. Methods The data of 2 055 trauma patients of our department admitted from January 2003 to March 2005 were analyzed. Results ① The mortality was 1.9%. ②723 patients (35.2%) were common trauma,and 32 had falling injuries (4.4%) with 18 dead including 12 at scene and 6 in emergency room. ③1 332 were Traffic accidents (64.8%) including 13 dead associated with bike , electric bicycle and motorbike. At the same time, there were 566 patients from 18:00 to 24:00 including 298 patients(52.7%) for the drivers after drinking. Conclusion Falling injuries and traffic accidents were the most important cause for death, especially in building spot . So we should enhance the security education for workers in these companies and limit the speed of electric bicycle for the increasing injury and mortality in traffic accidents . Driving after drinking at night should be prohibited too.