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  • 28 June 2010 Volume 19 Issue 2
      
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  • Investigation on Medical Exposure of X-ray Computed Tomography During the Tenth and the Eleventh Five-year Plan in Shanghai
    LU He-qing,ZHUO Wei-hai,Gao Lin-feng,et al
    2010, 19(2): 129-131. https://doi.org/10.13491/j.cnki.issn.1004-714x.2010.02.014
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    Objective To grasp the present status and the development trend on the application frequency of medical exposure from X-ray computed tomography during the tenth and the eleventh five-year plan in Shanghai.Methods The general status on medical application of X-ray CT scanners in Shanghai was investigated, and the annual numbers of head and body examinations in all hospitals were separately surveyed.The application frequency of medical exposure from X-ray CT was calculated based on the annual resident population released by Shanghai Statistics Bureau.Results A total of 151 sets of medical X-ray CT scanners were used in 101 hospitals of Shanghai in 2007.The application frequency of medical X-ray CT examinations kept increasing during the periods of the tenth and the eleventh five-year plan in Shanghai.The total frequency of X-CT examinations was 128.16‰ in 2007, with 66.94 and 61.22 examinations for head CT and body CT examinations, respectively.The annual frequency of X-CT examination accounts 12.8% of the total diagnostic X-ray procedures.Conclusion Compared with the data surveyed during the period of the ninth five-year plan, both the number of hospital possessing X-ray CT scanners and their application frequencies obviously increased during the period of the tenth and the eleventh five-year plan in Shanghai The examination ratio of X-ray CT application to the total diagnostic X-ray procedures significantly raised.And it is the main reason for the increased collective dose of the public.
  • A Study of the Expression of Bcl-2 and Bax in Rat Hearts Induced by Electromagnetic Radiations
    DOU Yan,WANG De-wen,ZHANG Min-feng,et al
    2010, 19(2): 132-134. https://doi.org/10.13491/j.cnki.issn.1004-714x.2010.02.056
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    Objective To study contrastly the variation of the expression of Bcl-2 and Bax protein in rat hearts induced by three kinds of Band Electromagnetic Radiations [X-band、S-band and Electromagnetic pluse (EMP)]and investigate the possible mechanism of apoptosis.Methods 180 healthy Wistar rats were randomly divided into four groups:a control group (n=36) and three experimental groups (n=48) respectively treated with X-band、S-band high power microwave and EMP.At different time points (6 hours, 1、3、7、14、28 days, 6 months, 12 months), the rats were killed after irradiated.We observed the pathological changes, examined the expression of Bcl-2 and Bax protein by using immunohistochemical technique and study the rule of change quantitatively by using imagine analysis technique.Results The injury of rat hearts was more and more serious at 6 hours-7 days:cardiomyofilaments were deranged;Glycogen were dicreased;Purkinje cells lysis;martix swelling and exudative serous.The expression of Bax and Bcl-2 protein was both stronger than the control group's (P<0.05).It means apotosis increase.The injured hearts showed resumptive at 14-28 days, and returned to normal progressively at 6-12 months.Conclusion Apoptosis might play an important role in the process of hearts injury induced by electromagnetic radiations and was relative to the expression of Bcl-2 and Bax protein.The injury grades are X > S > EMP.
  • Total Body Irradiation Planning System Based on CT Images
    LIN Xiao-lei, XU Hai-rong
    2010, 19(2): 135-137. https://doi.org/10.13491/j.cnki.issn.1004-714x.2010.02.015
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    Objective To design a new Total Body Irradiation planning system (TBI-Plansys) based on CT images.Methods A description of the material and method in the dosimetrical procedure is included as it constitutes the basis of the proposed dose calculation algorithm.Microsoft Visual C++ was used to analyze CT images for useful information and to calculate the dose of patients.The dose distribution displayed on CT images was processed by the dose distribution calculation methods.VTK technology was used in the 3D display in the system.Results TBI-Plansys use patient CT data to calculate the absolute and relative dose distributions along midline, the transversal axis at the specification point and on transverse sections.The system also calculates the appropriate thickness of bolus and shielding to modify undesired dose distributions.Conclusions CT calculations by TBI-Plansys allow us to detect undesired distributions which may go unnoticed by calculations at only some specific points.The system has shown clear advantages for routine clinical use as it generates more detailed and accurate information than manual calculations and diminishes the time requirements.
  • The Dose-response Relationship of T-cell Receptor Gene Mutation of Rat Peripheral Blood Lymphocytes Induced by X-ray
    SHI Yan, LIU Wei, HOU Dian-jun, et al
    2010, 19(2): 138-139. https://doi.org/10.13491/j.cnki.issn.1004-714x.2010.02.016
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    Objective To investigate the does-response relationship of T-cell receptor from rat peripheral blood lymphocyte induced by X-ray.Methods Freshly isolated peripheral lymphocytes from rat were irradiated with X-ray ranged from 0 Gy to 3 Gy and cultured with phytohemagglutinin Concanavalin A and interleukin-27days, The mutant frequencies of TCR gene were detected by flow cytometry.Results TCR genes mutation increases with the dose incense in the cultured the rat lymphocytes 7 days and it exists favourable dose-response relationship.Data were found to be fitted out optimal by a quadratic polynomial dose-response modle, which could be described by regression equation:TCRMF=TCRMF=1.615+9.979D+1.712D2 (F=146.781, P<0.01, Radj2=0.867).Conclusion The favourable dose-response relationship between TCRMF induced by X ray and dose can be found from this study.
  • Discussion of Feasibility to Carry out Intensity Modulated Radiation Therapy in Conventional Medical Electron Linear Accelerator Treatment Rooms
    YANG Hai-you, LIU Li-ping, LIANG Yue-qin, et al
    2010, 19(2): 140-143. https://doi.org/10.13491/j.cnki.issn.1004-714x.2010.02.017
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    Objective To investigate the feasibility about the shielding effect of conventional mdical electron linear accelerator treatment in the existing rooms to carry out intensity modulated radiation therapy (IMRT).Methods The estimation model given in NCRP REPORT No.151-"Structural Shielding Design and Evaluation for Megavoltage X-and Gamma-Ray Radiotherapy Facilities" is adopted by linking instances, which presents the calculation methods on radiation level at the ambience of megavoltage medical electron linear accelerator treatment room.Results The radiation level, as well as the additinal annual effect dose of occupational and public at the ambience of accelerator treatment room, in crease to a certain extent, when convontional medical electron linear accelerator treatment room;are used to carry out IMRT.Conclusion It is necessary to make environmental impact assessment for conventional medical electron linear accelerator treatment rooms, which will be used to execute IMRT.
  • The Study of Ionizing Radiation on Proliferation of Mouse Spleen B Lymphocyte
    ZHANG Heng, WU Hong-ying, LI De-guang, et al
    2010, 19(2): 143-144. https://doi.org/10.13491/j.cnki.issn.1004-714x.2010.02.001
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    Objective To study the effect of ionizing radiation on mouse spleen B lymphocytes proliferation and the protective effect by inhibiting p38-MAPK signal transduction pathway.Methods To observe the ionizing radiation with different doses on mouse spleen cells in vivo and vitro and before and after radiation, inject SB203580 on mice and analyze the protective or therapeutic effect on them.Results In vitro, ionizing radiation can impair mouse spleen cells proliferation, while in vivo, low doze ionizing radiation can enhance mouse spleen cell proliferation and high dose can hurt it.Exposed in sublethal dose ionizing radiation, mouse spleen could be protected by using SB203580.Conclusion Inhibting p38-MAPK pathway can protect mouse spleen cells from being damaged by ionizing radiation.
  • Experimental Research of Effects of Extremely Low Frequency Electromagnetic Fields on Immune Function of BALB/c Mice
    ZHU Shi-zhong
    2010, 19(2): 145-147. https://doi.org/10.13491/j.cnki.issn.1004-714x.2010.02.057
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    Objective To explore the effects of extremely low frequency electromagnetic fields on BALB/c mice immune function.Methods BALB/c mice were exposed to extremely low frequency electromagnetic radiation devices, and then their non-specific immune function, including the thymus, spleen and phagocytic index were measured.Humoral immune function, serum levels of IgG antibodies were detected by using the ELISA method.Results The three different dose groups, (1.0mT/, 4.5 mT and 9.0mT) in this study, were compared with the control groups.The thymus and spleen index of low, medium-dose treatment groups at 8 weeks and 12 weeks were all higher than that of the control group, but it is lower in the high-dose treatment group than in the control group.The detection of phagocytic index and humoral immune function was in a similar regularity.Conclusion The effects of extremely low frequency electromagnetic fields on BALB/c mice immune function at thelow and medium-dose were shown to be enhanced and the role of high-dose exposure was inhibited.This study can provide valuable data for the development of electromagnetic radiation on human health standards.
  • The Analysis of Skyshine Caused by X-γ Ray
    SONG Zhuo-ren, SU Qin, ZHU Ying-jun
    2010, 19(2): 147-150. https://doi.org/10.13491/j.cnki.issn.1004-714x.2010.02.018
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    Objective To analyse the variation of the radiation dose in the atmosphere outside of the shielding enclosures caused by X-γ ray's skyshine and the monitoring method in daily radiation monitoring.Method By using the monte carlo softwave mcnp4c for calculating many kinds of the skyshine models.Results Giving the shandow radius's empirical formula of the large space.Conclusion The variation of the radition dose in the atmosphere outside of the shielding enclosures is not monotonously decreasing, it will get the maximal value when reaching the shandow radius of the shielding enclosures.Monitoring at the shandow radius is suggested.
  • Dose Estimation of Two Victims in a Severe Radiation Accident By Using Tooth Enamel
    YANG Ying-jie, GAO Gang, SU Xu
    2010, 19(2): 150-151. https://doi.org/10.13491/j.cnki.issn.1004-714x.2010.02.019
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    Objective To estimate the exposed dose levels of 2 two victims, who died one month after they were accidentally irradiated by Cobalt-60.Methods Three teeth were extracted from 2 victims.The signal intensities of separated enamel samples were measured with ESR spectrometer.The accumulated exposed doses were reconstructed according to a calibration curve established using Cobalt-60 γ-rays.Results A calibration curve between signal intensity and exposed dose was established.The estimated doses of 3 teeth were 26.1~29.4Gy, for victim A, 14.9~18.3Gy and 15.2~18.5Gy for victim B.The doses are close to the result of the other Laboratory.Conclusion The application of ESR dosimetry in human tooth enamel could provide important information for a dose estimation of victims exposed to heavy doses of radiation.
  • Comparison of Radiosensitivity of Immune Cells in Three Kinds of Mice
    WU Hong-ying, WANG Yue-ying, ZHANG Heng, et al
    2010, 19(2): 152-153. https://doi.org/10.13491/j.cnki.issn.1004-714x.2010.02.058
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    Objective To compar the radiosensitivity of thymus (Th), spleen (Sp) cells between IRM-2, ICR and 615 mouse and explor the immunological and radiation resistance mechanisms of IRM-2 mice.Methods The peripheral blood cytotype was determined by flow cytometry.By PA Law (FITC-Annexin V and PI labeling), the apoptosis of Th and Sp cells was detected after irradiation.Results CD4/CD8 ratio of IRM-2 mice was lower than that of ICR and 615 mice;CD25/CD4 ratio was higher than 615 mice (P<0.05), lower than ICR mice;apoptosis rate of Sp cells exposed to 0、1、4 Gy γ-ray was lower than ICR and 615 mice, the difference was of statistical significance (P<0.05);apoptosis rate of Th cell was lower than ICR and 615 mice, especially 615 mice in 4Gy irradiated group (P<0.01).Conclusion The apoptosis rate of IRM-2 was lower than that of ICR and 615 mice after irradiation.Th and Sp cells of IRM-2 mice were not sensitive to radiation.