1.Estimation of patient doses in paediatric cardiovascular interventional radiology under specific exposure conditions
Xin CHEN ; Weiyuan ZHANG ; Weihai ZHUO
Chinese Journal of Radiological Medicine and Protection 2021;41(3):199-204
Objective:To estimate the organ doses and effective doses to different-age children during cardiovascular interventional radiological procedures under some specific exposure conditions, and explore the main influencing factors on the doses.Methods:Based on the paediatric reference computational phantoms recommended in the ICRP Publication 143, several specific exposure models of cardiovascular intervention were built, and the Monte Carlocook MCNPX 2.7.0, was used to calculate the organ doses and effective doses for 1-, 5-, 10- and 15-year-old children. To validate the simulation result , an experiment was implemented by putting the thermoluminescent dosimeters in a 5-y old phantom (ATOM 705-D) manufactured by the CIRS Inc. in the USA.Results:Both the height and weight of the reference children for 1-, 5- and 10-year-old provided for by Chinese national standards are nearly in consistency with those recommended by ICRP, and even for the 15-year-old, the maximum relative deviations of the height and weight are only -1.9% and -5.7%, respectively. Under the exposure condition where the focal spot to image receptor distance (SID) was 90 cm, the length of square field of view (FOV) was 30 cm with a dose area product (DAP) of 45 Gy·cm 2, the relative deviations between simulated and measured doses to main organs/tissues within the irradiation filed were within ±6.7%. Under the same exposure conditions, the younger the children, the larger the organ doses and effective doses, and the effective doses could vary by a factor of about 5 among the 4 age groups. The conversion coefficient between the organ dose and the value of DAP was not only closely related to the age of children, but also affected by the FOV. Conclusions:In combination with the paediatric reference computational phantoms and the exposure models of cardiovascular intervention, the Monte Carlo method can be used to calculate the doses to children undergoing cardiovascular interventional radiological procedures. The information on the values of DAP and FOV as well as the directions of projection are needed for more accurate estimation of the exposure doses.
2.Effect of Taohong Siwu DecoctionⅡon Inhibiting the Agiogenesis and KDR/FLK-1 Expression
Xiaoyu XU ; Shumei WANG ; Weihai CHEN ; Gang CHEN
Traditional Chinese Drug Research & Clinical Pharmacology 2000;0(05):-
Objective To study the anti-agiogenesis effect of Taohong Siwu Decoction Ⅱ(THSDⅡ)and to explore its mechanism.Methods Chicken Chorioallantoic Membrane(CAM)assay was used to study the anti-agiogenesis action of THSDⅡin vivo.MTT assay was used to investigate its effect on the proliferation of human umbilical vein vascular endothelial cells ECV304 in vitro.Immunohistochemistry assay was used to observe its effects on the expression of KDR/FLK-1 in endothelial cells and the amount of micro-vessel density(MVD)in mice with B16 melanoma.Results THSDⅡ at the dosages of 1 g / mL and 2 g / mL could obviously inhibit agiogenesis in the CAM(P
3.Analysis of GJB2, SLC26A4, GJB3 and 12S rRNA gene mutations among patients with nonsyndromic hearing loss from eastern Shandong.
Shiyu SUN ; Linyuan NIU ; Jinjun TIAN ; Wei CHEN ; Yanna LI ; Ningning XIA ; Caining JYU ; Xiaoli CHEN ; Chunxiao ZHANG ; Xinqiang LAN
Chinese Journal of Medical Genetics 2019;36(5):433-438
OBJECTIVE:
To explore the characteristics of mutations of four common pathogenic genes (GJB2, SLC26A4, GJB3 and 12S rRNA) among patients with nonsyndromic hearing loss (NSHL) from eastern Shandong.
METHODS:
Peripheral blood samples of 420 NSHL patients were collected, and a hereditary-deafness-gene microarray was used to detect GJB2 c.235delC, c.299-300delAT, c.35delG and c.176del16 mutations, GJB3 c.538C>T mutation, SLC26A4 c.2168A>G and c.IVS7-2A>G mutations, and 12S rRNA c.1555A>C and c.1494C>T mutations. For patients carrying single heterozygous mutations, the coding regions of the above genes were analyzed with Sanger sequencing.
RESULTS:
The results of the microarray assay and Sanger sequencing showed that 84 patients (20.00%) carried GJB2 mutations, with c.235delC (16.43%) and c.299-300delAT (7.86%) being most common. Seventy-five patients (17.86%) carried SLC26A4 mutations, for which c.IVS7-2A>G accounted for 15.71%. In addition, 5.95% of patients carried 12S rRNA mutations. Only one patient was found to carried GJB3 mutation (c.538C>T).
CONCLUSION
Common pathogenic mutations for NSHL in eastern Shandong included GJB2 c.235delC and SLC26A4 c.IVS7-2A>G. Of note, 5.95% of patients were due to 12S rRNA m.1555A>G mutation, which gave a frequency greater than other regions of China.
China
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Connexin 26
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Connexins
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DNA Mutational Analysis
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DNA, Mitochondrial
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Deafness
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Genes, rRNA
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Hearing Loss
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Humans
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Mutation
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RNA, Ribosomal
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Sulfate Transporters
4.Development of a software for predicting the effects of nuclear and radiological terrorism events in city areas
Lijuan LUO ; Bo CHEN ; Weihai ZHUO ; Shuyu LU
Chinese Journal of Radiological Medicine and Protection 2011;31(2):206-209
Objective To develop a new software system that cau directly display the predicted results on an electronic map,in order to get a directly perceived understanding of the affected areas of nuclear and radiological terrorism events in city areas.Methods Three scenarios of events including spreading radioactive materials, dirty bomb attack,and explosion or arson attacks on the radiation facilities were assumed.Gaussian diffusion model was employed to predict the spread and deposition of radioactive pollutants,and both the internal and external doses were estimated for the representative person by using the corresponding dose conversion factors.Through integration of the computing system and Mapinfo geographic information system(GIS),the predicted results were visually displayed on the electronic maps of a city.Results The new software system could visually display the predicted results on the electronic map of a city, and the predicted results were consistent with those calculated by the similar software Hotspot(R)The deviation between this system and Hotspot was less than 0.2 km for predicted isoplethic curves of dose rate downwind.Conclusions The newly developed software system is of the practical value in predicting the effects of nuclear and radiological terrorism events in city areas.
5.Organ dose evaluation for CT scans based on in-phantom measurements
Haikuan LIU ; Weihai ZHUO ; Bo CHEN ; Yanling YI ; Dehong LI
Chinese Journal of Radiological Medicine and Protection 2009;29(2):221-224
Objective To explore the organ doses and their distributions in different projections of CT scans.Methods The CT values were measured and the linear absorption coefficients were derived for the main organs of the anthropomorphic phantom to compare with the normal values of human beings.The radiophotoluminescent glass dosimeters were set into various tissues or organs of the phantom for mimic measurements of the organ doses undergoing the head,chest,abdomen and pelvis CT scans,respectively.Results The tissue equivalence of the phantom used in this study was good.The brain had the largest organ dose undergoing the head CT scan.The organ doses in thyroid,breast,lung and oesophagus were relatively large in performing the chest CT scan,while the liver,stomach,colon and lung had relatively hrge organ doses in abdomen CT practice.The doses in bone surface and colon exceeded by 50 mGy in a single pelvis CT scan.Conclusions The organ doses and their distributions largely vary with different projections of CT scans.The organ doses of colon,bone marrow,gonads and bladder are fairly large in performing pelvis CT scan,which should be paid attention in the practice.
6.The study on effects of indoor air filtration on radon exposure to residents
Liping HE ; Bo CHEN ; Chao ZHAO ; Weihai ZHUO
Chinese Journal of Radiological Medicine and Protection 2016;36(9):688-693
Objective To evaluate the influence of indoor air filtration by air purifier on the behavior of indoor radon progeny and estimate its effects on indoor radon exposure to residents.Methods The concentrations of indoor radon progeny with and without the air filtration were calculated by the theoretical model developed in this study.Based on the dose conversion factors of attached and unattached radon progeny,the mitigation effects of indoor radon exposure due to the air filtration were estimated.Verification experiments were conducted in an airtight room.Results With the air filtration rate increased,the removal efficiency of indoor radon progeny would appear more obvious.For an airtight room with its initial aerosol concentration of 10 000 cm-3,the concentration of total radon progeny would decrease by more than 90% when the air filtration rate exceeded 10 h-1.But the concentrations of indoor unattached radon progeny would increase by using the air purifier in different extents.The variations of radon progeny concentrations and the decrease of internal doses were closely related to the filtration rate of air purifier.With the air filtration rates increased,the mitigation effects would be better and faster.The internal dose would reduce by more than 70% when the filtration rate exceeded 5 h-1.Conclusions Although the indoor concentration of unattached radon progeny will increase by using the air purifier,it is still effective in reducing the exposure dose to residents due to the inhalation of radon progeny.
7.The changes and significance of blood fat and myocardial enzymes in patients with hypothyroid myopathy before and after substitutional treatment
Weihai QIU ; Chao CHEN ; Lizhen MENG ; Feng WEI
Chinese Journal of Primary Medicine and Pharmacy 2011;18(17):2327-2328
Objective To observe the changes and significance of blood fat and myocardial enzymes in patients with hypothyroid myopathy before and after substitutional treatment.Methods The levels of TC, TG, LDL-C,AST, LDH, HBDH and CKMB were detected in 72 cases with hypothyroid myopathy patients before and after substitutional treatment and 60 healthy controls. Results The levels of TC,TG and LDL-C in hypothyroid myopathy patients before substitutional treatment were significantly higher than those in control group ( all P < 0. 05 ), and then significantly low after treatment,which had no significant difference with control group( all P >0. 05). The levels of AST,LDH,HBDH and CKMB in hypothyroid myopathy patients before substitutional treatment were significantly higher than those in control group( all P < 0. 05 ) ,and then significantly low after treatment,which had no significant difference with control group( all P >0. 05). Conclusion The levels of blood fat and myocardial enzymes were significantly increased in hypothyroid myopathy patients, and recovery to normal after substitutional treatment.
8.A survey and analysis of dose level for adults undergoing posteroanterior chest X-rays photography in Shanghai
Peng LI ; Linfeng GAO ; Weihai ZHUO ; Bo CHEN
Chinese Journal of Radiological Medicine and Protection 2013;(1):68-71
Objective To survey the current dose level for adults undergoing posteroanterior (PA) chest X-ray photography in Shanghai,and to analyze the main factors affecting the dose level.Methods The thermoluminescence dosimeters (TLDs) were deployed to measure entrance surface dose (ESD) in the center of radiated fields.According to the numbers of three types of X-ray equipment and their distribution among different grade hospitals in Shanghai,the ESDs were surveyed for 1032 adults undergoing examination of PA chest X-ray photography from 2008 to 2010,and the relevant information was also recorded.The differences of the mean ESDs among different grade hospitals,equipment types and photographic parameters were statistically analyzed.Results The arithmetic mean of the ESDs for adults undergoing examination of PA chest X-ray photography in Shanghai was 0.23 mGy,and the 75th percentile value was 0.29 mGy,which were all below the current China diagnostic reference level (0.40 mGy).The averaged ESDs were significantly correlated with the grade of hospital,the equipment types and the photographic parameters.Conclusions Compared with the value in the last century,the ESD for adults undergoing PA chest X-ray photography in Shanghai obviously decreases,and there are the potentials for further reduction.
9.Estimation of the entrance surface dose from the dose indicator in computed radiography system
Tianjun MA ; Bo CHEN ; Weihai ZHUO ; Haikuan LIU
Chinese Journal of Radiological Medicine and Protection 2013;33(4):423-426
Objective To study the relationship between the dose indicator of computed radiography (CR) and the entrance surface dose (ESD),and to build a model for estimating ESD based on this relationship.Methods Taking Kodak CR system as the research object,a theoretical model for estimating the ESD was established according to theoretical derivations,and the key parameters in the model were determined through experiments in a CR system.Further experiments in another CR system were also conducted to verify the model.Results The ESDs were not only dependent on the dose indicator provided by the CR system,but also influenced by other factors,such as tube potential,patient's body thickness and energy response of the imaging plate.The estimation results of the model agreed well with the experiment results,and the relative deviation was confirmed within 20%.Conclusions The dose indicator based model can provide a relatively fast and easy way for evaluating the doses of patients undergoing X-ray diagnoses with the CR system.
10. Research progress on urogenital function preservation in extralevator abdominoperineal resection
Huanhu ZHANG ; Chen SUN ; Shaowei SUN ; Shengbo SUN
Chinese Journal of Gastrointestinal Surgery 2020;23(1):92-95
Extralevator abdominoperineal excision (ELAPE) has been suggested to potentially improve oncological outcomes in advanced low rectal cancer patients. However, the urogenital function impairment as one of the main complications deteriorates the quality of life in these patients. The key point to prevent urogenital function impairment is to avoid autonomic nerve injury, including the superior and inferior hypogastric nerve plexus and neurovascular bundle. Three areas should be especially focused during surgery, including the posterolateral aspect of the prostate during the separation of the rectum from prostate, the lateral wall of ischioanal fossa and the area in front of anal canal. Previous presumption supposed that extended resection, though promoting oncologic outcomes, might lead to enlarged injury to surrounding vessels and nerves that deteriorated patients′ urogenital function. But recent studies show that postoperative urogenital function outcomes of rectal cancer patients who underwent ELAPE are not inferior to conventional APE after the induction of minimal invasive approaches including laparoscopic and robotic surgery. Their quality of life can be comparable with patients who underwent conventional APE, and are even better in some particular area. Moreover, as further improvement of ELAPE procedure has been made, the concept of individualized ELAPE addressed the importance of personalized surgical procedure based on tumor stage and location, dedicating to avoid injury to vessels and nerves through preserving more surrounding tissues. Urogenital function outcomes, as part of postoperative outcomes, get more and more attention in recent years. We review current studies on urogenital function after ELAPE from anatomy to clinical research, in order to raise surgeons′ attention of nerve preservation technique and to improve their understanding of ELAPE procedure.