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Objective To analyze the factors influencing the levels of occupational exposure in medical radiation workers in China, and to provide a scientific basis for determining the key points of radiation protection in the medical sector. Methods The individual monitoring data on occupational external exposure in medical radiation workers in 2021 were collected from the “National Individual Dose Registry”. The Chi-squared test and logistic regression were used to analyze the factors influencing the levels of occupational exposure in medical radiation workers. Results The Chi-squared test showed that gender, occupational category, medical institution category, region, number of radiation workers per thousand population, and regional per capita GDP were significantly associated with occupational exposure in medical radiation workers exceeding the annual effective dose of 5 mSv and an annual effective dose limit of 20 mSv (χ2 = 21.456−262.329, 7.601−78.650, P < 0.05). The logistic regression analysis further showed that gender, occupational category, region, and number of radiation workers per thousand population were factors influencing the occupational exposure in medical radiation workers exceeding the annual effective dose of 5 mSv (χ2 = 14.621−170.857, P < 0.05); gender, occupational category, region, and regional per capita GDP were factors influencing the occupational exposure in medical radiation workers exceeding the annual effective dose of 20 mSv (χ2 = 5.401−48.709, P < 0.05). Conclusion Male radiation workers in interventional radiology and in central China have high risks of exceeding annual effective doses of 5 and 20 mSv. Moreover, high number of radiation workers per thousand population and regional per capita GDP are associated with low risks. Medical institutions should maintain a sufficient number of radiation workers and strengthen training on radiation protection knowledge for male and interventional radiology workers to enhance their radiation protection awareness. Investigation of the factors contributing to the high occupational exposure in central China should be intensified, and targeted effective measures should be conducted to reduce the occupational exposure in medical radiation workers.
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Objective:To ascertain the levels of individual doses to radiation workers arising from occupationally external exposure in China in 2017, with an aim to provide basic data and scientific basis for prevention and control of occupational radiation sickness.Methods:Data on individual doses to monitored workers engaged in medical and industrial applications of radiation sources were collected through National Individual Dose Registry, with statistical analysis being carried out using Kruskal-Wallis H test, Mann-Whitney U test and Bonferroni method. Results:A total of 361 727 radiation workers were investigated in 2017, of which 81.6% was from medical application and 18.4% from industrial application, respectively. The average annual effective dose from medical and industrial applications were 0.353 and 0.270 mSv, respectively, with the former significantly higher than the latter ( Z=48.547, P<0.05). Furthermore, a statistically significant difference was seen in the average annual effective dose for each occupational category of medical application ( H=1 136.217, P<0.05), suggesting that the dose values for the monitored workers in nuclear medicine and interventional radiology were significantly higher than for other four medical categories ( Z=2.877-26.967, P<0.05). These dose values for the radiation workers was 0.361 mSv in tertiary hospitals, 0.397 mSv in secondary hospitals, and 0.308 mSv in primary and unrated hospitals, respectively. The dose values for the monitored workers in industrial radiography and well logging were significantly higher than for other five industrial categories of industrial applications ( Z=4.172-36.908, P<0.05). Conclusions:The average annual effective doses to the of monitored workers meet the relevant national standards. The exposure doses to the workers in nuclear medicine, interventional radiology, industrial radiography and well logging are relatively high. The necessary measures and devices for radiation protection should be further strengthened to reduce occupational exposure of workers.
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Objective@#To investigate the efficacy of massage combined with microwave therapy in treating Children's bronchial pneumonia with syndrome of deficiency of lung-spleen Qi.@*Methods@#Two hundred forty-four bronchial pneumonia Children were selected in our hospital and randomly divided into the control group and the observation group with 122 cases in each group referring to random number table. The control group was administered with the routine treatment. Based on the control group, the observation group received the massage and microwave therapy. The course was 2 week for both groups. The syndrome scores of traditional Chinese medicine were performed before and after treatment, and the disappearance of gasping, antipyretic, disappearance of moist rale in the lungs, and absorption time of chest X-ray were observed and recorded. the flow cytometry was used to detect peripheral blood levels of CD4+ and CD8+, and serum levels of IL-6 and IL-8 were detected by ELISA. The clinical effect rate was evaluated.@*Results@#The total effective rate was 97.5% (118/121) in the observation group and 91.7% (110/120) in the control group,with statistically significant differences (χ2=4.406, P=0.044). After treatment, the scores of cough, phlegm, shortness of breath, pale face, fatigue, spontaneous perspiration, poor appetite in the observation group were significantly lower than those in the control group (t value were 10.008, 11.529, 11.778, 12.043, 11.309, 10.128, 11.008, P<0.01), and elapsed time of gasping, antifebrile time, disappear time of lung moist crackles, absorption time were significantly earlier than the control group (t value were 15.121, 10.099, 18.441, 14.310, P<0.01). After 2 week’ treatment, the scores of symptoms of deficiency of lung-spleen Qi in the observation group were significantly lower than those of control group (P<0.01). Compared with the control group, the duration of wheezing and antipyretic, duration of lung dampness and chest X-ray absorption in the observation group were significantly decreased (P<0.05). The total effective rate of the observation group was 97.52%, which was significantly higher than the control group 92.67% (P<0.05). After 2 week treatment, the CD4+ (41.03% ± 4.55% vs. 33.52% ± 3.95%, t=14.011) in the observation group was significantly higher, CD8+ (22.71% ± 2.83% vs. 26.65% ± 3.05%, t=10.061) was significantly lower than the control group, serum levels of IL-6 (28.13 ± 3.63 ng/L vs. 40.09 ± 4.61 ng/L, t=14.890) and IL-8 (21.41 ± 2.75 ng/L vs. 29.05 ± 3.61 ng/L, t=11.439) were significantly lower than the control group (P<0.01).@*Conclusions@#Massage combined with microwave therapy for the Children's bronchial pneumonia with deficiency of lung-spleen Qi syndrome can promote the improvement of symptoms, enhance the efficacy, increase the immune function and reduce inflammation level.
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Objective@#To construct a national medical radiation protection monitoring information system (NMRPMIS) based on the national radiation health information platform, support the national medical radiation protection monitoring project data reporting, and comprehensively understand the current situation of medical radiation protection.@*Methods@#According to the national radiation protection monitoring plan, laws, regulations and standards, HTML, CSS and JavaScript were used in the front end, JAVA language was used in the back end, SQL server was used in the platform database and Tomcat was used as the middleware. A data reporting and analysis system was set in the system through B/S structure, with statistical analysis of the 2017 annual monitoring data carried out.@*Results@#The business composition of the platform includes four levels: data acquisition (through various business systems), data resource integration (integration of business system public data), application, and display. The national medical radiation protection monitoring system with flexible structure, centralized information and convenient operation was implemented. The national medical radiation protection information was reported in 2017. The basic situation of radiation protection in 33 565 hospitals and the performance and protection information of 10 624 pieces of radiation diagnosis and treatment equipment were reported in 2017. A total of 95 statistical information reports were completed, describing the current situation of medical radiation protection in China from four dimensions: time, administrative geographic information, hospital level, and equipment types.@*Conclusions@#Medical radiation protection monitoring system helped achieve the design goal and successfully complete the data reporting in 2017. It provides data support for understanding the current situation of medical radiation protection and the protection management policymaking in China.
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Objective@#To construct a national radiological health information platform, in order to collect and analyze radiological health monitoring and survey data, so as to improve data utilization and ensuring technology support to radiological health.@*Methods@#In accordance with China′s relevant laws, regulations and regulations, a national radiological health information platform was designed, developed and operated in response to the needs of radiological health monitoring, scientific research and management.@*Results@#The system was initially established in 2015, consisting of five business modules: medical radiation protection, personal dose, occupational health, food radioactivity monitoring and occupational radiological disease reporting. In the past 4 years, the system has been running normally and 5 business databases have been established. More than 8 million data of monitoring and survey have been collected. More than 1 400 terminal users have good experiences and frequent interactions.@*Conclusions@#The successful construction of the national radiological health information platform not only promotes and standardizes the network direct reporting of radiological health monitoring and investigation business data, but also provides analytical and utilization tools for technical institutions/personnel on radiological health, and gradually becomes an important scientific basis and database for the development of radiological health laws, regulations and standards in China as well as for national health service.
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Objective To construct a national medical radiation protection monitoring information system (NMRPMIS) based on the national radiation health information platform, support the national medical radiation protection monitoring project data reporting, and comprehensively understand the current situation of medical radiation protection. Methods According to the national radiation protection monitoring plan, laws, regulations and standards, HTML, CSS and JavaScript were used in the front end, JAVA language was used in the back end, SQL server was used in the platform database and Tomcat was used as the middleware. A data reporting and analysis system was set in the system through B/ S structure, with statistical analysis of the 2017 annual monitoring data carried out. Results The business composition of the platform includes four levels: data acquisition ( through various business systems), data resource integration (integration of business system public data), application, and display. The national medical radiation protection monitoring system with flexible structure, centralized information and convenient operation was implemented. The national medical radiation protection information was reported in 2017. The basic situation of radiation protection in 33565 hospitals and the performance and protection information of 10624 pieces of radiation diagnosis and treatment equipment were reported in 2017. A total of 95 statistical information reports were completed, describing the current situation of medical radiation protection in China from four dimensions: time, administrative geographic information, hospital level, and equipment types. Conclusions Medical radiation protection monitoring system helped achieve the design goal and successfully complete the data reporting in 2017. It provides data support for understanding the current situation of medical radiation protection and the protection management policymaking in China.
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Objective To construct a national radiological health information platform, in order to collect and analyze radiological health monitoring and survey data, so as to improve data utilization and ensuring technology support to radiological health. Methods In accordance with China′s relevant laws, regulations and regulations, a national radiological health information platform was designed, developed and operated in response to the needs of radiological health monitoring, scientific research and management. Results The system was initially established in 2015, consisting of five business modules: medical radiation protection, personal dose, occupational health, food radioactivity monitoring and occupational radiological disease reporting. In the past 4 years, the system has been running normally and 5 business databases have been established. More than 8 million data of monitoring and survey have been collected. More than 1400 terminal users have good experiences and frequent interactions. Conclusions The successful construction of the national radiological health information platform not only promotes and standardizes the network direct reporting of radiological health monitoring and investigation business data, but also provides analytical and utilization tools for technical institutions/ personnel on radiological health, and gradually becomes an important scientific basis and database for the development of radiological health laws, regulations and standards in China as well as for national health service.
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Objective To investigate the effect of hydroxyapatite/zirconia (HA/ZrO2) scaffold by three-dimensional printing compounded with vascular endothelial growth factor (VEGF) 165 calcium alginate microsphere slow-release system on repairing femoral shaft defects in dogs.Methods The HA/ZrO2 artificial prosthesis was prepared by three-dimensional printing,and the co-culture system of slow-release system of composite VEGF 165 calcium alginate microspheres was constructed.Sixteen beagle dogs were divided into four groups according to the extent of femoral shaft interception,with four dogs in each group.Group A:no biomaterials were implanted into the middle femur of dogs after 15 mm of femur interception as blank control group;Group B:HA/ZrO2 scaffolds composite with VEGF165 calcium alginate microspheres were implanted into the middle femur of dogs after 15 mm of femur interception;Group C:the same method as Group B was adopted after 25 mm of femur interception;Group D:the same method as Group B was adopted after 35 mm of femur interception.General examination and X-ray imaging observation were taken after operation.The ability of new HA/ZrO2 gradient biocomposites to repair bone defects was evaluated by micro CT scanning,biomechanical testing,ink staining and toluidine blue staining 12 weeks after operation.Results The drug loading capacity of calcium alginate microspheres reached (23.6 ± 2.9) ng/mg,and the entrapment efficiency reached (62.4 ± 3.6) ％,showing a slow rate of release.Gross examination showed surgical incision was healed in all four groups.Postoperative X-ray imaging of experimental animals showed that nonunion was formed in Group A over time;in Group B,the artificial prosthesis was gradually filled with new bone and the boundary was blurred;in Group C,the early reaction was slower than that in Group A,and the callus passed continuously 12 weeks after operation;in Group D,new bone formation was slow,only surrounding the broken end.At 12 weeks after operation,the neonatal bone mass was (238.6 ± 19.1)mm3 in Group B,(223.3 ± 13.4) mm3 in Group C,and (110.8 ± 6.5) mm3 in Group D.There were significant differences among the three groups (P ＜ 0.05),but no significant difference was found between Group B and Group C (P ＞ 0.05).The results limit compression test at 12 weeks after operation showed no significant differences among Groups B [(49.7 ± 2.3) MPa],C [(49.81 ± 2.4) MPa] and D [(46.9 ± 3.6) MPa](P ＞ 0.05).At 12 weeks after operation,the histological sections showed that the blood vessels in Groups B and C were thickened,with obvious branches,and the surrounding new bone increased.During the period,the blood vessels were filled with vascular network.There were no obvious differences in the number and shape of blood vessels between groups.However,Group B had more new bones and blood vessel networks.New bone and small vascular networks were seen in Group D.Conclusion The hydroxyapatite/zirconia scaffold by three-dimensional printing compounded with vascular endothelial growth factor 165 calcium alginate microsphere slow-release system can repair dogs' femoral bone defect within 35 mm.
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Objective To investigate the efficacy of massage combined with microwave therapy in treating Children's bronchial pneumonia with syndrome of deficiency of lung-spleen Qi. Methods Two hundred forty-four bronchial pneumonia Children were selected in our hospital and randomly divided into the control group and the observation group with 122 cases in each group referring to random number table. The control group was administered with the routine treatment. Based on the control group, the observation group received the massage and microwave therapy. The course was 2 week for both groups. The syndrome scores of traditional Chinese medicine were performed before and after treatment, and the disappearance of gasping, antipyretic, disappearance of moist rale in the lungs, and absorption time of chest X-ray were observed and recorded. the flow cytometry was used to detect peripheral blood levels of CD4+ and CD8+, and serum levels of IL-6 and IL-8 were detected by ELISA. The clinical effect rate was evaluated. Results The total effective rate was 97.5% (118/121) in the observation group and 91.7% (110/120) in the control group,with statistically significant differences (χ2=4.406, P=0.044). After treatment, the scores of cough, phlegm, shortness of breath, pale face, fatigue, spontaneous perspiration, poor appetite in the observation group were significantly lower than those in the control group (t value were 10.008, 11.529, 11.778, 12.043, 11.309, 10.128, 11.008,P<0.01), and elapsed time of gasping, antifebrile time, disappear time of lung moist crackles, absorption time were significantly earlier than the control group (t value were 15.121, 10.099, 18.441, 14.310, P<0.01). After 2 week’ treatment, the scores of symptoms of deficiency of lung-spleen Qi in the observation group were significantly lower than those of control group (P<0.01). Compared with the control group, the duration of wheezing and antipyretic, duration of lung dampness and chest X-ray absorption in the observation group were significantly decreased (P<0.05). The total effective rate of the observation group was 97.52%, which was significantly higher than the control group 92.67% (P<0.05). After 2 week treatment, the CD4+(41.03% ± 4.55% vs. 33.52% ± 3.95%, t=14.011) in the observation group was significantly higher, CD8+ (22.71% ± 2.83% vs. 26.65% ± 3.05%, t=10.061) was significantly lower than the control group, serum levels of IL-6 (28.13 ± 3.63 ng/L vs. 40.09 ± 4.61 ng/L, t=14.890) and IL-8 (21.41 ± 2.75 ng/L vs. 29.05 ± 3.61 ng/L, t=11.439) were significantly lower than the control group (P<0.01). Conclusions Massage combined with microwave therapy for the Children's bronchial pneumonia with deficiency of lung-spleen Qi syndrome can promote the improvement of symptoms, enhance the efficacy, increase the immune function and reduce inflammation level.
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Circulating tumor DNA (ctDNA) refers to the DNA segment of the free tumor located in the peripheral circulation,which carries the biologic information derived from the tumor.In recent years,the innovation of the second generation sequencing technology has expanded the prospect of the clinical application of ctDNA analysis.Detection of ctDNA has made a great progress in the field of radiation therapy,especially in the aspect of evaluating the sensitivity of radiotherapy,ctDNA in peripheral blood is characterized by convenient extraction and high specificity.Detection of ctDNA is not only conducive to find minimal residual disease and metastasis,but also help clinicians better evaluate the curative effect and judge prognosis after radiotherapy,which will provide a new way of thinking for the diagnosis and treatment strategy of tumor.
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The feature of gasoline Raman spectra which were used to study the quantitative analysis of the research octane number (RON) were extracted for the first time using backward interval partial least squares (BiPLS). In the experiment, the sample set partitioning based on joint x-y distances (SPXY) method was used to divide the training set, the cross validation set and the test set. And the robust regression algorithm was used to remove the abnormal sample. The partial least squares model was established using feature selected by the BiPLS algorithm. Compared with the model without feature selection, it was shown that the backward interval partial least squares algorithm could reduce the input dimension by 50.00%, and the root mean square error of cross validation(RMSECV) by 18.92% and the root mean square error of prediction (RMSEP) by 13. 86%. The backward interval partial least squares algorithm can effectively extract the feature from gasoline Raman spectrum,reduce the model complexity, and improve the prediction accuracy of the model,and has great application prospect in the quantitative analysis of research octane number.
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BACKGROUND:Insufficient oral soft tissues in the implant zone may have a negative effect on the wound healing and the aesthetic restoration in the late stage. Platelet-rich fibrin can promote the wound healing of soft tissue defects. But there is stil a lack of in-depth studies on the promotion of oral soft tissue defects in animal experiments. OBJECTIVE: To compare the repairing effects of platelet-rich fibrin and colagen membrane on soft tissue defects of the hard palate in New Zealand rabbits. METHODS:Fifty-four New Zealand rabbits were randomly divided into three groups (n=14 per group): platelet-rich fibrin group, colagen membrane group and blank control group. A 5 mm-diameter circular ful-thickness soft tissue defect was made in the front of the hard palate, 2 mm distant to the rear maxilary incisors and mucosal edge of the bilateral hard palates. Autologous platelet-rich fibrin membrane or colagen membrane were implanted into the defect in the platelet-rich fibrin group and colagen membrane group, respectively. No treatment was given in the blank control group. General observation of the wound and wound healing analysis were performed at days 3, 7, 14, 21, 28, 56 post operation. Hematoxylin-eosin staining, CD31 immunohistochemical staining and Masson staining were used to observe inflammatory reaction, angiogenesis and colagen formation in the surgical site. RESULTS AND CONCLUSION:The wound healing rate was fastest in the platelet-rich fibrin group, and no obvious scar formed. At 3 days post operation, there was no difference in the wound healing rates among the three groups; at 7 days, the wound healing rate in the platelet-rich fibrin group was significantly higher than that in the colagen membrane group and blank control group (P < 0.05). At 3 and 7 days after operation, the inflammatory reaction in the platelet-rich fibrin group was less than that in the colagen membrane and blank control groups (P < 0.05); at 14, 21, 28 and 56 days, there was no significant difference between the three groups. At 7, 14, 21 days after operation, the average absorbance value of CD31 in the platelet-rich fibrin group was significantly higher than that in the colagen membrane and blank control groups (P < 0.05). The average absorbance value of colagen formation in the platelet-rich fibrin group was significantly higher than that in the colagen membrane and blank control groups at 7 days after operation (P < 0.05), significantly higher than that in the blank control group at 14 days (P < 0.05), but lower than that in the colagen membrane and blank control groups at 21, 28 and 56 days after operation (P < 0.05). These findings show that platelet-rich fibrin can reduce inflammatory reactions in the process of wound healing, accelerate the angiogenesis, regulate the metabolism of colagen, reduce the formation of scar and improve the quality of wound healing, thereby promoting the repair of oral soft tissue defects.
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BACKGROUND:Hair fol icle stem cel s derived from skin and hair have the most readily available sources, and cannot lead to serious complications and immunogenicity after col ection, which can be used for autologous transplantation. OBJECTIVE:To provide effective experiment basis for hair fol icle stem cel s in the repair of skin wound through reviewing the role of hair fol icle stem cel s in promote the repair of skin wound. METHODS:Articles related to hair fol icle stem cel s for the repair of skin wound were retrieved in CNKI and PubMed databases (1999-01/2014-12). The key words were“hair fol icle stem cel , skin repairing, regenerative medicine, tissue engineering”in Chinese and English, respectively. A total of 45 articles based on inclusion criteria and exclusion criteria were obtained for the review. RESULTS AND CONCLUSION:Hair fol icle stem cel s belong to adult stem cel s, which are easy to access, have a significant number, and possess differentiation potential and safety. Hair fol icle stem cel s can promote the repair of skin wound and provides good seed cel s for regenerative medicine and tissue engineering research through early vascularization of the skin, epidermal and appendage regeneration, signaling pathways, and transcription factors.
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<p><b>OBJECTIVE</b>To explore the effect of electro-acupuncture to improve the bladder function after acute spinal cord injury in rats and its possible mechanism.</p><p><b>METHODS</b>Sixty healthy adult male SD rats of SPF grade, with body weight of 220 to 250 g, one week after feeding adaptation, were randomly divided into sham operation group, model group, electro-acupuncture group, electro-acupuncture control group with 15 rats in each group. Sham operation group underwent no stimulation, and the moderate damage model of spinal cord injury were made in other three groups according to modified Allens method. The model group were not treated, electro-acupuncture group were treated with electro-acupuncture on Zhibianxue and Shuidaoxue, and electro-acupuncture control group were treated with electro-acupuncture on 0.5 inch next to Zhibianxue and Shuidaoxue. The frequency of 2/100 Hz, current of 1 mA, stimulation time of 15 min, once a day, left and right alternately stimulate every time, for a total of 7 times. The changes of residual urine volume and urine output in rats at the 1st and the 7th days after operation were observed. And 7 d later, the rats were sacrificed and the injured spinal cord were taken out to observe the apoptosis, and to detect the changes of Bcl-2, Bax, Bad content.</p><p><b>RESULTS</b>After modeling,the rats of three groups showed different bladder dysfunction. In electro-acupuncture group and electro-acupuncture control group, the residual urine volume of the 7th day after operation was significant lower than the 1st day after operation (P < 0.001), and there was statistically significant difference on the 7th day after operation between two groups (P < 0.001). Compared with model group, the urine output of electro-acupuncture group and electro-acupuncture control group was significantly increased on the 7th day after operation, and there was sig- nificant difference between electro-acupuncture group and electro-acupuncture control group (P < 0.001). Electro-acupuncture can inhibit apoptosis of spinal cord neurons by TUNEL detection. Postoperative at 7 d, the rate of nerve cell apoptosis in electro -acupuncture group and electro-acupuncture control group was significant increased than model group (P < 0.01, P < 0.05), and there was significant difference between electro-acupuncture group and electro-acupuncture control group (P < 0.005). Compared with model group, the positive expression rate of Bax, Bad decreased (P < 0.01, P < 0.05), and Bcl-2 increased (P < 0.01) in electro-acupuncture group and electro-acupuncture control group,there was significant difference between electro-acupuncture group and electro-acupuncture control group (P < 0.01).</p><p><b>CONCLUSION</b>Electro-acupuncture can obviously promote the repair of acute spinal cord injury,its mechanism may be through increasing Bcl-2, inhibiting the expression of Bax, Bad, which inhibits the apoptosis of spinal cord neurons.</p>
Subject(s)
Animals , Male , Rats , Apoptosis , Electroacupuncture , Immunohistochemistry , In Situ Nick-End Labeling , Neurons , Cell Biology , Physiology , Rats, Sprague-Dawley , Spinal Cord Injuries , Pathology , Therapeutics , Urinary BladderABSTRACT
ObjectiveTo establish rat model of traumatic brain injury combined with hemorrhagic shock.Methods Rat models of traumatic brain injury (produced by free fall impact method) combined with hemorrhagic shock (produced by venous injury method) were established and the related physiological parameters were recorded.The neurological impairment score,cerebral edema degree and blood brain barrier (BBB) were determined by using neurofunction scales,dry-wet method and Evans blue (EB) respectively.HE staining and immunohistochemical staining were applied to evaluate the pathological changes in brain sections.ResultsBlood pressure dropped from 95 mm Hg to 25 mm Hg within three minutes after modeling and maintained around 60 mm Hg one hour later.Neurological impairment score was increased dramatically.The ratio of water content in the brain tissue was elevated nearly from 77％ to 81％.The concentration of EB residual in the brain tissue was increased more than one fold.Neuronal pathological abnormalities,including neuron shrinking,dark eosinophilic staining,perineuronal vacuole in HE staining,and positive staining of β-amyloid precursor protein (β-APP) in immunohistochemical staining were also observed. ConclusionsRat models of traumatic brain injury combined with hemorrhagic shock are successfully established.In addition,the main pathological changes,such as cerebral edema,disruption of BBB,neuron damage,and expression of β-APP are replicated.
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Objective Angiotensin Ⅱ (Ang Ⅱ ) contributes to modulating blood pressure by stimulation of Ang Ⅱ AT1 receptors. We devised a rat transient middle cerebral artery occlusion (MCAO) model to assess whether oxidative damage is decreased after pretreatment with Angiotensin Ⅱ AT1 receptor blocker (ARB). Methods After 2 weeks pretreatment with ARB 0. 5 and 1 mg/kg, the male Wister rats were subjected to 2 h middle cerebral artery occlusion (MCAO). At 24 h, the lumen diameter of middle cerebral artery, the plasma level of 8-hydroxy-2'-deoxyguanosine (8-OHdG), and HIF-1 a levels were recorded and compared. Results After pretrcatment with ARB 0.5 and 1 mg/kg, blood pressure did not significantly change compared with that of controls. In the group of candesartan at 1 mg/(kg· day), the lumen diameter was significantly increased compared to that in control group [(86.0±5.0) μm vs. (69.0± 2.1) μm; P<0. 01, n = 6- 8]. The plasma 8-OHdG levels of ARB pretreatment groups were decreased. In immunohistochemical findings, 8-OHdG- and HIF-1α-containing cells in ARB pretreatment groups were decreased. Conclusion Brain ischemia and oxidative damage can be reversed by AT1 receptor blockade in normotensive rats after transient cerebral artery occlusion.
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Objective To explore the role and significance of matrix metalloproteinase-9 (MMP-9) in angiogenesis through observing the relationship between the expression of MMP-9 and microvessel density (MVD) in glioma. Methods The expressions of MMP-9 and CD34 in 10 cases of normal brain tissues and 58 cases of glioma (14 cases of grade Ⅰ , 20 cases of grade Ⅱ , 15 cases of grade Ⅲ, and 9 cases of grade Ⅳ ) were detected by immunohistochemical streptavidin-peroxidase technique. The positive cells of MMP-9 and the positive microvessels were examined under binocular light microscope. Results The positive expression of MMP-9 in glioma was located in the tumor-cell cytoplast and endothelial cells. The positive rate of MMP-9 in glioma of grade Ⅰ, Ⅱ, Ⅲ and Ⅳ was 42.9%, 65.0%, 86.7% and 88. 9%, respectively. The expression of MMP-9 was obviously higher than that of normal brain tissues (P<0.01) and positively correlated with glioma malignancy (rz =0. 597, P<0.05). MVD was correlated with glioma malignancy (H=47. 865, P<0. 05). The expression of MMP-9 was significantly correlated with MVD (rz =0.897, P<0.01). Conclusion The expressions of MMP-9 and MVD are correlated with glioma malignancy, which may be helpful in judging the malignancy, invasion and prognosis. MMP-9 plays an important role in angiogenesis of glioma and accelerates glioma malignancy development by promoting angiogenesis.
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Objective To investigate the anti-tumor effect and mechanism of tamoxifen on rat C6 glioma cells. Methods C6 cells were cultured in Dulbecco's modified Eagle's medium (DMEM) with 3% fetal calf serum (FCS), and treated with tamoxifen of different concentrations, i.e. group A (1.25μmol/L), group B (2.50 μmol/L), group C (5.00 μmol/L), group D (10.00 μmol/L), group E (20.00 μmol/L) and control group (0.00 μmol/L). Morphological changes, MTT assay and 5-bromo-2'-deoxyuriding labeling ratio were assessed. Apoptosis was observed by flow cytometry. Results C6 cells treated with different doses of tamoxifen for 24, 48, and 72 hours became irregular in shape, while cells treated with vehicle grew normally. MTT assay showed that tamoxifen did not suppress C6 cell growth until 72 hours after treatment. Seventy-two hours after treatment, there were significant differences in cell viable rate between group A versus groups C, D and E; so did group B versus group D as well as group E (P<0.05). BrdU incorporation assay indicated significant difference of BrdU labbled index (BrdU LI) among groups A, C, E and control group 48 hours after treatment (P<0.05). And the BrdU LI decreased with the increased concentration of tamoxifen. Flow cytometry (FCM) showed significant difference between treated group and control group at 24, 48, and 72 hours after treatment (P<0.05). Conclusion Tamoxifen significantly suppresses the growth of C6 glioma cells in a time- and dose-dependent manner. The mechanism of tamoxifen suppressing C6 glioma cells may be inhibiting proliferation and inducing apoptosis. Therefore, tamoxifen can be a candidate as a chemotherapy agent for glioma.
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Objective Angiotensin Ⅱ (Ang-Ⅱ) increases NADPH oxidase activity and stimulates the production of reactive oxygen species (ROS) including superoxide anion through Ang Ⅱ AT1-receptor (AT1-R) activation. ROS is involved in various pathological processes in brain ischemia. We investigated whether the AT1-R blocker (ARB) candesartan can protect normotensive rats against brain ischemia. Methods After 2-week pretreatment with candesartan, rats were subjected to 2 hours middle cerebral artery occlusion-reperfusion (MCAO-R) and 24 hours later, the infarct volume, iNOS, and eNOS mRNA in the internal carotid artery was recorded and compared. Results Candesartan pretreatment reduced cerebral ischemia and oxidative brain damage after MCAO-R in normotensive rats, resulting in a decreased cortical infarct volume [0.5 mg/kg candesartan, (46.8±13.2)mm3; 1.0 mg/kg candesartan, (19.3±15.3)mm3 vs. control, (111.7±14.3)mm3; P<0.05, P<0.01, respectively]. Candesartan pretreatment increased the eNOS mRNA level in the internal carotid artery. Conclusion In normotensive rats exposed to MCAO-R, candesartan protectes against brain ischemia. This effect may represent a significant therapeutic advantage and may induce end-organ protection even at normal blood pressure.
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<p><b>OBJECTIVE</b>To discuss the early diagnostic methods and therapeutic principles of aneurysmal subarachnoid hemorrhage (SAH), and evaluate the therapeutic efficacy objectively.</p><p><b>METHODS</b>Using neuro-imaging examinations combined with case history and clinical symptoms to make the early diagnosis of 96 case with aneurysmal SAH, and Guglielmi detachable microcoil (GDC) was utilized for early intracapsular embolization in the ruptured aneurysms. Efficient symptomatic treatment was done early after operation.</p><p><b>RESULTS</b>All of 96 cases were early diagnosed and successfully embolized; Among them, the aneurysmal lumen was 100% occluded in 83 cases, 95% in 8 cases, 90% in 5 cases. There were 3 cases complicating with aneurysms rupture during operation, 5 cases with cerebral vasospasm. One case was affected by microcoil terminal escape after operation, 3 recurrent cases were all cured with secondary GDC embolization. There were 9 complications associated with embolization techniques and 13 cases (13.5%) occurring permanent sequelae associated with SAH. According to the Glasgow prognosis score, 77 patients got grade I, 7 grade II, 6 grade III, 3 grade IV, and 3 grade V. The mortality rate was 3.1%.</p><p><b>CONCLUSIONS</b>To make early etiological diagnosis of the SAH patients, using GDC to embolize the aneurysms, and earlier efficient symptomatic treatment are important methods to improve the curative rate and reduce the mortality rate.</p>