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Objective @#To evaluate the implementation, application, and problems and suggestions of the Radiation Shield- ing Requirements in Room of Radiotherapy Installations—Part 1: General Principle (GBZ/T 201.1—2007) through a survey of relevant personnel in radiation health technical service institutions, and to provide a scientific basis for further revision and implementation of this standard.@*Methods@#A questionnaire survey was conducted among randomly selected per- sonnel in radiation health technical services across China, which mainly investigated the awareness, training, application, and revision suggestions related to the GBZ/T 201.1—2007. The results were aggregated and analyzed.@*Results@#A total of 184 evaluation questionnaires on the GBZ/T 201.1—2007 were collected from technical service staff in 25 provinces. Among the responders, 64.1% thought that the standard had been widely applied; 91.8% thought that the standard could meet work needs; only 54.3% ever received relevant training on the standard; 68.5% used the standard once or more per year; 33.7% thought that the standard needed to be revised.@*Conclusion@#The personnel in radiation health technical services have a high awareness rate of the GBZ/T 201.1—2007 and its contents, but their familiarity with and application of the standard need to be improved. Relevant departments should strengthen the training and promotion of the standard, and part of the standard should be revised.
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Objective@#To study a method for verifying the doses to PTV and OAR as well as the 2D dose distribution arising from IMRT through using radiochromic films and TLDs.@*Methods@#Totally 7 medical electronic linear accelerators from Varian, Siemens and Elekta were selected. The polystyrene phantom provided by IAEA was conducted with CT scan. After irradiation with 6 MV X-rays, the TLDs and films were returned to the secondary standard dosimetry laboratory of China CDC for measurement and estimation.@*Results@#According to the IAEA requirements, the relative deviations between TLD-measured and TPS-planned values for PTV and OAR doses were both within ±7.0%. For PTV, the measured relative deviations for 5 accelerators were in the range of -4.0% to 3.4%, consistent with the IAEA requirements, whereas the values for the other 2 accelerators were in the range of -7.0% to 10.6%, not consistent with the requirements. For OAR, the values for 4 accelerators were in the range of -5.6% to 3.3%, consistent with the IAEA requirements, whereas the values for the other 3 accelerators were in the range of -20.8% to 11.5%, not meeting the requirements. As required by the IAEA, the 2D dose distribution 3 mm/3% pass rate should be higher than 90%. The measured values for 5 accelerators were in the range of 91.8% to 98.5%, consistent with the requirements, whereas the values measured for the other 2 were 45.0% and 77.0% respectively, not meeting the requirements.@*Conclusions@#It is feasible for using TLDs and radiochromic films to verify the doses to PTV and OAR and the 2D dose distribution in IMRT. This method should be applied to not only quality verification but also hospital internal audit to the extent possible.
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Objective To study a method for verifying the doses to PTV and OAR as well as the 2D dose distribution arising from IMRT through using radiochromic films and TLDs.Methods Totally 7 medical electronic linear accelerators from Varian,Siemens and Elekta were selected.The polystyrene phantom provided by IAEA was conducted with CT scan.After irradiation with 6 MV X-rays,the TLDs and films were returned to the secondary standard dosimetry laboratory of China CDC for measurement and estimation.Results According to the IAEA requirements,the relative deviations between TLD-measured and TPS-planned values for PTV and OAR doses were both within ±7.0％.For PTV,the measured relative deviations for 5 accelerators were in the range of-4.0％ to 3.4％,consistent with the IAEA requirements,whereas the values for the other 2 accelerators were in the range of-7.0％ to 10.6％,not consistent with the requirements.For OAR,the values for 4 accelerators were in the range of-5.6％ to 3.3％,consistent with the IAEA requirements,whereas the values for the other 3 accelerators were in the range of-20.8％ to 11.5％,not meeting the requirements.As required by the IAEA,the 2D dose distribution 3 mm/3％ pass rate should be higher than 90％.The measured values for 5 accelerators were in the range of 91.8％ to 98.5％,consistent with the requirements,whereas the values measured for the other 2 were 45.0％ and 77.0％ respectively,not meeting the requirements.Conclusions It is feasible for using TLDs and radiochromic films to verify the doses to PTV and OAR and the 2D dose distribution in IMRT.This method should be applied to not only quality verification but also hospital internal audit to the extent possible.
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Objective To verify the accuracy of multi-leave collimators (MLC) leaves position in intensity modulated radiation therapy (IMRT) using radiochromic films.Methods 7 medical electronic linear accelerators of Varian,Elekta or Siemens design were chosen.25 cm× 25 cm films were put on 30 cm×30 cm×3.0 cm homogeneous solid phantom and covered with a 2.0 cm thick of homogeneous solid phantom.The CT scanned images were transmitted to TPS for plan preparation.A 5 strip picket fence pattern was formed by MLC leaf,each 3 cm long and 0.6 cm wide,with 3.0 cm wide strip separation.At the maximum dose point,the SSD was 100 cm,with 250 MU per strip.After exposure,the films were transmitted to the dosimetry laboratory at IAEA for measurement and calculation.Results For 6 of 7 accelerators chosen,the differences of film-measured and TPS-planned MLC leaf position for every fence were within ± 0.5 mm as required by IAEA,and the other one not consistent with the requirements.The difference of film-measured MLC leaf position between each pair and all pair for 7 accelerators were within ± 0.5 mm,in line with IAEA's requirements.The differences of film-measured MLC leaf actual width were within 0.75 mm,as required by IAEA,for 6 accelerators and-0.8 mm for the other one,not consistent with the IAEA requirements.The standard deviations of film-measured MLC leaf actual width for all pairs for 6 accelerators were ＜0.3 mm,in line with IAEA requirements,but 0.4 mm for the other one,not consistent with IAEA requirements.Conclusions It is simple,fast and accurate to use radiochromic films for verification of the accuracy of MLC leaf position in IMRT.Therefore it is advisable to widely use radiochromic films in IMRT clinical practice.
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Objective To measure absorbed dose and verify two-dimensional dose distribution from IMRT MLC using thermoluminescence dosimeters (TLDs) and films.Methods The teflon phantom was scanned by CT and its images were transmitted to TPS for planning.The 6 Gy-corresponding MUs were calculated at 90 cm SSD and 10 cm depth and on 5 cm × 5 cm radiation field.All the plans were implemented at 7 medical linear accelerators,which were produced by Varian,Elekta and Siemens and selected from 7 third-grade first-class hospitals according to the technical conditions of various regions in Sichuan province.The homogeneous solid phantoms used in hospitals were covered by 30 cm × 30 cm and 25 cm × 25 cm films.Then,the films were covered by thicker-than-20 cm phantoms.Finally,the plans were implemented by aligning the center of beams to the films center.Results The relative deviations of the measured absorbed dose to TPS-planned dose were 1.4％,3.7％,-2.5％,-0.3％,4.9％,4.9％,5.0％ for TLDs and 4.7％,4.3％,1.5％,3.9％,-1.6％,3.3％,-1.3％ for films,respectively,all consistent with the limit of less than 5％.The passing rates of 2D dose distribution (3 mm/3％) were 99.9％,98.5％,98.5％,97.9％ and 70.0％ for 5 accelerators,with only one not consistent with the requirements.Conclusions It is convenient to measure the absorbed dose to photon beam field and verify two-dimensional dose distribution using TLDs and films,which can provide quality assurance for radiation treatment plans.
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<p><b>OBJECTIVE</b>To screen differentially expressed genes in hyperplastic scar to explore the pathogenesis of hyperplastic scar and identify new therapeutic targets.</p><p><b>METHODS</b>Three pairs of surgical specimens of hyperplastic scar and adjacent normal skin tissues were collected to investigate the differentially expressed genes in hyperplastic scar using Agilent gene oligonucletide microarray and clustering analysis. DAVID Bioinformatics Resources 6.7 was used for GO analysis and pathway analysis.</p><p><b>RESULTS AND CONCLUSION</b>Distinctly different gene expression profiles were found between hyperplastic scar tissues and normal skin tissues. Compared with normal skin tissue, hyperplastic scar tissues showed 3142 up-regulated and 2984 down-regulated genes by two folds and 28 up-regulated and 44 down-regulated genes by 5 folds after repeating the experiment once; after repeating the experiment twice, 3004 genes were found up-regulated and 3038 down-regulated by 2 folds and 25 up-regulated and 38 down-regulated by 5 folds in hyperplastic scars. In all the 3 specimens, 1920 genes were up-regulated and 1912 down-regulated by 2 folds and 18 up-regulated and 29 down-regulated by 5 folds. The dysregulated genes in hyperplastic scar were involved in cell cycles, cell proliferation, immune response and cell adhesion (CDKN1C, CDKN2A, CTNNA3, COL6A3, and HOXB4) and in signaling pathway of focal adhesion, TGF-beta signaling pathway, p53 signaling pathway, cell cycle, and tumor-associated pathways (TGFβ1, CDKN1C, CDKN2A, CDC14A , ITGB6, and EGF).</p>
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Humans , Cicatrix , Genetics , Cluster Analysis , Computational Biology , Down-Regulation , Gene Expression Profiling , Oligonucleotide Array Sequence Analysis , Signal Transduction , Transcriptome , Up-RegulationABSTRACT
BACKGROUND: Transplantation of microencapsulated rabbit Schwann cells in the rat spinal cord can relieve inflammatory reaction, promote spinal cord regeneration, but the precise mechanisms remain unclear. OBJECTIVE:To observe basic fibroblast growth factor (bFGF)expression and movements recovery following transplantation of microencapsulated rabbit Schwann cells in rat spinal cord. METHODS: The sciatic nerves taken out from rabbits wore digested with mixed enzyme and were made into Schwann cells suspension. Then we used air-jet method to make Schwann cells microcapsule. Using the same method, empty microcapsule was made. Sprague Dawiey rats were randomly divided into cell group, empty microcapsule group and microcapsule group. Conducted by hemisection injury of spinal cord,the rats in cell group,empty microcapsule group and microcapsule group were implanted with gelatin sponge with 10μL Schwann cells suspension, gelatin sponge with 10 μL empty microcapsule and 10 μL microencapsulated Schwann cells. Normal group was left intact. After operation, we observed hindlimb movements recovery in rats with the Basso, Beattie, and Bresnahan (BBB) scale. Meanwhile,a set of sections were stained immunohistochemically for bFGF expression, another set of sections wore stained for hematoxylin-eosin and Nissal. RESULTS AND CONCLUSION: After spinal cord injury, rat right hindlimb affected paralysis immediately. At 7, 14 and 28 daysfollowing transplantation,motor function in rat hindlimb was significantly recovered, and the BBB scores were significantly higher in microencapsulated schwenn cells than in cell and empty microcapsule group (P < 0.05 or P < 0.01). bFGF positive products were mainly distributed in cytoplasm of the spinal neuron and nucleus of neuroglical cell. The numbers of bFGF positive glial cells mainly appeared surrounding the spinal cord injured site on days 1, 3, 7 and rose to its peak on day 3 and began to appear in neuronal calls on day 14. The number of bFGF positiv cells in microcapsule group was significantly superior to that in cell group and empty microcapsule group. From then on, the bFGF expreSsion was significantly decreased in each group. These indicated that transplantation of microencapsulated Schwann cells can inhibit the immunological rejection after xenotransplantation, suppress inflammatory reaction, improve the expression of bFGF, increase hindlimb movements recovery and spinal cord regeneration after spinal cord injury.
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OBJECTIVE:To investigate the influences of Schwann cells-alginic acid sodium hydrogel transplantation on cellular apoptosis,Bcl-2 expression,and lower limb locomotor function in a rat model of spinal cord injury.METHODS:SD rats of clean grade were randomly divided into 4 groups:normal control,simple injury,Schwann cells,and Schwann cells-alginic acid sodium hydrogel.Spinal cord transaction model was established in the latter 3 groups.Gelatin sponge blocks containing Schwann cells suspension were transplanted into the Schwann cells group.Schwann cells-alginic acid sodium hydrogel was transplanted into Schwann cells-alginic acid sodium hydrogel group.No treatments were performed in the normal control and simple injury groups.At 12 hours,1,3,7,and 21 days after surgery,animals were assessed using Basso,Beattie and Bresnahan (BBB) locomotor rating scale and were sacrificed.The spinal cord-transected segments were taken to prepare paraffin sections for TUNEL and Bcl-2 staining to quantitate apoptotic cells and Bcl-2 cells in the injured spinal cord and to investigate their distributions.RESULTS:A small number of slightly stained Bcl-2 positive cells were observed in the normal control group.In the simple injury group,Bcl-2 immunoreactive cells peaked at 3 days after surgery,and the expression level was close to normal level at 14 days.Following Schwann cells-alginic acid sodium hydrogel transplantation,Bcl-2 immunoreactive cells in the spinal cord-transected segments were significantly increased till 7 days (P＜0.05) and remained this level for more than 14 days.In the simple injury group,apoptotic cells were most as compared with the remaining 3 groups,and peaked at 1 and 7 days following spinal cord injury,and they were mostly distributed in the white matter.BBB scores were significantly higher in the Schwann cells-alginic acid sodium hydrogel transplantation group than in the simple injury and Schwann cells groups (P＜0.05).CONCLUSION:Schwann cells-alginic acid sodium hydrogel transplantation could inhibit cellular apoptosis and enhance Bcl-2 expression in the spinal cord-transected segments,and thereby promote the recovery of locomotor function after spinal cord injury but did not reach normal levels.
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BACKGROUND: Schwann cells play an important role in axonal growth and myelin sheath formation of the peripheral nerve. Whether Schwann cells play the same role in the spinal cord had attracted considerable attention. Microencapsulation technology as an effective immune isolation technique can effectively keep Schwann cell activity to play the repair effect of Schwann cell in the spinal cord.OBJECTIVE: To observe the changes of myelin sheath in the injured transection of rats after transplantation of the alginic acid microencapsulated Schwann cells.DESIGN, TIME AND SETTING: The randomized controlled animal experiment was performed at the Basic Medical School of Nanchang University from March 2005 to February 2008.MATERIALS: Sciatic nerve trunk was obtained from adult rabbits to harvest Schwann cells in vitro using repeatedly differential velocity adherent technique, and to prepare Schwann cell suspension and microencapsulated Schwann cell suspension.METHODS: A total of 146 adult Sprague Dawley rats were used to establish models of right hemi-transection damage at T_(10) level and randomly assigned to four groups: simple injury group (n=44), cell transplantation group (n=44), microencapsulated cell transplantation group (n=44) and normal control group (n=14). At 1, 3, 7,14 and 28 days following surgery, 8 rats were selected from each group at each time point (2 from the normal control group) for perfusion and fixation. Spinal cord tissue was collected to make paraffin section, and then subjected to hematoxylin-eosin staining and Loyez myelin staining. In addition, 2 rats were selected from each group at 2 and 8 weeks. The spinal cord tissue was fixed, embedded in Epon816, stained using uranyl acetate and aluminum citrate, and then observed using an electron microscope.MAIN OUTCOME MEASURES: Neuron number and survival were observed surrounding the damaged region. Structural changes in the myelin sheath from spinal cord white substance at the damage site were measured.RESULTS: At 1 and 3 days following spinal cord injury, spinal neurons were degenerated and necrotic at damaged site, with reduced number of myelin sheath, loose structure, but above-mentioned was rare in the cell transplantation and microencapsulated cell transplantation groups. At 7 days, the reduced number of myelin sheath, with damaged structure was seen. The microencapsulated cell transplantation group was light. At 14 days, number of neurons was increased, with increased cell body, especially in the microencapsulated cell transplantation group. At 28 days, neurons gradually recovered, myelin sheath was gradually complete, with increased number in the microencapsulated cell transplantation group. There were significant differences compared with the simple injury and cell transplantation groups (P < 0.01). At 8 weeks, abundant myelin sheath was repaired, with new myelin sheath in the microencapsulated cell transplantation group.CONCLUSION: Microcapsule has immune isolation effects. Microencapsulated rabbit Schwann cells can promote the repair of rat spinal cord neurons and axonal myelinization.
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Objective To explore body image(BI),prosthesis satisfaction and quality of life(QOL)of amputees from Wenchuan earthquake and the relationship among them to provide evidence for the intervention.Methods A total of 21 amputees accepted a survey regarding QOL,BI,and satisfaction with prosthesis.The scale of SF-36 was used to assess QOL.Amputees Bodily Image Scale(ABIS)was;used to assess BI.A self-design questionnaire wag used to evaluate the prosthesis satisfaction of amputees.Results The scores of SF-36,ABIS,and prosthesis satisfaction wag 41.90 ±15.00,64.58 ±10.60,and 59.52±11.06,respectively.The ABIS scores in women(65.07 ±12.10)were hisher than that in men(63.20 ±5.0)(P＜0.05).There was a positive correlation between score of QOL and prosthesis satisfaction,but a negative correlation between QOL and BI.The negative correlations were also observed between BI and Vitality,BI and mental health.Prosthesis satisfaction had positive correla tions with education level.QOL and mental health.Conclusion The body image disturbance(BID)and dissatis faction with prosthesis may cause negative influences on the amputees'quality of life.Relevant intervention should be provided of amputees handling their prostheses and body images correctly and raising QOL.
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OBJECTIVE: To summarize the effects of glial cell line-derived neurotrophic factor (GDNF) on ischemia damage to nerve tissue and discuss the possibility of GDNF in repair of spinal cord injury based on the development of microencapsulation technology.DATA SOURCES: A search of Medline from January 1996 to October 2000 was performed for the English articles related to GDNF, ischemia damage to nerve tissue, spinal cord injury and microencapsulation technology by using the key words "glial cell line-derived neurotrophic factor, ischemia damage to nerve tissue, spinal cord injury". Meanwhile, we retrieved Wangfang database for search of the related articles in Chinese by using the same keywords in Chinese.STUDY SELECTION: Articles including intervention group and control group were selected after first review, and those which were significantly non-randomized researches were excluded. Then, the full-texts of the enrolled articles were retrieved. Inclusion criteria: ①randomized controlled study; ②the experiment/clinical research including horizontal control group. Exclusion criteria: duplicated researches.DATA EXTRACTION: Totally 300 articles were selected but only 15 were in coincidence with conclusion criteria. 285 articles were excluded, 264 of them were duplicated and non-randomized researches, and 21 were review articles.DATA SYNTHESIS: GDNF can provide nutrition to dopamine nerve cell in rat's middle brain, so as to decrease dopamine nerve cell's death. Also GDNF can protect dopamine nerve cell in cerebral infarction rats from ischemic injury, inhibit the produce of nitrogen monoxide and reperfusion injury after ischemia. GDNF is an effective protective factor against ischemia damage. Microencapsulation technology has a bright future in treating endocrinopathic neural diseases, and GDNF can play a great role in the development of microencapsulation technology.CONCLUSION: GDNF is a protective factor against ischemia damage to nerve tissue, which can be enhanced by microencapsulation technology.There is a bright future for the research on GDNF in the clinical repair of spinal cord injury.
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Objective To observe the changes of behaviour, NOS neurons, Nissl bodies and ultrastructure after L-NNA treatment of acute spinal cord injury in rats. Methods Using movement and incline plane(IP)score to observe hindlimbs movement of rats with spinal cord injury; NADPHd histochemistry, Nissl methed and electron microscopy were used for observation of changes of neuronal NOS, Nissl bodies and ultrastructure of three groups(normal control group, saline solution(NS)control group and L-NNA group). Re- sults 1. Changes of behaviour: Hindlimbs movement and IP score in L-NNA group is more potent than that in NS group(P
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Objective To explore the endothelial changes of renal artery of hypertension. diabetes and hypertension in-corpora- tion diabetes rat. Methods The scanning electron microscopy was used in experiment. Results The endothelium of renal artery of normal group were smooth and distinct. The surface of the endothelium were showed irregular and finger prints and red blood cells and mono- cytes adhered to endothelium in hypertensive group.All these changes were more prominent in hypertension incorporation diabetes group, so that the mononuclear cells were migrated into endothelium. Conclusion The endothelium of renal artery of hypertension, diabetes and hypertension incorporation diabetes rats showed abnonmal changes.
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The effect of concanavalin A (Con A) on nerve regeneration in heterograft was done in the present study. A segment about 5mm long was removed from the right sciatic nerve of adult rats. A 8mm of the heterograft nerve segment from the tibial nerve of the rabbit and pretreated by Con A was transplanted into the gap of the severed rat nerve. Regenerating nerve fibers were found from the proximal part of the sciatic nerve into the graft, and also from the graft into the distal part of the sciatic nerve at the 4th,8th and 12th week after transplantation. Regenerating nerve fibers existed separately or clustered into fascicles in the graft,as well as in the distal part of sciatic nerve. Some unmyeli-nated nerve fibers were scattered among the regenerating myelinated fibers. The gastrocnemius muscle was AChE-positive at 8th and 12th week after transplantation. In silver-combined AChE staining section, the regenerating nerve fibers could be seen connecting with the motor endplates. There were regenerating free nerve endings and nerve fascicles in the dermis and epidermis at 8th and 12th week after transplantation. The present study showed that the pretreatment of Con A had benefit to that the regenerating nerve fibers to pass through the heterograft and reinnervated to the targetes.ADepartment of Anatomy,Jiangxi Medical College,Nanchang 330006,China