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@#<b>Objective</b> To correct the counting loss of <sup>37</sup>Ar below the activity threshold during the measurement of the absolute activity of the inert radioactive gas <sup>37</sup>Ar using the proportional counter filled with gas. <b>Methods</b> Monte Carlo simulation with Geant4 was performed to establish a proportional counter model and output the energy deposition spectrum of <sup>37</sup>Ar, which were used to simulate and analyze the causes and correction of counting loss. <b>Results</b> The photon detection efficiency was only 38.7% at 60 kPa. The counting loss was mainly caused by the wall effect produced by the photons, which could be reduced by increasing the gas pressure and corrected by extrapolation. The influence of wall effect at 100 kPa was 4.4%, and the deviation between simulation and experiment was < 0.6%. <b>Conclusion</b> A factor could be calculated by Geant4 simulation for the correction of counting loss, thus achieving the accurate measurement of <sup>37</sup>Ar activity by proportional counter.
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Objective To study the changes of inflammatory response and apoptosis in parotid gland tissues of rats after X-ray irradiation,and to explore the protective effect and possible mechanism of Sarcandra glabra on radiation-induced parotid injury in rats.Methods A total of 120 male rats were randomly divided into 5 groups (24 for each):control group,single irradiation group,radiation combined withahigh (26.8g· kg-1 · d-1),moderate (13.4g· kg-1 ·d-1) and low (6.7g· kg-1 · d-1) dosage of Sarcandra glabra group.The parotid gland of rats in the irradiation group received 15 Gy X-ray.Rats in each group were anesthetized with 2％ pentobarbital sodium (0.16 ml/100 g) at 10,40 and 70 d after irradiation and blood was collected from abdominal aorta.ROS levels in blood serum of each group were detected on the 10th,40th and 70th days after irradiation.After parotid gland tissue was taken,the pathological changes and ultrastructural changes were observed by hematoxylin-eosin (HE) staining and transmission electron microscopy,respectively.The expression level of TNF-α in parotid gland tissue was detected by immunohistochemistry,and apoptosis of parotid cells was detected by TUNEL assay.Results The content of ROS and the expression of TNF-α protein in the single irradiation group were simultaneously increased compared with the control group (t =-24.723,-35.013,-19.515,P＜ 0.05;t =-13.563,43.519,-15.249,P＜ 0.05),while they were reduced by Sarcandra glabra in a dosage dependent manner,especially in the high dosage group of Sarcandra glabra (t =5.295,8.138,6.545,P＜0.05;t =10.093,-7.868,10.539,P＜0.05).In the control group,the parotid gland tissue structure was intact,without congestion,exudation,edema,etc.For the single irradiation group,the parotid gland tissue became hyperemia,edema and inflammatory cell infiltration at 10 d after irradiation followed by fibrosis at 40 d after irradiation.These pathological alterations in the parotid gland tissue were significantly recovered when the rats were treated with Sarcandra glabra before irradiation,and the tissue damage was negatively correlated with drug dosage.TUNEL assay showed that the apoptosis rate of parotid gland cells in the single irradiation groups was higher than that in the control group (t=-4.639,-3.979,P＜0.05).Conclusions Sarcandra glabra protects parotid gland from radiation damage by scavenging radiation-induced ROS and declining inflammatory response,and thus it may be applied as a potential protective agent for radiation injury.
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Objective@#To study the changes of inflammatory response and apoptosis in parotid gland tissues of rats after X-ray irradiation, and to explore the protective effect and possible mechanism of Sarcandra glabra on radiation-induced parotid injury in rats.@*Methods@#A total of 120 male rats were randomly divided into 5 groups(24 for each): control group, single irradiation group, radiation combined with a high(26.8 g·kg-1·d-1), moderate(13.4 g·kg-1·d-1) and low(6.7 g·kg-1·d-1) dosage of Sarcandra glabra group. The parotid gland of rats in the irradiation group received 15 Gy X-ray. Rats in each group were anesthetized with 2% pentobarbital sodium (0.16 ml/100 g) at 10, 40 and 70 d after irradiation and blood was collected from abdominal aorta. ROS levels in blood serum of each group were detected on the 10th, 40th and 70th days after irradiation. After parotid gland tissue was taken, the pathological changes and ultrastructural changes were observed by hematoxylin-eosin (HE) staining and transmission electron microscopy, respectively. The expression level of TNF-α in parotid gland tissue was detected by immunohistochemistry, and apoptosis of parotid cells was detected by TUNEL assay.@*Results@#The content of ROS and the expression of TNF-α protein in the single irradiation group were simultaneously increased compared with the control group (t=-24.723, -35.013, -19.515, P<0.05; t=-13.563, 43.519, -15.249, P<0.05), while they were reduced by Sarcandra glabra in a dosage dependent manner, especially in the high dosage group of Sarcandra glabra (t=5.295, 8.138, 6.545, P<0.05; t=10.093, -7.868, 10.539, P<0.05). In the control group, the parotid gland tissue structure was intact, without congestion, exudation, edema, etc. For the single irradiation group, the parotid gland tissue became hyperemia, edema and inflammatory cell infiltration at 10 d after irradiation followed by fibrosis at 40 d after irradiation. These pathological alterations in the parotid gland tissue were significantly recovered when the rats were treated with Sarcandra glabra before irradiation, and the tissue damage was negatively correlated with drug dosage. TUNEL assay showed that the apoptosis rate of parotid gland cells in the single irradiation groups was higher than that in the control group (t=-4.639, -3.979, P<0.05).@*Conclusions@#Sarcandra glabra protects parotid gland from radiation damage by scavenging radiation-induced ROS and declining inflammatory response, and thus it may be applied as a potential protective agent for radiation injury.
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Objective To evaluate the effects of nitrous oxide inhalation on conscious sedation of patients during colonoscopy and analyze its risk factors. Methods From October 2016 to July 2017, a total of 154 patients undergoing colonoscopy were included in the study. The comfort level was rated using Modified Gloucester Comfort Scale ( MGCS). Factors affecting comfort level were analyzed by univariate analysis and multivariate Logistic regression, and then a comfort stratification predicting model was created. Results All 154 patients finished colonoscopy. The mean time of ideal anesthesia state was 195. 15 s. Among the 154 cases, 115 ( 74. 7%) were identified as comfort ( grade of MGCS from 1 to 3) and 39 (25. 3%) were rated as discomfort ( grade of MGCS from 4 to 5). Multivariate regression indicated that age ≥60 years ( P＝0. 000, OR＝1. 074, 95%CI: 1. 036-1. 114) and mild anxiety ( P＝0. 018, OR＝3. 338, 95%CI: 1. 227-9. 079) were associated with comfort level during colonoscopy.The established model with the age (X1) and mild anxiety (X2) was P＝eY/(1+eY), Y＝－3. 812+0. 071X1+1. 205X2(no anxiety was assigned 1, mild anxiety was assigned 2), and the area under the receiver operating characteristics curve was 0. 746 (95%CI: 0. 661-0. 830), which showed moderate predictive power of the final model. The model reached the highest predictive accuracy when the Yoden Index was 0. 838 with sensitivity of 50. 4% and specificity of 89. 7% for predicting comfort level of patients in conscious sedation status induced by nitrous oxide inhalation during colonoscopy. Conclusion Nitrous oxide can ease pain during colonoscopy, especially for patients over 60 years old and with anxiety. We can use it as an option according to actual circumstance in practice.
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Objective To evaluate the prognostic value of iASPP for nasopharyngeal carcinoma (NPC).Methods One hundred and thirty patients with nasopharyngeal carcinoma were initially diagnosed and treated between January and December 2012 in Department of Radiation Oncology of the First Affiliated Hospital of Guangxi Medical University.The clinical staging was classified according to the cancer staging criteria 2009 AJCC/UICC.All patients were treated by IMRT.Cisplatin-based concurrent chemotherapy was given to patients with stages Ⅲ-ⅣB disease.Immunohistochemistry was used to detect the expression of iASPP in the carcinoma tissues,and the clinicopathological features were compared among the patients with different expressions of iASPP.Furthermore,the relationship between the expression of iASPP and the efficacy in patients was explored.Results Of 130 patients,positive expression of iASPP was observed in 86 patients (66.2％),and negative expression in 44 patients (33.8％).There was significant difference in the positive expression rate of iASPP among the patients with different N-stage and clinical stages(x2 =7.565,4.947,P ＜ 0.01).At three months after treatment,no significant difference was found in the response rate of tumor with different expression of iASPP.In univariate analysis,the expression of iASPP was significant predictor of 3 year-DMFS (x2 =4.335,P =0.037) and PFS (x2 =6.640,P =0.01).Furthermore,N-stage was significant predictor of 3y-DMFS (x2 =8.058,P =0.005),PFS (x2 =9.554,P =0.002) and OS (x2 =6.987,P =0.008),respectively.By using multivariate Cox analysis,the expression of iASPP and N-stage was independent prognostic factors for PFS (x2 =4.336,5.228,P ＜ 0.05),respectively.Conclusions Positive expression of iASPP may be a poor prognostic factor for NPC patients.
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Objective To propose a new N staging system for nasopharyngeal carcinoma based on intensity-modulated radiotherapy (IMRT) and Radiation Therapy Oncology Group (RTOG) guidelines for cervical lymph node levels.Methods A retrospective analysis was performed in 324 patients with newly diagnosed nasopharyngeal carcinoma who had no distant metastasis confirmed by pathology and received IMRT in the Department of Radiation Oncology in The First Affiliated Hospital of Guangxi Medical University from January 2010 to December 2011.They were restaged according to the 7thedition of UICC/AJCC staging system for nasopharyngeal carcinoma.The survival rates were estimated using the Kaplan-Meier method and the log-rank test was used for univariate prognostic analysis.The Cox proportional hazards model was used for multivariate prognostic analysis.Results Of 324 patients,269(83.0%) had lymph node metastasis.The median follow-up was 58 months (6-77 months).The 5-year overall survival,disease-free survival,relapse-free survival,and distant metastasis-free survival rates were 84.8%,77.1%,92.7%,and 80.5%,respectively.Univariate and multivariate analyses of patients with positive cervical lymph nodes revealed that retropharyngeal lymph node status,cervical lymph node level,and laterality were evaluated as independent prognostic factors for nasopharyngeal carcinoma.According to the hazard ratio calculated,the N staging system was revised as follows:N0:no regional lymph node metastasis;N1:VⅡ a or/and unilateral levels (I,Ⅱ,Ⅲ,Va) involvement;N2:bilateral levels (I,Ⅱ,Ⅲ,Va) involvement;N3:levels IVa,Vb,and IVb+Vc involvement.Conclusions The proposed N staging system is based on IMRT and RTOG guidelines for lymph node levels and more practical,and can provide highly objective prediction of outcome and guide treatment in nasopharyngeal carcinoma.
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Objective To explore the relationship between positive cervical lymph nodes and distant metastasis after intensity-modulated radiotherapy(IMRT)in patients with nasopharyngeal carcinoma(NPC). Methods A retrospective analysis was performed on the clinical data of 474 patients who were newly diagnosed with NPC but no distant metastasis and received IMRT from 2010 to 2012. The survival rates were calculated by the Kaplan-Meier method. The log-rank test was used for comparison of survival rates and univariate prognostic analysis. The multivariate analysis was made by the Cox regression model. Results In the 474 patients, 400 had positive cervical lymph nodes and 122 had residual masses in the neck after IMRT. The four-year distant metastasis, overall survival, disease-free survival, local relapse-free survival, and distant metastasis-free survival(DMFS)rates were 13.71%(65/474), 82.9%, 81.4%, 93.5%, and 86.3%, respectively. The univariate and multivariate analyses showed that treatment approach, lymph node metastases in lower neck Ⅳ/Ⅴb/Ⅴcregions, the greatest diameter of the positive cervical lymph nodes, the diameter of residual lymph nodes, and time to lymph node recession were independent prognostic factors for DMFS(all P<0.05). Conclusions Chemoradiotherapy can reduce the distant metastasis rate after IMRT for NPC. The larger the cervical lymph nodes are,the more likely there are residual masses;the larger the residual cervical lymph nodes are, the higher risk of distant metastasis there is. Large cervical lymph nodes(≥6 cm),residual masses larger than 1 cm,and residual masses at 3 months after IMRT are negative prognostic factors for DMFS after IMRT for NPC. Better intervention treatment approaches need to be explored.
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Objective To investigate the tolerated dose of the optic nerves and chiasm in patients with locally advanced nasopharyngeal carcinoma(NPC)treated with intensity-modulated radiotherapy (IMRT). Methods A retrospective analysis was performed on dose characteristics and the incidence of radiation optic neuropathy in 108 patients with locally advanced NPC treated with IMRT at D 2>55 Gy in the optic nerves and chiasm in our hospital between May 2009 and December 2013. The Common Terminology Criteria for Adverse Events(CTCAE)Version 3.0 grading criteria were used for evaluating adverse reactions of the optic nerves and optic chiasm.A logistic regression analysis was performed to assess the risk factors for the development of radiation-induced optic neuropathy(RION). Results No patient had severe RION (grade 3-5),although 7 of the 108 patients had mild optic nerve disorder(grade 1-2). No patient-or treatment-related factors were found to be associated with the development of RION(P>0.05). With a median follow-up of 46 months(range,13-91 months),the 3-year estimated overall survival,local recurrence-free survival,and distant metastasis-free survival rates were 90.0%,94.5%,and 86.4%, respectively. Conclusions The dose constraint of<55 Gy derived for optic nerves and chiasm from conventional radiotherapy does not seem to apply to IMRT. For advanced NPC patients treated with IMRT, the dose constraints of optic nerves and chiasm might be relaxed in order to improve target coverage.
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Objective To establish a new T staging system for nasopharyngeal carcinoma ( NPC) based on magnetic resonances imaging ( MRI) and intensity?modulated radiotherapy ( IMRT) . Methods A retrospective analysis was performed on the clinical data of 608 patients who were newly diagnosed with non?metastatic NPC by MRI and treated with IMRT in our hospital from 2008 to 2010. All patients were staged according to the 7th edition of the UICC/AJCC staging system for NPC. The survival rates were calculated using the Kaplan?Meier method and analyzed using the log?rank test. The Cox regression model was used for multivariate analyses. To deal with the deficiency in the current UICC/AJCC staging system, a new T staging system for NPC was established and systematically evaluated. Results The 5?year follow?up rate was 94?5%. The 5?year overall survival (OS), disease?free survival, local relapse?free survival (LRFS), and distant metastasis?free survival rates were 81?5%, 80?1%, 86?0%, and 81?1%, respectively. The univariate and multivariate analyses showed that the anatomic structures of nasopharynx, parapharyngeal space, and skull base were influencing factors for the OS rate (P=0?000?0?045). New T staging criteria were proposed based on the risk differences and survival curves:stage T1:invasion of the nasopharynx, parapharyngeal space, oropharynx, nasal cavity, skull base, and internal pterygoid muscle;stage T2:invasion of the external pterygoid muscle, paranasal sinus, intracalvarium, infratemporal fossa, and cranial nerves. The proposed T staging system achieved a good separation in both OS and LRFS curves. Conclusions The proposed new T staging system gives an objective prognostic prediction in patients with NPC, which provides an exploratory attempt toward a new clinical staging system for NPC.
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Objective To study the effect of Sarcandra Glabra on the expression of signal transduction molecules of TGF-β1/Smads signaling pathway in miniature pig of radiation-induced lung injury.Methods 75 miniature pigs were divided into control group,radiation group and radiation plus medication group randomly.At 1 week before exposure of right lung with 15 Gy γ-rays,the miniature pigs in radiation plus medication group were given Sarcandra glabra,while those in the other groups received an equal amount of saline.Right lung were taken at weeks 2,4,8,12 and 24 after irradiation,the pathological changes in the lung tissue were observed by HE staining,and the expression of mRNA and protein of TGF-β1,Smad2,Smad3,and Smad7 were detected by real-time PCR and western blotting,respectively.Results Sarcandra glabra reduced the inflammation and fibrosis of the lung tissue in miniature pig after irradiation.Compared with control group,the expressions of TGF-β1 and Smad3 were significantly increased at 2 weeks after irradiation(P ＜ 0.05),Smad2 and Smad7 were increased at 8 and 12 weeks after irradiation(P ＜ 0.05),respectively,in the radiation group.Compared with the radiation group,the expressions of TGF-β1 and Smad2 were significantly decreased(P ＜ 0.05) from the fourth and eighth week,respectively,Smad3 had no obvious change while Smad7 was significantly increased from the second week in the radiation plus medication group (P ＜ 0.05).Conclusions Sarcandra Glabra plays protective effect on radiation-induced lung injury in miniature pig by regulating TGF-β1,Smad2 and Smad7 expressions in the TGF-β1/Smads signaling pathway.