Objective To compare the safety and feasibility of thoracoscopic extrapleural Nuss procedure with traditional intrapleural Nuss procedure. Methods Total 252 patients with pectus excavatum received Nuss surgery from July 2008 to June 2009 in Beijing children' s hospital. Patients had following condition were excluded; (1) recurrent pectus excavatum; (2) complicated with other diseases, and need simultaneous surgery; (3) older than 13-year-old; (4) extensive depression, and need two Nuss bar; or (5) extreme severe or severe unsymmetric. 131 cases were selected in our study and they were randomly divided into two groups, thoracoscopic extrapleural Nuss procedure ( n = 62 ) and traditional intrapleural Nuss procedure ( n =69). Perioperative information, postoperative complications, effectiveness and the location of the Nuss bar were compared between two groups. Results All the 131 patients had completed the procedure successfully. There were no significant differences in age, Haller index; surgical effects, operation time, blood loss, and hospital stay, between two groups. Postoperative complications between the two groups are not significant. 131 patients were followed up from 14 to 26 months, and no recurrence and long-term complications occurred. About more than half cases of extrapleural Nuss procedure group were break the pleural into thoracic cavity. Conclusion Both extrapleural and intrapleural Nuss procedure are safe and effective for pectus excavatum, but extrapleural Nuss procedure have no advantage to the intrapleural Nuss procedure, also it' s hard to observe the other side of thoracic cavity during the surgery, and not easy to grasp and to promote.

Objective To study the difference of image quality which based on different reconstruction in head dual‐energy computed tomography angiography (DECTA) scanning ,and evaluate the radiation dose which using different tube voltage in DEC‐TA .Methods An anthropomorphic head phantom with simulated arteries was used for DECTA scanning by different scan parame‐ters (tube voltage 80/140 kV and tube voltage 100/140 kV) ,the data was reconstructed with filtered back projection (FBP) and Si‐nogram Affirmed Iterative Reconstruction (SAFIRE) .The CT values with SD were measured and calculate to SNR and CNR ,the dose length product (DLP) was recorded and invert to effective dose .The image quality and radiation dose were evaluated in differ‐ent imaging condition .Results The image noise of SAFIRE reconstruction was lower than FBP reconstruction in same san parame‐ters .The increase of tube current‐time product from 100 mAs to 300 mAs ,it shows the characteristics of linear tendency .When it was on 260 mAs ,the image quality become stable .The difference between the two groups(80/140 kV ,100/140 kV)of SD of CT value by SAFIRE was significant (P< 0 .05) ,the difference of SNR and CNR between the two groups was not significant (P>0 .05) .The effective doses of group A (80/140 kV) was significantly lower than group B(100/140 kV) .Conclusion Using tube voltage of 80/140 kV combine with SAFIRE algorithm in head DECTA can ensure the image quality ,which can significantly reduce radiation dose .

0.05),but the HPPT was dose-dependently increased in 25 and 50 mg?kg -1 groups(P0.05); on the contrary ,strychnine 0.5,0.75,1.0 ?g(it) decreased the HPPT of propofol-treated mice as doses increased(P0.05). CONCLUSION Propofol can induce antinociception in hot-plate test and acetic acid-induced writhing test of mice. Spinal glycine receptors may play a role in propofol's antinociceptive properties in hot-plate test of mice.

Objective To verify the safety of non-thoracoscopic Nuss procedure,and review our experience in correction of pectus excavatum by Nuss procedure with post-implantation thoracoscopic assistance.Methods 191 patients with pectus excavatum were surgically corrected by Nuss procedure with post-implantation thoracoscopic assistance.There were 146 boys and 45 girls,The age ranged from 2.8 to 20 years with mean age was ( 6.46 ± 3.36) years.Hailer' s index was 4.68 ± 1.84.The operation was performed under Non-thoracoscopic assistance first and then with thoracoscopic observation.Results The operation in all patients had been performed successfully.The time of the operation ranged from 27 to 50 minutes with mean time was ( 32.49 ± 2.79) minutes.The average bleeding volume during procedure was ( 2.19 ± 0.87 ) ml.The durstion of follow-up was 10 to 23 months.All patients have been satisfied with their surgical correction.The postoperative complication was 13 cases( 6.81％ ).The bar outsides the pleura in both sides was 18 cases( 9.42％ ).The bar outsides the right pleura was 23cases( 12.0％ ).The bar outsides the left pleura was 17 cases( 8.90％ ).Conclusion Nuss procedure with non-thoracoscopic assistance for correction of poctus excavatum is safety if the surgeon experienced and have certain methods.Post-implantation thoracoscopic Nuss procedure is safer,and can deal with the damage caused by non-thoracoscopic assistance.

Objective To summarize the experience of diagnosis and treatment of pectus excavatum associated with congenital pulmonary disease in children.Methods The data of 91 patients with pectus excavatum associated with congenital pulmonary disease was collected from July 2002 to August 2010 in Beijing Children's Hospital.There were 64 males and 27 females.30 patients with pectus excavatum associated with congenital pulmonary cyst,congenital cystic adenomatoid malformation,pulmonary sequestration,and some severe cases of congenital lobar emphysema received the Nuss surgery and lobectomy simultaneously.Results 30 cases with pectus excavatum asseeiated with congenital pulmonary disease received simultaneous Nuss procedure and lobectomy.All cases were confirmed by pathology and recovered uneventfully.Conclusion Chest CT scan is an effective way to evaluate pectus excavatum associated with pulmonary diseases.Whether surgery is needed for the pulmonary disease depend on the specific types of disease,age and other various factors.Simultaneous surgery for pectus excavatum and pulmonary disease can lower the risk of the multiple operations,and reduce the financial burden of famihes.

Objective To evaluate the accuracy and efficiency of the Monte Carlo software in measuring the radiation dose to the patients who received the CCTA (Coronary Computed Tomography Angiography) examination.Methods A anthropomorphic chest phantom underwent CCTA using three scan parameters (tube voltage 80 kV,100 kV and 120 kV).Computer Software ImpactDose 2.0 was used to compute the chest organ dose on the basis of the three groups tube voltage CT scan characteristic,and the stimulation results of ImpactDose 2.0 software was verified by use of anthropomorphic phantom thermoluminescence dosimeter experiment method.Results For all the measured organs except for lung,the absorbed organ dose and effective dose of three groups of tube voltages of CCTA measured by the InpactDose 2.0 was lower than those as measured by anthropomorphic phantom study.The relative error of both methods was within ± 50％.Conclusions Monte Carlo software can be used to estimate the levels of radiation dose during CCTA examination with a tolerable error within the acceptable range.

Problem-based learning (PBL) teaching method combined with formative evalua-tion was used in the teaching practice of pediatrics education. This method was implemented by four phases: courses designing, group-preparing, problems-organizing and teaching practice. The method was evaluated by students' feedback and survey results of patients, teachers and teaching councilors. It was showed that the teaching effects of PBL combined with formative evaluation was better than tra-ditional teaching method in pediatrics teaching.

Objective To investigate the influence of acquisition time of C-arm cone-beam CT on image quality and radiation dose of cerebral angiography.Methods C-arm cone-beam CT of cerebral angiography was performed on the male anthropomorphic head phantom,with DynaCT imaging mode and the acquisition time of 5 s,8 s and 20 s were used.Scanning was performed with each acquisition time for three times,and VR,MIP and MPR images were reconstructed.The attenuation values and their standard deviations of intracranial segment of the internal carotid artery (ICA),middle cerebral artery(MCA),anterior cerebral artery(ACA) and uniformed brain tissues were measured to calculate the image noise,signal to noise ratio (SNR) and contrast to noise ratio (CNR).We used the image noise,SNR and CNR as the objective standard to evaluate the image quality,and One-way ANOVA analysis of variance was used to assess the difference among them.A scale with scores 1 to 5 was used to rate the quality of the reconstructed image of ICA,MCA,ACA as a subjective evaluation,the difference among the evaluation scores were analyzed using Kruskal-wallis.We recorded the dose area product (DAP) of each acquisition time and the effective dose(ED) was calculated to assess the radiation dose,the difference among them were analyzed using One-way ANOVA analysis of variance.Results In C-arm cone beam CT 20 s imaging,the SNR of intracranial segment of the ICA,M CA,ACA were 22.29± 1.41,29.36 ±0.11 and 23.13 ±2.10 respectively,in 5 s imaging13.83 ±0.61,14.65 ±0.16 and 12.79±0.19 respectively,in 8 s imaging 14.92±0.96,18.97 ± 1.24 and 16.65 ±0.46 respectively,all the results showed a significant difference (F valued 58.19,327.29,52.74 respectively,all P valued＜0.01),the CNR of 20 s imaging were higher than that of 5 s and 8 s imaging,the Noise of ICA,MCA,ACA and the uniformed brain tissues of 20 s imaging were lower than that of 5 s and 8 s imaging,all the results showed significant difference (all P valued＜0.01).The subjective evaluation scores of VR imaging of 5 s,8 s and 20 s were 3.61 ±0.49,4.06±0.53,4.72±0.45 respectively,the scores of MIP imaging were 3.42±0.50,3.83±0.65 and 4.50±0.51 respectively,the scores of MPR imaging were 2.83±0.45,3.14±0.35 and 3.67±0.49 respectively,all the results showed significant difference (x2 valued 51.29,42.25 and 43.56 respectively,all P valued ＜0.01).The DAP values in C-arm cone beam CT 5 s,8 s and 20 s imaging were (9.11 ±0.18),(13.81±0.75)and(58.62±0.62)Gy· cm2,ED values were (0.91 ±0.02),(1.38±0.75)and(5.84± 0.11) mSv,all the results showed significant difference (F valued 3 720.30 and 3 654.85 respectively,all P valued＜0.01).Conclusion The image quality and radiation dose of C-arm cone-beam computed tomography are closely correlated with acquisition time.

Objective To investigate the protective effects on the renal allografts from brain dead (BD) donor rats pretreated with bone marrow mesenchymal stem cells (MSCs).Method Three groups [normal transplant group (G1).BD transplant group (G2),and MSCs pretreated + BD transplant group (G3)] were set up.Male F344 rats served as donors and male Lewis rats as recipients.In G1,kidneys from F344 donor rats were implanted into Lewis recipients.In G2,kidneys from F344 BD donor rats were engrafted into Lewis recipients.In G3,after BD was established in F344 rats,MSCs were given intravenously to the rats.The kidneys harvested 6 h later were transplanted to Lewis recipients.Cyclosporine was intromuscularly given daily to the recipient rats for 10 days.Right kidneys were resected from recipients on day 10.Creatinine level was examined on day 14,21,28,and 35.Renal allografts harvested on day 35 were pathologically detected.The irnmunochemistry expression of interleukin (IL)-1β and tumor necrotic factor (TNF)-α in renal allograft tissue was tested.Result Serum creatinine levels in G2 were remarkably higher than those in G1 and G3 (P＜0.01) on day 14,21,28,and 35 postoperatively.The creatinine levels on the above mentioned time points had no statistically significant difference between G3 and G1 except on day 21.Postoperative pathological changes in G2 of both pronounced infiltration of mononuclear cells and tubular epithelia[inflammation were notably increased in renal allografts as compared with those in G1 and G3.There was no obvious difference between G1 and G3 in infiltrated mononuclear cells and tubular epithelial inflammation.Positive expression levels of both IL-1β and TNF-α in glomerular,tubular and interstitial epithelial cells were statistically enhanced in G2 as compared with those in G1 and G3 (H =7.210,P =0.027),while there was no statistically significant difference in the expression of both IL-1[β and TNF-α between G1 and G3.Conclusion Brain dead donor rats pretreated with bone marrow MSCs might reduce renal allograft injury via decreasing both inflammatory cell infiltration and IL-1β and TNF-α expression.

Objective To compare the differences of pulmonary nodule detection rates between iterative reconstruction (sinogram affirmed iterative reconstruction,SAFIRE)algorithm and filtered back projection (FBP) algorithm in chest CT, and to evaluate the detection accuracy.Methods Three groups of tube voltage values of 80,100,and 120 kV were defaulted on the new dual-source CT,with automatic mAs care dose 4D technology, the chest phantom with simulated pulmonary nodules was scanned, then the images were reconstructed with FBP and SAFIRE (grade 1-5 ),respectively. The detection rates of simulated pulmonary nodules in the chest CT images reconstructed of SAFIRE (grade 1-5 )and FBP were compared, and their diameters and CT values were measured.Results With the same tube voltage, no significant difference was found in the detection rate of simulated pulmonary nodules between SAFIRE (grade 1-5 )and FBP (P>0.05 ), the diameter deviation of simulated nodules of SAFIRE (grade 3 )was less than FBP, and the difference in the average CT value of the simulated nodules between SAFIRE (grade 3)and FBP was not statistically significant (P>0.05);the simulated nodule detection rate of 100 kV was equivalent to the detection rate of 120 kV,the simulated nodule (-800 HU and 3 mm )detection rate of 80 kV was less than that of 120 kV;as the tube voltage reduced,or simulated nodule diameter decreased,or the density of simulated nodule reduced,the nodule’s diameter deviation was increased. Conclusion Compared with FBP,the capabilities of SAFIRE in pulmonary nodule detection in different densities and different sizes are same,and SAFIRE algorithm is helpful for accurate displaying of pulmonary nodules,and it can be used for low-dose CT lung cancer screening program.