In this paper, a method for dose calculation with pencil beam kernels constructed by point kernel superposition was proposed to accelerate the dose calculation during intensity optimization iteration. With this method, the direct aperture optimization method can be integrated in the planning system based on point kernel convolution/superposition model. The dose calculation time was also reduced during the iteration. From the result of the phantom and clinical patient data test, it was concluded that this method could be used for the intensity optimization of iteration dose calculation as the satisfied precision due to the optimization result coherence obtained. By implementing the method in the planning system product based on point kernel convolution/superposition model, a lot of additional research and development works for the pencil beam dose calculation model as well as the product maintenance cost can be avoided.
Algorithms ; Humans ; Models, Theoretical ; Phantoms, Imaging ; Radiotherapy Dosage ; Radiotherapy Planning, Computer-Assisted ; Software

Objective: To evaluate the impact of the number of negative lymph nodes on disease free survival (DFS) of patients with locally advanced gastric cancer. Methods: A total of 485 patients who underwent surgery for gastric cancer were enrolled in this study. We analyzed the data of these patients including complete information of follow-up and definite postoperative pathological results. The disease free survival of all patients was more than 6 months and was analyzed according to the pathological stage respectively. COX regression analysis was performed to screen the independent prognostic factors. Kaplan-Meier method was used to draw the disease free survival curve and the disease free survival rate was compared among subgroups. Results: Cox regression analysis showed that the disease free survival rate of gastric cancer patients with pathological stage T_3N_(0～2)M_0 was significantly associated with age, degree of tumor differentiation, tumor location as well as the number of negative lymph nodes. In the T_3N_0M_0 subgroup, when the number of negative lymph nodes was 1 to 4 and 5 or more, the 2-year disease free survival rate was 8.3% and 55.6%, respectively, and the 3-year disease free survival rate was 0 and 24.9%, respectively (P=0.025).In the T_3N_1M_0 subgroup, when the number of negative lymph nodes was 3 or less, 4 to 9, and 10 or more, the 2-year disease free survival rate was 17.3%, 39.1%, and 52.6%, respectively, and the 3-year disease free survival rate was 4.2%, 6.0%, and 17.1%, respectively (P<0.001). In the T_3N_1M_0 subgroup, when the number of negative lymph nodes was 7 or less and 8 or more, the 2-year disease free survival rate was 11.5% and 35%, respectively, and the 3-year disease free survival rate was 0.8% and 5%, respectively (P=0.015).Conclusion: For gastric cancer patients with pathological stage T_3N_(0～2)M_0, the number of negative nodes could reflect the level of regional lymph node dissection. The number of negative nodes can be an index for evaluation of the accuracy of pathological staging and is considered as an independent prognostic factor for disease free survival of gastric cancer patients.

Objective:To investigate the clinical efficacy of every 3-week regimen of oxaliplatin (OXA) plus 5-fluorouracil (5-FU)/leucovorin(CF)as postoperative adjuvant chemotherapy for colorectal cancer.Methods:Ninety eight patients with stage Ⅱ to stage Ⅲ colorectal cancer received every 3-week OXA plus 5-FU/CF adjuvant chemotherapy for six cycles after resection surgery. All the patients received a complete reexamination every 3 months after the end of adjuvant chemotherapy. The disease-free survival period and 1- and 2-year disease-free survival rates were observed.Results:The total 2-year disease-free survival rate was 74.5%. It was 87.0% for stageⅡpatients and 63.5% for stage Ⅲ patients. The main adverse reaction included peripheral neurotoxicity, neutropenia and diarrhea at grades Ⅰ to Ⅱ. Grades Ⅲ to Ⅳ adverse reactions occurred rarely.Conclusion:The every 3-week OXA combined with 5-FU/CF adjuvant chemotherapy regimen had definite efficacy and good tolerance, which was a rational choice of postoperative adjuvant chemotherapy for colorectal cancer.

Objective: To study electrocardiogram (ECG) monitoring assisted ultrasound guidance for modiifed seldinger technique (MST) in peripherally inserted central catheters (PICC) and to estimate the accuracy of ECG for presenting catheter tip location. Methods: The patients were connected with ECG monitoring system, the guide wire was connected to RA electrode in ECG monitor for leading out P wave of intracavitary ECG. The location of catheter tip was estimated by P wave characteristics and then, estimated ECG result was further compared with chest X-ray presented catheter tip position. The coherence of catheter tip position between ECG and chest X-ray was compared, the sensitivity and speciifcity of ECG estimation were calculated. Results: There were 100/104 patients showed speciifc P wave in ECG, the coherence to chest X-ray was 96.2%; 4 patients had no speciifc P wave and their chest X-ray presented that the catheter tip position at upper superior vena cava in 2 patients, at lower superior vena cava in 1 patient, at contralateral brachiocephalic vein in 1 patient. The accuracy of 2 methods had no statistic meaning. ECG estimation for PICC catheter tip position had the sensitivity at 99% and speciifcity at 100%. Conclusion: ECG monitoring may determine the catheter tip position for MST in PICC guided by ultrasound. It doesn’t need chest X-ray, without additional trauma and no radioactive contamination, which make PICC catheters get more extensive application in clinical practice.

Objective To assess the efficacy of the mixtures of different concentrations of ropivacaine(R) and chloroprocaine(C)for epidural anesthesia in patients undergoing hysterectomy.Methods Sixty ASAⅠorⅡpatients aged 27-56 weighing 45-75 kg undergoing elective hysterectomy were randomly divided into 4 groups(n= 15 each);groupⅠ0.75% R alone;groupⅡ0.5% R-1% C;groupⅢ0.5% R-1.5% C and groupⅣ0.75% R+1% C.The epidural catheter was placed at L_(2,3)interspace and advanced 3.5 cm into the epidural space in cephalad direction.A total of 22 ml of epidural solution was injected in each group.The onset time,block height and duration of sensory block and the onset time,degree and duration of motor block(using Bromage scale)were assessed.The use of supplementary drugs(ketamine and ephedrine)and side effects were recorded.Results The onset time of sensory and motor block was significantly shorter in groupⅡ,ⅢandⅣthan in groupⅠ(0.75% R alone).The duration of sensory and motor block was significantly shorter in groupⅡandⅢthan in groupⅠandⅣ.The incidence of hypotension was significantly increased but the incidence of discomfort produced by traction on the viscera during operation was reduced in groupⅣas compared with groupⅠ.Conclusion The anesthetic efficacy of epidural 0.5% ropivacaine is significantly enhanced when mixed with 1.0% or 1.5% chloroprocaine.

Objective: To observe the effects of Zhichuanxiaoke strong solution on the immunity and irritability of mice. Methods: The carbon clearance index and the content of serum hemolysin of mouse were determined by colorimetry. The survival time of mouse was measured through hypoxia tolerance test under ordinary pressure and the anti fatigue swiming test. Results: Zhichuanxiaoke Strong Solution could obviously increase the carbon clearance index and the content of serum hemolysin, enhance the anti hypoxia ability and prolong the swiming time of mouse. Conclusion: Zhichuanxiaoke Strong Solution can increase physical immunity and the ability of auti irritability.

Continuous electroencephalographic monitoring (CEEG) has been used for clinical monitoring of acute cerebrovascular diseases for nearly 3 decades,but it has not been used as a conventional monitoring approach in clinical practice.In recent 15 years,CEEG technology has made considerable progress,especially in the field of real-time monitoring of acute cerebral ischemia and epilepsy,which has provided a new possible direction for the diagnosis and treatment of acute cerebrovascular diseases.The article briefly comments the application of CEEG in acute cerebrovascular diseases.

Objective To explore the expression of interleukin 13(IL-13) mRNA in peripheral blood mononuclear cells (PBMCs) and its association with serum C-reaction protein(CRP) in patients with ulcerative colitis(UC). Methods IL-13 mRNA expression in PBMCs was detected by RT-PCR in patients with UC(21 cases of active UC and 10 cases of quiescent UC)and 20 healthy subjects. At the same time, the serum level of CRP was detected by ELISA. Results The expression level of IL-13 mRNA in PBMCs of patients with active UC was significantly lower than that in PBMCs of patients with quiescent UC and healthy subjects (6.45?1.23 vs 14.72?2.12 or 15.17?2.38,P0.05). The expression level of IL-13 mRNA in PBMCs of active UC patients was negative correlation with serum level of CRP (r=-0.589,P

The paper describes the short and medium term (within 2 to 5 years) priorities that any region in China right now faces in working out and implementing its regional health planning, viz. the coordinated development strategy of medicine and health, medical security and social economy. The authors hold that to achieve the coordinated growth of the health cause and society, it is imperative to overcome in the short run logically related obstacles in four aspects: ineffective solution to the apparent problems followed with interest by both the social and health sectors and lack of effective operating conditions accompanying medical insurance reform, both resulting in the lack of a driving force in the reform within hospitals; difficulty in achieving breakthroughts in the development of the health cause; and the probability of a regional health planning becoming a mere formality because of the above factors. In addition, the fact that reform of medical and health institutions in their setup and ownership of property rights lags behind macroscopic social economic reform obscures the explanation of and solution to the above problems. Based on the research results, the paper sets forth the priorities in short and medium term planning.

PURPOSE Anti-cancer drug treatment induces cell death by apoptosis, whether the gene p53 undergoes mutant changes is found to have a close relationship with anti-cancer drugs. The aim of this work is to investigate the role that p53 plays in the 5-FU-induced apoptosis of colorectal cancer cells in vitro. METHODS Thirty-nine col-orectal cancer samples from patients were treated with 5-FU (10?g/ml) and folinic acid (5?g/ml. 10?g/ml) in vitro, using the in situ Terminal Deoxynucleotidyl Transferase assay (TDT) to detect the chemosensitivity. p53 mutations from tumor DNA were detected, after amplication by PCR of exons 5 to 8. by non-radioactive single-strand conformation polymorphism(PCR-SSCP). RESULTS p53-gene mutations were observed in 43. 6% (17/39) of colorectal carcinomas. When TDT assay was used to detect the tumor apoptotic rate, cells with mutated p53 had less chemosensitivity than those without (16. 4% ?4. 89% vs 26. 6%? 6. 80% P