Objective To commission a Mobetron intra-operative mobile accelerator and analyze the characteristics of its electron beams. Methods The dosimetrie characteristics of the electron beams genera-ted by Mobetron accelerator were measured and compared with those generated by conventional accelerator (Primus, Siemens). M oberton accelerator can generate electron beams of nominal energies of 4,6,9 and 12 MeV. The measurement items were as followings : percentage depth dose perpendicular to water phantom sur-face and beam profiles parallel to water phantom surface, output factors, applicator leakage, electron beam at-tenuation made by lead blocks,and machine output calibration. The measurement devices included a three-dimensional ( 3 D) water scanning phantom, an electrometer, a 0.6 cm3 Farmer ionization chamber, a parallel-plate ionization chamber and solid water slabs. During measurement, all applicators of different tilt angles and diameters were attached to the machine head,and their ends were adjusted to be tangent to the phantom surface. Results Except for the 12 MeV,skin dose for all energies was no more than 90%. The skin dose was higher for Mobetron accelerator electron beams than for regular electron beams. The Dmax depth in water for a 10 cm flat applicator were 0.7,1.3,2.0 and 2.2 cm for the 4 energies,respectively. The depths of 90% dose were 1.0,1.8,2.7 and 3.6 cm, respectively. The selected flat applicator was just 1 cm larger than the tumor bed. But for the beveled applicators,the field flatness and symmetry became worse,and con-sequently,the applicator size had to be selected based on the isodose distribution. The leakage dose at 1 cm outside the applicator was 1.2% ,5.1%, 10.0% and 9.1%, respectively. The lead thickness for full block was 1.5,3.0,4.5 and 6.0 mm,respectively. Conclusions Through the commissioning of Mobetron accel-erator, the machine characteristics are understood, and the data for clinical implementation and routine quality assurance are acquired.

Objective To evaluate the dose distribution of target volume and normal tissues with different treatment planning such as three dimensional conformal radiotherapy(3DCRT) ,simplified intensity modulated radiotherapy(sIMRT) ,and intensity modulated radiotherapy (IMRT) for patients with radically resected rectal cancer. Methods Ten male patients with stage Ⅱ and Ⅲ rectal cancer after radical resection (Dixon surgery) were enrolled in this study. 3-field or 5-field 3DCRT,slMRT and 5-field or 7-field IMRT plans were performed for each patient. The dose distributions of target volume and normal tissues,conformal index(CI) and heterogeneous index(HI) were analyzed using the dose-volume histogram(Dvit). The prescription dose was 50 Gy in 25 fractions. Results The CI for PTV of IMRT and sIMRT was superior to 3DCRT. Conversely,the HI for PTV of 3DCRT was superior to sIMRT and IMRT. sIMRT and IMRT can protect the organs at risk better than 3DCRT. The mean of total MU for 3DCRT3f,3DCRT5f, sIMRT, IMRT5f and IMRTT7f was 482±13,504±11,455±42,841±36 and 884±46, respectively. Conclusions Comparing with 3DCRT plans and IMRT plans, sIMRT plan was the optimal plan for clinical practice. All of the three radiotherapy techniques can protect the rectal stump and anal canal well with the prescription dose of 50 Gy.

Objective To investigate effect and mechanism of Xuebijing administration at various concentrations on ischemia reperfusion injury (IRI) of rabbit limbs.Methods Thirty New Zealand rabbits were divided into control group (n =10),Xuebijing group Ⅰ (n =10) and Xuebijing group Ⅱ(n =10) according to random number table.Rabbit models of IRI in lower extremities were established.Each group received corresponding therapy after reperfusion:rabbits in Xuebijing group Ⅰ were firstly administered 4 ml/kg Xuebijing solution and 6 ml/kg isotonic saline; rabbits in Xuebijing group Ⅱ were administered 2 ml/kg Xuebijing solution and 8 ml/kg isotonic saline; rabbits in control group were simply administered 10 ml/kg isotonic saline.Venous blood samples were collected before reperfusion and at 1 h,2 h,4 h after reperfusion to measure coagulation parameters (APTT,Fib,INR and PT) and biochemical items (ALB,LDH and CK).Results APTT in Xuebijing group Ⅰ presented obvious improvement at 1 h and 4 h after reperfusion as compared with control group (P ＜ 0.01).PT in Xuebijing groups Ⅰ and lⅡ was significantly longer after reperfusion than that before reperfusion (P ＜0.05).Fib level in Xuebijing group Ⅰ was much higher at 4 h after reperfusion than that before reperfusion (P ＜ 0.05).ALB level at 1 hour after reperfusion showed no statistical differences from that before reperfusion in Xuebijing groups Ⅰ and Ⅱ (P ＞ 0.05).LDH and CK levels in Xuebijing group Ⅰ were much lower than those in control group after reperfusion (P ＜ 0.05).Conclusions Xuebijing injection relieves limb IRI,with better effect in Xuebijing group Ⅰ than in Xuebijing group Ⅱ.Therapeutic mechanism may be associated with its involvement in adjusting clotting function and mitigating injury of muscle tissues.

Stroke is a common neurological diseases with high morbidity,high mortality and high morbidity characteristics,which brings great suffer and economic burden to the patients and families,and has become an important research topic in contemporary medical profession.Treatment directly affects the prognosis of patients with cerebral infarction,and thus it is very important to find the most effective treatments and methods.Currently,thrombolytic therapy in acute cerebral infarction have carried out a large number of experimental studies,and achieved good results.This paper reviewed the thrombolytic therapy in acute cerebral infarctionincluding the time window,methods and drugs of thrombolysis,and the influencing factors of outcomes were also summarized and discussed.

Posterior reversible encephalopathy syndrome is a clinical imaging syndrome associated with multiple pathogenic factors.The main clinical manifestations were headache,seizures,psychotic symptoms,visual disturbance,disturbance of consciousness,etc.The parieto-occipital reversible white matter lesions are the main manifestations of the imaging.If this disease can be diagnosed and treated in time,the clinical symptoms and imaging changes of most patients can be disappeared.If the diagnosis and treatment cannot be obtained in time,it may happen some irreversible damage,serious and even life-threatening,so it is very important to strengthen the understanding,diagnosis and treatment of this disease.At present,the pathogenesis of the disease is still not clear,now reviewed its pathogenesis and imaging manifestation in order to strengthen the clinician's understanding of the disease's pathophysiological mechanism and improve the level of diagnosis.

Objective To study and compare the effects and mechanisms between the Xuebijing injection and Danshen injection on ischemic-reperfusion injury of rabbit limb .Methods 30 New Zealand rabbits were randomly divided into control group ,Xuebi-jing group and Danshen group ,with 10 in each group .The Crinnion model of ischemic-reperfusion injury of rabbit limb was used . Each group was treated correspondingly after the blood flow was restored .Xuebijing group and Danshen group were treated with 4 mL/kg Xuebijing injection 2 mL/kg Danshen injection in saline with 10 mL total volume .Control group was treated with 10 mL sa-line .Before releasing clip and 1 h ,2 h and 4 h after reperfusion ,the blood samples were collected for detecting clotting function (APTT ,FIB ,PT-INR ,PT) ,biochemistry items (ALB ,LDH ,CK) ,MDA level and SOD level .Results Compared with control group ,the APTT of Xuebijing group in 1 h and 2 h and Danshen group in 4 h after reperfusion improved significantly (P<0 .05) . The PT of Xuebijing group after reperfusion extended significantly compared with the PT before reperfusion (P<0 .05) .The FIB level of Xuebijing group and Danshen group in 4 h after reperfusion was much higher than before (P<0 .05) .The LDH and CK level of Xuebijing group after reperfusion was much lower than that of control group (P< 0 .05) .The MDA level of Xuebijing group in 2 h and Danshen group in 1 h ,2 h after reperfusion was much lower than that of control group (P<0 .05) .The SOD activ-ity of Xuebijing group in 1-4 h and Danshen group in 2 h after reperfusion was much higher than that of control group (P<0 .05) .Conclusion Xuebijing injection and Danshen injection have the relieving effect on the limb ischemic-reperfusion injury by ad-justing clotting function and decreasing free oxygen radicals .In terms of relieving the injury of muscle tissue ,the effect of Xuebijing injection might be better than Danshen .

Objective To identify the differentially expressed genes in cardinal ligament between patients with pelvic organ prolapse ( POP) and postmenopausal women without POP by Human Genome Expression Chip and explore the potential molecular mechanism involved in POP.Methods From January to May,2007,cardinal ligament samples were obtained from 3 postmenopausal patients with POP-Q stage Ⅲ and 3 postmenopausal patients underwent hysterectomy due to other benign gynecologic diseases without POP in Peking Union Medical College Hospital.HE and Masson's trichrome staining was used to verify tissue origin and inspect histological changes.Those differentially expressed genes in cardinal ligaments were identified by Human Genome Chip and further interrogated with Gene Ontology (GO) and Pathway Analysis.Those remarkable expressed genes were confirmed by qRT-PCR.Results Alterations of ligament architecture in POP patients included disarrangement and collapse of smooth muscle bundles and collagen fibers.A total of 179 differentially expressed genes were screened between POP and non-POP cardinal ligament tissue,including 20 functional unknown genes.A total of 107 genes were upregulated in POP group,while 72 genes downregulated.Those differentially genes were revealed associated with multiple functional proteins and metabolic pathways by biological analysis.Among these,Wnt signaling pathway exhibited the most remarkable changes.Real-time quantitative PCR showed the genes of COL1Al,DKK1,SFRP1,FZD5,WNT16b in POP group (2.98 ±1.40,3.03 ±0.48,8.13 ±4.42,5.19 ±3.50,12.40± 3.88) were upregulated significantly compared with non-POP group (1.09 ±0.08,1/20 ±0.18,0.41 ± 0.51,0.87 ±0.24,1.40 ±0.47; P < 0.05 ).Conclusions The pathophysiology of POP is complex and associated with multiple functional proteins and metabolic pathways.Among these,the antagonist DKK1,SFRP1 in Wnt signaling pathway may contribute to a neurodegenerative role in POP development.

Objective To investigate the mechanism and role of ?-ray of 103Pd in the treatment of biliary duct cancer.Methods A series of biliary duct cancer cells were treated with different ?-ray dose,and MTT [3-(4,5-dimethy thiazol-2-yl)-2,5-diphenyl terazolium-bromide] technique was used to determine the inhibition rate of ?-ray of 103Pd on the biliary duct cancer cells;and electron micro-technique,DNA agarose gel electrophoresis and flow cytometry to evaluate the morphological characteristics and apoptosis rate of the biliary duct cancer cells were also used.Results The ?-ray radiation of 103Pd resulted in significant inhibition of the biliary duct cancer cells.The features of biliary duct cancer cells apoptosis(e,g:apoptic bodies,DNA ladders band hypodiploid DNA peak) could be seen in the group with lower dosage(5.333mci),and cell necrosis was seen in higher dosage(more than 6.645 mci).Conclusions The ?-ray radiation could induce apoptosis of the biliary duct cancer cells,but with dose dependence,and apoptosis can be an important mechanism for radiation treatment of biliary duct cancer.

Objective To explore the characteristic of ACE gene I/D polymorphism in Han broad jumpers .Methods Distribu‐tion of ACE gene I/D polymorphism for broad jumpers was analyzed by PCR ,DNA sequencing ,Hardy‐Weinberg and SPSS ,and the results were compared with that of normal people .Results There were II ,DD and ID in gene ACE 16 ,and the Hard‐Weinberg re‐sults showed that the subjects were group representative .The ACE DD genotype and D allele in broad jumpers was statistically higher than normal controls (P<0 .05) .Conclusion The results suggest that ACE DD genotype and D allele are associated with training sensitivity of broad jumpers and could be the molecular marker for athletes choosing genetically .

Objective To investigate the characteristics of spinal injury caused by earthquake as well as to improve its therapeutic ability by comparatively studying the medical records of the inpatients with spinal injuries caused by Wenchuan earthquake and the inpatients with spinal injuries in peace time.Methods Medical records of inpatients with spinal injuries were extracted from 5.12 earthquake injury database(earthquake group) and medical records of the patients with spinal injuries firstly admitted to Daping Hospital between 2001 and 2007 were extracted from Chinese trauma database systems (control group).The epidemiological characteristics of the two groups were comparatively studied,including gender,age,injury causes,injury severity,treatments and outcomes.Results (1) The incidence of spinal injuries in the earthquake group was 16.7％ (524/3145),which was significantly higher than that (6.4％,682/10644) in control group (P＜0.01).(2) The female ratio in the earthquake group was significantly higher than that in the control group (57.4％:31.8％) (P＜0.01).(3) The age range of the earthquake group was (47.9 ±20.9) years.The wounded number presented an undulately rising trend in the earthquake group as the growth of age,while it showed a parabolic distribution in the control group.(4)The main causes for spinal injuries were crush injury (69.3％) and multi-factor injury (2.8％) in the earthquake group,while slipping up/fall (56.0％) and traffic accidents (23.6％) were the main causes in the control group.(5) There were 82.3％ of the earthquake group that were combined with multiple injuries and 48.1％ combined with at least two injuries,while the control group accounted for only 28.9％ and 12.0％ respectively.The NISS (new injury severity score) in the earthquake group was significantly higher than that in the control group [(11.6±8.8) points vs (7.5±4.8)points](P＜0.01).Meanwhile,the proportion of NISS≥16 in earthquake group was significantly higher than that in the control group as well (P＜0.01).(6) The length of hospital stay of the wounded in the earthquake group was significantly longer than that in control group [(40.5±24.5)d VS (23.9±26.7)d](P＜0.01).The treatment inefficiency rate in the earthquake group was higher than that in the control group (9.2％ vs 4.8％) (P＜0.01).Conclusions The earthquake group has a higher proportion of spinal injuries,female and elder cases,and combined injuries,a much severer injury,a longer length of hospital stay,and a higher treatment inefficiency rate,as compared with the control group.In the earthquake relief,more importance should be attached to salvage,diagnosis,transfer regulation and missed diagnosis,misdiagnosis and secondary injury should be avoided so as to improve the treatment level of the spinal injuries in earthquake.