0.05). Conclusions Pathological changes may occur after interstitial radiotherapy at the dose of 120 Gy,but there are no early irreversible radioactive injuries,such as bleeding and perforation.

Objective To investigate the value of magnetic resonance imaging (MRI)-based intravenous thrombolysis in patients with wake-up ischemic strokes (WUIS).Methods Patients presenting within 12 hours of acute stroke symptom onset and those with WUIS confirmed by CT,excluding intracranial hemorrhage,were encouraged to perform an emergent brain MRI scan to confirm the diagnosis of hyperacute ischemic stroke (hyper-intense in DWI without hyper-intense change in T2WI or fluid attenuated inversion recovery (FLAIR)).These patients then received intravenous thrombolytic therapy with recombinant tissue plasminogen activator (rt-PA).All patients were divided into either stroke presenting within 12 hours or WUIS.The clinical outcomes were assessed by the modified Rankin scale (mRS) and the Barthal index (BI) at baseline and at 90 days after the thrombolysis therapy.Results Two hundred and sixty-one patients (261/563,56.4％) had confirmed diagnosis of hyperacute ischemic stroke (WUIS,n =73,73/121 =60.3％ vs within 12 hours,n =188,188/342 =55.0％).Altogether,192 patients (139 in within 12 hours group,and 53 in WUIS group) received intravenous thrombolytic therapy with rt-PA.No significant differences were found between the 2 groups at the baseline characteristics and at 90 days outcomes after the thrombolysis therapy(x2 =1.296 and 1.473,P =0.538 and 0.489,respectively).Also no significant differences were found in the incidence rate of secondary hemorrhage (including both of asymptomatic and symptomatic) and mortality rate between the 2 groups.Conclusion MRI-based intravenous thrombolysis is safe and effective in the treatment of patients with hyperacute WUIS.

Objective To investigate the dose distribution of esophageal stents carrying different diameters of radioactive 125I seeds in tumor target area. Methods A laser scanner was used to scan a piece of blank paper on which circles of 12 mm, 14 mm and 16 mm diameter and a 5 cm scale were drawn. The data were stored in JPEF format on the computer desktop. According to the circular diameter, simulations of the corresponding esophageal stents were established, which were divided into group A, group B and group C. By using image conversion program, 17 images with 5 mm slice-distance were created for each group; the images were transmitted to the computer treatment planning system (TPS) to simulate the 8 cm long esophageal stents of different diameters. TPS was used to sketch the gross tumor volume (GTV) in order to simulate the esophageal stent border that was used as the inner boundary of GTV, which was expanded 0.5 cm outward to be used as the external boundary of GTV. Beginning from the fifth level, the 4 cm-long GTV was drawn with circles. Setting the same prescription dose, from the fifth level to the thirteenth level the 125I seeds with 0.3, 0.4, 0.5, 0.6, 0.7, 0.8 and 0.9 mCi were successively loaded on the simulation of the esophageal stents. The distance between 125I seed layers was 1 cm; the average number of seeds distributed on each layer was 4 particles. The dose volume histogram (DVH) was obtained. The D90 (the dose received by 90% of the target) and V90 (the percentage of the GTV volume receiving 90% the prescription dose) were recorded.Result s The arithmetic mean D90 of group A, B and C was (77.24 ±19.92) Gy, (69.56 ±25.27) Gy and (56.38±20.08) Gy respectively, and no statistically significant differences existed between each other among the three groups (F=0.84,P=0.44). The V90 of group A, B and C was (77.76±30.73)%,(76.79±25.92)%and (64.10 ±32.49)% respectively, and no statistically significant differences existed between each other among the three groups (F=0.46,P=0.64). Conclusion When the diameter of radioactive esophageal stent is 12 mm, the activity of 125I seed of 0.6 mCi is recommended. When the diameter of radioactive esophageal stent is 14 mm or 16 mm, the activity of 125I seed of 0.7 mCi is recommended. Nevertheless, when the diameter of radioactive esophageal stent is 16 mm, distribution of every five 125I seeds on each layer is strongly recommended. These three kinds of esophageal stent diameter have no significant effect on the dosimetric parameters.

Objective To investigate the safety and feasibility of different puncturing approaches in the performance of CT-guided 125I seed implantation for the treatment of retroperitoneal malignant tumors. Methods The clinical data of twenty-five patients with retroperitoneal malignant tumors, who had underwent CT-guided 125I seed implantation, were retrospectively analyzed. The puncturing approaches included trans-hepatic route, trans-gastric route, trans-duodenal route, and through mesentery and through thoracolumbar iliocostalis. The malignant tumors included retroperitoneal lymph node metastases (n=21) and pancreatic cancer (n=4). Preoperative full bowel preparation was carried out in all patients, and treatment planning was formulated by using treatment planning system (TPS) before the procedure. Under CT guidance, proper puncturing approach was selected according to lesion's location. One to 3 needles were used to implant 125I seeds. Immediately after 125I seed implantation, CT scanning was performed to check the distribution of 125I seeds. Results CT-guided 125I seed implantation was successfully completed in all patients. The puncturing approaches used in this series included trans-hepatic route (n=21), trans-gastric route (n=9), trans-duodenal route (n=2), through mesentery (n=2) and through thoracolumbar iliocostalis (n=5). After the operation, no procedure-related complications such as bleeding, peritonitis, hematemesis or melena occurred in all patients. The postoperative 125I particle number, total activity and peripheral dose (D90) were not significantly different from the preoperative data. Conclusion The use of the five puncturing approaches mentioned above is clinically safe and feasible. Strict perioperative management measures should be carefully executed when through cavity organ implantation is employed.

Objective To discuss the feasibility, efficacy and complications of CT-guided 125I seed implantation for the treatment of lymph node metastasis nearby the iliac vessels.Methods The clinical data of twelve patients with para-iliac vessel lymph node metastasis, who had been treated with CT-guided 125I seed implantation, were retrospectively analyzed. A total of 12 lesions were detected; the diameter ≤6 cm was seen in seven lesions, and the diameter >6 cm was seen in five lesions. Using computer treatment planning system, the source distribution was calculated. Under CT guidance 125I seeds with the activity of 0.4-0.7 mci were implanted into the metastatic lymph nodes with a seed interval of 0.5-1.0 cm. CT scan was performed immediately after implantation to check the distribution of seeds as well as the possible complications. After the treatment, D90 (90%prescription dose received by target volume) was ≥75 Gy in 6 patients and <75 Gy in other 6 patients. Two months after the treatment CT reexamination was employed, and imaging evaluation was conducted according to WHO Response Evaluation Criteria in Solid Tumors. Results CT-guided 125I seed implantation was successfully accomplished in all 12 patients. Two months after the treatment, the evaluation of the therapeutic effect showed that complete remission (CR) was obtained in 0 patient, partial remission (PR) in 8 patients, stable disease in 3 patients and progress disease in one patient;and the total effect rate(CR+PR) was 66.7%. The local control rate was 91.7%. In eight patients the pain that was caused by metastatic lymph nodes was significantly relieved within 1-14 days after 125I implantation treatment. Before the treatment three patients had lower limb edema, and in two of them the lower limb edema was obviously relieved within 1-14 days after the treatment. All patients were followed up for 3-39 months, and the median follow-up time was 11 months. One-year survival rate was 41.7%. No severe complications such as massive hemorrhage, infection, myelosuppression or seed displacement occurred. Conclusion For the treatment of para-iliac vessel lymph node metastasis, CT-guided 125I seed implantation is safe and feasible. Better curative effect may be achieved when the diameter of the metastatic lymph node is<6 cm and the peripheral radiation dose is>75 Gy.

Objective To explore the clinical efficacy of CT-Guided radioactive 125I seed implantation in treating retroperitoneal lymph node metastases. Methods Eighteen patients with retroperitoneal lymph node metastases (20 lesions in total) received CT-guided radioactive 125I seed implantation. Treatment planning system (TPS) was used to formulate the therapeutic protocol. The radioactive activity of 125I particle ranged from 1.11 × 107-2.96 × 107 Bq (0.3-0.8 mCi) and the matched peripheral dose (MPD) was 60 -100 Gy. Postoperative dosimetry was routinely performed for all the patients in one week. Postoperative D90 (90%dose received by target volume) was 53 -107 Gy. The patient’s clinical benefit response (CBR), two-month local tumor control rate and one-year survival rate were evaluated, and the complications were recorded. Results All the patients were followed up for 2 -15 months with a median time of 5 months. The one-year survival rate was 22.2%. The clinical benefit rate, overall effective rate and two-month local tumor control rate were 72.2%, 70.0% and 90.0% respectively. No serious complications occurred in all patients. Conclusion For the treatment of retroperitoneal lymph node metastases, CT-guided radioactive 125I seed implantation is mini-invasive with satisfactory short-term effect and fewer complications. Therefore, this technique is a relatively safe therapeutic means.

Objective To study the dose distribution in tumor target of radioactive esophageal stent covered with 125I seeds which are arranged at different distance. Methods According to the longitudinal and horizontal distance between the 125I seeds, the experiment was divided into group A (0.5 cm), group B (1.0 cm) and group C (1.5 cm). A sheet of white paper, on which a 2cm diameter circle was drawn and was marked with a 5 cm scale, was scanned with a laser scanner, and the scanning data were saved in JPEG format on the computer desktop. By using image conversion program, pictures of 17 layers with the layer space of 5 mm were created. The picture was transmitted to the computer treatment planning system (TPS) to simulate a 2 cm diameter and 8 cm length esophageal stent. Using TPS to delineate the tumor target area (gross tumor volume, GTV), which was used as the simulation of the inner boundary of the tumor target area, outward expansion of 0.5 cm being regarded as the outside border. An annular and 6cm length tube was delineated and it was used as the target area, and the same prescription dose was set, and in each group 125I seeds of 0.3, 0.4, 0.5, 0.6, 0.7, 0.8 and 0.9 mCi were successively loaded on the simulation of esophageal stent. With the help of TPS the DVH graph was obtained, and the D90 (the dose received by 90% of the target) and V90 (the percentage of the GTV receiving 90% the prescription dose) of the three groups were determined. The results were statistically analyzed. Results The arithmetic mean values of D90 of group A, B and C were (217.15± 19.92), (89.16±32.44) and (31.68±11.52) Gy respectively (F=159.18, P<0.05); and the arithmetic mean values of V90 of group A, B and C were (100.00±0.00)%, (86.47±21.36)%and (29.33±21.54)%respectively (F=32.11, P<0.05). Conclusion The 2 cm-diameter radioactive esophageal stent covered with 125I seeds, which have o.6mci activity and are arranged at 1.0cm distance in both longitudinal and horizontal directions, should be recommended in clinical practice.

ObjectiveTo investigate the characteristic parameters and variation of acoustic startle reflex (ASR) and conditioning response (CR)during the acquisition of delay-trace eyeblink conditioning.Methods15healthy Kunming mice were randomly divided into 3 groups:single-task DEBC group ( n =5 ) ; single-task TEBC group ( n =5) ; dual delay/trace group ( n =5).Three groups received paired training of tone conditioned stimulus(CS)in different audio frequency (TEBC groups:2KHz; DEBC group:1KHz) and a 100 ms comeal oxygenpuff unconditioned stimulus(US).Then observed the characteristic parameters of ASR and CR.ResultsAfter pairing training for 10 days,ASR rate( ASR％ ) of single-task groups ( 10th day (38.00 ± 8.64) ％ and (38.55 ±12.41 ) ％ respectively,time effect:F =4.574,P =0.008 ; group effect:F =2.021,P =0.193 ) and dual delaytrace group ( 10th day (47.95 ± 14.23 ) ％ and (62.01 ± 9.03 ) ％ respectively,time effect:F =5,547 P =0.013 ;group effect:F =0.738,P =0.415) changed significantly with the following training but between single-task groups or dual delay-trace group.CR rate ( CR％ ) of single-task groups ( 10th day were (45.4 ± 5.39) ％ and (65.6 ± 6.77) ％ respectively,time effect:F =9.558,P =0.000 ; group effect:F =5.117,P =0.054 ) and dual delay/trace group ( 10th day (57.66 ± 4.34) ％ and (77.35 ± 7.36) ％ respectively,time effect:F =7.750,P =0.002 ;group effect:F=1.449,P=0.263 ) showed obvious change with the following training but between singletask groups or dual delay-trace group.Peak amplitude of single-task DEBC group ( time effect F =2.679,P =0.017 ) and dual delay-trace group ( F=3.452,P=0.034 ) had increased significantly with the following training.Peak latency showed no obvious change.ConclusionDual delay-trace conditioning procedure of classical eyeblink conditioning and single-task can be successfully established in Kunming mice.Although there are some variations,those can be controled and be weaken effect of them by taking targeted measures.

Objective To observe and analyze the role of different subfields of medial prefrontal cortex (mPFC) in the expression course of startle reflex.Methods 24 healthy male British kind of albino guinea pigs were randomly divided into 4 groups:anterior cingulated cortex lesion ( n =6) and sham-lesion ( n =6) ( Experiment 1 ) ; prelimbic cortex lesion/joint lesion of prelimbic cortex and anterior cingulated cortex(n=6) and sham-lesion ( n =6) ( Experiment 2 ).The animals were injected lidocaine ( lesion ) or physiological saline ( sham-lesion ).Each group received paired training of conditioned stimulus( CS,a tone) and unconditioned stimulus (US,a air puff),to observe the acoustic startle reflex(ASR) change of these groups.Results As the results of experiment 1 suggested,SR rate did not change significantly after anterior cingulated cortex lesion ( time effect:F =15.421,P =0.098 ; group effect:F =14.753,P =0.084).As the results of experiment 2 suggested,SR rate did not change significantly after prelimbic cortex lesion ( time effect:F =14.975,P =0.178 ; group effect:F =18.643,P =0.089).When prelimbic cortex and anterior cingulated cortex were lesioned at the same time,SR rate declined significantly and didn ' t recover with the following training ( group effect:F =67.743,P =0.009 ).ConclusionLesions of the prelimbic cortex and anterior cingulated cortex in mPFC cause the significantly decline of acoustic startle reflex( ASR),which don' t recover with the following training.This study indicates that mPFC involves in the regulation of ASR,but the regulation mechanism needs to be discussed.

Objective To investigate the safety and effectiveness of radioactive 125I seed implantation in treating recurrent cervical lymphatic metastases after radiotherapy. Methods During the period from Aug. 2011 to July 2012, 17 patients with recurrent cervical lymphatic metastases who had received radiotherapy before were admitted to authors’ hospital. The clinical data were retrospectively analyzed. A total of 23 metastatic lymph nodes were detected in the 17 patients. Brachytherapy treatment planning system (TPS) was used to formulate the number, activity and distribution of radioactive 125I seeds. The radioactive activity was 0.3 - 0.8 mCi (1.30 × 107- 2.96 × 107 Bq), and the matched peripheral dose (MPD) was 60 - 120 Gy. Guided by ultrasound and CT radioactive 125I seeds were implanted under local anesthesia. CT scanning was performed within 24 hours after the procedure. Postoperative D90 was (81.4 ± 2.1) Gy. CT examination was employed every two months to determine the tumor size and to record the complications. Results All patients were followed up for 6 months. The 6-month local control rate was 65.2%. The control rates (CR+PR) for<4 cm (n=10) and>4 cm (n=13) lymph nodes were 90%and 46%respectively, the difference between the two was statistically significant (P = 0.038). No significant difference existed between the control rate (CR + PR) and the un-control rate (SD + PD) for each lymph node group at cervical Ⅰ, Ⅱ, Ⅲ and Ⅴ grade Ⅱ was seen in 8 cases and grade Ⅰ in 7 cases. No severe complications occurred. Conclusion For the treatment of recurrent cervical lymphatic metastases after radiotherapy, radioactive 125I seed implantation is effective and mini-invasive with fewer complications. This technique is more suitable for < 4 cm solitary metastatic lymph node with clear border.