Objective To investigate the value of optimizing the thoracic CT scanning dose on reducing radiation dose.Methods 50 patients were undergone CT scanning using CARE Dose 4D technique,the mAs of each slices,CT dose index of volume(CTDIvol) and images qualities were evaluated respectively.And the results were compared with traditional thoracic CT scanning(200mAs,15.31mGy).Results Compared with routine sequence,the exposure dose of singe-slice was decreased by 48.2% when the CARE Dose 4D technique was used(maximal decreasing 84%),CTDIvol was reduced about 32.98%(maximal reduction of 56.5%),there was statistically significant difference(P

BACKGROUND: Schwann cell-derived neurotrophic factor is a bioactive protein isolated and purified from the kytoplasm of Schwann cell. It can obviously maintain the survival of spinal cord anterior horn motor neuron and promote the regeneration of peripheral nerve.OBJECTIVE: To observe the protective effect of Schwann cell-derived neurotrophic factor on the high injury of peripheral nerve-induced apoptosis of sensory neurons in spinal dorsal root ganglia.DESIGN: Randomized and controlled animal experiment.SETTING: Shenzhen Second People's Hospital.MATERIALS: Totally 30 3-week-old SD infant rats, of clean grade and either gender, were used in this experiment. They were randomly divided into neurotrophic factor group and control group with 15 rats in each one.Left sides of the animals in both two groups were set as normal sides and right sides as injured sides.METHODS: This experiment was carried out at the Experimental Animal Center, Medical College of Sun Yat-sen University from May 2003 to July 2003. ① L4.5 nerve root high-mutilation animal models were developed on the rats in two groups. Proximal nerve stump was connected with silicone tube. According to grouping, 60 mg/L Schwann cell-derived neurotrophic factors and 20 μL normal saline were injected into the silicone tubes respectively. Two ends of silicone tube were enveloped with vaseline.② Sample collecting was conducted at postoperative 4 weeks, survival rate and morphological change of sensory neurons in dorsal root ganglia of injured nerve was observed.MAIN OUTCOME MEASURES: ① Gross observation of sciatic nerve regeneration at injured side of the rats in two groups ② Survival of sensory neurons in dorsal root ganglia ③ Morphological change of sensory neurons in dorsal root ganglia.RESULTS: All the 30 rats entered the stage of result analysis. ① Gross observation of sciatic nerve regeneration: In the neurotrophic factor group,nerve new born axon grew along silicone tube, with 1cm in length; there were few and thin newborn axons in control group with 0.8 cm in length.② Survival of neuron in dorsal root ganglia of the rats in two groups: There was little fibrous tissue proliferation in the dorsal root ganglion in neurotrophic factor group. The loss of neurons was not obvious and the survival rate was 91.8%. Obvious fibrous tissue proliferation appeared in the dorsal root ganglia in control group, and a great many neurons were lost with the survival rate of 58.6%. Survival rate of neurons was 33.2% higher in neurotrophic factor group than in control group (P ＜ 0.01 ). ③ Morphological change of neurons in dorsal root ganglia: The diameter and area of neurons in dorsal root ganglia were significantly lower in control group than in neu rotrophic factor group and normal side [(21.8±1.4) μm,(373.1±50.9) μm2 vs (24.8±1.1) μm, (482.8±42.2) μm2 and (24.5±1.3) μm, (471.5±51.4) μm2,P ＜ 0.01], while there were no significant difference in diameter and area of neurons between neurotrophic factor group and normal side(P ＞ 0.05).CONCLUSION: Schwann cell-derived neurotrophic factors have obvious neurotrophic bioactivity for sensory neurons in the injured dorsal root ganglia.

BACKGROUND: Schwann cell derived neurotrophic factor, which is isolated and purified from the kytoplasm of Schwann cell with the relative molecular mass of 58000, is a kind of neurotrophic substance possessing obvious neurotrophic activity. It can be against neurovirulent substance of nitrogen monoxidum.OBJECTIVE:To create root avulsion animal models and observe the protective effects of Schwann cell derived neurotrophic factor (SDNF) on motoneurons of spinal anterior horn from spinal root avulsion induced cell death.DESIGN: Repeated observation and measure.SETTING: Third Department of Orthopaedics, Second People's Hospital of Shenzhen; Department of Micro-surgery , First Hospital Affiliated to Sun Yat-sen University.MATERIALS: This experiment was conducted at the Experimental Animal Center of Medical College of Sun Yat-sen University from March to May 2003. Twenty Sprague-Dawley rats with the age of 3-4 months, of clean degree, were selected and divided randomly into experimental group of Schwann cell derived neurotrophic factor and control group of normal saline with 10 rats in each group. The right side was injured, and the left side was intact served as normal control side.METHODS : ①A rat model of C6,7 spinal root avulsion induced motoneuron degeneration was established. ② A small piece of gelfoam presoaked in 40 μL SDNF solutions (1 g/L) was placed in contact with the injured spinal cord in the animals of the experimental group. Normal saline was added as the same way as above in the animals of the control group. ③ A silica pipe was put on the surface of gleform, one end of the silica was sutured to the glefoam , and the other end wasfixed subcutaneously with vaselinum. Local intramuscular injection of penicillinum was performed on the wound following closing the incision. All rats received an injection (20 μL) of either SDNF or normal saline solution at the lesion site through the silica pipe sutured to the glefoam once a week after the surgery. All the animals were killed by the end of the third weeks. ④The spinal region of C6,7 level was dissected out for observing survival rate and morphological change of motoneurons of spinal anterior horn as well as the expression of nitricoxide synthase(NOS).MAIN OUTCOME MEASURES: ① Survival and morphological change of spinal motor neurons. ②Change of nitricoxide synthase expression of spinal motor neurons.RESULTS: Totally 20 rats were enrolled in the experiment, and all of them entered the stage of result analysis. ① Survival and morphological changeof spinal motor neurons: 68.6% motoneurons of injured side of the control group died at 3 weeks after surgery. The survival rate was 31.4%,which was significantly lower than that of the intact side (P ＜ 0.01), and the survived neurons was shrinked significantly; the death rate of spinal motor neurons of injured side of experimental group was decreased by 35%as compared with control group (P＞ 0.05). The survival rate was 66.4%,and the survived neuron body was increased, similar to the intact side (P ＞ 0.05). ② Change of nitricoxide synthase expression of spinal motor neurons: In normal spinal cord, NOS positive neurons were shown in dorsal horn, surrounding the central canal and in the intermediolateral column.NOS was not seen in the anterior horn motonurons. At the end of the third week after C6,7 spinal root avulsion, increased NOS expression was not found at the injured side in the Schwann cell derived neurotrophic factor group and the intact side in the control side, while the significantly increased NOS expression of spinal motoneurons was found at the injured side of the control group.CONCLUSION: Degeneration of spinal motoneuron and increased expression of NOS can be induced by spinal root avulsion. SDNF has a significant effect in protecting spinal motoneurons from spinal root avulsion induced cell death and inhibiting the expression of NOS. These results suggest that the effects .of SDNF on motoneuron survival may be achieved by modifying the expression of certain cellular molecule such as NOS.

Objective To screen possible factors affecting prognosis of chondrosarcoma.Methods A total of 37 patients with chondrosarcoma,who had undergone surgical treatment from December 2005 to March 2008 in our hospital and had complete follow-up data and definitive pathological diagnosis,were enrolled in this retrospective study.There were 16 males and 21 females,ageing from eleven to eighty-four years (average,42.8 years).The univariate analysis of survival rate was performed with Kaplan-Meier method and tested with the Log-rank test.Chi-squared test or Fisher's exact test were used to analyze numeration data,and then the significant indexes after univariate analysis were performed multivariate analysis with COX regression model to screen the independent factors affecting prognosis.On the basis of literatures,8factors including gender,age,duration of disease,tumor site,Enneking stage,surgical approach,distant metastasis and local recurrence were analyzed.Results Statistical significance was found in Enneking stage,surgical approach and distant metastasis,which indicated that they were related to survival rate 3years after surgery.However,gender,age,duration of disease,tumor site,and local recurrence had no significant correlation with prognosis.After multivariate analysis of Enneking stage,surgical approach,distant metastasis,the results showed that Enneking stage and surgical procedure were the independent prognostic factors,while distant metastasis was not an independent prognostic factor.Conclusion Enneking stage and surgical approach are the independent prognostic factors for chondrosarcoma,which can be used to evaluate prognosis of chondrosarcoma.

Objective To explore the causes of hepatic perfusion disorders (HPD), and to analysis the CT features of this phenomenon. Methods Nine experimental pigs were randomly divided into three groups. In Group A, B and C, intrahepatic portal, arterial branches and hepatic vein were selectively embolized, respectively. Then all animals underwent contrast enhanced CT scans immediately and after one week. Results On CT images immediately after intervention, HPD were found in all animals. Multiple transient wedge-shaped hyperattenuation represented during the hepatic arterial phase and isoattenuating areas during the portal venous phase. In group A, the site of HPD was in correspondence with the area of embolization,whereas in group B, the embolized area displayed hypoattenuation and non-embolized area displayed hyerattenuation during arterial phase. In group C, the site of HPD was correspondence with the area of embolization in two pigs, but in one pig, the region of HPD was larger than the region of embolization. After one week, HPD disappeared due to sponges absorption and the vessels reopening in group A and B. In group C which hepatic vein was coagulated by laser, HPD remained partially. Conclusion Intrahepatic vascular occlusions of portal, hepatic arterial and hepatic venous branches are the main factors that cause HPD.

Objective To validate the effect of anti-infective reconstituted bone xenograft (ARBX) in treating posttraumatic osteomyelitis by one-stage grafting in the adults.Methods With clinical application approval of Medical Command,Logistics Ministry of PLA,ARBX was used to treat 27 adult patients (29 lesions) with posttraumatic osteomyelitis by one-stage grafting after debridement since September 2001.The study analyzed 27 patients (29 grafts) who were followed up for average 26 months (12-63 months).Results The follow-up for average 26 months (12-63 months) in 27 patients showed that infection of 22 patients (24 lesions) was controlled and cured,except for three with failure to control the infection or with recurrence of infection,two with controlled infection but with postoperative nonunion.The infection control rate was 89.7% (26/29) and the cure rate was 82.8% (24/29) ,which were better than the results of traditional therapy.Conclusions ARBX has high osteoinductive activity and enhanced anti-infective capability,which enables it to be used as one-stage grafting to treat posttraumatic osteomyelitis in the adults.

Objective To assess the therapeutic value of CT guided percutaneous radiofrequency thermal ablation(RFA)for peripheral lung carcinoma(PLC).Methods Forty-three patients with PLC were treated with RFA under the CT guidance.The patients included 26 males and 17 females,and the age ranged from 52 to 76 years.The CT guided percutaneous biopsies were performed to obtain the pathology before the procedures.Results The operations in all cases were successful,little amount of pneumothorax was found in 3 cases,liquid-pneumothorax in 1 case,and large amount of pneumothorax was drainaged in 1 case.The volume of the lesion in 40 cases from 43 patients was diminished gradually at 3 and 6 months follow-up after the procedures.No change in the volume of lesion with peripheral enhancement was seen in 3 cases.Conclusion CT guided percutaneous RFA for PLC is a safe,effective,and minimal invasive procedure.

Objective To discuss the therapeutic efficacy of transcatheter arterial chemoembolization(TACE) via a coaxial microcatheter combined with radiofrequency ablation(RFA) for primary hepatocellular carcinoma(HCC).Methods The preoperative DSA and multi-slice CT findings in 1 000 patients with HCC,encountered from May1998 to May 2007,were retrospectively analyzed.In 179 cases,the lesion was limited in one hepatic segment,and super-selective catheterization TACE with a coaxial microcatheter was performed in these patients.Four weeks after TACE,dynamic enhanced CT and / or MR scanning was made to observe the results.In 40 cases,there was poor lipiodol deposit in the lesion,and CT-guided RFA was employed for these patients.Follow-up check was done one month after the treatment.Results DSA examination totally revealed 670 lesions with diameter larger than 3 cm,202 lesions with diameter smaller than 3 cm,400 satellite nodules,482 arteriovenous fistulae or arterio-portal shunts,430 abnormal blood-supplying vessels and 362 cancerous thrombosis in portal vein.Four weeks after microcatheter embolization,the local control rate of the tumor was 77.6%.RFA was carried out for patients with poorly-controlled tumors,and one month after RFA the local control rate of the tumor reached 97.5%.Conclusions DSA is the most powerful examination means in detecting lesions less than 3 cm,satellite nodules,tumor’s blood-supply,arteriov-enous fistulae and arterio-portal shunts.Therefore,DSA plays an important role in making the preoperative evaluation of HCC,undoubtedly,this role can not be substituted by any other equipment.RFA is an effective treatment for HCC as well as an ideal alternative for patients who show poor response to TACE.

Objective To evaluate the clinical value of CT-guided percutaneous biopsy for bone lesions.Methods Forty-Eight patients with different sited bone lesions had received the procedure of CT-guided percutaneous biopsy from July 2003 to January 2005,including 34 cases only with complete clinical records.The procedure was carried out with patient lied on CT table and followed by localization scanning to demonstrate the best sites for puncture and biopsy route.11-14 G bone puncture needle or 18 G trigger type biopsy needle was undertaken to penetrate into the lesion for obtaining specimens under local anesthesia and CT monitoring and in turn for fixation with 10% formalin to have pathologic examination.Results The whole procedure finished within 20-40 minutes with adequate samples obtained for pathologic examination of all cases.Confirmed diagnosis was made in 30 cases with an accuracy of 91.2% and no correlative complications were found.Conclusions The CT-guided percutaneous biopsy is safe and efficient for diagnosis of bone lesions,deserving to be extensively used.(J Intervent Radiol,2006,15: 603-606)

Objective: To observe the activation of microglia and the changing rule of inflammatory cytokine as IL-6, IL-10 and nuclear factor-κB (NF-κB) in experimental rabbits after spinal cord ischemia reperfusion (SCIR) injury in order to provide theoretical basis for post-conditioning time. Methods: Rabbit SCIR injury model was established by thoracic aorta balloon occlusion. 54 New Zealand male adult white rabbits were divided into 9 groups: Sham group (the animals received balloon implantation without occlusion), SCIR-0h group (reperfusion was conducted at 0 hour of spinal cord ischemia), SCIR-1h, -2h, -3h, -8h, -24h,-48h and -72h groups. n=6 in each group. The number of normal and apoptosis neurons, the levels of Iba-1, IL-6, IL-10 and NF-κB in spinal tissue were examined and compared among different groups respectively. Results: The number of normal neuron was decreasing with the extended reperfusion time, TUNEL-positive neuron began to increasing in SCIR-8h group and the peak was reached in SCIR-24h group. The expression of Iba-1 began to elevating in SCIR-2h group and the peak was obtained in SCIR-8h group; NF-κB began to rising in SCIR-3h group and the peak was observed in SCIR-8h group; both IL-6 and IL-10 arrived the peak in SCIR-24h group. The expressions of NF-κB, IL-6 and IL-10 were positively related to Iba-1 level. Conclusion: Microglia activation had dynamic changes in experimental SCIR rabbits and the expression levels of NF-κB, IL-6 and IL-10 were positively to microglia activation; post-conditioning time at front and back to microglia activation may reduce neuron injury.