Objective: 3D segmentation is an important part of medical image analysis and visualization. It also continues to be large challenge in the medical image segmentation. While level sets have demonstrated a great potential for 3D medical image segmentation, these algorithms have a large computational burden thus are not suitable for real time processing requirement. To solve this problem, we propose a parallel accerelated method based on CUDA. Methods: We implement C-V level set algorithm in the CUDA environment which is the NVIDIA's GPGPU model.The segmentation speed can greatly improved by using independence of image pixel and concurrence of partial differential equation .The paper shows the flow chart of the parallel computing and gives the detailed introduction of the C-V level set algorithm which is implemented in the CUDA environment. Results: Realizing the C-V level set parallel accerelated algorithm. This method has faster segmentation speed while preserving the qualitative results, Conclusions: This method is viable and makes the fast 3D medical image segmentation come hue.

Objective: Real time medical image registration technique is one of the key techniques in image based surgery navi-gation system. While in medical image analysis, image registration is usually a very time-cousuming operation, and this is not conducive to clinical real-time requirements. This paper studies and realizes the acceleration of the process of image registra-tion. Methods: In order to improve the regisWation rate, in this paper, we propose a new technology which is based on CUDA (Compute Unified Device Architecture) programming model to accelerate the process of registration in hardware, using paral-lel methods to achieve pixel coordinate transformation, linear interpolation, and calculate the corresponding pixel gray value residuals. Results: The registration is up to the sub-pixel level and the GPU-based registration is dozens or even hundreds of times faster than CPU-based registration. Conclusions: This method greatly enhances the speed of rigid registration without changing the alignment accuracy.

Objective To determine whether arsenic has estrogen-like effects,the cell proliferation was measured iil human eervical cancer line(HeLa)in vitro.Methods The HeLa cells were grown in improved RPMI 1640 supplemented respectively with β-estradiol(E2,1 nmol/L),Arsenic trioxide(As2O3,0.5,1.0,5.0 μmol/L),ICI (500 nmol/L),E2(1 nmol/L)+ICI(500 nmol/L),As2O3(1.0 μmol/L)+ICI(500 nmol/L)and control.The growth morphology of HeLa cell was observed under microscope after 72 h.The method of M1Tr was used to study the cell proliferation after 24.48 and 72 h.The technique of flow eytometry was used to measure cell cycle after 48 h. Results HeLa cells in E2 and 0.5 μmoL/L As2O3 treatment were more better growth in morphology than control group.Percentage of HeLa cells proliferation at 24,48,72 h in E2 and 0.5 μmol/L As2O3 treatment were 6.35%, 11.56%,38.33%and 6.35%,8.50%,20.26%respectively.The proliferation effect of HeLa cells was similar in two treatments.The proliferation of HeLa cells were inhibited in other treatments.Compared with control[(41.68± 1.05)%],HeLa cells were promoted go to S phases in E2[(55.72±2.31)%]and 0.5 μmol/L As2O3[(47.82± 1.41)%]treatment.But in other treatments HeLa cells were hold back to S phases.Compared with control,there was a significant differenee(P＜0.05)of cell percentage in S phases in 5.0 μmol/L As2O3[(21.11±4.99)%]and ICI[(20.16±4.76)%]treatments.Conclusion Small amounts of As2O3 impose estrogen.1ike effects and stimulate the proliferation of HeLa cells.

BACKGROUND:Acellular dermal matrix possesses good flexibility and simple trimming.The intracutaneous or subcutaneous injection of acellular dermal matrix powder has fibroblast migration and collagen deposition.It has been widely used in plastic and reconstructive surgery.OBJECTIVE:To explore the feasibility of reconstructed acellular dermal matrix as a scaffold for chondrocyte implantation.DESIGN,TIME AND SETTING:Comparative observation.The study was performed at the Peking University Medical Department and Beijing Jishuitan Hospital between August 2003 and February 2007.MATERIALS:Neonatal calf dermis was provided by Beijing Yuanheng Shengma Biology Technology Research Institute.A total of 24 healthy adult SD rats,weighing 250 g,regardless of gender,and 36 New Zealand rabbits,aged 3 months,were selected.METHODS:①Calf full-thickness back skin was incubated with cell free buffer or ABS/AES for decellularization,followed by surface modification using growth factors.②Three rectangle skin flaps at two sides of the spinal cord of rats were made,and implanted with acellular dermal matrix.The implants were harvested at 2,6,and 12 weeks postoperatively.③The rabbits were divided into experimental and control groups.The cartilage was obtained from the left articular facet to isolate chondrocytes.The chondrocytes were seeded on the acellular dermal matrix.The cartilage defect was made on the right hind limb of experimentalrabbits,and implanted with acellular dermal matrix containing autoiogous chondrocytes.Biogel wass dropped on the surface of carrier.In the control group,the cartilage defect was made on the right hind limb of rabbits and the wound was sutured.Two rabbits from control group and 5 from experimental group were selected respectively at 4,12 and 24 weeks postoperatively.MAIN OUTCOME MEASURES:Cross-linking effect comparison;repair effect of rabbit bone defects.RESULTS:①The acellular dermal matrix cross-linked by glutaraldehyde demonstrated an obvious inflammatory reaction with tissue bleeding and necrosis.Conversely,ADM treated with water-soluble cross-linking agent caused displayed good histocompatibility.②The cartilage defects were repaired completely;the attached cells survived and proliferated and the acellular dermal matrix was degraded after 24 weeks of surgery.CONCLUSION:The acellular dermal matrix decellularized with cell free buffer,digested with digestive buffer,Cross-linked by water-soluble cross-linking agent,and further decorated with growth factor exhibited good histocompatibility,and was suitable forcell attachment and growth.The acellular dermal matrix scaffold almost degrades in the rabbits,with no rejection,and the bone defects were repaired after 24 weeks.

Course teaching for international students in many domestic universities is in English.Some practice and experience of the department of nuclear medicine in Tianjin medical university are introduced from the aspects of teaching course,concerning preparations before class,teaching process and teaching techniques,which will give references to nuclear medicine teaching for international students.

Objective To synthesize the hydrophobic supraparamagnetic ironic oxide(SPIO) loaded and hydrophilic SPIO loaded polymeric nano-vesicles and to investigate the feasibility of using hydrophobic SPIO loaded and hydrophilic SPIO loaded polymeric nano-vesicles to display the tumor in MRI in vivo through animal experiments. Methods The polymeric nano-vesicles were prepared from poly (D, L-lactic acid) (PDLLA) and poly (ethylene glycol) (PEG) by a multiple emulsion/solvent evaporation method.The hydrophobic SPIO and hydrophilic SPIO were loaded in the polymeric nano-vesicles respectively.Eighteen nude mice models with human colorectal carcinoma xenograft were established. They were divided equally into three groups (n = 6). The three groups of nude mice models were injected with water-soluble SPIO, hydrophobic SPIO loaded and hydrophilic SPIO loaded vesicle via the mice caudal vein respectively.Dynamic MRI scan were performed in all the mice models. T2WI signal intensity and T2 relaxation time were measured in the tumor, liver and muscle by using T2 mapping software. ANOVA of repeated measurement was used to analyze if there were significant differences of signal intensity changes among the three groups, while Bonferroni method was used for pair-wise comparison. Results On T2 WI, tumors showed decrease in signal intensity after hydrophobic or hydrophilic SPIO loaded polymeric nano-vesicle injection, while no signal intensity decrease was found in the tumor after water-soluble SPIO administration. The maximum percentage of signal intensity decrease in tumor caused by hydrophobic SPIO loaded and hydrophilic SPIO loaded vesicle were 11.00%, 11.40%, respectively. There was statistical significant difference of signal intensity changes among these three groups (F = 10. 96, P ＜ 0. 01). The decrease in signal intensity in the groups with hydrophilic or hydrophobic SPIO loaded polymeric nano-vesicles injection were more pronounced as compared with that of water-soluble SPIO (P ＜ 0. 05), but there was no significant difference in signal intensity decrease between the groups of hydrophilic and hydrophobic SPIO-loaded polymeric vesicles injection (P ＞0. 05). The three agents could lead to signal intensity decrease in the liver. The maximum percentage of signal intensity decrease in liver caused by water-soluble SPIO, hydrophobic SPIO loaded and hydrophilic SPIO loaded vesicle were 32. 85%, 52. 77%, 56. 89%, respectively. There was statistical significant difference between these groups (F = 161.18, P ＜ 0. 01) . The groups of injecting hydrophilic and hydrophobic SPIO loaded polymeric nano-vesicles had the more obvious signal decrease than the one with water-soluble SPIO (P ＜ 0. 01). Hydrophilic SPIO loaded polymeric nano-vesicles exhibited more signal intensity decrease than hydrophobic SPIO loaded polymeric nano-vesicles (P ＜ 0. 01). All three agents could not lead to T2WI signal decrease in the muscle, and there was no significant difference in signal change on T2 WI among three groups (F = 0. 59, P ＞ 0. 05). Conclusion SPIO loaded polymeric nano-vesicles can cause significant T2WI signal loss in human colonic carcinoma on MR imaging in vivo. It can be used as tumor imaging contrast agents.

Objectives:To study efficiency characteristics and changes of county hospitals based on data envel-opment analysis model from 2008 to 2012 . Methods:A three-stage DEA model which can exclude the external envi-ronment variable on its efficiency is also added along with the C2 R and BC2-DEA traditional model. Results: From 2008 to 2012, the technical efficiency value was ranging between 0. 723 and 0. 681 in county hospitals, the pure technical efficiency was 0 . 785~0 . 771 and the scale efficiency value scaled between 0 . 908 and 0 . 897 . These values showed a low efficiency, but had annually improved. This reflects that the new health care reform policies have played an important role in improving county hospitals efficiency. Development of medical service ability is behind the development of hospital scale. How to improve the service and management capabilities has gradually become a major direction to improve the county hospital efficiency.

Objective To investigate the function of soluble stem cell factor receptor(s-kit)and stem cell factor(SCF) in chronic aplastic anemia(CAA).Methods ELISA assay was employed to determine the levels of s-kit and SCF in peripheral blood of CAA patients and umbilical cord blood.Results The levels of s-kit and SCF in peripheral blood of CAA patients are lower than those of normal group and umbilical cord blood group.Conclusions The decreased levels of s-kit and SCF show that s-kit and SCF may play a role in CAA mechanism.The raised levels of s-kit and SCF show that s-kit and SCF may be applied in the field of cord blood transplantation.

Objective To observe dopamine transporter (DAT) binding capacity using 99Tcm-TRODAT-1 in drug-naive patients with Tourette's syndrome (TS) on SPECT imaging, and explore possible correlations between 99Tcm-TRODAT-1 uptake ratio and TS patient's age, disease duration, and tic severity.Methods Eighteen drug-naive TS patients, male 14, female 4, as well as 8 age- and gender-matched healthy subjects were recruited. Brain SPECT imaging was performed 2. 5 h after intravenous injection of 11.1 - 14.8 MBq/kg 99Tcm-TRODAT-1. ROI was drawn on the striatum including its sub-regions of caudate and putamen, with cerebellum as the background. Striatum/cerebellum ratio was calculated. Comparisons of the ratios between TS patients and controls were carried out by independent-sample t-test. Pearson correlation analysis was performed between DAT uptake ratios of striatum and patients' age, disease duration, tic severity. Results Compared with the control, higher symmetrically striatum uptake of 99Tcm-TRODAT-1 in TS patients was observed (2.17±0.23 vs 1.87±0.24, t =2.957, P＜0.05). Age (r= -0.320, P＞0.05)and tic severity(r = 0. 345, P ＞ 0.05) scores were not significantly correlated with specific uptake ratios measured in the striatum. But there was significant negative correlation between disease duration and the specific uptake ratios (r = - 0. 483, P ＜ 0. 05). Conclusions 99 Tcm-TRODAT-1 SPECT imaging may play an adjuvant role for initial evaluation of untreated TS.

Objective To investigate the effect of video -assisted thoracoscopic surgery (VATS)and conventional thoracotomy in treatment of thoracic esophagus cancer,to provide the reference for clinical.Methods 90 cases of thoracic esophageal cancer in our hospital from January 2012 to January 2015 were chosen as the research subjects.They were randomly divided into observation group(application of VATS treatment)and the control group (application of traditional open chest surgery).The quantity difference,chest drainage,hospitalization time,complica-tions,recovery conditions and other indicators of bleeding were compared in the two groups.Results The operation time of the observation group[(267.6 ±76.5)min]was shorter than that of the control group[(324.4 ±87.6)min]. The amount of intraoperative bleeding[(235.3 ±79.5)mL],drainage volume[(327.5 ±95.2)mL]of the observation group were less than the control group[(398.2 ±98.3)mL and (752.6 ±156.4)mL].Postoperative hospitalization time[(12.2 ±3.2)d]of the observation group was shorter than the control group[(15.8 ±4.4)d].The differences were statistically significant (t =3.276,8.644,15.575,4.439,all P <0.05).There were no significant differences between two groups in recurrence and metastasis rate,mortality rate and total survival rate (χ2 =0.123,0.212, 0.212,all P >0.05).The complication rate of the observation group was lower than that of the control group,the difference was statistically significant (χ2 =4.865,P <0.05).Conclusion In the treatment of thoracic esophageal carcinoma,VATS and conventional thoracotomy surgery has good effect,and VATS has small injury,less complication.