Objective:This study was based on digital orthodontic diagnosis work flow for indirect bonding transfer tray model design and three-dimensional (3D) printing, and the aim of this paper was to inspect the dimensional accuracyof 3D printed brackets, which is the foundation of the follow up work and hoped that will illuminate the clinical application of the digital orthodontics work flow.Methods: The samples which consisted of 14 cases of patients with malocclusion from Department of Orthodontics Peking University were selected, including 8 cases with tooth extraction and 6 cases without tooth extraction.All the 14 patients were taken intra-oral scan (Trios 3Shape,Denmark)and cone-beam computed tomography (CBCT, NewTom 3G volumetric scanner, Aperio Service,Italy)shooting after periodontal treatment.STL data and DICOM data were obtained from intraoral scans and CBCT images.Data segmentation, registration, fusion, automatic tooth arrangement, virtual positioning of orthodontic appliance and conversion the coordinates of malocclusion model were all done with self-programming software.The data of 3D printing model with brackets on it were output finally and printed out with EDEN260V (Objet Geometries, Israel) to make indirect bonding transfer tray.Digital vernier caliper was used to measure the length and width of upper and lower left brackets and buccal tubes on those 3D models after removal of surrounding supporting material by ultrasonic vibration and water-spray.Intra-examiner reliability was assessed by using intra-class correlation coefficients (ICC), and one-sample T test was used to compare the measurements with the standard dimensional data of the brackets.Results: There were significant differences which range in 0.04-0.17 mm between the 13 items out of the 19 measurement items.Except for the length of the lower left premolars''brackets, mean values of the other items were greater than the test value.Conclusion: Although the measurement results in the width of brackets and the width and length of the buccal tubes obtained experimentally were slightly larger than the test value,this may not reduce the accuracy of indirect bonding procedure in clinic necessarily.Whether the differences which range in 0.04-0.17 mm would actually affect the retention and positioning of brackets needs to be confirmed by further studies.

Objective To improve the CT diagnostic rate of malignant ovarian tumor(MOT).Methods The CT appearences of 42 cases with MOT confirmed by operation and pathology were analyzed retropectively.The CT findings and types,differential diagnosis were emphatically discussed.Results (1)Ovanian tumors were most frequently located in the adnexal and the pouch of Douglas(78.6%);(2)The size of tumors was mostly beyond 5 cm in diameter(95.2%);(3)The most of tumors apperared flower-shaped(71.4%);(4)The tumors were classified as cystic,cyst-solid and solid types,but cyst-solid type was common(61.9%);(5)The solid and solid portion of the mass were enhanced obviously(90.8%);(6)Ascites and invasion of the adjacent organs were common appearences of the metastasis;(7)Arched,small nodelar and nodular calcification in a solid mass or solid portion of mass could be found.Conclusion CT examination is of great value in diagnosis of MOT,which may predict the pathologic characteristics of MOT.

Purpose To investigate the features and diagnostic value of multi-slice spiral CT (MSCT) in eosinophilic gastroenteritis (EG).Materials and Methods The clinical and imaging data of 12 EG patients confirmed by gastrointestinal endoscope and pathological biopsy were analyzed retrospectively.The MSCT features were summarized according to the clinical classification,the location and depth of the invasion.Results Seven of twelve EG cases were mucosa type.Among them,CT of five cases with stomach involvement showed thickening and edema of the gastric wall and submucosal pseudopolyp nodules nodular shadow.Two cases with intestinal involvement showed thickening of'feather like'jejunal duplicature and saw-toothed change.Muscle type was rare and only one case in ileocecus.Thickening and stiffness of the bowel wall with intestinal stenosis and mass like change was observed.One case of serous type with coarse serosal surface,straight small vascular thickening,perienteric fiber fat thickening and small amount of ascites.Three cases of mixed type were found single invasion or multiple invasion and jumped-type development of multiple intestinal tract.Feathers of the intestinal wall stratification and multiple ring enhancement suggested that mucosal and submucosal lesions coexist with serosal lesions.Conclusion Each type of EG has its characteristic MSCT manifestation that provides objective imaging diagnosis and typing basis for the clinical diagnosis of the disease when combined with peripheral blood eosinophilia.Clinical treatment can be based on the classification and the range of involvement of EG,which is of great significance for follow-up evaluation.

Objective To clone and characterize Profilin encoding genes in Amaranthus spinosus and to analyze the contribution of different amino acids in isoallergens to allergen antigenicity and tertiary structure. Methods The primers were designed according to the core sequences which were obtained by bioinformatic analysis of the known Profilin amino acid sequences, followed by gene cloning from the Ama- ranthus spinosus cDNA pool and subsequent confirmation by double-digestion, colony PCR and DNA sequen- cing. Antigenicity evaluation and tertiary structural modeling of the encoded protein were accomplished by online software MULTIPRED and SWISS-MODEL, respectively. Results Two panallergenic genes, named as PRF7 and PRF23, were acquired from Amaranthus spinosus. Sequence and structure analysis demonstra- ted that there was some discrepancy in tertiary structures of the encoded proteins, besides distinct difference in their amino acid sequences. PRF7 exhibited high homology with panallergen Profilins Q64LH0, with the identities 98%, whereas the homology of PRF23 and Q9XF42 (apple allergen) was 81%. Q64LH0 and PRF23 were modeled as 3nulA (Q42449) and lg5uB (Q9LE18), respectively. PRF23 exhibited distinct0 three dimensional structural difference in certain fragments compared with Q64LH0 and other Profilins. Though the average values of antigenicity displayed no difference between Q64LH0 and PRF23 on whole se- quences, the antigenicity of PRF23 on certain fragments was obviously lower than that of Q64LHO because of the alteration of some amino acids with different characters, implying the cause of lower incidence of hay fe- ver in South China than in North China. Conclusion Based on sequence analysis, antigenicity evaluation and tertiary structural modeling for Q64LH0 and PRF23, we obtained lots of useful information about the contribution of different amino acids to antigenicity and protein structures, thus would facilitate allergen ge- netic improvement by amino acid replacement.

Objective To introduce the experience of improved posterolateral mini-incision total hip urthroplasty(THA)in treatment of femoral neck fractures.Methods Of 199 patients(207 hips)treated with preliminary THA from October2002 to January 2005,them were46 patients(46 hips)with femoral neck fractures including31 fresh fractures and 15 old ones,which were then treated with posterolateral mini-incision THA.An observation was done on length of incision,operation time,volume of blood loss,drainage volume,hospital stays,postoperative complications,functional recovery and Harris score.Results All patients were followed up for 14-26 months(mean 17.2 months).The final Harris score during follow-up was(84.1±8.6)points in the fresh fracture group and(85.8±7.6)points in the old fracture group.Pestoperative X-ray showed sound position of the prosthesis.There was no statistical difference upon length of incision,operation time,blood loss,drainage volume and hospital stays between fresh fracture group and old fracture group(P＞0.05).Dislocation occurred in one patient in each group.Conclusion Posterolateral mini-incision THA is proved to be successful in reducing surgical trauma,accelerating rehabilitation and decreasing blood loss and complications for patients with femoral neck fractures.

Objective To screen strains of minipigs sensitive to highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) for evaluation of HP-PRRS live vaccine.Methods Lantang pigs, Juema, Bama and Wuzhishan ( white) minipigs were inoculated with virulent strain NVDC-JXA1 of PRRSV, and local binary hybrid pigs were used as control.The animals were continuously observed for 5 weeks on mental status, appetite, survival, etc.after inoculation of virus.The dead pigs were autopsied and the lung tissue samples were collected for detecting virus by RT-PCR.By the end of the experiment, serum of survival animals were collected for detecting PRRSV antibody by ELISA assay.Result The animals showed depression, anorexia, and other clinical signs and death in each group after inoculation.Meanwhile, the testing results were all positive in the RT-PCR and ELISA detection.Bama and Wuzhishan ( white) minipigs were the most sensitive to virulent strain NVDC-JXA1 of PRRSV regarding mortality rate.Conclusions Bama and Wuzhishan ( white) minipigs are sensitive to HP-PRRSV, and can be used for the inspection of HP-PRRS live vaccine.