Objective To simulate the hemodynamic feature in cerebral bridging veins (BVs), in order to provide a morphologic basis for the pathogenesis explanation and imaging diagnosis of cerebral venous thrombosis (CVT). MethodsTotally 6 human cadavers (12 sides) were examined in this study. Each head of the cadavers was injected with blue-coloured latex via the superior sagittal sinus (SSS) and internal jugular veins. The diamter and the angle of BVs entering SSS were measured. Based on the data of cadavers and computational fluid dynamics software pack, the hemodynamic models were established. The wall shear stress (WSS) was carefully studied and compared between different models. Results The total of 137 BVs formed two clusters along the SSS: anterior group and posterior group. Compared with anterior group BVs, the diameter of posterior group BVs was large, and the angle was smaller. In 137 models,when the diameter of a BV was more than 1.2mm, and the angle was between 65 and 105 degree, the local WSS decreased in the downstream wall of SSS. When the diameter of a BV was more than 1.2mm, and the angle was less than 65 degree, the local WSS decreased in the downstream wall of SSS and the upstream wall of BVs. The minimum WSS in BVs was 63% of the minimum WSS in SSS. Compared with the anterior group BVs, the minimum WSS in the wall of posterior group BVs was samller, and the distance from the minimum WSS to the dural entrance was longer. Conclusion CVT occurs easily when the diamter of a BV is more than 1.2mm and the angle is less than 65 degree. The embolus forms early in the upstream wall of BVs entering the posterior part of SSS.

BACKGROUND:A large number of literatures have shown that surgeons expose to a higher radiation dose during puncture and bone cement injection in percutaneous vertebral augmentation. OBJECTIVE:To review the research progress in radiation doses and safeguard procedures in percutaneous vertebral augmentation. METHODS: By using percutaneous vertebral augmentation, radiation doses, radiation protective as key words, we retrieved articles related to radiological protection during percutaneous vertebral augmentation published from January 1995 to December 2014 in Wangfang database and PubMed database. RESULTS AND CONCLUSION:One basic principle of radiation protection is that the radiation dose decreases rapidly with distance from the radioactive sources. Surgeons should maximize the distance from the radioactive sources as far as possible in case there is no effect on the operation. To optimize the setting and position of C-arm machine, wear protective devices and put lead shields as wel as computer navigation and radiation training in surgeons al can help to reduce the radiation doses during percutaneous vertebral augmentation. Remote bone cement injection device is easy to control but not increases the radiation doses. In addition, the influence of surgery bed on radiation dose remains to be further studied. We believe that with the in-depth research on radiological protection, vertebral augmentation technique wil be safer in clinical application.

Objective To learn the overall results of the final test paper in nursing undergraduates of Peking Union Medical College, and to provide the theoretical support for teaching quality assessment of nursing undergraduates.Methods The difficulty coefficient, the discrimination index, the reliability (Cronbach α coefficient) and the degree of coverage were analyzed based on education measurement and education statistical methods.Results The mean total score was 67.8±12.5, ranged from 38 to 95.The difficulty coefficient, the discrimination index and the Cronbach α coefficient were 0.68, 0.30 and 0.71 respectively.The rates of loss score were 33.8% for choice questions, 37.2% for completion questions, 22.5%for true or false questions and 24.8% for calculation questions respectively.Among the total 30 examination questions, the proportions of the most difficult ones, the difficult ones, the moderate ones, the easy ones and the easiest ones were 30.0%,13.3%,20.0%,20.0% and 16.7% respectively.28 examination questions (93.3%) had the best or better discrimination.Conclusions The test paper held the moderate difficulty and the good discrimination, reliability and the degree of coverage.The results of the examination accurately reflect the knowledge and ability of the students.In addition, more attention should be paidto improve the knowledge of nursing undergraduates on the importance of the medical statistics in medical scientific research.

10.3969/j.issn.2095-4344.2013.25.008

OBJECTIVETo investigate the value of MRI follow-up in pediatric patients with spinal tuberculosis.

METHODSFrom February 2004 to April 2013, MRI imaging data in 21 children with spinal tuberculosis by pathologically and clinically proven were retrospectively analysed. There were 11 males and 10 males, with an average age of 9.4 years old ranging from 2 to 14 years old. Eighteen patients were received conservative treatment, 3 patients were treated by surgical operation. The course of disease ranged from 2 months to 3 years. All cases underwent two or more MRI examinations for follow-up. MRI findings of the first and second examination were comparatively analyzed,including signal changes of vertebral body and intervertebral, paraspinal abscess and the change of kyphosis angle.

RESULTSIn the 21 cases with tuberculosis, 85 vertebral bodies were affected in total, including 10.6%(9/85), 49.4%(42/85) and 40%(34/85) vertebral bodies separately in the cervical,thoracic, lumbosacral spine. Follow-up MRI showed vertebral body shape and signal had no obvious change during or after treatment, 15 cases with vertebral bodies changed flat or cuneate, 10 cases with disc involvement,and intervertebral space became narrowing at different level. Among 13 patients with kyphosis angle greater than 0°, 7 were located on thoracic, 2, 3, 1 were on thoracolumbar, lumbar and cervical spine, respectively. Among 18 cases with conservative treatment,kyphosis angle were 0° on the first and the follow up MRI of 8 patients. One case of mild (<10°) kyphosis,follow-up MRI during therapy showed the angle slightly increased; 5 cases with moderate (10° to 30°), follow-up MRI during therapy showed no obvious change; 4 cases with severe (>30°), follow-up MRI during and after therapy showed kyphosis increased in varying degrees.

CONCLUSIONFollow-up MRI can make a big difference in the spinal tuberculosis of children; it can clearly show the change of the vertebral body and intervertebral space, paraspinal abscess and the kyphosis angle after the treatment,which can provide reference for clinical treatment and estimating prognosis.

Adolescent ; Anti-Bacterial Agents ; therapeutic use ; Child ; Child, Preschool ; Drug Monitoring ; Female ; Follow-Up Studies ; Humans ; Magnetic Resonance Imaging ; Male ; Radiography ; Retrospective Studies ; Spine ; diagnostic imaging ; Tuberculosis, Spinal ; diagnostic imaging ; drug therapy ; surgery

The study aims to characterize and compare interferon reference standards from 5 manufacturers. By testing molecular mass and trypsin-digested peptide mass mapping, the amino acid sequence was verified and post-translational modifications such as disulfide bond were identified. Results show that the molecular mass and amino acid sequence were consistent with theory; the disulfide bonds of 4 lots of interferon were Cys1-Cys98/Cys29-Cys138, 1 lot was Cys29-Cys139/Cys86-Cys99; N-terminal "+Met", acetyl N-terminal and Met oxidation were identified in part of the sample. UPLC-MS can be used to characterize and compare interferon reference standards from different manufacturers.
Amino Acid Sequence ; Chromatography, High Pressure Liquid ; methods ; Interferons ; standards ; Mass Spectrometry ; methods ; Molecular Weight ; Oxidation-Reduction ; Peptide Mapping ; Protein Processing, Post-Translational ; Reference Standards

Objective: To acquire recombinant nematode anticoagulant peptide ( NAP) with high anticoagulant activity. Methods: Pichia pastoris GS115 strain was transformed with recombinant yeast expression vector pPICS. 5K-rNAP. Expression of rNAP was induced with methanol after the identification of positive strains. NAP expressed in the collected yeast culture supernatant was confirmed with SDS-PAGE and Western blot. The biological activity of the products was validated with PT (prothrombin time) , INR (international normalized ratio) and APTT (activated partial thromboplastin time) , respectively. Results: The yeast strains expressing NAP were identified. The rNAP was secreted into culture supernatant with a molecular weight of about 10 kDa due to glycosylation, which is a little bigger than that predicted (8.7kDa). The anticoagulant efficiency of rNAP was confirmed with the in vitro assays. Conclusion: The recombinant nematode anticoagulant peptide with high biological activity was successfully expressed in Pichia pastoris and can be used in the future development of novel anticoagulant agent.

Objective To explore the toxicity and biological activity of cobalt nanoparticles (CoNPs) on osteoclasts,and to analyze the relationship between cobalt nanoparticles and osteolysis.Methods From November 2014 to July 2015,RAW264.7 cell was induced to osteoclast-like cell by LPS.Different concentrations of cobalt nanoparticles and cobalt chloride were added,and the cell morphology was observed under a microscope.24 h after induction on RAW264.7,cells were grouped into cobalt nanoparticles group (10,20,50,100 μmol/L),cobalt chloride group (10,20,50,100 mol/L) and control group.MTT assessment and Q-PCR were performed at 2 h,4 h,8 h,24 h,48 h post-treatment.Results With the increase of concentration (10,20,50,100 μmol/L) and the action time (2 h,4 h,8 h,24 h,48 h),the inhibition rate of cobalt nanoparticles and cobalt chloride on osteoclast like cells was significantly increased,and the inhibition rate of cobalt nanoparticles was higher.With different concentrations (10,20,50,100 μmol/L) of CoNPs and cobalt chloride,the relative expression of CAⅡ,Cat K gene mRNA expression decreased compared with the control group,when the concentration of CoNPs was in the range of 10-50 μ mol/L,the relative expression of CAⅡ and Cat K was increased,which was reduced in cobalt chloride group.Conclusion Different concentrations of cobalt nanoparticles and cobalt chloride can inhibit the proliferation and differentiation of osteoclasts,and cobalt nanoparticles is more pronounced,when the concentration of cobalt nanoparticles was 10-50 μmol/L,the relative expression of osteoclasts CAⅡ,Cat K increaseed,which was suppressed at the same concentration of cobalt chloride.

Objective To assess the variations in different thyroid stimulating hormone(TSH) and free thyroxine (FT4) detection kits for evaluating thyroid function during pregnancy and to establish the corresponding normal reference ranges.Methods This study was based at the International Peace Maternity and Child Health Hospital affiliated to Shanghai Jiaotong University School of Medicine.A total of 200 pregnant women who visited the hospital between June,2011 and September,2012 were recruited in this study according to the National Academy of Clinical Biochemistry (NACB) criteria.Blood samples were sequentially collected from the women at the first (T1,9-12 weeks),second (T2,16-24 weeks) and third (T3,32-36 weeks) trimesters to determine the serum TSH and FT4 levels using four different detection kits (Siemens-C,Siemens-Ⅰ,Abott and Roche).A linear trend test was used to analyze serum TSH and FT4 levels with four different kits.A percentile range of P2.5 to P97.5 was used to establish the normal trimester-dependent reference ranges of TSH and FT4 levels for different detection kits.The Bootstrap method was used to compare the differences in the four reference ranges.Results Similar dynamic changes in TSH and FT4 levels during pregnancy were detected among the different kits (F=0.950,P=0.595; F=11.640,P=0.081,respectively).Among the four reference ranges of TSH,the Roche kit showed the most remarkable fluctuation during pregnancy,while Roche kit in the first trimester and Siemens C kit in the second and third trimesters showed larger fluctuations in reference ranges of FT4.More importantly,the reference ranges of TSH and FT4 showed significant variations among the four different kits in each trimester (TSH:T1:F=2 945.390,P ＜ 0.01; T2:F=2 826.260,P ＜ 0.01; T3:F=1 698.360,P ＜ 0.01.FT4:Tl:F=1 145.440,P ＜ 0.01; T2:F=2 260.240,P ＜ 0.01; T3:F=1 439.920,P ＜ 0.01).Conclusions TSH and FT4 measurement using four different commercial kits showed similar trimester-dependent dynamic changes.However,it is necessary to establish trimester-dependent and detection kit dependent normal reference ranges of TSH and FT4 for thyroid function evaluation for pregnant women.

Objective To establish the sulfur mustard (SM ) induced tracheal injury model in rat and to investigate its mecha-nism .Methods Male rats (SD) were anesthetized and intra-tracheally intubated .The SM group was intra-tracheally injected by 2 mg/kg of diluted SM ,while the propylene glycol control group only by 0 .1mL of propylene glycol and the normal control group had no any treatment .The tissue and blood samples were taken for conducting the HE and immunohistochemical staining and measuring serum enzymes and andinflammatory factors .Results In the SM group ,a large number of lymphocytes infiltration in submucosa were observed;the positive expression of caspase-3 and caspase-9 were observed in epithelium and submucosa ;serum levels of TNF-α,IL-1β,IL-6 reached the peak in 24 h;serum levels of LDH ,GP ,BARS reached the peak in 6h ,so did GGT in 24 h .In the propyl-ene glycol control group and the normal control group ,lymphocytes ,macrophages and neutrophils were rare in submucosa .Conclu-sion The mechanism of SM (2 mg/kg) induced acute tracheal injury involves the inflammatory reaction ,apoptosis and oxidative stress ,moreover the lesion degree has the correlation with time .