Passive mechanical behaviors of mammal extraocular muscles: a comparison among fox,pig and sheep / 中国组织工程研究

BACKGROUND:The extraocular muscles control the movement of the eyeball,and its biomechanics is essential for studying eye movement.OBJECTIVE:To determine the differences in mechanical properties of the extraocular muscles in different mammals.METHODS:This was an in vitro study.The extraocular muscles were extracted from foxes,pigs and sheep,and then we used an Instron 5544 tester to perform uniaxial experiments under the same load.Ogden hyperelastic models of each animal extraocular muscle were obtained based on the experimental data,and the passive mechanical behaviors of the extraocular muscle were compared statistically among different animals.RESULTS AND CONCLUSION:The order of load-strain values was as follows:fox ＞ sheep ＞ pig.The fitted curve of each animal extraocular muscle was well in accordance with the mean data.There were significant differences in the passive mechanical behaviors of extraocular muscles among mammals,including hyperelastic parameters and stress response at the same load level.

Influence of Width and Thickness of DCI's Curved Section on Its Performance / 中国医疗器械杂志

By establishing a series of Dynamic Cervical Implants (DCI) within C5-C6 cervical spinal segments, the biomechanical finite element analysis for DCI with different width and thickness were carried out to investigate the influence of the width and thickness of DCI's curved section on its equivalent stress and range of motion (ROM), so as to provide some theoretical basis for the optimization of DCI's design. The results show that the width of DCI's curved section has more obvious influence on the ROM of lateral bending and torsion, in comparison with the thickness of DCI's curved section. By appropriate reduction in width, the ROMs of lateral bending and torsion increase obviously, i.e. the overall movement function of patients is improved. Furthermore, the increase of equivalent stress could be counteracted by corresponding increase of thickness.

Establishment and preliminary application of the McA-RH7777/Buffalo hepatoma rat model with bioluminescence imaging / 中华肝胆外科杂志

Objective To establish a luciferase labeled McA-RH7777 hepatoma rat model,which could be used for gross observation to further observe the effect of selective ligation of the portal vein and bile duct on tumor growth and metastasis.Methods The luciferase gene was transfected into rat McA-RH7777 hepatoma cells with pCDH-puromycin-CMV as the carrier,which were subcutaneously inoculated into Buffalo rats.Tumor pieces were then heterotransplanted into the left lateral lobe of the allogenic rat liver to observe the tumor growth in vivo.After the successful hepatoma modeling,the rats were randomly divided into three groups,namely the implanted portal vein group with combined portal vein and bile duct ligation,the implanted portal vein group with single portal vein ligation and sham operation group.The rats were executed at the 1 st week and 2nd week after ligation,and the livers were dissected to record the tumor growth and metastasis inside and outside the liver,respectively.Results The tumor formation rates of Buffalo rats after subcutaneous and intrahepatic implantation were both 100％.The fluorescence signal implanted into the liver lobe could be observed in vivo after the intrahepatic implantation of luciferase transfected Luc-McA-RH7777 at 2nd week,the range and intensity of which increased over time.Only local tumor growth could be found at the 4th week,without obvious intrahepatic and lung metastasis.However,both an increased in situ tumor volume and the pulmonary metastasis could be observed in the implanted portal vein group with combined portal vein and bile duct ligation at 2nd week after the ligation.Immunohistochemistry showed AFP positive immunoreactions in the vast majority of intrahepatic tumor cells and Luc positive immunoreactions in part of tumor cells.Conclusion Luc-McA-RH7777 cells could be used to establish the heptoma rat model and the in vivo analysis within the Buffalo rat liver demonstrated that the combined ligation of the portal vein and bile duct can accelerate the development and metastasis of liver cancer.

Suppression of NAMPT expression enhances the sensitivity of K562 cells to imatinib and its relative mechanism / 中国实验血液学杂志

The aim of this study was to investigate the effect of suppression of nicotinamide phosphoribosyltransferase (NAMPT) expression on imatinib-sensitivity in chronic myelogenous leukemia (CML) cell line K562 and its mechanisms, NAMPT siRNA was synthesized and transfected into K562 cells. PI/Calcein staining technique was used to determine survival rate of transfected K562 cells at 48th hour after exposure to 1 µmol/L imatinib. MTS method was used to determine the proliferation changes of transfected K562 cell at 48th hour after exposure to different doses of imatinib, then half inhibitory concentration (IC(50)) was calculated. Expression of NAMPT at 3rd-48th hour after exposure to 1 µmol/L imatinib was determined by Western blot. To explore the effect of NAMPT-siRNA and imatinib on the expression of apoptosis-related genes, the microarray data from NCBI GEO Data-Sets was analyzed, then the results were confirmed by Western blot. The luciferase reporter assay was used to determine the effect of NAMPT and imatinib on transcriptional activity of NF-κB transcription factors. The results showed that after exposure to 1 µmol/L imatinib for 3 - 48 h, there was no significant change of NAMPT expression in K562 cells. The expression of NAMPT could be effectively inhibited by the NAMPT-siRNA. After exposure to 1 µmol/L of imatinib for 48 h, the survival rate of NAMPT-siRNA interference group was lower than that of negative control group (P < 0.05), indicating that suppression of NAMPT expression can increase the sensitivity of K562 cells to imatinib and enhance the killing effect of imatinib on K562 cells. The IC(50) of imatinib in NAMPT-siRNA interference group was the lowest compared with that of control group (P < 0.05) after exposure to different concentrations of imatinib for 48 h, the fitted survival curves showed that the slope of NAMPT-siRNA interference group was the largest ranging between 0.01 - 0.1 µmol/L of imatinib. Data mining of expression profiling indicated that the anti-apoptotic factor Bcl-2 decreased in K562 cells treated with either NAMPT-siRNA or imatinib, which was confirmed by Western blot. The inhibitory effect was much more significant when both NAMPT-siRNA and imatinib were used. The results of luciferase reporter assay showed that either NAMPT-siRNA or imatinib decreased transcriptional activity of NF-κB. The decreased effect was much more significant when both NAMPT-siRNA and imatinib were used. It is concluded that survival of K562 cells affected by imatinib may not be due to regulation of expression of NAMPT. When expression of NAMPT decreases, the K562 cells are more sensitive to imatinib, this may be related with the decreased transcriptional activity of NF-κB and its downstream effector Bcl-2.

Design and development of a military medical sci-tech novelty retrieval management system / 军事医学科学院院刊

Objective:To develop a novelty retrieval management system to meet actual demands of military medical sci-tech novelty retrieval. Methods:Delphi 7.0, Access 2000 and SQL Server 2000 were employed as the developmental platform to realize the system functions.Results and Conclusion:The military medical sci-tech novelty retrieval management system can exercise overall management and improve the quality and efficiency of novelty retrieval, which will provide information and decision assistance for management of medical researches.

Study on the establishment of data management system of emergency response in fighting against flooding in China / 中华流行病学杂志

<p><b>OBJECTIVE</b>To make the emergency response to the diseases control and prevention with flooding more scientific ally-based and efficient.</p><p><b>METHODS</b>Hubei and Jiangxi province were chosen as the study fields and to establish a data management system of emergency response on flooding using remote sensing (RS) and geographical information system (GIS).</p><p><b>RESULTS</b>Spatial and basic data together with data on flooding were linked to the code of location, and established on the platform of GIS. Through this system, information on flooding was able to be more rapidly and visually analysed.</p><p><b>CONCLUSION</b>Using this system, the extent of flooding and the possible epidemic of some communicable diseases during flooding could be ascertained and predicted scientifically and the resource and capacity of emergency response to the disease control and prevention in flooding areas could also be evaluated.</p>