Objective To observe three-dimensional structure and biological features of rat acellular spinal cord scaffold prepared by sonic oscillation and chemical extraction in order to offer an ideal scaffold for spinal cord tissue engineering research.Methods Rat spinal cord underwent acellular treatment with sonic oscillation and chemical extraction (Triton X-100 at volume fracture of 2％ and sodium deoxycholate at volume fracture of 2％) (acellular spinal cord group).In contrast with spinal cord tissue of normal rats (control group),general morphology,histology and ultramicro three-dimensional structure of acellular spinal cord scaffold were observed and aperture size,factor of porosity,water ratio,enzymolysis ratio and stability in water solution of the scaffold were also detected.Results Acellular spinal cord group showed effective removal of original cell components with factor of porosity for (94.57 ±3.45) ％ and water content for (88.62 ± 1.0) ％,and satisfactory three-dimensional structure with average aperture of 46 μm.Scaffold showed gradual degradation in enzymolysis solution and enzymolysis rate reached (69.03 ± 2.19)％ at 20 hours.Besides,scaffold showed stepwise disintegration in double distilled water and hydrolysis rate was (62.55 ± 1.70) ％ at 8 days.While,normal spinal cord showed close structure,generous neurons and myelin sheath with factor of porosity for (0.04 ± 0.02) ％ and water content for (62.4 ± 1.5) ％,and unobvious pore structure under scanning electron microscope.Normal spinal cord were degraded gradually in enzymolysis solution and enzymolysis rate was (37.62 ± 0.9)％ at 20hours.In the meantime,normal spinal cord were disintegrated gradually in double distilled water and hydrolysis rate was (40.97 ± 0.81) ％ at 8 days.Conclusions Acellular spinal cord scaffold prepared by sonic oscillation plus chemical extraction achieves complete removal of cell components,intact extracellular matrix,and satisfactory results in three-dimensional network structures,factor of porosity and water content.Also,the scaffold meets theoretical demands of tissue-engineered spinal cord scaffold and is an ideal alterative for tissue-engineered spinal cord scaffold.

Objective To construct genipin-crosslinked rat acellular spinal cord scaffolds and evaluate their enzymatic degradation rate,biomechanical properties and cytotoxicity.Methods Rat spinal cord scaffolds were decellularized by chemical extraction and chemically crosslinked with 5 g/L genipin solution.Micro-structure of the uncrosslinked and genipin-crosslinked acellular spinal cord scaffolds were observed by HE staining and scanning electron microscopy and properties of pore size,porosity,water ratio,and degradation rate in 2.5 g/L trypsin enzyme solution were examined.Ultimate tensile strength and elastic modulus of normal rat thoracic spinal cord,uncrosslinked and genipin-crosslinked acellular spinal cord scaffolds were determined on Instron mechanical testing instrument.Rat bone marrow mesenchymal stem cells were cultured in lixivium of uncrosslinked and genipin-crosslinked acellular spinal cord scaffolds and MTT assay for relative cell growth rate was test to evaluate the cytotoxicity of scaffolds.Results The uncrosslinked and the genipin-crosslinked acellular spinal cord scaffolds possessed a similar three-dimensional mesh-porous structure with a mean pore diameter about 30 μm and a porosity over 80％,but there was a statistical difference between the two groups(P ＞ 0.05).Water ratio of genipincrosslinked scaffolds was (229.7 ± 12.5) ％,far lower than (283.4 ± 11.2) ％ of uncrosslinked scaffolds (P ＜ O.05) ; genipin-crosslinked acellular spinal cord scaffolds had lower weight loss at each time point than the uncrosslinked acellular spinal cord scaffolds (P ＜ 0.05),but the stability in trypsin,ultimate tensile strength and elastic modulus of acellular spinal cord scaffolds were significantly enhanced by genipin-crosslinking (P ＜ 0.05).Furthermore,no obvious cytotoxicity was observed in the uncroslinked and genipin-crosslinked scaffolds.Conclusions Rat acellular spinal cord scaffolds present no obvious change in structure after genipin-crosslinking,but there is significant improvement in the biomechanical properties and ability against enzymatic degradation and no marked cytotoxicity.Hence,the genipincrosslinked scaffolds are promising in tissue engineering for spinal injury.

Objective To investigate the relationship between HLA antibodies strength and complement-binding ability in sensitized renal patients waiting for renal transplantation.Method Serum samples of 31 sensitized renal patients waiting for renal transplantation were retrospectively analyzed by single-antigen bead array (SAB) to identify HLA antibodies and in parallel by C1q-SAB to determine the complement binding of HLA antibodies.Result C1q-positive HLA antibodies had significantly higher MFI than C1q-negative HLA antibody (for Class Ⅰ,11052 ± 3291 vs.4506 ± 2960,P＜0.05;for Class Ⅱ,13347 ± 4076 vs.4448 ± 3602,P＜0.05).The mean fluorescence intensities (MFI) of IgG-SAB were correlated with the MFI of C1q-SAB for the same antibodies (Spearman correlation; Class Ⅰ,r =0.665,P ＜ 0.01 ; Class Ⅱ,r =0.761,P ＜ 0.01).Receiver operating characteristics (ROC) curve analysis showed that the MFIs of HLA antibodies by IgG-SAB could predict their C1q-binding abilities [area under the curve (AUC)Class Ⅰ =0.917; AUCclass Ⅱ =0.927).Using MFI cut-off value of 8238 and 6754 for HLA Class Ⅰ and Class Ⅱ antibodies,respectively,the sensitivity and specificity for C1q binding were 82.4％ and 87.4％ for Class Ⅰ antibodies,and 90.9％ and 82％ for Class Ⅱ antibodies,respectively.Conclusion The MFI of HLA antibodies by IgG-SAB can predict the C1q binding capability at a certain extent before transplantation.

Objective:To develop and optimize a novel assay for determination of cytotoxicity based Calcein -AM release.Methods:The target cells stained by Calcein-AM dye,then effectors and targets were incubated at E/T ratios from 30∶1-1∶1 for 4 h at 37℃,and the supernatant of reactions were detected by Fluorescence-Measurement to analyze specific cytotoxity.Results:The optimal excitation and emission wave lengths of Calcein were 485 nm and 515 nm.Dilutions of target cells stained by Calcein-AM had a linear relationship with measured fluorescence values.The Calcein-AM dye used to stain the living cells was shown to have a low spontaneous leakage rate-less than 15% in 4 hours at 37℃.Cytotoxicity activity of CIK showed a significant and positive correlation with E/T ratio when incubated at 4 h.Conclusion:The developed cytotoxicity test by Calcein-AM release is accurate and can avoid the application of radioactive reagents.

BACKGROUND:A novel biodegradable Mg-Zn alloy has been designed,in which the density and the Young's modulus are proximal to human bone,at the same time,it depletes the toxicity of aluminium and rare earth element in commercial magnesium alloys.OBJECTIVE:To evaluate the cytocompatibility of biodegradable Mg-Zn alloy.DESIGN,TIME AND SETTING:Contrast study was performed in the central laboratory of the Sixth People's Hospital of Shanghai Jiao Tong University between November 2007 and March 2008.MATERIALS:The Mg-6wt%Zn was prepared by School of Materials Science and Engineering of Shanghai Jiao Tong University,with the density was 1.82 g/cm3 and the Young's modulus was 44 GPa.L-929 cells for cytocompatibility test were provided by Chinese Academy of Science Type Culture Collection.Ten male New Zealand rabbits were employed in the hemolysis test.METHODS:The Mg-Zn alloy extraction medium was prepared by serial dilutions with fresh medium to 10%,50% and 100%.The experiments were carried out in a 96-well tissue-culture plate.Simple DMEM culture solution was taken as negative controls,while DMEM culture solution supplemented with 0.64% phenol served as positive controls.MAIN OUTCOME MEASURES:Relative proliferation rate of L-929 cells was determined at 2,4 and 7 days with MTT assay.The cytotoxicity of Mg-Zn alloy was evaluated according to ISO 10993-5:1999.The L-929 cell morphology and growth at 2,4 and 7 days were determined under inverted microscope.Based on ISO 10993-4:2002,hemolysis in vitro was evaluated through measuring erythrocyte lysis and ferrohemoglobin freeing degree with indirect contact method.RESULTS:The number of L-929 cells increased significantly and the morphology was not changed.The growth and morphology of cells in different Mg-Zn extraction medium had no difference from negative control group.Cytotoxicity test showed that biodegradable Mg-Zn alloy did not have obvious toxicity on L-929 cells,and the cytotoxicity of these extracts was in grade 0-1.Hemolysis test suggested that the Mg-Zn alloys did not have obvious hemolysis reaction,and the hemolysis index was 3.4%,which was less than the national standard (5%).CONCLUSION:The Mg-Zn alloys do not have obvious cytotoxicity and hemolysis reaction,which demonstrate that Mg-Zn alloys have good cytocompatibility.

Objective To investigate the degradation of dicalcium phosphate dehydrate-coated Mg-Zn alloy in vivo and bone formation. Methods Left femoral condyles were drilled in 72 New Zealand rabbits, and were randomly divided into experiment group (n＝24, implanted with dicalcium phosphate dehydrate-coated Mg-Zn alloy rods), Mg-Zn alloy control group (n＝24, implanted with Mg-Zn alloy rods) and poly-L-lactide acid rod group (n＝24, implanted with poly-L-lactide acid rods). Serum concentrations of Mg~(2+) were examined 1 d pre-operation, and 1 d, 1 week, 2 weeks, 5 weeks and 10 weeks post-operation in experiment group and Mg-Zn alloy control group. Operation sites were examined by X-rays at 3, 6, 12 and 18 weeks post-operation. After X-ray examination at each time point, 6 rabbits in each group were sacrificed, and subjected to histopathological observation of live and kidney tissues by HE staining. Tissues from condyles of femur were observed by HE staining and 2, 4, 6-trinitrophenol rosein staining, and mineral apposition rate of bone was calculated. Results There was no significant difference in the concentrations of serum Mg~(2+) at each time point between Mg-Zn alloy control group and experiment group (P>0.05). X-ray examination revealed gas emerged near the implants 3 weeks after surgery in Mg-Zn alloy control group. However, there was no obvious histological abnormality in liver and kidney tissues. The mineral apposition rate was higher and the degradation of material was lower in experiment group than those in the other two groups. Conclusion Dicalcium phosphate dehydrate-coated Mg-Zn alloy has a favourable biocompatibility, and degrades more slowly in vivo.

p53, as a transcription factor, is an important tumor suppressor gene and plays the key role in the p53-dependent gene regulatory network. Therefore, it is important to understand its biological function at the level of the whole system. In this paper, based on KEGG database and related literatures in English and Chinese, the interaction mode and quantitative relationship of the related molecules involved in p53 signaling pathway were extracted. By using S-system equations and 'Simulink' toolbox of Matlab7.0, a dynamic model of p53 signaling pathway was developed, and the dynamic regulatory characteristics of p53 signaling pathway were analyzed on model simulation. The results were in accord with the literatures and could reflect quantitatively the complex regulatory relationship between the interacting molecules involved in p53 signaling pathway. In addition, model simulation helped us find and identify the key molecules in this signaling pathway. Thus, this model can be used as a basis for the follow-up study of the relationship by precise and quantitative assessment.
Algorithms ; Computer Simulation ; Gene Expression Regulation ; Humans ; Models, Biological ; Signal Transduction ; physiology ; Transcription Factors ; genetics ; metabolism ; Tumor Suppressor Protein p53 ; genetics ; physiology

Objective To research the effect to the semen quality of the three operation methods of superiority of highly selective varicocele high ligation,transinguinal canal and laparoseopic of renovated polomo management of varicocele.Methods 561 patients in our hospital who charged by infertility had the operation were analyzed retrospectively and were recruited with primary varicocele above grade II for this study.These patients were divided into three group according to three kinds of operation methods of varicocele :group A was treated with highly selective varicocele high ligation and had 300 patients;group B was treated with transinguinal canal operation and had 181 patients; and group C was treated by laparescopic of renovated polomo operation with 80 patients.Through the comparing of the fertility ability of the three operation methods,to evaluate the therapeutic effect of the three methods.Results The increasing rates of the quality of semen in group B was higher than other groups if patients' ages were lower than 30.The increasing rates of the quality of semen in every group was also higher if patients' ages were lower than 30.No difference was found between three groups in natural conception rate (P＞0.05).Conclusion The methods of highly selective varieecele high ligation would be a better choice in the management of patients with primary varicecele because of higher quality of semen.

BACKGROUND: Perioperative treatment has become an increasingly important aspect of the management of patients with non-small cell lung cancer (NSCLC). Small-scale clinical studies performed in recent years have shown improvements in the major pathological remission rate after neoadjuvant therapy, suggesting that it will soon become an important part of NSCLC treatment. Nevertheless, neoadjuvant immunotherapy may be accompanied by serious adverse reactions that lead to delay or cancelation of surgery, additional illness, and even death, and have therefore attracted much attention. The purpose of the clinical recommendations is to form a diagnosis and treatment plan suitable for the current domestic medical situation for the immune-related adverse event (irAE). METHODS: This recommendation is composed of experts in thoracic surgery, oncologists, thoracic medicine and irAE related departments (gastroenterology, respirology, cardiology, infectious medicine, hematology, endocrinology, rheumatology, neurology, dermatology, emergency section) to jointly complete the formulation. Experts make full reference to the irAE guidelines, large-scale clinical research data published by thoracic surgery, and the clinical experience of domestic doctors and publicly published cases, and repeated discussions in multiple disciplines to form this recommendation for perioperative irAE. RESULTS: This clinical recommendation covers the whole process of prevention, evaluation, examination, treatment and monitoring related to irAE, so as to guide the clinical work comprehensively and effectively. CONCLUSIONS Perioperative irAE management is an important part of immune perioperative treatment of lung cancer. With the continuous development of immune perioperative treatment, more research is needed in the future to optimize the diagnosis and treatment of perioperative irAE.