At present, the research regarding repair of spinal cord mainly focuses on tissue engineering. Neural tissue engineering materials provide three-dimensional template for tissue regeneration and also environment for synthesis of extracellular matrix. This paper summarizes the types of nerve transplant materials and the research progress in application for treatment of spinal cord injury, so as to provide theoretical evidence for repair of spinal cord injury. But some problems exist in application of nerve cell scaffold materials for repair of spinal cord injury: poor mechanical properties lead to slow degradation speed, causing difficulties in tissue reconstruction with respect to velocity and in subsequent reconstruction of porous three-dimensional scaffold. In recent years, novel biomaterials with specific repair function have been made by the engineering method through combining the biological molecule with specific signal identification function and available materials, which is an advanced projeot in the current field of biomaterials.

Objective To discuss the impact of relevant psycho-social factors on the driving adaptability. Methods A total of 870 vehicle drivers were screened out by stratified cluster sampling,and 620 drivers were finally selected for this study after eliminating those who had 1 -2 accidents. The 620 drivers were divided into accident group and non-accident group. Demographic questionnaire, life event scale, SCL-90 Scale and Eysenck Personality Questionnaire were applied to investigate their general condition, life event, mental health and personality. All data were analyzed by t test and stepwise Fisher discriminatory, and then the discriminatory equations of driving eligibility were established. Results The scores of factors including positive life events, negative life events, family events, work events and social events in accident group were 9.62 ± 11.36, 34.53 ± 30.01, 24.05 ± 23.09, 16.78 ± 17. 12 and 2.82 ± 5.07, respectively, which were higher than 4.67 ± 6.25, 6.38 ± 10. 15, 6.48 ± 9.43, 3.96 ±6.55 and 2.02 ± 5.43 respectively in the non-accident group ( P ＜ 0. 01 ). The total SCL-90 score and the scores of all factors in the accident group were higher than those in the non-accident group ( P ＜0. 01 ). The Eysenck Personality Questionnaire scores of the accident group were significantly higher than the non-accident group in N dimension ( 56. 32 ± 8.77 vs. 45.23 ± 8.06 ) and P dimension (52.22 ±10.43 vs. 48.31 ± 9.35 ) ( P ＜ 0. 01 ). Fisher discriminatory equations: Faccident group = 0. 258 × X6 + 0.119 ×X9 +0.637 ×X17 +0.043 × X5-7.476; Fnon-accident group =0. 137 × X6-1. 000 ×X9 + 1.423 ×X17 +0.003× X5-2.601. Total discrimination accuracy of verification was 88.3%, and the total accuracy of prospective discrimination was 88.0%. Conclusions There is clear correlation of driving adaptability with coercion, anxiety, emotion and negative factors. The discriminatory equations are useful for selecting drivers because of high accuracy, and may play an important role in reducing the occurrence of traffic accidents.

Objective To establish a mouse model of biliogenic severe acute pancreatitis (SAP) by using a self-made device for retrograde injection of sodium taurocholate into common bile duct,and to investigate the improvement of the device on retrograde injection of sodium taurocholate into common bile duct and its safety.Methods Thirty-six adult male ICR mice were randomly divided into biliogenic SAP model group and sham group,with 18 mice in each group.A 40 U disposable insulin syringe,a 200 μL tips and a 25 μL micro-syringer were used as basic materials for making the mouse common bile duct injection device [National Utility Model Patent (ZL 2014 2 0694365.4)].In model group,3.5％ sodium taurocholate (1 mL/kg) was injected retrogradely into the common bile duct of mice,whilst in sham group,the mice underwent the injection of equal amount of normal saline instead.Six mice in each group were sacrificed at 6,24 and 48 hours after operation,and the abdominal aortic blood was collected.Serum amylase (AMY),alanine aminotransferase (ALT),creatine kinase-MB (CK-MB),serum creatinine (SCr),oxygenation index (PaO2/FiO2) as well as serum Ca2+ were.determined.Pathological change in pancreas was observed under conventional light microscopy after hematoxylin and eosiu (HE) staining,and the impairment was evaluated by a widely used score system.Results The injection device was easily placed into mouse common bile duct under macroscopic observation.Six hours after operation,the levels of serum AMY,ALT and SCr in model group were significantly higher than those in sham group,and peaked at 24 hours,and they slightly decreased at 48 hours,which were still significantly higher than those of the sham group [24-hour AMY (U/L):7 325 ± 1 154 vs.1 737 ± 197,24-hour ALT (U/L):176.0±5.0 vs.38.3 ± 2.0,24-hour SCr (tmol/L):46.3 ± 1.5 vs.17.8 ±0.6,all P ＜ 0.01].The level of CK-MB at 6 hours in the model group was significantly higher than that of the sham group,and peaked at 48 hours (U/L:749.8±42.2 vs.383.3±35.5 at 6 hours,3 340.1 ± 203.6 vs.704.6 ± 63.5 at 48 hours,both P ＜ 0.01).PaO2/FiO2 at 6 hours after the operation in model group was significantly lower than that of sham group,then it began to rise at the similar level in sham group at 48 hours [mmHg (1 mmHg =0.133 kPa):327.5±33.8 vs.424.8±31.0 at 6 hours,P ＜ 0.01;429.8 ±41.8 vs.464.7±43.3 at 48 hours,P ＞ 0.05].Ca2+ level in model group was continuously decreased after operation,and it was significantly lower than that of sham group at 48 hours (mmol/L:1.58 ± 0.14 vs.2.45 ± 0.21,P ＜ 0.01).The pancreatic edema was obvious after operation in sham group,with the observation time prolongation,the changes were gradually improved;pancreatic focal necrosis was found at 6 hours after operation in model group,and it was secondary aggravated,and pancreatic lobule structure disappearance and inflammatory cells extensive infiltration was found at 48 hours.Pathological score of the model group was significantly higher than that of sham group at each time point,and peaked at 48 hours (13.3 ±0.3 vs.3.0±0.1,P ＜ 0.01).Conclusion It is a highly efficient and low-cost way to induce biliogenic SAP in mice by retrograde injection of 3.5％ sodium deoxycholate into common bile duct via the self-made injection device,and the model conformed to the clinical characteristics of biliogenic SAP.

[ABSTRACT]AIM:ToinvestigatewhethermiRNA-24isinvolvedintheregulationofendothelialnitricoxide synthase ( eNOS ) expression and vascular endothelial cell proliferation .METHODS: A plasmid that highly expressed miRNA-24 was constructed, and was transfected into the human umbilical vein endothelial cells (HUVECs) by liposome. The cell proliferation was detected by MTT assay .The expression of eNOS and Sp 1 at mRNA and protein levels was exa-mined by real-time PCR, immunohistochemistry and Western blotting .RESULTS:Compared with control group , the pro-liferation of endothelial cells in miRNA-24 group was significantly decreased by 41.97 % (0.47 ±0.04 vs 0.81 ±0.03, P<0.01), and the expression of eNOS at mRNA and protein levels was decreased by 44.8% (0.48 ±0.01 vs 0.87 ± 0.03, P<0.05) and 71.92%(0.16 ±0.06 vs 0.57 ±0.08, P<0.05), respectively.Meanwhile, the mRNA and pro-tein levels of Sp1 were significantly decreased by 53.00% (0.45 ±0.02 vs 0.93 ±0.01, P<0.05) and by 62.31%(0.13 ±0.07 vs 0.31 ±0.09, P<0.05), respectively.In miRNA-24 inhibitor group, the above indexes were decreased compared with control group , but significantly increased compared with miRNA-24 group.CONCLUSION: miRNA-24 significantly inhibits the proliferation of HUVECs and the eNOS expression .Sp1 possibly acts as one of the important factors in the regulation of eNOS expression by miRNA-24.

To develop a low-cost, reliable, easy-to-maintain and practical instrument for protein purification. Some ultraviolet luminescent diode was used to provide 280 nm light source, and high-sensitivity S1336 photo-electric detector was employed for real-time monitoring of purified protein solution flowing through quartz cell to supervise the concentration of the protein. The instrument gave voice alarm and stopped working in case the protein concentration was less than the standard one. The lower SCM monitored the liquid level of the protein collecting cup and the position of loading arm through laser infrared distance sensor, so that a cup full of protein might be replaced by another empty cup. The instrument involved in Samsung S5PV210 embedded master computer, Wince6.0 operating system, Keil4.0 and VS2005. Trials proved that the instrument could perform real-time monitoring and curve display of dual-channel ultraviolet absorption, and could realize auto collection of 735 ml protein solution and up to 5-hour standby. The instrument developed has simple structure, high reliability and easy maintenance, and meets the desired require-ments.

Objective To study the prevalence of the mtDNA A1555G gene mutation in Chinese population with nonsyndromic hearing impairment.Methods PCR-RFLP,directional sequencing of PCR products were applied in 325 patients with nonsyndromic hearing impairment and 50 normal controls.Results The mutation rate of the mtDNA A1555G was 14.5% (47/325),28 of 47 cases were homozygosis,19 of 47 cases were heterozygosis.The same mutation was not detected in the control subjects.Conclusion The mutation rate of the mtDNA A1555G is relatively high in the Chinese NSHI patients,the mutation type includes both heterozygosis and homozygosis.

OBJECTIVETo identify the self-preparation monoclonal antibody which target to clenbuterol, and set up the standard curve to clenbuterol (CL) detection.

METHODSThe affinity constants and activity of the monoclonal antibody which target to CL were determined by ELISA. ELISA was also used to confirm whether the monoclonal antibody had any across-reaction with BSA and CL analogues. The rat ascites which contains the monoclonal antibody target to CL was purified by (NH4)2SO4 salt-out method and further by affinity column. At last, the CL detection standard curve which based on indirect competition ELISA was established.

RESULTSThe ELISA experiment showed that the antibody titer was 10(6) and the monoclonal antibody affinity constants was 2.90 x 10(10) L/mol. The result of the indirect competition ELISA confirmed that the monoclonal antibody had no cross-reaction with BSA and a few kind of CL analogue. CL detection standard curve based on indirect competition ELISA was established, which R2 was 0.9812, and the lowest detectable limit was 1.0 ng/ml.

CONCLUSIONThe standard curve based on indirectly competitioning ELISA was established. The self-preparation monoclonal antibody which target to CL has high affinity and high specific to CL, which had established the foundation to the advanced development of the CL immune test paper and CL ELISA kit.

Animals ; Antibodies, Monoclonal ; chemistry ; isolation & purification ; Antibody Affinity ; Clenbuterol ; immunology ; Cross Reactions ; Enzyme-Linked Immunosorbent Assay ; Limit of Detection ; Rats

BACKGROUNDAdipose-derived stromal cell (ADSC) differentiation into neural cells in vitro is becoming widely studied. However, there are few reports on astrocytes following differentiation, and particularly on maturation and electrophysiology. In this study, we used various methods to determine ADSC-derived astrocyte maturity.

METHODSChemical induction with isobutylmethylxanthine (IBMX) was used to differentiate adult ADSCs into astrocytes followed by hematoxylin-eosin (HE) staining to observe morphology and transmission electron microscopy for cellular ultrastructure assessment. Immunofluorescence was used to detect expression of neural stem cell marker nestin as well as glial markers glial fibrillary acidic protein (GFAP) and S-100. In addition, we measured membrane potentials in bis-(1,3-dibarbituric acid) trimethine oxanol-labeled ADSCs and astrocytes by stimulation with a high potassium solution under an inverted fluorescence microscope. Finally, cell cycle distribution was detected by flow cytometry.

RESULTSTypical astrocyte morphology was shown by HE staining after 48-hour differentiation. Glial fibril was observed with transmission electron microscopy. GFAP and S-100 were not expressed in the control group, but were expressed within 24-hour differentiation and reached a maximum at day 14 with no change up to day 28. Nestin was weakly expressed in control cells and also reached a maximum at day 14 with the percentage of positive cells constant until day 21 followed by a decrease. Differentiated cell membrane potentials after stimulation with potassium were slightly increased, and then gradually declined over time. There was no significant membrane potential change in the control group. Flow cytometry showed that the percentage of cells in G0/G1 phase was 93% and only 5% in S phase.

CONCLUSIONADSCs were differentiated into mature astrocytes with typical characteristics including morphology, ultrastructure, marker protein expression, mature potassium channels and mitotic capacity.

1-Methyl-3-isobutylxanthine ; pharmacology ; Adipose Tissue ; cytology ; Adult ; Astrocytes ; cytology ; Barbiturates ; pharmacology ; Cell Differentiation ; drug effects ; Cells, Cultured ; Electrophysiology ; methods ; Female ; Flow Cytometry ; Glial Fibrillary Acidic Protein ; metabolism ; Humans ; Male ; Membrane Potentials ; drug effects ; Microscopy, Fluorescence ; S100 Proteins ; metabolism ; Stromal Cells ; cytology ; Young Adult

Objective Our previous study has shown that porcine antigen-primed and CD4 + T cells activated macrophages are capable of the ecognition and rejection of porcine xenografts but not mouse allografts, and therefore suggested the involvement of signaling between the graft and macrophages in this specific graft recognition and destruction. Methods NOD-SCID mice were transplanted with fetal pig pancreatic fragment (FPP) before adoptive transfer with exogenous macrophages isolated from rejecting FPP xenografts of BALB/c recipient mice. The exogenous macrophages were tracked by Ly5.1 surface antigen or via CSFE staining. Gene expression of CCR2 and CCR5 and their chemokines in transplanted FPP xenografts was evaluated by real-time PCR. Results After the adoptive transfer, recently transplanted but not established FPP xenografts were rejected by exogenous activated macrophages. In the meantime, greater level of chemokine gene expression was detected in recently-transplanted compared with the established xenografts. Furthermore, expression of both CCR2 and CCR5 genes was enhanced significantly in activated macrophages when compared with non-activated macrophages. Conclusion Upregulated chemokines were associated with macrophage recruitment and destruction of islet xenografts.

Objective:To investigate the MRI features of perirenal space involvement in patients with acute pancreatitis (AP) and its correlation with disease severity.Methods:A total of 128 AP patients admitted to Bishan District People′s Hospital of Chongqing from June 2018 to June 2020 were selected as study subjects. All patients were diagnosed by ultrasound guided percutaneous biopsyand the pathological diagnosis results were taken as the gold standard. The accuracy, sensitivity and specificity of MRI diagnosis were calculated to analyze the correlation between MRI features of perirenal space involvement and MRI severity index (MRSI).Results:Among the 128 patients, 96 patients with perirenal space involvement in AP confirmed by ultrasound guided percutaneous biopsyand the pathological diagnosis results, accounted for 75.00%. The sensitivity, specificity, accuracy, positive predictive value and negative predictive value diagnosed by MRI were 95.83%, 93.75%, 95.31%, 97.87% and 88.24% respectively. The involvement rate of perirenal space in AP was 75.00%(96/128), and that in mild, moderate and severe AP was 52.38%(22/42), 93.62%(44/47) and 7/7, respectively. Forty-two mild patients presented abnormal signals in the pancreas, or focal and diffuse pancreatic enlargement, thickening, and abnormal streak signalabnormalities in perirenal space, perirenal MRI showed grade 1 and 2. Forty-seven patients with moderate disease showed patchy signal abnormalities in the perirenal space, and perirenal MRI showed grade 3. Seven severe patients found perirenal interstitial effusion which was patchy. There was a good correlation between MRI features grade of perirenal space involvement and MRSI ( r = 0.721, P<0.001). The consistent rate of MRI features score of the right perirenal space was 91.14%, the consistent rate of MRI features score of the left perirenal space was 95.38%, and the consistent rate of MRSI observation on both was 90.21%. Conclusions:MRI can effectively and accurately diagnose perirenal space involvement in AP patients, MRI features and involvement rate can accurately reflect the severity of AP, which has a positive effect on clinical diagnosis and treatment of patients with perirenal space involvement in AP.