BACKGROUND: Schwann cells are the only glial cells in the peripheral nervous system and play an important role in the regeneration of peripheral nerves, while they have poor proliferation capacity and decreased activity, need allografts, and are difficult to culture in vitro. OBJECTIVE: To analyze the feasibility of repairing neurologic defects with tissue-engineered nerves constructed with Schwann cells derived from bone marrow stromal stem cells. DESIGN, TIME AND SETTING: Randomized controlled observation was conducted at Heilongiiang Institute of Veterinary Pharmaceutics between March 2004 and April 2005.MATERIALS: Twenty-four 8-weck-old female Wistar rats were used to establish animal models with 10 nun defect of sciatic nerve. METHODS: Twenty-four rats were divided into 3 groups by random digits table, tissue-engineered nerve group, polylactic acid robe group and autologons nerve group, with 8 rats in each group. Tissue-engineered nerve group: tissue-engineered nerve Was used to bridge neurologic defect, which was constructed with Schwann cells derived from bone marrow stromal stem cells, natural extracelhilar matrix gel and degradable polylactic acid tube. Polylactic acid robe group: injecting extracellular matrix gel into degradable polylactic acid tube to bridge neurologic defect. Autologous nerve group: 10 mm of nerve was cut and performed end-to-end anastomosis after revolving 180 degrees. MAIN OUTCOME MEASURES: Functional recovery of sciatic nerve was detected with electrophysiological observation of nerve, and histological observation and axon count of the newly generated nerve tissue at 12 weeks after transplantation. RESULTS: After introduction, adult bone marrow stromal stem cells had the morphology and properties of Schwann cells. The regenerated nerve had grown to the distal end passing through the defect at 12 weeks after transplantation. The detection indexes in the tissue-engineered nerve group and autologous nerve group were better than that in the polylactic acid tube group (P < 0.05), there were no significant differences between the tissue-engineered nerve group and autoiogous nerve group (P < 0.05); The degradation and absorption of polylactic acid tube were obvious in the tissue-engineered nerve group and autologous nerve group. CONCLUSION: Human bone marrow stromal stem cells can be induced to differentiate into Schwann cells in vitro, and tissue-engineered nerve constructed with Schwann cells, extracellular matrix and degradable polylactic acid tube can repair peripheral neurologic defect.

[Objective]To determine the biological effects of transfection of adeno-associated rirus(AAV) BMP4/7 on rabbit bone marrow stromal cells (BMSCs).[Method]The mature peptide of BMP4 and BMP7 were gained by One-Step RT-PCR from the human placenta and the BMP4/7 fusion gene was gained through gene recombinant techniques and then transferred to pGEM plasmid. The BMP4/7 fusion genen was cut down from the pGEM-BMP4/7 and the recombination was successfully completed in colibacillus, and recombinant adeno-assosiated was produced in 293 cells. Rabbit BMSCs were transfected with the recombinant adeno-assosiated virus vectors carrying BMP4/7 fusion gene with differen multiplicitv of infection(MOI) values. Cell growth curves were drawn to evaluate the biologic effect of AAV-BMP4/7 on cyto-activity. The transfection efficiency was measured using MTT method. The ossification of cells was evaluated by investigating the shape change of the cell ability of ALP and OC at 7,14 days after transfection. Cells were then transfected with AAV-BMP4/7 and AAV-EGFP,respectively.[Result]1.We successfully constructed the recombinant adeno-assosiated virus with BMP4/7 fusion gene.2.The ttransfection efficiency of AAV-BMP4/7 was roughly 72% without siginifficant biologic effect on cyto-activity.The ossification of cells was significant after transfection with AAV-BMP4/7. The 1?105 vg/cell MOI value of transfection efficiency was stroger than 5~104 vg/cell MOI value (59.3,8%). 3. The concentrations of ALP and OC in AAV-BMP4/7 transfection groups were significantbly higher than in AAV-EGFP groups (tALP=896.88 P

Objective To explore the application value of real-time three-dimensional echocardiography (RT-3DE) in diagnosis of structural heart disease through a comparison with two dimensional echocardiography (2DE).Methods Ninety-two patients with heart disease were enrolled from October 2009 to February 2014 , all of whom were examined by RT-3DE.By cutting and spiraling structural 3D images of lesions in regions of interest , we made a diagnosis of lesions .In addition, the size of atrial(ASD) and ventricular septal defects (VSD),based on surgical results,was measured and analyzed.By comparing the coherence and difference of diagnosis on structural heart disease examined by 2DE and RT-3DE, the accuracy and superiority of RT-3DE were evaluated.Results (1)The 3D images of 92 patients with heart disease were successfully obtained by RT-3DE.The structure of lesions was displayed directly from various angles .In addition, the position, scope and degree of lesions and the spatial relationship of adjacent structures were accurately confirmed.RT-3DE provided more direct, accurate and abundant information than 2DE.(2)In the diagnosis of congenital heart disease, the diagnostic accordance rate of RT-3DE was the same as that of 2DE, but was slightly higher in the diagnosis of valvular disease and other lesions .( 3 ) Compared with 2DE, the ASD maximum diameters obtained from RT-3DE were more correlaed with surgical findings (r=0.94,0.86),so were the VSD maximum diameters (r=0.93, 0.84).Conclusion RT-3DE is easy to operate and quick to produce image ,which can provide more spatial information than 2DE in structural heart disease diagnosis , increase the accuracy rate of diagnosis , and serve as a supplement to 2DE.

Objective To observe the different cerebral activations between pre-administration and post-administration of tryptophan-depleted amino acid mixture (TRP-)/balanced amino acid mixture (BAL) in healthy volunteers through functional magnetic resonance imaging (fMRI) when they received electrical stimulation at the same time. Furthermore, the effects of 5-hydroxytryptamine (5-HT) were explored in pain modulation network. Methods Two-phase crossover design was adopted. Six right-handed healthy volunteers participated in the experiment. TRP- and BAL were administered to each participant according to the Young's method. Volunteers were scanned under fMRI with or without administration of TRP- or BAL when receiving electrical stimulation simultaneously. Analysis of functional neuroimages (AFNI) software was used to show the different activations in the human brain between pre- and post-administration of TRP-/BAL. Then all the results were analyzed by SPSS 14.0. Results (1) Bilateral primary somatosensory cortex (SⅠ) and secondary somatosensory cortex (SⅡ) were activated during pre-administration and post-administration of TRP-, but the activated volumes of bilateral SⅠ and SⅡ during post-administration of TRP- were found significantly larger than that during pre-administration of TRP (P＜0.05). (2) All the activated regions showed no difference between pre- and post-admini-stration of BAL. (3) There were significant differences of pain threshold between pre- and post-admini-stration of TRP- (P＜0.01), which meant that pain threshold reduced remarkably after TRP- administration, while it showed no difference between pre- and post-administration of BAL (P＞0.05). Conclusion 5-HT plays an important role in pain modulation in the central nervous system, TRP- causes acute tryptophan depletion (ATD) through reducing the level of 5-HT in the human brain, which can induce the decrease of volunteers' pain threshold. The activated volumes of bilateral SⅠ and SⅡ display signi-ficant difference between pre- and post-administration of TRP-, suggesting these brain areas may not only involve in the 5-HT related activities but in pain modulation network as well.

Objective Laminectomy is destructive to bone structure in spine , which affect spinal stability .This article was to investigate the effect on spinal stability after laminectomy in different segments of vertebral plate in the treatment of lumbar intraspinal tumors. Methods Retrospective analysis were made on the data of 143 patients with lumbar intraspinal tumors from January 2009 to June 2012 in 6 hospitals.All the patients underwent laminectomy with no use of inner regular apparatus during the operation .JOA evalu-ation was applied to observe short-term efficacy , while ASIA scale for long-term efficacy .Comparison was made on lumbar spinal stability before operation and in the last visiting . Results From the observation of short-term efficacy, JOA evaluation score rised from (1.12 ± 0.65)to (1.97 ±0.71).Form the observation of long-term efficacy, ASIA scale classification was as follows:4 cases of Grade I, 6 cases of Grade II, 14 cases of Grade III, 53 cases of Grade IV and 66 cases of Grade V.In the following 12-30 months′visiting, all patients were covered.In the last postoperative visiting, patients suffering spinal instability after laminectomy were as follows:2 of 45(one seg-ment), 9 of 47(two segments), 5 of 27 (three segments) and 2 of 14 (four segments).From the observation on the postoperative spinal sta-bility and the segments in laminectomy , spinal stability of one-segment group was significantly higher than that of multi-segment group ( P=0.047).No significant difference exist between the groups of less than 2 segments and more than 3 segments as well as the groups of less than 3 segments and more than 4 segments. Conclusion A single seg-ment laminectomy on lumbar intraspinal tumors showed good postopera-tive spinal stability .But laminectomy in two or more segments implied greater risk of postoperative spinal instability .

Objective To evaluate the effects of problem-based learning (PBL) teaching model in medical imaging education in China. Methods Such databases as PubMed, Medline, CNKI, WanFang, VIP Data were electronically searched for literature on PBL versus lecture-based learning (LBL) applied in medical imaging education in China up to April, 2015. According to the strict quality evaluation of the in-cluded studies, meta-analysis was performed using RevMan 5.2 software. Results Fourteen studies were included totally. Studies included 1 233 students, of whom the PBL group had 608 cases, while LBL group had 625 cases. Compared with LBL, PBL was superior in medical imaging theoretical scores [WMD=5.22, 95%CI(3.06, 7.37), P=0.000], and the case analysis scores [WMD=6.45, 95%CI(4.77, 8.12), P=0.000]. PBL was also superior in the autonomous learning ability [RR=1.78, 95%CI (1.47, 2.16), P=0.000], the unity cooperation ability [RR=1.42,95%CI (1.25, 1.61), P=0.000] and analysis ability [RR=1.73,95%CI (1.42, 2.11), P=0.000]. There were significant differences between PBL group and LBL group. Conclusion PBL can improve teaching results in medical imaging education.

PURPOSE: Cancer-associated fibroblasts (CAFs) activated by cancer cells has a central role in development and malignant biological behavior in colorectal cancer (CRC). Adult fibroblasts do not express Snail, but Snail-positive fibroblasts are discovered in the stroma of malignant CRC and reported to be the key role to chemoresistance. However, the reciprocal effect of CAFs expressed Snail to chemoresistance on CRC cells and the underlying molecular mechanisms are not fully characterized. MATERIALS AND METHODS: Snail-overexpressed 3T3 stable cell lines were generated by lipidosome and CT26 mixed with 3T3-Snail subcutaneous transplanted CRC models were established by subcutaneous injection. Cell Counting Kit-8, flow cytometry and western blotting assays were performed, and immunohistochemistry staining was studied. The cytokines participated in chemoresistance was validated with reverse transcriptase-polymerase chain reaction and heatmap. RESULTS: Snail-expression fibroblasts are discovered in human and mouse spontaneous CRCs. Overexpression of Snail induces 3T3 fibroblasts transdifferentiation to CAFs. CT26 co-cultured with 3T3-Snail resisted the impairment from 5-fluorouracil and paclitaxel in vitro. The subcutaneous transplanted tumor models included 3T3-Snail cells develop without restrictions even after treating with 5-fluorouracil or paclitaxel. Moreover, these chemoresistant processes may be mediated by CCL1 secreted by Snail-expression fibroblasts via transforming growth factor β/nuclear factor-κB signaling pathways. CONCLUSION: Taken together, Snail-expressing 3T3 fibroblasts display CAFs properties that support 5-fluorouracil and paclitaxel chemoresistance in CRC via participation of CCL1 and suggest that inhibition of the Snail-expression fibroblasts in tumor may be a useful strategy to limit chemoresistance.
Adult ; Animals ; Blotting, Western ; Cell Count ; Cell Line ; Colorectal Neoplasms* ; Cytokines ; Drug Resistance, Multiple ; Fibroblasts* ; Flow Cytometry ; Fluorouracil ; Humans ; Immunohistochemistry ; In Vitro Techniques ; Injections, Subcutaneous ; Mice ; Paclitaxel ; Snails ; Transforming Growth Factors

Objective To explore the utility of CT for the evaluation of abdominal aortic calcification(AAC)in chronic kidney disease(CKD).Methods Laboratory examination indexes and abdominal plain CT imaging of 132 CKD stage 3-5 patients were analyzed retrospectively.The ACC score was evaluated according to quantitative method,the risk factors related to AAC were analyzed.Results In correlation analyses,AAC score was positively correlated with creatinine(Cr)level,CO2 combining power(P＜0.05),and negatively corrected with albumin(ALB).Logistic regression analysis showed that Cr level were risk factors for AAC,and ALB were protective factors.Conclusion Based on abdominal plain CT images,Cr level,CO2 combining power and ALB level are related to AAC.Quantitative method based on CT has a high application value in evaluating AAC.