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Objective:To dynamically trace the migration and therapeutic effects of human bone marrow mesenchymal stem cells (MSCs) in mice with liver injury after cell transplantation through in vivo bioluminescent imaging (BLI).Methods:The MSCs were transfected with the lentivirus CMV-Luciferase2-mKate2 and mKate2 positive cells were purified and screened by fluorescence-activated cell sorting (FACS) after 96 h. The purified MSCs-R (MSCs-CMV-Luciferase2-mKate2) were used by in vitro and in vivo BLI. The mice (male BALB/c nude mice) were divided into 4 groups with 9 mice per group by random number table method, including (1) Liver injury experimental group: The liver injury model was established by intraperitoneal injection of CCl 4, and MSCS-R transplantation through spleen injection was performed 24 h later; (2) Control experimental group: The same volume of phosphate buffer (PBS) was injected intraperitoneally, and MSCS-R transplantation through spleen injection was performed 24 h later; (3) Liver injury group: Liver injury model was established and PBS was injected into the spleen;(4) Blank group: The mice were intraperitoneally injected of PBS.BLI was performed daily after cell transplantation until light signals disappeared in the liver region, and the pathological examination of liver tissue was obtained 14 d after MSCs-R transplantation. Linear regression analyses were performed to determine the correlation between the optical signal intensity and the number of cells, and statistical differences of the optical signal intensity between liver injury experimental group and control experimental group were evaluated using the Student′s t test. Results:The MSCs were readily transfected with lentivirus CMV-Luciferase2-mKate2 for 96 h. The transfected MSCs were purified by FACS and more than 95% of MSCs were mKate2 positive. The optical signal intensity of MSCs-R detected by BLI in vitro significantly correlated with cell numbers in vitro (R 2=0.980). In both of liver injury experimental group and control experimental group, cell migration to the liver was observed on the first day after intrasplenic transplantation of MSCs-R, and the optical signal intensity in the area of liver of liver injury experimental group was higher than that of control experimental group ( t=15.476, P<0.001). The optical signal intensity in the hepatic area was observed in 11 d after transplantation in liver injury experimental group, compared to control experimental group in 5 d. Optical signal was not detected in mice in the other two groups. Histopathology showed that the degree of liver injury after MSCs-R transplantation was significantly lower in liver injury experimental group than control experimental group. Conclusions:The dynamical migration of MSCs transplanted to the spleen and settled in the damaged liver could be tracked by BLI, and liver injury can prompt MSCs directionally migrate to the damaged tissues and play their role in repairing liver injury.
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Background and Objectives@#Tracking of the tumor progression by MSCs-based therapy is being increasingly important in evaluating relative therapy effectively. Herein, Bioluminescence imaging (BLI) technology was used to dynamically and quantitatively track the hepatocellular carcinoma suppressive effects by human umbilical cord mesenchymal stem cells (UC-MSCs). @*Methods@#and Results: The stem cells present typical phenotypic characteristics and differentiation ability by morphology and flow cytometry analysis of marker expression. Then, the growth inhibition effect of conditioned medium and UC-MSC on H7402 cells was studied. It is found both the conditioned medium and UC-MSC can effectively decrease the proliferation of H7402 cells compared with the control group. Meanwhile, the relative migration of UC-MSC to H7402 is also increased through the transwell migration assay. In addition, a mice hepatoma tumor model was built by H7402 cells which can express a pLenti-6.3/DEST-CMV-luciferase 2-mKate2 gene. The effect of stem cells on growth inhibition of tumor in a mice transplantation model was dynamically monitored by bioluminescence imaging within 5 weeks. It has shown the bioluminescence signal intensity of the tumor model was significantly higher than that of the UC-MSC co-acting tumor model, indicating that the inhibition of UC-MSC on liver cancer resulted in low expression of bioluminescent signals. @*Conclusions@#The microenvironment of UC-MSCs can effectively inhibit the growth of liver cancer cells, and this therapeutic effect can be dynamically and quantitatively monitored in vivo by BLI. This is of great significance for the imaging research and application of stem cells in anticancer therapy.
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Objective:This paper aims to analyze the impacts of medicine centralized bidding and purchasing policy based on the relationship between the bid winners and the bidden prices. Methods: A data collection method was used to collect data from medicine centralized bidding and purchasing policy in 31 provinces and OLS method has been employed to analyze impacts of the number of bid winners on the medicine prices. Results:The results showed a positive correlation between the number of bid winners and the bidden prices, which was a counter-intuitive appeal. In the group of non-essential medicines, the number of bid winners had a stronger impact on the bidden prices than in the group of essential medicines. Conclusions:The current medicine centralized bidding and purchasing policy does not achieve the expected objective and needs to be further improved.
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BACKGROUND: Injectable artificial bone composite has been reported to consider as a moulding filler of vertebrae at the histology level; however, the therapeutic effect needs to be further studied at the level of axial pressure capacity. OBJECTIVE: To explore the axial pressure capacity of dogs with thoracolumbar fractures treated by injectable artificial bone composite. DESIGN, TIME AND SETTING: A randomized controlled animal experiment was performed at the Animal Laboratory of Shenzhen Longgang Central Hospital from September 2008 to January 2009. MATERIALS: Type I and type II vertebral pedicle screw systems were provided by Tianjin Zhengtian Medical Device Company Limited; injectable artificial bone composite, which was made of coral-hydroxylapatite compound, recombinant human bone morphogenetic protein-2 (Academy of Military Medical Sciences), and 2% chitosan solution (the Second Military Medical University of Chinese PLA and Shanghai Qisheng Biomaterials Institute), was manufactured according to the methods provided by Yin et al. METHODS: A total of 20 1-year-old healthy dogs were randomly divided into treatment and control groups with 10 dogs in each group. The model of those dogs with thoracolumbar fractures was made by imitating falling accidents; thereafter, the dogs in the treatment group were treated with vertebral pedicle screw system internal fixation and vertebroplasty by filling the injured vertebrae with injectable artificial bones. The control group was treated with vertebral pedicle screw system internal fixation alone. MAIN OUTCOME MEASURES: The maximum pressure intensity of injured vertebra, upper and lower vertebra at vertebral body center was detected using micro-computer pressure testing system after three months. RESULTS: The maximum pressure intensity at vertebral body center was not significant differences in the treatment group (100% cases) between injured vertebral body and its neighboring vertebral body, and axial loading was recovered. While that of 60% cases in the control group was significantly different (P
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BACKGROUND: Spinal cord can regenerate after injury in certain microenvironment. Olfactory ensheathing cells (OECs)have the characteristics of astrocytes and Schwann cells and can accelerate the spinal cord axonal regeneration.OBJECTIVE: To make injured thoracic cord rat models and observe the effect of OECs on injured spinal cord axonal regeneration.DESIGN: Observational experiment.SETTING: Second Affiliated Hospital of Sun Yat-Sen University.MATERIALS: The experiment was performed at the Second Affiliated Hospital of Sun Yat-Sen University from January 2001 to November 2002.Totally 20 adult SD male rats with the body mass of (380±20) g were provided by Experimental Animal Center of Sun Yat-Sen University (number of institution license SYXK2004-0020). There were DMEM culture solution with low glucose (L-DMEM, GibcoBRL), fetal calf serum (FCS) (Hyclone), myelin basic protein (MBP) (Sigma) and nerve growth factor receptor antibody (Sigma). They were divided into cell transplantation group and control group by the method of random digits table with 10 in each group.METHODS: The adult SD rats were anaesthetized and decapitated to obtain the whole olfactory bulb and then isolate olfactory nerve with a sterile operation. Thoracic cord injury models were established by modified Allen method. 10μL OECs suspension (2.5×1010 L-1) was injected into injured spinal cord of the cell transplantation group, whereas DMEM/F12 (1:1) culture solution of the same dose was injected in the control group. The influence of OECs on spinal cord axonal regeneration was observed by histological and immunohistochemical method 6 weeks after transplantation.MAIN OUTCOME MEASURES: ①OECs were identified by nerve growth factor receptor antibody staining. ②Repair of myelin sheath was observed by MBP staining. ③Nerve axonal regeneration was observed by argentaffin staining. RESULTS: Two rats in the cell transplantation group and 3 rats in the control group died, so totally 15 rats were involved in the result analysis. ①In the cell transplantation group,injured spinal meninges were integrated,but spinal cord became thin as compared with the normal spinal cord. By hematoxylin-eosin (HE) staining, multipolar cells appeared in injured region and the cells were fused excessively with myeloid tissues. It proved that survival OECs were integrated well within the host. New axons were clustered in bundles and infiltrated by small round lymphocytes. By argentaffin staining, regenerated axons grew in tissues of injured region, which mostly accompanied with fascicular-arranged multipolar cells. In the control group, spinal cord became thin markedly and spinal meninges were integrated. No new axon appeared in the injured spinal cord by HE staining. No regenerated axon appeared by argentaffin staining, either. ②In the cell transplantation group, most multipolar cells were clustered in bundles. A mass of positive granules of nerve growth factor receptor antibody appeared in cytoplasm, which further verified that OECs still survived and integrated well within the host 6 weeks after transplantation. Linear MBP positive fibers appeared in the injured region by MBP staining,which indicated that myelin-like substance appeared and drew closely in both ends of injured region. At the same time,MBP positive substance also appeared in the multipolar cells, which illustrated that transplanted OECs could induce the occurrence of myelin-like substance. No regenerated axon was found in the control group.CONCLUSION: Delayed transplantation of OECs can survive and induce the occurrence of myelin-like substance in injured spinal cord of adult rats.