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Objective To investigate the effects of bone mesenchymal stem cells (BMSCs)transplantation on the neurological function recovery of injured spinal cord and the underlying mechanism.Methods Rats were subjected to contusive spinal cord injury by using NYU spinal cord contusive impactor system ( NYC lmpactor).Seven days after spinal cord injury,the transplantation of BMSCs ( BMSCs group) or injection of PBS ( PBS group) was performed around the epicenter of injured spinal cord in rats.Basso-Beattie-Bresnahan (BBB) score was used to evaluate the function of spinal cord.The cavity volume of the injured spinal cord was measured and the axons in the injury center of spinal cord were examined under transmission electron microscopy.The BMSCs of the green fluorescent protein (GFP)transgenic rats were used to trace the transplanted cells and the survivor of BMSCs in the injured spinal cord and their differentiation into neural cells were observed.A mini-channel implantation model was employed to further investigate the role of BMSCs transplantation on the axonal regeneration.Results The BMSCs group showed a higher BBB score and a smaller lesion volume as compared with the PBS group.Transmission electron microscopy examination displayed that the number of axons in the BMSCs group was far more than that in the PBS group.A great number of BMSCs-GFP were founded around the center of the injured spinal cord at 4 weeks after BMSCs transplantation.lmmunohistochemistry showed that the implanted BMSCs-GFP did not express the surface marker of neurons,astrocytes and oligodendrocytes.In the mini-channel implantation model,NF-positive nerve fibers grew into the BMSCs-seeded channel,while there were no nerve fibers in the channel without seeding of BMSCs.Conclusions The BMSCs transplantation for the injured spinal cord promotes its functional recovery,and the related mechanism is in correlation with BMSCs transplantation inducing axonal regeneration.
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ObjectiveTo investigate the impact of metal plate on radiation dose distribution by Monte Carlo (MC) code. MethodsThe metal plates with 0. 4 thick were placed in water at 5 cm, all the plate irradiated with 6 MV X-ray were simulated by MC code, SSD =100 cm. The percentage depth dose with or without metal implants were compared. ResultsThe surface absorbed doses on incident plane of stainless steel plate and titanium plate were increased by 19. 6％ and 15.7％ respectively as compared water,the dose influence was less than 1.5％ more than 0. 3 cm outside the incidence plane. The doses on the exit surface of stainless steel plate and titanium plate were lowered by 8. 6％ and 8. 2％ when compared with water, the dose impacts of this places where were from the exit surface of stainless steel plate 、titanium plate more than 1.2 cm,0. 9 cm were less than 1.5％. The surface absorbed doses on incident plane of stainless steel plate were increased by 3.9％ respectively as titanium plate, the dose of the exit surface of stainless steel plate and titanium plate was similar. Conclusions MC method is a fast and accurate calculation method. The influence of metal plate on the radiotherapy dose distribution is significant. Under the such condition, the impact of stainless steel plate is much more than that of titanium alloy plate.
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Objective Due to the superior performance,Carbon-Carbon composites,although still at their early stage of development,have gained more and more attention and showed great application potential.Methods According to the National Standard,the biological safety evaluation of carbon-carbon composites were done in the following aspects:cytotoxicity test,acute systemic toxicity test,haemolysis test,pyrogen test,intramuscular implantation test.Results test results showed the biological safety evaluation of carbon-carbon composites well meet the requirement of the national standard with fine biological compatibility.Conclusion The experiment results demonstrate that carbon-carbon composites can be put in clinical application
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BACKGROUND: Fish oil is one of mainly natural resources of n-3 fatty acids, which can inhibit cardiac allograft vasculopathy (CAV) and prolong the survival of cardiac allograft. But, the mechanism is unclear. Recent in vitro data suggested that n-3 fatty acids could inhibit the release of inflammatory transmitter by the activation of peroxisome proliferator-activated receptor-y (PPARy). OBJECTIVE: To test the hypothesis that n-3 fatty acids from fish oil ameliorates CAV development via activating PPARy. METHODS: A total of 6 Lewis rats and 18 Fisher344 rats were randomly selected as heart donors. An additional 24 Lewis rats were randomly and equally divided into 4 groups. In isograft group, heart transplantation was performed among Lewis rats, without any drug. In low-dose fish oil-treated group, F344→Lewis transplantation was performed. At 1 day following surgery, 0.03 mL/kg fish oil was treated by gavage for 8 weeks. In high-dose fish oil-treated group, F344→Lewis transplantation was conducted. At 1 day following surgery, 0.06 mL/kg fish oil was treated by gavage for 8 weeks. In control group, F344→Lawis transplantation was conducted. Cyclosporine A was administrated by gavage for 8 weeks. In the low-dose and high-dose fish oil-treated groups, cyclosporine A (1.5 mg/kg) was given daily by intramuscular injection for 2 weeks following surgery. CAV was evaluated by histological examination. Activity of nuclear factor (NF) k-B and PPARy was assessed in homogenate. Contents of monocyte chemoattractant protein-1 and interferon-inducible protein 10 were measured by enzyme-labeled immunosorbent assay (ELISA). Chemokine receptor CCR2 and CXCR3 expression was determined by real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR). RESULTS AND CONCLUSION: All 24 receptor Lewis rats were survived following surgery. The donor heart could regularly beat at 8 weeks following transplantation. Compared with the isograft group, severe CAV was detected in the control group al 8 weeks. Compared with the control group, CAV was significantly relieved, the activity of PPARy was significantly elevated, the activity of NF k-B was significantly decreased, levels of intragraft monocyte chemoattractant protein-1 and interferon-inducible protein-10 were significantly reduced in the low-dose and high-dose fish oil-treated groups (P < 0.001, P < 0.05), especially in the high-dose fish oil-treated group (P < 0.05). There was no significant difference in expression of chemokine receptors CXCR3 in the low-dose and high-dose fish oil-treated groups and control group. Our results demonstrated that n-3 fatty acids from fish oil can attenuate CAV development, possibly through activating PPARy and subsequently inhibiting the NF-kB activation, the chemokines secretion and its receptor expression in a dose-dependent fashion in rat models.
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Objective: The present study aims to summarize the clinical experience in the surgical treatment of thoracic aortic dissecting aneurysm.Methods: We retrospectively analyzed the clinical data of 115 cases of thoracic aortic dissecting aneurysm treated by surgery from December 1995 to December 2006.Thirty-eight of them were DeBakey type I aortic dissection,18 type Ⅱ,and 59 type Ⅲ.Of the 38 DeBakey type I patients,30 underwent ascending aorta with total aortic arch replacement(2 cases of total thoracic aortic artificial vessel replacement,25 Wheat procedure and 3 aortic valvuloplasty) and the other 8 received ascending aorta with semi-aortic arch replacement.Of the 59 DeBakey type Ⅲ patients,36 underwent descending aortic aneurysm resection with artificial vessel replacement via left posterolateral thoracic incision by left heart bypass or aorta to artery bypass(using Cott tubes),while the other 23 received endovascular stent-graft exclusion in descending aorta via the femoral artery.Results: All the patients were successfully treated except 5 that died during the perioperative period.The survivors were followed up for 3-118 months,among whom 2 died long-term death after the operation and the others were living healthy.Conclusion: Surgical treatment improves the clinical outcome of thoracic aortic dissecting aneurysm.Bilateral perfusion via the carotid artery in aortic arch replacement has a definite cerebral protective effect.Surgical procedures can be simplified by using the modified elephant trunk technique.Endovascular stent-graft exclusion is safe and effective in the treatment of DeBakey type Ⅲ aortic dissection.
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Objectives: To study the correlation between plasma matrix metalloproteinase 9(MMP 9) concentration and acute lung injury following cardiopulmonary bypass(CPB). Methods: Human plasma was obtained after informed consent from twenty patients undergoing CPB. Plasma was collected at the beginning of CPB, 5 minutes after the initiation of CPB, at the termination of CPB, 1 hour after the termination of CPB and 6 hours after the termination of CPB. All samples were analyzed by standard enzyme linked immunosorbent assay (ELISA). A aDO 2 and respiratory index (RI) was measured at the termination, 1 hour and 6 hours after termination of CPB. The cross clamp times, CPB times and the time to extubation was recorded. Data were expressed as means ?SE and assessed by analysis of variance (ANOVA).The regression analysis was utilized to define the correlations of variables measured( A aDO 2 ,RI, cross clamp times, CPB times and the time to extubation ) at the end of CPB. Results: Plasma MMP 9 concentration was significantly increased at the end of CPB (430.6?50)?g/L( P
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Objectives:Dose-response effect of nicorandil cardioplegia at various concentrations was studied to optimize its myocardial protective effect.Methods:Forty-eight isolated working rat hearts were divided into 6 groups randomly.They were group A:control (depolarized cardiac arrest with St.Thomas solution No.2),group B,C,E,F and G:hyperpolarized cardiac arrest (nicorandil concentration were 25,50,100,125 and 150μmol/L respectively).The hearts underwent a 120-minute hypothermic arrest (15±1)℃ with cardioplegia (40 ml/kg) and reinfused with cardioplegia (40 ml/kg) at interval of 30 minutes.Mechanical arrest time,cardiac functional recoveries,myocardial content of malondialdehyde (MDA) and ultrastructure were measured.Results:The protective effect of nicorandil cardioplegia was dose-related.Conclusions:The optimal concentration of nicorandil in cardiplegia may be 100μmol/L for myocardial protection.
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Objective To investigate the effects of moderate hypothermia on the permeability of alveolar capillary membrane in acute lung injury (ALI) induced by lipopolysaccharide (LPS) .Methods Thirty-four adult male SD rats weighing 300-350g were randomly divided into 4 groups: control group (n = 8) ; LPS group (n = 10); hypothermia group (n = 8) and LPS + hypothermia group (n = 8) . The animals were anesthetized with intraperitoneal (i.p.) 1% pentobarbital 30 mg?kg-1, intubated and mechanically ventilated (RR 80 bpm, VT 20 ml?kg-1, I: E 1:2) . Right external jugular vein and left carotid artery were cannulated for BP and CVP monitoring and blood sampling. ALI was induced by LPS 1.0 mg?kg-1 i.p. and 16h later, intratracheal instillation of LPS 1.5 mg?kg-1. ALI was considered established when PaO2/FiO2 ≤300. Hypothermia was induced by surface cooling. Body T0 was reduced to 32.5-33.0℃. In control and hypothermia groups normal saline was given instead of LPS. Arterial blood samples were taken for blood gas analysis and MAP and CVP were recorded before (T0, baseline) and 1, 2, 3, 4 h after ALI (T1-4) . At the end of experiment (4h after ALI was established) the animals were killed by exsanguination. The lungs were removed. Lung lavage was performed and the concentration of albumin in bronchoalveolar lavage fluid (BALF), the left lung wet/dry weight ratio, myeloperoxidase (MPO) activity of lung tissue were measured. Lung tissue was also taken for histologic examination by transmission electron microscopy.Results There was no significant difference in hemodynamics among the 4 groups. PaO2/FiO2 and PaCO2 remained unchanged in the control group and hypothermia group. PaO2 /FiO2 was significantly decreased and PaCO2 was significantly increased as compared to the baseline values (T0) in LPS group (P
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In this study a grey model GM(1,1) was developed on the basis of malaria cases reported for the period of 1986-1990 in China. In order to further enhance the predicting power of the model,residual correction is performed and the residual correcting GM(1,1)model was established. The result showed that the predicting performance of the latter model was much improved. The number of predicted cases for 1991(101 770) was conformed to the number of actual malaria cases reported (101 636).
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AIM: To study the effect of mild hypothermia on energy metabolism and hydroxyl radical production as well as delayed neuronal death (DND) in hippocampus during cerebral ischemia/reperfusion in gerbils. METHODS: Forebrain ischemia was induced by occluding bilateral common carotid arteries with aneurysm clamps for 10 min in gerbils. The DND in hippocampal CA1 sector was assessed by histological examination, and hydroxyl radical, ATP (adenosine triphosphate), ADP (adenosine diphosphate),AMP (adenosine monophosphate) levels were determined by high performance liquid chromatography with electrochemical or ultraviolet detection. RESULTS: The number of survival neuronal in hippocampal CA1 sector in mild hypothermia + I/R group was more than that in I/R group after ischemia/reperfusion 96 h. The content of 2,3-DHBA (2,3- dihydroxybenzoic acid) in hippocampus in I/R group was much higher than those in sham operation and mild hypothermia + I/R group after reperfusion 6 h (P