The temporal expression of microRNA after spinal cord ischemia/reperfusion injury is not yet fully understood. In the present study, we established a model of spinal cord ischemia in Sprague-Dawley rats by clamping th...The temporal expression of microRNA after spinal cord ischemia/reperfusion injury is not yet fully understood. In the present study, we established a model of spinal cord ischemia in Sprague-Dawley rats by clamping the abdominal aorta for 90 minutes, before allowing reperfusion for 24 or 48 hours. A sham-operated group underwent surgery but the aorta was not clamped. The damaged spinal cord was removed for hematoxylin-eosin staining and RNA extraction. Neuronal degeneration and tissue edema were the most severe in the 24- hour reperfusion group, and milder in the 48-hour reperfusion group. RNA amplification, labeling, and hybridization were used to obtain the microRNA expression profiles of each group. Bioinformatics analysis confirmed tour differentially expressed microRNAs （miR-22-3p, miR-743b-3p, miR-201-5p and miR-144-5p） and their common target genes （Tmem69 and Cxcll0）. Compared with the sham group, miR- 22-3p was continuously upregulated in all three ischemia groups but was highest in the group with 11o reperfusion, whereas miR-743b-3p, miR-201-5p and miR-144-5p were downregulated in the three ischemia groups. We have successfully identified the key genes expressed at different stages of spinal cord ischemia/reperfusion injury, which provide a reference for future investigations into the mechanism of spinal cord injury.展开更多
Following spinal cord ischemia/reperfusion injury,an endogenous damage system is immediately activated and participates in a cascade reaction.It is difficult to interpret dynamic changes in these pathways,but the exam...Following spinal cord ischemia/reperfusion injury,an endogenous damage system is immediately activated and participates in a cascade reaction.It is difficult to interpret dynamic changes in these pathways,but the examination of the transcriptome may provide some information.The transcriptome reflects highly dynamic genomic and genetic information and can be seen as a precursor for the proteome.We used DNA microarrays to measure the expression levels of dynamic evolution-related m RNA after spinal cord ischemia/reperfusion injury in rats.The abdominal aorta was blocked with a vascular clamp for 90 minutes and underwent reperfusion for 24 and 48 hours.The simple ischemia group and sham group served as controls.After rats had regained consciousness,hindlimbs showed varying degrees of functional impairment,and gradually improved with prolonged reperfusion in spinal cord ischemia/reperfusion injury groups.Hematoxylin-eosin staining demonstrated that neuronal injury and tissue edema were most severe in the 24-hour reperfusion group,and mitigated in the 48-hour reperfusion group.There were 8,242 differentially expressed m RNAs obtained by Multi-Class Dif in the simple ischemia group,24-hour and 48-hour reperfusion groups.Sixteen m RNA dynamic expression patterns were obtained by Serial Test Cluster.Of them,five patterns were significant.In the No.28 pattern,all differential genes were detected in the 24-hour reperfusion group,and their expressions showed a trend in up-regulation.No.11 pattern showed a decreasing trend in m RNA whereas No.40 pattern showed an increasing trend in m RNA from ischemia to 48 hours of reperfusion,and peaked at 48 hours.In the No.25 and No.27 patterns,differential expression appeared only in the 24-hour and 48-hour reperfusion groups.Among the five m RNA dynamic expression patterns,No.11 and No.40 patterns could distinguish normal spinal cord from pathological tissue.No.25 and No.27 patterns could distinguish simple ischemia from ischemia/reperfusion.No.28 pattern could analyze the need for inducing reperfusion injury.The study of specific pathways and functions for different dynamic patterns can provide a theoretical basis for clinical differential diagnosis and treatment of spinal cord ischemia/reperfusion injury.展开更多
This paper presents a novel wideband fast multipole boundary element approach to 3D half-space/planesymmetric acoustic wave problems.The half-space fundamental solution is employed in the boundary integral equations s...This paper presents a novel wideband fast multipole boundary element approach to 3D half-space/planesymmetric acoustic wave problems.The half-space fundamental solution is employed in the boundary integral equations so that the tree structure required in the fast multipole algorithm is constructed for the boundary elements in the real domain only.Moreover,a set of symmetric relations between the multipole expansion coefficients of the real and image domains are derived,and the half-space fundamental solution is modified for the purpose of applying such relations to avoid calculating,translating and saving the multipole/local expansion coefficients of the image domain.The wideband adaptive multilevel fast multipole algorithm associated with the iterative solver GMRES is employed so that the present method is accurate and efficient for both lowand high-frequency acoustic wave problems.As for exterior acoustic problems,the Burton-Miller method is adopted to tackle the fictitious eigenfrequency problem involved in the conventional boundary integral equation method.Details on the implementation of the present method are described,and numerical examples are given to demonstrate its accuracy and efficiency.展开更多
基金supported by a Grant from the National Natural Science Foundation of China,No.81350013,31572217,and 81672263
文摘The temporal expression of microRNA after spinal cord ischemia/reperfusion injury is not yet fully understood. In the present study, we established a model of spinal cord ischemia in Sprague-Dawley rats by clamping the abdominal aorta for 90 minutes, before allowing reperfusion for 24 or 48 hours. A sham-operated group underwent surgery but the aorta was not clamped. The damaged spinal cord was removed for hematoxylin-eosin staining and RNA extraction. Neuronal degeneration and tissue edema were the most severe in the 24- hour reperfusion group, and milder in the 48-hour reperfusion group. RNA amplification, labeling, and hybridization were used to obtain the microRNA expression profiles of each group. Bioinformatics analysis confirmed tour differentially expressed microRNAs （miR-22-3p, miR-743b-3p, miR-201-5p and miR-144-5p） and their common target genes （Tmem69 and Cxcll0）. Compared with the sham group, miR- 22-3p was continuously upregulated in all three ischemia groups but was highest in the group with 11o reperfusion, whereas miR-743b-3p, miR-201-5p and miR-144-5p were downregulated in the three ischemia groups. We have successfully identified the key genes expressed at different stages of spinal cord ischemia/reperfusion injury, which provide a reference for future investigations into the mechanism of spinal cord injury.
基金supported by the National Natural Science Foundation of China,No.81350013 and 31572217
文摘Following spinal cord ischemia/reperfusion injury,an endogenous damage system is immediately activated and participates in a cascade reaction.It is difficult to interpret dynamic changes in these pathways,but the examination of the transcriptome may provide some information.The transcriptome reflects highly dynamic genomic and genetic information and can be seen as a precursor for the proteome.We used DNA microarrays to measure the expression levels of dynamic evolution-related m RNA after spinal cord ischemia/reperfusion injury in rats.The abdominal aorta was blocked with a vascular clamp for 90 minutes and underwent reperfusion for 24 and 48 hours.The simple ischemia group and sham group served as controls.After rats had regained consciousness,hindlimbs showed varying degrees of functional impairment,and gradually improved with prolonged reperfusion in spinal cord ischemia/reperfusion injury groups.Hematoxylin-eosin staining demonstrated that neuronal injury and tissue edema were most severe in the 24-hour reperfusion group,and mitigated in the 48-hour reperfusion group.There were 8,242 differentially expressed m RNAs obtained by Multi-Class Dif in the simple ischemia group,24-hour and 48-hour reperfusion groups.Sixteen m RNA dynamic expression patterns were obtained by Serial Test Cluster.Of them,five patterns were significant.In the No.28 pattern,all differential genes were detected in the 24-hour reperfusion group,and their expressions showed a trend in up-regulation.No.11 pattern showed a decreasing trend in m RNA whereas No.40 pattern showed an increasing trend in m RNA from ischemia to 48 hours of reperfusion,and peaked at 48 hours.In the No.25 and No.27 patterns,differential expression appeared only in the 24-hour and 48-hour reperfusion groups.Among the five m RNA dynamic expression patterns,No.11 and No.40 patterns could distinguish normal spinal cord from pathological tissue.No.25 and No.27 patterns could distinguish simple ischemia from ischemia/reperfusion.No.28 pattern could analyze the need for inducing reperfusion injury.The study of specific pathways and functions for different dynamic patterns can provide a theoretical basis for clinical differential diagnosis and treatment of spinal cord ischemia/reperfusion injury.
基金supported by the National Natural Science Foundation of China (11172291)the National Science Foundation for Post-doctoral Scientists of China (2012M510162)the Fundamental Research Funds for the Central Universities (KB2090050024)
文摘This paper presents a novel wideband fast multipole boundary element approach to 3D half-space/planesymmetric acoustic wave problems.The half-space fundamental solution is employed in the boundary integral equations so that the tree structure required in the fast multipole algorithm is constructed for the boundary elements in the real domain only.Moreover,a set of symmetric relations between the multipole expansion coefficients of the real and image domains are derived,and the half-space fundamental solution is modified for the purpose of applying such relations to avoid calculating,translating and saving the multipole/local expansion coefficients of the image domain.The wideband adaptive multilevel fast multipole algorithm associated with the iterative solver GMRES is employed so that the present method is accurate and efficient for both lowand high-frequency acoustic wave problems.As for exterior acoustic problems,the Burton-Miller method is adopted to tackle the fictitious eigenfrequency problem involved in the conventional boundary integral equation method.Details on the implementation of the present method are described,and numerical examples are given to demonstrate its accuracy and efficiency.
