Glial cells in the central nervous system （CNS） contribute to formation of the extracellular matrix, which provides adhesive sites, signaling molecules, and a diffusion barrier to enhance efficient on and axon poten...Glial cells in the central nervous system （CNS） contribute to formation of the extracellular matrix, which provides adhesive sites, signaling molecules, and a diffusion barrier to enhance efficient on and axon potential propagation. In the normal adult CNS, the extracellular matrix （ECM） is relatively stable except in selected regions characterized by dynamic remodeling. However, after trauma such as a spinal cord injury or cortical contusion, the lesion epicenter becomes a focus of acute neuroinflammation. The activation of the surrounding glial cells leads to a dramatic change in the composition of the ECM at the edges of the lesion, creating a perilesion environment dominated by growth inhibitory molecules and restoration of the peripheral/ central nervous system border. An advantage of this response is to limit the invasion of damaging cells and diffusion of toxic molecules into the spared tissue regions, but this occurs at the cost of inhibiting migration of endogenous repair cells and preventing axonal regrowth. The following review was prepared by reading and discussing over 200 research articles in the field published in PubMed and selecting those with significant impact and/or controversial points. This article highlights structural and functional features of the normal adult CNS ECM and then focuses on the reactions of glial cells and changes in the perilesion border that occur following spinal cord or contusive brain injury. Current research strategies directed at modifying the inhibitory perilesion microenvironment without eliminating the protective functions of glial cell activation are discussed.展开更多
We conducted a cross-sectional study to establish the effect of proximity of livestock to a wildlife-livestock interface on the relative abundance of intra-erythrocytic hemoparasites in cattle. Blood samples were obta...We conducted a cross-sectional study to establish the effect of proximity of livestock to a wildlife-livestock interface on the relative abundance of intra-erythrocytic hemoparasites in cattle. Blood samples were obtained from 131 randomlyselected cattle raised around Queen Elizabeth National Park. Cattle-farm location was determined by using Global Positioning System device from an arbitrarily reference point. Giemsa-stained blood smears were examined microscopically for intra-erythrocytic hemoparasites. Correlational analysis was used to examine the relationship between farm location and prevalence, whereas risk ratios were used to determine the strength of mixed hemoparasitic infections among cattle, using a significant level of α = 0.05. The location of a cattle farm significantly predicted the prevalence of Anaplasma (rs = 0.33, p 0.05) and Theileria (rs = 0.57, p 0.01) but, farm’s proximity to QENP did not explain the variation in the prevalence of Babesia (rs = 0.14, p 0.2). Although mixed infections occurred in 15% of sampled cattle, concurrent infection of cattle with A. marginale and B. bigemina [RR = 36;95% CI (7.191);p which was recorded. This study demonstrated that unlike the prevalence of B. bigemina, the prevalence of T. parva and A. marginale in livestock significantly increased with close proximity to a wildlife-livestock interface.展开更多
基金supported by NIH/NINDS R01-NS043246,P30-NS045758,the International Spinal Research Trust(STR-100)the Ohio State University College of Medicine
文摘Glial cells in the central nervous system （CNS） contribute to formation of the extracellular matrix, which provides adhesive sites, signaling molecules, and a diffusion barrier to enhance efficient on and axon potential propagation. In the normal adult CNS, the extracellular matrix （ECM） is relatively stable except in selected regions characterized by dynamic remodeling. However, after trauma such as a spinal cord injury or cortical contusion, the lesion epicenter becomes a focus of acute neuroinflammation. The activation of the surrounding glial cells leads to a dramatic change in the composition of the ECM at the edges of the lesion, creating a perilesion environment dominated by growth inhibitory molecules and restoration of the peripheral/ central nervous system border. An advantage of this response is to limit the invasion of damaging cells and diffusion of toxic molecules into the spared tissue regions, but this occurs at the cost of inhibiting migration of endogenous repair cells and preventing axonal regrowth. The following review was prepared by reading and discussing over 200 research articles in the field published in PubMed and selecting those with significant impact and/or controversial points. This article highlights structural and functional features of the normal adult CNS ECM and then focuses on the reactions of glial cells and changes in the perilesion border that occur following spinal cord or contusive brain injury. Current research strategies directed at modifying the inhibitory perilesion microenvironment without eliminating the protective functions of glial cell activation are discussed.
文摘We conducted a cross-sectional study to establish the effect of proximity of livestock to a wildlife-livestock interface on the relative abundance of intra-erythrocytic hemoparasites in cattle. Blood samples were obtained from 131 randomlyselected cattle raised around Queen Elizabeth National Park. Cattle-farm location was determined by using Global Positioning System device from an arbitrarily reference point. Giemsa-stained blood smears were examined microscopically for intra-erythrocytic hemoparasites. Correlational analysis was used to examine the relationship between farm location and prevalence, whereas risk ratios were used to determine the strength of mixed hemoparasitic infections among cattle, using a significant level of α = 0.05. The location of a cattle farm significantly predicted the prevalence of Anaplasma (rs = 0.33, p 0.05) and Theileria (rs = 0.57, p 0.01) but, farm’s proximity to QENP did not explain the variation in the prevalence of Babesia (rs = 0.14, p 0.2). Although mixed infections occurred in 15% of sampled cattle, concurrent infection of cattle with A. marginale and B. bigemina [RR = 36;95% CI (7.191);p which was recorded. This study demonstrated that unlike the prevalence of B. bigemina, the prevalence of T. parva and A. marginale in livestock significantly increased with close proximity to a wildlife-livestock interface.
