284 resultados para Regeneration. Howell-Jolly Body


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Previous studies have shown that following whole-body irradiation bone marrow (BM)-derived cells can migrate into the central nervous system, including the retina, to give rise to microglia-like cells. The detailed mechanism, however, remains elusive. We show in this study that a single-dose whole-body ?-ray irradiation (8 Gy) induced subclinical damage (i.e., DNA damage) in the neuronal retina, which is accompanied by a low-grade chronic inflammation, para-inflammation, characterized by upregulated expression of chemokines (CCL2, CXCL12, and CX3CL1) and complement components (C4 and CFH), and microglial activation. The upregulation of chemokines CCL2 and CXCL12 and complement C4 lasted for more than 160 days, whereas the expression of CX3CL1 and CFH was upregulated for 2 weeks. Both resident microglia and BM-derived phagocytes displayed mild activation in the neuronal retina following irradiation. When BM cells from CX3CR1gfp/+ mice or CX3CR1gfp/gfp mice were transplanted to wild-type C57BL/6 mice, more than 90% of resident CD11b+ cells were replaced by donor-derived GFP+ cells after 6 months. However, when transplanting CX3CR1gfp/+ BM cells into CCL2-deficient mice, only 20% of retinal CD11b+ cells were replaced by donor-derived cells at 6 month. Our results suggest that the neuronal retina suffers from a chronic stress following whole-body irradiation, and a para-inflammatory response is initiated, presumably to rectify the insults and maintain homeostasis. The recruitment of BM-derived myeloid cells is a part of the para-inflammatory response and is CCL2 but not CX3CL1 dependent. © 2012 Wiley Periodicals, Inc.

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Q fever is caused by Coxiella burnetii and often has an insidious clinical presentation. We describe a rare case of Q fever infection of an aortic graft presenting with pyrexia and constant severe midlumbar pain due to erosion of multiple vertebral bodies. After successful treatment with graft resection and extra-anatomic vascular reconstruction, the patient continues on lifelong antibiotic therapy. We also present regional Q fever epidemiologic data together with a review of all previously documented cases of Q fever infections of vascular prostheses.

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In practice, polyvinyl chloride endotracheal tubes and polyurethane urinary catheters are located in areas where they are exposed to the conditioning fluids saliva and urine, respectively. Samples of both biomaterials were incubated in these conditioning fluids and, following treatment, dynamic contact angle measurement and surface roughness assessment by atomic force microscopy were used to analyse surface characteristics. Over a 24 h period of contact with the conditioning fluids, the surface of both materials became significantly more hydrophilic (p

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In the present study of Dugesia tigrina the development of the nervous system is followed and compared during regeneration after fission and after decapitation. Immunocytochemistry was used, with antisera raised against the biogenic amine, 5-hydroxytryptamine (5-HT) and the two neuropeptides, neuropeptide F (NPF), and FMRF amide. The results indicate that two processes are involved in the formation of the new cerebral ganglion. First, new processes sprouting from the original main longitudinal nerve cords bend transversely, indicating the position of the developing horseshoe-shaped anterior cerebral commissure. Then new nerve cells in front of the commissure differentiate from neoblasts and their growth cones fasciculate with the fibres from the old main longitudinal nerve cords. In the cerebral ganglion, 5-HT-IR cells appear before NPF-IR cells, in contrast to the pharynx where NPF-IR cells differentiate before the 5-HT-IR cells. In the peripheral nervous system, NPF-IR fibres and cells appear at a very early stage and dominate the whole regeneration process. A role for the PNS in early pattern formation is suggested.