297 research outputs found

    A Comparison of Two Ovine Lumbar Intervertebral Disc Injury Models for the Evaluation and Development of Novel Regenerative Therapies

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    © The Author(s) 2018. Study Design: Large animal research. Objective: Lumbar discectomy is the most commonly performed spinal surgical procedure. We investigated 2 large animal models of lumbar discectomy in order to study the regenerative capacity of mesenchymal stem cells following disc injury. Methods: Twelve adult ewes underwent baseline 3-T magnetic resonance imaging (MRI) followed by lumbar intervertebral disc injury by either drill bit (n = 6) or annulotomy and partial nucleotomy (APN) (n = 6). Necropsies were performed 6 months later. Lumbar spines underwent 3-T and 9.4-T MRI prior to histological, morphological and biochemical analysis. Results: Drill bit-injured (DBI) and APN-injured discs demonstrated increased Pfirrmann grades relative to uninjured controls (P <.005), with no difference between the 2 models. Disc height index loss was greater in the APN group compared with the DBI group (P <.005). Gross morphology injury scores were higher in APN than DBI discs (P <.05) and both were higher than controls (P <.005). Proteoglycan was reduced in the discs of both injury models relative to controls (P <.005), but lower in the APN group (P <.05). Total collagen of the APN group disc regions was higher than DBI and control discs (P <.05). Histology revealed more matrix degeneration, vascular infiltration, and granulation in the APN model. Conclusion: Although both models produced disc degeneration, the APN model better replicated the pathobiology of human discs postdiscectomy. We therefore concluded that the APN model was a more appropriate model for the investigation of the regenerative capacity of mesenchymal stem cells administered postdiscectomy

    Intentional replantation for the management of maxillary sinusitis

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    Aim. To present a case that emphasizes the importance of the use of intentional replantation as a technique to successfully treat a periapical lesion and an odontogenic maxillary sinusitis through the alveolus at the same time. Summary. This case report presents a patient with odontogenic maxillary sinusitis secondary to periapical disease of a maxillary molar that had previously received root canal treatment. The molar was extracted, with drainage and rinsing of the maxillary sinus. The apices were resected extra-orally, and the retrograde cavity was prepared with ultrasound and retrograde filling using silver amalgam. The tooth was then replanted. After 2 years, the patient was asymptomatic, periapical radiography showed no evidence of root resorption and computed tomography scanning demonstrated the resolution of maxillary sinusitis

    C-reactive protein in degenerative aortic valve stenosis

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    Degenerative aortic valve stenosis includes a range of disorder severity from mild leaflet thickening without valve obstruction, "aortic sclerosis", to severe calcified aortic stenosis. It is a slowly progressive active process of valve modification similar to atherosclerosis for cardiovascular risk factors, lipoprotein deposition, chronic inflammation, and calcification. Systemic signs of inflammation, as wall and serum C-reactive protein, similar to those found in atherosclerosis, are present in patients with degenerative aortic valve stenosis and may be expression of a common disease, useful in monitoring of stenosis progression

    Performance of the CMS Cathode Strip Chambers with Cosmic Rays

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    The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS endcaps. Their performance has been evaluated using data taken during a cosmic ray run in fall 2008. Measured noise levels are low, with the number of noisy channels well below 1%. Coordinate resolution was measured for all types of chambers, and fall in the range 47 microns to 243 microns. The efficiencies for local charged track triggers, for hit and for segments reconstruction were measured, and are above 99%. The timing resolution per layer is approximately 5 ns
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