608 research outputs found

    Outcomes of fusions from the cervical spine to the pelvis

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    A review of complications and outcomes following vertebral column resection in adults

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    The correction of rigid spinal deformities in adult patients can require a three-column osteotomy (pedicle subtraction osteotomy [PSO] or vertebral column resection [VCR]) to obtain spinal balance. Unfortunately, the existing adult deformity literature frequently reports the outcomes and complications of these procedures together even though VCR is a more extensive procedure with potentially higher rates of complications. We sought to address this shortcoming and provide clinicians with an overview of the existing literature regarding VCR in adult patients. The goals of this review are: to determine the rate of overall and neurologic complications following VCR, the rate of complications with VCR compared to PSO, and the impact of VCR on clinical and radiographic outcomes. An electronic literature search was used to identify studies reporting outcomes or complications following VCR in adult patients. Raw data on patient demographics, case information, radiographic outcomes, complications and clinical outcomes were extracted. Data were pooled to report a rate of overall complications and neurologic complications. A pooled relative risk of complications following PSO vs. VCR was also calculated. Eleven retrospective studies (Level IV) met our inclusion criteria. The overall rate of complications was 69.2%. The reoperation rate was 9.6%. The rate of neurologic complications was 13.3% (range, 6.3% to 15.8%) with most cases being transient. The rate of permanent neurologic deficits was 2.0%. We found a significantly higher rate of all complications with VCR compared to PSO (relative risk, 1.36; 95% confidence interval, 1.24–1.49; p<0.001). All studies reporting clinical outcomes showed significant improvements in functional outcome postoperatively

    Escherichia coli K1 Modulates Peroxisome Proliferator–Activated Receptor γ and Glucose Transporter 1 at the Blood-Brain Barrier in Neonatal Meningitis

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    Escherichia coli K1 meningitis continues to be a major threat to neonatal health. Previous studies demonstrated that outer membrane protein A (OmpA) of E. coli K1 interacts with endothelial cell glycoprotein 96 (Ecgp96) in the blood-brain barrier to enter the central nervous system. Here we show that the interaction between OmpA and Ecgp96 downregulates peroxisome proliferator–activated receptor γ (PPAR-γ) and glucose transporter 1 (GLUT-1) levels in human brain microvascular endothelial cells, causing disruption of barrier integrity and inhibition of glucose uptake. The suppression of PPAR-γ and GLUT-1 by the bacteria in the brain microvessels of newborn mice causes extensive pathophysiology owing to interleukin 6 production. Pretreatment with partial or selective PPAR-γ agonists ameliorate the pathological outcomes of infection by suppressing interleukin 6 production in the brain. Thus, inhibition of PPAR-γ and GLUT-1 by E. coli K1 is a novel pathogenic mechanism in meningitis, and pharmacological upregulation of PPAR-γ and GLUT-1 levels may provide novel therapeutic avenues

    An Operational Remote Sensing Algorithm of Land Surface Evaporation

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    Partitioning of solar energy at the Earth surface has significant implications in climate dynamics, hydrology, and ecology. Consequently, spatial mapping of energy partitioning from satellite remote sensing data has been an active research area for over two decades. We developed an algorithm for estimating evaporation fraction (EF), expressed as a ratio of actual evapotranspiration (ET) to the available energy (sum of ET and sensible heat flux), from satellite data. The algorithm is a simple two-source model of ET. We characterize a landscape as a mixture of bare soil and vegetation and thus we estimate EF as a mixture of EF of bare soil and EF of vegetation. In the estimation of EF of vegetation, we use the complementary relationship of the actual and the potential ET for the formulation of EF. In that, we use the canopy conductance model for describing vegetation physiology. On the other hand, we use “VI-Ts” (vegetation index-surface temperature) diagram for estimation of EF of bare soil. As operational production of EF globally is our goal, the algorithm is primarily driven by remote sensing data but flexible enough to ingest ancillary data when available. We validated EF from this prototype algorithm using NOAA/AVHRR data with actual observations of EF at AmeriFlux stations (standard error ≅ 0.17 and R2 ≅ 0.71). Global distribution of EF every 8 days will be operationally produced by this algorithm using the data of MODIS on EOS-PM (Aqua) satellite

    Cervical radiculopathy: Incidence and treatment of 1,420 consecutive cases

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    Study DesignRetrospective case series.PurposeTo determine the incidence of cervical radiculopathy requiring operative intervention by level and to report on the methods of treatment.Overview of LiteratureCervical radiculopathy is a common cause of pain and can result in progressive neurological deficits. Although the pathology is well understood, the actual incidence of cervical radiculopathy at particular spinal levels ultimately requiring operative intervention is unknown.MethodsA large consecutive series of patients operated on by a single surgeon were retrospectively analyzed. The incidence of cervical radiculopathy at each level was defined for every patient. Procedures used for operative treatment were noted. Health related quality of life (HRQL) scores were collected both pre-operatively and postoperatively.ResultsThere were 1305 primary and 115 revision operations performed. The most common primary procedures performed were anterior cervical discectomy and fusion (ACDF, 50%) and anterior cervical corpectomy and fusion (ACCF, 28%). The most commonly affected levels were C6 (66%) and C7 (62%). Reasons for revision were pseudarthrosis (27%), clinical adjacent segment pathology (CASP, 63%), persistent radiculopathy (11%), and hardware-related (2.6%). The most common procedures performed in the revision group were posterior cervical decompression and fusion (PCDF, 42%) and ACDF (40%). The most commonly affected levels were C7 (43%) and C5 (30%). Among patients that had their index surgery at our institution, the revision rate was 6.4%. In both primary and revision cases there was a significant improvement in Neck Disability Index and visual analogue scale scores postoperatively. Postoperative HRQL scores in the revision cases were significantly worse than those in the primary cases (p <0.01).ConclusionsThis study provides the largest description of the incidence of cervical radiculopathy by level and operative outcomes in patients undergoing cervical decompression. The incidence of CASP was 4.2% in 3.3 years in this single institution series

    COL4A3 expression in asthmatic epithelium depends on intronic methylation and ZNF263 binding.

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    Background: Reduction of COL4A3, one of the six isoforms of collagen 4, in asthmatic airways results in increased inflammation and angiogenesis, implicating it as a central part of asthma pathogenesis. However, to date, the path underlying these diminished COL4A3 levels has been elusive. This study investigated a possible mechanism underlying the reduction of COL4A3 expression. Methods: Bronchial biopsies of 76 patients with asthma and 83 controls were subjected to RNA-sequencing and DNA methylation bead arrays to identify expression and methylation changes. The binding of ZNF263 was analysed by chromatin-immunoprecipitation sequencing coupled with quantitative (q)PCR. Effects of ZNF263 silencing, using small interfering RNA, on the COL4A3 expression were studied using qPCR. Results: COL4A3 expression was significantly reduced in bronchial biopsies compared to healthy controls, whereas DNA methylation levels at cg11797365 were increased. COL4A3 expression levels were significantly low in asthmatics without inhaled corticosteroid (ICS) use, whereas the expression was not statistically different between asthmatics using ICS and controls. Methylation levels at cg11797365 in vitro were increased upon consecutive rhinovirus infections. Conclusion: Our data indicate an epigenetic modification as a contributing factor for the loss of COL4A3 expression in asthmatic airway epithelium

    Open-String Actions and Noncommutativity Beyond the Large-B Limit

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    In the limit of large, constant B-field (the ``Seiberg-Witten limit''), the derivative expansion for open-superstring effective actions is naturally expressed in terms of the symmetric products *n. Here, we investigate corrections around the large-B limit, for Chern-Simons couplings on the brane and to quadratic order in gauge fields. We perform a boundary-state computation in the commutative theory, and compare it with the corresponding computation on the noncommutative side. These results are then used to examine the possible role of Wilson lines beyond the Seiberg-Witten limit. To quadratic order in fields, the entire tree-level amplitude is described by a metric-dependent deformation of the *2 product, which can be interpreted in terms of a deformed (non-associative) version of the Moyal * product.Comment: 30 pages, harvma

    Outcomes of Fusions From the Cervical Spine to the Pelvis.

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    Study designRetrospective cohort study.ObjectiveDetermine the indications, complications, and clinical outcomes in patients requiring fusions from the cervical spine to the pelvis. Several investigators have examined fusions from the thoracic spine to the sacrum, but no similar study has been performed for cervical-to-pelvis fusions.MethodsPatients from 2003 to 2014 with an upper instrumented vertebrae (UIV) in the cervical spine (any level) and a lower instrumented vertebrae (LIV) in the sacrum or pelvis were included in the study. Those with infectious or acute trauma-related deformities were excluded. Patient demographics, medical history, diagnosis, operative procedure, and health-related quality of life measures were analyzed. Student's t test, Kruskal-Wallis test, and χ2 test were used as appropriate; significance was set at P &lt; .05 for all tests.ResultsFifty-five patients met inclusion criteria for the study. Average follow-up was 2.8 years. Proximal junctional kyphosis was the most common indication for cervical-to-pelvis fusions (36%). The most common UIV was C2 (29%) followed by C7 (24%). There was an average 31° correction in maximum kyphosis and a 3.3 cm improvement in sagittal vertical axis. In adults, the rate of complication was 71.4%, with a major complication rate of 39.3% and reoperation rate of 53.6%. There was significant improvement in the Scoliosis Research Society (SRS-22r) score (3.0 to 3.5; P &lt; .01).ConclusionProximal junctional kyphosis is the most common indication for patients requiring fusion to the cervical spine. Adult patients incur a significant risk of major complications and reoperations. However, significant improvement in SRS-22r outcomes are noted in these patients
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