26 research outputs found

    Human Brain Microvascular Endothelial Cells and Umbilical Vein Endothelial Cells Differentially Facilitate Leukocyte Recruitment and Utilize Chemokines for T Cell Migration

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    Endothelial cells that functionally express blood brain barrier (BBB) properties are useful surrogates for studying leukocyte-endothelial cell interactions at the BBB. In this study, we compared two different endothelial cellular models: transfected human brain microvascular endothelial cells (THBMECs) and human umbilical vein endothelial cells (HUVECs). With each grow under optimal conditions, confluent THBMEC cultures showed continuous occludin and ZO-1 immunoreactivity, while HUVEC cultures exhibited punctate ZO-1 expression at sites of cell-cell contact only. Confluent THBMEC cultures on 24-well collagen-coated transwell inserts had significantly higher transendothelial electrical resistance (TEER) and lower solute permeability than HUVECs. Confluent THBMECs were more restrictive for mononuclear cell migration than HUVECs. Only THBMECs utilized abluminal CCL5 to facilitate T-lymphocyte migration in vitro although both THBMECs and HUVECs employed CCL3 to facilitate T cell migration. These data establish baseline conditions for using THBMECs to develop in vitro BBB models for studying leukocyte-endothelial interactions during neuroinflammation

    Robust estimation of bacterial cell count from optical density

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    Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

    Do personality traits, perceived benefits and costs, and network externality affect consumers' adoption of 3G services?

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    To determine whether Impulse Buying Tendency, Optimum Stimulation Level, Creativity, Perceived Benefits and Costs, and Network Externality will affect adoption of technology, using 3G for the emphirical study of our framework

    Is peripheral immunity regulated by blood-brain barrier permeability changes?

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    S100B is a reporter of blood-brain barrier (BBB) integrity which appears in blood when the BBB is breached. Circulating S100B derives from either extracranial sources or release into circulation by normal fluctuations in BBB integrity or pathologic BBB disruption (BBBD). Elevated S100B matches the clinical presence of indices of BBBD (gadolinium enhancement or albumin coefficient). After repeated sub-concussive episodes, serum S100B triggers an antigen-driven production of anti-S100B autoantibodies. We tested the hypothesis that the presence of S100B in extracranial tissue is due to peripheral cellular uptake of serum S100B by antigen presenting cells, which may induce the production of auto antibodies against S100B. To test this hypothesis, we used animal models of seizures, enrolled patients undergoing repeated BBBD, and collected serum samples from epileptic patients. We employed a broad array of techniques, including immunohistochemistry, RNA analysis, tracer injection and serum analysis. mRNA for S100B was segregated to barrier organs (testis, kidney and brain) but S100B protein was detected in immunocompetent cells in spleen, thymus and lymph nodes, in resident immune cells (Langerhans, satellite cells in heart muscle, etc.) and BBB endothelium. Uptake of labeled S100B by rat spleen CD4+ or CD8+ and CD86+ dendritic cells was exacerbated by pilocarpine-induced status epilepticus which is accompanied by BBBD. Clinical seizures were preceded by a surge of serum S100B. In patients undergoing repeated therapeutic BBBD, an autoimmune response against S100B was measured. In addition to its role in the central nervous system and its diagnostic value as a BBBD reporter, S100B may integrate blood-brain barrier disruption to the control of systemic immunity by a mechanism involving the activation of immune cells. We propose a scenario where extravasated S100B may trigger a pathologic autoimmune reaction linking systemic and CNS immune responses

    Comparison of Acute Ischemic Stroke Care and Outcomes Between Comprehensive Stroke Centers and Primary Stroke Centers in the United States

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    BackgroundTo improve stroke care, the Brain Attack Coalition recommended establishing primary stroke center (PSC) and comprehensive stroke center (CSC) certification. This study aimed to compare ischemic stroke care and in-hospital outcomes between CSCs and PSCs.Methods and resultsWe analyzed patients with acute ischemic stroke who were hospitalized at stroke centers participating in Get With The Guidelines-Stroke from 2013 to 2015. Multivariable logistic regression models were generated to examine the association between stroke center certification (CSC versus PSC) and performances and outcomes. This study included 722 941 patients who were admitted to 134 CSCs and 1047 PSCs. Both CSCs and PSCs had good conformity to 7 performance measures and the summary defect-free care measure. Among emergency department admissions, CSCs had higher intravenous tPA (tissue-type plasminogen activator) and endovascular thrombectomy rates than PSCs (14.3% versus 10.3%, 4.1% versus 1.0%, respectively). Door to intravenous tPA time was shorter at CSCs (median, 52 versus 61 minutes; adjusted risk ratio, 0.92; 95% confidence interval, 0.89-0.95). More patients at CSCs had door to intravenous tPA time ≤60 minutes (79.7% versus 65.1%; adjusted odds ratio, 1.48; 95% confidence interval, 1.25-1.75). For transferred patients, CSCs and PSCs had comparable overall performance in defect-free care, except higher endovascular thrombectomy therapy rates. The overall in-hospital mortality was higher at CSCs in both emergency department admissions (4.6% versus 3.8%; adjusted odds ratio, 1.14; 95% confidence interval, 1.01-1.29) and transferred patients (7.7% versus 6.8%; adjusted odds ratio, 1.17; 95% confidence interval, 1.05-1.32). In-hospital outcomes were comparable between CSCs and PSCs in patients who received intravenous tPA or endovascular thrombectomy.ConclusionsCSCs and PSCs achieved similar overall care quality for patients with acute ischemic stroke. CSCs exceeded PSCs in timely acute reperfusion therapy for emergency department admissions, whereas PSCs had lower risk-adjusted in-hospital mortality. This information may be important for acute stroke triage and targeted quality improvement

    High‐dose Methotrexate plus temozolomide with or without rituximab in patients with untreated primary central nervous system lymphoma: A retrospective study from China

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    Abstract The purpose of this retrospective study was to compare the efficacy and toxicity of high‐dose methotrexate plus temozolomide (MT regimen) and rituximab plus MT (RMT regimen) in patients with untreated primary central nervous system lymphoma (PCNSL). A total of 62 patients with untreated PCNSL were enrolled between January 2005 and December 2015, with the median age of 53.5 years (range 29‐77).In this study, 32 patients received RMT as induction therapy, and 30 received MT. Objective responses were noted in 93.7% of the patients in the RMT group and in 69.0% of the patients in the MT group (P = 0.018), while complete responses were noted in 53.2% of the patients in the RMT group and 27.6% of the patients in the MT group (P < 0.001). The 2‐ and 5‐year PFS rates were 81.3% and 53.3%, respectively, for the RMT group and 46.5% and 29.1%, respectively, for the MT group (P = 0.019). The 2‐ and 5‐year overall survival (OS) rates were 82.3% and 82.3%, respectively, for the RMT group and 65.7% and 50.0%, respectively, for the MT group (P = 0.015). Multivariate analyses showed that therapeutic regimen (RMT vs MT) was an independent prognostic factor for PFS and OS. Our encouraging results suggest that the RMT regimen may be a feasible and safe therapeutic approach for first‐line treatment of PCNSL
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