Evaluation of a novel quantitative canine species-specific point-of-care assay for C-reactive protein

Background: Species-specific point-of-care tests (POCT) permit a rapid analysis of canine C-reactive protein (CRP), enabling veterinarians to include CRP in clinical decisions. Aim of the study was to evaluate a novel POCT for canine CRP (Point Stripâ TM Canine CRP Assay) run on a small in-house-analyzer (Point Reader TM V) using lithium heparin plasma and to compare assay performance to an already established canine CRP assay (Gentian Canine CRP Immunoassay) run on two different bench top analyzers serving as reference methods (ABX Pentra 400, AU 5800). Linearity was assessed by stepwise dilution of plasma samples with high CRP concentrations. Limit of quantification (LoQ) was determined by repeated measurements of samples with low CRP concentrations. Coefficient of variation (CV) at low (10-50 mg/l), moderate (50-100 mg/l), and high (100-200 mg/l) CRP concentrations was investigated as well as possible interferences. Method comparison study was performed using 45 samples of healthy and diseased dogs. Quality criteria were fulfilled if the total observed error (TEobs=2CV%+bias%) was below the minimal total allowable error of 44.4% (TE min). Additionally, a reference range (n =60 healthy dogs) was established. Results: Linearity was present at CRP concentrations of 10-132 mg/l (&#8793; 361 mg/l CRP with reference method) with a LoQ set at 10 mg/l. At moderate to high CRP concentrations, intra- and inter-assay CVs were< =8% and <=11% respectively, while CVs<=22% and <=28% were present at low concentrations. No interferences were observed at concentrations of 4 g/l hemoglobin, 800 mg/l bilirubin and 8 g/l triglycerides. Method comparison study demonstrated an excellent correlation with both reference methods (r =0.98 for ABX Pentra 400; 0.99 for AU 5800), though revealing a proportional bias of 19.7% (ABX Pentra 400) and 10.7% (AU 5800) respectively. TEobs was 26.7-31.9% and 16.7-21.9% and thus < TEmin. Healthy dogs presented with CRP values <=11.9 mg/l. Conclusions The POCT precisely detects canine CRP at clinically relevant moderate and high CRP concentrations. The assay correlates well with both reference methods. Due to the bias, however, follow-up examinations should be performed with the same assay and analyzer

The magnetic reversal in dot arrays recognized by the self-organized adaptive neural network

The remagnetization dynamics of monolayer dot array superlattice XY 2-D spin model with dipole-dipole interactions is simulated. Within the proposed model of array, the square dots are described by the spatially modulated exchange-couplings. The dipole-dipole interactions are approximated by the hierarchical sums and spin dynamics is considered in regime of the Landau-Lifshitz equation. The simulation of reversal for $40 000$ spins exhibits formation of nonuniform intra-dot configurations with nonlinear wave/anti-wave pairs developed at intra-dot and inter-dot scales. Several geometric and parametric dependences are calculated and compared with oversimplified four-spin model of reversal. The role of initial conditions and the occurrence of coherent rotation mode is also investigated. The emphasis is on the classification of intra-dot or inter-dot (interfacial) magnetic configurations done by adaptive neural network with varying number of neurons.Comment: 16 figure

Prospective Comparative Quality Control Study of a Novel Gravity-Driven Hollow-Fiber Whole Blood Separation System for the Production of Canine Blood Products

The aim of this prospective study was to compare quality of blood products produced either by a novel gravity-driven hollow-fiber separation system (HF) or by centrifugation (C). Whole blood was obtained from 31 healthy non-greyhound canine blood donors and separated into fresh frozen plasma and packed red blood cells using either HF or C in a university teaching hospital. Red blood cell (RBC) count, albumin and fibrinogen concentration, prothrombin time (PT), activated partial thromboplastin time (aPTT) and coagulation factor activity (FV, FVIII), von Willebrand Factor (vWF), and antithrombin activity were assessed. Plasma obtained with the HF showed a significantly higher median PT (9.4 vs. 7.9 s, P = 0.0006) and aPTT (14.9 vs. 13.1 s, P = 0.0128) than plasma prepared with C. Lower albumin (21.7 vs. 23.5 g/l, P = 0.0162) and fibrinogen (1.0 vs. 1.5 g/l, P = 0.0005) concentrations and activities of FV (105 vs. 114%, P = 0.0021) and antithrombin (104 vs. 117%, P = 0.0024) were seen in blood products obtained with the HF. In contrast, vWF was not affected by the method of plasma separation. Compared to HF, RBC count as well as hematocrit were not significantly higher (8.0 vs. 8.9 1012/l, P = 0.1308; 0.57 vs. 0.62 l/l, P = 0.0736) when blood products were prepared with C. In conclusion, higher quality of blood products especially regarding coagulation parameters and RBCs was achieved by using C compared to HF. Despite the statistical significances, however, the clinical relevance has to be further elucidated. Nevertheless, HF provides an alternative to produce blood products if a centrifuge is not available

Performance of the CMS Cathode Strip Chambers with Cosmic Rays

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

Performance and Operation of the CMS Electromagnetic Calorimeter

The operation and general performance of the CMS electromagnetic calorimeter using cosmic-ray muons are described. These muons were recorded after the closure of the CMS detector in late 2008. The calorimeter is made of lead tungstate crystals and the overall status of the 75848 channels corresponding to the barrel and endcap detectors is reported. The stability of crucial operational parameters, such as high voltage, temperature and electronic noise, is summarised and the performance of the light monitoring system is presented

CREB Inhibits AP-2α Expression to Regulate the Malignant Phenotype of Melanoma

The loss of AP-2alpha and increased activity of cAMP-responsive element binding (CREB) protein are two hallmarks of malignant progression of cutaneous melanoma. However, the molecular mechanism responsible for the loss of AP-2alpha during melanoma progression remains unknown.Herein, we demonstrate that both inhibition of PKA-dependent CREB phosphorylation, as well as silencing of CREB expression by shRNA, restored AP-2alpha protein expression in two metastatic melanoma cell lines. Moreover, rescue of CREB expression in CREB-silenced cell lines downregulates expression of AP-2alpha. Loss of AP-2alpha expression in metastatic melanoma occurs via a dual mechanism involving binding of CREB to the AP-2alpha promoter and CREB-induced overexpression of another oncogenic transcription factor, E2F-1. Upregulation of AP-2alpha expression following CREB silencing increases endogenous p21(Waf1) and decreases MCAM/MUC18, both known to be downstream target genes of AP-2alpha involved in melanoma progression.Since AP-2alpha regulates several genes associated with the metastatic potential of melanoma including c-KIT, VEGF, PAR-1, MCAM/MUC18, and p21(Waf1), our data identified CREB as a major regulator of the malignant melanoma phenotype