1,040 research outputs found
Nucleosomes in serum as a marker for cell death
The concentration of nucleosomes is elevated in blood of patients with diseases which are associated with enhanced cell death. In order to detect these circulating nucleosomes, we used the Cell Death Detection-ELISA(Plus) (CDDE) from Roche Diagnostics (Mannheim, Germany) (details at http:\textbackslash{}\textbackslash{}biochem.roche.com). For its application in liquid materials we performed various modifications: we introduced a standard curve with nucleosome-rich material, which enabled direct quantification and improved comparability of the values within (CVinterassay:3.0-4.1%) and between several runs (CVinterassay:8.6-13.5%), and tested the analytical specificity of the ELISA. Because of the fast elimination of nucleosomes from circulation and their limited stability, we compared plasma and serum matrix and investigated in detail the pre-analytical handling of serum samples which can considerably influence the test results. Careless venipuncture producing hemolysis, delayed centrifugation and bacterial contamination of the blood samples led to false-positive results; delayed stabilization with EDTA and insufficient storage conditions resulted in false-negative values. At temperatures of -20 degreesC, serum samples which were treated with 10 mM EDTA were stable for at least 6 months. In order to avoid possible interfering factors, we recommend a schedule for the pre-analytical handling of the samples. As the first stage, the possible clinical application was investigated in the sera of 310 persons. Patients with solid tumors (n = 220; mean = 361 Arbitrary Units (AU)) had considerably higher values than healthy persons (n = 50; mean = 30 AU; P = 0.0001) and patients with inflammatory diseases (n = 40; mean = 296 AU; p = 0.096). Within the group of patients with tumors, those in advanced stages (UICC 4) showed significantly higher values than those in early stages (UICC 1-3) (P = 0.0004)
Long-term safety data from the cladribine tablets clinical development program in multiple sclerosis
Background: Long-term safety data are of particular interest for any newly approved treatment in multiple sclerosis such as cladribine tablets 10 mg (MAVENCLAD®; 3.5 mg/kg cumulative dose over 2 years, referred to as cladribine tablets 3.5 mg/kg), which is approved in Europe and the USA. Here we provide the final report on the integrated analysis of the safety profile of cladribine tablets 3.5 mg/kg from the clinical development program, including final data from the PREMIERE registry. Methods: Safety data for cladribine tablets 3.5 mg/kg from three previously reported Phase III studies (CLARITY, CLARITY Extension and ORACLE-MS), as well as the prospective, observational PREMIERE registry (which ran from November 2009 to October 2018; consisting of patients who had participated in at least one of the Phase III trials) were combined to provide the Monotherapy Oral cohort. Serious adverse events (SAEs) and predefined SAEs of special interest were recorded. Observation-adjusted incidence rates per 100 patient-years (Adj-AE per 100 PY) were used to assess adverse events (AEs). Standardized incidence ratios for malignancies were calculated in relation to a matched GLOBOCAN reference population, and risk differences (cladribine tablets versus placebo) were estimated. Results: The Monotherapy Oral cohort comprised 923 patients who received cladribine tablets 3.5 mg/kg and 641 patients who received placebo. Overall, the reported number of SAEs was higher in the cladribine tablets 3.5 mg/kg group (133/923 [14.4%] patients with at least 1 SAE), versus the placebo group (68/641 [10.6%] patients with at least 1 SAE). Four patients in the cladribine tablets 3.5 mg/kg group had lymphopenia classified as a serious event (resulting in an Adj-AE of 0.10 per 100 PY) and 2 patients had serious herpes zoster (resulting in an Adj-AE of 0.05 per 100 PY). There were no cases in the corresponding placebo groups. There was no difference between the cladribine tablets 3.5 mg/kg group and placebo in the overall incidence of infections. However herpetic infection AEs occurred more frequently in the cladribine tablets 3.5 mg/kg group (driven primarily by herpes zoster, followed by oral herpes and herpes simplex). Overall, there was a numerical imbalance in malignancy incidence between cladribine tablets 3.5 mg/kg and placebo, with an Adj-AE of 0.26 and 0.12 per 100 PY, respectively; however the difference was not statistically significant. The rate of malignancies observed with cladribine tablets 3.5 mg/kg in the final integrated safety analysis was not different from the expected rate in the matched GLOBOCAN reference population (standardized incidence ratio, 0.88; 95% CI, 0.44-1.69). Conclusion: Additional patient-years of observation do not significantly alter the conclusions of earlier interim analyses, and no new major safety findings were identified in this consolidated analysis of safety data of cladribine tablets 3.5 mg/kg monotherapy in patients with relapsing-remitting multiple sclerosis
Effect of tetragonal distortion on ferroelectric domain switching: A case study on La-doped BiFeO3-PbTiO3 ceramics
The ferroelectric and piezoelectric properties of (1-x)BiFeO3-xPbTiO(3) (BF-PT) ceramics were investigated as a function of tetragonal distortion. The latter was adjusted by employing La-doping (0-30 at %) while keeping the material near the morphotropic phase boundary by varying x between 0.35 and 0.46. This allows changing the c/a ratio of tetragonal BF-PT in the range from 1.10-1.01 and consequently alters the level of compatibility stresses. It was found that the c/a ratio has a significant influence on domain switching as inferred from electric field induced polarization, strain hysteresis, and Rayleigh measurements. Specifically, a threshold c/a ratio of about 1.045 was identified below which the electric field induced domain mobility increases sharply.open342
Modeling pathogenesis of emergent and pre-emergent human coronaviruses in mice
The emergence of highly pathogenic human coronaviruses (hCoVs) in the last two decades has illuminated their potential to cause high morbidity and mortality in human populations and disrupt global economies. Global pandemic concerns stem from their high mortality rates, capacity for human-to-human spread by respiratory transmission, and complete lack of approved therapeutic countermeasures. Limiting disease may require the development of virus-directed and host-directed therapeutic strategies due to the acute etiology of hCoV infections. Therefore, understanding how hCoV-host interactions cause pathogenic outcomes relies upon mammalian models that closely recapitulate the pathogenesis of hCoVs in humans. Pragmatism has largely been the driving force underpinning mice as highly effective mammalian models for elucidating hCoV-host interactions that govern pathogenesis. Notably, tractable mouse genetics combined with hCoV reverse genetic systems has afforded the concomitant manipulation of virus and host genetics to evaluate virus-host interaction networks in disease. In addition to assessing etiologies of known hCoVs, mouse models have clinically predictive value as tools to appraise potential disease phenotypes associated with pre-emergent CoVs. Knowledge of CoV pathogenic potential before it crosses the species barrier into the human population provides a highly desirable preclinical platform for addressing global pathogen preparedness, an overarching directive of the World Health Organization. Although we recognize that results obtained in robust mouse models require evaluation in non-human primates, we focus this review on the current state of hCoV mouse models, their use as tractable complex genetic organisms for untangling complex hCoV-host interactions, and as pathogenesis models for preclinical evaluation of novel therapeutic interventions
Atomically thin boron nitride: a tunnelling barrier for graphene devices
We investigate the electronic properties of heterostructures based on
ultrathin hexagonal boron nitride (h-BN) crystalline layers sandwiched between
two layers of graphene as well as other conducting materials (graphite, gold).
The tunnel conductance depends exponentially on the number of h-BN atomic
layers, down to a monolayer thickness. Exponential behaviour of I-V
characteristics for graphene/BN/graphene and graphite/BN/graphite devices is
determined mainly by the changes in the density of states with bias voltage in
the electrodes. Conductive atomic force microscopy scans across h-BN terraces
of different thickness reveal a high level of uniformity in the tunnel current.
Our results demonstrate that atomically thin h-BN acts as a defect-free
dielectric with a high breakdown field; it offers great potential for
applications in tunnel devices and in field-effect transistors with a high
carrier density in the conducting channel.Comment: 7 pages, 5 figure
Increasing the translation of mouse models of MERS coronavirus pathogenesis through kinetic hematological analysis
Newly emerging viral pathogens pose a constant and unpredictable threat to human and animal health. Coronaviruses (CoVs) have a penchant for sudden emergence, as evidenced by severe acute respiratory syndrome coronavirus (SARS-CoV), Middle East respiratory syndrome CoV (MERS-CoV) and most recently, swine acute diarrhea syndrome coronavirus (SADS-CoV). Small animal models of emerging viral pathogenesis are crucial to better understand the virus and host factors driving disease progression. However, rodent models are often criticized for their limited translatability to humans. The complete blood count is the most ordered clinical test in the United States serving as the cornerstone of clinical medicine and differential diagnosis. We recently generated a mouse model for MERS-CoV pathogenesis through the humanization of the orthologous entry receptor dipeptidyl peptidase 4 (DPP4). To increase the translatability of this model, we validated and established the use of an automated veterinary hematology analyzer (VetScan HM5) at biosafety level 3 for analysis of peripheral blood. MERS-CoV lung titer peaked 2 days post infection concurrent with lymphopenia and neutrophilia in peripheral blood, two phenomena also observed in MERS-CoV infection of humans. The fluctuations in leukocyte populations measured by Vetscan HM5 were corroborated by standard flow cytometry, thus confirming the utility of this approach. Comparing a sublethal and lethal dose of MERS-CoV in mice, analysis of daily blood draws demonstrates a dose dependent modulation of leukocytes. Major leukocyte populations were modulated before weight loss was observed. Importantly, neutrophil counts on 1dpi were predictive of disease severity with a lethal dose of MERS-CoV highlighting the predictive value of hematology in this model. Taken together, the inclusion of hematological measures in mouse models of emerging viral pathogenesis increases their translatability and should elevate the preclinical evaluation of MERS-CoV therapeutics and vaccines to better mirror the complexity of the human condition
Oscillatory Shear Flow-Induced Alignment of Lamellar Melts of Hydrogen-Bonded Comb Copolymer Supramolecules
In this work we present the orientational behavior of comb copolymer-like supramolecules P4VP(PDP)1.0, obtained by hydrogen bonding between poly(4-vinylpyridine) and pentadecylphenol, during large-amplitude oscillatory shear flow experiments over a broad range of frequencies (0.001-10 Hz). The alignment diagram, presenting the macroscopic alignment in T/TODT vs ω/ωc, contains three regions of parallel alignment separated by a region of perpendicular alignment. For our material, the order-disorder temperature TODT = 67 °C and ωc, the frequency above which the distortion of the chain conformation dominates the materials’ viscoelasticity, is around 0.1 Hz at 61 °C. For the first time flipping from a pure transverse alignment via biaxial transverse/perpendicular alignment to a perpendicular alignment as a function of the strain amplitude was found.
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