Modeling of Biochemical Nitrate Reduction in Constant Electric Field

Experiments on the bioelectrochemical stimulation of enzyme reduction of nitrate to nitrite in a potentiostatic regime at different catode potentials were carried out. It was established that the stimulation effect of the constant electric field on nitrate reduction is also relevant for cell-free enzyme preparation, i.e. the effect is related to the constitutive enzymes nitrate-reductase and nitrite-reductase, contained in the cell membranes. Mathematical modeling of these experimental data as well as data for the same process accomplished by living immobilized cells was carried out. The purpose of the modeling was to select the most suitable kinetic model and then estimate the kinetic parameters and their dependence on the cathode potential. The mathematical models were based on the Michaelis-Menten kinetics taking into account inhibition by nitrate and nitrite. This modeling helped to conclude that the stimulation consists of two effects: enhanced maximum rate of nitrate enzyme reduction and faster nitrite reduction to eliminate nitrite inhibition on the overall process. It was found that the maximum reaction rates of nitrate and nitrite reduction depend on the cathode potential with maxima at + 0.01 V vs. the saturated hydrogen electrode

Modeling of Biochemical Nitrate Reduction in Constant Electric Field

Experiments on the bioelectrochemical stimulation of enzyme reduction of nitrate to nitrite in a potentiostatic regime at different catode potentials were carried out. It was established that the stimulation effect of the constant electric field on nitrate reduction is also relevant for cell-free enzyme preparation, i.e. the effect is related to the constitutive enzymes nitrate-reductase and nitrite-reductase, contained in the cell membranes. Mathematical modeling of these experimental data as well as data for the same process accomplished by living immobilized cells was carried out. The purpose of the modeling was to select the most suitable kinetic model and then estimate the kinetic parameters and their dependence on the cathode potential. The mathematical models were based on the Michaelis-Menten kinetics taking into account inhibition by nitrate and nitrite. This modeling helped to conclude that the stimulation consists of two effects: enhanced maximum rate of nitrate enzyme reduction and faster nitrite reduction to eliminate nitrite inhibition on the overall process. It was found that the maximum reaction rates of nitrate and nitrite reduction depend on the cathode potential with maxima at + 0.01 V vs. the saturated hydrogen electrode

Suitability of òhe modality virtual bronchoscopy with aspiration of a foreign body

Aspirations of foreign bodies are life-threatening among children and elderly patients requiring urgent medical assistance. The aim of the study is to present summarized results from various authors' studies to reveal VB's diagnostic abilities for suspected aspiration of a foreign body. VB has been shown to be a particularly useful non-invasive modality for the complex tracheobronchial tree assessment for suspected aspiration of a foreign body due to its high sensitivity, specificity and validity. MDCT VB with MPR allows accurate localization of the foreign body, but in secondary inflammatory changes and secretions it does not provide accurate information about the form and type of the finding. VB cannot replace FB ("gold standard") but successfully supports and complements it. MDCT could provide early diagnosis in cases of suspected aspiration of a foreign body in children and adults and avoid real bronchoscopy in patients with poor overall condition

Expression Analysis of the Theileria parva Subtelomere-Encoded Variable Secreted Protein Gene Family

Background The intracellular protozoan parasite Theileria parva transforms bovine lymphocytes inducing uncontrolled proliferation. Proteins released from the parasite are assumed to contribute to phenotypic changes of the host cell and parasite persistence. With 85 members, genes encoding subtelomeric variable secreted proteins (SVSPs) form the largest gene family in T. parva. The majority of SVSPs contain predicted signal peptides, suggesting secretion into the host cell cytoplasm. Methodology/Principal Findings We analysed SVSP expression in T. parva-transformed cell lines established in vitro by infection of T or B lymphocytes with cloned T. parva parasites. Microarray and quantitative real-time PCR analysis revealed mRNA expression for a wide range of SVSP genes. The pattern of mRNA expression was largely defined by the parasite genotype and not by host background or cell type, and found to be relatively stable in vitro over a period of two months. Interestingly, immunofluorescence analysis carried out on cell lines established from a cloned parasite showed that expression of a single SVSP encoded by TP03_0882 is limited to only a small percentage of parasites. Epitope-tagged TP03_0882 expressed in mammalian cells was found to translocate into the nucleus, a process that could be attributed to two different nuclear localisation signals. Conclusions Our analysis reveals a complex pattern of Theileria SVSP mRNA expression, which depends on the parasite genotype. Whereas in cell lines established from a cloned parasite transcripts can be found corresponding to a wide range of SVSP genes, only a minority of parasites appear to express a particular SVSP protein. The fact that a number of SVSPs contain functional nuclear localisation signals suggests that proteins released from the parasite could contribute to phenotypic changes of the host cell. This initial characterisation will facilitate future studies on the regulation of SVSP gene expression and the potential biological role of these enigmatic proteins

Evacetrapib and Cardiovascular Outcomes in High-Risk Vascular Disease

BACKGROUND: The cholesteryl ester transfer protein inhibitor evacetrapib substantially raises the high-density lipoprotein (HDL) cholesterol level, reduces the low-density lipoprotein (LDL) cholesterol level, and enhances cellular cholesterol efflux capacity. We sought to determine the effect of evacetrapib on major adverse cardiovascular outcomes in patients with high-risk vascular disease. METHODS: In a multicenter, randomized, double-blind, placebo-controlled phase 3 trial, we enrolled 12,092 patients who had at least one of the following conditions: an acute coronary syndrome within the previous 30 to 365 days, cerebrovascular atherosclerotic disease, peripheral vascular arterial disease, or diabetes mellitus with coronary artery disease. Patients were randomly assigned to receive either evacetrapib at a dose of 130 mg or matching placebo, administered daily, in addition to standard medical therapy. The primary efficacy end point was the first occurrence of any component of the composite of death from cardiovascular causes, myocardial infarction, stroke, coronary revascularization, or hospitalization for unstable angina. RESULTS: At 3 months, a 31.1% decrease in the mean LDL cholesterol level was observed with evacetrapib versus a 6.0% increase with placebo, and a 133.2% increase in the mean HDL cholesterol level was seen with evacetrapib versus a 1.6% increase with placebo. After 1363 of the planned 1670 primary end-point events had occurred, the data and safety monitoring board recommended that the trial be terminated early because of a lack of efficacy. After a median of 26 months of evacetrapib or placebo, a primary end-point event occurred in 12.9% of the patients in the evacetrapib group and in 12.8% of those in the placebo group (hazard ratio, 1.01; 95% confidence interval, 0.91 to 1.11; P=0.91). CONCLUSIONS: Although the cholesteryl ester transfer protein inhibitor evacetrapib had favorable effects on established lipid biomarkers, treatment with evacetrapib did not result in a lower rate of cardiovascular events than placebo among patients with high-risk vascular disease. (Funded by Eli Lilly; ACCELERATE ClinicalTrials.gov number, NCT01687998 .)

Microwave dielectric properties of Mg1+x(CayTix+y)Al2-2x-2yO4 system

International audienc