Statistical models and the theory of hypothesis testing in medicine

Purpose: The purpose of this work is to develop statistical approaches for treatment efficiency analysis on a medical case. These methods include the effect evaluation method performed with various preparations in regards to several factors such as the patient‘s blood state and his/her biochemical values. Design/Methodology/Approach: The results of this survey were divided into three groups: the first included the blood biochemistry values before the test, the second — an hour after the test, the the third — two hours after the test. When visually comparing the results of the analyses of the three groups, it was possible to assume that the load of FLC did not significantly affect the biochemistry of the patients' blood. To test this medical assumption, various statistical criteria of the theory of testing statistical hypotheses have been applied. Findings: Statistical analysis of changes in the level of lipase and triglycerides in the biochemical analysis of the blood of patients with chronic pancreatitis after ingestion of food containing medium-chain fatty acids showed that there is no overall disruption in the functioning of the pancreas. Practical implications: Clinical practice has shown that more than 85% of patients tolerated testing with medium chain fatty acids, not experiencing a painful abdominal symptom and other negative consequences of a violation of external secretion of the pancreas. Originality/Value: In clinical practice, the Russian Academy of Medical Sciences for the first time took into account the results of a statistical analysis.peer-reviewe

Tobacco peroxidase as a new reagent for amperometric biosensors

The results of testing a new enzyme, anionic tobacco peroxidase (TOP), in various amperometric biosensors are summarized. The biochemical and electrochemical properties of the enzyme are briefly characterized. As compared to the commonly used cationic peroxidase from horseradish roots, TOP exhibits a wider optimum stability pH range, higher stability to inactivation with hydrogen peroxide, and higher efficiency in direct electron-transfer processes. The enzyme immobilized by adsorption on graphite is effective in determining aminophenols and aromatic diamines under flow conditions with a detection limit of 10 nM. Upon immobilization on graphite by incorporation into a get of a redox-active polymer (crosslinked polyvinylimidazole with osmium 4,4'-dimethylbipyridinium chloride), TOP exhibited sensitivity and stability comparable to those of horseradish peroxidase and a wider linearity range. Upon immobilization on a self-assembled thiol monolayer at a gold electrode, TOP was much superior to horseradish peroxidase in the sensitivity of determining hydrogen peroxide, regardless of the charge of the monolayer. Prospects for the further use of the native enzyme and its genetically engineered unglycosylated form are considered

Identifying key research objectives to make European forests greener for bats

Bats are a biodiverse mammal order providing key ecosystem services such as pest suppression, pollination and seed dispersal. Bats are also very sensitive to human actions, and significant declines in many bat populations have been recorded consequently. Many bat species find crucial roosting and foraging opportunities in European forests. Such forests have historically been exploited by humans and are still influenced by harvesting. One of the consequences of this pressure is the loss of key habitat resources, often making forests inhospitable to bats. Despite the legal protection granted to bats across Europe, the impacts of forestry on bats are still often neglected. Because forest exploitation influences forest structure at several spatial scales, economically viable forestry could become more sustainable and even favour bats. We highlight that a positive future for bat conservation that simultaneously benefits forestry is foreseeable, although more applied research is needed to develop sound management. Key future research topics include the detection of factors influencing the carrying capacity of forests, and determining the impacts of forest management and the economic importance of bats in forests. Predictive tools to inform forest managers are much needed, together with greater synergies between forest managers and bat conservationists

Novel Lyssaviruses Isolated from Bats in Russia

Two new rabies-related viruses were discovered in Russia during 2002. Viruses were isolated from bats in Eastern Siberia near Baikal Lake and in the western Caucasus Mountains. After preliminary antigenic and genetic characterization, we found that both viruses should be considered as new putative lyssavirus genotypes

Non-canonical Keap1-independent activation of Nrf2 in astrocytes by mild oxidative stress

The transcription factor Nrf2 is a stress-responsive master regulator of antioxidant, detoxification and proteostasis genes. In astrocytes, Nrf2-dependent gene expression drives cell-autonomous cytoprotection and also non-cell-autonomous protection of nearby neurons, and can ameliorate pathology in several acute and chronic neurological disorders associated with oxidative stress. However, the value of astrocytic Nrf2 as a therapeutic target depends in part on whether Nrf2 activation by disease-associated oxidative stress occludes the effect of any Nrf2-activating drug. Nrf2 activation classically involves the inhibition of interactions between Nrf2's Neh2 domain and Keap1, which directs Nrf2 degradation. Keap1 inhibition is mediated by the modification of cysteine residues on Keap1, and can be triggered by electrophilic small molecules such as tBHQ. Here we show that astrocytic Nrf2 activation by oxidative stress involves Keap1-independent non-canonical signaling. Keap1 deficiency elevates basal Nrf2 target gene expression in astrocytes and occludes the effects of tBHQ, oxidative stress still induced strong Nrf2-dependent gene expression in Keap1-deficient astrocytes. Moreover, while tBHQ prevented protein degradation mediated via Nrf2's Neh2 domain, oxidative stress did not, consistent with a Keap1-independent mechanism. Moreover the effects of oxidative stress and tBHQ on Nrf2 target gene expression are additive, not occlusive. Mechanistically, oxidative stress enhances the transactivation potential of Nrf2's Neh5 domain in a manner dependent on its Cys-191 residue. Thus, astrocytic Nrf2 activation by oxidative stress involves Keap1-independent non-canonical signaling, meaning that further Nrf2 activation by Keap1-inhibiting drugs may be a viable therapeutic strategy

Random-Matrix Theory of Quantum Transport

This is a comprehensive review of the random-matrix approach to the theory of phase-coherent conduction in mesocopic systems. The theory is applied to a variety of physical phenomena in quantum dots and disordered wires, including universal conductance fluctuations, weak localization, Coulomb blockade, sub-Poissonian shot noise, reflectionless tunneling into a superconductor, and giant conductance oscillations in a Josephson junction.Comment: 85 pages including 52 figures, to be published in Rev.Mod.Phy

Recombinant horseradish peroxidase- and cytochrome c-based two-electrode system for detection of superoxide radicals

The reliable detection of a superoxide anion radical O-2(.-) - is complicated by its spontaneous dismutation reaction to H2O2 at acidic pHs. To simultaneously detect both O-2(.-) and H2O2 produced in the course of its spontaneous dismutation, an electrochemical two-electrode system based on cytochrome c (cyt c) and recombinant horseradish peroxidase (rHRP) was applied. Therewith, a limited applicability of the cyt c system for the reliable monitoring of O-2(.-) in acidic and neutral solutions was shown. It was demonstrated that both the reaction of O-2(.-) dismutation to H2O2 and the reaction between the formed H2O2 and O-2(.-) chemically decrease the amount of the initially present O-2(.-) decreasing the sensitivity and reliability of the electrochemical detection at acidic pH. However, by appropriately varying solution pH, the concentration of O-2(.-) - initially injected in the system can be estimated from the analysis of calibration curves for H2O2 obtained with highly sensitive rHRP-modified electrode system at pH 6.0 and 7.0. (C) 2004 Elsevier B.V. All rights reserved