Антиоксидантна активність піридилгідразонів ароматичних альдегідів

The kinetic parameters of the antioxidant activity of pyridylhydrazones derivatives of aromatic aldehydes in the initiated oxidation of ethylbenzene have been determined by the chemiluminescent method. The antioxidants studied have higher values of the reaction rate constants with peroxy radicals k7 compared to ionol. In the conditions of autooxidation of ethylbenzene the efficiency of the antioxidants studied reduces. It has been found that 3-pyridylhydrazon-3,5-dimethyl-4-hydroxybenzaldehyde interacts with cumene hydroperoxide. The regularities of the inhibitory effect of pyridylhydrazones in heterogeneous systems have been studied. Interaction of pyridylhydrazones with НО• radicals has been investigated by the chemiluminescent method in water solution. It has been determined that pyridylhydrazones show a high activity towards НО• radicals. In the initiated azodiisobutyronitrile oxidation the emulsion of ethylbenzene : water derivative of pyridylhydrazones has revealed a high antioxidant activity. In the presence of hydrophobic derivatives in molecules of antioxidants the values of log P and the induction period (τ/τ0) increase. When inhibiting the initiated oxidation of phosphatidylcholine dispersion pyridylhydrazones show practically twice higher antioxidant activity in comparison with ionol.Определены кинетические параметры антиоксидантной активности производных пиридилгидразонов ароматических альдегидов при инициированном окислении этилбензола хемилюминесцентным методом. Исследованные антиоксиданты имеют более высокие значения констант скорости реакции с пероксирадикалами k7 по сравнению с ионолом. В условиях высокотемпературного автоокисления этилбензола эффективность пиридилгидразонов снижается. Установлено, что 3-пиридилгидразон-3,5- диметил-4-гидроксибензальдегида взаимодействует с гидропероксидом кумила. Хемилюминесцентным методом показано, что пиридилгидразоны проявляют высокую активность по отношению к НО• радикалам в водном растворе. Изучены закономерности ингибирующего действия пиридилгидразонов в гетерогенных системах. Установлена зависимость антиокислительной активности гидразонов от значений показателей липофильности антиоксидантов. При ингибировании инициированного окисления дисперсии фосфатидилхолина пиридилгидразоны проявляют практически вдвое большую антиоксидантную активность по сравнению с ионолом. Визначені кінетичні параметри антиоксидантної активності похідних піридилгідразонів ароматичних альдегідів при ініційованому окисненні етилбензолу хемілюмінесцентним методом. Досліджені антиоксиданти мають більші значення констант швидкості реакції з пероксильними радикалами k7 у порівнянні з іонолом. В умовах високотемпературного автоокиснення етилбензолу ефективність досліджених антиоксидантів знижується. Встановлено, що 3-піридилгідразон-3,5-диметил-4-гідроксибензальдегіду взаємодіє з гідропероксидом кумілу. Хемілюмінесцентним методом показано, що піридилгідразони виявляють високу активність щодо НО• радикалів у водному розчині. Вивчені закономірності інгібуючої дії піридилгідразонів у гетерогенних системах. Встановлено залежність антиокиснювальної активності гідразонів від значень показників ліофільності антиоксидантів. При інгібуванні ініційованого окиснення дисперсії фосфатидилхоліну піридилгідразони проявляють практично вдвічі більшу АОА, ніж іонол

Curvature homogeneous spacelike Jordan Osserman pseudo-Riemannian manifolds

Let s be at least 2. We construct Ricci flat pseudo-Riemannian manifolds of signature (2s,s) which are not locally homogeneous but whose curvature tensors never the less exhibit a number of important symmetry properties. They are curvature homogeneous; their curvature tensor is modeled on that of a local symmetric space. They are spacelike Jordan Osserman with a Jacobi operator which is nilpotent of order 3; they are not timelike Jordan Osserman. They are k-spacelike higher order Jordan Osserman for $2\le k\le s$; they are k-timelike higher order Jordan Osserman for $s+2\le k\le 2s$, and they are not k timelike higher order Jordan Osserman for $2\le s\le s+1$.Comment: Update bibliography, fix minor misprint

Mycobacterium bovis Strains Causing Smear-Positive Human Tuberculosis, Southwest Ireland

Mycobacterium bovis caused 3% of human tuberculosis cases in southwest Ireland during 1998–2006. Of 11 M. bovis strains genotyped, 9 belonged to common animal spoligotypes. Seven strains were from sputum and potential sources of human-centered disease transmission. Ten-locus variable-number tandem repeat typing gave unique strain profiles and would detect disease outbreaks

An Integrated Approach to Rapid Diagnosis of Tuberculosis and Multidrug Resistance Using Liquid Culture and Molecular Methods in Russia

Objective: To analyse the feasibility, cost and performance of rapid tuberculosis (TB) molecular and culture systems, in a high multidrug-resistant TB (MDR TB) middle-income region (Samara, Russia) and provide evidence for WHO policy change. Methods: Performance and cost evaluation was conducted to compare the BACTEC™ MGIT™ 960 system for culture and drug susceptibility testing (DST) and molecular systems for TB diagnosis, resistance to isoniazid and rifampin, and MDR TB identification compared to conventional Lowenstein-Jensen culture assays. Findings: 698 consecutive patients (2487 sputum samples) with risk factors for drug-resistant tuberculosis were recruited. Overall M. tuberculosis complex culture positivity rates were 31.6% (787/2487) in MGIT and 27.1% (675/2487) in LJ (90.5% and 83.2% for smear-positive specimens). In total, 809 cultures of M. tuberculosis complex were isolated by any method. Median time to detection was 14 days for MGIT and 36 days for LJ (10 and 33 days for smear positive specimens) and indirect DST in MGIT took 9 days compared to 21 days on LJ. There was good concordance between DST on LJ and MGIT (96.8% for rifampin and 95.6% for isoniazid). Both molecular hybridization assay results correlated well with MGIT DST results, although molecular assays generally yielded higher rates of resistance (by approximately 3% for both isoniazid and rifampin). Conclusion: With effective planning and logistics, the MGIT 960 and molecular based methodologies can be successfully introduced into a reference laboratory setting in a middle incidence country. High rates of MDR TB in the Russian Federation make the introduction of such assays particularly useful. © 2009 Balabanova et al

Performance of the Genotype® MTBDRPlus assay in the diagnosis of tuberculosis and drug resistance in Samara, Russian Federation

<p>Abstract</p> <p>Background</p> <p>Russia is a high tuberculosis (TB) burden country with a high prevalence of multidrug resistant tuberculosis (MDRTB). Molecular assays for detection of MDRTB on clinical specimens are not widely available in Russia.</p> <p>Results</p> <p>We performed an evaluation of the GenoType^®MTBDRplus assay (HAIN Lifescience GmbH, Germany) on a total of 168 sputum specimens from individual patients at a public health laboratory in Central Russia, as a model of a middle income site in a region with high levels of drug resistance. Phenotypic drug resistance tests (DST) were performed on cultures derived from the same sputum specimens using the BACTEC 960 liquid media system.</p> <p>Interpretable GenoType^®MTBDRplus results were obtained for 154(91.7%) specimens with readability rates significantly higher in sputum specimens graded 2+ and 3+ compared to 1+ (RR = 1.17 95%CI 1.04–1.32). The sensitivity and specificity of the assay for the detection of rifampicin (RIF) and isoniazid (INH) resistance and MDR was 96.2%, 97.4%, 97.1% and 90.7%, 83.3%, 88.9% respectively. Mutations in codon 531 of the <it>rpoB </it>gene and codon 315 of the <it>katG </it>gene dominated in RIF and INH resistant strains respectively. Disagreements between phenotypical and molecular tests results (12 samples) could be explained by the presence of rare mutations in strains circulating in Russia and simultaneous presence of resistant and sensitive bacilli in sputum specimens (heteroresistance).</p> <p>Conclusion</p> <p>High sensitivity, short turnaround times and the potential for screening large numbers of specimens rapidly, make the GenoType^®MTBDRplus assay suitable as a first-line screening assay for drug resistant TB.</p

Increasing trends in HIV and TB rates in Odessa and the Ukraine

Notification rates for HIV and tuberculosis (TB) have increased in the Ukraine and particularly in Odessa. In 1962, the incidence of TB in Odessa region was 178 cases per 100,000 cases, declining to 73.0, 42.0 and 41.6 cases per 100,000 in 1972, 1982 and 1992, respectively. In 2002, TB incidence and prevalence were 80.4 and 330.1/100,000 population, respectively. TB mortality in the port almost doubled from 10.2/100,000 to 21.6/100,000 between 1990 and 2001. In 2002, the HIV incidence and prevalence and AIDS incidence and prevalence were 46.4 and 241.0 cases/100,000 population and 14.5/100,000 and 26.9/100,000, respectively. There are increasing numbers of TB cases co-infected with HIV (200 in 2002), suggesting that the HIV and TB epidemics are converging. Significant effort is needed for the effective control of these two outbreaks to prevent high levels of morbidity and mortality from these diseases

Locally conformally Berwald manifolds and compact quotients of reducible manifolds by homotheties

We study locally conformally Berwald metrics on closed manifolds which are not globally conformally Berwald. We prove that the characterization of such metrics is equivalent to characterizing incomplete, simply-connected, Riemannian manifolds with reducible holonomy group whose quotient by a group of homotheties is closed. We further prove a de Rham type splitting theorem which states that if such a manifold is analytic, it is isometric to the Riemannian product of a Euclidean space and an incomplete manifold

Detection of Mutations Associated with Isoniazid and Rifampin Resistance in Mycobacterium tuberculosis Isolates from Samara Region, Russian Federation

High incidence rates of isoniazid-, rifampin-, and multiple-drug-resistant tuberculosis have been reported in countries of the former Soviet Union (FSU). Genotypic (unlike phenotypic) drug resistance assays do not require viable cultures but require accurate knowledge of both the target gene and the mutations associated with resistance. For these assays to be clinically useful, they must be able to detect the range of mutations seen in isolates from the population of tuberculosis patients to which they are applied. Two novel macroarrays were applied to detect mutations associated with rifampin (rpoB) and isoniazid (katG and inhA) resistance. In a sample of 233 isolates from patients in Samara, central Russia, 46.5% of isolates possessed mutations in both the rpoB and the katG (or inhA) genes. Combined results from the macroarrays demonstrated concordance in 95.4 and 90.4% of phenotypically defined rifampin- and isoniazid-resistant isolates, respectively. The contribution of different mutations to resistance was comparable to that reported previously for non-FSU countries, with 90% of rifampin-resistant isolates and 93% of isoniazid resistant isolates due to rpoB531 and katG315 mutations, respectively. The percentage of phenotypically resistant rifampin isolates with no mutations in the rpoB codons 509 to 536 was 4.2%, which was similar to previous reports. Novel macroarrays offer a rapid, accurate, and relatively cheap system for the identification of rifampin-, isoniazid-, and multiple-drug-resistant Mycobacterium tuberculosis isolates

M. tuberculosis microvariation is common and is associated with transmission: analysis of three years prospective universal sequencing in England

Background: The prevalence, association with disease status, and public health impact of infection with mixtures of M. tuberculosis strains is unclear, in part due to limitations of existing methods for detecting mixed infections. Methods: We developed an algorithm to identify mixtures of M. tuberculosis strains using next generation sequencing data, assessing performance using simulated sequences. We identified mixed M. tuberculosis strains when there was at least one mixed nucleotide position, and where both the mixture’s components were present in similar isolates from other individuals. We determined risk factors for mixed infection among isolations of M. tuberculosis in England using logistic regression. We used survival analyses to assess the association between mixed infection and putative transmission. Findings: 6,560 isolations of TB were successfully sequenced in England 2016-2018. Of 3,691 (56%) specimens for which similar sequences had been isolated from at least two other individuals, 341 (9.2%) were mixed. Infection with lineages other than Lineage 4 were associated with mixed infection. Among the 1,823 individuals with pulmonary infection with Lineage 4 M. tuberculosis, mixed infection was associated with significantly increased risk of subsequent isolation of closely related organisms from a different individual (HR 1.43, 95% CI 1.05,1.94), indicative of transmission. Interpretation: Mixtures of transmissible strains occur in at least 5% of tuberculosis infections in England; when present in pulmonary disease, such mixtures are associated with an increased risk of tuberculosis transmission.</p