The influence of antioxidants and cycloheximide on the level of nitric oxide in the livers of mice in vivo

AbstractWhen injected into mice prior to the NO generation increase induced with lipopolysaccharide (LPS) from Escherichia coli, exogenous antioxidants diethyldithiocarbamate (DETC) or phenazan (sodium 3.5-di-tert-butyl-4-oxiphenylpropionate) as well as the inhibitor of protein biosynthesis, cycloheximide (CHI) attenuated the NO production in mouse liver in vivo. These data demonstrated the key role of free radicals, which were likely, active oxygen species, in the synthesis of inducible NO-synthase (iNOS) responsible for the NO production in this organ. Similar effects of phenazan and CHI were observed in livers of mice treated with γ-irradiation or LPS + Fe2+-citrate, which suggested that these treatments also induced 1NOS synthesis through initiating the action of active oxygen species. The rate of NO synthesis was estimated by accumulation of paramagnetic mononitrosyl iron complexes with DETC (MNIC-DETC) detected using the EPR method. The formation of MNIC-DETC complexes was found in the brain of mice pre-treated with LPS + Fe2+-citrate which seemed to be due to iNOS synthesis stimulated by this treatment

Создание методик определения содержания основных компонентов в реактивах, используемых для синтеза стандартных образцов состава

Actuality of the research. The need for the development and validation of analysis methods of reagents used for the introduction of elements into reference materials, certified according to the procedure of preparation. The purpose. Development and certification of methods for determining the content of the main component in the reagents used to prepare reference materials. Research methods. Gravimetry, titration, atomic emission spectral analysis with arc excitation, atomic emission spectral analysis with inductively coupled plasma as an excitation source, mass spectral analysis with inductively coupled plasma as ion source. Results. The characteristics of the error of the measurement results are estimated, the Certificates of Attestation of the methods are received, the information is included in the Federal Information Fund.Актуальность исследования. В  статье  обоснована необходимость разработки и аттестации методик анализа реактивов, применяемых для введения элементов в  стандартные образцы состава, аттестуемые по процедуре приготовления. Цель работы. Разработка и аттестация методик определения содержания основного компонента в реактивах, используемых для приготовления стандартных образцов состава.Методы исследования. Гравиметрия, титриметрия, атомный эмиссионный спектральный анализ с дуговым возбуждением, атомный эмиссионный спектральный анализ с индуктивно связанной плазмой в качестве источника возбуждения, масс-спектральный анализ с индуктивно связанной плазмой в качестве источника ионов.Результаты. Оценены характеристики погрешности результатов измерений, получены Свидетельства об аттестации методик, сведения внесены в Федеральный информационный фонд.

DEVELOPMENT OF METHODS FOR THE ANALYSIS OF SYNTHETIC MACRO- AND NANOSCALE POWDERS OF ALUMINUM-MAGNESIUM AND ALUMINUM-MANGANESE SPINEL

An atomic emission spectral technique for determining the main and doping elements in spinel targets and in nanopowders obtained from them by laser ablation has been developed. The technique is implemented on spectrometer with inductively coupled plasma Optima 2100 DV.Выражаем благодарность сотрудникам Лаборатории квантовой электроники Ин-ститута электрофизики УрО РАН за постановку задач и предоставленные для иссле-дования материалы

Direct Detection of Reactive Nitrogen Species in Experimental Autoimmune Uveitis

PURPOSE: Demonstrate unequivocally the generation of nitric oxide in experimental autoimmune uveoretinitis by electron spin resonance spectroscopy (ESR) using ferrous iron complex of N-methyl-D-glucamine dithiocarbamate, (MGD)(2)-Fe(2+), as a spin trap. METHODS: Experimental autoimmune uveitis was induced in Lewis rats, and at the peak of the intraocular inflammation, the animals received intravitreous injections of the spin trap. The retina and choroid dissected from the enucleated globes were subjected to ESR. Similarly, the retina and choroid obtained at the peak of experimental autoimmune uveo-retinitis (EAU) were placed in a vial containing luminal, and chemiluminescence was counted on a Packard liquid scintillation analyzer. RESULTS: The ESR three-line spectrum (g=2.04; a(N)=12.5 G) obtained was characteristic of the adduct [(MGD)(2)-Fe(2+)-NO]. The majority of this signal was eliminated by the inducible nitric oxide synthase (iNOS) specific inhibitor aminoguanidine injected inflamed retina was detected when compared with that of the non inflamed controls. The chemiluminescent activity was further increased two-fold by the addition of bicarbonate to the inflamed retina; the phenomenon is attributable only to the presence of a high steady-state concentration of peroxynitrite. CONCLUSIONS: The study shows an unequivocal presence of nitric oxide in EAU retina and choroid and the generation of peroxynitrite. High levels of these reactive nitrogen species generated in the inflamed retina and choroids are certain to cause irreversible tissue damage, especially at the susceptible sites such as photoreceptors

Синтез материалов и оценка метрологических характеристик стандартного образца состава фторцирконата калия

The relevance of the study. For metrological support of control methods for composition ofpotassium fluozirconate, used in the production of metallic zirconium, applied in various technical fields, including nuclear power, electronics, chemical engineering. The purpose: development of synthesis technology, and determination of metrological characteristics of certified reference material for composition ofpotassium fluozirconate (set), intended for metrological support of measuring element mass fraction: hafnium (Hf), silicon (Si), iron (Fe), aluminium (Al), chromium (Cr), tin (Sn), titanium (Ti) in potassium fluozirconate. Research methods: X-ray diffraction, differential scanning colorimetry, thermogravimetric analysis, atomic-emission spectral analysis with arc excitation, mass spectral analysis, X-ray fluorescence analysis. Results. As a result of research a set of certified reference materials for composition of potassium fluozirconate is developed and produced. The CRM type is approved by Federal Agency on Technical Regulating and Metrology and registered in State Register of Approved Reference Material Types under number GSO 10593-2015.Актуальность исследования. Для метрологического обеспечения методов контроля состава фторцирконата калия, используемого при производстве металлического циркония, применяемого в различных областях техники, в том числе атомной энергетике, электронике, химическом машиностроении. Цель работы: разработка технологии синтеза и определение метрологических характеристик стандартного образца состава фторцирконата калия (комплект), предназначенного для метрологического обеспечения измерений массовой доли элементов: гафния (Hf), кремния (Si), железа (Fe), алюминия (Al), хрома (Cr), олова (Sn), титана (Ti) во фторцирконате калия. Методы исследования: рентгенофазовый анализ, дифференциальная сканирующая колориметрия, термогравиметрический анализ, атомно-эмиссионный спектральный анализ с дуговым возбуждением, масс-спект-ральный анализ, рентгенофлуоресцентный анализ. Результаты. По результатам исследований разработан и изготовлен комплект стандартных образцов состава фторцирконата калия, тип которого утвержден Федеральным агентством по техническому регулированию и метрологии и зарегистрирован в Государственном реестре утвержденных типов стандартных образцов под номером ГСО 10593-2015

Direct EPR Detection of Nitric Oxide in Mice Infected with the Pathogenic Mycobacterium Mycobacterium tuberculosis

It has been shown that treatment of mice preinfected with Mycobacterium tuberculosis with spin NO traps (iron complexes with diethyldithiocarbamate) enables detection of large amounts of NO in internal organs 2 and 4 weeks after infection (up to 55–57 μmol/kg of wet lung tissue accumulated with spin NO traps during 30 min). The animals were infected with the drug-sensitive laboratory strain H37Rv and a clinical isolate nonrespondent to antituberculous drugs (the multidrug-resistant strain of M. tuberculosis) obtained from a patient with an active form of tuberculosis. Two weeks after infection with the multidrug-resistant strain, the NO level in the lungs, spleen, liver and kidney increased sharply concurrently with slight lesions of lung tissue. A reverse correlation, i.e., low level of NO in the lungs and other internal organs and extensive injury of lung tissue, was established for H37Rv-infected mice. Four weeks after infection, NO production in the lungs increased dramatically for both M. tuberculosis strains resulting in 80–84% damage of lung tissue. The lesion is suggested to be due to the development of defense mechanisms in M. tuberculosis counteracting NO effects

РАК ТОЛСТОЙ КИШКИ С МИКРОСАТЕЛЛИТНОЙ НЕСТАБИЛЬНОСТЬЮ У ПОЖИЛЫХ БОЛЬНЫХ: РОЛЬ ИММУНОДЕФИЦИТА И КЛИНИЧЕСКИЕ ОСОБЕННОСТИ

Background. Tumors demonstrating the phenomenon of microsatellite instability (MSI) represent a special category of colorectal cancer (CRC). Such neoplasms account for up to 20 % of CRC and are characterized by specific molecular and clinical manifestations, including high immunogenicity and sensitivity to immunotherapy. MSI phenotype occurs in two different groups of patients: young individuals with Lynch syndrome and patients older than 70 years with non-hereditary CRC. We assume that the development of sporadic MSI-positive tumors in elderly patients may be associated with age-dependent decrease in immune defense. The aim of the study was to investigate clinical and morphological characteristics in elderly patients with MSI-positive colorectal cancer. Material and methods. MSI status and mutations in the BRAF gene were tested in a group of 384 CRC patients older than 65 years by PCR-based techniques. A comparative analysis of clinico-pathological features was further conducted in the groups of 23 MSI-positive and 34 MSI-negative CRC cases. Results. MSI-positive phenotype was associated with the proximal tumor location, low degree of differentiation and the presence of the mucinous component in the tumor (p<0.0001, p=0.005, and p=0.0001, respectively). Patients with MSI-positive CRC containing BRAF mutations showed a significant prevalence of RhD-negative erythrocyte phenotype (53.3 % vs 11.8 %, p=0.004). In patients with MSI-positive carcinomas, the increased frequency of preoperative leukocytosis (p=0.009) and lymphopenia (p=0.014) was observed. Conclusion. The increased occurrence of Rh-negative erythrocyte phenotype and white blood formula changes in elderly patients with MSI-positive CRC may indicate the role of immune system disorders in the development of microsatellite-unstable carcinomas.Актуальность. Опухоли с феноменом микросателлитной нестабильности (microsatellite instability, MSI) представляют собой отдельную категорию рака толстой кишки (РТК). Подобные новообразования составляют до 20 % карцином этой локализации и характеризуются своеобразными молекулярными и клиническими проявлениями, в том числе высокой иммуногенностью и чувствительностью к иммунотерапии. Микросателлитная нестабильность встречается у двух разных групп пациентов – молодых больных с синдромом Линча и у пациентов старше 70 лет с ненаследственным РТК. Мы предполагаем, что развитию спорадических MSI-позитивных опухолей у пожилых пациентов может способствовать сопутствующее старению снижение иммунной защиты. Целью исследования стало изучение различных клинико-морфологических характеристик у пожилых больных с MSI-позитивным РТК. Материал и методы. Микросателлитная нестабильность и мутация V600E в гене BRAF оценивались методами, основанными на ПЦР, в группе из 384 больных РТК старше 65 лет. Сравнительный анализ клинических и патоморфологических особенностей выполнен у 23 пациентов с MSI-позитивными опухолями и 34 больных MSI-негативным РТК. Результаты. В группе больных РТК с MSI-позитивным фенотипом преобладают случаи локализации рака в правой половине ободочной кишки, низкая степень дифференцировки и наличие муцинозного компонента в опухоли (p<0,0001, p=0,005 и p=0,0001 соответственно). У пациентов с MSI-позитивным РТК, содержащим мутацию BRAF, значительно чаще встречается резус-отрицательный фенотип эритроцитов (53,3 % vs 11,8 %, p=0,004). У больных с MSI-позитивными карциномами отмечено увеличение частоты лейкоцитоза (p=0,009) и лимфопении (p=0,014) в периферической крови в предоперационном периоде. Заключение. Повышенная частота резус-негативного фенотипа эритроцитов и изменения в формуле белой крови у пожилых больных РТК с MSI-позитивным фенотипом могут свидетельствовать о роли нарушений иммунной системы в развитии микросателлит-нестабильных карцином

Creating procedures for determining the content of main components in reagents used for synthesizing certified reference materials for composition

Actuality of the research. The need for the development and validation of analysis methods of reagents used for the introduction of elements into reference materials, certified according to the procedure of preparation. The purpose. Development and certification of methods for determining the content of the main component in the reagents used to prepare reference materials. Research methods. Gravimetry, titration, atomic emission spectral analysis with arc excitation, atomic emission spectral analysis with inductively coupled plasma as an excitation source, mass spectral analysis with inductively coupled plasma as ion source. Results. The characteristics of the error of the measurement results are estimated, the Certificates of Attestation of the methods are received, the information is included in the Federal Information Fund