173 research outputs found
Phagocytosis and oxidative activity of neutrophils after interaction with uropathogenic <i>Escherichia coli</i> biofilms
Recurrent urinary tract infections (UTIs) are associated primarily with the ability of Escherichia coli to form biofilms. The interaction of neutrophils, factors of innate immunity, with microorganisms in biofilms is difficult compared to planktonic forms due to the lack of direct contact, as well as due to the antiphagocytic action of the extracellular matrix of biofilms. The purpose of this study was evaluation of neutrophils phagocytic and oxidative activity during interaction with biofilms of uropathogenic E. coli (UPEC) DL82 and R44. Peripheral blood neutrophils from healthy men were isolated using ficoll-urographin double gradient, incubated for 1 h with bacterial cells from biofilms or their supernatants, then leukocytes functional activity was evaluated. Phagocytic activity of neutrophils was determined by the degree of bioluminescence inhibition of bioluminescent strain E. coli K12 TG1 lux+ (pXen) upon their absorption by neutrophils. Production of extracellular reactive oxygen species (ROS) was analyzed by the intensity of luminol-dependent chemiluminescence in spontaneous and stimulated by E. coli K12 variants. Significance of differences was determined using Student’s t-test at p < 0.05. It was found that neutrophils interaction with UPEC biofilm cells or supernatants did not affect the phagocytic activity. E. coli DL82 supernatants reduce neutrophils spontaneous ROS production compared to control and biofilm cells. E. coli R44 supernatants with a low virulence potential did not affect ROS production, while biofilm cells stimulated it. When assessing stimulated ROS production, exposure to R44 strain supernatants did not cause a decrease in neutrophils activation in response to an external stimulus (E. coli K12 cells). Preliminary contact of neutrophils with E. coli R44 bacteria resulted in a high and prolonged level of ROS production compared to the control. Neutrophils interaction with DL82 cells resulted in a higher level of ROS compared to supernatants, however a subsequent rapid depletion of neutrophils oxidative potential was observed. Thus, cells and supernatants of UPEC biofilms can determine the activation of neutrophils
Melatonin in Th17/Treg differentiation: the contribution of the hormone's own production by T lymphocytes
The hormone melatonin is involved in regulation of functioning of almost all organs and systems of the organism. In the immune system, T lymphocytes are an important target of melatonin: they express specific melatonin receptors with different affinities – membrane MT1 and MT2 and nuclear RORa, as well as intracellular molecules that nonspecifically bind melatonin at high concentrations. Moreover, many in vitro studies reveal their own production of melatonin by T lymphocytes in response to polyclonal activation and its involvement as autocrine or paracrine factor in the induction of IL-2 and IL-2 receptor (IL-2R) synthesis by T cells, with melatonin receptors involvement in implementation of these effects. Since IL-2/IL-2R-dependent signal is a key event in T lymphocytes proliferative response induction, intrinsic melatonin seems to be directly involved at least in the clonal expansion of these cells. In this work, we investigated the contribution of T cells’ melatonin to regulation of the next stage of T lymphocyte activation, namely, the differentiation of T helper populations Th17 and Treg. It was shown that blockade of both membrane and nuclear melatonin receptors did not cause statistically significant changes in Th17 differentiation, although the trend was fixed for a decrease. Simultaneously, CD4+FoxP3+Т cells level decreased under the nonselective blockade of membrane hormone receptors, and Treg-associated cytokine TGF-b concentration in activated cultures supernatants decreased both in case of MT1/MT2 nonselective blockade and MT2 selective blockade. The data indicate that melatonin produced by T lymphocytes in culture can contribute to the control of naive CD4+T cell differentiation into Treg in vitro, and the hormone effects are mediated by membrane melatonin receptors. The presence of a large number targets with different affinities for melatonin in T lymphocytes determines the key role of the hormone concentration in its effects on these cells. And when interpreting data on melatonin-dependent regulation of Treg, it is important to take into account the hormone’s own production by lymphocytes, since T cells’ melatonin can mask the exogenous hormone effects or interfere with its action due to competitive binding to hormone receptors
Соntent of the heavy metal in the organism of brown frogs of the city zone of Kiev
Досліджено рівні накопичення та розподілу важких металів (Pb, Cd, Zn, Cu, Cr) в органах та тканинах двох видів жаб (Rana temporaria та R. arvalis) із біотопів, безпосередньо прилеглих до деяких водойм міської зони Києва.Исследованы уровни накопления и распределения тяжелых металлов (Pb, Cd, Zn, Cu, Cr) в органах и тканях двух видов лягушек (Rana temporaria и R. arvalis) из биотопов, непосредственно прилегающих к некоторым водоемов городской зоны Киева.The content and distribution of heavy metals (Pb, Cd, Zn, Cu, Cr) in organs and tissues of Rana temporaria and R. arvalis from biotopes near some reservoirs in the city zone of Kyiv are studied
Developing a modern thermal strengthening technique for regulated fishplate cooling
A modern ecologically friendly technique for fishplate (joint bar) thermal strengthening by regulated water cooling is proposed. The proposed technique can successfully replace the conventional one - oil quenching - due to making the cooling process more controlled by obtaining a uniform temperature distribution over fishplate elements with a different mass such as heads and the wet. The oil quenching process is an out of control fire hazardous one and requires controlling the permanent cooling capability, fishplate flushing after the operation. It is necessary to utilize the oil and to have a special ventilation system. As a mineral oil substitute, the usage of polymer media has been investigated. Within the time, the polymer solution needs to be recycled; the high cost of polymer concentrates also plays an important role. Quenching by water spraying is the most ecological and controlled type of thermal strengthening. The technique was validated by a test bench experiment and implemented in the metallurgical industry. The mechanical properties have been obtained to meet the GOST 4133-73 technical requirements. Moreover, the analysis made showed that when the controlled cooling device is fitted into the line existing due to exclusion of the hardening tank and washing machine from the processing flow it is possible to save energy, exclude the expenditures for acquisition, the preparation of oil and washing mixtures as well as for regeneration of the oils used and washing solutions. © 2014 WIT Press.International Journal of Safety and Security Engineering;International Journal of Sustainable Development and Planning;WIT Transactions on Ecology and the Environmen
Microstructure and electrical properties of thin SiC films on Si substrates of p- and n-types
Cryptic Diversity in Paramecium multimicronucleatum Revealed with a Polyphasic Approach
Paramecium (Ciliophora) systematics is well studied, and about twenty morphological species have been described. The morphological species may include several genetic species. How-ever, molecular phylogenetic analyses revealed that the species diversity within Paramecium could be even higher and has raised a problem of cryptic species whose statuses remain uncertain. In the present study, we provide the morphological and molecular characterization of two novel Paramecium species. While Paramecium lynni n. sp., although morphologically similar to P. multimicronucleatum, is phylogenetically well separated from all other Paramecium species, Paramecium fokini n. sp. appears to be a cryptic sister species to P. multimicronucleatum. The latter two species can be distinguished only by molecular methods. The number and structure of micronuclei, traditionally utilized to discriminate species in Paramecium, vary not only between but also within each of the three studied species and, thus, cannot be considered a reliable feature for species identification. The geographic distribution of the P. multimicronucleatum and P. fokini n. sp. strains do not show defined patterns, still leaving space for a role of the geographic factor in initial speciation in Paramecium. Future findings of new Paramecium species can be predicted from the molecular data, while morphological characteristics appear to be unstable and overlapping at least in some species
Нутритивный статус пациентов в длительном критическом состоянии
Material and methods. We examined 23 patients with chronic critical illness who were in a minimally conscious state (MCS) with 10.9±2.5 scores on the FOUR (Full Outline of Unresponsiveness) Score Coma Scale. Indicators of carbohydrate, lipid, protein and energy exchange metabolism were evaluated using specimens sampled in the morning hours. Nutritional support was provided by isocaloric isonitrogenic mixtures.Results. Blood biochemistry showed decreases in total protein and albumin levels in 86.9% and 91.3% of patients, respectively. The tests also revealed decreased concentrations of several amino acids, including essential amino acids: histidine (38.3±13.07 µmol/l), methionine (12.68±3.81 µmol/l), threonine (61.6 [58.5;87.7] µmol/l), tryptophan (33.06±15.95 µmol/l), and non-essential amino acids: arginine (40.50 [22.2; 46.9] µmol/l), glutamic acid (124.5±39.29 µmol/l), tyrosine (37.97±10.12 µmol/l). Some correlations between the concentrations of individual amino acids and other indicators were revealed, such as histidine and CRP (r=–0.68, P=0.043), tryptophan and CRP (r=–0.86, P=0.002), histidine and leukocyte count (r=–0.76, P=0.015), methionine and lysine (r=0.88, P=0.008), methionine and patient's weight (r=–0.68, P=0.042). A relationship between threonine concentration and the level of consciousness on the FOUR scale (r=–0.73, P=0.037) was also found. All patients demonstrated significant alterations of carbohydrate and lipid metabolism.Conclusion. Alteration of adequate protein metabolism seems to be the most affected constituent in the nutritional status of patients with chronic critical illness. It is manifested by a decrease in the concentration of total protein and a number of essential and non-essential amino acids, which implies the importance of highprotein nutritional support and correction of the amino acid profile. Цель. Оценить состояние нутритивного статуса пациентов в длительном критическом состоянииМатериал и методы. Обследовали 23 пациента в длительном критическом состоянии, находящихся в минимальном сознании по шкале FOUR (Full Outline of Unresponsiveness), уровень сознания — 10,9±2,5 балла. Оценили показатели углеводного, жирового и белкового обмена, а также энергообмена, забор анализов осуществляли в утренние часы. Нутритивную поддержку обеспечивали изокалорическими изонитрогенными смесями.Результаты. В биохимических показателях крови у 86,9% пациентов выявили сниженное содержание общего белка, у 91,3% — альбумина. При этом отметили также снижение концентрации ряда аминокислот: среди незаменимых — гистидина 38,3±13,07 мкмоль/л, метионина 12,68±3,81 мкмоль/л, треонина 61,6 [58,5; 87,7] мкмоль/л, триптофана 33,06±15,95 мкмоль/л, а среди заменимых — аргинина 40,50 [22,2; 46,9] мкмоль/л, глутаминоваой кислоты 124,5±39,29 мкмоль/л и тирозина 37,97±10,12 мкмоль/л. Выявили корреляционные связи между содержанием некоторых аминокислот и другими показателями пациентов: между концентрацией гистидина и содержанием СРБ (r=–0,68, p=0,043), а также между концентрациями триптофана и СРБ (r =–0,86, p=0,002), концентрацией гистидина и количеством лейкоцитов (r=–0,76, p=0,015), концентрацией метионина и лизином (r=0,88, p=0,008), концентрацией метионина и весом пациента (r=0,68, p=0,042), и связь между концентрацией треонина и уровнем сознания по шкале FOUR (r=–0,73, p=0,037). Выраженных нарушений углеводного и жирового обмена не отметили.Заключение. Установили, что у пациентов в длительном критическом состоянии наиболее страдающим участком нутритивного статуса является нарушение адекватного белкового обмена. Оно проявляется снижением концентрации белка и ряда заменимых и незаменимых аминокислот, что предполагает важность высокобелковой нутритивной поддержки и коррекции аминокислотного профиля.
TELECOMMUNICATION TECHNOLOGIES FOR MONITORING OF FUNCTIONAL STATUS OF DRIVERS DURING THEIR WORK
The article is devoted to development of modern telemetric methods for an on-line evaluation of functional status of vehicle drivers during their work. The study of occupational load effect on cardiovascular system was performed with the use of mobile devices included portable sensors and storage device to collect information (smartphone). The developed computer programs were used to calculate spectral indices of heart rhythm variability (HRV). A high self-descriptiveness of wavelet transform for identification offunctional status of cardiovascular system was shown. The reduction of HRV, increase of sympathetic component in regulation and increase of vegetative balance index were observed in drivers by fatigue. The intensity of HRV changes met with occupational load level and characterized degree of individual response as well as allowed to detect exposure induced the stress. A wireless cardiorhythmography is a perspective method for creating personal monitoring system for increasing quality of the drivers' life andfor their health preservation
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