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Search Results: 1 - 10 of 1635 matches for " Maciej Lipko "
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Characteristics of the Alternative Phenotype of Microglia/Macrophages and its Modulation in Experimental Gliomas
Konrad Gabrusiewicz, Aleksandra Ellert-Miklaszewska, Maciej Lipko, Malgorzata Sielska, Marta Frankowska, Bozena Kaminska
PLOS ONE , 2011, DOI: 10.1371/journal.pone.0023902
Abstract: Microglia (brain resident macrophages) accumulate in malignant gliomas and instead of initiating the anti-tumor response, they switch to a pro-invasive phenotype, support tumor growth, invasion, angiogenesis and immunosuppression by release of cytokines/chemokines and extracellular matrix proteases. Using immunofluorescence and flow cytometry, we demonstrate an early accumulation of activated microglia followed by accumulation of macrophages in experimental murine EGFP-GL261 gliomas. Those cells acquire the alternative phenotype, as evidenced by evaluation of the production of ten pro/anti-inflammatory cytokines and expression profiling of 28 genes in magnetically-sorted CD11b+ cells from tumor tissues. Furthermore, we show that infiltration of implanted gliomas by amoeboid, Iba1-positive cells can be reduced by a systematically injected cyclosporine A (CsA) two or eight days after cell inoculation. The up-regulated levels of IL-10 and GM-CSF, increased expression of genes characteristic for the alternative and pro-invasive phenotype (arg-1, mt1-mmp, cxcl14) in glioma-derived CD11b+ cells as well as enhanced angiogenesis and tumor growth were reduced in CsA-treated mice. Our findings define for the first time kinetics and biochemical characteristics of glioma-infiltrating microglia/macrophages. Inhibition of the alternative activation of tumor-infiltrating macrophages significantly reduced tumor growth. Thus, blockade of microglia/macrophage infiltration and their pro-invasive functions could be a novel therapeutic strategy in malignant gliomas.
Inhomogeneous structure of the high-latitude ionosphere as observed at Norilsk
Yu. V. Lipko
Physics , 2001, DOI: 10.1117/12.458490
Abstract: In March and August/September 1995, February 1996, and in March-April 1998, observations of the inhomogeneous structure of the high-latitude ionosphere were carried out at Norilsk (geomagnetic latitude and longitude are 64.2 N and 160.4 E, and L=5.2). Small-scale irregularities (with the lifetime of several seconds,and the spatial scale less than 5-7 km), and medium-size wave irregularities(with the period of 10-50 min, and the horizontal size of tens and hundreds of kilometres) of the ionospheric F layer were investigated under different geophysical conditions. A total of 300 hours of observations was recorded, including 250 reflections from the F2 layer, and the other reflections from the sporadic E layer. The diurnal variations of inhomogeneous structure parameters in March and April is obtained. Dependence of some ionospheric irregularity parameters on geomagnetic activity is presented.
De cómo la biología asume la existencia de razas en el siglo XX
Lipko, Paula;Di Pasquo, Federico;
Scientiae Studia , 2008, DOI: 10.1590/S1678-31662008000200005
Abstract: experiments in biology that examine the existence of racial types seem to have been modulated by human rights movements from middle 20th century. in an attempt to acknowledge this hypothesis we will start our analysis in the 18th century, passing through the 19th century and finally briefly discussing the 20th century general situation. thus, the present work has three main sections. in the first two sections, we will discuss the different forms races were classified and hierarchically ordered in the 19th century. in the third section, we will deal with 20th century problematic, dividing it in three sections. first, we will refer to racial classifications and hierarchical structuring in the first half of the 20th century. then, we will mention the international human rights movement from mid 20th century that objected racial hierarchical structuring. finally, some of the insights that tried to corroborate the existence of races derived from biology will be analyzed. the dissolution of the well versed hierarchy was of supreme importance for the associated social implications. but in spite of these efforts the persistence of racial thought is demonstrated in papers that during the last century tried to acknowledge human diversity.
Antioxidant defence of colostrum and milk in consecutive lactations in sows
Justyna Lipko-Przybylska, Marta Kankofer
Irish Veterinary Journal , 2012, DOI: 10.1186/2046-0481-65-4
Abstract: The activity of antioxidative enzymes and the concentration of vitamin A increased with time postpartum. The concentration of vitamin C was the highest between the 18th and 36th h postpartum.Dynamic changes in the values of antioxidant parameters measured during the study showed that sows milk provides the highest concentration of antioxidants in the 2nd and 3rd and 4th and 5th lactation giving the best defence against reactive oxygen species to newborns and mammary glands.Pregnancy is a period of constant oxidative stress for the dam [1]. Moreover, perinatal stress and the related changes in oxygen partial pressure, may result in the exposition of the newborn to an excess of reactive oxygen species (ROS) during pregnancy, parturition, and postpartum. This happens mainly due to parturition-related alterations in steroid and prostaglandin metabolism in the dam but also due to the change from interauterine to extrauterine environment and the beginning of lung breathing in the newborn [2,3]. An uncontrolled imbalance between the production and neutralization of ROS may cause oxidative stress. It may lead to serious consequences not only for the cell membrane, which can change its permeability, but also for the proper course of metabolic processes, which can be altered due to peroxidative damage of enzymatic proteins and the presence of the toxic products of the peroxidative damage to macromolecules [4]. Antioxidant systems located in all cells and biological fluids protect biologically important proteins and other macromolecules from the peroxidative damage caused by ROS [5].Colostrogenesis starts before parturition and results in production of a thick yellow fluid named colostrum which then accumulates in mammary glands and is secreted by the sows for 2-3 days after parturition [6]. After cessation of the colostrum secretion, it is referred to as mature milk, which differs from colostrum by the concentration of proteins which is due to the decrease in the content of i
Physiological antioxidative/oxidative status in bovine colostrum and mature milk
Kankofer Marta,Lipko-Przybylska Justyna
Acta Veterinaria , 2008, DOI: 10.2298/avb0803231k
Abstract: As colostrum provides the initial substrate supply, of immunological compounds and antioxidants to the neonate, the aim of the present study was to determine the antioxidative/oxidative status of bovine colostrum and milk. Colostrum was collected from healthy dairy cows (n=15) immediately after parturition, 6, 18, 36 h and 7 days later. The total antioxidant capacity (TAC) expressed as μmol/g protein was determined spectrophotometrically at 532 nm based on the reduction of tri-pyridyl-s-triazine (TPTZ). The indirect analysis of the intensity of lipid peroxidation - LPI, (expressed as μmol/g protein), corresponding to oxidation of peroxides, was measured spectrophotometrically at 505 nm. The TAC values have gradually increased from the 6th hour to day 7 (36h vs. 0h and day 7 vs. 0h; p<0.01) and were maximal in mature milk (day 7) (day 7 vs. 36h; p<0.05) whereas LPI values slightly fluctuated within the same period reaching maximal values at 36h (36h vs. 0h, 6h, 18h; p<0.05). In parallel, the ratio TAC/LPI has progressively increased from 71.6 (0h) to 177.6 (day 7). No overall positive correlation between TAC and LPI values was evidenced during the studied period. These results demonstrate dynamic changes of antioxidant systems while LPI remained stable, providing efficient neutralization of radical oxygen species. .
Reversion of Incommensurate Modulation in Cubic Lazurite: Example of Reversible Forced Equilibrium?  [PDF]
Vladimir L. Tauson, Anatoly N. Sapozhnikov, Ekaterina V. Kaneva, Sergei V. Lipko
Natural Resources (NR) , 2014, DOI: 10.4236/nr.2014.512065
Abstract: The sample of cubic lazurite, collected in the Baikal region, with incommensurately 3D modulated (ITM) structure has been studied by the method of high-temperature X-ray powder diffraction. At short time of annealing in high-temperature diffraction experiment the modulation recovery proceeds during cooling down the sample to room temperature. The identity of the period of both initial and recovered modulation demonstrates that the system has a structural memory. The acquired results are interpreted through comparison of thermal behavior of lazurite, sodalite and quartz structures. It is supposed that two kinetically different and thermally activated processes proceed under heating: 1) reversible framework expansion due to Si-O-Al angle increase, and 2) equalizing of periodic local distortions via the diffusion-controlled transfer of cage ions between adjacent subcells. The second process seems to be much slower than the first one, especially at lower temperatures. With increasing temperature, both processes are activated. However, the framework expands more rapidly than the cage clusters migrate, and the periodic distortions of the framework are aligned. Under lower temperatures, the framework shrinks and again accommodates to the configuration of cage cations (clusters), which may be changed at high temperature and sufficient time or may not at lower temperature, short time, unfavorable SO2 fugacity values. In the first case the modulation disappears entirely, while in the second case it arises again. The probable reason for ITM formation is the balance of counteracting energetic terms: the elastic strain energy of structure deformation and the energy of cluster ordering providing the state of forced equilibrium. The excess free energy due to structure distortion is compensated by the increment associated with the cluster ordering process. However, no significant variations in sulphur anion speciation for different degrees of modulation retention were observed by XPS S 2p. This may be due to the ordering of Na- and Ca-containing clusters rather than the clusters with different sulphur species. ITM reversion is considered as an example of reversible forced equilibrium with completely reproducible forcing factor.
Ionospheric manifestations of geomagnetic pulsations at high latitudes
Yu. V. Lipko,A. Yu. Pasinin,R. A. Rakhmatulin
Physics , 2001, DOI: 10.1117/12.458480
Abstract: In this paper the interrelation between geomagnetic pulsations and variations in frequency Doppler shift (Fd) of the ionosphere-reflected radio signal is under investigation. The experiment on simultaneous recording of Fd variations and geomagnetic pulsations was organised at high latitude station in Norilsk (geomagnetic latitude and longitude 64.2 N, 160.4 E, L=5.3) during Febrary-April of 1995-98. Thirty cases of simultaneous recording of duration from 10 min to two hour were analysed: 6 cases of simultaneous recording of variations Fd and regular geomagnetic pulsations Pc5; and 25 cases of recording of Fd variations and irregular pulsations Pi2. On the basis of experimental results, the following conclusions have been drawn: a) Hydromagnetic waves in the range of regular Pc5 pulsations, when interacting with the ionospheric F2 layer, make the main contribution to short-period Fd variations. The possible mechanism of Fd variations are oscillations of electron density, associated with distribution of a hydromagnetic wave in an ionosphere. b) There exists an unquestionable interrelation between Fd variations of the sporadic E layer-reflected radio signal and irregular Pi2 pulsations, but for some reasons it is traced poorly.
Capability of the Free-Ion Eigenstates for Crystal-Field Splitting  [PDF]
Jacek Mulak, Maciej Mulak
Journal of Modern Physics (JMP) , 2011, DOI: 10.4236/jmp.2011.211170
Abstract: Any electronic eigenstate of the paramagnetic ion open-shell is characterized by the three independent multipole asphericities for and 6 related to the second moments of the relevant crystal-field splittings by , where . The Ak as the reduced matrix elements can serve as a reliable measure of the state capability for the splitting produced by the k-rank component of the crystal-field Hamiltonian. These multipolar characteristics allow one to verify any fitted crystal-field parameter set by comparing the calculated second moments and the experimental ones of the relevant crystal-field splittings. We present the multipole characteristics Ak for the extensive set of eigenstates from the lower parts of energy spectra of the tripositive 4 f N ions applying in the calculations the improved eigenfunctions of the free lanthanide ions obtained based on the M. Reid f-shell programs. Such amended asphericities are compared with those achieved for the simplified Russell-Saunders states. Next, they are classified with respect to the absolute or relative weight of Ak in the multipole structure of the considered states. For the majority of the analyzed states (about 80%) the Ak variation is of order of only a few percent. Some essential changes are found primarily for several states of Tm3+, Er3+, Nd3+, and Pr3+ ions. The detailed mechanisms of such Ak changes are unveiled. Particularly, certain noteworthy cancelations as well as enhancements of their magnitudes are explained.
Soy Consumption and Obesity  [PDF]
Dante Roccisano, Maciej Henneberg
Food and Nutrition Sciences (FNS) , 2012, DOI: 10.4236/fns.2012.32038
Abstract: Obesity is now present worldwide, including China, India and developing countries. It now seems no longer acceptable to argue that obesity can simply be explained in terms of caloric consumption only using simple concept of energy in and energy out. There may be specific causes of altered metabolism that produce nutritional imbalances. Individual variation in response to food intake may also be considered. Specific substances in the food chain can influence meta-bolism towards an increase in fat deposits. Xenoestrogens have been suggested to have such an influence. Soy contains phytoestrogens plus phytates, protease inhibitors and other anti-nutrients which block or compromise the body’s uptake of essential vitamins and minerals. This may contribute to nutritional anomalies. We analyzed data from WHO and FAO for 167 countries. These contained percentage of obese individuals (BMI > 30 kg/m2), GDP, caloric consump-tion per capita, and sugar and soy consumption per capita. Regressions and partial correlations were used. Soy con-sumption correlates significantly with levels of obesity, irrespective of GDP and caloric intake. For instance, poor Latin America with soy consumption of 28.9 kg/person/year has more obesity (18.4%) than better off European Union (14.1%) consuming 16.1 kg/person/year of soy. Soy consumption seems to contribute approximately 10% - 21% to the worldwide variation in obesity, depending on the method of statistical analysis. The ubiquitous presence of unfermented soy products in mass produced foods seems to be an important contributor to the obesity epidemic.
Nanoparticle Technology as a Double-Edged Sword: Cytotoxic, Genotoxic and Epigenetic Effects on Living Cells  [PDF]
Mytych Jennifer, Wnuk Maciej
Journal of Biomaterials and Nanobiotechnology (JBNB) , 2013, DOI: 10.4236/jbnb.2013.41008
Abstract: Nanoparticles are considered as powerful tools in nanotechnological applications. Due to their unique physicochemical properties, their interactions with different biological systems have been shown. Nanomaterials have been successfully used as coating materials or treatment and diagnosis tools. Nevertheless, toxic effects of nanoparticles in vitro and in vivo have also been reported. Here, we summarize the current state of knowledge on exposure routes, cellular uptake and toxicological activities of the commonly used nanoparticles. In this context, we discuss the mechanisms of toxicity of nanoparticles involving perturbation of redox milieu homeostasis and cellular signaling pathways.
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