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Search Results: 1 - 10 of 179 matches for " Elzbieta Pyza "
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The Clock Input to the First Optic Neuropil of Drosophila melanogaster Expressing Neuronal Circadian Plasticity
Milena Damulewicz, Elzbieta Pyza
PLOS ONE , 2011, DOI: 10.1371/journal.pone.0021258
Abstract: In the first optic neuropil (lamina) of the fly's visual system, two interneurons, L1 and L2 monopolar cells, and epithelial glial cells show circadian rhythms in morphological plasticity. These rhythms depend on clock gene period (per) and cryptochrome (cry) expression. In the present study, we found that rhythms in the lamina of Drosophila melanogaster may be regulated by circadian clock neurons in the brain since the lamina is invaded by one neurite extending from ventral lateral neurons; the so-called pacemaker neurons. These neurons and the projection to the lamina were visualized by green fluorescent protein (GFP). GFP reporter gene expression was driven by the cry promotor in cry-GAL4/UAS-GFP transgenic lines. We observed that the neuron projecting to the lamina forms arborizations of varicose fibers in the distal lamina. These varicose fibers do not form synaptic contacts with the lamina cells and are immunoreactive to the antisera raised against a specific region of Schistocerca gregaria ion transport peptide (ITP). ITP released in a paracrine way in the lamina cortex, may regulate the swelling and shrinking rhythms of the lamina monopolar cells and the glia by controlling the transport of ions and fluids across cell membranes at particular times of the day.
Circadian Regulation of the Na+/K+-Atpase Alpha Subunit in the Visual System Is Mediated by the Pacemaker and by Retina Photoreceptors in Drosophila Melanogaster
Milena Damulewicz, Ezio Rosato, Elzbieta Pyza
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0073690
Abstract: We investigated the diurnal oscillation in abundance of the catalytic α subunit of the sodium/potassium pump (ATPα) in the brain of Drosophila melanogaster. This rhythm is bimodal and is particularly robust in the glia cells of the lamina, the first optic neuropil. We observed loss of ATPα cycling in lamina glia in behaviourally arrhythmic per01 and tim01 mutants and in flies overexpressing the pro-apoptotic gene hid in the PDF-positive clock neurons. Moreover, the rhythm of ATPα abundance was altered in cry01 and Pdf0 mutants, in flies with a weakened clock mechanism in retina photoreceptor cells and in those subject to downregulation of the neuropeptide ITP by RNAi. This complex, rhythmic regulation of the α subunit suggests that the sodium/potassium pump may be a key target of the circadian pacemaker to impose daily control on brain activities, such as rhythmic changes in neuronal plasticity, which are best observed in the visual system.
Fear Learning Increases the Number of Polyribosomes Associated with Excitatory and Inhibitory Synapses in the Barrel Cortex
Malgorzata Jasinska, Ewa Siucinska, Ewa Jasek, Jan A. Litwin, Elzbieta Pyza, Malgorzata Kossut
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0054301
Abstract: Associative fear learning, resulting from whisker stimulation paired with application of a mild electric shock to the tail in a classical conditioning paradigm, changes the motor behavior of mice and modifies the cortical functional representation of sensory receptors involved in the conditioning. It also induces the formation of new inhibitory synapses on double-synapse spines of the cognate barrel hollows. We studied density and distribution of polyribosomes, the putative structural markers of enhanced synaptic activation, following conditioning. By analyzing serial sections of the barrel cortex by electron microscopy and stereology, we found that the density of polyribosomes was significantly increased in dendrites of the barrel activated during conditioning. The results revealed fear learning-induced increase in the density of polyribosomes associated with both excitatory and inhibitory synapses located on dendritic spines (in both single- and double-synapse spines) and only with the inhibitory synapses located on dendritic shafts. This effect was accompanied by a significant increase in the postsynaptic density area of the excitatory synapses on single-synapse spines and of the inhibitory synapses on double-synapse spines containing polyribosomes. The present results show that associative fear learning not only induces inhibitory synaptogenesis, as demonstrated in the previous studies, but also stimulates local protein synthesis and produces modifications of the synapses that indicate their potentiation.
Side effects of selection for body weigh in laboratory mice
Elzbieta Michalsk?
Genetics Selection Evolution , 1978, DOI: 10.1186/1297-9686-10-4-605b
Abstract:
Supercapacitors based on carbon materials and ionic liquids
Frackowiak, Elzbieta;
Journal of the Brazilian Chemical Society , 2006, DOI: 10.1590/S0103-50532006000600003
Abstract: this paper presents performance of supercapacitor built from different carbon materials. the general principle of supercapacitor and formula connected with its operation are also described. the role of carbon nanotexture has been underlined selecting carbons prepared by template techniques. it has been demonstrated that mainly micropores and small mesopores play important role for charging of electrical double layer, however, interconnectivity of pores is crucial for charge propagation. the presence of heteroatom, e.g. nitrogen in the carbon network is profitable because of additional reversible faradaic reactions. a linear dependence of capacitance values vs nitrogen content has been found. ionic liquids are presently considered as a novel generation of electrolyte with interesting properties, e.g. a high operating voltage. an increase of supercapacitor voltage (over 3v) has been realized by application of ionic liquids based on phosphonium salt.
Photoemission of 4f and 5f systems
Elzbieta Guziewicz
Optica Applicata , 2006,
Abstract: Photoemission studies provide an extensive insight into the electronic structure and are crucial for comprehension of the wide range of ground state properties found in lanthanide and actinide materials. This paper reviews different techniques used in photoemission experiments with respect to investigation of such specific aspects of the electronic structure of 4f and 5f systems as mixed valence, localization of 4f electron shell, and dual character of the 5f electrons. Photoemission results on lanthanide and actinide systems are also presented.
Resident Tissue Leukocytes: Underappreciated Guards of the Body
Elzbieta Kolaczkowska
Open Journal of Hematology , 2010,
Abstract: Inflammatory reactions occurring in different milieu follow common phases with major highlights being local changes in vascular permeability and influx of inflammatory leukocytes that eliminate the source of inflammation while subsequent resolution is completed by tissue repair. The main inflammatory cells consist of blood-derived neutrophils and macrophages that arrive to the inflammatory site in response to a chemotactic signal. However, their arrival to the loci is initiated by a special set of leukocytes already present in various places of the body such as skin or body cavities that are called tissue or resident leukocytes. The cells consist of mast cells, macrophages and lymphocytes. Although the presence of resident leukocytes is commonly recognized their actual involvement in subsequent stages of inflammation is underappreciated while the cells are critical for all phases of the reaction. The current mini-review describes the role of resident leukocytes in the initiation, the course, and the termination of exemplary acute inflammatory reaction, namely zymosan-induced peritonitis. Additionally, facts on human resident peritoneal leukocytes are presented and discussed.
ABRAMOWSKI AND BAKUNIN – TWO CONCEPTIONS OF LIBERTY
Elzbieta Podgorska
Studia Humanistyczne (Kraków. 2003) , 2008,
Abstract: Two ways to emancypation of mankind: Bakunin’s by revolution and Abramowski’sby evolution; the second way basing on education and moral developing of people.That two methods join critical estimation of state, religion and one purpose: to createnew, justice political system supportrd on only one level form of framework.These philosophers unite realistit condemnation of political and economic actualityand utopian solutions – the last supported on a belief that a man has only a good dispositions.
The activity of enzymes can be modified by homeopathic dilutions of their effectors
Elzbieta Malarczyk
International Journal of High Dilution Research , 2012,
Abstract: Introduction: The fungal and bacterial materials are very useful for testing the influence of low and very low doses of low molecular phenolic effectors on enzymatic system of phenoloxidases when they are incubated together in the reaction space. Aim: Searching for the model useful biological systems to study the action of diluted low molecular substances on living organisms, which is based on common physical and biochemical analytical procedures. Methods: The fungal and actinomycetal bacterial materials from laboratory cultures as a source of common phenoloxidases, laccase, peroxidase and O-demethylase as well as the pure plant peroxidase were used in experiments described earlier [1-5]. Subsequent dilutions of low molecular phenolic metabolites, appropriate for studied enzymatic systems, prepared in 75% ethanol in the proportion of 1:100 (centesimal) and dynamized by shaking in accordance with homeopathic procedures were prepared in our laboratory. During experiments with bacterial and fungal materials and a pure plant peroxidase, which were incubated together with subsequent dilutions of proper phenolic effector, different analytic methods were used including a gel (PAGE) [4] and capillary (MEKCE) electrophoresis [5], spectral and colorimetric methods [1,2,3] as well as the electron microscopy [5]. Results: In the light of presented data [1-5], the incubation of biological material with diluted phenolic effectors induces various effects on tested enzyme activity. It changed in sinusoidal manner with an gradual growth of dilution rate of tested effectors, which was distinctly visible on the diagram when the number of dilutions was localized on abscissa and biological activity on the ordinate. Exemplary results of the chosen experiments will be presented. For tested enzymes: laccase, peroxidase and O-demethylase, the distance between maximal points of enzymatic activity, shown on a sine curve, repeats more often every 10 subsequent centesimal dilutions. Along with the extension of incubation period the displacement of maximal and minimal points on curve were noticed, which revealed a dynamic aspect of studied phenomenon. Conclusions: Fungal and bacterial cells seem to be a very convenient material for studying the action of diluted metabolites on enzymatic systems because their popular presence in environment. Results of all experiments confirmed the same nature of the mentioned observations. Because other authors had similar conclusion concerning human [6,7] and plant materials [8,9], the described relations seem to be common in natural world. It coul
Kinetic changes in activity of HR-peroxidase, induced by very low doses of phenol Cambios cin ticos en la actividad de la HR-peroxidasa inducidos por dosis muy bajas de fenol Mudan §as cin ticas na atividade da HR-peroxidade induzidas por doses muito baixas de fenol
Elzbieta Malarczyk
International Journal of High Dilution Research , 2008,
Abstract: The allosteric protein of horseradish peroxidase (HRP) shows two main types of activity, peroxidase and oxidase, depending on the kind of low molecular effectors. The effects of very low doses of phenol, prepared by successive dilutions in water or in 75% ethanol, on initial HRP activity in oxidation of o-dianisidine or luminol were tested in a systematic manner by colorimetric and luminometric methods. Results showed that phenol dilutions, including those below Avogadro ¢a a ¢s number, could activate or inhibit HRP in peroxidase and oxidase type reactions with a sinusoidal pattern. Km values for the studied substrates changed parallel to HRP peroxidase/oxidase activity and the maximum activity in the peroxidase reaction corresponded to the minimum activity in the oxidase reaction and vice versa. The effect also depended on the type of dilutor. The observations of the peroxidase/oxidase oscillations in the sinusoidal pattern of HRP activity, dependent on the rate of phenol dissolution and the time of preincubation, point out to the conclusion that HRP might be a good model for high dilutions research. The experiments provide strong evidence that horseradish peroxidase (HRP) is a very sensitive detector of subtle changes in the concentration of phenol used as a cofactor in the peroxidase/oxidase reaction. Keywords: HR-peroxidase, peroxidase-oxidase, phenol, hormesis, homeopathy, high dilutions. Mudan §as cin ticas na atividade da HR-peroxidade induzidas por doses muito baixas de fenol Resumo A prote -na alost rica da peroxidase do rabano (HRP) mostra dois tipos principais de atividade, peroxidase e oxidase, de acordo com o tipo de efetores de baixa molecularidade. Os efeitos de doses muito baixas de fenol, preparadas atrav s de dilui § μes sucessivas em gua ou etanol 75% na atividade inicial da HRP sobre a oxida § £o da o-dianisidina ou luminol for testados de modo sistem tico atrav s de m todos colorim tricos e luminom tricos. Os resultados mostram que as dilui § μes de fenol, incluindo aquelas por baixo do n omero de Avogadro, foram capazes de ativar ou inibir a HRP em rea § μes de tipo peroxidade e oxidase com um padr £o sinusoidal. os valores Km dos substratos estudados variaram paralelamente atividade peroxidase/oxidase da HRP; a atividade m xima da rea § £o peroxidase correspondeu atividade m -nima na rea § £o oxidase e vice-versa. O efeito tamb m se mostrou dependente do tipo do solvente. A observa § £o das oscila § μes sinusoidais na atividade da HRP, depen
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