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Vendelin Francisc GLAZER
Revista de Administratie Publica si Politici Sociale , 2010,
Abstract: The Maastricht Treaty establishes the objectives and the competences of the European Union. TheEU has certain objectives: constantly developing a stronger union of the European countries andthe promotion of economical progress and social balance, especially by creating a space with nointernal crossing border, by strengthening the economical and social connection and by creatingthe Monetary and Economical Union, affirming its identity on an international scale, by a commondefense community, strengthening the protection of citizen’s interests and rights, developing anamassed cooperation in the juridical and internal businesses.
Vendelin Francisc GLAZER
Revista de Administratie Publica si Politici Sociale , 2011,
Abstract: This article aims at capturing the administrative changes occurred in Romania in the periodbetween 1998-2007 because of the internal reforms of democratization supported, actually, by theEuropean Union. The ground hypothesis is that the EU is responsible" for the Romanianadministrative reforms undergone in the period under review. Why? Because Romania became anofficial membership candidate and the Union required its candidates to harden their administrationin order to take over the Community legislation. The “suspect" was confirmed finally, the Unionbeing the only one "to blame" for the Romanian administrative changes during 1998-2007 periodand the urge” was the need to get in line with the organization and operation manner of theEuropean Union state members’ administration and with the Union itself.
Symbolic flux analysis for genome-scale metabolic networks
David W Schryer, Marko Vendelin, Pearu Peterson
BMC Systems Biology , 2011, DOI: 10.1186/1752-0509-5-81
Abstract: A symbolic Gauss-Jordan elimination routine was developed for analyzing large metabolic networks. This routine was tested by finding the steady state solutions for a number of curated stoichiometric matrices with the largest having about 4000 reactions. The routine was able to find the solution with a computational time similar to the time used by a numerical singular value decomposition routine. As an advantage of symbolic solution, a set of independent fluxes can be suggested by the researcher leading to the formation of a desired flux basis describing the steady state solution of the network. These independent fluxes can be constrained using experimental data. We demonstrate the application of constraints by calculating a flux distribution for the central metabolic and amino acid biosynthesis pathways of yeast.We were able to find symbolic solutions for the steady state flux distribution of large metabolic networks. The ability to choose a flux basis was found to be useful in the constraint process and provides a strong argument for using symbolic Gauss-Jordan elimination in place of singular value decomposition.The explosion of tools available to simulate the systems level properties of biological systems is indicative of the wide scale uptake of integrative biology. The Systems Biology Markup Language (SBML) Web site [1] now lists over 200 packages that make use of their library. This large number of tools reflects both the wide variety and abundance of biological data now available to constrain biological models as well as the large variety of simplifying assumptions made to gain insight from this plethora of data.At the core of many of these analytical tools is the strict requirement of conservation of mass for each biological transformation. Because models of metabolic systems are typically under-determined, a common task when analyzing them is to find all possible steady state regimes when the concentrations of each metabolite do not change appreciably with
Intracellular diffusion restrictions in isolated cardiomyocytes from rainbow trout
Niina Sokolova, Marko Vendelin, Rikke Birkedal
BMC Cell Biology , 2009, DOI: 10.1186/1471-2121-10-90
Abstract: Trout cardiomyocytes hypercontracted in the solutions used for mammalian cardiomyocytes. We developed a new solution in which they retained their shape and showed stable steady state respiration rates throughout an experiment. The apparent ADP-affinity of permeabilized cardiomyocytes was different from that of fibers. It was higher, independent of temperature and not increased by creatine. However, it was still about ten times lower than in isolated mitochondria.The differences between fibers and cardiomyocytes suggest that results from trout heart fibers were affected by incomplete separation of the cells. However, the lower ADP-affinity of cardiomyocytes compared to isolated mitochondria indicate that intracellular diffusion restrictions are still present in trout cardiomyocytes despite their lower density of intracellular membrane structures. The lack of a creatine effect indicates that trout heart lacks mitochondrial creatine kinase tightly coupled to respiration. This argues against diffusion restriction by the outer mitochondrial membrane. These results from rainbow trout cardiomyocytes resemble those from other low-performance hearts such as neonatal rat and rabbit hearts. Thus, it seems that metabolic regulation is related to cardiac performance, and it is likely that rainbow trout can be used as a model animal for further studies of the localization and role of diffusion restrictions in low-performance hearts.In permeabilized preparations of mammalian oxidative muscles such as red skeletal muscle and the heart, diffusion of ADP and phosphate from the surrounding medium to the adenine nucleotide translocase (ANT) in the inner mitochondrial membrane is restricted [1,2]. Especially the diffusion restriction of ADP in adult rat cardiomyocytes has received much attention, because the compromised energetic balance induced by ischemia-reperfusion damage is associated with diminished diffusion restrictions [3,4].The existence of diffusion restrictions is indicated
The effect of femoral and popliteal percutaneous transluminal balloon angioplasty on patients' quality of life
Slovacek, Ladislav;Slovackova, Birgita;Chovanec, Vendelin;
Sao Paulo Medical Journal , 2007, DOI: 10.1590/S1516-31802007000400012
Abstract: context and objective: peripheral arterial occlusive disease (paod) is a prevalent atherosclerotic disorder characterized by limb pain on exertion, limb loss and a high mortality rate. because of its chronic nature, it often has a negative impact on patients' quality of life (qol). this study aimed to assess qol among patients with paod that was treated by endovascular intervention using femoral and popliteal percutaneous transluminal balloon angioplasty (ptba). design and setting: this study was local, prospective and longitudinal. it was carried at the second department of internal medicine of charles university hospital in hradec kralove, czech republic. methods: thirty paod patients (20 male and 10 female) were treated by endovascular intervention using femoral and popliteal ptba. the czech version of the international generic european quality of life questionnaire (eq-5d) was applied. results: the statistical evaluation demonstrated that qol presented highly significant statistical dependence on femoral and popliteal ptba (p < 0.0001). conclusion: the results showed that femoral and popliteal ptba had a highly positive effect on the qol of patients with paod.
Bidirectionality and Compartmentation of Metabolic Fluxes Are Revealed in the Dynamics of Isotopomer Networks
David W. Schryer,Pearu Peterson,Toomas Paalme,Marko Vendelin
International Journal of Molecular Sciences , 2009, DOI: 10.3390/ijms10041697
Abstract: Isotope labeling is one of the few methods of revealing the in vivo bidirectionality and compartmentalization of metabolic fluxes within metabolic networks. We argue that a shift from steady state to dynamic isotopomer analysis is required to deal with these cellular complexities and provide a review of dynamic studies of compartmentalized energy fluxes in eukaryotic cells including cardiac muscle, plants, and astrocytes. Knowledge of complex metabolic behaviour on a molecular level is prerequisite for the intelligent design of genetically modified organisms able to realize their potential of revolutionizing food, energy, and pharmaceutical production. We describe techniques to explore the bidirectionality and compartmentalization of metabolic fluxes using information contained in the isotopic transient, and discuss the integration of kinetic models with MFA. The flux parameters of an example metabolic network were optimized to examine the compartmentalization of metabolites and and the bidirectionality of fluxes in the TCA cycle of Saccharomyces uvarum for steady-state respiratory growth.
Sensitivity Analysis of Flux Determination in Heart by H218O -provided Labeling Using a Dynamic Isotopologue Model of Energy Transfer Pathways
David W. Schryer,Pearu Peterson,Ardo Illaste,Marko Vendelin
PLOS Computational Biology , 2012, DOI: 10.1371/journal.pcbi.1002795
Abstract: To characterize intracellular energy transfer in the heart, two organ-level methods have frequently been employed: inversion and saturation transfer, and dynamic labeling. Creatine kinase (CK) fluxes obtained by following oxygen labeling have been considerably smaller than the fluxes determined by saturation transfer. It has been proposed that dynamic labeling determines net flux through CK shuttle, whereas saturation transfer measures total unidirectional flux. However, to our knowledge, no sensitivity analysis of flux determination by oxygen labeling has been performed, limiting our ability to compare flux distributions predicted by different methods. Here we analyze oxygen labeling in a physiological heart phosphotransfer network with active CK and adenylate kinase (AdK) shuttles and establish which fluxes determine the labeling state. A mathematical model consisting of a system of ordinary differential equations was composed describing enrichment in each phosphoryl group and inorganic phosphate. By varying flux distributions in the model and calculating the labeling, we analyzed labeling sensitivity to different fluxes in the heart. We observed that the labeling state is predominantly sensitive to total unidirectional CK and AdK fluxes and not to net fluxes. We conclude that measuring dynamic incorporation of into the high-energy phosphotransfer network in heart does not permit unambiguous determination of energetic fluxes with a higher magnitude than the ATP synthase rate when the bidirectionality of fluxes is taken into account. Our analysis suggests that the flux distributions obtained using dynamic labeling, after removing the net flux assumption, are comparable with those from inversion and saturation transfer.
ADP Protects Cardiac Mitochondria under Severe Oxidative Stress
Niina Sokolova, Shi Pan, Sarah Provazza, Gisela Beutner, Marko Vendelin, Rikke Birkedal, Shey-Shing Sheu
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0083214
Abstract: ADP is not only a key substrate for ATP generation, but also a potent inhibitor of mitochondrial permeability transition pore (mPTP). In this study, we assessed how oxidative stress affects the potency of ADP as an mPTP inhibitor and whether its reduction of reactive oxygen species (ROS) production might be involved. We determined quantitatively the effects of ADP on mitochondrial Ca2+ retention capacity (CRC) until the induction of mPTP in normal and stressed isolated cardiac mitochondria. We used two models of chronic oxidative stress (old and diabetic mice) and two models of acute oxidative stress (ischemia reperfusion (IR) and tert-butyl hydroperoxide (t-BH)). In control mitochondria, the CRC was 344 ± 32 nmol/mg protein. 500 μmol/L ADP increased CRC to 774 ± 65 nmol/mg protein. This effect of ADP seemed to relate to its concentration as 50 μmol/L had a significantly smaller effect. Also, oligomycin, which inhibits the conversion of ADP to ATP by F0F1ATPase, significantly increased the effect of 50 μmol/L ADP. Chronic oxidative stress did not affect CRC or the effect of 500 μmol/L ADP. After IR or t-BH exposure, CRC was drastically reduced to 1 ± 0.2 and 32 ± 4 nmol/mg protein, respectively. Surprisingly, ADP increased the CRC to 447?± 105 and 514?± 103 nmol/mg protein in IR and t-BH, respectively. Thus, it increased CRC by the same amount as in control. In control mitochondria, ADP decreased both substrate and Ca2+-induced increase of ROS. However, in t-BH mitochondria the effect of ADP on ROS was relatively small. We conclude that ADP potently restores CRC capacity in severely stressed mitochondria. This effect is most likely not related to a reduction in ROS production. As the effect of ADP relates to its concentration, increased ADP as occurs in the pathophysiological situation may protect mitochondrial integrity and function.
Tight Coupling of Na+/K+-ATPase with Glycolysis Demonstrated in Permeabilized Rat Cardiomyocytes
Mervi Sepp, Niina Sokolova, Svetlana Jugai, Merle Mandel, Pearu Peterson, Marko Vendelin
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0099413
Abstract: The effective integrated organization of processes in cardiac cells is achieved, in part, by the functional compartmentation of energy transfer processes. Earlier, using permeabilized cardiomyocytes, we demonstrated the existence of tight coupling between some of cardiomyocyte ATPases and glycolysis in rat. In this work, we studied contribution of two membrane ATPases and whether they are coupled to glycolysis - sarcoplasmic reticulum Ca2+ ATPase (SERCA) and plasmalemma Na+/K+-ATPase (NKA). While SERCA activity was minor in this preparation in the absence of calcium, major role of NKA was revealed accounting to ~30% of the total ATPase activity which demonstrates that permeabilized cell preparation can be used to study this pump. To elucidate the contribution of NKA in the pool of ATPases, a series of kinetic measurements was performed in cells where NKA had been inhibited by 2 mM ouabain. In these cells, we recorded: ADP- and ATP-kinetics of respiration, competition for ADP between mitochondria and pyruvate kinase (PK), ADP-kinetics of endogenous PK, and ATP-kinetics of total ATPases. The experimental data was analyzed using a series of mathematical models with varying compartmentation levels. The results show that NKA is tightly coupled to glycolysis with undetectable flux of ATP between mitochondria and NKA. Such tight coupling of NKA to PK is in line with its increased importance in the pathological states of the heart when the substrate preference shifts to glucose.
The asthma candidate gene NPSR1 mediates isoform specific downstream signalling
Christina Pietras, Johanna Vendelin, Francesca Anedda, Sara Bruce, Mikael Adner, Lilli Sundman, Ville Pulkkinen, Harri Alenius, Mauro D'Amato, Cilla S?derh?ll, Juha Kere
BMC Pulmonary Medicine , 2011, DOI: 10.1186/1471-2466-11-39
Abstract: HEK-293 cells transiently overexpressing NPSR1-A or NPSR1-B were stimulated with the ligand neuropeptide S (NPS) and downstream signalling effects were monitored by genome-scale affymetrix expression-arrays. The results were verified by NPS concentration-response and time series analysis using qRT-PCR, cAMP and Ca2+ assays, and cAMP/PKA, MAPK/JNK and MAPK/ERK pathway specific reporter assays.NPSR1-B signalled through the same pathways and regulated the same genes as NPSR1-A, but NPSR1-B yielded lower induction on effector genes than NPSR1-A, with one notable exception, CD69, a marker of regulatory T cells.We conclude that NPSR1-B is regulating essentially identical set of genes as NPSR1-A, with few, but possibly important exceptions, and that NPSR1-A induces stronger signalling effects than NPSR1-B. Our findings suggest an isoform-specific link to pathogenetic processes in asthma and allergy.Neuropeptide S receptor 1 (NPSR1 also GPRA, GPR154) was first identified as an asthma susceptibility gene through positional cloning [1]. The genetic evidence was supported by significant single nucleotide polymorphism (SNP) and haplotype associations to asthma in three separate populations. To date, the association of NPSR1 to asthma and allergy has been replicated in seven independent populations [2-8]. Studies have also reported involvement of NPSR1 in inflammatory disorders of skin and intestine [9,10], neurally related traits such as sleep and circadian phenotypes [11] and anxiety [12].NPSR1 is a 7-transmembrane G-protein coupled receptor (GPCR) phylogenetically related to other neuropeptide receptors such as neuropeptide Y (NPY), neurotensin and tachykinin receptors [13]. Upon stimulation by neuropeptide S (NPS), the natural ligand for NPSR1, downstream signalling has been shown to be mediated through intracellular coupling to Gαq and Gαs [14,15]. Several NPSR1 splice variants have been identified but only two, NPSR1-A and NPSR1-B are effectively transported to the plasma
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