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Search Results: 1 - 10 of 408630 matches for " Steven M Varga "
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Depletion of Alveolar Macrophages Ameliorates Virus-Induced Disease following a Pulmonary Coronavirus Infection
Stacey M. Hartwig, Kaitlyn M. Holman, Steven M. Varga
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0090720
Abstract: Coronaviruses cause respiratory disease in humans that can range from mild to severe. However, the pathogenesis of pulmonary coronavirus infections is poorly understood. Mouse hepatitis virus type 1 (MHV-1) is a group 2 coronavirus capable of causing severe morbidity and mortality in highly susceptible C3H/HeJ mice. We have previously shown that both CD4 and CD8 T cells play a critical role in mediating MHV-1-induced disease. Here we evaluated the role of alveolar macrophages (AM) in modulating the adaptive immune response and subsequent disease. Depletion of AM using clodronate liposomes administered prior to MHV-1 infection was associated with a significant amelioration of MHV-1-induced morbidity and mortality. AM depletion resulted in a decreased number of virus-specific CD4 T cells in the lung airways. In addition, a significant increase in the frequency and total number of Tregs in the lung tissue and lung airways was observed following MHV-1 infection in mice depleted of AM. Our results indicate that AM play a critical role in modulating MHV-1-induced morbidity and mortality.
The Initial Draining Lymph Node Primes the Bulk of the CD8 T Cell Response and Influences Memory T Cell Trafficking after a Systemic Viral Infection
Matthew R. Olson equal contributor,Daniel S. McDermott equal contributor,Steven M. Varga
PLOS Pathogens , 2012, DOI: 10.1371/journal.ppat.1003054
Abstract: Lymphocytic choriomeningitis virus (LCMV) causes a systemic infection in mice with virus replication occurring in both peripheral tissues and secondary lymphoid organs. Because of the rapid systemic dissemination of the virus, the secondary lymphoid organs responsible for the induction of the LCMV-specific CD8 T cell response are poorly defined. We show that the mediastinal lymph node (MedLN) serves as the primary draining lymph node following LCMV infection. In addition, we demonstrate that the MedLN is responsible for priming the majority of the virus-specific CD8 T cell response. Following resolution of the acute infection, the draining MedLN exhibits characteristics of a reactive lymph node including an increased presence of germinal center B cells and increased cellularity for up to 60 days post-infection. Furthermore, the reactive MedLN harbors an increased frequency of CD62L? effector memory CD8 T cells as compared to the non-draining lymph nodes. The accumulation of LCMV-specific CD62L? memory CD8 T cells in the MedLN is independent of residual antigen and is not a unique feature of the MedLN as footpad infection with LCMV leads to a similar increase of virus-specific CD62L? effector memory CD8 T cells in the draining popliteal lymph node. Our results indicate that CD62L? effector memory CD8 T cells are granted preferential access into the draining lymph nodes for an extended time following resolution of an infection.
Lung tissue bioenergetics and caspase activity in rodents
Ahmed R Alsuwaidi, Mohammed T Alsamri, Ali S Alfazari, Saeeda Almarzooqi, Alia Albawardi, Aws R Othman, Thachillath Pramathan, Stacey M Hartwig, Steven M Varga, Abdul-Kader Souid
BMC Research Notes , 2013, DOI: 10.1186/1756-0500-6-12
Abstract: For Wistar rats, the values of kc and ATP for 0?<?t?≤?7 h (mean?±?SD) were 0.15?±?0.02 μM O2 min-1 mg-1 (n?=?18, coefficient of variation, Cv?=?13%) and 131?±?69 pmol mg-1 (n?=?16, Cv?=?53%), respectively. The AMC peak areas remained relatively small despite a ~5-fold rise over 6 h. Good tissue preservation was evident despite time-dependent increases in apoptotic cells. Lung tissue bioenergetics, caspase activity and structure were deleterious in unoxygenated or intermittently oxygenated solutions. Incubating lung tissue in O2 depleted MEM for 30 min or anesthesia by urethane had no effect on lung bioenergetics, but produced higher caspase activity.Lung tissue bioenergetics and structure could be maintained in vitro in oxygenated buffer for several hours and, thus, used as biomarkers for investigating respiratory pathogens or toxins.In vitro systems for studying tissue mitochondrial O2 consumption (cellular respiration) and morphology in BALB/c mice are recently described [1-3]. These parameters, however, are insufficient for fully assessing cellular viability. For example, cells may respire (consume O2) at a higher rate due to uncoupling oxidative phosphorylation (short-circuiting the inner mitochondrial membrane), an event that results from increased caspase activities [4]. Therefore, measuring cellular ATP and caspase activity are essential biomarkers for a more comprehensive assessment of tissues in vitro.Lung toxicity is a major health concern in the drug development. The US Food and Drug Administration (FDA) has issued several post-marketing drug recalls due to adverse events related to mitochondrial dysfunctions [5]. Thus, developing in vitro systems to assess adverse effects of drugs on lung tissue bioenergetics is important. Drug-induced mitochondrial disturbances have been investigated using different methods, including fluorescence-based oxygen sensitive probes [6-8].In this study, the previously described method [1-3,7] is expanded to include measuremen
Effects of Formalin-Inactivated Respiratory Syncytial Virus (FI-RSV) in the Perinatal Lamb Model of RSV
Rachel J. Derscheid, Jack M. Gallup, Cory J. Knudson, Steven M. Varga, Drew D. Grosz, Albert van Geelen, Shannon J. Hostetter, Mark R. Ackermann
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0081472
Abstract: Respiratory syncytial virus (RSV) is the most frequent cause of bronchiolitis in infants and children worldwide. There are currently no licensed vaccines or effective antivirals. The lack of a vaccine is partly due to increased caution following the aftermath of a failed clinical trial of a formalin-inactivated RSV vaccine (FI-RSV) conducted in the 1960’s that led to enhanced disease, necessitating hospitalization of 80% of vaccine recipients and resulting in two fatalities. Perinatal lamb lungs are similar in size, structure and physiology to those of human infants and are susceptible to human strains of RSV that induce similar lesions as those observed in infected human infants. We sought to determine if perinatal lambs immunized with FI-RSV would develop key features of vaccine-enhanced disease. This was tested in colostrum-deprived lambs immunized at 3–5 days of age with FI-RSV followed two weeks later by RSV infection. The FI-RSV-vaccinated lambs exhibited several key features of RSV vaccine-enhanced disease, including reduced RSV titers in bronchoalveolar lavage fluid and lung, and increased infiltration of peribronchiolar and perivascular lymphocytes compared to lambs either undergoing an acute RSV infection or na?ve controls; all features of RSV vaccine-enhanced disease. These results represent a first step proof-of-principle demonstration that the lamb can develop altered responses to RSV following FI-RSV vaccination. The lamb model may be useful for future mechanistic studies as well as the assessment of RSV vaccines designed for infants.
Benchmark Test Calculation of a Four-Nucleon Bound State
H. Kamada,A. Nogga,W. Gloeckle,E. Hiyama,M. Kamimura,K. Varga,Y. Suzuki,M. Viviani,A. Kievsky,S. Rosati,J. Carlson,Steven C. Pieper,R. B. Wiringa,P. Navratil,B. R. Barrett,N. Barnea,W. Leidemann,G. Orlandini
Physics , 2001, DOI: 10.1103/PhysRevC.64.044001
Abstract: In the past, several efficient methods have been developed to solve the Schroedinger equation for four-nucleon bound states accurately. These are the Faddeev-Yakubovsky, the coupled-rearrangement-channel Gaussian-basis variational, the stochastic variational, the hyperspherical variational, the Green's function Monte Carlo, the no-core shell model and the effective interaction hyperspherical harmonic methods. In this article we compare the energy eigenvalue results and some wave function properties using the realistic AV8' NN interaction. The results of all schemes agree very well showing the high accuracy of our present ability to calculate the four-nucleon bound state.
Problems with classification of spa waters used in balneology  [PDF]
Csaba Varga
Health (Health) , 2010, DOI: 10.4236/health.2010.211187
Abstract: Recently, several measurements have indicated the presence of biologically active organic micropollutants or trace components in different types of waters, including spa and medicinal waters. The wide spectrum and abundance of organic components of spa waters in the Carpathian basin and other European regions has been demonstrated by gas-chromatographic analyses. These components may have main role in the therapeutic and preventive mechanisms. Considering the new analytical data, traditional European classification of spa waters based on the quality and quantity of inorganic ions (salts) should be reevaluated. The association of inorganic components and the therapeutic effects is also necessary to reconsider.
Quantum Monte Carlo calculations of $A=9,10$ nuclei
Steven C. Pieper,K. Varga,R. B. Wiringa
Physics , 2002, DOI: 10.1103/PhysRevC.66.044310
Abstract: We report on quantum Monte Carlo calculations of the ground and low-lying excited states of $A=9,10$ nuclei using realistic Hamiltonians containing the Argonne $v_{18}$ two-nucleon potential alone or with one of several three-nucleon potentials, including Urbana IX and three of the new Illinois models. The calculations begin with correlated many-body wave functions that have an $\alpha$-like core and multiple p-shell nucleons, $LS$-coupled to the appropriate $(J^{\pi};T)$ quantum numbers for the state of interest. After optimization, these variational trial functions are used as input to a Green's function Monte Carlo calculation of the energy, using a constrained path algorithm. We find that the Hamiltonians that include Illinois three-nucleon potentials reproduce ten states in $^9$Li, $^9$Be, $^{10}$Be, and $^{10}$B with an rms deviation as little as 900 keV. In particular, we obtain the correct 3$^+$ ground state for $^{10}$B, whereas the Argonne $v_{18}$ alone or with Urbana IX predicts a 1$^+$ ground state. In addition, we calculate isovector and isotensor energy differences, electromagnetic moments, and one- and two-body density distributions.
Monte Carlo integration in Glauber model analysis of reactions of halo nuclei
Kalman Varga,Steven C. Pieper,Y. Suzuki,R. B. Wiringa
Physics , 2002, DOI: 10.1103/PhysRevC.66.034611
Abstract: Reaction and elastic differential cross sections are calculated for light nuclei in the framework of the Glauber theory. The optical phase-shift function is evaluated by Monte Carlo integration. This enables us to use the most accurate wave functions and calculate the phase-shift functions without approximation. Examples of proton nucleus (e.g. p-$^6$He, p-$^6$Li) and nucleus-nucleus (e.g. $^6$He$-^{12}$C) scatterings illustrate the effectiveness of the method. This approach gives us a possibility of a more stringent analysis of the high-energy reactions of halo nuclei.
On the way toward the sector spanning agrifood process traceability
Mónika Varga,Béla Csukás
Agrárinformatika Folyóirat , 2010,
Abstract: Having overviewed the state-of-art in agrifood traceability, the paper focuses on the multiscale modeling of the underlying problems. The main conclusion is, that there are not really workable sector spanning traceability methods, but the field experts and the computer modeling community seems to be prepared to develop quite new tools in the near future. According to our opinion, the sector encompassing IT centers ought to find a reasonable compromise between the “Schylla” of the simple, step by step passing of traceable unit IDs for the neighboring actors, and the “Carybdis” of accumulating enormously huge databases, containing every relevant data of the actors. The future role of the sector spanning, outside intelligent centers is to provide traceability and trackability service for the actors on cooperative basis of the mutual interests. In addition, the centers have to support the supply chain and value chain management, as well as the work of the authorities, that are responsible for the human health. Present study provides a good basis to our future development of a really sector spanning method. In a following paper we shall outline a sector spanning system on the basis of the Direct Computer Mapping based simulation methodology, in detail.
Application of roof radiant burners in large pusher-type furnaces
A. Varga,M. Tati?,L. Lazi?
Metalurgija , 2009,
Abstract: The paper deals with the application of roof flat-flame burners in the pusher-type steel slab reheating furnaces, after furnace reconstruction and replacement of conventional torch burners, with the objective to increase the efficiency of radiative heat transfer from the refractory roof to the charge. Based on observations and on measurements of the construction and process parameters under operating conditions, the advantages and disadvantages of indirectly oriented radiant heat transfer are analysed in relation to the heat transfer in classically fired furnaces.
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