bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stochastic Transport of Magnetic Field Lines in the Symmetric Tokamap
Authors: Wingen A. , Spatschek K. H. , Abdullaev S. 
Published: September 2005

AbstractThe topological structure and the statistical properties of stochastic magnetic fields are investigated on the basis of the so called tokamap. First, a monotonic safety factor (q‐profile) is assumed. As it is demonstrated, the transition from the continuous model to the discrete mapping in its symmetric form is essential, not only for the symplectic structure, but also for the precise values characterizing the transition to chaos (e.g. the break‐up of the KAM surfaces) in applications. Statistical properties of the symmetric tokamap, such as escape rates and anomalous diffusion properties, are being presented. By a systematic procedure the stable and unstable manifolds of the periodic hyperbolic fixed points and the resulting homoclinic tangles (stochastic layers) are determined. The latter are important for the magnetic field line transport. For a non‐monotonic q‐profile, the differences between the symmetric and non‐symmetric revtokamap become also significant. The symmetric revtokamap represents an open nonlinear dynamical system which is characterized here with the relevant tools. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
PECVD of Carbon Nanostructures in Hydrocarbon‐Based RF Plasmas
Authors: Ostrikov K. , Tsakadze Z. , Rutkevych P. P. , Long J. D. , Xu S. , Denysenko I. 
Published: September 2005

AbstractDifferent aspects of the plasma‐enhanced chemical vapor deposition of various carbon nanostructures in the ionized gas phase of high‐density, low‐temperature reactive plasmas of Ar+H2+CH4 gas mixtures are studied. The growth techniques, surface morphologies, densities and fluxes of major reactive species in the discharge, and effects of the transport of the plasma‐grown nanoparticles through the near‐substrate plasma sheath are examined. Possible growth precursors of the carbon nanostructures are also discussed. In particular, the experimental and numerical results indicate that it is likely that the aligned carbon nanotip structures are predominantly grown by the molecular and radical units, whereas the plasma‐grown nanoparticles are crucial components of polymorphous carbon films. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Magnetic Field Effect on the Volt‐Equivalent of Arc Spot Heat Flux
Authors: Essiptchouk A. M. , Marotta A. , Sharakhovsky L. I. 
Published: September 2005

AbstractThe results of an experimental study of the arc spot heat flux on the copper cathode of a coaxial Electric Arc Heaters (EAH), with magnetically driven arc, in air are presented. The three rings method was used for indirect separation of arc spot heat flux from total heat entering the electrode. As a result of joint generalizing new and previously published data, the linear dependence of the volt equivalent of arc spot heat flux on magnetic field was obtained for the range B = 0.01 – 1 Tesla and atmospheric pressure. A method, which allows to improve the measurement of the volt equivalent in highly unsteady arc spots, is proposed. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Distinct patterns of MCM protein binding in nuclei of S phase and rereplicating SV40‐infected monkey kidney cells
Authors: Friedrich Thomas D. , Bedner Elzbieta , Darzynkiewicz Zbigniew , Lehman John M. 
Published: September 2005

AbstractBackgroundSimian Virus 40 (SV40) infection of growth‐arrested monkey kidney cells stimulates S phase entry and the continued synthesis of both viral and cellular DNA. Infected cells can attain total DNA contents as high as DNA Index, DI = 5.0–6.0 (10–12C), with host cell DNA representing 70–80% of the total. In this study, SV40‐infected and uninfected control cells were compared to determine whether continued DNA replication beyond DI = 2.0 was associated with rebinding of the minichromosome maintenance (MCM) hexamer, the putative replicative helicase, to chromatin.MethodLaser scanning cytometry was used to measure the total expression per cell and the chromatin/matrix‐association of two MCM subunits in relation to DNA content.ResultsMCM2 and MCM3 proteins that were associated with the chromatin/matrix fraction in G1 phase of both uninfected and SV40‐infected cells were gradually released during progression through S phase. However, in SV40‐infected cells that progressed beyond DI = 2.0, chromatin/matrix‐associated MCM2 and MCM3 remained at the low levels observed at the end of S phase. Rereplication was not preceded by an obvious rebinding of MCM proteins to chromatin, as was observed in G1 phase.ConclusionsThe rereplication of host cell DNA in the absence of the reassociation of MCM proteins with chromatin indicates that SV40 infection induces a novel mechanism of licensing cellular DNA replication. © 2005 International Society for Analytical Cytology
Characterization of cells with different mitochondrial membrane potential during apoptosis
Authors: Lugli Enrico , Troiano Leonarda , Ferraresi Roberta , Roat Erika , Prada Nicole , Nasi Milena , Pinti Marcello , Cooper Edwin L. , Cossarizza Andrea 
Published: September 2005

AbstractBackgroundUntil now, the simultaneous analysis of several parameters during apoptosis, including DNA content and mitochondrial membrane potential (ΔΨ), has not been possible because of the spectral characteristics of the commonly used dyes. Using polychromatic flow cytometry based upon multiple laser and UV lamp excitation, we have characterized cells with different ΔΨ during apoptosis.MethodsU937 cells were treated with the flavonoid quercetin (Qu) and stained with JC‐1 to detect ΔΨ, propidium iodide (PI) for cell viability, Hoechst 33342 for DNA content, Annexin V conjugated with Alexa Fluor‐647 for detection of phosphatidilserine (PS) exposure, marker of early apoptosis, or Mitotracker Deep Red for the determination of mitochondrial mass.ResultsTreatment with Qu provoked the onset of three cell populations with different ΔΨ: (1) healthy cells, with normal ΔΨ, DNA content and physical parameters, high mitochondrial mass, PI‐ and Annexin V‐negative; (2) cells with intermediate ΔΨ and normal DNA content, but with physical parameters typical of apoptotic cells and low mitochondrial mass; most of them were PI+ and Annexin V+; (3) cells with collapsed ΔΨ that had low mitochondrial mass and were Annexin‐V+, PI+; half of them showed diminished DNA content. Similar results, i.e. the presence of cells with intermediate ΔΨ, were observed in other models of apoptosis.ConclusionsDuring Qu‐induced apoptosis, loss of ΔΨ, PS exposure, and decrease of mitochondrial mass are early events that precede permeability to PI and loss of DNA. Populations of cells with different ΔΨ, as revealed by flow cytometry after JC‐1 staining, differed also for other parameters associated to apoptosis. Thus, the simultaneous analysis of several parameters by polychromatic flow cytometry permits a better identification of many stages of cell death, and, more in general, allows to evaluate the eventual heterogenic sensibility of the population under study to a given compound. © 2005 Wiley‐Liss, Inc.
A simplified flow cytometry method of CD4 and CD8 cell counting based on thermoresistant reagents: Implications for large scale monitoring of HIV‐infected patients in resource‐limited settings
Authors: Barbesti Silva , Soldini Laura , Carcelain Guisline , Guignet Angelique , Colizzi Vittorio , Mantelli Barbara , Corvaglia Alessandro , Tran‐Minh Thun , Dorigatti Fernanda , Autran Brigitte , Lazzarin Adriano , Beretta Alberto 
Published: September 2005

AbstractObjective:To validate a simplified flow cytometry assay for CD4 and CD8 T cell counting based on monoclonal antibodies which are made resistant to high temperatures (simplified thermoresistant assay (STRA)).Method:The STRA employs FITC‐conjugated anti‐CD4 and anti‐CD8 monoclonal antibodies, predispensed into test tubes and chemically treated to be resistant to high temperatures. Five correlation studies were performed in three different laboratories on a total of 560 blood samples from HIV‐1 infected patients. Each study correlated the STRA with either double or single platform assays currently available. Accelerated stability tests on the FITC‐conjugated monoclonal antibodies were performed to assess the resistance of the STRA to high temperatures.Results:Comparison of STRA with both single platform and double platform assays gave correlation coefficients ranging 0.957–0.987 for CD4+ T cells and 0.946–0.968 for CD8+ T cells. In all correlation studies there was a perfect data overlapping in the low‐pathological interval of CD4+ T cells (0–400 cells/ml). The FITC‐conjugated CD4 and CD8 monoclonal antibodies maintained intact binding activity and fluorescence brightness after storage for 4 weeks at 45°C and can be stored for up to 8 years in regular conditions (+4°C).Conclusions:The STRA correlates well with both single‐platform and double‐platform flow‐cytometry assays currently used to assess CD4+ T cells. The test procedure is simple, rapid, and easy to perform. The reagents can be stored under unfavorable environmental conditions for long period of time. These features should facilitate access to flow cytometry testing in resource‐poor settings. © 2005 Wiley‐Liss, Inc.
Detection of Anisakis simplex‐induced basophil activation by flow cytometry
Authors: Gonzalez‐Muñoz Miguel , Luque Rosario , Nauwelaers Frans , Moneo Ignacio 
Published: September 2005

AbstractBackground:Laboratory diagnosis of anisakidosis is based on specific serum IgE detection. Recently, detection of allergen‐induced basophil activation by flow cytometry has been proposed as a valuable tool for allergy diagnosis.Objective:To evaluate if detection of Anisakis‐induced basophil activation by flow cytometry is a useful tool in the diagnosis of Anisakis allergy.Methods:Patients with Anisakis allergy (A.s.+, n = 37), patients reporting chronic urticaria or abdominal pain unrelated to fish ingestion (A.s.−, n = 51), and healthy controls (n = 12) were studied. Specific IgE to Anisakis simplex (A. simplex) was quantified with CAP‐FEIA method, and basophil activation test was performed with three different concentrations of an Anisakis crude extract. Basophil gating was performed with CD123 and HLA‐DR, and cellular activation was measured with CD63.Results:A.s.+ patients showed significantly higher age and total IgE levels than did the A.s.− patients. Specific IgE to A. simplex correlated with the activated basophil percentages obtained with 15 μg/mL (r = 0.80; P < 0.001), 1.5 μg/mL (r = 0.84; P < 0.001), and 0.15 μg/mL (r = 0.82; P < 0.001) of A. simplex crude extract. Nine individuals (3 in the A.s.+ group and 6 in the A.s.− group) were nonresponders to basophil stimulation with anti‐IgE. Five A.s.− patients showed positive IgE values to A. simplex while the basophil activation test was negative.According to the receiver operating characteristics curves performed between A.s.+ vs. A.s.− and A.s.+ vs. healthy controls, the cutoff for a positive basophil activation test was ≥21% (specificity = 96%, sensitivity = 100%), and 16% (sensitivity and specificity of 100%) respectively. When nonresponders were included in the A.s.+ vs. A.s.− analysis, sensitivity decreased to 95%. Multivariate logistic analysis showed that the specific basophil activation was a factor independently associated with clinical symptoms of A. simplex allergy.Conclusions:Detection of A. simplex‐induced basophil activation by flow cytometry is a useful laboratory technique for the diagnosis of anisakidosis, supplementing specific IgE determinations. © 2005 Wiley‐Liss, Inc.
Comparison of diagnostic and relapse flow cytometry phenotypes in childhood acute lymphoblastic leukemia: Implications for residual disease detection: A report from the children's oncology group
Authors: Borowitz Michael J , Pullen D Jeanette , Winick Naomi , Martin Paul L , Bowman W Paul , Camitta Bruce 
Published: September 2005

AbstractBackground:Flow cytometric analysis of minimal residual disease (MRD) depends on detecting phenotypically abnormal populations. However, little is known about how phenotypic shifts between diagnosis and relapse affect MRD detection in childhood acute lymphoid leukemia (ALL).Methods:We compared diagnostic and relapse bone marrow specimens in 42 children with precursor B‐ALL studied with the two‐tube panel CD19‐APC/CD45‐PerCP/CD10‐PE/CD20‐FITC and CD19‐APC/CD45‐PerCP/CD9‐PE/CD34‐FITC.Results:At least 29 cases had phenotypic shifts of intensity or coefficient of variation of distribution of one or more markers. Shifts were complex and could not be explained by change in maturation stage. In the majority of cases MRD populations more closely resembled the diagnostic than the relapse specimen. In 6 of 7 MRD negative cases we did not identify an abnormal population that resembled diagnosis or relapse. In the remaining case, in which CD34 and CD10 were lost between diagnosis and relapse, it is possible that we could have missed an MRD population resembling relapse.Conclusions:Phenotypic shifts are common, but do not affect MRD recognition. At most 1 of 42 cases might have harbored an abnormal population undetected because of shift. However, MRD analysis with rigid gating (looking strictly for abnormal phenotypes at diagnosis) might have missed many positive cases, 8 of 22 (36%) in this series. © 2005 Wiley‐Liss, Inc.
Decision criteria for resolving isotype switching conflicts by B cells
Authors: Deenick Elissa K. , Hasbold Jhagvaral , Hodgkin Philip D. 
Published: September 2005

AbstractIsotype switching by B cells is highly regulated by a group of cytokines including IL‐4, IFN‐γ and TGF‐β. A B cell can only express one isotype at a time; however, during an immune response it may be exposed to combinations of stimuli that provide it with conflicting switching instructions. To determine how such cytokine‐induced isotype switch conflicts would be resolved, the responses of B cells exposed to multiple cytokines were investigated. To eliminate complications arising from simultaneous effects of switching cytokines on proliferation, division number was used as a reference framework to monitor switching rate. The results show a clear hierarchy in which IFN‐γ is dominant over IL‐4, and both IL‐4 and IFN‐γ are dominant over TGF‐β. These studies reveal how B cells possess a set of logical decision criteria for dealing with pathogens that invoke a range of different stimuli.
TGF‐β1 production by CD4+CD25+ regulatory T cells is not essential for suppression of intestinal inflammation
Authors: Kullberg Marika C. , Hay Valerie , Cheever Allen W. , Mamura Mizuko , Sher Alan , Letterio John J. , Shevach Ethan M. , Piccirillo Ciriaco A. 
Published: September 2005

AbstractNaturally occurring CD4+CD25+ regulatory T cells (Treg) are potent suppressors of CD4+ and CD8+ T cell responses in vitro and inhibit several organ‐specific autoimmune diseases. While most in vitro studies suggest that CD4+CD25+ Treg cells adopt a cytokine‐independent but cell contact‐dependent mode of T cell regulation, their precise mechanism of suppression in vivo remains largely unknown. Here we examine the functional contribution of Treg cell‐derived TGF‐β1 and effector T cell responsiveness to TGF‐β in CD4+CD25+ T cell‐mediated suppression of inflammatory bowel disease (IBD). We show that CD4+CD25+ Treg cells from either TGF‐β1+/+ or neonatal TGF‐β1–/– mice can suppress the incidence and severity of IBD as well as colonic IFN‐γ mRNA expression induced by WT CD4+CD25– effector T cells. Furthermore, TGF‐β‐resistant Smad3–/– CD4+CD25+ Treg cells are equivalent to WT Treg cells in their capacity to suppress disease induced by either WT or Smad3–/– CD4+CD25– effector T cells. Finally, anti‐TGF‐β treatment exacerbates the colitogenic potential of CD4+CD25– effector T cells in the absence of CD4+CD25+ Treg cells. Together, these data demonstrate that in certain situations CD4+CD25+ T cells are able to suppress intestinal inflammation by a mechanism not requiring Treg cell‐derived TGF‐β1 or effector T cell/Treg cell responsiveness to TGF‐β via Smad3.
A crucial role for macrophages in the pathology of K/B × N serum‐induced arthritis
Authors: Solomon Samuel , Rajasekaran Narendiran , Jeisy‐Walder Elvira , Snapper Scott B. , Illges Harald 
Published: September 2005

AbstractAutoantibodies in the form of immune complexes are known to be crucial mediators in initiating inflammation in a variety of autoimmune diseases. This has been well documented in the anti‐collagen II antibody‐induced arthritis animal model for a long time now. Recently, in the K/B × N mouse model (the F1 of the TCR‐transgenic KRN and the diabetic NOD mice), anti‐glucose‐6‐phosphate isomerase (GPI) autoantibodies have been shown to induce arthritis. Experimental work in the K/B × N model demonstrated key roles of autoantigenic immune complexes activating the alternative pathway of complement, the subsequent association with C5aR and FcγRIII‐mediated cell activation and production of the inflammatory cytokines IL‐1 and TNF‐α, finally leading to joint destruction. The presence of high amounts of inflammatory cytokines and matrix‐degrading proteases at sites of inflammation obviously put the cytokine‐producing macrophages as the next target for investigation in this model. Here, we show that mice depleted of macrophages by clodronate liposome treatment are completely resistant to K/B × N serum‐induced arthritis. Reconstituting clodronate liposome‐treated mice with macrophages from naive animals could reverse this resistance. Also, we found that deficiencies in the Wiskott‐Aldrich syndrome protein and CD40, which are both implicated in macrophage activation, chemotaxis and phagocytosis, are not essential in serum‐induced arthritis. Mast cell degranulation was seen in arthritogenic serum‐treated mice even in the absence of macrophages, possibly suggesting that mast cell degranulation/activation acts hierarchically before macrophages in the inflammatory cascade of anti‐GPI antibody‐induced arthritis.
Role of mast cells in experimental anti‐glomerular basement membrane glomerulonephritis
Authors: Hochegger Kathrin , Siebenhaar Frank , Vielhauer Volker , Heininger Dorothea , Mayadas Tanya N. , Mayer Gert , Maurer Marcus , Rosenkranz Alexander R. 
Published: September 2005

AbstractRecently, divergent reports on the role of mast cells (MC) in different glomerular diseases have brought our attention to their role in an accelerated model of anti‐glomerular basement membrane (GBM) glomerulonephritis (GN). Genetically MC‐deficient KitW/KitW‐v mice, MC‐reconstituted KitW/KitW‐v mice and Kit+/+ control mice were subjected to anti‐GBM GN. Kit+/+ mice developed moderate proteinuria and glomerular damage following the induction of anti‐GBM nephritis. In contrast, proteinuria and glomerular damage were dramatically increased in MC‐deficient KitW/KitW‐v mice. MC‐reconstituted KitW/KitW‐v mice showed proteinuria and glomerular damage comparable to Kit+/+ mice. A significant increase in infiltrating T cells and macrophages was detected in MC‐deficient KitW/KitW‐v mice as compared to Kit+/+ control mice and MC‐reconstituted KitW/KitW‐v mice. Accordingly, we observed an increase of TGF‐β1 mRNA in kidneys from KitW/KitW‐v mice. Interestingly, we did not detect MC in the kidney using either Giemsa staining or RT‐real‐time PCR, but MC were found in the regional lymph nodes. Finally, mortality of KitW/KitW‐v mice was significantly increased after the induction of anti‐GBM GN due to uremia. Our report provides the first direct evidence that MC are protective in anti‐GBM GN, possibly by modulating the influx of effector T cells and macrophages to inflammatory sites in the kidney.
The ratio between dendritic cells and T cells determines the outcome of their encounter: Proliferation versus deletion
Authors: Höpken Uta E. , Lehmann Insa , Droese Jana , Lipp Martin , Schüler Thomas , Rehm Armin 
Published: September 2005

AbstractDendritic cells (DC) either induce T cell tolerance or contribute to the initiation and modulation of T and B cell responses. Since many of the variables determining the thresholds of naive T cell priming were defined in vitro using a homogeneously matured DC population, we here focused on partially mature DC which might reflect the occurrence of tumor‐infiltrating and thymic DC. To predict how those DC regulate the induction of antigen‐specific T cell proliferation and T cell tolerance, we co‐cultured ovalbumin‐pulsed murine DC at different ratios with antigen‐specific DO11.10 transgenic T cells. Whereas partially mature DC at a DC/T cell ratio of 1 : 10 supported proliferation, a DC/T cell ratio of 1 : 2 induced proliferation arrest in naive CD4+ T cells. The acquisition of the NK cell inhibitory markers NK1.1 and KLRG on T cells exposed to high numbers of DC suggests a role for these molecules in the protection of antigen‐responsive T cells from exhaustion by overstimulation. Mechanistically, abortive T cell proliferation upon encounter of high numbers of partially mature DC is caused by an apoptosis‐related pathway, suggesting that excessive antigen density without sufficient costimulation results in activation‐induced cell death.
Human splenic marginal zone B cells lack expression of activation‐induced cytidine deaminase
Authors: Willenbrock Klaus , Jungnickel Berit , Hansmann Martin‐Leo , Küppers Ralf 
Published: September 2005

AbstractIt has been speculated that somatic hypermutation of rearranged immunoglobulin variable (V) region genes does not only take place in the germinal center (GC) microenvironment, but also in the marginal zone (MZ) of the spleen, and that human peripheral blood IgM‐positive B cells with somatically mutated V region genes may derive from mutating MZ B cells. As somatic hypermutation is strictly dependent on the enzyme activation‐induced cytidine deaminase (AID), we used an AID‐specific monoclonal antibody that is suitable for immunohistochemical staining to analyze human splenic MZ cells for AID expression. Analysis of tissue sections from 29 spleens revealed only very rare MZ cells (approx. 0.05%) showing AID staining, whereas in 25 of the spleen samples strong AID staining of GC B cells was observed. Thus, there are virtually no AID‐expressing MZ B cells, indicating that somatic hypermutation does not take place at a significant level in the MZ. Consequently, it appears unlikely that the somatically mutated IgM B cells are generated in the splenic MZ. Moreover, the lack of AID‐positive MZ B cells questions the recent speculation that B cell chronic lymphocytic leukemias with mutated V genes are derived from mutating MZ B cells.See accompanying commentary: http://dx.doi.org/10.1002/eji.200535446
Fluorine in Peptide Design and Protein Engineering
Authors: Jäckel Christian , Koksch Beate 
Published: September 2005

AbstractThe use of fluorine has become well established in the analysis of protein structure and function, e.g. in tools such as 19F NMR spectroscopy. The application of the unique electronic properties of this element for the structural and chemical modification of peptides and proteins emerged as a promising approach. However, the influences of amino acid fluorination on side‐chain interactions in proteins are still controversially discussed. The systematic investigation of the interaction properties of fluoroalkyl groups in a native polypeptide environment broadens the scope of fluorinated amino acids to the rational design of structural motifs and protein interfaces. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)