bluuebunny/crossref_metadata_2025_split huggingface dataset:
Infection with a Helminth Parasite Attenuates Autoimmunity through TGF-β-Mediated Suppression of Th17 and Th1 Responses
Authors: Walsh Kevin P. , Brady Miriam T. , Finlay Conor M. , Boon Louis , Mills Kingston H. G. 
Published: July 2009

Abstract
The lower incidence of allergy and autoimmune diseases in developing countries has been associated with a high prevalence of parasitic infections. Here we provide direct experimental evidence that parasites can exert bystander immunosuppression of pathogenic T cells that mediate autoimmune diseases. Infection of mice with Fasciola hepatica resulted in recruitment of dendritic cells, macrophages, eosinophils, neutrophils, and CD4+ T cells into the peritoneal cavity. The dendritic cells and macrophages in infected mice expressed IL-10 and latency-associated peptide, and they had low surface expression of costimulatory molecules and/or MHC class II. Furthermore, most CD4+ T cells in the peritoneal cavity of infected mice secreted IL-10, but not IFN-γ or IL-4. There was a less significant expansion of CD4+Foxp3+ T cells. F. hepatica-specific Tr1-type clones generated from infected mice suppressed proliferation and IFN-γ production by Th1 cells. Infection was associated with suppression of parasite-specific Th1 and Th2 responses, which was reversed in IL-10-defective mice. Infection with F. hepatica also exerted bystander suppression of immune responses to autoantigens and attenuated the clinical signs of experimental autoimmune encephalomyelitis. Protection was associated with suppression of autoantigen-specific IFN-γ and IL-17 production. The suppression of Th1 and Th17 responses and attenuation of experimental autoimmune encephalomyelitis by F. hepatica was maintained in IL-10−/− mice but was reversed by neutralization of TGF-β in vivo. Our study provides evidence that F. hepatica-induced IL-10 subverts parasite-specific Th1 and Th2 responses, but that F. hepatica-induced TGF-β plays a critical role in bystander suppression of autoantigen-specific Th1 and Th17 responses that mediate autoimmune diseases.
NLRP3 (NALP3, Cryopyrin) Facilitates In Vivo Caspase-1 Activation, Necrosis, and HMGB1 Release via Inflammasome-Dependent and -Independent Pathways
Authors: Willingham Stephen B. , Allen Irving C. , Bergstralh Daniel T. , Brickey Willie June , Huang Max Tze-Han , Taxman Debra J. , Duncan Joseph A. , Ting Jenny P.-Y. 
Published: July 2009

Abstract
Bacterial infection elicits a range of beneficial as well as detrimental host inflammatory responses. Key among these responses are macrophage/monocyte necrosis, release of the proinflammatory factor high-mobility group box 1 protein (HMGB1), and induction of the cytokine IL-1. Although the control of IL-1β has been well studied, processes that control macrophage cell death and HMGB1 release in animals are poorly understood. This study uses Klebsiella pneumonia as a model organism because it elicits all three responses in vivo. The regulation of these responses is studied in the context of the inflammasome components NLRP3 and ASC, which are important for caspase-1 activation and IL-1β release. Using a pulmonary infection model that reflects human infection, we show that K. pneumonia-induced mouse macrophage necrosis, HMGB1, and IL-1β release are dependent on NLRP3 and ASC. K. pneumoniae infection of mice lacking Nlrp3 results in decreased lung inflammation and reduced survival relative to control, indicating the overall protective role of this gene. Macrophage/monocyte necrosis and HMGB1 release are controlled independently of caspase-1, suggesting that the former two responses are separable from inflammasome-associated functions. These results provide critical in vivo validation that the physiologic role of NLRP3 and ASC is not limited to inflammasome formation.
Late Endosome/Lysosome-Localized Rab7b Suppresses TLR9-Initiated Proinflammatory Cytokine and Type I IFN Production in Macrophages
Authors: Yao Ming , Liu Xingguang , Li Dong , Chen Taoyong , Cai Zhen , Cao Xuetao 
Published: July 2009

Abstract
Inappropriate activation of TLR9 has been found to be involved in the pathogenesis of autoimmune diseases such as systemic lupus erythematosus. TLR9 antagonists have been proposed to be therapeutic for some kinds of autoimmune diseases. In contrast, new negative regulators of TLR9 signal pathway need to be identified, and the mechanisms for the control of TLR9 response need to be fully investigated. It is well known that TLR9 will be finally transported to late endosome/lysosome once activated; however, the exact mechanism and the biological significance of the redistribution have not been fully elucidated. Ras related in brain (Rab)7b is a small guanosine triphosphatase, identified by us before, which is mainly localized in late endosome/lysosome. Our previous study shows that Rab7b can negatively regulate TLR4 signaling by promoting lysosomal degradation of TLR4. In this study, we show that TLR9 ligation can inhibit Rab7b expression in macrophages via ERK and p38 activation. In turn, the late endosome/lysosome-localized Rab7b can colocalize with TLR9 in lysosomal-associated membrane protein 1-positive compartment and down-regulate the expression of the TLR9 in macrophages by promoting TLR9 degradation once TLR9 is activated. Accordingly, Rab7b can negatively regulate TLR9-triggered production of TNF-α, IL-6, and IFN-β in macrophages by impairing activation of MAPKs and NF-κB pathways. Our results suggest that the late endosome/lysosome-localized Rab7b can down-regulate TLR9-triggered proinflammatory cytokine and type I IFN production by impairing TLR9 signaling via promotion of TLR9 degradation.
Tissue-Specific Abundance of Regulatory T Cells Correlates with CD8+ T Cell Dysfunction and Chronic Retrovirus Loads
Authors: Myers Lara , Messer Ronald J. , Carmody Aaron B. , Hasenkrug Kim J. 
Published: July 2009

Abstract
Infection of mice with Friend virus induces the activation of CD4+ regulatory T cells (Tregs) that suppress virus-specific CD8+ T cells. This suppression leads to incomplete virus clearance and the establishment of virus persistence. We now show that Treg-mediated suppression of CD8+ T cells is tissue specific, occurring in the spleen but not the liver. Regardless of infection status, there was a 5-fold lower proportion of Tregs in the liver than in the spleen, much lower absolute cell numbers, and the relatively few Tregs present expressed less CD25. Results indicated that reduced expression of CD25 on liver Tregs was due to microenvironmental factors including low levels of IL-2 production by CD4+ Th cells in that tissue. Low CD25 expression on liver Tregs did not impair their ability to suppress CD8+ T cells in vitro. Correlating with the decreased proportion of Tregs in the liver was a significantly increased proportion of virus-specific CD8+ T cells compared with the spleen. The virus-specific CD8+ T cells from the liver did not appear suppressed given that they produced both IFN-γ and granzyme B, and they also showed evidence of recent cytolytic activity (CD107a+). The functional phenotype of the virus-specific CD8+ T cells correlated with a 10-fold reduction of chronic Friend virus levels in the liver compared with the spleen. Thus, suppression of CD8+ T cells by virus-induced Tregs occurs in a tissue-specific manner and correlates with profound effects on localized levels of chronic infection.
A Critical Role for REV1 in Regulating the Induction of C:G Transitions and A:T Mutations during Ig Gene Hypermutation
Authors: Masuda Keiji , Ouchida Rika , Li Yingqian , Gao Xiang , Mori Hiromi , Wang Ji-Yang 
Published: July 2009

Abstract
REV1 is a deoxycytidyl transferase that catalyzes the incorporation of deoxycytidines opposite deoxyguanines and abasic sites. To explore the role of its catalytic activity in Ig gene hypermutation in mammalian cells, we have generated mice expressing a catalytically inactive REV1 (REV1AA). REV1AA mice developed normally and were fertile on a pure C57BL/6 genetic background. B and T cell development and maturation were not affected, and REV1AA B cells underwent normal activation and class switch recombination. Analysis of Ig gene hypermutation in REV1AA mice revealed a great decrease of C to G and G to C transversions, consistent with the disruption of its deoxycytidyl transferase activity. Intriguingly, REV1AA mice also exhibited a significant reduction of C to T and G to A transitions. Moreover, each type of nucleotide substitutions at A:T base pairs was uniformly reduced in REV1AA mice, a phenotype similar to that observed in mice haploinsufficient for Polh. These results reveal an unexpected role for REV1 in the generation of C:G transitions and A:T mutations and suggest that REV1 is involved in multiple mutagenic pathways through functional interaction with other polymerases during the hypermutation process.
The CCL7-CCL2-CCR2 Axis Regulates IL-4 Production in Lungs and Fungal Immunity
Authors: Szymczak Wendy A. , Deepe George S. 
Published: July 2009

Abstract
Expression of the chemokine receptor CCR2 can be detrimental or beneficial for infection resolution. Herein, we examined whether CCR2 was requisite for control of infection by the dimorphic fungus Histoplasma capsulatum. H. capsulatum-infected CCR2−/− mice manifested defects in inflammatory cell recruitment, increased IL-4, and progressive infection. Increased IL-4 in CCR2−/− mice primarily contributed to decreased host resistance as demonstrated by the ability of IL-4-neutralized CCR2−/− mice to resolve infection without altering inflammatory cell recruitment. Surprisingly, numerous alveolar macrophages and dendritic cells contributed to IL-4 production in CCR2−/− mice. IL-4-mediated impairment of immunity in CCR2−/− mice was associated with increased arginase-1 and YM1 transcription and increased transferrin receptor expression by phagocytic cells. Immunity in mice lacking the CCR2 ligand CCL2 was not impaired despite decreased inflammatory cell recruitment. Neutralization of the CCR2 ligand CCL7 in CCL2−/− mice, but not wild type, resulted in increased IL-4 and fungal burden. Thus, CCL7 in combination with CCL2 limits IL-4 generation and exerts control of host resistance. Furthermore, increased phagocyte-derived IL-4 in CCR2−/− mice is associated with the presence of alternatively activated phagocytic cells.
Unprecedent Chemo‐ and Stereoselective Palladium‐Catalysed Methoxycarbonylation of Norbornene
Authors: Blanco Carolina , Ruiz Aurora , Godard Cyril , Fleury‐Brégeot Nicolas , Marinetti Angela , Claver Carmen 
Published: July 2009

AbstractCatalytic systems able to control chemo‐ and stereoselectivity have been tested in the palladium‐catalysed methoxycarbonylation of norbornene. An enantioselectivity of up to 40% was obtained.
Lanthanide Bis[(trifluoromethyl)sulfonyl]imides as Reusable Catalysts for Mononitration of Substituted Benzenes in Ionic Liquids
Authors: Wang Shuojin , Jiang Shaojie , Nie Jin 
Published: July 2009

AbstractLanthanide bis[(trifluoromethyl)sulfonyl]imides as a kind of effective catalyst were used in quaternary ammonium ionic liquids to afford a useful new method for the nitration of substituted benzenes with concentrated nitric acid (95%) as nitrating agent. The less expensive lanthanum bis[(trifluoromethyl)sulfonyl]imide was found to be the most effective catalyst employed in the ionic liquid tributylammonium bis[(trifluoromethyl)sulfonyl]imide. The lanthanum bis[(trifluoromethyl)sulfonyl]imide/tributylammonium bis[(trifluoromethyl)sulfonyl]imide system demonstrated high catalytic activity for the nitration of halobenzenes and rendered good to excellent yields. This catalyst/ionic liquid system could be recovered by simple procedures and recycled for at least 5 times.
Reactivation of spent Pd/AC catalyst by supercritical CO2fluid extraction
Authors: Zhang Xiaoxin , Zong Baoning , Qiao Minghua 
Published: July 2009

AbstractIn this article, we reported a nondestructive and environmentally friendly method for the reactivation of a spent Pd/AC catalyst for the hydrogenation of benzoic acid by using supercritical CO2(scCO2) fluid extraction. The effects of reactivation conditions, such as extraction temperature, pressure, CO2flow rate, and time, on the activity of the reactivated Pd/AC catalyst, were presented. The catalyst was characterized by N2physisorption, laser particle size analysis, and transmission electron spectroscopy, and the liquid extract was analyzed by GC‐MS. It is found that scCO2fluid extraction was very efficient in eliminating organic substances blocking the pores of the catalyst, while did not affect noticeably the granule size of the catalyst and the particle size of Pd. The reactivated Pd/AC catalyst regained more than 70% of the activity of the fresh 5.0 wt % Pd/AC catalyst, and has been successfully used in an industrial unit for the hydrogenation of benzoic acid. © 2009 American Institute of Chemical Engineers AIChE J, 2009
Multimodal microglia imaging of fiber tracts in acute subcortical stroke
Authors: Radlinska Basia A. , Ghinani Sasan A. , Lyon Paul , Jolly Dean , Soucy Jean‐Paul , Minuk Jeffrey , Schirrmacher Ralf , Thiel Alexander 
Published: July 2009

AbstractObjectiveCase series with11C‐PK11195 and positron emission tomography (PET) in stroke patients suggest that activated microglia may be detected in remote brain regions with fiber tract connections to the lesion site as an indicator of poststroke neuroinflammation. However, the specificity of these imaging findings remains to be demonstrated.MethodsIn a prospective controlled study, we measured microglia activity using11C‐PK11195‐PET along the pyramidal tract, as defined by diffusion tensor imaging, in 21 patients with first‐time acute subcortical ischemia within 2 weeks of stroke. Uptake ratios (affected vs unaffected side) were determined for a set of standardized volumes of interest along the pyramidal tracts (PT). Uptake ratios from patients in whom the PT was affected were compared with those in whom the PT was not affected. Uptake ratios were related to motor deficit and lesion size according to correlation analyses.ResultsIncreased uptake ratios were only found in patients in whom the PT was affected by stroke. In the affected hemisphere, uptake was increased at the level of pons, midbrain, and internal capsule, but not in the oval center. The extent of remote microglia activation was independent of infarct size or clinical measures of stroke severity.InterpretationA specific activation of microglia was only found in patients in whom the PT was affected by the stroke and only caudal (anterograde) to the lesion; no activation was found in the retrograde direction or in those patients in whom the PT was not affected. These findings were independent of infarct size and may represent changes secondary to early Wallerian degeneration. Ann Neurol 2009;66:825–832
Acute hyperglycemia produces transient improvement in glucose transporter type 1 deficiency
Authors: Akman Cigdem I. , Engelstad Kristin , Hinton Veronica J. , Ullner Paivi , Koenigsberger Dorcas , Leary Linda , Wang Dong , De Vivo Darryl C. 
Published: July 2009

AbstractObjectiveGlucose transporter type 1 deficiency syndrome (Glut1‐DS) is characterized clinically by acquired microcephaly, infantile‐onset seizures, psychomotor retardation, choreoathetosis, dystonia, and ataxia. The laboratory signature is hypoglycorrhachia. The 5‐hour oral glucose tolerance test (OGTT) was performed to assess cerebral function and systemic carbohydrate homeostasis during acute hyperglycemia, in the knowledge that GLUT1 is constitutively expressed ubiquitously and upregulated in the brain.MethodsThirteen Glut1‐DS patients completed a 5‐hour OGTT. Six patients had prolonged electroencephalographic (EEG)/video monitoring, 10 patients had plasma glucose and serum insulin measurements, and 5 patients had repeated measures of attention, memory, fine motor coordination, and well‐being. All patients had a full neuropsychological battery prior to OGTT.ResultsThe glycemic profile and insulin response during the OGTT were normal. Following the glucose load, transient improvement of clinical seizures and EEG findings were observed, with the most significant improvement beginning within the first 30 minutes and continuing for 180 minutes. Thereafter, clinical seizures returned, and EEG findings worsened. Additionally, transient improvement in attention, fine motor coordination, and reported well‐being were observed without any change in memory performance.InterpretationThis study documents transient neurological improvement in Glut1‐DS patients following acute hyperglycemia, associated with improved fine motor coordination and attention. Also, systemic carbohydrate homeostasis was normal, despite GLUT1 haploinsufficiency, confirming the specific role of GLUT1 as the transporter of metabolic fuel across the blood‐brain barrier. The transient improvement in brain function underscores the rate‐limiting role of glucose transport and the critical minute‐to‐minute dependence of cerebral function on fuel availability for energy metabolism. ANN NEUROL 2010;67:31–40
Dynamic cure kinetics of epoxy–novolac compounds as studied by differential scanning calorimetry
Authors: Yang Shin‐Shiao , Hsieh Tar‐Hwa , Bi Hsiaotao T , Ho Ko‐Shan , Ho Tsung‐Han , Chen Ho‐Ruei , Ye Shi‐Hao , Chang Yu‐Chen 
Published: July 2009

AbstractThe cure kinetics of epoxy–novolac compounds were studied by means of differential scanning calorimetry with a dynamic approach. On the basis of a modified version of our previously reported kinetic model, a procedure aiming at the phenomenological description of the cure kinetics was developed. The reactions were found to be autocatalytic in nature for both commercial epoxy–novolac molding compounds and silica‐free imidazole‐cured epoxy–novolac systems. The weak extent of autocatalysis in the epoxy–novolac molding compounds was likely due to their high content of silica fillers. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Synthesis of guar‐gum‐stabilized nanosized silver clusters with γ radiation
Authors: Biswal Jayashree , Ramnani S. P. , Shirolikar Seema , Sabharwal S. 
Published: July 2009

AbstractGamma ray induced synthesis of Ag clusters in the aqueous medium has been carried out using natural polysaccharide guar gum as a stabilizer. The results showed that guar gum is very effective in binding the Ag clusters and restricts their size in the nano region. The surface plasmon resonance band in the wavelength range of 410–425 nm of visible region has confirmed the formation of Ag clusters. The size of the clusters is governed by the concentration of both, i.e. precursor Ag+ and guar gum. The clusters were characterized by TEM and XRD, which shows that the size of clusters is in the range of 10–30 nm. The results have shown that silver clusters stabilized by guar gum are stable in acid media and alkaline media is not a desired media for the synthesis. From thermogravimetric analysis it has been demonstrated that incorporation of nano sized Ag clusters within guar gum improves the thermal properties of irradiated guar gum. To the best of our knowledge, the use of guar gum as a stabilizer in the gamma ray induced synthesis of Ag nano clusters is being reported first time in the literature. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Physical properties of water‐blown rigid polyurethane foams containing epoxidized soybean oil in different isocyanate indices
Authors: Tu Yuan‐Chan , Fan Hongyu , Suppes Galen J. , Hsieh Fu‐Hung 
Published: July 2009

AbstractTo explore the potential of isocyanate usage reduction, water‐blown rigid polyurethane foams were made by replacing 0, 20, and 50% of Voranoll® 490 in the B‐side of the foam formulation by epoxidized soybean oil (ESBO) with an isocyanate index ranging from 50 to 110. The compressive strength, density, and thermal conductivity of foams were measured. The foam surface temperature was monitored before and throughout the foaming reaction as an indirect indication of the foaming temperature. Increasing ESBO replacement and/or decreasing isocyanate index decreased the foam's compressive strength. The density of the foam decreased while decreasing the isocyanate index to 60. Further decrease in isocyanate index resulted in foam shrinkage causing a sharp increase in the foam density. The thermal conductivity of foams increased while decreasing the isocyanate index and increasing the ESBO replacement. Mathematical models for predicting rigid polyurethane foam density, compressive strength, and thermal conductivity were established and validated. Similar to compressive strength, the foaming temperature decreased while decreasing the isocyanate index and increasing the ESBO replacement. Because of the lower reactivity of ESBO with isocyanate, the rate of foaming temperature decrease with decreasing isocyanate index was in the order of 0% > 20% > 50% ESBO replacement. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Damping behavior of wood filled polypropylene composites
Authors: Chauhan Shakti , Karmarkar Ajay , Aggarwal Pankaj 
Published: July 2009

AbstractThe damping coefficient (tanδ) of wood flour filled polypropylene composites, having varying filler concentrations were measured using the free vibration decay of disk‐shaped specimen, vibrating in flexural vibration mode. The damping coefficients decreased with the increase of filler load in composites. There was no significant difference in damping behavior of composites with and without compatiblizer at low filler level (upto 30%). At higher filler loading (>30%), composites with compatiblizer had lower damping coefficient suggesting improved interfacial adhesion between wood and polypropylene. The damping in composite is attributed to the damping because of the composite constituents and damping at the interface. The damping because of interface was estimated using a model and was found to increase with the increase in filler loading. At higher filler content, damping due to interface in composites with compatiblizer was significantly lower than in composites without compatiblizer suggesting a better interfacial adhesion between the wood filler and polypropylene matrix with compatiblizer. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Infrared light‐active shape memory polymer filled with nanocarbon particles
Authors: Leng Jinsong , Wu Xuelian , Liu Yanju 
Published: July 2009

AbstractIn addition to the fabrication of thermoset styrene‐based shape memory polymer (SMP) and its nanocomposite filled with nanocarbon particles, this study presents the effect of nanocarbon particles on infrared light‐active shape recovery behaviors of this type of SMP material. The experimental results reveal that both pure SMP and SMP filled with nanocarbon particles can be actuated by infrared light in vacuum, while shape memory effect shown by the composite is stronger than that of in pure SMP. Shape memory effect is evaluated by shape recovery ability and shape recovery speed in detail. Moreover, factors which would influence the infrared light‐active shape memory effect in SMP with/without nanocarbon particles are explored by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and infrared absorption characteristic tests. The better shape memory effect of the nanocomposite attributes to its higher storage modulus and higher infrared absorption capability. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009