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Despite the fact that the outstanding properties of graphene are well known, the electrical performance of the material is limited by the contact resistance at the metal-graphene interface. In this study, we demonstrate the formation of "edge-contacted" graphene through the use of a controlled plasma processing technique that generates a bond between the graphene edge and the contact metal. This technique controls the edge structure of the bond and significantly reduces the contact resistance. This simple approach requires no additional post-processing and has been proven to be very effective. In addition, controlled pre-plasma processing was applied in order to produce CVD-graphene field effect transistors with an enhanced adhesion and improved carrier mobility. The contact resistance attained by using pre-plasma processing was 270 Ω µm, which is a decrease of 77%.
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Many studies on methane (CH4) and nitrous oxide (N2O) emissions from livestock industries have revealed that livestock production directly contributes to greenhouse gas (GHG) emissions through enteric fermentation and manure management, which causes negative impacts on animal environment sustainability. In the present study, three essential values for GHG emission were measured; i.e., i) maximum CH4 producing capacity at mesophilic temperature (37°C) from anaerobically stored manure in livestock category (B0,KM, Korean livestock manure for B0), ii) EF3(s) value representing an emission factor for direct N2O emissions from manure management system S in the country, kg N2O-N kg N(-1), at mesophilic (37°C) and thermophilic (55°C) temperatures, and iii) Nex(T) emissions showing annual N excretion for livestock category T, kg N animal(-1) yr(-1), from different livestock manure. Static incubation with and without aeration was performed to obtain the N2O and CH4 emissions from each sample, respectively. Chemical compositions of pre- and post-incubated manure were analyzed. Contents of total solids (% TS) and volatile solid (% VS), and the ratio of carbon to nitrogen (C/N) decrease significantly in all the samples by C-containing biogas generation, whereas moisture content (%) and pH increased after incubation. A big difference of total nitrogen content was not observed in pre- and post-incubation during CH4 and N2O emissions. CH4 emissions (g CH4 kg VS(-1)) from all the three manures (sows, layers and Korean cattle) were different and high C/N ratio resulted in high CH4 emission. Similarly, N2O emission was found to be affected by % VS, pH, and temperature. The B0,KM values for sows, layers, and Korean cattle obtained at 37°C are 0.0579, 0.0006, and 0.0828 m(3) CH4 kg VS(-1), respectively, which are much less than the default values in IPCC guideline (GL) except the value from Korean cattle. For sows and Korean cattle, Nex(T) values of 7.67 and 28.19 kg N yr(-1), respectively, are 2.5 fold less than those values in IPCC GL as well. However, Nex(T) value of layers 0.63 kg N yr(-1) is very similar to the default value of 0.6 kg N yr(-1) in IPCC GLs for National greenhouse gas inventories for countries such as South Korea/Asia. The EF3(s) value obtained at 37°C and 55°C were found to be far less than the default value.
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BACKGROUND: We recently reported that the interaction between Lyn and FcεRIß is indispensable for FcεRI-mediated human mast cell (MC) activation and that FcεRIß functions as an amplifier of FcεRI-mediated activation signal. Some of FcεRIß in cytoplasm appeared not to be co-localized with FcεRIα. The function of FcεRIß in the cytoplasm remains unknown. METHODS: The localization of FcεRIß and FcεRIα in giant papillae specimens from patients with allergic keratoconjunctivitis and of FcεRIß, FcεRIα, and Lyn in cultured human MCs was examined using confocal microscopy. FcεRIß was overexpressed using an adenovirus vector system. Mediators were measured by enzyme immunoassays or enzyme-linked immunosorbent assays. RESULTS: In the subepithelial region, FcεRIß was mainly localized in the cell membrane of MCs. In the perivascular region, FcεRIß expression was scattered throughout the cytoplasm and in the cell membrane of MCs. Overexpression of FcεRIß in MCs mainly increased its cytoplasmic expression and slightly up-regulated cell surface FcεRI expression. However, overexpression of FcεRIß in MCs resulted in down-regulation of the tyrosine phosphorylation levels of FcεRIß and Syk and down-regulation of the Ca(2+) influx soon after FcεRI aggregation and then resulted in down-regulation of degranulation, PGD2 synthesis, and production of a set of cytokines. This negative regulatory effect may be due to inhibition of the redistribution of Lyn to small patches within the plasma membrane. CONCLUSION: Cytoplasmic FcεRIß, which is not co-localized with FcεRIα, may function as a negative regulator, as it can capture important signalling molecules such as Lyn.
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Sinalização do Cálcio , Regulação para Baixo , Hipersensibilidade/metabolismo , Ceratoconjuntivite/metabolismo , Mastócitos/metabolismo , Receptores de IgE/biossíntese , Adulto , Linhagem Celular , Citoplasma , Feminino , Humanos , Hipersensibilidade/imunologia , Hipersensibilidade/patologia , Peptídeos e Proteínas de Sinalização Intracelular/imunologia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Ceratoconjuntivite/imunologia , Ceratoconjuntivite/patologia , Masculino , Mastócitos/imunologia , Mastócitos/patologia , Proteínas Tirosina Quinases/imunologia , Proteínas Tirosina Quinases/metabolismo , Receptores de IgE/imunologia , Quinase Syk , Quinases da Família src/imunologia , Quinases da Família src/metabolismoRESUMO
A merenda escolar visa oferecer um alimento seguro e saudável para os alunos, e por isso é essencial o constante monitoramento das condições de produção dos alimentos servidos. Objetivos: O presente trabalho refere-se à investigação das condições higiênico-sanitárias na produção da merenda escolar em uma escola estadual atendida pelo Programa Nacional de Alimentação Escolar - PNAE, na região do Triângulo Mineiro.
RESUMO
BACKGROUND: FcεRIß reportedly functions as an amplifier of the FcεRIγ-mediated activation signal using a reconstitution system. However, the amplification mechanisms in human mast cells (MCs) are poorly understood. We previously reported the hyperexpression of FcεRIß of MCs in giant papillae from vernal keratoconjunctivitis patients, compared with that in conjunctivae from nonallergic conjunctivitis patients. Elucidation of the molecular mechanisms of the amplification induced by FcεRIß should provide new targets for novel therapeutic interventions. The aim is to understand in greater details the function of FcεRIß in human MC FcεRI expression and signaling. METHODS: FcεRIß and Lyn expression was reduced using a lentiviral shRNA silencing technique. Localization of Lyn and FcεRIß in cultured MCs was examined by confocal microscopic analysis. Mediators were measured by ELISAs. RESULTS: The diminution of FcεRIß significantly downregulated cell surface FcεRI expression and FcεRI-mediated mediator release/production. The downregulation of FcεRI-mediated degranulation was not only due to the decrease in FcεRI expression. The diminution of FcεRIß inhibited the redistribution of Lyn within the cell membrane following IgE sensitization. The diminution of Lyn in MCs significantly downregulated FcεRI-mediated degranulation. The recombinant cell-penetrating forms of phosphorylated FcεRIß immunoreceptor tyrosine-based activation motif (ITAM) for intracellular delivery disturbed the interaction between Lyn and phosphorylated endogenous FcεRIß ITAM, resulted in inhibiting IgE-dependent histamine release from MCs in vitro and from giant papillae specimens ex vivo. CONCLUSION: The interaction between Lyn and FcεRIß is indispensable for FcεRI-mediated human MC activation, and specific inhibition of the interaction may represent a new therapeutic strategy for the treatment of human allergic diseases.
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Mastócitos/imunologia , Receptores de IgE/imunologia , Quinases da Família src/metabolismo , Adulto , Degranulação Celular/imunologia , Células Cultivadas , Regulação para Baixo , Humanos , Receptores de IgE/metabolismo , Transdução de SinaisRESUMO
OBJECTIVES: The antiphospholipid syndrome (APS) is characterized by the presence of circulating antiphospholipid antibodies (aPLs), is a leading cause for thromboembolic events, repeated miscarriage, fetal loss and is a major risk factor for fetal growth restriction (FGR) and preeclampsia. In human, anti-ß2 glycoprotein I (aß2GPI) antibody is one of the aPLs and considered to be a specific and important marker for APS. However, pathophysiological changes induced by aß2GPI antibodies in FGR are largely unknown. METHODS: In the present study, we developed a murine FGR model induced by multiple injections of WBCAL-1, a well-characterized mouse aß2GPI monoclonal antibody. RESULTS: Administration of WBCAL-1, but not the isotype control antibody and saline, into pregnant mice specifically decreased the size of fetuses and placentas without affecting the number of delivered pups. Also, a significant increase in urinary albumin and electron microscopic changes, such as splitting layers of basal membranes in the placental labyrinth and rearrangement of pores in glomerular endothelial cells, were observed in WBCAL-1 treated mice. WBCAL-1 injection did not induce any changes in blood pressure and typical parameters of blood thromboembolic symptoms. Furthermore, FcRγ deficiency protected the fetuses from aß2GPI antibody-induced injuries. CONCLUSIONS: Our present findings suggest that proteinuria is a symptom associated with APS-related FGR with placental and renal tissue injuries, and that FcRγ might be a molecular target for prevention of aß2GPI antibody-mediated obstetrical pathologies.
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Anticorpos Monoclonais/administração & dosagem , Retardo do Crescimento Fetal/imunologia , Receptores de IgG/fisiologia , beta 2-Glicoproteína I/imunologia , Animais , Anticorpos Antifosfolipídeos/imunologia , Síndrome Antifosfolipídica/imunologia , Síndrome Antifosfolipídica/urina , Modelos Animais de Doenças , Feminino , Retardo do Crescimento Fetal/prevenção & controle , Retardo do Crescimento Fetal/urina , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Knockout , Camundongos Nus , Microscopia Eletrônica , Placenta/imunologia , Placenta/patologia , Gravidez , Proteinúria , Receptores de IgG/deficiênciaRESUMO
Cambodia, a country of 14 million inhabitants, was devastated during the Khmer Rouge period and thereafter. The resources of treatment are rare: only one radiotherapy department, renovated in 2003, with an old cobalt machine; few surgeons trained to operate on cancer patients; no hematology; no facilities to use intensive chemotherapy; no nuclear medicine department and no palliative care unit. Cervical cancer incidence is one of the highest in the world, while in men liver cancer ranks first (20% of all male cancers). Cancers are seen at stage 3 or 4 for 70% of patients. There is no prevention program - only a vaccination program against hepatitis B for newborns - and no screening program for cervical cancer or breast cancer. In 2010, oncology, recognized as a full specialty, was created to train the future oncologists on site at the University of Phnom Penh. A new National Cancer Center will be built in 2013 with modern facilities for radiotherapy, medical oncology, hematology and nuclear medicine. Cooperation with foreign countries, especially France, and international organizations has been established and is ongoing. Progress is occurring slowly due to the shortage of money for Cambodian institutions and the lay public.
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Oncologia/educação , Oncologia/organização & administração , Neoplasias/epidemiologia , Camboja/epidemiologia , Atenção à Saúde , Feminino , Programas Governamentais , Humanos , Masculino , Neoplasias/diagnóstico , Neoplasias/terapiaRESUMO
Thirty-five available feeds were fermented in vitro in order to investigate their soluble total organic carbon (TOCs) and methane (CH4) production rate. A fermentation reactor was designed to capture the CH4 gas emitted and to collect liquor from the reactor during in vitro fermentation. The results showed that CH4 production rate greatly varied among feeds with different ingredients. The lowest CH4-producing feeds were corn gluten feed, brewer's grain, and orchard grass among the energy, protein, and forage feed groups, respectively. Significant differences (p<0.05) were found in digestibility, soluble total organic carbon (TOCs), and CH4 emissions among feeds, during 48 h of in vitro fermentation. Digestibility and TOCs was not found to be related due to different fermentation pattern of each but TOCs production was directly proportional to CH4 production (y = 0.0076x, r(2) = 0.83). From this in vitro study, TOCs production could be used as an indirect index for estimation of CH4 emission from feed ingredients.
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In order to investigate the effect of physical forms of starter diets on performance, weaning age, nutrient digestibility and rumen biochemical factors, 24 female of neonatal Brown Swiss calves (average body weight of 39.5±1.2 kg) were randomly assigned to three treatments. Dietary treatments were mashed (MS), pelleted (PS), and texturized (TS) starter using 8 calves from birth till 90 days of age in each treatment. Diets were formulated to be iso-nitrogenous with 21% crude protein. Based on the experimental results, calves that received PS and TS diets, had significant higher average daily gain (ADG) than those receiving MS (p<0.01). Dry matter intake in calves fed PS and TS was greater than calves fed MS (p<0.05), but there was no significant difference in feed efficiency. Treatments had no effect on initiation of rumination. Weaning age of calves in MS was longer than the other two treatments (p<0.05). Crude protein and organic matter digestibility in MS treated calves were lower than other treatments (p<0.05). No differences were observed in neutral detergent fiber (NDF) and ash digestibility among treatments (p>0.05). Ruminal pH was higher (p<0.01) in MS than the other groups, but ruminal ammonia (g/dl) concentration was not different among the treatments. Body measurements such as body length, pin width, hip width, pin to hip length, size of metacarpus and metatarsus bones, hip height, wither height, stomach size and heart girth were not significantly different among the treatments. Overall, it is concluded that starter diets in the form of pellet and texture can improve performance in neonatal Brown Swiss calves compared to the mashed form.
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A new real-time control strategy using moving slope changes of oxidation-reduction potential (ORP)- and pH(mV)-time profiles was designed. Its effectiveness was evaluated by operating a farm-scale sequencing batch reactor (SBR) process using the strategy. The working volume of the SBR was 18 m(3), and the volumetric loading rate of influent was 1 m(3) cycle(-1). The SBR process comprised six phases: feeding â anoxic â anaerobic â aerobic â settle â discharge. The anoxic and aerobic phases were controlled by the developed real-time control strategy. The nitrogen break point (NBP) in the pH(mV)-time profile and the nitrate knee point (NKP) in the ORP-time profile were designated as real-time control points for the aerobic and anoxic phases, respectively. Through successful real-time control, the duration of the aerobic and anoxic phases could be optimized and this resulted in very high N removal and a flexible hydraulic retention time. Despite the large variation in the loading rate (0.5-1.8 kg NH(4)-N m(-3) cycle(-1)) due to influent strength fluctuation, complete removal of NH(4)-N (100%) was always achieved. The removal efficiencies of soluble nitrogen (NH(4)-N plus NO(x)-N), soluble total organic carbon, and soluble chemical oxygen demand were 98%, 90%, and 82%, respectively. Monitoring the ORP and pH(mV) revealed that pH(mV) is a more reliable control parameter than ORP for the real-time control of the oxic phase. In some cases, a false NBP momentarily appeared in the ORP-time profile but was not observed in the pH(mV)-time profile. In contrast, ORP was more the reliable control parameter for NKP detection in the anoxic phase, since the appearance of NKP in the pH(mV)-time profile was sometimes vague.
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Nitrogênio/isolamento & purificação , Eliminação de Resíduos Líquidos/métodos , Animais , Concentração de Íons de Hidrogênio , Oxirredução , Esgotos , SuínosRESUMO
The effects of electric voltage and NaCl concentration on the removal of pollutants in swine wastewater were investigated to determine the optimum operation conditions for a designed electrolysis process. An up-flow electrolytic reactor was fabricated from Plexiglas, and one titanium anode coated with iridium oxide (IrO(2)) and two stainless steel cathodes were installed in it. The anode surface area was 80 cm(2)/L and the hydraulic retention time (HRT) was 6h. The results indicated that the pollutant removal was highly proportional to the electric voltage and removal could be enhanced by adding NaCl. The removal efficiencies of NH(4)-N, soluble nitrogen (NH(4)-N plus NO(x)-N), soluble total organic carbon (STOC), and color were proportional to the NaCl level up to 0.05% NaCl level, beyond which no further enhancement in removal was observed. However, such a tendency was not observed in the case of PO(4)-P removal. The obtained results indicate that 7 V and 0.05% (8.56 mM) NaCl level would be the optimum conditions for the designed electrolysis process. Under these conditions, the average removal efficiencies of NH(4)-N, soluble nitrogen, PO(4)-P, STOC, and color were 99%, 94%, 59%, 64%, and 93%, respectively.
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Eletricidade , Resíduos Industriais , Cloreto de Sódio/análise , Poluentes da Água , Animais , SuínosRESUMO
The feasibility of real-time control of the oxic phase using the pH (mV)-time profile in a sequencing batch reactor for swine wastewater treatment was evaluated, and the characteristics of the novel real-time control strategies were analyzed in two different concentrated wastewaters. The nitrogen break point (NBP) on the moving slope change (MSC) of the pH (mV) was designated as a real-time control point, and a pilot-scale sequencing batch reactor (18 m(3)) was designed to fulfill the objectives of the study. Successful real-time control using the developed control strategy was achieved despite the large variations in the influent strength and the loading rate per cycle. Indeed, complete and consistent removal of NH4-N (100% removal) was achieved. There was a strong positive correlation (r(2)=0.9789) between the loading rate and soluble total organic carbon (TOCs) removal, and a loading rate of 100 g/m(3)/cycle was found to be optimum for TOCs removal. Experimental data showed that the real-time control strategy using the MSC of the pH (mV)-time profile could be utilized successfully for the removal of nitrogen from swine wastewater. Furthermore, the pH (mV) was a more reliable real-time control parameter than the oxidation-reduction potential (ORP) for the control of the oxic phase. However, the nitrate knee point (NKP) appeared more consistently upon the completion of denitrification on the ORP-time profile than on the pH (mV)-time profile.
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Eliminação de Resíduos Líquidos/métodos , Purificação da Água/métodos , Criação de Animais Domésticos , Animais , Reatores Biológicos , Carbono/química , Carbono/isolamento & purificação , Desenho de Equipamento , Humanos , Concentração de Íons de Hidrogênio , Oxirredução , Projetos Piloto , Suínos , Fatores de Tempo , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/isolamento & purificaçãoRESUMO
A series of experiments were performed to study the effects of magnesium (Mg) and phosphate (PO(4)) addition on the decomposition of organic matter and struvite formation during the composting of swine manure. In these experiments, different amounts of magnesium chloride (MgCl(2)) with or without PO(4) salts were added to the samples, and the optimum molar ratio of Mg and PO(4) to the total nitrogen (TN) in swine manure was studied. The temperature profiles revealed that no organic matter was decomposed when 0.1M or more Mg and PO(4) salts were added and that when 0.05 M ratio of Mg and PO(4) salts was added, the addition inhibited the composting process. However, the thermophilic condition was readily established if only Mg salt was added. Further, the addition of only Mg salt easily established an optimum thermophilic condition even at a higher level. The highest amount of NH(3) was emitted when no Mg or PO(4) salts was added, and the rate of NH(3) emission was inversely proportional to the salt level. The orthophosphate/total phosphorus ratio (OP/TP) proportionally increased with the PO(4) amount added before composting but decreased after composting. In contrast, when only Mg was added, the OP/TP ratio proportionally decreased before composting and increased after composting. However, when more than 0.075 molar ratio of Mg was added, the OP/TP ratio decreased after composting; this result was identical to that obtained when both Mg and PO(4) salts were added. The decrease in the OP/TP ratio before or after composting could be due to the formation of magnesium ammonium phosphate (MAP) crystals. The study revealed that adding less than 0.05 M of both Mg and PO(4) salt or more than approximately 0.07 molar ratio of Mg with regard to the TN content was acceptable for the proper decomposition of organic matters and the continuous formation of struvite during the composting of swine manure.
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Magnésio/química , Esterco , Fosfatos/química , Eliminação de Resíduos/métodos , Solo , Amônia , Animais , Cinética , Compostos de Magnésio , Estruvita , SuínosRESUMO
A significant increase of mRNA expression of thymic stromal lymphopoietin (TSLP) has been reported in the bronchial mast cells (MCs) of asthmatic subjects; however, the mechanism underlying the upregulation of TSLP mRNA and protein remains unknown. FcepsilonRI-mediated activation of human MCs upregulated TSLP mRNA expression by 5.2+/-2.9-fold, while activation of the MCs using lipopolysaccharide and polyriboinosinic:polyribocytidylic acid failed to upregulate TSLP. Stimulation of MCs with interleukin (IL)-4 alone did not affect the TSLP mRNA expression, while pre-incubation of MCs with IL-4 for 48 h significantly enhanced the FcepsilonRI-mediated TSLP mRNA expression (by 53.7+/-15.9-fold; p<0.05) and the amount of TSLP in the cell pellets increased significantly from 23.4+/-4.3 pg mL(-1) to 121.5+/-3.7 pg mL(-1) (p<0.0001). However, the released TSLP was rapidly degraded by proteases that were released by MCs. We identified the population of cells expressing TSLP in the lungs of 16 asthmatic and 11 control subjects by immunohistochemistry. The percentage of TSLP-positive MCs in the total population of MCs was significantly increased in asthmatic airways (p<0.0001). Thus, MCs are able to store TSLP intracellularly and to produce TSLP following aggregation of FcepsilonRI in the presence of IL-4.
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Brônquios/metabolismo , Citocinas/metabolismo , Interleucina-4/metabolismo , Mastócitos/citologia , Receptores de IgE/metabolismo , Mucosa Respiratória/metabolismo , Adulto , Asma/metabolismo , Estudos de Casos e Controles , Feminino , Humanos , Imuno-Histoquímica/métodos , Leucócitos Mononucleares/citologia , Masculino , Pessoa de Meia-Idade , Linfopoietina do Estroma do TimoRESUMO
BACKGROUND: Basophils are an active participant in the pathogenesis of local inflammation in allergic diseases such as asthma, but it is not fully known how basophil activation is regulated in inflamed tissue. OBJECTIVE: In order to clarify the control mechanisms of basophil activation in chronic inflammation and at remodeling sites, we analyzed the effects of fibroblast-derived cytokines, stem cell factor (SCF), and insulin-like growth factor-I (IGF-I) on basophils. METHODS: The effects of SCF and IGF-I on degranulation and surface activation marker expression by basophils were assessed and compared. RESULTS: SCF enhanced human basophil histamine release elicited by some, but not all, secretagogues; degranulation in response to IgE- or FcepsilonRI-mediated stimulation and 12-o-tetradecanoyl-phorbol-13-acetate (TPA) was enhanced by SCF. SCF slightly enhanced ionophore A23187-induced histamine release by basophils from some donors, but it failed to affect the release elicited by monocyte chemoattractant protein-1 (MCP-1), formylmethionyl-leucyl-phenylalanine (FMLP) or C5a. The repertoire of secretagogues responsive to SCF was similar to that of IGF-I. Expression levels of both CD11b and CD69 markers were significantly enhanced by the combination of SCF and IGF-I. CONCLUSIONS: These results suggest that SCF and IGF-I may modify the activation of basophils in a similar and/or synergistic fashion. Interaction of basophils with these cytokines might be involved in the pathogenesis of local inflammation and the remodeling process in asthma.
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Antígenos CD/metabolismo , Antígenos de Diferenciação de Linfócitos T/metabolismo , Basófilos/imunologia , Antígeno CD11b/metabolismo , Degranulação Celular/efeitos dos fármacos , Liberação de Histamina/efeitos dos fármacos , Fator de Crescimento Insulin-Like I/farmacologia , Fator de Células-Tronco/farmacologia , Antígenos CD/imunologia , Antígenos de Diferenciação de Linfócitos T/imunologia , Basófilos/efeitos dos fármacos , Basófilos/metabolismo , Antígeno CD11b/efeitos dos fármacos , Antígeno CD11b/imunologia , Humanos , Fator de Crescimento Insulin-Like I/imunologia , Lectinas Tipo C , Proteínas Recombinantes/farmacologia , Fator de Células-Tronco/imunologiaRESUMO
BACKGROUND: Dapsone (4,4'-diaminodiphenyl sulphone) is a powerful therapeutic tool in many skin diseases including neutrophilic dermatoses. The drug has an outstanding therapeutic efficacy against many skin diseases characterized by neutrophil-rich infiltrates; however, mechanisms of its action are poorly understood. OBJECTIVES: We investigated the effects of dapsone on respiratory and secretory functions of human neutrophils triggered by the chemotactic peptide N-formyl-L-methionyl-L-leucyl-L-phenylalanine (fMLP), the physiological agonist C5a, and phorbol myristate acetate (PMA). METHODS: Human neutrophils were isolated from venous blood obtained from healthy donors. We detected extracellular production of superoxide (O(2) (-)) by cytochrome C reduction assay, and intracellular production of O(2) (-) by flow cytometry. Neutrophil elastase release was measured by the cleavage of the specific elastase substrate N-methoxysuccinyl-Ala-Ala-Pro-Val-p-nitroanilide. Measurement of cytosolic free calcium concentration was performed using the calcium-reactive fluorescence probe, Fluo-3. RESULTS: Dapsone suppressed intra- and extracellular production of O(2) (-) and elastase release triggered by fMLP and C5a, but not by PMA. Both fMLP and C5a signalled the above pathways by inducing calcium influx, but PMA functions bypassed calcium influx. Dapsone was capable of antagonizing the induction of calcium influx. CONCLUSIONS: These findings suggest that one mechanism of the anti-inflammatory action of dapsone is inhibition of calcium-dependent functions of neutrophils including release of tissue-damaging oxidants and proteases in the affected skin.
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Anti-Inflamatórios não Esteroides/farmacologia , Dapsona/farmacologia , Neutrófilos/efeitos dos fármacos , Elastase Pancreática/metabolismo , Superóxidos/metabolismo , Cálcio/antagonistas & inibidores , Cálcio/metabolismo , Cálcio/farmacologia , Células Cultivadas , Complemento C5a/antagonistas & inibidores , Complemento C5a/farmacologia , Relação Dose-Resposta a Droga , Humanos , N-Formilmetionina Leucil-Fenilalanina/antagonistas & inibidores , N-Formilmetionina Leucil-Fenilalanina/farmacologia , Ativação de Neutrófilo/efeitos dos fármacos , Neutrófilos/metabolismo , Explosão Respiratória/efeitos dos fármacos , Acetato de Tetradecanoilforbol/antagonistas & inibidores , Acetato de Tetradecanoilforbol/farmacologiaRESUMO
BACKGROUND: Activation of mast cells by lipopolysaccharide (LPS) results in the production of TNF-alpha and IL-13. TNF-alpha and IL-13 are key mediators in the development of neutrophilic and allergic inflammation, respectively. LPS-induced TNF-alpha and IL-13 production in mast cells has been reported to be mediated by Toll-like receptor 4 (TLR4) signalling, but differences in signal transduction mechanisms leading to the production of these cytokines are not clearly defined. OBJECTIVE: We investigated the molecular mechanisms responsible for LPS-induced TNF-alpha and IL-13 production in mast cells. METHODS: TNF-alpha and IL-13 production by LPS was assessed by transfecting RBL-2H3 cells with dominant-negative (DN) expression vectors. RESULTS: Transfection of RBL-2H3 cells with plasmids encoding DN mutants of myeloid differentiation protein (MyD88) and TNFR-associated factor (TRAF6) inhibited both LPS-induced TNF-alpha and IL-13 production. IkappaBalpha-DN inhibited LPS-induced production of TNF-alpha, but not IL-13. We also found that inhibition of p38 kinase suppressed both TNF-alpha and IL-13 induction by LPS, and inhibition of JNK reduced IL-13 production, but not TNF-alpha. Furthermore, we found that protein kinase R (PKR) was activated by LPS in these cells. Treatment with 2-aminopurine, a PKR inhibitor, attenuated LPS-induced nuclear factor-kappaB activation and TNF-alpha production, whereas inhibition of PKR had little effect on IL-13 production. CONCLUSION: These findings indicate that the production of TNF-alpha and IL-13 by LPS required TLR4/MyD88/TRAF6 signalling as a common pathway of mast cell-mediated inflammation. We furthermore found that TNF-alpha and IL-13 production were differentially regulated by signalling cascades through PKR and mitogen-activated protein kinases downstream of TRAF6 in mast cells.
Assuntos
Interleucina-13/biossíntese , Lipopolissacarídeos/imunologia , Mastócitos/imunologia , Transdução de Sinais/imunologia , Fator de Necrose Tumoral alfa/biossíntese , Proteínas Adaptadoras de Transdução de Sinal , Animais , Antígenos de Diferenciação/imunologia , Células Cultivadas , Hipersensibilidade/imunologia , Proteínas I-kappa B/imunologia , Proteínas Quinases JNK Ativadas por Mitógeno/imunologia , MAP Quinase Quinase 4 , Quinases de Proteína Quinase Ativadas por Mitógeno/imunologia , Fator 88 de Diferenciação Mieloide , NF-kappa B/imunologia , Receptores Imunológicos/imunologia , Fator 6 Associado a Receptor de TNF/imunologia , Transfecção/métodos , eIF-2 Quinase/imunologia , Proteínas Quinases p38 Ativadas por Mitógeno/imunologiaRESUMO
BACKGROUND: Fc alpha receptor (FcalphaR; CD89) is the receptor for Fc portion of IgA in various cells, and displays various immunological responses on binding. It is important to analyze the mesangial functions via FcalphaR in the pathogenesis of IgA nephropathy. However, it is still controversial whether FcalphaR is expressed on mesangial cells. To assess biological functions of FcalphaR on the mesangial cells, we established mesangial transfectants that expressed FcalphaR with or without FcRgamma chain that is a common signaling molecule of FcRs. The production of monocyte chemoattractant protein-1 (MCP-1) by mesangial cells is known to contribute to cellular infiltration into glomeruli and subsequent glomerular injuries. METHODS: Murine mesangial cell lines (SV40 MES 13) were transfected with cDNA of the human FcalphaR. Furthermore, we co-transfected some of the FcalphaR transfectants with cDNA of human FcRgamma chain. The tyrosine phosphorylation of the intra-mesangial proteins after FcalphaR cross-linking was examined by immunoprecipitation. MCP-1 production from each transfectant stimulated with heat aggregated IgA was determined by sandwich ELISA. RESULTS: Two kinds of mesangial transfectants stably expressed human FcalphaR with or without FcRgamma chain (FcalphaR(+), FcalphaR(+)/gamma(+)). Phosphorylation of FcRgamma chain and syk kinase was detected in FcalphaR(+) and FcalphaR(+)/gamma(+) cells, but not in untransfected cells. Aggregated IgA induced significantly higher MCP-1 production in FcalphaR(+)/gamma(+) than those in FcalphaR(+) or untransfected control. CONCLUSIONS: Present study demonstrated that FcalphaR and FcRgamma chain could be reconstituted in mesangial cells and mediated MCP-1 production by aggregated IgA in a dose-dependent manner. Current data would argue that FcalphaR can be activated in mesangial cells through their own machinery, although underlying mechanisms for FcalphaR induction in mesangial cells remain unclear.
Assuntos
Antígenos CD/metabolismo , Quimiocina CCL2/biossíntese , Mesângio Glomerular/metabolismo , Receptores Fc/metabolismo , Animais , Células Cultivadas , Fenômenos Químicos , Físico-Química , Quimiocina CCL2/genética , Precursores Enzimáticos/biossíntese , Precursores Enzimáticos/genética , Mesângio Glomerular/citologia , Peptídeos e Proteínas de Sinalização Intracelular , Camundongos , Fosforilação , Proteínas Tirosina Quinases/biossíntese , Proteínas Tirosina Quinases/genética , RNA/biossíntese , RNA/genética , Quinase Syk , Transfecção , Tirosina/metabolismoRESUMO
BACKGROUND: Atopic dermatitis is a chronic, relapsing inflammatory disorder characterized by pruritic and eczematous skin lesions. Transforming growth factor (TGF)-beta1 has been implicated in the suppression of inflammatory responses. OBJECTIVE: The purpose of this study is to determine whether TGF-beta1 suppresses skin lesions in a mouse model of atopic dermatitis. METHODS: We used the NC/Nga strain of mice as an in vivo model of atopic dermatitis. The effects of exogenous TGF-beta1 on atopic dermatitis-like skin lesions in NC/Nga mice were evaluated clinically, histologically and immunologically. RESULTS: Subcutaneous injection of recombinant TGF-beta1 macroscopically suppressed eczematous skin lesions in NC/Nga mice associated with reduced serum immunoglobulin E (IgE) levels. Histological analysis showed that TGF-beta1 significantly inhibited the infiltration of inflammatory cells such as mast cells and eosinophils into the skin of NC/Nga mice. Spontaneous interferon (IFN)-gamma production from splenocytes of NC/Nga mice was down-regulated by the treatment with TGF-beta1 and neutralizing antibody against IFN-gamma inhibited skin lesions in NC/Nga mice. The inhibitory effect of TGF-beta1 on the skin lesions lasted at least 1 week after cessation of the treatment. CONCLUSION: These findings indicate that TGF-beta1 suppressed atopic dermatitis-like skin lesions in NC/Nga mice at least in part through down-regulation of IFN-gamma. These results suggest that TGF-beta1 may have a therapeutic potential for atopic dermatitis.
Assuntos
Dermatite Atópica/patologia , Fator de Crescimento Transformador beta/farmacologia , Animais , Anticorpos/farmacologia , Dermatite Atópica/metabolismo , Modelos Animais de Doenças , Imunoglobulina E/análise , Interferon gama/antagonistas & inibidores , Interferon gama/imunologia , Interferon gama/metabolismo , Camundongos , Camundongos Endogâmicos , Proteínas Recombinantes/farmacologia , Baço/metabolismo , Baço/patologia , Fator de Crescimento Transformador beta1RESUMO
The structural features most conducive to complexation of the alkali metal ions Li(+), Na(+), and K(+) in a series of constrained inositol orthoformate derivatives have been probed in solution, in the solid state, and in the gas phase by electrospray ionization mass spectrometry. The eight spirotricyclic polyethers differ in the size of the rings containing the potentially ligating oxygen atoms. Although the ring sizes have been limited to three to five atoms inclusively, the combinations of oxirane, oxetane, and tetrahydrofuran are rather extensive and consist of many options. The overall trend for lithium ion affinity is [5.5.5] > [ 5.5.4] > [4.4.4] > [5.5.3] > [5.4.3] > [4.4.3] > [1.1.1] > [3.3.1], an ordering that correlates with the differing polarizabilities of the oxygen atoms, ease of alignment of the nonbonded electron pairs, and the overall size of the ligand as gauged by nonbonded O......O distances.