994 resultados para BETA-ACIDS


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BACKGROUND Adherence to interferon β-1b (INFβ-1b) therapy is essential to maximize the beneficial effects of treatment in multiple sclerosis (MS). For that reason, the main objectives of this study are to assess adherence to INFβ-1b in patients suffering from MS in Spain, and to identify the factors responsible for adherence in routine clinical practice. METHODOLOGY/PRINCIPAL FINDINGS This was an observational, retrospective, cross-sectional study including 120 Spanish patients with MS under INFβ-1b treatment. Therapeutic adherence was assessed with Morisky-Green test and with the percentage of doses received. The proportion of adherent patients assessed by Morisky-Green test was 68.3%, being indicative of poor adherence. Nevertheless, the percentage of doses received, which was based on the number of injected medication, was 94.3%. The main reason for missing INFβ-1b injections was forgetting some of the administrations (64%). Therefore, interventions that diminish forgetfulness might have a positive effect in the proportion of adherent patients and in the percentage of doses received. In addition, age and comorbidities had a significant effect in the number of doses injected per month, and should be considered in the management of adherence in MS patients. CONCLUSION/SIGNIFICANCE Among all the available methods for assessing adherence, the overall consumption of the intended dose has to be considered when addressing adherence.

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BACKGROUND Multiple sclerosis (MS) is a multifactorial disease with a genetic basis. The strongest associations with the disease lie in the Human Leukocyte Antigen (HLA) region. However, except for the DRB1*15:01 allele, the main risk factor associated to MS so far, no consistent effect has been described for any other variant. One example is HLA-DRB1*03:01, with a heterogeneous effect across populations and studies. We postulate that those discrepancies could be due to differences in the diverse haplotypes bearing that allele. Thus, we aimed at studying the association of DRB1*03:01 with MS susceptibility considering this allele globally and stratified by haplotypes. We also evaluated the association with the presence of oligoclonal IgM bands against myelin lipids (OCMB) in cerebrospinal fluid. METHODS Genotyping of HLA-B, -DRB1 and -DQA1 was performed in 1068 MS patients and 624 ethnically matched healthy controls. One hundred and thirty-nine MS patients were classified according to the presence (M+, 58 patients)/absence (M-, 81 patients) of OCMB. Comparisons between groups (MS patients vs. controls and M+ vs. M-) were performed with the chi-square test or the Fisher exact test. RESULTS Association of DRB1*03:01 with MS susceptibility was observed but with different haplotypic contribution, being the ancestral haplotype (AH) 18.2 the one causing the highest risk. Comparisons between M+, M- and controls showed that the AH 18.2 was affecting only M+ individuals, conferring a risk similar to that caused by DRB1*15:01. CONCLUSIONS The diverse DRB1*03:01-containing haplotypes contribute with different risk to MS susceptibility. The AH 18.2 causes the highest risk and affects only to individuals showing OCMB.

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BACKGROUND AND AIM The genotype-phenotype interaction in drug-induced liver injury (DILI) is a subject of growing interest. Previous studies have linked amoxicillin-clavulanate (AC) hepatotoxicity susceptibility to specific HLA alleles. In this study we aimed to examine potential associations between HLA class I and II alleles and AC DILI with regards to phenotypic characteristics, severity and time to onset in Spanish AC hepatotoxicity cases. METHODS High resolution genotyping of HLA loci A, B, C, DRB1 and DQB1 was performed in 75 AC DILI cases and 885 controls. RESULTS The distributions of class I alleles A*3002 (P/Pc = 2.6E-6/5E-5, OR 6.7) and B*1801 (P/Pc = 0.008/0.22, OR 2.9) were more frequently found in hepatocellular injury cases compared to controls. In addition, the presence of the class II allele combination DRB1*1501-DQB1*0602 (P/Pc = 5.1E-4/0.014, OR 3.0) was significantly increased in cholestatic/mixed cases. The A*3002 and/or B*1801 carriers were found to be younger (54 vs 65 years, P = 0.019) and were more frequently hospitalized than the DRB1*1501-DQB1*0602 carriers. No additional alleles outside those associated with liver injury patterns were found to affect potential severity as measured by Hy's Law criteria. The phenotype frequencies of B*1801 (P/Pc = 0.015/0.42, OR 5.2) and DRB1*0301-DQB1*0201 (P/Pc = 0.0026/0.07, OR 15) were increased in AC DILI cases with delayed onset compared to those corresponding to patients without delayed onset, while the opposite applied to DRB1*1302-DQB1*0604 (P/Pc = 0.005/0.13, OR 0.07). CONCLUSIONS HLA class I and II alleles influence the AC DILI signature with regards to phenotypic expression, latency presentation and severity in Spanish patients.

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The effect of exendin-(9-39), a described antagonist of the glucagon-like peptide-1 (GLP-1) receptor, was evaluated on the formation of cAMP- and glucose-stimulated insulin secretion (GSIS) by the conditionally immortalized murine betaTC-Tet cells. These cells have a basal intracellular cAMP level that can be increased by GLP-1 with an EC50 of approximately 1 nM and can be decreased dose dependently by exendin-(9-39). This latter effect was receptor dependent, as a beta-cell line not expressing the GLP-1 receptor was not affected by exendin-(9-39). It was also not due to the endogenous production of GLP-1, because this effect was observed in the absence of detectable preproglucagon messenger RNA levels and radioimmunoassayable GLP-1. Importantly, GSIS was shown to be sensitive to this basal level of cAMP, as perifusion of betaTC-Tet cells in the presence of exendin-(9-39) strongly reduced insulin secretion. This reduction of GSIS, however, was observed only with growth-arrested, not proliferating, betaTC-Tet cells; it was also seen with nontransformed mouse beta-cells perifused in similar conditions. These data therefore demonstrated that 1) exendin-(9-39) is an inverse agonist of the murine GLP-1 receptor; 2) the decreased basal cAMP levels induced by this peptide inhibit the secretory response of betaTC-Tet cells and mouse pancreatic islets to glucose; 3) as this effect was observed only with growth-arrested cells, this indicates that the mechanism by which cAMP leads to potentiation of insulin secretion is different in proliferating and growth-arrested cells; and 4) the presence of the GLP-1 receptor, even in the absence of bound peptide, is important for maintaining elevated intracellular cAMP levels and, therefore, the glucose competence of the beta-cells.

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Non-bilayer phospholipid arrangements are three-dimensional structures that form when anionic phospholipids with an intermediate structure of the tubular hexagonal phase II are present in a bilayer of lipids. Antibodies that recognise these arrangements have been described in patients with antiphospholipid syndrome and/or systemic lupus erythematosus and in those with preeclampsia; these antibodies have also been documented in an experimental murine model of lupus, in which they are associated with immunopathology. Here, we demonstrate the presence of antibodies against non-bilayer phospholipid arrangements containing mycolic acids in the sera of lepromatous leprosy (LL) patients, but not those of healthy volunteers. The presence of antibodies that recognise these non-bilayer lipid arrangements may contribute to the hypergammaglobulinaemia observed in LL patients. We also found IgM and IgG anti-cardiolipin antibodies in 77% of the patients. This positive correlation between the anti-mycolic-non-bilayer arrangements and anti-cardiolipin antibodies suggests that both types of antibodies are produced by a common mechanism, as was demonstrated in the experimental murine model of lupus, in which there was a correlation between the anti-non-bilayer phospholipid arrangements and anti-cardiolipin antibodies. Antibodies to non-bilayer lipid arrangements may represent a previously unrecognised pathogenic mechanism in LL and the detection of these antibodies may be a tool for the early diagnosis of LL patients.

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Leishmaniasis is a neglected tropical disease. According to the World Health Organization, there are approximately 1.5-two million new cases of cutaneous leishmaniasis each year worldwide. Chemotherapy against leishmaniasis is based on pentavalent antimonials, which were developed more than a century ago. The goals of this study were to investigate the antileishmanial activity of diterpene acids in copaiba oil, as well as some possible targets of their action against Leishmania amazonensis. Methyl copalate and agathic, hydroxycopalic, kaurenoic, pinifolic and polyaltic acids isolated from Copaifera officinales oleoresins were utilised. Ultrastructural changes and the specific organelle targets of diterpenes were investigated with electron microscopy and flow cytometry, respectively. All compounds had some level of activity against L. amazonensis. Hydroxycopalic acid and methyl copalate demonstrated the most activity against promastigotes and had 50% inhibitory concentration (IC50) values of 2.5 and 6.0 µg/mL, respectively. However, pinifolic and kaurenoic acid demonstrated the most activity against axenic amastigote and had IC50 values of 3.5 and 4.0 µg/mL, respectively. Agathic, kaurenoic and pinifolic acid caused significant increases in plasma membrane permeability and mitochondrial membrane depolarisation of the protozoan. In conclusion, copaiba oil and its diterpene acids should be explored for the development of new antileishmanial drugs.

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In insulin-secreting cells, cytokines activate the c-Jun N-terminal kinase (JNK), which contributes to a cell signaling towards apoptosis. The JNK activation requires the presence of the murine scaffold protein JNK-interacting protein 1 (JIP-1) or human Islet-brain 1(IB1), which organizes MLK3, MKK7 and JNK for proper signaling specificity. Here, we used adenovirus-mediated gene transfer to modulate IB1/JIP-1 cellular content in order to investigate the contribution of IB1/JIP-1 to beta-cell survival. Exposure of the insulin-producing cell line INS-1 or isolated rat pancreatic islets to cytokines (interferon-gamma, tumor necrosis factor-alpha and interleukin-1beta) induced a marked reduction of IB1/JIP-1 content and a concomitant increase in JNK activity and apoptosis rate. This JNK-induced pro-apoptotic program was prevented in INS-1 cells by overproducing IB1/JIP-1 and this effect was associated with inhibition of caspase-3 cleavage. Conversely, reducing IB1/JIP-1 content in INS-1 cells and isolated pancreatic islets induced a robust increase in basal and cytokine-stimulated apoptosis. In heterozygous mice carrying a selective disruption of the IB1/JIP-1 gene, the reduction in IB1/JIP-1 content in happloinsufficient isolated pancreatic islets was associated with an increased JNK activity and basal apoptosis. These data demonstrate that modulation of the IB1-JIP-1 content in beta cells is a crucial regulator of JNK signaling pathway and of cytokine-induced apoptosis.

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Archaeological leather samples recovered from the ice field at the Schnidejoch Pass (altitude 2756 m amsl) in the western Swiss Alps were studied using optical, chemical molecular and isotopic (delta(13)C and delta(15)N of the bulk leather, and compound-specific delta(13)C analyses of the organic-solvent extracted fatty acids) methods to obtain insight into the origin of the leather and ancient tanning procedures. For comparison, leathers from modern native animals in alpine environment (red deer, goat, sheep, chamois, and calf/cow) were analyzed using the same approach. Optical and electron microscopically comparisons of Schnidejoch and modern leathers showed that the gross structure (pattern of collagen fibrils and intra-fibrils material) of archaeological leather had survived essentially intact for five millennia. The SEM studies of the hairs from the most important archaeological find, a Neolithic leather legging, show a wave structure of the hair cuticle, which is a diagnostic feature for goatskins. The variations of the bulk delta(13)C and delta(15)N values, and delta(13)C values of the main fatty acids are within the range expected for pre-industrial temperate C(3) environment. The archaeological leather samples contain a mixture of indigenous (from the animal) and exogenous plant/animal lipids. An important amount of waxy n-alkanes, n-alkan-1-ols and phytosterols (beta-sitosterol, sitostanol) in all samples, and abundant biomarker of conifers (nonacosan-10-01) in the legging leathers clearly indicate that the Neolithic people were active in a subalpine coniferous forest, and that they used an aqueous extract of diverse plant material for tanning leather. (C) 2010 Elsevier Ltd. All rights reserved.

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Amoxicillin, a low-molecular-weight compound, is able to interact with dendritic cells inducing semi-maturation in vitro. Specific antigens and TLR ligands can synergistically interact with dendritic cells (DC), leading to complete maturation and more efficient T-cell stimulation. The aim of the study was to evaluate the synergistic effect of amoxicillin and the TLR2, 4 and 7/8 agonists (PAM, LPS and R848, respectively) in TLR expression, DC maturation and specific T-cell response in patients with delayed-type hypersensitivity (DTH) reactions to amoxicillin. Monocyte-derived DC from 15 patients with DTH to amoxicillin and 15 controls were cultured with amoxicillin in the presence or absence of TLR2, 4 and 7/8 agonists (PAM, LPS and R848, respectively). We studied TLR1-9 gene expression by RT-qPCR, and DC maturation, lymphocyte proliferation and cytokine production by flow cytometry. DC from both patients and controls expressed all TLRs except TLR9. The amoxicillin plus TLR2/4 or TLR7/8 ligands showed significant differences, mainly in patients: AX+PAM+LPS induced a decrease in TLR2 and AX+R848 in TLR2, 4, 7 and 8 mRNA levels. AX+PAM+LPS significantly increased the percentage of maturation in patients (75%) vs. controls (40%) (p=0.036) and T-cell proliferation (80.7% vs. 27.3% of cases; p=0.001). Moreover, the combinations AX+PAM+LPS and AX+R848 produced a significant increase in IL-12p70 during both DC maturation and T-cell proliferation. These results indicate that in amoxicillin-induced maculopapular exanthema, the presence of different TLR agonists could be critical for the induction of the innate and adaptive immune responses and this should be taken into account when evaluating allergic reactions to these drugs.

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BACKGROUND The number of copies of the HLA-DRB1 shared epitope, and the minor alleles of the STAT4 rs7574865 and the PTPN22 rs2476601 polymorphisms have all been linked with an increased risk of developing rheumatoid arthritis. In the present study, we investigated the effects of these genetic variants on disease activity and disability in patients with early arthritis. METHODOLOGY AND RESULTS We studied 640 patients with early arthritis (76% women; median age, 52 years), recording disease-related variables every 6 months during a 2-year follow-up. HLA-DRB1 alleles were determined by PCR-SSO, while rs7574865 and rs2476601 were genotyped with the Taqman 5' allelic discrimination assay. Multivariate analysis was performed using generalized estimating equations for repeated measures. After adjusting for confounding variables such as gender, age and ACPA, the TT genotype of rs7574865 in STAT4 was associated with increased disease activity (DAS28) as compared with the GG genotype (β coefficient [95% confidence interval] = 0.42 [0.01-0.83], p = 0.044). Conversely, the presence of the T allele of rs2476601 in PTPN22 was associated with diminished disease activity during follow-up in a dose-dependent manner (CT genotype = -0.27 [-0.56- -0.01], p = 0.042; TT genotype = -0.68 [-1.64- -0.27], p = 0.162). After adjustment for gender, age and disease activity, homozygosity for the T allele of rs7574865 in STAT4 was associated with greater disability as compared with the GG genotype. CONCLUSIONS Our data suggest that patients with early arthritis who are homozygous for the T allele of rs7574865 in STAT4 may develop a more severe form of the disease with increased disease activity and disability.

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BACKGROUND & AIMS: The peroxisome proliferator-activated nuclear receptors (PPAR-alpha, PPAR-beta, and PPAR-gamma), which modulate the expression of genes involved in energy homeostasis, cell cycle, and immune function, may play a role in hepatic stellate cell activation. Previous studies focused on the decreased expression of PPAR-gamma in hepatic stellate cell activation but did not investigate the expression and role of the PPAR-alpha and -beta isotypes. The aim of this study was to evaluate the expression of the different PPARs during hepatic stellate cell activation in vitro and in situ and to analyze possible factors that might contribute to their expression. In a second part of the study, the effect of a PPAR-beta agonist on acute liver injury was evaluated. METHODS: The effects of PPAR isotype-specific ligands on hepatic stellate cell transition were evaluated by bromodeoxyuridine incorporation, gel shifts, immunoprecipitation, and use of antisense PPAR-beta RNA-expressing adenoviruses. Tumor necrosis factor alpha-induced PPAR-beta phosphorylation and expression was evaluated by metabolic labeling and by using specific P38 inhibitors. RESULTS: Hepatic stellate cells constitutively express high levels of PPAR-beta, which become further induced during culture activation and in vivo fibrogenesis. No significant expression of PPAR-alpha or -gamma was found. Stimulation of the P38 mitogen-activated protein kinase pathway modulated the expression of PPAR-beta. Transcriptional activation of PPAR-beta by L165041 enhanced hepatic stellate cell proliferation. Treatment of rats with a single bolus of CCl(4) in combination with L165041 further enhanced the expression of fibrotic markers. CONCLUSIONS: PPAR-beta is an important signal-transducing factor contributing to hepatic stellate cell proliferation during acute and chronic liver inflammation.

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To provide further insights into ruminant lipid digestion and metabolism, and into cis9, trans-11 18:2 synthesis, 12 growing Engadine lambs grazing either mountain pasture (2,250 m above sea level; n = 6) or lowland pasture (400 m above sea level; n = 6) were studied. Both pastures consisted exclusively of C-3 plants. Before the experiment, all animals grazed a common pasture for 6 wk. Grasses and perirenal adipose tissues of the sheep were analyzed for fatty acids by gas chromatography. Stable C-isotope ratios (delta C-13 values in % vs. the Vienna Pee Dee Belemnite standard) were determined in the composite samples by elemental analysis-isotope ratio mass spectrometry. The delta C-13 of the individual fatty acids were measured by gas chromatography-combustion-isotope ratio mass spectrometry. The delta C-13 value of the entire mountain pasture grass was -27.5% (SD 0.31), whereas that of the lowland pasture grass was -30.0% (SD 0.07). This difference was reflected in the perirenal adipose tissues of the corresponding sheep (P < 0.05), even though the delta C-13 values were less in the animals than in the grass. The delta C-13 values for cis-9 16:1 and cis-9 18:1 in perirenal fat differed between mountain and lowland lambs (P < 0.05). The 16:0 in the adipose tissue was enriched in C-13 by 5% compared with the dietary 16:0, likely as a result of partly endogenous synthesis. The d13C values of cis-9, trans-11 18:2 (cis-9, trans-11 CLA) in the adipose tissue were smaller than those of its dietary precursors, cis-9, cis-12 18:2 and cis-9, cis-12, cis-15 18:3; conversely, the delta C-13 values of trans-11 18:1 were not, suggesting that large proportions of perirenal cis-9, trans-11 18:2 were of endogenous origin and discrimination against C-13 occurred during Delta(9)-desaturation. The same discrimination was indicated by the isotopic shift between 16:0 and cis-9 16:1 in the mountain grazing group. Furthermore, the delta C-13 values of cis-9, trans-11 18:2 were smaller relative to the precursor fatty acids in the mountain lambs compared with the lowland group. This result suggests a reduced extent of biohydrogenation in lambs grazing on mountain grass in comparison with those grazing on lowland grass. This was supported by the smaller cis-9, trans-11 18:2 concentrations in total fatty acids found in the adipose tissues of the lowland lambs (P < 0.001). The results of this study demonstrate that natural differences between delta C-13 values of swards from different pastures and the adipose tissue fatty acids could be used as tracers in studies of lipid metabolism in ruminants.

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Connexin36 (Cx36) is specifically expressed in neurons and in pancreatic beta-cells. Cx36 functions as a critical regulator of insulin secretion and content in beta-cells. In order to identify the molecular mechanisms that control the beta-cell expression of Cx36, we initiated the characterization of the human 5' regulatory region of the CX36 gene. A 2043-bp fragment of the human CX36 promoter was identified from a human BAC library and fused to a luciferase reporter gene. This promoter region was sufficient to confer specific expression to the reporter gene in insulin-secreting cell lines. Within this 5' regulatory region, a putative neuron-restrictive silencer element conserved between rodent and human species was recognized and binds the neuron-restrictive silencing factor (NRSF/REST). This factor is not expressed in insulin-secreting cells and neurons; it functions as a potent repressor through the recruitment of histone deacetylase to the promoter of neuronal genes. The NRSF-mediated repression of Cx36 in HeLa cells was abolished by trichostatin A, confirming the functional importance of histone deacetylase activity. Ectopic expression, by viral gene transfer, of NRSF/REST in different insulin-secreting beta-cell lines induced a marked reduction in Cx36 mRNA and protein content. Moreover, mutations in the Cx36 neuron-restrictive silencer element relieved the low transcriptional activity of the human CX36 promoter observed in HeLa cells and in INS-1 cells expressing NRSF/REST. The data showed that cx36 gene expression in insulin-producing beta-cell lines is strictly controlled by the transcriptional repressor NRSF/REST indicating that Cx36 participates to the neuronal phenotype of the pancreatic beta-cells.

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The liver of C57BL/6 mice contains a major subset of CD4+8- and CD4-8- T cell receptor (TCR)-alpha/beta+ cells expressing the polymorphic natural killer NK1.1 surface marker. Liver NK1.1+TCR-alpha/beta+ (NK1+ T) cells require interaction with beta2-microglobulin-associated, major histocompatibility complex I-like molecules on hematopoietic cells for their development and have a TCR repertoire that is highly skewed to Vbeta8.2, Vbeta7, and Vbeta2. We show here that congenic C57BL/6.Vbeta(a) mice, which lack Vbeta8- expressing T cells owing to a genomic deletion at the Vbeta locus, maintain normal levels of liver NK1+ T cells owing to a dramatic increase in the proportion of cells expressing Vbeta7 and Vbeta2 (but not other Vbetas). Moreover, in C57BL/6 congenic TCR-V Vbeta3 and -Vbeta8.1 transgenic mice (which in theory should not express other Vbeta, owing to allelic exclusion at the TCR-beta locus), endogenous TCR-Vbeta8.2, Vbeta7, and Vbeta2 (but not other Vbetas) are frequently expressed on liver NK1+T cells but absent on lymph node T cells. Finally, when endogenous V beta expression is prevented in TCR-Vbeta3 and Vbeta8.1 transgenic mice (by introduction of a null allele at the C beta locus), the development of liver NK1+T cells is totally abrogated. Collectively, our data indicate that liver NK1+T cells have a stringent requirement for expression of TCR-Vbeta8.2, Vbeta7, or Vbeta2 for their development.

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T cell factor-1 (Tcf-1) is a transcription factor that binds to a sequence motif present in several T cell-specific enhancer elements. In Tcf-1-deficient (Tcf-1-/-) mice, thymocyte development is partially blocked at the transition from the CD4-8+ immature single-positive stage to the CD4+8+ double-positive stage, resulting in a marked decrease of mature peripheral T cells in lymph node and spleen. We report here that the development of most intestinal TCR gamma delta+ cells and liver CD4+ NK1.1+TCR alpha beta+ (NK1+T) cells, which are believed to be of extrathymic origin, is selectively impaired in Tcf-1-/- mice. In contrast, thymic and thymus-derived (splenic) TCR gamma delta+ cells are present in normal numbers in Tcf-1-/- mice, as are other T cell subsets in intestine and liver. Collectively, our data suggest that Tcf-1 is differentially required for the development of some extrathymic T cell subsets, including intestinal TCR gamma delta+ cells and liver CD4+ NK1+T cells.