561 research outputs found

    Increased glycation and oxidative damage to apolipoprotein B100 of LDL cholesterol in patients with type 2 diabetes and effect of metformin

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    OBJECTIVE The aim of this study was to investigate whether apolipoprotein B100 of LDL suffers increased damage by glycation, oxidation, and nitration in patients with type 2 diabetes, including patients receiving metformin therapy. RESEARCH DESIGN AND METHODS For this study, 32 type 2 diabetic patients and 21 healthy control subjects were recruited; 13 diabetic patients were receiving metformin therapy (median dose: 1.50 g/day). LDL was isolated from venous plasma by ultracentrifugation, delipidated, digested, and analyzed for protein glycation, oxidation, and nitration adducts by stable isotopic dilution analysis tandem mass spectrometry. RESULTS Advanced glycation end product (AGE) content of apolipoprotein B100 of LDL from type 2 diabetic patients was higher than from healthy subjects: arginine-derived AGE, 15.8 vs. 5.3 mol% (P < 0.001); and lysine-derived AGE, 2.5 vs. 1.5 mol% (P < 0.05). Oxidative damage, mainly methionine sulfoxide residues, was also increased: 2.5 vs. 1.1 molar equivalents (P < 0.001). 3-Nitrotyrosine content was decreased: 0.04 vs. 0.12 mol% (P < 0.05). In diabetic patients receiving metformin therapy, arginine-derived AGE and methionine sulfoxide were lower than in patients not receiving metformin: 19.3 vs. 8.9 mol% (P < 0.01) and 2.9 vs. 1.9 mol% (P < 0.05), respectively; 3-nitrotyrosine content was higher: 0.10 vs. 0.03 mol% (P < 0.05). Fructosyl-lysine residue content correlated positively with fasting plasma glucose. Arginine-derived AGE residue contents were intercorrelated and also correlated positively with methionine sulfoxide. CONCLUSIONS Patients with type 2 diabetes had increased arginine-derived AGEs and oxidative damage in apolipoprotein B100 of LDL. This was lower in patients receiving metformin therapy, which may contribute to decreased oxidative damage, atherogenicity, and cardiovascular disease

    Measurement of the Bottom-Strange Meson Mixing Phase in the Full CDF Data Set

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    We report a measurement of the bottom-strange meson mixing phase \beta_s using the time evolution of B0_s -> J/\psi (->\mu+\mu-) \phi (-> K+ K-) decays in which the quark-flavor content of the bottom-strange meson is identified at production. This measurement uses the full data set of proton-antiproton collisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment at the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity. We report confidence regions in the two-dimensional space of \beta_s and the B0_s decay-width difference \Delta\Gamma_s, and measure \beta_s in [-\pi/2, -1.51] U [-0.06, 0.30] U [1.26, \pi/2] at the 68% confidence level, in agreement with the standard model expectation. Assuming the standard model value of \beta_s, we also determine \Delta\Gamma_s = 0.068 +- 0.026 (stat) +- 0.009 (syst) ps-1 and the mean B0_s lifetime, \tau_s = 1.528 +- 0.019 (stat) +- 0.009 (syst) ps, which are consistent and competitive with determinations by other experiments.Comment: 8 pages, 2 figures, Phys. Rev. Lett 109, 171802 (2012

    Ischemia and reperfusion of the soleus muscle of rats with pentoxifylline

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    BACKGROUND: Reperfusion of the skeletal muscle worsens existing lesions during ischemia, since the production of reactive oxygen species, associated with intense participation of neutrophils, increases the inflammatory reaction that induces tissue changes. OBJECTIVE: To evaluate the morphological and immunohistochemical changes of the skeletal (soleus) muscle of rats submitted to ischemia and reperfusion with pentoxifylline. METHODS: Sixty rats were submitted to ischemia of the pelvic limb for 6 hours induced by clamping the left common iliac artery. After ischemia, group A animals (n = 30) were observed for 4 hours and group B animals (n = 30) for 24 hours. Six animals constituted the sham group. Pentoxifylline was applied only in the reperfusion period A2 (n = 10) and B2 (n = 10), and in ischemia and reperfusion periods in A3 (n = 10) and B3 (n = 10). The soleus muscle was evaluated by histological (fiber disruption, leukocyte infiltrate, necrosis) and immunohistochemical (apoptosis through caspase-3 expression) analysis. The non-parametric tests Kruskal-Wallis and Mann-Whitney (p < 0.05) were applied. RESULTS: The changes were more intense in group B1, with fiber disruption mean scores of 2.16±0.14; neutrophilic infiltrate of 2.05±0.10; and caspase-3 expression in the perivascular area of 4.30±0.79; and less intense in group A3, with means of 0.76±0.16; 0.92±0.10; 0.67±0,15, respectively (p < 0.05). Caspase-3 was more expressive in group B1 in the perivascular area, with mean of 4.30±0.79 when compared with group B1 in the perinuclear area, with mean of 0.91±0.32 (p < 0.05) CONCLUSIONS: The lesions were more intense when observation time was longer after reperfusion, and pentoxifylline attenuated these lesions, above all when used in the beginning of ischemia and reperfusion phases.CONTEXTO: A reperfusão de músculo esquelético piora as lesões já presentes no período de isquemia, pois a produção de espécies reativas de oxigênio, associadas à intensa participação de neutrófilos, amplia a reação inflamatória que induz alterações teciduais. OBJETIVO: Avaliar as alterações morfológicas e imuno-histoquímicas de músculo esquelético (sóleo) de ratos submetidos a isquemia e reperfusão com pentoxifilina. MÉTODOS: Sessenta ratos foram submetidos a isquemia do membro pélvico, por 6 horas, pelo clampeamento da artéria ilíaca comum esquerda. Após isquemia, os animais do grupo A (n = 30) foram observados por 4 horas, e os do grupo B (n = 30), por 24 horas. Seis animais constituíram o grupo simulado. Administrou-se pentoxifilina apenas no período de reperfusão em A2 (n = 10) e B2 (n = 10) e nos períodos de isquemia e reperfusão em A3 (n = 10) e B3 (n = 10). O músculo sóleo foi avaliado por análise histológica (dissociação de fibras, infiltrado leucocitário, necrose) e imuno-histoquímica (apoptose pela expressão da caspase-3). Foram aplicados os testes não-paramétricos de Kruskal-Wallis e Mann-Whitney (p < 0,05). RESULTADOS: As alterações foram mais intensas no grupo B1, com médias de escore da dissociação de fibras musculares de 2,16 ± 0,14, infiltrado neutrofílico de 2,05 ± 0,10 e expressão da caspase-3 na área perivascular de 4,30 ± 0,79; e menos intensas no grupo A3, com respectivas médias de 0,76 ± 0,16, 0,92 ± 0,10 e 0,67 ± 0,15 (p < 0,05). A caspase-3 mostrou-se mais expressiva no grupo B1 na área perivascular, com média de 4,30 ± 0,79, em comparação com o grupo B1 na área perinuclear, com média de 0,91 ± 0,32 (p < 0,05). CONCLUSÕES: As lesões são mais intensas quando o tempo de observação é maior após a reperfusão, e a pentoxifilina atenua essas lesões, sobretudo quando usada no início das fases de isquemia e de reperfusão.SBACVUniversidade Federal de Mato Grosso do Sul Hospital UniversitárioUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de MedicinaUFMSUNIFESP-EPM Departamento de PatologiaUFMS Departamento de Clínica CirúrgicaUFMS Hospital Universitário Comissão de Residência MédicaUNIFESP, EPM, Depto. de PatologiaSciEL

    Robust metabolic transcriptional components in 34,494 patient-derived cancer-related samples and cell lines

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    BACKGROUND: Patient-derived bulk expression profiles of cancers can provide insight into the transcriptional changes that underlie reprogrammed metabolism in cancer. These profiles represent the average expression pattern of all heterogeneous tumor and non-tumor cells present in biopsies of tumor lesions. Hence, subtle transcriptional footprints of metabolic processes can be concealed by other biological processes and experimental artifacts. However, consensus independent component analyses (c-ICA) can capture statistically independent transcriptional footprints of both subtle and more pronounced metabolic processes. METHODS: We performed c-ICA with 34,494 bulk expression profiles of patient-derived tumor biopsies, non-cancer tissues, and cell lines. Gene set enrichment analysis with 608 gene sets that describe metabolic processes was performed to identify the transcriptional components enriched for metabolic processes (mTCs). The activity of these mTCs was determined in all samples to create a metabolic transcriptional landscape. RESULTS: A set of 555 mTCs was identified of which many were robust across different datasets, platforms, and patient-derived tissues and cell lines. We demonstrate how the metabolic transcriptional landscape defined by the activity of these mTCs in samples can be used to explore the associations between the metabolic transcriptome and drug sensitivities, patient outcomes, and the composition of the immune tumor microenvironment. CONCLUSIONS: To facilitate the use of our transcriptional metabolic landscape, we have provided access to all data via a web portal (www.themetaboliclandscapeofcancer.com). We believe this resource will contribute to the formulation of new hypotheses on how to metabolically engage the tumor or its (immune) microenvironment. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s40170-021-00272-7
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