RESUMO
BACKGROUND: Selenoprotein P (SeP), a selenium-rich extracellular glycoprotein, is the primary selenoprotein in the plasma. SeP plays an important role in the maintenance of selenium levels in the peripheral tissues. We developed a new sol particle homogeneous immunoassay (SPIA) for measuring full-length SeP (FL-SeP) levels in the human serum. METHODS: We used colloidal gold particles coated with two types of anti-SeP monoclonal antibodies, one recognizing the N-terminal side domain of SeP and the other recognizing the C-terminal side domain. RESULTS: The assay range was 0.2-9 mg/l, and the linearity was excellent. The within-day and between-day coefficients of variation ranged from 0.73% to 2.24% and 0.45% to 1.11%, respectively. Serum samples (n = 200) were examined using the newly developed assay system (employing a Model 7070 Hitachi automatic clinical analyzer) and the conventional enzyme-linked immunosorbent assay. These two methods were compared using the Passing-Bablok regression analysis; the resulting regression equation and correlation coefficient were y = 0.940x + 0.165 and r = 0.954, respectively. CONCLUSIONS: Our new SPIA assay is a fully automated homogeneous immunoassay that can be used in conjunction with various commercial analyzers. The assay was sensitive, precise, and suitable for clinical measurement of the FL-SeP in the human serum.
Assuntos
Imunoensaio/métodos , Selenoproteína P/sangue , Anticoagulantes/farmacologia , Calibragem , Ensaio de Imunoadsorção Enzimática , Coloide de Ouro , Hemaglutinação , Humanos , Calicreínas/sangue , Limite de Detecção , ProteóliseRESUMO
Group V secretory phospholipase A2 (sPLA2-V) hydrolyzes phosphatidylcholine in low-density lipoprotein (LDL) to increase lysophosphatidylcholine (LPC) content. Because in human umbilical vein endothelial cells (HUVEC), tumor necrosis factor alpha (TNFα)-induced sPLA2-V expression, and LPC content in LDL and monocyte chemoattractant protein-1 mRNA were enhanced by incubation of LDL with TNFα-stimulated HUVEC, we investigated whether an angiotensin II receptor type 1 blocker, telmisartan, or an antioxidant drug, N-acetylcysteine (NAC), suppressed TNFα-induced sPLA2-V expression. Telmisartan or NAC administered before and during TNFα stimulation diminished the increase of sPLA2-V mRNA in HUVEC and reduced TNFα-induced sPLA2-V protein at 3 days after TNFα stimulation. Angiotensin II did not induce sPLA2-V mRNA, and a peroxisome proliferator-activated receptor-γ antagonist, GW3335, did not influence the inhibitory effect of telmisartan on TNFα-induced sPLA2-V mRNA. At 3 days after TNFα stimulation, 30 µM telmisartan or 20 mM NAC administered before and during TNFα stimulation prevented the enhancement of LPC content in LDL and monocyte chemoattractant protein-1 mRNA by LDL incubation with TNFα-stimulated HUVEC. A 2-month treatment with telmisartan in 29 hypertensive type 2 diabetic patients significantly reduced LPC content in circulating LDL. Telmisartan's suppressive effect on TNFα-induced sPLA2-V expression may have beneficial effects in preventing proatherogenic changes of LDL.
Assuntos
Acetilcisteína/farmacologia , Benzimidazóis/farmacologia , Benzoatos/farmacologia , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Hipertensão/tratamento farmacológico , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Antioxidantes/farmacologia , Aterosclerose/prevenção & controle , Quimiocina CCL2/genética , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/fisiopatologia , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Fosfolipases A2 do Grupo V/genética , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Hipertensão/fisiopatologia , Lipoproteínas LDL/efeitos dos fármacos , Lipoproteínas LDL/metabolismo , Lisofosfatidilcolinas/metabolismo , Masculino , Pessoa de Meia-Idade , RNA Mensageiro/metabolismo , Telmisartan , Fator de Necrose Tumoral alfa/farmacologiaRESUMO
The direct alkynylation reaction of 1,3,4-oxadiazoles with alkynyl bromides efficiently proceeds in the presence of a copper catalyst at room temperature to create the corresponding heteroaryl-alkynyl linkage in good yields. This direct coupling provides a rapid and convergent access to oxadiazole core pi-conjugated systems.
RESUMO
The cross-addition of terminal silylacetylenes to gamma-arylated propargyl amines occurs efficiently via C-H cleavage by using either a nickel or rhodium catalyst. Taking advantage of the catalyst-controlled switching of regioselectivity in the reaction, both the 2- and 3-alkynylallylamines are readily accessible from the same starting materials.
RESUMO
We aimed to test the hypothesis that selenoprotein P (SELENOP), a hepatokine involved in the development of both insulin resistance and impaired insulin production in mice, is related to future onset of hyperglycemia in humans. 76 healthy non-pregnant human subjects without diabetes underwent oral glucose tolerance test (OGTT) at baseline and 4-years follow-up. Nine subjects developed either impaired glucose tolerance or type 2 diabetes at follow-up. At baseline, SELENOP concentrations correlated negatively with insulinogenic index, but not with homeostasis model assessment-estimated insulin resistance (HOMA-IR). Multivariate analysis showed that baseline SELENOP predicted fasting plasma glucose at follow-up independently of the other parameters. The receiver operating characteristic (ROC) curve analysis showed that baseline concentrations of serum SELENOP, but not of selenium, were a reliable test to predict future onset of glucose intolerance. In conclusion, elevation of circulating SELENOP, but not of circulating selenium, was positively and independently associated with future onset of glucose intolerance in a general Japanese population.
Assuntos
Hiperglicemia/sangue , Hiperglicemia/diagnóstico , Selênio/sangue , Selenoproteína P/sangue , Glicemia/metabolismo , Jejum/sangue , Feminino , Seguimentos , Humanos , Japão , Masculino , Pessoa de Meia-Idade , PrognósticoRESUMO
Exercise has numerous health-promoting effects in humans; however, individual responsiveness to exercise with regard to endurance or metabolic health differs markedly. This 'exercise resistance' is considered to be congenital, with no evident acquired causative factors. Here we show that the anti-oxidative hepatokine selenoprotein P (SeP) causes exercise resistance through its muscle receptor low-density lipoprotein receptor-related protein 1 (LRP1). SeP-deficient mice showed a 'super-endurance' phenotype after exercise training, as well as enhanced reactive oxygen species (ROS) production, AMP-activated protein kinase (AMPK) phosphorylation and peroxisome proliferative activated receptor γ coactivator (Ppargc)-1α (also known as PGC-1α; encoded by Ppargc1a) expression in skeletal muscle. Supplementation with the anti-oxidant N-acetylcysteine (NAC) reduced ROS production and the endurance capacity in SeP-deficient mice. SeP treatment impaired hydrogen-peroxide-induced adaptations through LRP1 in cultured myotubes and suppressed exercise-induced AMPK phosphorylation and Ppargc1a gene expression in mouse skeletal muscle-effects which were blunted in mice with a muscle-specific LRP1 deficiency. Furthermore, we found that increased amounts of circulating SeP predicted the ineffectiveness of training on endurance capacity in humans. Our study suggests that inhibitors of the SeP-LRP1 axis may function as exercise-enhancing drugs to treat diseases associated with a sedentary lifestyle.
Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Músculo Esquelético/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/genética , Condicionamento Físico Animal , Resistência Física/genética , Espécies Reativas de Oxigênio/metabolismo , Receptores de LDL/metabolismo , Selenoproteína P/genética , Proteínas Supressoras de Tumor/metabolismo , Acetilcisteína/farmacologia , Animais , Antioxidantes/farmacologia , Exercício Físico , Humanos , Proteína-1 Relacionada a Receptor de Lipoproteína de Baixa Densidade , Camundongos , Camundongos Knockout , Fibras Musculares Esqueléticas/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Fosforilação , Condicionamento Físico Humano , Resistência Física/efeitos dos fármacos , Selenoproteína P/metabolismo , Regulação para CimaRESUMO
BACKGROUND: We introduce a new assay method to measure the concentration of fecal calprotectin that can be applied in exclusive analyzers. The assay method uses gold colloidal reagents. In addition, we report performance evaluation results for the new method and the results of comparisons with enzyme-linked immunosorbent assay (ELISA) methods. METHODS: We evaluated the new method by linearity tests and within-run tests. In addition, we collected specimens from patients with a definitive diagnosis of inflammatory bowel disease (n=566) and examined them using the new method. The results were compared with those from 2 commercially available ELISA kits. RESULTS: In the linearity tests, the correlation coefficients between the measured values and the theoretical values were 0.9980-0.9990. In the within-run tests, the CVs were 3.4-4.3%. The correlation coefficients for our method and the 2 ELISA kits showed high correlations of 0.945 and 0.942. CONCLUSIONS: Our assay is capable of measuring calprotectin concentrations in feces, and has a similar performance to commercially available ELISA methods. Our method is an automated assay system, which is an easier, cheaper, and quicker measurement method than conventional ELISA kits. Therefore, our assay is suitable for daily clinical use.
Assuntos
Ensaio de Imunoadsorção Enzimática/métodos , Fezes/química , Doenças Inflamatórias Intestinais/diagnóstico , Complexo Antígeno L1 Leucocitário/análise , Adulto , Calibragem , Feminino , Humanos , Limite de Detecção , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Fatores de TempoRESUMO
Continuous tuning of the backbone conformation and interchain distance of a π-conjugated polymer is an essential prerequisite to unveil the inherent electrical and optical features of organic electronics. To this end, applying pressure in a hydrostatic medium or diamond anvil cell is a facile approach without the need for side-chain synthetic engineering. We report the development of high-pressure, time-resolved microwave conductivity (HP-TRMC) and evaluation of transient photoconductivity in the regioregular poly(3-hexylthiophene) (P3HT) film and its bulk heterojunction blend with methanofullerene (PCBM). X-ray diffraction experiments under high pressure were performed to detail the pressure dependence of π-stacking and interlamellar distances in P3HT crystallites and PCBM aggregates. The HP-TRMC results were further correlated with high-pressure Raman spectroscopy and density functional theory calculation. The increased HP-TRMC conductivity of P3HT under pressure was found to be relevant to the planarity of the backbone conformation and intramolecular hole mobility. The effects of pressure on the backbone planarity are estimated to be â¼0.3 kJ mol(-1) based on the compressibility derived from the X-ray diffraction under high pressure, suggesting the high enough energy to cause modulation of the planarity in terms of the Landau-de Gennes free energy of isolated P3HT chains as 0.23 kJ mol(-1). In contrast, the P3HT:PCBM blend showed a simple decrease in photoconductivity irrespective of the identical compressive behavior of P3HT. A mechanistic insight into the interplay of intra- and intermolecular mobilities is a key to tailoring the dynamic π-figuration associated with electrical properties, which may lead to the use of HP-TRMC for exploring divergent π-conjugated materials at the desired molecular arrangement and conformation.
RESUMO
A silacyclophane molecule with two disilanyl pillars and two oligoarylene units was synthesized. The molecule was packed in a single crystal with a new motif interfusing π-stack and herringbone packing structures. The hole transporting ability of the solid was revealed by using the flash-photolysis time-resolved microwave conductivity method. The molecular structure, albeit a singly-bonded arylene macrocycle, was rigidified by the unique packing array, which favorably contributed to the hole transporting ability of the solid via the small reorganization energy through the charge transport.
RESUMO
Curved π-conjugated molecules with closed and three-dimensional (3D) structures, such as fullerenes and carbon nanotubes, have been the subject of intensive research due to their potential applications in molecular electronics. However, basic molecular skeletons of 3D molecules are limited because of the lack of a rational and selective synthetic method by organic synthesis. Here we report the synthesis of a 3D π-conjugated molecule based on the platinum-mediated assembly of four molecules of a stannylated trisubstituted benzene derivative forming a hexanuclear platinum complex with an octahedral shape, from which reductive elimination of platinum gave the target molecule. As many supramolecular transition metal-ligand complexes with 3D cages and polyhedral structures have been synthesized by self-assembly of ligands and metals, the current assembly/reductive elimination strategy could provide a variety of new 3D π-conjugated molecules with different structures and topologies, which are challenging to obtain using conventional synthetic methods.
RESUMO
BACKGROUND: Sphingomyelin (SM) is an important choline group-containing phospholipid and is considered to be an independent risk factor for coronary heart disease. METHODS: We have developed a specific enzymatic assay for SM measurement with rapid and automatable performances by using two-reagent system involving sphingomyelinase. We performed within-run and between-run precision, linearity test, detection limit, recovery test and interference to validate this assay. Then, we measured the serum SM concentration in 194 healthy subjects and 141 consecutive patients undergoing coronary angiography. RESULTS: The within-run and between-run coefficients of variation for SM concentrations were 1.1-1.3% and 1.0-1.2%, respectively. Quantitative measurements to a lower limit of 30 µmol/L were shown to be possible. The recoveries of the exogenously added SM to the control samples were 98.7%-101.5%. No effect was observed after the addition of some interference materials. The mean ± SD of the serum SM concentration in the 194 healthy subjects was 553.3 ± 100.1 µmol/L. We found that the SM concentration was significantly higher among an acute coronary syndrome subjects than among the healthy subjects (P<0.01) and that the serum SM concentrations were significantly correlated with the serum magnesium concentration. CONCLUSIONS: We have developed a rapid and automatable enzymatic assay for SM that enables the automatic measurement of choline-containing phospholipids. This assay may be useful for various types of biochemical and clinical research.
Assuntos
Síndrome Coronariana Aguda/sangue , Angina Estável/sangue , Doença da Artéria Coronariana/sangue , Ensaios Enzimáticos/normas , Esfingomielinas/sangue , 1,2-Dipalmitoilfosfatidilcolina/sangue , Análise de Variância , Calibragem , Estudos de Casos e Controles , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Feminino , Humanos , Limite de Detecção , Lisofosfatidilcolinas/sangue , Magnésio/sangue , Masculino , Padrões de ReferênciaRESUMO
Pt/CeO(2)-ZrO(2)-Bi(2)O(3)/gamma-Al(2)O(3) (Pt/CZB/Al(2)O(3)) catalysts for the catalytic combustion of toluene, which is one of the volatile organic compounds (VOCs), were prepared by the wet impregnation method in the presence of polyvinyl pyrrolidone (PVP). X-ray powder diffraction, transmission electron microscopy, and BET specific surface area measurement using N(2) adsorption have been used to characterize the catalysts. The catalytic test was conducted from room temperature in a flow of 900 ppm of toluene in air and gas hourly space velocity (GHSV) of 8000 h(-1). The catalytic activity was evaluated in terms of C(7)H(8) conversion and the gas composition after the reaction was analyzed using two gas chromatographs with a flame ionization detector (FID) and a thermal conductivity detector (TCD). The Pt/CZB/Al(2)O(3) catalysts are specific for the total toluene oxidation and CO and any toluene-derivative compounds were not detected as by-products. The specific surface area of the catalysts was increased by the addition of PVP in the preparation process. By the optimization of the amount of platinum, complete oxidation of toluene was realized at a temperature as low as 120 degrees C on a 7 wt%Pt/16 wt%Ce(0.64)Zr(0.15)Bi(0.21)O(1.895)/gamma-Al(2)O(3) catalyst.
Assuntos
Poluentes Atmosféricos/química , Pirrolidinonas/química , Tolueno/química , Compostos Orgânicos Voláteis/química , Óxido de Alumínio , Bismuto , Compostos de Boro , Catálise , Cério , Incineração , Oxirredução , Platina , Polivinil , ZircônioRESUMO
The direct C-H alkynylation of azoles with terminal alkynes proceeds efficiently under a nickel/O(2) catalytic system. On the other hand, a copper/air catalyst enables the coupling of polyfluoroarenes with terminal alkynes. These catalyses provide new accesses to arylacetylenes through the formal direct Sonogashira coupling.
Assuntos
Alcinos/química , Azóis/química , Cobre/química , Fluorbenzenos/química , Níquel/química , Oxigênio/química , Acetileno/análogos & derivados , Acetileno/síntese química , Acetileno/química , Atmosfera/química , Catálise , Estrutura Molecular , EstereoisomerismoRESUMO
The direct C-H alkynylation of azoles with alkynyl bromides proceeds efficiently in the presence of a nickel-based catalyst system. The reaction enables the introduction of various alkynyl groups bearing aryl, alkenyl, alkyl, and silyl substituents to the azole cores. In some cases, addition of a catalytic amount of CuI is observed to accelerate the direct coupling dramatically.
RESUMO
AIMS: We studied the relations of lysophosphatidylcholine (lyso-PC) in LDL with serum lipoprotein-associated phospholipase A(2) (Lp-PLA(2)), paraoxonase and homocysteine thiolactonase (HTLase) activities in patients with type 2 diabetes mellitus. METHODS: Lyso-PC was measured by electrospray ionization-liquid chromatography/mass spectrometry. Paraoxonase and HTLase activities were measured with paraoxon and gamma-thiobutyrolactone as substrates, respectively. RESULTS: Serum HTLase and paraoxonase activities were significantly suppressed in diabetic patients (n=96) compared with control (n=25), whereas serum Lp-PLA(2) did not differ in control and diabetic patients. Lyso-PC contents in LDL correlated with serum Lp-PLA(2) activity positively and with serum HTLase activity negatively. Stepwise regression analysis revealed that serum Lp-PLA(2) and HTLase activities independently contributed to lyso-PC contents in LDL. In patients with diabetic nephropathy, lyso-PC contents in LDL were increased with reduced serum HTLase and paraoxonase activities compared with control, while serum Lp-PLA(2) activity did not differ. On the other hand, 3-month treatment with simvastatin reduced both lyso-PC contents in LDL and serum Lp-PLA(2) activity in hypercholesterolemic diabetic patients, while serum HTLase or paraoxonase activities did not change. CONCLUSIONS: Increased lyso-PC contents in LDL were associated with the suppressed HTLase activity, and serum Lp-PLA(2) and HTLase activities may be related to lyso-PC in type 2 diabetic patients.