994 resultados para Dc Plasma
Resumo:
The aim of this study was to assess the alterations in plasma, liver, and meat oxidative stability and R-tocopherol content when moderately oxidized sunflower oils were added to feeds and when feeds were supplemented with R-tocopheryl acetate (100 mg/kg) and Zn (200 mg/kg). The effects of cooking the meat and its subsequent refrigeration were also studied. When the content of primary oxidation compounds of the oil was high, rabbit plasma, liver, and meat R-tocopherol content was reduced and meat susceptibility to oxidation increased. The addition of oil with a high content of secondary oxidation compounds (oil heated at 140 'C, 31 h) to feed also led to an increase in meat susceptibi- lity to oxidation, although it presented an R-tocopherol content similar to that of nonheated oil. Feed supplementation with R-tocopheryl acetate increased tissue R-tocopherol content and improved the oxidative stability of liver and meat. However, in the latter, it was less effective when oil heated at 55 'C was added.
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Activating mutations in the K-Ras small GTPase are extensively found in human tumors. Although these mutations induce the generation of a constitutively GTP-loaded, active form of K-Ras, phosphorylation at Ser181 within the C-terminal hypervariable region can modulate oncogenic K-Ras function without affecting the in vitro affinity for its effector Raf-1. In striking contrast, K-Ras phosphorylated at Ser181 shows increased interaction in cells with the active form of Raf-1 and with p110α, the catalytic subunit of PI 3-kinase. Because the majority of phosphorylated K-Ras is located at the plasma membrane, different localization within this membrane according to the phosphorylation status was explored. Density-gradient fractionation of the plasma membrane in the absence of detergents showed segregation of K-Ras mutants that carry a phosphomimetic or unphosphorylatable serine residue (S181D or S181A, respectively). Moreover, statistical analysis of immunoelectron microscopy showed that both phosphorylation mutants form distinct nanoclusters that do not overlap. Finally, induction of oncogenic K-Ras phosphorylation - by activation of protein kinase C (PKC) - increased its co-clustering with the phosphomimetic K-Ras mutant, whereas (when PKC is inhibited) non-phosphorylated oncogenic K-Ras clusters with the non-phosphorylatable K-Ras mutant. Most interestingly, PI 3-kinase (p110α) was found in phosphorylated K-Ras nanoclusters but not in non-phosphorylated K-Ras nanoclusters. In conclusion, our data provide - for the first time - evidence that PKC-dependent phosphorylation of oncogenic K-Ras induced its segregation in spatially distinct nanoclusters at the plasma membrane that, in turn, favor activation of Raf-1 and PI 3-kinase.
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BACKGROUND AND AIMS: Formerly obese patients having undergone Roux-en-Y gastric bypass (RYGB) display both an accelerated digestion and absorption of carbohydrate and an increased plasma glucose clearance rate after meal ingestion. How RYGB effects postprandial kinetics of dietary lipids has yet not been investigated. METHODS: Plasma triglyceride (TG), apoB48, total apoB, bile acids (BA), fibroblast growth factor 19 (FGF19), and cholecystokinin (CCK) were measured in post-absorptive conditions and over 4-h following the ingestion of a mixed test meal in a cross-sectional, pilot study involving 11 formerly obese female patients 33.8 ± 16.4 months after RYGB surgery and in 11 weight- and age-matched female control participants. RESULTS: Compared to controls, RYGB patients had faster (254 ± 14 vs. 327 ± 7 min, p < 0.05) and lower (0.14 ± 0.04 vs. 0.35 ± 0.07 mM, p < 0.05) peak TG responses, but their peak apoB48 responses tended to be higher (2692 ± 336 vs. 1841 ± 228 ng/ml, p = 0.09). Their postprandial total BA concentrations were significantly increased and peaked earlier after meal ingestion than in controls. Their FGF19 and CCK concentrations also peaked earlier and to a higher value. CONCLUSIONS: The early postprandial apoB48 and BA responses indicate that RYGB accelerated the rate of dietary lipid absorption. The lower postprandial peak TG strongly suggests that the RYGB simultaneously increased the clearance of TG-rich lipoproteins. CLINICAL TRIAL REGISTRATION: NCT01891591.
Resumo:
En otoño de 1984 tuvimos la ocasión de recolectar este orófito europeo, con fruto maduro, en la cumbre del macizo calcáreo de la 'Mare de Deu del Mont', próximo a la población de Besalú (Prepirineos orientales). Vive en los rellanos herbosos inclinados, fisuras y oquedades de la cumbre, muy localizado, en pastos mesoxerófilos del Festucion gautieri. Un inventario tomado en el lugar muestra la siguiente composición florística (exp. N, incl. 60°, cobert. 100%): Festuca gautieri 5.5, Peucedanum schottii 2.3, Veronica austriaca subsp. vahlii 1.1, Avenula mirandana 1.1, Cruciata glabra 1.1, Phyteuma orbiculare 1.1, Seseli montanum 1.1, Dianthus seguieri subsp. gautieri 1.1, Galium pinetorum + , Vicia sepium +, Campanula rotundifolia +, Moehringia muscosa +.1, Allium senescens +, Teucrium chamaedrys + , Asperula cynanchica +, Dactylis glomerata + , Dianthus monspeliacus +, Sedum reflexum +, Vincetoxicum hirundinaria subsp. intermedium +.
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The effects of the addition of heated oils to feeds (3%, w/w) and the dietary supplementation with a-tocopheryl acetate (TA; 100 mg/kg) and Zn (200 mg/kg) on rabbit tissue fatty acid (FA) composition and on the Zn, Cu, Fe and Se content in meat were assessed. Heating unrefined sunflower oil (SO) at 558C for 245 h increased its content in primary oxidation products and reduced its a-tocopherol content. However, this did not significantly affect tissue FA composition. Heating SO at 1408C for 31 h increased its content in secondary oxidation products and in some FA isomers asc9,t11-CLA and di-trans CLA. This led to increases in di-trans CLA in liver and in t9,c12-18:2 in meat. The c9,t11-CLA was the most incorporated CLA isomer in tissues. The dietary supplementation with a-TA did not affect the FA composition of plasma, liver or meat. The cooking of vacuum-packed rabbit meat at 788C for 5 min reduced significantly but slightly its polyunsaturated FA content. The dietary supplementation with Zn did not modify the content of Zn, Fe or Se in meat, but it reduced its Cu content. On the other hand, it increased the content of some FAs in meat when SO heated at 1408C for 31 h was added to feeds.
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Proteinuria and hyperphosphatemia are cardiovascular risk factors independent of GFR. We hypothesized that proteinuria induces relative phosphate retention via increased proximal tubule phosphate reabsorption. To test the clinical relevance of this hypothesis, we studied phosphate handling in nephrotic children and patients with CKD. Plasma fibroblast growth factor 23 (FGF-23) concentration, plasma phosphate concentration, and tubular reabsorption of phosphate increased during the proteinuric phase compared with the remission phase in nephrotic children. Cross-sectional analysis of a cohort of 1738 patients with CKD showed that albuminuria≥300 mg/24 hours is predictive of higher phosphate levels, independent of GFR and other confounding factors. Albuminuric patients also displayed higher plasma FGF-23 and parathyroid hormone levels. To understand the molecular mechanisms underlying these observations, we induced glomerular proteinuria in two animal models. Rats with puromycin-aminonucleoside-induced nephrotic proteinuria displayed higher renal protein expression of the sodium-phosphate co-transporter NaPi-IIa, lower renal Klotho protein expression, and decreased phosphorylation of FGF receptor substrate 2α, a major FGF-23 receptor substrate. These findings were confirmed in transgenic mice that develop nephrotic-range proteinuria resulting from podocyte depletion. In vitro, albumin did not directly alter phosphate uptake in cultured proximal tubule OK cells. In conclusion, we show that proteinuria increases plasma phosphate concentration independent of GFR. This effect relies on increased proximal tubule NaPi-IIa expression secondary to decreased FGF-23 biologic activity. Proteinuria induces elevation of both plasma phosphate and FGF-23 concentrations, potentially contributing to cardiovascular disease.
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BACKGROUND: Lymphedema is an underdiagnosed pathology which in industrialized countries mainly affects cancer patients that underwent lymph node dissection and/or radiation. Currently no effective therapy is available so that patients' life quality is compromised by swellings of the concerned body region. This unfortunate condition is associated with body imbalance and subsequent osteochondral deformations and impaired function as well as with an increased risk of potentially life threatening soft tissue infections. METHODS: The effects of PRP and ASC on angiogenesis (anti-CD31 staining), microcirculation (Laser Doppler Imaging), lymphangiogenesis (anti-LYVE1 staining), microvascular architecture (corrosion casting) and wound healing (digital planimetry) are studied in a murine tail lymphedema model. RESULTS: Wounds treated by PRP and ASC healed faster and showed a significantly increased epithelialization mainly from the proximal wound margin. The application of PRP induced a significantly increased lymphangiogenesis while the application of ASC did not induce any significant change in this regard. CONCLUSIONS: PRP and ASC affect lymphangiogenesis and lymphedema development and might represent a promising approach to improve regeneration of lymphatic vessels, restore disrupted lymphatic circulation and treat or prevent lymphedema alone or in combination with currently available lymphedema therapies.
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Con motivo de los estudios biosistemáticos realizados en el marco de una tesis doctoral [J. SIMON, Estudis Biosistics en especies Euphorbia de la subsecció Galarrhaei en la mediterránea occidental, inédita, 1993] sobre las especies no nanofanerófitas y con cápsulas verrugosas de Euphorbia subsect. Galarrhaei (Boiss.) Pax, detectamos dentro del grupo de Euphorbia flavicoma DC. algunas poblaciones de difícil adscripción. El estudio de más de 700 pliegos de esta especie, así como el análisis multivariante, realizado sobre un total de 88 caracteres, nos obliga a proponer una nueva subespecie definida ante todo por el tipo de indumento de tallos y hojas, formado por tricomas largos y patentes -muy diferentes de los cortos y crespos que se presentan en el resto de las subespecies-, y que además recubre ambas caras foliares -en el resto de las subespecies los tricomas tan solo se encuentran en el margen foliar-. Como caracteres complementarios, se pueden destacar la disposición claramente refleja de las hojas y su aspecto ligeramente seríceo.
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En este trabajo se estudia el sistema reproductivo de Diplotaxis erucoides (L.) DC. (Brassicaceae), una especie arvense ampliamente distribuida en los cultivos y los márgenes de caminos de la región mediterránea. Mediante polinizaciones manuales con polen procedente de la propia flor (autogamia), de flores del mismo individuo (geitonogamia) y de flores de individuos de otras poblaciones (alogamia) se analiza el efecto de los diferentes tratamientos de polinización sobre la producción de frutos y semillas. Los resultados obtenidos muestran que Diplotaxis erucoides es una especie con capacidad para autopolinizarse. Hay diferencias significativas en la fertilidad y en el número de semillas por fruto entre los tratamientos que generan alogamia y los que originan autogamia. Dentro de los tratamientos con autogamia, la fertilidad disminuye progresivamente en el paso de geitonogamia a autogamia por autopolinización inducida y a autogamia por autopolinización espontánea.
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Mantle cell lymphoma is a mature lymphoid neoplasm characterized by the t(11;14)(q13;q32) and cyclin D1 overexpression. SOX11 is a transcription factor commonly overexpressed in these tumors but absent in most other mature B-cell lymphomas whose function is not well understood. Experimental studies have shown that silencing of SOX11 in mantle cell lymphoma cells promotes the shift from a mature B cell into an early plasmacytic differentiation phenotype, suggesting that SOX11 may contribute to tumor development by blocking the B-cell differentiation program. The relationship between SOX11 expression and terminal B-cell differentiation in primary mantle cell lymphoma and its relationship to the plasmacytic differentiation observed in occasional cases is not known. In this study we have investigated the terminal B-cell differentiation phenotype in 60 mantle cell lymphomas, 41 SOX11-positive and 19 SOX11-negative. Monotypic plasma cells and lymphoid cells with plasmacytic differentiation expressing cyclin D1 were observed in 7 (37%) SOX11-negative but in none of 41 SOX11-positive mantle cell lymphomas (P<0.001). Intense cytoplasmic expression of a restricted immunoglobulin light chain was significantly more frequent in SOX11-negative than -positive tumors (58 vs 13%) (P=0.001). Similarly, BLIMP1 and XBP1 expression was also significantly more frequent in SOX11-negative than in -positive cases (83 vs 34% and 75 vs 11%, respectively) (P=0.001). However, no differences in the expression of IRF4/MUM1 were observed among these subtypes of mantle cell lymphoma. In conclusion, these results indicate that SOX11-negative mantle cell lymphoma may be a particular subtype of this tumor characterized by more frequent morphological and immunophenotypic terminal B-cell differentiation features that may be facilitated by the absence of SOX11 transcription factor.
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Adherence to aMediterranean diet (MD) is associated with a reduced risk of coronary heart disease. However, themolecular mechanisms involved are not fully understood. The aim of this studywas to compare the effects of 2MD with those of a lowfat- diet (LFD) on circulating inflammatory biomarkers related to atherogenesis. A total of 516 participants included in the PreventionwithMediterraneanDiet Studywere randomized into 3 intervention groups [MD supplementedwith virgin olive oil (MD-VOO); MD supplemented with mixed nuts (MD-Nuts); and LFD]. At baseline and after 1 y, participants completed FFQ and adherence to MD questionnaires, and plasma concentrations of inflammatory markers including intercellular adhesion molecule-1(ICAM-1), IL-6, and 2 TNF receptors (TNFR60 and TNFR80) were measured by ELISA. At 1 y, the MD groups had lower plasma concentrations of IL-6, TNFR60, and TNFR80 (P , 0.05), whereas ICAM-1, TNFR60, and TNFR80 concentrations increased in the LFD group (P , 0.002). Due to between-group differences, participants in the 2 MD groups had lower plasma concentrations of ICAM-1, IL-6, TNFR60, and TNFR80 compared to those in the LFD group (P # 0.028). When participants were categorized in tertiles of 1-y changes in the consumption of selected foods, those in the highest tertile of virgin olive oil (VOO) and vegetable consumption had a lower plasma TNFR60 concentration compared with those in tertile 1 (P,0.02).Moreover, the only changes in consumption thatwere associated with 1-y changes in the geometricmean TNFR60 concentrations were those of VOO and vegetables (P = 0.01). This study suggests that a MD reduces TNFR concentrations in patients at high cardiovascular risk.
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Efavirenz (EFV) is principally metabolized by CYP2B6 to 8-hydroxy-efavirenz (8OH-EFV) and to a lesser extent by CYP2A6 to 7-hydroxy-efavirenz (7OH-EFV). So far, most metabolite profile analyses have been restricted to 8OH-EFV, 7OH-EFV, and EFV-N-glucuronide, even though these metabolites represent a minor percentage of EFV metabolites present in vivo. We have performed a quantitative phase I and II metabolite profile analysis by tandem mass spectrometry of plasma, cerebrospinal fluid (CSF), and urine samples in 71 human immunodeficiency virus patients taking efavirenz, prior to and after enzymatic (glucuronidase and sulfatase) hydrolysis. We have shown that phase II metabolites constitute the major part of the known circulating efavirenz species in humans. The 8OH-EFV-glucuronide (gln) and 8OH-EFV-sulfate (identified for the first time) in humans were found to be 64- and 7-fold higher than the parent 8OH-EFV, respectively. In individuals (n = 67) genotyped for CYP2B6, 2A6, and CYP3A metabolic pathways, 8OH-EFV/EFV ratios in plasma were an index of CYP2B6 phenotypic activity (P < 0.0001), which was also reflected by phase II metabolites 8OH-EFV-glucuronide/EFV and 8OH-EFV-sulfate/EFV ratios. Neither EFV nor 8OH-EFV, nor any other considered metabolites in plasma were associated with an increased risk of central nervous system (CNS) toxicity. In CSF, 8OH-EFV levels were not influenced by CYP2B6 genotypes and did not predict CNS toxicity. The phase II metabolites 8OH-EFV-gln, 8OH-EFV-sulfate, and 7OH-EFV-gln were present in CSF at 2- to 9-fold higher concentrations than 8OH-EFV. The potential contribution of known and previously unreported EFV metabolites in CSF to the neuropsychological effects of efavirenz needs to be further examined in larger cohort studies.
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Renal denervation can reduce blood pressure in patients with uncontrolled hypertension. The adherence to prescribed antihypertensive medication following renal denervation is unknown. This study investigated adherence to prescribed antihypertensive treatment by liquid chromatography-high resolution tandem mass spectrometry in plasma and urine at baseline and 6 months after renal denervation in 100 patients with resistant hypertension, defined as baseline office systolic blood pressure ≥140 mmHg despite treatment with ≥3 antihypertensive agents. At baseline, complete adherence to all prescribed antihypertensive agents was observed in 52 patients, 46 patients were partially adherent, and two patients were completely non-adherent. Baseline office blood pressure was 167/88 ± 19/16 mmHg with a corresponding 24-h blood pressure of 154/86 ± 15/13 mmHg. Renal denervation significantly reduced office and ambulatory blood pressure at 6-month follow-up by 15/5 mmHg (p < 0.001/p < 0.001) and 8/4 mmHg (p < 0.001/p = 0.001), respectively. Mean adherence to prescribed treatment was significantly reduced from 85.0 % at baseline to 80.7 %, 6 months after renal denervation (p = 0.005). The blood pressure decrease was not explained by improvements in adherence following the procedure. Patients not responding to treatment significantly reduced their drug intake following the procedure. Adherence was highest for angiotensin-converting enzyme inhibitors/angiotensin receptor blockers and beta blockers (>90 %) and lowest for vasodilators (21 %). In conclusion, renal denervation can reduce office and ambulatory blood pressure in patients with resistant hypertension despite a significant reduction in adherence to antihypertensive treatment after 6 months.