993 resultados para Régnier, L.-P.


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We report here genome sequences and comparative analyses of three closely related parasitoid wasps: Nasonia vitripennis, N. giraulti, and N. longicornis. Parasitoids are important regulators of arthropod populations, including major agricultural pests and disease vectors, and Nasonia is an emerging genetic model, particularly for evolutionary and developmental genetics. Key findings include the identification of a functional DNA methylation tool kit; hymenopteran-specific genes including diverse venoms; lateral gene transfers among Pox viruses, Wolbachia, and Nasonia; and the rapid evolution of genes involved in nuclear-mitochondrial interactions that are implicated in speciation. Newly developed genome resources advance Nasonia for genetic research, accelerate mapping and cloning of quantitative trait loci, and will ultimately provide tools and knowledge for further increasing the utility of parasitoids as pest insect-control agents.

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Proteins stored in insect hemolymph may serve (is a source of amino acids and energy for metabolism, and development. The expression of the main storage proteins was assessed in bacterial-challenged honey bees using real-time (RT)-PCH and Western blot.. After ensuring that. the immune system had, been activated by measuring the ensuing expression (, the innate immune response genes, defensin-1 (def-1) and prophenoloxidase (pro PO), we verified the expression of four genes encoding storage proteins. The levels of vitellogenin (vg) mRNA and of the respective protein. were significantly lowered in bees injected with bacteria or water only (injury). An equivalent response was observed in orally-infected bees. The levels of apolipophorin II/I (apoLP-II/I) and hexamerin (hex 70a) mRNAs did not significantly change, but levels of Hex 70a protein subunit showed a substantial decay after bacterial challenge or injury. Infection also caused a strong reduction in the levels of apoLP-III transcripts. Our findings are consistent with a down-regulation, of the express and accumulation of storage proteins as a consequence of activation of the immune system, suggesting that this phenomenon. represents a strategy to redirect resources to combat injury or infection. (C) 2009 Wiley Periodicals, Inc.

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The electrocatalytic activity of Pt and RuO(2) mixed electrodes of different compositions towards methanol oxidation was investigated. The catalysts were prepared by thermal decomposition of polymeric precursors and characterized by energy dispersive X-ray, scanning electronic microscopy, X-ray diffraction and cyclic voltammetry. This preparation method allowed obtaining uniform films with controlled stoichiometry and high surface area. Cyclic voltammetry experiments in the presence of methanol showed that mixed electrodes decreased the potential peak of methanol oxidation by approximately 100 mV (RHE) when compared to the electrode containing only Pt. In addition, voltammetric experiments indicated that the Pt(0.6)Ru(0.4)O(y) electrode led to higher oxidation current densities at lower potentials. Chronoamperometry experiments confirmed the contribution of RuO(2) to the catalytic activity as well as the better performance of the Pt(0.6)Ru(0.4)O(y) electrode composition. Formic acid and CO(2) were identified as being the reaction products formed in the electrolysis performed at 400 and 600 mV. The relative formation of CO(2) was favored in the electrolysis performed at 400 mV (RHE) with the Pt(0.6)Ru(0.4)O(y) electrode. The presence of RuO(2) in Pt-Ru-based electrodes is important for improving the catalytic activity towards methanol electrooxidation. Moreover, the thermal decomposition of polymeric precursors seems to be a promising route for the production of catalysts applicable to DMFC. (C) 2009 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.

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A sensitive and automated method is described for determination of rifampicin in plasma samples for therapeutic drug monitoring by in-tube solid-phase microextraction coupled with liquid chromatography (in-tube SPME/LC). Important factors in the optimization of in-tube SPME are discussed, such as coating type, sample pH, sample draw/eject volume, number of draw/eject cycles, and draw/eject flow rate. Analyte pre-concentrated in the polyethylene glycol phase was directly transferred to the liquid chromatographic column by percolation of the mobile phase, without carryover. The method was linear over the 0.1-100 mu g/mL range, with a linear coefficient value (r(2)) of 0.998. The inter-assay precision presented coefficient of variation <= 1.7%. The effectiveness and practicability of the proposed method are proven by analysis of plasma samples from ageing patients undergoing therapy with rifampicin. (C) 2011 Elsevier B.V. All rights reserved.

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Objective To assess how well B-type natriuretic peptide (BNP) predicts prognosis in patients with heart failure. Design Systematic review of studies assessing BNP for prognosis m patients with heart failure or asymptomatic patients. Data sources Electronic searches of Medline and Embase from January 1994 to March 2004 and reference lists of included studies. Study selection and data extraction We included all studies that estimated the relation between BNP measurement and the risk of death, cardiac death, sudden death, or cardiovascular event in patients with heart failure or asymptomatic patients, including initial values and changes in values in response to treatment. Multivariable models that included both BNP and left ventricular ejection fraction as predictors were used to compare the prognostic value of each variable. Two reviewers independently selected studies and extracted data. Data synthesis 19 studies used BNP to estimate the relative risk of death or cardiovascular events in heart failure patients and five studies in asymptomatic patients. In heart failure patients, each 100 pg/ml increase was associated with a 35% increase in the relative risk of death. BNP was used in 35 multivariable models of prognosis. In nine of the models, it was the only variable to reach significance-that is, other variables contained no prognostic information beyond that of BNP. Even allowing for the scale of the variables, it seems to be a strong indicator of risk. Conclusion Although systematic reviews of prognostic studies have inherent difficulties, including die possibility of publication bias, the results of the studies in this review show that BNP is a strong prognostic indicator for both asymptomatic patients mid for patients with heart failure at all stages of disease.

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A long-standing challenge of content-based image retrieval (CBIR) systems is the definition of a suitable distance function to measure the similarity between images in an application context which complies with the human perception of similarity. In this paper, we present a new family of distance functions, called attribute concurrence influence distances (AID), which serve to retrieve images by similarity. These distances address an important aspect of the psychophysical notion of similarity in comparisons of images: the effect of concurrent variations in the values of different image attributes. The AID functions allow for comparisons of feature vectors by choosing one of two parameterized expressions: one targeting weak attribute concurrence influence and the other for strong concurrence influence. This paper presents the mathematical definition and implementation of the AID family for a two-dimensional feature space and its extension to any dimension. The composition of the AID family with L (p) distance family is considered to propose a procedure to determine the best distance for a specific application. Experimental results involving several sets of medical images demonstrate that, taking as reference the perception of the specialist in the field (radiologist), the AID functions perform better than the general distance functions commonly used in CBIR.

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P>Antibody-mediated rejection (AMR) requires specific diagnostic tools and treatment and is associated with lower graft survival. We prospectively screened C4d in pancreas (n = 35, in 27 patients) and kidney (n = 33, in 21 patients) for cause biopsies. Serum amylase and lipase, amylasuria, fasting blood glucose (FBG) and 2-h capillary glucose (CG) were also analysed. We found that 27.3% of kidney biopsies and 43% of pancreatic biopsies showed C4d staining (66.7% and 53.3% diffuse in peritubular and interacinar capillaries respectively). Isolated exocrine dysfunction was the main indication for pancreas biopsy (54.3%) and was followed by both exocrine and endocrine dysfunctions (37.1%) and isolated endocrine dysfunction (8.6%). Laboratorial parameters were comparable between T-cell mediated rejection and AMR: amylase 151.5 vs. 149 U/l (P = 0.075), lipase 1120 vs. 1288.5 U/l (P = 0.83), amylasuria variation 46.5 vs. 61% (P = 0.97), FBG 69 vs. 97 mg/dl (P = 0.20) and 2-h CG maximum 149.5 vs. 197.5 mg/dl (P = 0.49) respectively. Amylasuria values after treatment correlated with pancreas allograft loss (P = 0.015). These data suggest that C4d staining should be routinely investigated when pancreas allograft dysfunction is present because of its high detection rate in cases of rejection.

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High nutritional levels of iodine may induce a higher prevalence of autoimmune thyroiditis,hypothyroidism, goiter, as well as hyperthyroidism, mostly in the elderly. This study assessed thyroid volume and ultrasonographic abnormalities as well as urinary iodine excretion (UIE) in 964 schoolchildren living in an iodine-sufficient area in southern Brazil. Thyroid volume correlated with age and body surface area in boys and girls. In 76.8% of the children, UIE was above 300 mu g/l, with higher levels among boys compared to girls (484.2 mu g/l vs 435.3 mu g/l, p <0.001). Thyroid abnormalities detected by ultrasonography included hemiagenesis (0.5%), nodules (0.2%), cysts (0.7%), and hypoechogenicity (11.7%). Goiter was present in 1.9% of the children. Hypoechogenicity, a relevant marker of autoimmune thyroiditis, was the most common abnormality found in our study, and this may be linked to excessive iodine intake.

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Background and Aims: Calcium-containing phosphate binders have been shown to increase the progression of vascular calcification in hemodialysis patients. This is a prospective study that compares the effects of calcium acetate and sevelamer on coronary calcification (CAC) and bone histology. Methods: 101 hemodialysis patients were randomized for each phosphate binder and submitted to multislice coronary tomographies and bone biopsies at entry and 12 months. Results: The 71 patients who concluded the study had similar baseline characteristics. On follow-up, the sevelamer group had higher levels of intact parathyroid hormone (498 +/- 352 vs. 326 +/- 236 pg/ml, p = 0.017), bone alkaline phosphatase (38 +/- 24 vs. 28 +/- 15 U/l, p = 0.03) and deoxypyridinoline (135 +/- 107 vs. 89 +/- 71 nmol/l, p = 0.03) and lower LDL cholesterol (74 +/- 21 vs. 91 +/- 28 mg/dl, p = 0.015). Phosphorus (5.8 +/- 1.0 vs. 6 +/- 1.0 mg/dl, p = 0.47) and calcium (1.27 +/- 0.07 vs. 1.23 +/- 0.08 mmol/l, p = 0.68) levels did not differ between groups. CAC progression (35 vs. 24%, p = 0.94) and bone histological diagnosis at baseline and 12 months were similar in both groups. Patients of the sevelamer group with a high turnover at baseline had an increase in bone resorption (eroded surface, ES/BS = 9.0 +/- 5.9 vs. 13.1 +/- 9.5%, p = 0.05), whereas patients of both groups with low turnover at baseline had an improvement in bone formation rate (BFR/BS = 0.015 +/- 0.016 vs. 0.062 +/- 0.078, p = 0.003 for calcium and 0.017 +/- 0.016 vs. 0.071 +/- 0.084 mu m(3)/mu m(2)/day, p = 0.010 for sevelamer). Conclusions: There was no difference in CAC progression or changes in bone remodeling between the calcium and the sevelamer groups. Copyright (C) 2008 S. Karger AG, Basel

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Purpose The aim of this study was to test the correlation between Fourier-domain (FD) optical coherence tomography (OCT) macular and retinal nerve fibre layer (RNFL) thickness and visual field (VF) loss on standard automated perimetry (SAP) in chiasmal compression. Methods A total of 35 eyes with permanent temporal VF defects and 35 controls underwent SAP and FD-OCT (3D OCT-1000; Topcon Corp.) examinations. Macular thickness measurements were averaged for the central area and for each quadrant and half of that area, whereas RNFL thickness was determined for six sectors around the optic disc. VF loss was estimated in six sectors of the VF and in the central 16 test points in the VF. The correlation between VF loss and OCT measurements was tested with Spearman`s correlation coefficients and with linear regression analysis. Results Macular and RNFL thickness parameters correlated strongly with SAP VF loss. Correlations were generally stronger between VF loss and quadrantic or hemianopic macular thickness than with sectoral RNFL thickness. For the macular parameters, we observed the strongest correlation between macular thickness in the inferonasal quadrant and VF loss in the superior temporal central quadrant (rho=0.78; P<0.001) whereas for the RNFL parameters the strongest correlation was observed between the superonasal optic disc sector and the central temporal VF defect (rho=0.60; P<0.001).

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The objective of this study is to determine if digital vasculitis (DV), a clinical manifestation with a high systemic lupus erythematosus disease activity index (SLEDAI) score, is associated with lupus severity. DV and other clinical manifestations defined according to the SLEDAI were evaluated in 168 consecutive patients with systemic lupus erythematosus (SLE). Two groups were defined according to presence (DV+, n = 27) or absence of DV (DV-, n = 141) at the time of evaluation. The exclusion criterion was the presence of antiphospholipid syndrome (Sapporo`s criteria). The two groups were comparable with regard to age (P = 0.09), gender (P = 1.00), white race (P = 0.81), and disease duration (P = 0.78). Compared to the DV-group, the DV+ group had a significantly higher frequency of mucocutaneous manifestations (66.7 vs. 39.0%, P = 0.01), haematological abnormalities (22.2 vs. 6.4%, P = 0.02) and constitutional symptoms (11.1 vs. 0.7%, P = 0.01). Renal and neurological involvements were similar in both groups ( P = 0.57 and P = 1.00, respectively). The evaluation of each SLEDAI parameter confirmed that the DV+ group had higher frequencies of mild manifestations, such as new rash (P = 0.02), alopecia (P = 0.02), oral ulcers (P = 0.045), fever (P = 0.01) and leucopenia (P = 0.005). In contrast, both groups had similarly increased anti-dsDNA (P = 0.78) and decreased complement levels (P = 0.29). In conclusion, DV in patients with SLE identifies a subgroup of a mild disease. The high `weighted` index attributed to this alteration in the SLEDAI score should therefore be revised. Lupus (2009) 18, 990-993.

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The diagnosis of a catecholamine-secreting pheochromocytoma is always suggested by occurrence of severe and symptomatic paroxysmal hypertension. However, in most patients this diagnosis is not confirmed, despite extensive investigation.(1) Traditionally, besides pheochromocytoma, the differential diagnosis in cases of paroxysmal hypertension associated with catecholamine excess should include cocaine use, antiparkinsonian drugs, obstructive sleep apnoea and baroreflex failure.(2) Nonetheless, when the paroxysmal hypertension is associated not only with catecholamine excess, but also with neurologic signs, a very rare differential diagnosis should also be considered: a brainstem tumour mimicking pheochromocytoma.(3-5)

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We examined the effects of polyarticular juvenile idiopathic arthritis (pJIA) serum on proliferation, differentiation, mineralization, and apoptosis of human osteoblast cells (hOb) in culture. The hOb were cultured with 10% serum from active pJIA and healthy controls (CT) and were tested for DNA synthesis, alkaline phosphatase (AP) activity, osteocalcin (OC) secretion, calcium levels, caspase 3 activity, and DNA fragmentation. None of the patients had used glucocorticoids for at least 1 month before the study, or any other drug that can affect bone mineral metabolism. Human inflammatory cytokine levels (IL-6, IL-8, IL-10, IL-1 beta, TNF-alpha, and IL-12p70) were measured in pJIA and CT sera. Low levels of AP activity was observed in pJIA cultures compared with CT cultures (67.16 +/- 53.35 vs 100.11 +/- 50.64 mu mol p-nitrophenol/h(-1) mg(-1) protein, P=0.008). There was also a significant decrease in OC secretion (9.23 +/- 5.63 vs 12.82 +/- 7.02 ng/mg protein, P=0.012) and calcium levels (0.475 +/- 0.197 vs 0.717 +/- 0.366 mmol/l, P=0.05) in pJIA hOb cultures. No difference was observed in cell proliferation (323.56 +/- 108.23 vs 328.91 +/- 88.03 dpm/mg protein, P=0.788). Osteoblasts cultured with JIA sera showed lower levels of DNA and increased fragmentation than osteoblasts cultured with CT sera. pJIA sera showed higher IL-6 values than CT (21.44 +/- 9.31 vs 3.58 +/- 2.38 pg/ml, P<0.001), but no difference was observed related to IL-8, IL-10, IL-1 beta, TNF-alpha, and IL-12p70 between pJIA and controls. This study suggests that serum from children with pJIA inhibits differentiation, mineralization and may increase apoptosis of hOb cultures, and inflammatory cytokines such as IL-6 might be a mechanism in this find. These results may represent an alternative therapeutic target for prevention and treatment of bone loss in JIA.

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Menstrual cycles of 30 patients with juvenile systemic lupus erythematosus (JSLE) were compared with 30 age-matched controls. The mean age of patients with JSLE and controls was similar (17.4 +/- 3.2 vs 17.06 +/- 2.08 years, P = 0.66). The mean menarche age was higher in JSLE than controls (13.13 +/- 1.4 vs 11.56 +/- 1.5 years, P = 0.0008). On the contrary, the mean maternal menarche age was similar in both groups (P = 0.62). Menstrual abnormalities and longer length cycles were more frequently observed in JSLE than controls (63% vs 10%, P = 0.0001; 23% vs 0%, P = 0.0105, respectively). The median of follicle stimulating hormone was significantly higher in patients with JSLE compared with controls (4.6 vs 3.4 IU/L, P = 0.0207), and the median of progesterone was lower (32.5 vs 70 ng/mL, P = 0.0033). The median Of luteinizing hormone was lower in patients with JSLE with menstrual abnormalities versus normal cycles (2.9 vs 5.5 IU/L, P = 0.019) and both had a high percentage of decreased progesterone levels (63% vs 73%, P = 0.70). Our findings support the notion that menstrual disturbances are frequent and may be associated with pituitary dysfunction leading to a decreased progesterone production. We also reported that in spite of premature ovarian failure being a rare event in JSLE the follicular reserve seems to be low regardless of intravenous cyclophosphamide treatment. Lupus (2009) 18, 38-43.

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Reports on the use of sirolimus (SRL) in pancreas transplantation are still limited. The aim of this study was to evaluate the outcome of SRL conversion in pancreas transplant patients. Among 247 patients undergoing simultaneous kidney-pancreas or solitary pancreas transplantation, 33 (13%) were converted to SRL. The reasons for conversion were calcineurin inhibitors (CNI) nephrotoxicity (n = 24; 73%), severe neurotoxicity owing to CNI (n = 1; 3%), severe and/or recurrent acute rejection episodes (n = 7; 21.%), gastrointestinal (GI) side effects of mycophenolate mofetil (MMF; n = 5; 15%), and hyperglycemia (n = 4; 12%). Before conversion, all patients were maintained on a CNI, MMF, and low-dose steroids. They were gradually converted to SRL associated with either CNI or MMF withdrawal. Sixty-three percent (n = 15) of patients who were converted owing to CNI nephrotoxicity, showed stable or improved renal function. At 12 months after conversion, serum creatinine levels were significantly decreased in this group (2.2 +/- 0.5 vs 1.6 +/- 0.3 mg/dL; P = .001) and C-peptide values increased (2.9 +/- 1.1.1 vs 3.1 +/- 1.3 nmol/L; P = .01.8). The only patient with leucoencephalopathy showed improved neurologic status after SRL conversion. All patients converted to SRL because of GI side effects of MMF showed improvements, and none of those converted because of hyperglycemia experienced improvement. There were no episodes of acute rejection after conversion. We concluded that conversion to SRL in pancreas transplantation should be considered an important alternative strategy, particularly for CNI nephrotoxicity and neurotoxicity, and in cases of severe diarrhea due to MMF.