93 resultados para additive representability
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Eucalyptus camaldulensis has great importance in Brazil because of their phenotypic plasticity for different environmental conditions, as soils, altitudes and rainfall. This study is an investigation of a base population of E. camaldulensis from Australia through a progeny test implanted in Selviria, MS. The trial was established in a randomized block design, with 25 families and 60 replications of single tree plots. Genetic parameters for anatomic traits and volume shrinkage were estimated, as well as their correlations with wood basic density. No significant differences among progenies were observed for the traits studied. The additive genetic variation coefficient at individual and among progeny levels ranged from low (0.26%) to high (16.98%). The narrow sense heritability at individual and family means levels also ranged from low (0.01) to high (0.87). This indicates that some traits are under strong genetic control and can be improved by selection. In the present situation, in order to attain the highest genetic gains, the sequential selection among and within progeny would be recommended.
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A lipidic nanoemulsion termed LDE concentrates in neoplastic cells after injection into the bloodstream and thus can be used as a drug carrier to tumour sites. The chemotherapeutic agent daunorubicin associates poorly with LDE; the aim of this study was to clarify whether the derivatization of daunorubicin by the attachment of an oleyl group increases the association with LDE, and to test the cytotoxicity and animal toxicity of the new preparation. The association of oleyl-daunorubicin (oDNR) to LDE showed high yield (93 +/- 2% and 84 +/- 4% at 1:10 and 1:5 drug:lipid mass, respectively) and was stable for at least 20 days. Association with oDNR increased the LDE particle diameter from 42 +/- 4 nm to 75 +/- 6 nm. Cytotoxicity of LDE-oDNR was reduced two-fold in HL-60 and K-562 cell lines, fourteen-fold in B16 cells and nine-fold in L1210 cells when compared with commercial daunorubicin. When tested in mice, LDE-oDNR showed remarkable reduced toxicity (maximum tolerated dose > 253 mu mol kg(-1), compared with <3 mu mol kg(-1) for commercial daunorubicin). At high doses, the cardiac tissue of LDE-oDNR-treated animals had much smaller structural lesions than with commercial daunorubicin. LDE-oDNR is therefore a promising new preparation that may offer superior tolerability compared with commercial daunorubicin.
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Chagas disease is a serious health problem in Latin America. Hidroxymethylnitrofurazone (NFOH) is a nitrofurazone prodrug more active than nitrofurazone against Trypanosoma cruzi. However, NFOH presents low aqueous solubility, high photodecomposition and high toxicity. The present work is focused on the characterization of an inclusion complex of NFOH in 2-hydroxypropyl-beta-cyclodextrin (HP-beta-CD). The complexation with HP-beta-CD was investigated using reversed-phase liquid chromatography, solubility isotherms and nuclear magnetic resonance. The retention behavior was analyzed on a reversed-phase C-18 column, using acetonitrile-water (20/80, v/v) as the mobile phase, in which HP-beta-CD was incorporated as a mobile phase additive. The decrease in the retention times with increasing concentrations of HP-beta-CD enables the determination of the apparent stability constant of the complex (K = 6.2 +/- 0.3 M-1) by HPLC. The solubility isotherm was studied and the value for the apparent stability constant (K = 7.9 +/- 0.2 M-1) was calculated. The application of continuous variation method indicated the presence of a complex with 1:1 NFOH:HP-beta-CD stoichiometry. The photostability study showed that the formation of an inclusion complex had a destabilizing effect on the photodecomposition of NFOH when compared to that of the ""free"" molecule in solution. The mobility investigation (by NMR longitudinal relaxation time) gives information about the complexation of NFOH with HP-beta-CD. In preliminary toxicity studies, cell viability tests revealed that inclusion complexes were able to decrease the toxic effect (p < 0.01) caused by NFOH. (c) 2008 Elsevier B.V. All rights reserved.
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Nisin is a natural additive for conservation of food, and can also be used as a therapeutic agent. Nisin inhibits the outgrowth of spores, the growth of a variety of Gram-positive and Grain-negative bacteria. In this paper we present a potentially scalable and cost-effective way to purify commercial and biosynthesized in bioreactor nisin, including simultaneously removal of impurities and contaminants, increasing nisin activity. Aqueous two-phase micellar systems (ATPMS) are considered promising for bioseparation and purification purposes. Triton X-114 was chosen as the as phase-forming surfactant because it is relatively mild to proteins and it also forms two coexisting phases within a convenient temperature range. Nisin activity was determined by the agar diffusion assay utilizing Lactobacillus sake as a sensitive indicator microorganism. Results indicated that nisin partitions preferentially to the micelle rich-phase, despite the surfactant concentration tested, and its antimicrobial activity increases. The successful implementation of this peptide partitioning, from a suspension containing other compounds, represents an important step towards developing a separation method for nisin, and more generally, for other biomolecules of interest. (C) 2007 Elsevier Inc. All rights reserved.
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Chagas` disease is considered the sixth most important neglected tropical disease worldwide. Considerable knowledge has been accumulated concerning the role of zinc on cellular immunity. The steroid hormone dehydroepiandrosterone (DHEA) is also known to modulate the immune system. The aims of this paper were to investigate a possible synchronization of their effects on cytokines and NO production and the resistance to Trypanosoma cruzi during the acute phase of infection. It was found that zinc, DHEA or zinc and DHEA supplementation enhanced the immune response, as evidenced by a significant reduction in parasitemia levels. Zinc and DHEA supplementation exerted additive effects on the immune response by elevation of macrophage counts, and by increasing concentrations of IFN-gamma and NO. (C) 2009 Elsevier GmbH. All rights reserved.
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Objective-The goal of this study was to assess the independent and collective associations of hepatic steatosis, obesity, and the metabolic syndrome with elevated high-sensitivity C-reactive protein (hs-CRP) levels. Methods and Results-We evaluated 2388 individuals without clinical cardiovascular disease between December 2004 and December 2006. Hepatic steatosis was diagnosed by ultrasound, and the metabolic syndrome was defined using National Heart, Lung, and Blood Institute criteria. The cut point of >= 3 mg/L was used to define high hs-CRP. Multivariate logistic regression was used to assess the independent and collective associations of hepatic steatosis, obesity, and the metabolic syndrome with high hs-CRP. Steatosis was detected in 32% of participants, 23% met criteria for metabolic syndrome, and 17% were obese. After multivariate regression, hepatic steatosis (odds ratio [OR] 2.07; 95% CI 1.68 to 2.56), obesity (OR 3.00; 95% CI 2.39 to 3.80), and the metabolic syndrome (2.39; 95% CI 1.88 to 3.04) were all independently associated with high hs-CRP. Combinations of these factors were associated with an additive increase in the odds of high hs-CRP, with individuals with 1, 2, and 3 factors having ORs for high hs-CRP of 1.92 (1.49 to 2.48), 3.38 (2.50 to 4.57), and 4.53 (3.23 to 6.35), respectively. Conclusion-Hepatic steatosis, obesity, and the metabolic syndrome are independently and additively associated with increased odds of high hs-CRP levels. (Arterioscler Thromb Vasc Biol. 2011; 31: 1927-1932.)
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We investigated whether the administration of IL-2 combined with endostatin gene therapy was able to produce additive or even synergistic immunomodulatory activity in a mouse model of metastatic renal carcinoma. Renca cells were injected into the tail vein of BALB/c mice. After 24 h, the animals were randomly divided into four groups (5 mice/group). One group of mice was the control, the second group received treatment with 100,000 UI of Recombinant IL-2 (Proleukin, Chiron) twice a day, 1 day per week during 2 weeks (IL-2), the third group received treatment with a subcutaneous inoculation of 3.6 x 10(6) endostatin-producing cells, and the fourth group received both therapies (IL-2 + ES). Mice were treated for 2 weeks. In the survival studies, 10 mice/group daily, mice were monitored daily until they died. The presence of metastases led to a twofold increase in endostatin levels. Subcutaneous inoculation of NIH/3T3-LendSN cells resulted in a 2.75 and 2.78-fold increase in endostatin levels in the ES and IL-2 + ES group, respectively. At the end of the study, there was a significant decrease in lung wet weight, lung nodules area, and microvascular area (MVA) in all treated groups compared with the control group (P < 0.001). The significant difference in lung wet weight and lung nodules area between groups IL-2 and IL-2 + ES revealed a synergistic antitumor effect of the combined treatment (P < 0.05). The IL-2 + ES therapy Kaplan-Meier survival curves showed that the probability of survival was significantly higher for mice treated with the combined therapy (log-rank test, P = 0.0028). Conjugated therapy caused an increase in the infiltration of CD4, CD8 and CD49b lymphocytes. An increase in the amount of CD8 cells (P < 0.01) was observed when animals received both ES and IL-2, suggesting an additive effect of ES over IL-2 treatment. A synergistic effect of ES on the infiltration of CD4 (P < 0.001) and CD49b cells (P < 0.01) was also observed over the effect of IL-2. Here, we show that ES led to an increase in CD4 T helper cells as well as cytotoxic lymphocytes, such as NK cells and CD8 cells, within tumors of IL-2 treated mice. This means that ES plays a role in supporting the actions of T cells.
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TRAPS is the most common of the autosomal dominant periodic fever syndromes. It is caused by mutations in the TNFRSF1A gene, which encodes for the type 1 TNF-receptor (TNFR1). We describe here a Brazilian patient with TRAPS associated to a novel TNFRSF1A de novo mutation and the response to anti-TNF therapy. The patient is a 9-year-old girl with recurrent fevers since the age of 3 years, usually lasting 3 to 7 days, and recurring every other week. These episodes are associated with mild abdominal pain, nausea, vomiting and generalized myalgia. Recurrent conjunctivitis and erysipela-like skin lesions in the lower limbs also occur. Laboratory studies show persistent normocytic normochromic anemia, thrombocytosis, elevated erythrocyte sedimentation rate and C-reactive protein. IgD levels are normal. Mutational screening of TNFRSF1A revealed the association of a novel C30F mutation with the common R92Q low-penetrance mutation. The R92Q mutation is seen in 5% of the general population and is associated with an atypical inflammatory phenotype. The patient had a very good response to etanercept, with cessation of fever and normalization of inflammatory markers. Our report expands the spectrum of TNFRSF1A mutations associated with TRAPS, adding further evidence for possible additive effects of a low-penetration R92Q and cysteine residue mutations, and confirms etanercept as an efficacious treatment alternative.
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Introduction: The ACCM/PALS guidelines address early correction of paediatric septic shock using conventional measures. In the evolution of these recommendations, indirect measures of the balance between systemic oxygen delivery and demands using central venous or superior vena cava oxygen saturation ( ScvO(2) >= 70%) in a goal-directed approach have been added. However, while these additional goal-directed endpoints are based on evidence-based adult studies, the extrapolation to the paediatric patient remains unvalidated. Objective: The purpose of this study was to compare treatment according to ACCM/PALS guidelines, performed with and without ScvO(2) goal-directed therapy, on the morbidity and mortality rate of children with severe sepsis and septic shock. Design, participants and interventions: Children and adolescents with severe sepsis or fluid-refractory septic shock were randomly assigned to ACCM/PALS with or without ScvO(2) goal-directed resuscitation. Measurements: Twenty-eight-day mortality was the primary endpoint. Results: Of the 102 enrolled patients, 51 received ACCM/PALS with ScvO(2) goal-directed therapy and 51 received ACCM/PALS without ScvO(2) goal-directed therapy. ScvO(2) goal-directed therapy resulted in less mortality ( 28-day mortality 11.8% vs. 39.2%, p = 0.002), and fewer new organ dysfunctions ( p = 0.03). ScvO(2) goal-directed therapy resulted in more crystalloid ( 28 ( 20-40) vs. 5 ( 0-20) ml/kg, p < 0.0001), blood transfusion ( 45.1% vs. 15.7%, p = 0.002) and inotropic ( 29.4% vs. 7.8%, p = 0.01) support in the first 6 h. Conclusions: This study supports the current ACCM/PALS guidelines. Goal-directed therapy using the endpoint of a ScvO(2) = 70% has a significant and additive impact on the outcome of children and adolescents with septic shock.
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Objective Obstructive sleep apnea (OSA) and hypertension (HYP) frequently coexist and have additive harmful effects on the cardiovascular system. There is also growing evidence that short sleep duration may contribute independently to poor cardiovascular outcome. The aim of this study was to evaluate the potential influence of antihypertensive medication on sleep parameters objectively measured by standard polysomnography in hypertensive patients with OSA. Methods We evaluated consecutive patients with a recent diagnosis of OSA by full polysomnography (apnea hypopnea index >= 5 events/h) and HYP. Smokers, patients with diabetes mellitus, heart failure, or using hypnotics and benzodiazepines were excluded. Results We evaluated 186 hypertensive patients with OSA, 64% men. All patients were on at least one antihypertensive medication, including angiotensin-converting enzyme inhibitors (37%), beta-blockers (35%), angiotensin receptor blockers (32%), diuretics (29%) and calcium channel blockers (21%). Backward multiple regression analysis showed that age (P <= 0.001) and the use of calcium channel blockers (P=0.037) were the only factors inversely associated with lower total sleep time. Sleep efficiency was inversely associated only with age (P <= 0.001), whereas the use of calcium channel blockers had a nonsignificant trend (P=0.092). Use of calcium channel blockers was associated with significant reduction in total sleep time (-41 min, P=0.005) and 8% lower sleep efficiency (P=0.004). No other antihypertensive medication, including diuretics and beta-blockers, was associated with sleep impairment. Conclusion Calcium channel blockers may impact negatively on sleep duration in hypertensive patients with OSA. The mechanisms and significance of this novel finding warrants further investigation. J Hypertens 29: 1236-1241 (C) 2011 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.
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OBJECTIVE: Investigate the effects of antenatal steroids and tracheal occlusion on pulmonary expression of vascular endothelial growth factor receptors in rats with nitrofen-induced congenital diaphragmatic hernia. STUDY DESIGN: Fetuses were exposed to nitrofen at embryonic day 9.5. Subgroups received dexamethasone or were operated on for tracheal occlusion, or received combined treatment. Morphologic variables were recorded. To analyze vascular endothelial growth factor receptor 1 and vascular endothelial growth factor receptor 2 expression, we performed Western blotting and immunohistochemistry. Morphologic variables were analyzed by analysis of variance and immunohistochemistry by Kruskal-Wallis test. RESULTS: Congenital diaphragmatic hernia decreased body weight, total lung weight, and lung-to-body weight ratio. Tracheal occlusion increased total lung weight and lung-to-body weight ratio (P < .05). Fetuses with congenital diaphragmatic hernia had reduced vascular endothelial growth factor receptor 1 and vascular endothelial growth factor receptor 2 expression, whereas steroids and tracheal occlusion increased their expression. Combined treatment increased expression of receptors, but had no additive effect. CONCLUSION: Vascular endothelial growth factor signaling disruption may be associated with pulmonary hypertension in congenital diaphragmatic hernia. Tracheal occlusion and steroids provide a pathway for restoring expression of vascular endothelial growth factor receptors.
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We analyzed the effect of (+)alpha-tocopheryl succinate (alpha-TOS) alone or associated with arsenic trioxide (ATO) or all-trans retinoid acid (ATRA) in acute promyelocytic leukemia (APL). alpha-TOS-induced apoptosis in APL clinical samples and in ATRA-sensitive (NB4) and ATRA-resistant (NB4-R2) APL cell lines. The effective dose 50% (ED-50) was calculated to be 71 and 58 mu M, for NB4 and NB4-R2, respectively. a-TOS neither induced nor modified ATRA-induced differentiation of APL cells, and did not affect the proliferation and differentiation of normal CD34(+) hematopoietic progenitors in methylcellulose assays. alpha-TOS exerted a moderate antagonistic effect to ATO-induced apoptosis when treatment was done simultaneously but when alpha-TOS was added 24 h after ATO, an additive effect was observed. Our results support the concept of alpha-TOS as an anti-leukemic compound which spares normal hematopoiesis. (C) 2008 Elsevier Ltd. All rights reserved.
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The objective of this study was to estimate (co)variance functions using random regression models on Legendre polynomials for the analysis of repeated measures of BW from birth to adult age. A total of 82,064 records from 8,145 females were analyzed. Different models were compared. The models included additive direct and maternal effects, and animal and maternal permanent environmental effects as random terms. Contemporary group and dam age at calving (linear and quadratic effect) were included as fixed effects, and orthogonal Legendre polynomials of animal age (cubic regression) were considered as random co-variables. Eight models with polynomials of third to sixth order were used to describe additive direct and maternal effects, and animal and maternal permanent environmental effects. Residual effects were modeled using 1 (i.e., assuming homogeneity of variances across all ages) or 5 age classes. The model with 5 classes was the best to describe the trajectory of residuals along the growth curve. The model including fourth- and sixth-order polynomials for additive direct and animal permanent environmental effects, respectively, and third-order polynomials for maternal genetic and maternal permanent environmental effects were the best. Estimates of (co) variance obtained with the multi-trait and random regression models were similar. Direct heritability estimates obtained with the random regression models followed a trend similar to that obtained with the multi-trait model. The largest estimates of maternal heritability were those of BW taken close to 240 d of age. In general, estimates of correlation between BW from birth to 8 yr of age decreased with increasing distance between ages.
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We undertook a field study to determine whether comb cell size affects the reproductive behavior of Varroa destructor under natural conditions. We examined the effect of brood cell width on the reproductive behavior of V. destructor in honey bee colonies, under natural conditions. Drone and worker brood combs were sampled from 11 colonies of Apis mellifera. A Pearson correlation test and a Tukey test were used to determine whether mite reproduction rate varied with brood cell width. Generalized additive model analysis showed that infestation rate increased positively and linearly with the width of worker and drone cells. The reproduction rate for viable mother mites was 0.96 viable female descendants per original invading female. No significant correlation was observed between brood cell width and number of offspring of V. destructor. Infertile mother mites were more frequent in narrower brood cells.
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Compound forms of Charcot-Marie-Tooth (CMT) disease have been recently associated with unusually severe neuropathies, an observation that prompted the proposition that the additive effects of two mutations should be searched in patients whose clinical severity falls outside the common CMT phenotypes. In this report, we present a father and a daughter with a very mild and unusual disease that segregates with two mutations in PMP22 gene, the 17p11.2-p12 duplication and a Ser72Leu point mutation. We propose that the deleterious effects of each mutation are partially compensated by the functional effect of the other.