85 resultados para IS Function


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Rapid alkalinization factor (RALF) is part of a growing family of small peptides with hormone characteristics in plants. Initially isolated from leaves of tobacco plants, RALF peptides can be found throughout the plant kingdom and they are expressed ubiquitously in plants. We took advantage of the small gene family size of RALF genes in sugarcane and the ordered cellular growth of the grass sugarcane leaves to gain information about the function of RALF peptides in plants. Here we report the isolation of two RALF peptides from leaves of sugarcane plants using the alkalinization assay. SacRALF1 was the most abundant and, when added to culture media, inhibited growth of microcalli derived from cell suspension cultures at concentrations as low as 0.1 mu M. Microcalli exposed to exogenous SacRALF1 for 5 days showed a reduced number of elongated cells. Only four copies of SacRALF genes were found in sugarcane plants. All four SacRALF genes are highly expressed in young and expanding leaves and show a low or undetectable level of expression in expanded leaves. In half-emerged leaf blades, SacRALF transcripts were found at high levels at the basal portion of the leaf and at low levels at the apical portion. Gene expression analyzes localize SacRALF genes in elongation zones of roots and leaves. Mature leaves, which are devoid of expanding cells, do not show considerable expression of SacRALF genes. Our findings are consistent with SacRALF genes playing a role in plant development potentially regulating tissue expansion.

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The Brazil nut (Bertholletia excelsa) of the Amazon region is consumed worldwide. It is rich in both monounsaturated fatty acids and polyunsaturated fatty acids and is known for its high selenium content. This study tested the hypothesis whether the consumption of this nut could affect the plasma lipids and apolipoproteins and some functional properties of the antiatherogenic high-density lipoprotein (HDL). Fifteen normolipidemic subjects aged 27.3 +/- 3.9 years and with body mass index of 23.8 +/- 2.8 kg/m(2) consumed 45 g of Brazil nuts per day during a 15-day period. On days 0 and 15, blood was collected for biochemical analysis, determination of HDL particle size, paraoxonase 1 activity, and lipid transfer from a lipoprotein-like nanoparticle to the HDL fraction. Brazil nut ingestion did not alter HDL, low-density lipoprotein cholesterol, triacylglycerols, apolipoprotein A-1, or apolipoprotein B concentrations. HDL particle diameter and the activity of antioxidative paraoxonase 1, mostly found in the HDL fraction, Were also unaffected. Supplementation increased the reception of cholesteryl esters (P <.05) by the HDL yet did not alter the reception of phospholipids, free cholesterol, or triacylglycerols. As expected, plasma selenium was significantly increased. However, the consumption of Brazil nuts for short duration by normolipidemic subjects in comparable amounts to those tested for other nuts did not alter serum lipid profile. The only alteration in HDL function was the increase in cholesteryl ester transfer. This latter finding may be beneficial because it would improve the nonatherogenic reverse cholesterol transport pathway. (c) 2008 Elsevier Inc. All rights reserved.

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Objective: Glutamine is one of the most abundant amino acids found in maternal milk, and its concentration increases throughout lactation. Because glutamine is essential for macrophage functionality, it is hereby suggested that early weaning in conjunction with the absence of glutamine consumption impairs the functioning of macrophages, which could in turn be reversed with an in vitro supplementation with glutamine. Methods: Swiss Webster mice were early weaned at 14 d of age (EW group) or at 21 d of age (control group, n = 8 per group). The EW group was fed a glutamine-free diet from days 14 to 21 of life. Results: Mice in the EW group presented a significant decrease in plasma and muscle concentrations of glutamine and an increase in the activity of glutamine synthetase in the muscle. Peritoneal macrophages obtained from animals in the EW group presented a significant increase in the production of interleukin (IL)-10 and a significant decrease in the synthesis of IL-1 beta, IL-6, tumor necrosis factor-a, nitric oxide, and hydrogen peroxide and in their ability to adhere, spread, phagocytize, and kill fungi. Glutamine in vitro supplementation reversed the decrease in IL-6, nitric oxide, and hydrogen peroxide synthesis and the decrease in the capacity to adhere, spread, and phagocytize in animals of the EW group. Conclusion: These new. data may imply that a lack of glutamine intake in early weaned mice hampers the functioning of peritoneal macrophages. (C) 2008 Elsevier Inc. All rights reserved.

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Homocysteine is an independent risk factor for coronary heart disease, as well as for cerebrovascular and peripheral vascular diseases. The purpose of this study was to investigate the effects of hyperhomocysteinemia (HHcy) on vascular reactivity within carotid artery segments isolated from ovariectomized female rats. Treatment with dl-Hcy thiolactone (1 g/kg body weight per day) reduced the phenylephrine-induced contraction of denuded rings. However, the treatment did not alter KCl-induced contractions, or relaxations induced by sodium nitroprusside or acetylcholine. We report elevated expressions of iNOS, eNOS, and nitrotyrosine in homocysteine-treated rat artery sections. Moreover, the inhibition of NOS by l-NAME, 1,400 W, or l-NNA restored phenylephrine-induced vasoconstriction in carotid artery segments from Hcy-treated rats. In conclusion, our findings show that severe HHCy can promote an acute decrease in the endothelium-independent contractile responses of carotid arteries to adrenergic agonists. This effect was restored by nitric oxide synthase inhibitors, which further supports the involvement of nitric oxide in HHcy-derived vascular dysfunction.

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Nitric oxide (NO) in NTS plays an important role in regulating autonomic function to the cardiovascular system. Using the fluorescent dye DAF-2 DA, we evaluated the NO concentration in NTS. Brainstem slices of rats were loaded with DAF-2 DA, washed, fixed in paraformaldehyde and examined under fluorescent light. In different experimental groups, NTS slices were pre-incubated with 1 mM L-NAME (a non-selective NOS inhibitor), 1 MM D-NAME (an inactive enantiomere of L-NAME), 1 mM kynurenic acid (a nonselective ionotropic receptors antagonist) or 20 mu M bicuculline (a selective GABA(A) receptors antagonist) before and during DAF-2 DA loading. Images were acquired using a confocal microscope and the intensity of fluorescence was quantified in three antero-posterior NTS regions. In addition, slices previously loaded with DAF-2 DA were incubated with NeuN or GFAP antibody. A semi-quantitative analysis of the fluorescence intensity showed that the basal NO concentration was similar in all antero-posterior aspects of the NTS (rostral intermediate, 15.5 +/- 0.8 AU: caudal intermediate, 13.2 +/- 1.4 AU; caudal commissural, 13.8 +/- 1.4 AU, n = 10). In addition, the inhibition of NOS and the antagonism of glutamatergic receptors decreased the NO fluorescence in the NTS. On the other hand, D-NAME did not affect the NO fluorescence and the antagonism of GABAA receptors increased the NO fluorescence in the NTS. It is important to note that the fluorescence for NO was detected mainly in neurons. These data show that the fluorescence observed after NTS loading with DAF-2 DA is a result of NO present in the NTS and support the concept that NTS neurons have basal NO production which is modulated by L-glutamate and GABA. (C) 2009 Elsevier Inc. All rights reserved.

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This article aims to analyse the introduction of environmental issues in the context of the production function, which has been referred to as the organisational area to lead corporate environmental management. With that purpose, the theoretical references for corporate environmental management and the necessary alterations in production function have been organised to include environmental aspects, especially in terms of product and process development, quality management, and logistics. Considering that this research field still lacks empirical evidence for Brazilian companies, four case studies were conducted using companies located in the country. The environmental management maturity level of those companies tends to follow the rate with which the environmental issue is introduced in production sub-areas, especially in the product development process. However, in most cases we found that the companies had difficulties in structuring the insertion of the environmental dimension in logistics. The final notes point out the distance observed between what is recommended by international literature and the reality of Brazilian companies in the challenge of making the production function environmentally friendly.

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In insects, exoskeleton (cuticle) formation at each molt cycle includes complex biochemical pathways wherein the laccase enzymes (EC 1.10.3.2) may have a key role. We identified an Amlac2 gene that encodes a laccase2 in the honey bee, Apis mellifera, and investigated its function in exoskeleton differentiation. The Amlac2 gene consists of nine exons resulting in an ORE of 2193 nucleotides. The deduced translation product is a 731 amino acid protein of 81.5 kDa and a pl of 6.05. Amlac2 is highly expressed in the integument of pharate adults, and the expression precedes the onset of cuticle pigmentation and the intensification of sclerotization. In accordance with the temporal sequence of exoskeleton differentiation from anterior to posterior direction, the levels of Amlac2 transcript increase earlier in the thoracic than in the abdominal integument. The gene expression lasts even after the bees emerge from brood cells and begin activities in the nest, but declines after the transition to foraging stage, suggesting that maturation of the exoskeleton is completed at this stage. Post-transcriptional knockdown of Amlac2 gene expression resulted in structural abnormalities in the exoskeleton and drastically affected adult eclosion. By setting a ligature between the thorax and abdomen of early pupae we could delay the increase in hemolymph ecdysteroid levels in the abdomen. This severely impaired the increase in Amlac2 transcript levels and also the differentiation of the abdominal exoskeleton. Taken together, these results indicate that Amlac2 expression is controlled by ecdysteroids and has a critical role in the differentiation of the adult exoskeleton of honey bees. (C) 2010 Elsevier Ltd. All rights reserved.

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The switch from within-hive activities to foraging behavior is a major transition in the life cycle of a honeybee (Apis mellifera) worker. A prominent regulatory role in this switch has long been attributed to juvenile hormone (JH), but recent evidence also points to the yolk precursor protein vitellogenin as a major player in behavioral development. In the present study, we injected vitellogenin double-stranded RNA (dsVg) into newly emerged worker bees of Africanized genetic origin and introduced them together with controls into observation hives to record flight behavior. RNA interference-mediated silencing of vitellogenin gene function shifted the onset of long-duration flights (> 10 min) to earlier in life (by 3-4 days) when compared with sham and untreated control bees. In fact, dsVg bees were observed conducting such flights extremely precociously, when only 3 days old. Short-duration flights (< 10 min), which bees usually perform for orientation and cleaning, were not affected. Additionally, we found that the JH titer in dsVg bees collected after 7 days was not significantly different from the controls. The finding that depletion of the vitellogenin titer can drive young bees to become extremely precocious foragers could imply that vitellogenin is the primary switch signal. At this young age, downregulation of vitellogenin gene activity apparently had little effect on the JH titer. As this unexpected finding stands in contrast with previous results on the vitellogenin/JH interaction at a later age, when bees normally become foragers, we propose a three-step sequence in the constellation of physiological parameters underlying behavioral development.

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Bariatric surgery in morbidly obese type 2 diabetic (T2DM) patients is associated with high rates of diabetes remission. We investigated the mechanisms of the anti-diabetic effect of the laparoscopic ileal interposition with sleeve gastrectomy (LII-SG) in normal weight (NW), overweight (OW) and obese (OB) T2DM patients. Ninety-four patients (aged 54 +/- 8 years) with long-standing (median 10 years), treated diabetes (median HbA(1c) = 8.6%), who were NW (15), OW (64) or OB (15) based on BMI, underwent LII-SG. Insulin sensitivity and parameters of -cell function were measured from an Oral Glycaemic Tolerance Test pre- and post-operatively. At a median of 13.4 months post-operatively, weight loss averaged 9.4 +/- 1.3, 16.8 +/- 0.8 and 23.2 +/- 1.7 kg in NW, OW and OB subjects, respectively (p < 0.0001). Insulin sensitivity was fully restored (395 [108] vs 208 [99] ml min(-1) m(-2)), fasting insulin secretion rate decreased (68 [52] vs 146 [120] pmol min(-1) m(-2)) and total insulin output increased (52 [26] vs 39 [28] nmol m(-2), all p a parts per thousand currency signaEuro parts per thousand 0.001). -cell glucose sensitivity doubled (37 [33] vs 18 [24] mol min(-1) m(-2) mM(-1), p < 0.0001). The only parameter predicting remission of diabetes was a lower baseline insulin sensitivity (p = 0.005). LII-SG induced changes on T2DM by mechanisms in part distinct from weight loss, principally involving restoration of insulin sensitivity and improvement of -cell function.

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OBJECTIVE: Phrenic nerve transfer has been used for treating lesions of the brachial plexus since 1970. Although, today, surgeons are more experienced with the technique, there are still widespread concerns about its effects on pulmonary function. This study was undertaken to evaluate the effectiveness and safety of this procedure. METHODS: Fourteen patients with complete palsy of the upper limb were submitted to phrenic nerve transfer as part of a strategy for surgical reconstruction of their plexuses. Two patients were lost to follow-up, and 2 patients were followed for less than 2 years. Of the remaining 10 patients, 9 (90%) were male. The lesions affected both sides equally. The mean age of the patients was 24.8 years (range, 14-43 years), and the mean interval from injury to surgery was 6 months (range, 3-9 months). The phrenic nerve was always transferred to the musculocutaneous nerve, and a nerve graft (mean length, 8 cm; range, 4.5-12 cm) was necessary in all cases. RESULTS: There was no major complication related to the surgery. Seven patients (70%) recovered functional level biceps strength (Medical Research Council grade >= 3). All of the patients exhibited a transient decrease in pulmonary function tests, but without clinical respiratory problems. CONCLUSION: On the basis of our small series and data from the literature, we conclude that phrenic nerve transfer in well-selected patients is a safe and effective procedure for recovering biceps function.

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Radiofirequency ablation of the pulmonary veins has been used to treat patients with paroxysmal atrial fibrillation (AF), and atrial damage after ablation is an issue of concern. To evaluate left atrial function shortly and midterm after ablation, 33 consecutive patients with paroxysmal AF were studied at baseline, 24 hours, and >= 6 months after ablation. Patients in sinus rhythm with normal ventricular function were included in the study. Echocardiographic measurements of left atrial volumes (Simpson`s rule) and transmitral and tissue Doppler myocardial (A`) velocities at the septal and lateral mitral annulus were undertaken at each time. Left atrial emptying fraction (EF; maximal - minimal left atrial volume/maximal left atrial volume) was used to express left atrial function. After 8 +/- 2 months, 30 of 33 patients returned (23 men, age 53 +/- 13 years), and all except 2 were in sinus rhythm. Shortly after ablation, left atrial minimal volumes increased (from 30 +/- 15 to 35 +/- 15 ml; p = 0.02), with maximal volumes unchanged, resulting in decreased left atrial EF (from 47 +/- 8 to 40 +/- 7 ml; p <0.05). Tissue Doppler septal A` velocities also decreased (from 8.2 +/- 1.8 to 6.9 +/- 2.0 cm/s; p <0.05). However, after midterm follow-up, both left atrial EF and septal A` velocities had slightly increased compared with shortly after ablation, although left atrial volumes remained similar to baseline. Septal A` velocity changes paralleled left atrial EF both shortly (r = 0.46, p = 0.02) and at midterm after ablation (r = 0.47, p = 0.01). In conclusion, after radiofrequency ablation, patients with paroxysmal AF experienced an initial impairment in atrial function, with improvement at longer term follow-up. (C) 2009 Elsevier Inc. All rights reserved. (Am J Cardiol 2009;103: 395-398)

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Objective. To assess the testicular Sertoli cell function in male SLE patients. Methods. Thirty-four consecutive patients were prospectively selected to evaluate serum inhibin B. Clinical features, treatment, semen analysis, urological evaluation, testicular ultrasound, hormones and anti-sperm antibodies were determined. Results. Patients were subdivided into two groups: low serum inhibin B (Group 1, n = 8) and normal levels (Group 2, n 26). The median sperm concentration (P = 0.024), total sperm count (P = 0.023) and total motile sperm count (P = 0.025) were lower in Group 1. Inhibin B levels were positively correlated with sperm concentration (r = 0.343), total motile sperm count (r = 0.357), and negatively correlated with follicule-stimulating hormone (FSH) (r = 0.699) and luteinizing hormone (r = 0.397). The median serum inhibin B was lower in SLE patients treated with intravenous cyclophosphamide (IVCYC) compared with those without this therapy (P = 0.031). Further evaluation of the 26 SLE patients with normal inhibin B and FSH levels revealed that medians of inhibin B/FSH ratio were lower in SLE patients with oligozoospermia compared with normozoospermia (P = 0.004). This ratio was also lower in SLE patients treated with IVCYC than those without this therapy (P = 0.04). In contrast, inhibin B serum level alone did not discriminate the later group of patients (P = 0.12). Conclusions. This is the first study to identify a high frequency of testicular Sertoli cell dysfunction in male SLE associated with semen abnormalities. Further prospective studies are necessary to determine if inhibin levels and inhibin B/FSH ratio will be an earlier and useful marker of IVCYC toxicity in these patients.

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A number of studies conducted in humans and in animals have observed that events occurring early in life are associated with the development of diseases in adulthood. Salt overload and restriction during pregnancy and lactation are responsible for functional (hemodynamic and hormonal) and structural alterations in adult offspring. Our group observed that lower birth weight and insulin resistance in adulthood is associated with salt restriction during pregnancy On the other hand, perinatal salt overload is associated with higher blood pressure and higher renal angiotensin II content in adult offspring. Therefore, we hypothesised that renin-angiotensin system (RAS) function is altered by changes in sodium intake during pregnancy. Such changes may influence fetoplacental blood flow and thereby fetal nutrient supply, with effects on growth in utero and, consequently, on birth weight. Female Wistar rats were fed low-salt (LS), normal-salt (NS), or high-salt (HS) diet, starting before conception and continuing until day 19 of pregnancy, Blood pressure, heart rate, fetuses and dams` body weight, placentae weight and litter size were measured on day 19 of pregnancy. Cardiac output, uterine and placental blood flow were also determined on day 19. Expressions of renin-angiotensin system components and of the TNF-alpha gene were evaluated in the placentae. Plasma renin activity (PRA) and plasma and tissue angiotensin-converting enzyme (ACE) activity, as well as plasma and placental levels of angiotensins I, II, and 1-7 were measured. Body weight and kidney mass were greater in HS than in NS and LS dams. Food intake did not differ among the maternal groups. Placental weight was lower in LS dams than in NS and HS dams. Fetal weight was lower in the US group than in the NS and HS groups. The PRA was greater in IS dams than in NS and HS dams, although ACE activity (serum, cardiac, renal, and placental) was unaffected by the level of sodium intake. Placental levels of angiotensins I and II were lower in the HS group than in the ISIS and IS groups. Placental angiotensin receptor type 1 (AT(1)) gene expression and levels of thiobarbituric acid reactive substances (TBARS) were higher in HS dams, as were uterine blood flow and cardiac output. The degree of salt intake did not influence plasma sodium, potassium or creatinine. Although fractional sodium excretion was higher in HS dams than in NS and LS dams, fractional potassium excretion was unchanged. In conclusion, findings from this study indicate that the reduction in fetal weight in response to salt restriction during pregnancy does not involve alterations in uterine-placental perfusion or the RAS. Moreover, no change in fetal weight is observed in response to salt overload during pregnancy. However, salt overload did lead to an increase in placental weight and uterine blood flow associated with alterations in maternal plasma and placental RAS. Therefore, these findings indicate that changes in salt intake during pregnancy lead to alterations in uterine-placental perfusion and fetal growth. (C) 2008 Elsevier Inc. All rights reserved.

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The level of fractional exhaled nitric oxide (FENO) is significantly elevated in uncontrolled asthma and decreases after anti-inflammatory therapy The aim of this prospective study was to analyze the behavior of FENO in the follow-up and management of the inflammation in asthmatic pediatric patients treated with inhaled corticosteroids (ICS), compared to sputum cellularity, serum interleukins (IL), and pulmonary function. Twenty-six clinically stable asthmatic children aged from 6 to 18 years, previously treated or not with ICS were included. Following an international consensus (GINA), the patients were submitted to standard treatment with inhaled fluticasone for 3 months according to the severity of the disease. During this period, each patient underwent three assessments at intervals of approximately 6 weeks: Each evaluation consisted of the measurement of FENO, determination of serum interleukins IL-5, IL-10, IL-13, and interferon gamma (INF-gamma), spirometry and cytological analysis of spontaneous or induced sputum. A significant reduction in mean FENO and IL-5, without concomitant changes in FEV1, was observed along the study. There was no significant correlation between FeNO and FEV1 in the three assessments. A significant correlation between FeNO and IL-5 levels was only observed in the third assessment (r = 0.499, P=0.025). In most patients, serum IL-10, IL-13, and INF-gamma concentrations were undetectable throughout the study Sputum samples were obtained spontaneously in 11 occasions and in 56 by induction with 3% hypertonic saline solution (success rate: 50.8%), with 39 (69.9%) of them adequate for analysis. Only two of the 26 patients produced adequate samples in the three consecutive evaluations, which impaired the determination of a potential association between sputum cellularity and FeNO levels throughout the study. In conclusion, among the parameters of this study, it was difficult to perform and to interpret the serial analysis of spontaneous or induced sputum. Serum interleukins, which remained at very low or undetectable levels in most patients, were not found to be useful for therapeutic monitoring, except for IL-5 that seems to present some correlation with levels of FeNO exhaled. Monitoring of the mean FEV1 indicated no significant variations during the treatment, demonstrating that functional stability or the absence of obstruction may not reflect the adequate management of asthma. Serial measurement of FeNO seemed to best reflect the progressive anti-inflammatory action of ICS in asthma.

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Creatine supplementation may have a therapeutic role in diabetes, but it is uncertain whether this supplement is safe for kidney function. The aim of this study was to investigate the effects of creatine supplementation on kidney function in type 2 diabetic patients. A randomized, double-blind, placebo-controlled trial was performed. The patients were randomly allocated to receive either creatine or placebo for 12 weeks. All the patients underwent exercise training throughout the trial. Subjects were assessed at baseline and after the intervention. Blood samples and 24-h urine samples were obtained for kidney function assessments. Additionally, (51)Cr-EDTA clearance was performed. To ensure the compliance with creatine intake, we also assessed muscle phosphorylcreatine content. The creatine group presented higher muscle phosphorylcreatine content when compared to placebo group (CR Pre 44 +/- A 10, Post 70 +/- A 18 mmol/kg/wt; PL Pre 52 +/- A 13, Post 46 +/- A 13 mmol/kg/wt; p = 0.03; estimated difference between means 23.6; 95% confidence interval 1.42-45.8). No significant differences were observed for (51)Cr-EDTA clearance (CR Pre 90.4 +/- A 16.9, Post 96.1 +/- A 15.0 mL/min/1.73 m(2); PL Pre 97.9 +/- A 21.6, Post 96.4 +/- A 26.8 mL/min/1.73 m(2); p = 0.58; estimated difference between means -0.3; 95% confidence interval -24.9 to 24.2). Creatinine clearance, serum and urinary urea, electrolytes, proteinuria, and albuminuria were unchanged. CR supplementation does not affect kidney function in type 2 diabetic patients, opening a window of opportunities to explore its promising therapeutic role in this population. ClinicalTrials.gov registration number: NCT00992043.