106 resultados para LEVEL VARIATIONS


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Crown group Archosauria, which includes birds, dinosaurs, crocodylomorphs, and several extinct Mesozoic groups, is a primary division of the vertebrate tree of life. However, the higher-level phylogenetic relationships within Archosauria are poorly resolved and controversial, despite years of study. The phylogeny of crocodile-line archosaurs (Crurotarsi) is particularly contentious, and has been plagued by problematic taxon and character sampling. Recent discoveries and renewed focus on archosaur anatomy enable the compilation of a new dataset, which assimilates and standardizes character data pertinent to higher-level archosaur phylogeny, and is scored across the largest group of taxa yet analysed. This dataset includes 47 new characters (25% of total) and eight taxa that have yet to be included in an analysis, and total taxonomic sampling is more than twice that of any previous study. This analysis produces a well-resolved phylogeny, which recovers mostly traditional relationships within Avemetatarsalia, places Phytosauria as a basal crurotarsan clade, finds a close relationship between Aetosauria and Crocodylomorpha, and recovers a monophyletic Rauisuchia comprised of two major subclades. Support values are low, suggesting rampant homoplasy and missing data within Archosauria, but the phylogeny is highly congruent with stratigraphy. Comparison with alternative analyses identifies numerous scoring differences, but indicates that character sampling is the main source of incongruence. The phylogeny implies major missing lineages in the Early Triassic and may support a Carnian-Norian extinction event.

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Serotonin (5-HT) plays a key role in the neural circuitry mediating unconditioned and conditioned fear responses related to panic and generalized anxiety disorders. The basolateral nucleus of the amygdala (BLA) and the dorsal periaqueductal gray (dPAG) appear to be mainly involved in these conditions. The aim of this study was to measure the extracellular level of 5-HT and its metabolite 5-hydroxyindolacetic acid (5-HIAA) in the BLA and dPAG during unconditioned and conditioned fear states using in vivo microdialysis procedure. Thus, for the unconditioned fear test, animals were chemically stimulated in the dPAG with semicarbazide, an inhibitor of the gamma-aminobutyric acid-synthesizing enzyme glutamic acid decarboxylase. For the conditioned fear test, animals were subjected to a contextual conditioned fear paradigm using electrical footshock as the unconditioned stimulus. The results show that the 5-HT and 5-HIAA level in the BLA and dPAG did not change during unconditioned fear, whereas 5-HT concentration, but not 5-HIAA concentration, increased in these brain areas during conditioned fear. The present study showed that the 5-HT system was activated during conditioned fear, whereas it remained unchanged during unconditioned fear, supporting the hypothesis that 5-HT has distinct roles in conditioned and unconditioned fear (dual role of 5-HT in anxiety disorders). (C) 2009 Elsevier B.V. All rights reserved.

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Background/Aims: The use of low-level laser therapy (LLLT) in neurosurgery is still hardly disseminated and there are situations in which the effects of this therapeutic tool would be extremely relevant in this medical field. The aim of the present study is to analyze the effect of LLLT on tissue repair after the corrective surgical incision in neonates with myelomeningocele, in an attempt to diminish the incidence of postoperative dehiscences following surgical repair performed immediately after birth. Materials and Methods: Prospective pilot study with 13 patients submitted to surgery at birth who received adjuvant treatment with LLLT (group A). A diode laser CW, lambda = 685 nm, p = 21 mW, was applied punctually along the surgical incision, with 0.19 J delivered per point, accounting for a total of 4-10 J delivered energy per patient, according to the surgical wound area and then compared with the results obtained in 23 patients who underwent surgery without laser therapy (group B). Results: This pilot study disclosed a significant decline in dehiscences of the surgical wounds in neonates who were submitted to LLLT (7.69 vs. 17.39%). Conclusion: This new adjuvant therapeutic modality with LLLT aided the healing of surgical wounds, preventing morbidities, as well as shortening the period of hospital stay, which implies a reduction of costs for patients and for the institution. Copyright (C) 2010 S. Karger AG, Basel

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Background and objectives: As well as being a marker of body iron stores, serum ferritin (sFerritin) has also been shown to be a marker of inflammation in hemodialysis (HD) patients. The aim of this study was to analyze whether sFerritin is a reliable marker of the iron stores present in bone marrow of HD patients. Design: Histomorphometric analysis of stored transiliac bone biopsies was used to assess iron stores by determining the number of iron-stained cells per square millimeter of bone marrow. Results: In 96 patients, the laboratory parameters were hemoglobin = 11.3 +/- 1.6 g/dl, hematocrit = 34.3 +/- 5%, sFerritin 609 +/- 305 ng/ml, transferrin saturation = 32.7 +/- 22.5%, and C-reactive protein (CRP) = 0.9 +/- 1.4 mg/dl. sFerritin correlated significantly with CRP, bone marrow iron, and time on HD treatment W = 0.006, 0.001, and 0.048, respectively). The independent determinants of sFerritin were CRP (beta-coef = 0.26; 95% CI = 24.6 to 132.3) and bone marrow iron (beta-coef = 0.32; 95% CI = 0.54 to 2.09). Bone marrow iron was higher in patients with sFerritin >500 ng/ml than in those with sFerritin :5500 ng/ml. In the group of patients with sFerritin :5500 ng/ml, the independent determinant of sFerritin was bone marrow iron (beta-coef = 0.48, 95% CI = 0.48 to 1.78), but in the group of patients with sFerritin >500 ng/ml, no independent determinant of sFerritin was found. Conclusions: sFerritin adequately reflects iron stores in bone marrow of HD patients.

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Background-Randomized trials that studied clinical outcomes after percutaneous coronary intervention (PCI) with bare metal stenting versus coronary artery bypass grafting (CABG) are underpowered to properly assess safety end points like death, stroke, and myocardial infarction. Pooling data from randomized controlled trials increases the statistical power and allows better assessment of the treatment effect in high-risk subgroups. Methods and Results-We performed a pooled analysis of 3051 patients in 4 randomized trials evaluating the relative safety and efficacy of PCI with stenting and CABG at 5 years for the treatment of multivessel coronary artery disease. The primary end point was the composite end point of death, stroke, or myocardial infarction. The secondary end point was the occurrence of major adverse cardiac and cerebrovascular accidents, death, stroke, myocardial infarction, and repeat revascularization. We tested for heterogeneities in treatment effect in patient subgroups. At 5 years, the cumulative incidence of death, myocardial infarction, and stroke was similar in patients randomized to PCI with stenting versus CABG (16.7% versus 16.9%, respectively; hazard ratio, 1.04, 95% confidence interval, 0.86 to 1.27; P = 0.69). Repeat revascularization, however, occurred significantly more frequently after PCI than CABG (29.0% versus 7.9%, respectively; hazard ratio, 0.23; 95% confidence interval, 0.18 to 0.29; P<0.001). Major adverse cardiac and cerebrovascular events were significantly higher in the PCI than the CABG group (39.2% versus 23.0%, respectively; hazard ratio, 0.53; 95% confidence interval, 0.45 to 0.61; P<0.001). No heterogeneity of treatment effect was found in the subgroups, including diabetic patients and those presenting with 3-vessel disease. Conclusions-In this pooled analysis of 4 randomized trials, PCI with stenting was associated with a long-term safety profile similar to that of CABG. However, as a result of persistently lower repeat revascularization rates in the CABG patients, overall major adverse cardiac and cerebrovascular event rates were significantly lower in the CABG group at 5 years.

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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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Radiation dose calculations in nuclear medicine depend on quantification of activity via planar and/or tomographic imaging methods. However, both methods have inherent limitations, and the accuracy of activity estimates varies with object size, background levels, and other variables. The goal of this study was to evaluate the limitations of quantitative imaging with planar and single photon emission computed tomography (SPECT) approaches, with a focus on activity quantification for use in calculating absorbed dose estimates for normal organs and tumors. To do this we studied a series of phantoms of varying complexity of geometry, with three radionuclides whose decay schemes varied from simple to complex. Four aqueous concentrations of (99m)Tc, (131)I, and (111)In (74, 185, 370, and 740 kBq mL(-1)) were placed in spheres of four different sizes in a water-filled phantom, with three different levels of activity in the surrounding water. Planar and SPECT images of the phantoms were obtained on a modern SPECT/computed tomography (CT) system. These radionuclides and concentration/background studies were repeated using a cardiac phantom and a modified torso phantom with liver and ""tumor"" regions containing the radionuclide concentrations and with the same varying background levels. Planar quantification was performed using the geometric mean approach, with attenuation correction (AC), and with and without scatter corrections (SC and NSC). SPECT images were reconstructed using attenuation maps (AM) for AC; scatter windows were used to perform SC during image reconstruction. For spherical sources with corrected data, good accuracy was observed (generally within +/- 10% of known values) for the largest sphere (11.5 mL) and for both planar and SPECT methods with (99m)Tc and (131)I, but were poorest and deviated from known values for smaller objects, most notably for (111)In. SPECT quantification was affected by the partial volume effect in smaller objects and generally showed larger errors than the planar results in these cases for all radionuclides. For the cardiac phantom, results were the most accurate of all of the experiments for all radionuclides. Background subtraction was an important factor influencing these results. The contribution of scattered photons was important in quantification with (131)I; if scatter was not accounted for, activity tended to be overestimated using planar quantification methods. For the torso phantom experiments, results show a clear underestimation of activity when compared to previous experiment with spherical sources for all radionuclides. Despite some variations that were observed as the level of background increased, the SPECT results were more consistent across different activity concentrations. Planar or SPECT quantification on state-of-the-art gamma cameras with appropriate quantitative processing can provide accuracies of better than 10% for large objects and modest target-to-background concentrations; however when smaller objects are used, in the presence of higher background, and for nuclides with more complex decay schemes, SPECT quantification methods generally produce better results. Health Phys. 99(5):688-701; 2010

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Background and Objectives: Chronic autoimmune thyroiditis (CAT) remains the most common cause of acquired hypothyroidism There is currently no therapy that is capable of regenerating CAT-damaged thyroid tissue The objective of this study was to gauge the value of applying low-level laser therapy (LLLT) in CAT patients based on both ultrasound studies (USs) and evaluations of thyroid function and thyroid autoantibodies. Study Design/Materials and Methods: Fifteen patients who had hypothyroidism caused by CAT and were undergoing levothyroxine (LT4) treatment were selected to participate in the study Patients received 10 applications of LLLT (830 nm, output power 50 mW) in continuous mode, twice a week, using either the punctual technique (8 patients) or the sweep technique (7 patients), with fluence in the range of 38-108 J/cm(2) USs were performed prior to and 30 days after LLLT USs included a quantitative analysis of echogenicity through a gray-scale computerized histogram index (El). Following the second ultrasound (30 days after LLLT), LT4 was discontinued in all patients and, if required, reintroduced Truodothyronine, thyroxine (T4), free T4, thyrotropin, thyroid peroxidase (TPOAb) and thyroglobulin (TgAb) antibodies levels were assessed before LLLT and then 1, 2, 3, 6, and 9 months after LT4 withdrawal. Results: We noted all patients` reduced LT4 dosage needs, including 7 (47%) who did not require any LT4 through the 9-month follow-up The LT4 dosage used pre-LLLT (96 +/- 22 mu g/day) decreased in the 9th month of follow-up (38 23 mu g/day; P<0.0001) TPOAb levels also decreased (pre-LLLT = 982 +/- 530 U/ml, post-LLLT = 579 454 U/ml, P = 0 016) TgAb levels were not reduced, though we did observe a post-LLLT increase in the EI (pre-LLLT = 0 99 +/- 0.09, post-LLLT= 1.21 +/- 0.19, P=0.001) Conclusion: The preliminary results indicate that LLLT promotes the improvement of thyroid function, as patients experienced a decreased need for LT4, a reduction in TPOAb levels, and an increase in parenchymal echogenicity Lasers Surg. Med. 42:589-596, 2010. (C) 2010 Wiley-Liss, Inc

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Background: Current evidence suggests an inverse association between socioeconomic status and stroke incidence. Our aim was to measure the variation in incidence among different city districts (CD) and their association with socioeconomic variables. Methods: We prospectively ascertained all possible stroke cases occurring in the city of Joinville during the period 2005-2007. We determined the incidence for each of the 38 CD, age-adjusted to the population of Joinville. By linear regression analysis, we correlated incidence data with mean years of education (MYE) and mean income per month (MIPM). Results: Of the 1,734 stroke cases registered, 1,034 were first-ever strokes. In the study period, the crude incidence in Joinville was 69.5 per 100,000 (95% confidence interval, 65.3-73.9). The stroke incidence among CD ranged from 37.5 (22.2-64.6) to 151.0 per 100,000 (69.0-286.6). The stroke incidence was inversely correlated with years of education (r = -0.532; p<0.001). MYE and MIPM were strongly related (R = 0.958), resulting in exclusion of MIPM by collinearity. Conclusions: Years of education can explain a wide incidence variation among CD. These results may be useful to guide the allocation of resources in primary prevention policies. Copyright (C) 2011 S. Karger AG, Basel

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Objectives. The aim of the present study is to investigate serum BDNF levels in older depressed patients as compared to healthy elderly controls. Methods. Twenty-nine elderly subjects with major depression and 42 healthy older adults were enrolled to this study. All depressed patients were antidepressant-free for at least 1 month prior clinical and laboratorial assessments. Serum BDNF levels were determined by sandwich ELISA. Results. BDNF levels were lower in elderly depressed patients as compared to controls (P = 0.034). Patients with late-onset depression had the lowest BDNF level (median 478.5, interquartile range 373.5-740.9 pg/l) when compared to early-onset depression (median 620.7, interquartile range 366.1-971.9 pg/l) and healthy controls (median 711.3, interquartile range 534.7-1181.0 pg/l) (P < 0.03). Conclusions. Reduced serum BDNF level may be a state marker of late-life depression in non-medicated elderly patients. Our findings provide further evidences that reduced neurotrophic support may have an important role in the physiopathology of late-life depression.

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The activation of inflammatory cascades has been consistently demonstrated in the pathophysiology of Alzheimer`s disease (AD). Among several putative neuroinflammatory mechanisms, the tumor necrosis factor alpha (TNF-alpha) signaling system has a central role in this process. Recent evidence indicates that the abnormal production of inflammatory factors may accompany the progression from mild cognitive impairment (MCI) to dementia. We aimed to examine serum levels of TNF-alpha and its soluble receptors (sTNFR1 and sTNFR2) in patients with MCI and AD as compared to cognitively unimpaired elderly subjects. We further aimed to investigate whether abnormal levels of these cytokines predict the progression from MCI to AD upon follow-up. We utilized cross-sectional determination of serum levels of TNF-alpha, sTNFR1, and sTNFR2 (ELISA method) in a test group comprising 167 older adults (31 AD, 72 MCI, and 64 healthy controls), and longitudinal reassessment of clinical status after 18.9 +/- 10.0 months. At baseline, there were no statistically significant differences in serum TNF-alpha, sTNFR1, and sTNFR2 between patients with MCI and AD as compared to controls. Nevertheless, patients with MCI who progressed to AD had significantly higher serum sTNFR1 levels as opposed to patients who retained the diagnosis of MCI upon follow-up (p = 0.03). Cox regression analysis showed that high serum sTNFR1 levels predicted the conversion from MCI to AD (p = 0.003), whereas no significant differences were found with respect to serum levels of TNF-alpha and sTNFR2. Abnormal activation of TNF-alpha signaling system, represented by increased expression of sTNFR1, is associated with a higher risk of progression from MCI to AD.

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The persistent nature of addiction has been associated with activity-induced plasticity of neurons within the striatum and nucleus accumbens (NAc). To identify the molecular processes leading to these adaptations, we performed Cre/loxP-mediated genetic ablations of two key regulators of gene expression in response to activity, the Ca2+/calmodulin-dependent protein kinase IV (CaMKIV) and its postulated main target, the cAMP-responsive element binding protein (CREB). We found that acute cocaine-induced gene expression in the striatum was largely unaffected by the loss of CaMKIV. On the behavioral level, mice lacking CaMKIV in dopaminoceptive neurons displayed increased sensitivity to cocaine as evidenced by augmented expression of locomotor sensitization and enhanced conditioned place preference and reinstatement after extinction. However, the loss of CREB in the forebrain had no effect on either of these behaviors, even though it robustly blunted acute cocaine-induced transcription. To test the relevance of these observations for addiction in humans, we performed an association study of CAMK4 and CREB promoter polymorphisms with cocaine addiction in a large sample of addicts. We found that a single nucleotide polymorphism in the CAMK4 promoter was significantly associated with cocaine addiction, whereas variations in the CREB promoter regions did not correlate with drug abuse. These findings reveal a critical role for CaMKIV in the development and persistence of cocaine-induced behaviors, through mechanisms dissociated from acute effects on gene expression and CREB-dependent transcription.

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Queiroz BC, Cagliari MF, Amorim CF, Sacco IC. Muscle activation during four Pilates core stability exercises in quadruped position. Arch Phys Med Rehabil 2010;91: 86-92. Objective: To compare the activity of stabilizing trunk and hip muscles in 4 variations of Pilates stabilizing exercises in the quadruped position. Design: Repeated-measures descriptive study. Setting: A biomechanics laboratory at a university school of medicine. Participants: Healthy subjects (N=19; mean age +/- SD, 31 +/- 5y; mean weight +/- SD, 60 +/- 11 kg; mean height +/- SD, 166 +/- 9cm) experienced in Pilates routines. Interventions: Surface electromyographic signals of iliocostalis, multifidus, gluteus maximus, rectus abdominis, and external and internal oblique muscles were recorded in 4 knee stretch exercises: retroverted pelvis with flexed trunk; anteverted pelvis with extended trunk; neutral pelvis with inclined trunk; and neutral pelvis with trunk parallel to the ground. Main Outcome Measures: Root mean square values of each muscle and exercise in both phases of hip extension and flexion, normalized by the maximal voluntary isometric contraction. Results: The retroverted pelvis with flexed trunk position led to significantly increased external oblique and gluteus maximus muscle activation. The anteverted pelvis with trunk extension significantly increased multifidus muscle activity. The neutral pelvis position led to significantly lower activity of all muscles. Rectus abdominis muscle activation to maintain body posture was similar in all exercises and was not influenced by position of the pelvis and trunk. Conclusions: Variations in the pelvic and trunk positions in the knee stretch exercises change the activation pattern of the multifidus, gluteus maximus, rectus abdominis, and oblique muscles. The lower level of activation of the rectus abdominis muscle suggests that pelvic stability is maintained in the 4 exercise positions.

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Background/Aims: Abnormal inflammatory response has been associated to the pathogenesis of Alzheimer`s disease (AD) and may be a marker of an ongoing neurodegenerative process. The aim of this study was to evaluate the serum levels of interleukin-1 beta (IL-1 beta) in patients with mild cognitive impairment (MCI) and AD. Methods: One hundred and sixty-three older adults ( 58 with mild to moderate AD, 74 with MCI and 31 healthy controls) were recruited for this study. Serum IL-1 beta levels were measured by ELISA. Patients with MCI were subcategorized in single-domain amnestic (aMCI), nonamnestic (naMCI), and multiple-domain (mdMCI) subtypes. Results: Patients with AD and MCI ( all subtypes) had a significant increase in serum IL-1 beta levels as compared to controls (p = 0.03). Patients with mdMCI had serum IL-1 beta levels comparable to those with AD, and significantly higher than those observed in aMCI and naMCI ( p = 0.02). Discussion: The present study provides evidence that inflammatory mechanisms, represented by elevated IL-1 beta, are observed in patients with MCI, specifically in those with impairment in multiple cognitive domains. As these patients are at higher risk of conversion to dementia, we propose that an increased serum IL-1 beta level is a stage marker of the ongoing brain neurodegeneration in the continuum between normal ageing and AD. Copyright (C) 2009 S. Karger AG, Basel

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Objective: To compare the triggering performance of mid-level ICU mechanical ventilators with a standard ICU mechanical ventilator. Design: Experimental bench study. Setting: The respiratory care laboratory of a university-affiliated teaching hospital. Subject: A computerized mechanical lung model, the IngMar ASL5000. Interventions: Ten mid-level ICU ventilators were compared to an ICU ventilator at two levels of lung model effort, three combinations of respiratory mechanics (normal, COPD and ARDS) and two modes of ventilation, volume and pressure assist/control. A total of 12 conditions were compared. Measurements and main results: Performance varied widely among ventilators. Mean inspiratory trigger time was < 100 ms for only half of the tested ventilators. The mean inspiratory delay time (time from initiation of the breath to return of airway pressure to baseline) was longer than that for the ICU ventilator for all tested ventilators except one. The pressure drop during triggering (Ptrig) was comparable with that of the ICU ventilator for only two ventilators. Expiratory Settling Time (time for pressure to return to baseline) had the greatest variability among ventilators. Conclusions: Triggering differences among these mid-level ICU ventilators and with the ICU ventilator were identified. Some of these ventilators had a much poorer triggering response with high inspiratory effort than the ICU ventilator. These ventilators do not perform as well as ICU ventilators in patients with high ventilatory demand.