97 resultados para Circadian Variation


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BACKGROUND: Alcoholic beverages may have protective cardiovascular effects but are known to increase the plasma levels of triglycerides (TG). Both TG and the ratio of TO to high-density lipoprotein cholesterol (TG/HDL-cholesterol) are associated with increased cardiovascular risk. OBJECTIVES: To determine the predictive factors for variations in plasma levels of TO and the TG/HDL-cholesterol ratio in patients after they had consumed red wine for 14 days. METHODS: Forty-two subjects (64% men, 46 +/- 9 years, baseline body mass index [BMI] 25.13 +/- 2.76 kg/m(2)) were given red wine (12% or 12.2% alc/vol, 250 mL/day with meals). Plasma concentration of lipids and glucose were measured before and after red wine consumption. Blood was collected after 12 hours of fast and alcohol abstention. RESULTS: Red wine increased plasma levels of TO from 105 +/- 42 mg/dL to 120 +/- 56 mg/dL (P = .001) and the TG/HDL-cholesterol ratio from 2.16 +/- 1.10 to 2.50 +/- 1.66 (P = .014). In a multivariate linear regression model that included age, baseline BMI, blood pressure, lipids, and glucose, only BMI was independently predictive of the variation in plasma TO after red wine (beta coefficient 0.592, P < .001). BMI also predicted the variation in TG/HDL-cholesterol ratio (beta coefficient 0.505, P = .001, adjusted model). When individuals were divided into three categories, according to their BMI, the average percentage variation in TG after red wine was -4%, 17%, and 33% in the lower (19.60-24.45 kg/m(2)), intermediate, and greater (26.30-30.44 kg/m(2)) tertiles, respectively (P = .001). CONCLUSIONS: Individuals with higher BMI, although nonobese, might be at greater risk for elevation in plasma TO levels and the TG/HDL-cholesterol ratio after short-term red wine consumption. (C) 2011 National Lipid Association. All rights reserved.

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Objectives We studied the relationship between changes in body composition and changes in blood pressure levels. Background The mechanisms underlying the frequently observed progression from pre-hypertension to hypertension are poorly understood. Methods We examined 1,145 subjects from a population-based survey at baseline in 1994/1995 and at follow-up in 2004/2005. First, we studied individuals pre-hypertensive at baseline who, during 10 years of follow-up, either had normalized blood pressure (PreNorm, n = 48), persistently had pre-hypertension (PrePre, n = 134), or showed progression to hypertension (PreHyp, n = 183). In parallel, we studied predictors for changes in blood pressure category in individuals hypertensive at baseline (n = 429). Results After 10 years, the PreHyp group was characterized by a marked increase in body weight (+5.71% [95% confidence interval (CI): 4.60% to 6.83%]) that was largely the result of an increase in fat mass (+17.8% [95% CI: 14.5% to 21.0%]). In the PrePre group, both the increases in body weight (+1.95% [95% CI: 0.68% to 3.22%]) and fat mass (+8.09% [95% CI: 4.42% to 11.7%]) were significantly less pronounced than in the PreHyp group (p < 0.001 for both). The PreNorm group showed no significant change in body weight (-1.55% [95% CI: -3.70% to 0.61%]) and fat mass (+0.20% [95% CI: -6.13% to 6.52%], p < 0.05 for both, vs. the PrePre group). Conclusions After 10 years of follow-up, hypertension developed in 50.1% of individuals with pre-hypertension and only 6.76% went from hypertensive to pre-hypertensive blood pressure levels. An increase in body weight and fat mass was a risk factor for the development of sustained hypertension, whereas a decrease was predictive of a decrease in blood pressure. (J Am Coll Cardiol 2010; 56: 65-76) (C) 2010 by the American College of Cardiology Foundation

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Purpose: The aim of this study was to investigate the impact of acute PaCO(2) temporal variation on the standard base excess (SBE) value in critically ill patients. Methods: A total of 265 patients were prospectively observed; 158 were allocated to the modeling group, and 107 were allocated to the validation group. Two models were developed in the modeling group (one including and one excluding PaCO(2) as a variable determinant of SBE), and both were tested in the validation group. Results: In the modeling group, the mathematical model including SIDai, SIG, L-lactate, albumin, phosphate, and PaCO(2) had a predictive superiority in comparison with the model without PaCO(2) (R(2) = 0.978 and 0.916, respectively). In the validation group, the results were confirmed with significant F change statistics (R(2) change = 0.059, P < .001) between the model with and without PaCO(2). A high correlation (R = 0.99, P < .001) and agreement (bias = -0.25 mEq/L, limits of agreement 95% = -0.72 to 0.22 mEq/L) were found between the model-predicted SBE value and the SBE calculated using the Van Slyke equation. Conclusions: Acute PaCO(2), temporal variation is related to SBE changes in critically ill patients. (C) 2009 Elsevier Inc. All rights reserved.

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OBJECTIVE: A giant fusiform aneurysm in the posterior cerebral artery (PCA) is rare, as is fenestration of the PCA and basilar apex variation. We describe the angiographic and surgical findings of a giant fusiform aneurysm in the P1-P2 PCA segment associated with PCA bilateral fenestration and superior cerebellar artery double origin. CLINICAL PRESENTATION: A 26-year-old woman presented with a 2-month history of visual blurring. Digital subtraction angiography showed a giant (2.5 cm) fusiform PCA aneurysm in the right P1-P2 segment. The 3-dimensional view showed a caudal fusion pattern from the upper portion of the basilar artery associated with a bilateral long fenestration of the P1 and P2 segments and superior cerebellar artery double origin. INTERVENTION: Surgical trapping of the right P1 -P2 segment, including the posterior communicating artery, was performed by a pretemporal approach. Angiograms performed 3 and 13 months after surgery showed complete aneurysm exclusion, and the PCA was permeated and filled the PCA territory. Clinical follow-up at 14 months showed the patient with no deficits and a return to normal life. CONCLUSION: To our knowledge, this is the first report of a giant fusiform aneurysm of the PCA associated with P1-P2 segment fenestration and other variations of the basilar apex (bilateral superior cerebellar artery duplication and caudal fusion). Comprehension of the embryology and anatomy of the PCA and its related vessels and branches is fundamental to the decision-making process for a PCA aneurysm, especially when parent vessel occlusion is planned.

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Background and objective: Dynamic indices represented by systolic pressure variation and pulse pressure variation have been demonstrated to be more accurate than filling pressures in predicting fluid responsiveness. However, the literature is scarce concerning the impact of different ventilatory modes on these indices. We hypothesized that systolic pressure variation or pulse pressure variation could be affected differently by volume-controlled ventilation and pressure-controlled ventilation in an experimental model, during normovolaemia and hypovolaemia. Method: Thirty-two anaesthetized rabbits were randomly allocated into four groups according to ventilatory modality and volaemic status where G1-ConPCV was the pressure-controlled ventilation control group, G2-HemPCV was associated with haemorrhage, G3-ConVCV was the volume-controlled ventilation control group and G4-HemVCV was associated with haemorrhage. In the haemorrhage groups, blood was removed in two stages: 15% of the estimated blood volume withdrawal at M1, and, 30 min later, an additional 15% at M2. Data were submitted to analysis of variance for repeated measures; a value of P < 0.05 was considered to be statistically significant. Results: At MO (baseline), no significant differences were observed among groups. At M1, dynamic parameters differed significantly among the control and hypovolaemic groups (P < 0.05) but not between ventilation modes. However, when 30% of the estimated blood volume was removed (M2), dynamic parameters became significantly higher in animals under volume-controlled ventilation when compared with those under pressure-controlled ventilation. Conclusions: Under normovolaemia and moderate haemorrhage, dynamic parameters were not influenced by either ventilatory modalities. However, in the second stage of haemorrhage (30%), animals in volume-controlled ventilation presented higher values of systolic pressure variation and pulse pressure variation when compared with those submitted to pressure-controlled ventilation.

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Objectives To determine the effects of low-dose transdermal hormone therapy (HT) on systolic (SBP) and diastolic (DBP) blood pressure (BP) evaluated by 24-h ambulatory blood pressure monitoring (ABPM) in hypertensive postmenopausal women. Methods The study was conducted on 24 hypertensive postmenopausal women aged, on average, 54 years and under treatment with enalapril maleate (10-20 mg/day) combined or not with hydrochlorothiazide (25 mg/day). Thirteen women used a transdermal adhesive containing estradiol and norethisterone (25 and 125 mu g active substance/day, respectively) and 11 did not receive HT. ABPM, lipid profile, and climacteric symptoms were evaluated before and 3 and 6 months after treatment. Results After 3 and 6 months of follow-up, there was a statistically significant reduction of the Blatt-Kupperman menopausal index in the treated group (19.6 +/- 8.3 vs. 9.6 +/- 5.9 vs. 9.7 +/- 7.0; P=0.01). No significant difference in any of the ABPM variables (areas under the systolic and diastolic curves, mean SBP and DBP, SBP and DBP loads and wakefulness-sleep variation) or in the lipid profile was observed between or within groups at the three time points studied. Conclusion Low-dose transdermal HT administered for 6 months was effective in improving climacteric symptoms and did not change BP values or circadian pattern in postmenopausal women with mild-to-moderate arterial hypertension taking antihypertensive medications.

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Background & aim: Many disease outbreaks of food origin are caused by foods prepared in Food Service and Nutrition Units of hospitals, affecting hospitalized patients who, in most cases, are immunocompromised and therefore at a higher risk of severe worsening of their clinical status. The aim of this study was to determine the variations in temperature and the time-temperature factor of hospital diets. Methods: The time and temperature for the preparation of 4 diets of modified consistency were determined on 5 nonconsecutive days in a hospital Diet and Nutrition Unit at the end of preparation and during the maintenance period, portioning and distribution at 3 sites, i.e., the first, the middle and the last to receive the diets. Results and discussion: All foods reached an adequate temperature at the end of cooking, but temperature varied significantly from the maintenance period to the final distribution, characterizing critical periods for microorganism proliferation. During holding, temperatures that presented a risk were reached by 16.7% of the meats and 59% of the salads of the general diet, by 16.7% of the garnishes in the bland diet and by 20% of the meats and garnishes in the viscous diet. The same occurred at the end of distribution for 100% of the hot samples and of the salads and for 61% of the desserts. None of the preparations remained at risk temperature for a time exceeding that established by law. Conclusion: The exposure to inadequate temperature did not last long enough to pose risks to the patient.

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Previous studies have demonstrated that the pharmacological activities displayed by Bothrops jararaca venom undergo a significant ontogenetic shift. Variation in the venom proteome is a well-documented phenomenon; however, variation in the venom peptidome is poorly understood. We report a comparative proteomic and peptidomic analysis of venoms from newborn and adult specimens of B. jararaca and correlate it with the evaluation of important venom features. We demonstrate that newborn and adult venoms have similar hemorrhagic activities, while the adult venom has a slightly higher lethal activity in mice; however, the newborn venom is extremely more potent to kill chicks. The coagulant activity of newborn venom upon human plasma is 10 times higher than that of adult venom. These differences were clearly reflected in their different profiles of SDS-PAGE, gelatin zimography, immunostaining using specific antibodies, glycosylation pattern, and concanavalin A-binding proteins. Furthermore, we report for the first time the analysis of the peptide fraction of newborn and adult venoms by MALDI-TOF mass spectrometry and LC-MS/MS, which revealed different contents of peptides, while the bradykinin potentiating peptides (BPPs) showed rather similar profiles and were detected in the venoms showing their canonical sequences and also novel sequences corresponding to BPPs processed from their precursor protein at sites so far not described. As a result of these studies, we demonstrated that the ontogenetic shift in diet, from ectothermic prey in early life to endothermic prey in adulthood, and in animal size are associated with changes in the venom proteome in B. jararaca species.

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The alpha-lactalbumin is a subunit of lactose-synthase, an enzyme responsible for lactose production, a disaccharide that influences milk production. Sequence variations of bovine alpha-lactalbumin have been associated with differences in milk yield. This study aimed to analyze allelic frequency differences at position-1689 (g. AG) and+15 (g. AG) of the alpha-lactalbumin gene in Holstein (Bos taurus) and Nellore (Bos indicus) cows. Blood samples were analyzed from 34 Holstein, 104 Nellore, and 99 Dairy Nellore cows using PCR-RFLP. The different RFLP patterns were sequenced and a novel sequence variation on nucleotide-46 was identified. An adenine at this position was designated as the A allele and a guanine was designated B allele. The frequencies of alleles A-1689, A-46, and A+15 differed between Holstein and both Nellore breeds. The results show that differences in alpha-lactalbumin allelic variants in the 5`-flanking and the 5`-UTR region might be associated with differences in milk production between Holstein cows and cows from Nellore breeds. However, the lack of difference between Nellore and Dairy Nellore suggests that other sequence variantions that regulate milk production might be responsible for the selection of Dairy Nellore cows with superior milk production.

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Statement of the Problem: Adhesive systems can spread differently onto a substrate and, consequently, influence bonding. Purpose: The purpose of this study was to evaluate the effect of differently oriented dentin surfaces and the regional variation of specimens on adhesive layer thickness and microtensile bond strength (MTBS). Materials and Methods: Twenty-four molars were sectioned mesiodistally to expose flat buccal and lingual halves. Standardized drop volumes of adhesive systems (Single Bond [SB] and Prime & Bond 2.1 [PB2.1]) were applied to dentin according to the manufacturer`s instructions. Teeth halves were randomly divided into groups: 1A-SB/parallel to gravity; 1B-SB/perpendicular to gravity; 2A-PB2.1/parallel to gravity; and 2B-PB2.1/perpendicular to gravity. The bonded assemblies were stored in 37 degrees C distilled water for 24 hours and then sectioned to obtain dentin sticks (0.8 mm(2)). The adhesive layer thickness was determined in a light microscope (x200), and after 48 hours the specimens were subjected to MTBS test. Data were analyzed by one-way and two-way analysis of variance and Student-Newman-Keuls tests. Results: Mean values (MPa +/- SD) of MTBS were: 39.1 +/- 12.9 (1A); 32.9 +/- 12.4 (1B); 52.9 +/- 15.2 (2A); and 52.3 +/- 16.5 (2B). The adhesive systems` thicknesses (mu m +/- SD) were: 11.2 +/- 2.9 (1A); 18.1 +/- 7.3 (1B); 4.2 +/- 1.8 (2A); and 3.9 +/- 1.3 (2B). No correlation between bond strength and adhesive layer thickness for both SB and PB2.1 (r = -0.224, p = 0.112 and r = 0.099, p = 0.491, respectively) was observed. Conclusions: The differently oriented dentin surfaces and the regional variation of specimens on the adhesive layer thickness are material-dependent. These variables do not influence the adhesive systems` bond strength to dentin. CLINICAL SIGNIFICANCE Adhesive systems have different viscosities and spread differently onto a substrate, influencing the bond strength and also the adhesive layer thickness. Adhesive thickness does not influence dentin bond strength, but it may impair adequate solvent evaporation, polymer conversion, and may also determine water sorption and adhesive degradation over time. In the literature, many studies have shown that the adhesive layer is a permeable membrane and can fail over timebecause ofits continuous plasticizing and degradation when in contact with water. Therefore, avoiding thick adhesive layers may minimize these problems and provide long-term success for adhesive restorations.

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A secretory surge of prolactin occurs on the afternoon of oestrous in cycling rats. Although prolactin is regulated by ovarian steroids, plasma oestradiol and progesterone levels do not vary during oestrous. Because prolactin release is tonically inhibited by hypothalamic dopamine and modulated by dopamine transmission in the preoptic area (POA), the present study aimed to evaluate whether oestrogen receptor (ER)-alpha and progestin receptor (PR) expression in the dopaminergic neurones of arcuate (ARC), periventricular, anteroventral periventricular (AVPe) and ventromedial preoptic (VMPO) nuclei changes during the day of oestrous. Cycling rats were perfused every 2 h from 10-20 h on oestrous. Brain sections were double-labelled to ER alpha or PR and tyrosine hydroxylase (TH). The number of TH-immunoreactive (ir) neurones did not vary significantly in any area evaluated. ER alpha expression in TH-ir neurones increased at 14 and 16 h in the rostral-ARC and dorsomedial-ARC, 14 h in the caudal-ARC and 16 h in the VMPO, whereas it was unaltered in the ventrolateral-ARC, periventricular and AVPe. PR expression in TH-ir neurones of the periventricular and rostral, dorsomedial, ventrolateral and caudal-ARC decreased transitorily during the afternoon, showing the lowest levels between 14 and 16 h; but it did not vary in the AVPe and VMPO. Plasma oestradiol and progesterone concentrations were low and unaltered during oestrous, indicating that the changes in receptors expression were probably not due to variation in ligand levels. Thus, our data suggest that variations in ER alpha and PR expression may promote changes in the activity of medial basal hypothalamus and POA dopaminergic neurones, even under unaltered secretion of ovarian steroids, which could facilitate the occurrence and modulate the magnitude of the prolactin surge on oestrous.

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Objective: To assess the temperature variation in the cervical, middle and apical thirds of root external wall, caused by 980-nm diode laser irradiation with different parameters. Methods: The roots of 90 canines, had their canals instrumented and were randomly distributed into 3 groups (n = 30) according to the laser potency (1.5 W, 3.0 W and 5.0 W). Each group was subdivided into 3 (n = 10) according to the frequency (CM, 100 Hz and 1000 Hz), and each subgroup divided into 2 (n = S): dried canal or filled with distilled water. The maximum temperature values were collected by 3 thermocouples located at each third of the root external wall and recorded by digital thermometers. Results: The groups irradiated in the continuous mode (CM) presented the highest values (11.82 +/- 5.78), regardless of the canals were dry or not, which were statistically different (p < 0.01) from those obtained with 100 Hz (6.22 +/- 3.64) and 1000 Hz (6.00 +/- 3.36), which presented no statistical difference between them (p > 0.01). The groups irradiated with 5.0 W presented the greatest temperature variation (12.15 +/- 5.14), followed by 3.0 W (7.88 +/- 3.92) and 1.5 W (4.02 +/- 2.16), differing between them (p < 0.01). The cervical third of the root presented the highest temperature rises (9.68 +/- 5.80), followed by the middle (7.66 +/- 4.87) and apical (6.70 +/- 4.23), with statistical difference among them (p < 0.01). After 30 s from the end of irradiation, all the specimens presented temperature variation lower than 10 degrees C. Conclusions: Application of 980-nm diode laser in the root, at 1.5 W in all operating modes, and 3.0 W, in the pulsed mode, for 20 s, can safely be used in endodontic treatment, irrespective of the presence of humidity. (C) 2008 Elsevier Ltd. All rights reserved.

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The seasonal distribution of Lutzomyia longipalpis was studied in two forested and five domiciliary areas of the urban area of Campo Grande; MS, from December 2003 to November 2005. Weekly captures were carried out with CDC light traps positioned on ground and in the canopy inside a residual forest and on the edge (ground) of a woodland and in at least one of the following ecotopes in peridomiciles-a cultivated area, a chicken coop, a pigsty, a kennel, a goat and sheep shelter and an intradomicile. A total of 9519 sand flies were collected, 2666 during the first year and 6853 during the second. L. longipalpis was found throughout the 2-year period, presenting smaller peaks at intervals of 2-3 months and two greater peaks, the first in February and the second in April 2005, soon after periods of heavy rain. Only In one of the woodlands was a significant negative correlation (p < 0.05) between the number of insects and temperature during the first year and the climatic factors (temperature, RHA and rain) was observed. In the domiciliary areas in four domiciles some positive correlations (p < 0.05) occurred in relation to one or more climatic factors; however, the species shows a clear tendency to greater frequency (72%) in the rainy season than in the dry (28%). Thus, we recommend an intensification of the VL control measures applied in Campo Grande, MS, during the rainy season with a view to reducing the risk of the transmission of the disease. (C) 2007 Elsevier B.V. All fights reserved.

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Studies of wide-band tracheids (WBTs) have aroused the interest of researchers who have searched to understand their origin, function, and phylogenetic implications. The present research has the objective of studying the distribution of WBTs, together with anatomic aspects of vegetative organs in different stages of Pilosocereus aurisetus, in order to understand the occurrence of WBTs in columnar cacti. Transverse and longitudinal sections of the stem (apex, middle, and base) and the root were made. The epidermis was present in the photosynthetic stem, but was substituted by periderm which was already well established in the root. The differentiation of the cortex is visible in the middle of the stem, becoming homogeneous in the base. WBTs were observed in the base and middle of young stems (WBT monomorphic wood); common in stems of globular cacti. However, WBTs/ fibrous dimorphic wood was observed in the base of adult stems, a result of the cambial activity producing vessel elements and fibers. This wood polymorphism of the Cactaceae can be interpreted as cambial variation, a common character of Caryophyllales. Due to the small size of the plant, the presence of WBTs in the young stem may be related to water retention necessary for its development, rather than to physical support of the plant.

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Background and Aims Several animals that live on bromeliads can contribute to plant nutrition through nitrogen provisioning (digestive mutualism). The bromeliad-living spider Psecas chapoda (Salticidae) inhabits and breeds on Bromelia balansae in regions of South America, but in specific regions can also appear on Ananas comosus (pineapple) plantations and Aechmea distichantha. Methods Using isotopic and physiological methods in greenhouse experiments, the role of labelled ((15)N) spider faeces and Drosophila melanogaster flies in the nutrition and growth of each host plant was evaluated, as well as seasonal variation in the importance of this digestive mutualism. Key Results Spiders contributed 0.6 +/- 0.2% (mean +/- s.e.; dry season) to 2.7 +/- 1% (wet season) to the total nitrogen in B. balansae, 2.4 +/- 0.4% (dry) to 4.1 +/- 0.3% (wet) in An. comosus and 3.8 +/- 0.4% (dry) to 5 +/- 1% (wet) in Ae. distichantha. In contrast, flies did not contribute to the nutrition of these bromeliads. Chlorophylls and carotenoid concentrations did not differ among treatments. Plants that received faeces had higher soluble protein concentrations and leaf growth (RGR) only during the wet season. Conclusions These results indicate that the mutualism between spiders and bromeliads is seasonally restricted, generating a conditional outcome. There was interspecific variation in nutrient uptake, probably related to each species` performance and photosynthetic pathways. Whereas B. balansae seems to use nitrogen for growth, Ae. distichantha apparently stores nitrogen for stressful nutritional conditions. Bromeliads absorbed more nitrogen coming from spider faeces than from flies, reinforcing the beneficial role played by predators in these digestive mutualisms.