84 resultados para Curves of progress of diseases
Resumo:
The prevention and treatment of diseases related to changes in body composition require accurate methods for the measurement of body composition. However, few studies have dealt specifically with the assessment of body composition of undernourished older subjects by different methodologies. To assess the body composition of undernourished older subjects by two different methods, dual energy x-ray absorptiometry (DXA) and bioelectric impedance (BIA), and to compare results with those of an eutrophic group. The study model was cross-sectional; the study was performed at the University Hospital of the School of Medicine of Ribeiro Preto, University of So Paulo, Brazil. Forty-one male volunteers aged 62 to 91 years. The groups were selected on the basis of anamnesis, physical examination and nutritional assessment according to the Mini Nutritional Assessment (MNA) score. Body composition was assessed by DXA and BIA. Body weight, arm and calf circumference, body mass index (BMI), fat free mass (FFM) and fat mass (FM) were significantly lower in the undernourished group as compared to the eutrophic group. There were no significant differences between FFM and FM mean values determined by DXA and BIA in both groups, but the agreement between methods in the undernourished group was less strong. Our results suggest caution when BIA is to be applied in studies including undernourished older subjects. This study does not support BIA as an accurate method for the individual assessment of body composition.
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Inflammation is a pivotal component of a variety of diseases, such as atherosclerosis and tumour progression. Various naturally occurring phytochemicals exhibit anti-inflammatory activity and are considered to be potential drug candidates against inflammation-related pathological processes. Capsicum baccatum L. var. pendulum (Willd.) Eshbaugh (Solanaceae) is the most consumed species in Brazil, and its compounds, such as capsaicinoids, have been found to inhibit the inflammatory process. However, the anti-inflammatory effects of C. baccatum have not been characterized. Thus, this study was designed to evaluate the effects of C. baccatum juice in animal models of acute inflammation induced by carrageenan and immune inflammation induced by methylated bovine serum albumin. Pretreatment (30 min) of rats with pepper juice (0.25-2.0 g kg(-1)) significantly decreased leucocyte and neutrophil migration, exudate volume and protein and LDH concentration in pleural exudates of a pleurisy model. This juice also inhibited neutrophil migration and reduced the vascular permeability on carrageenan-induced peritonitis in mice. C. baccatum juice also reduced neutrophil recruitment and exudate levels of pro-inflammatory cytokines TNF-alpha, and IL-1 beta in mouse inflammatory immune peritonitis. Furthermore, we demonstrated that the main constituent of C. baccatum juice, as extracted with chloroform, is capsaicin. In agreement with this, capsaicin was able to inhibit the neutrophil migration towards the inflammatory focus. To our knowledge, this is the first demonstration of the anti-inflammatory effect of C. baccatum juice and our data suggest that this effect may be induced by capsaicin. Moreover, the anti-inflammatory effect induced by red pepper may be by inhibition of pro-inflammatory cytokine production at the inflammatory site.
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This work aims to compare different nonlinear functions for describing the growth curves of Nelore females. The growth curve parameters, their (co) variance components, and environmental and genetic effects were estimated jointly through a Bayesian hierarchical model. In the first stage of the hierarchy, 4 nonlinear functions were compared: Brody, Von Bertalanffy, Gompertz, and logistic. The analyses were carried out using 3 different data sets to check goodness of fit while having animals with few records. Three different assumptions about SD of fitting errors were considered: constancy throughout the trajectory, linear increasing until 3 yr of age and constancy thereafter, and variation following the nonlinear function applied in the first stage of the hierarchy. Comparisons of the overall goodness of fit were based on Akaike information criterion, the Bayesian information criterion, and the deviance information criterion. Goodness of fit at different points of the growth curve was compared applying the Gelfand`s check function. The posterior means of adult BW ranged from 531.78 to 586.89 kg. Greater estimates of adult BW were observed when the fitting error variance was considered constant along the trajectory. The models were not suitable to describe the SD of fitting errors at the beginning of the growth curve. All functions provided less accurate predictions at the beginning of growth, and predictions were more accurate after 48 mo of age. The prediction of adult BW using nonlinear functions can be accurate when growth curve parameters and their (co) variance components are estimated jointly. The hierarchical model used in the present study can be applied to the prediction of mature BW in herds in which a portion of the animals are culled before adult age. Gompertz, Von Bertalanffy, and Brody functions were adequate to establish mean growth patterns and to predict the adult BW of Nelore females. The Brody model was more accurate in predicting the birth weight of these animals and presented the best overall goodness of fit.
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Background Microalbuminuria and hypertension have long been associated with a guarded prognosis in human patients with a variety of diseases. In veterinary medicine, tests for microalbuminuria have been used for detecting early kidney damage, but there is little information regarding its association with high blood pressure in dogs with chronic kidney disease (CKD). Objective The objective of this study was to evaluate albuminuria and its association with arterial hypertension in dogs with CKD. Methods Urinary albumin:creatinine (UAC) ratio, urinary protein:creatinine (UPC) ratio, and systolic blood pressure were determined in 39 clinically healthy dogs and 40 dogs with CKD. Results UAC in dogs with CKD (range, 0.002-7.99; median, 0.38) was statistically different from that of control dogs (range, 0.0005-0.01; median, 0.002). Microalbuminuria (UAC 0.03-0.3) and macroalbuminuria (UAC > 0.3) were detected in 32.5% and 50% of dogs with CKD, respectively. Sixty percent (24/40) of dogs with CKD had systolic pressure >= 180 mmHg; in these dogs, UAC ratio (range, 0.006-7.99; median, 1.72) was significantly higher than in dogs with CKD and systolic pressure < 180 mmHg (range, 0.002-4.83; median, 0.10). Of hypertensive dogs with CKD, those with UPC > 1.0 usually had macroalbuminuria, those with UPC 0.5-1.0 usually had microalbuminuria, and those with UPC < 0.5 usually lacked albuminuria. Conclusions UAC ratio was higher in hypertensive than in normotensive dogs with CKD. Tests designed to detect microalbuminuria may be useful for hypertensive dogs with CKD and a UPC < 1.0 to detect the onset and magnitude of albuminuria. Once macroalbuminuria is overt, the UPC ratio itself can be used for the same purpose.
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Background The objectives were to estimate the prevalence of hepatitis A among children and adolescents from the Northeast and Midwest regions and the Federal District of Brazil and to identify individual-, household- and area-levels factors associated with hepatitis A infection. Methods This population-based survey was conducted in 20042005 and covered individuals aged between 5 and 19 years. A stratified multistage cluster sampling technique with probability proportional to size was used to select 1937 individuals aged between 5 and 19 years living in the Federal capital and in the State capitals of 12 states in the study regions. The sample was stratified according to age (59 and 10- to 19-years-old) and capital within each region. Individual- and household-level data were collected by interview at the home of the individual. Variables related to the area were retrieved from census tract data. The outcome was total antibodies to hepatitis A virus detected using commercial EIA. The age distribution of the susceptible population was estimated using a simple catalytic model. The associations between HAV infection and independent variables were assessed using the odds ratio and corrected for the random design effect and sampling weight. Multilevel analysis was performed by GLLAMM using Stata 9.2. Results The prevalence of hepatitis A infection in the 59 and 1019 age-group was 41.5 and 57.4, respectively for the Northeast, 32.3 and 56.0, respectively for the Midwest and 33.8 and 65.1 for the Federal District. A trend for the prevalence of HAV infection to increase according to age was detected in all sites. By the age of 5, 31.5 of the children had already been infected with HAV in the Northeast region compared with 20.0 in the other sites. By the age of 19 years, seropositivity was 70 in all areas. The curves of susceptible populations differed from one area to another. Multilevel modeling showed that variables relating to different levels of education were associated with HAV infection in all sites. Conclusion The study sites were classified as areas with intermediate endemicity area for hepatitis A infection. Differences in age trends of infection were detected among settings. This multilevel model allowed for quantification of contextual predictors of hepatitis A infection in urban areas.
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Objectives. To assess the impact of chronic disease and the number of diseases on the various aspects of health-related quality of life (HRQOL) among the elderly in Sao Paulo, Brazil. Methods. The SF-36 (R) Health Survey was used to assess the impact of the most prevalent chronic diseases on HRQOL. A cross-sectional and population-based study was carried out with two-stage stratified cluster sampling. Data were obtained from a multicenter health survey administered through household interviews in several municipalities in the state of Sao Paulo. The study evaluated seven diseases-arthritis, back-pain, depression/anxiety, diabetes, hypertension, osteoporosis, and stroke-and their effects on quality of life. Results. Among the 1958 elderly individuals (60 years of age or older), 13.6% reported not having any of the illnesses, whereas 45.7% presented three or more chronic conditions. The presence of any of the seven chronic illnesses studied had a significant effect on the scores Of nearly all the SF-36 (R) scales. HRQOL achieved lower scores when related to depression/anxiety, osteoporosis, and stroke. The higher the number of diseases, the greater the negative effect on the SF-36 (R) dimensions. The presence of three or more diseases significantly affected HRQOL in all areas. The bodily pain, general health, and vitality scales were the most affected by diseases. Conclusions. The study detected a high prevalence of chronic diseases among the elderly population and found that the degree of impact on HRQOL depends on the type of disease. The results highlight the importance of preventing and controlling chronic diseases in order to reduce the number of comorbidities and lessen their impact on HRQOL among the elderly.
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Ozone dynamics depend on meteorological characteristics such as wind, radiation, sunshine, air temperature and precipitation. The aim of this study was to determine ozone trajectories along the northern coast of Portugal during the summer months of 2005, when there was a spate of forest fires in the region, evaluating their impact on respiratory and cardiovascular health in the greater metropolitan area of Porto. We investigated the following diseases, as coded in the ninth revision of the International Classification of Diseases: hypertensive disease (codes 401-405); ischemic heart disease (codes 410-414); other cardiac diseases, including heart failure (codes 426-428); chronic obstructive pulmonary disease and allied conditions, including bronchitis and asthma (codes 490-496); and pneumoconiosis and other lung diseases due to external agents (codes 500-507). We evaluated ozone data from air quality monitoring stations in the study area, together with data collected through HYbrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model analysis of air mass circulation and synoptic-scale zonal wind from National Centers for Environmental Prediction data. High ozone levels in rural areas were attributed to the dispersion of pollutants induced by local circulation, as well as by mesoscale and synoptic scale processes. The fires of 2005 increased the levels of pollutants resulting from the direct emission of gases and particles into the atmosphere, especially when there were incoming frontal systems. For the meteorological case studies analyzed, peaks in ozone concentration were positively associated with higher rates of hospital admissions for cardiovascular diseases, although there were no significant associations between ozone peaks and admissions for respiratory diseases.
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We report the analysis of a uniform sample of 31 light curves of the nova-like variable UU Aqr with eclipse-mapping techniques. The data were combined to derive eclipse maps of the average steady-light component, the long-term brightness changes, and the low- and high-frequency flickering components. The long-term variability responsible for the ""low-brightness`` and ""high-brightness`` states is explained in terms of the response of a viscous disk to changes of 20%-50% in the mass transfer rate from the donor star. Low- and high-frequency flickering maps are dominated by emission from two asymmetric arcs reminiscent of those seen in the outbursting dwarf nova IP Peg, and they are similarly interpreted as manifestations of a tidally induced spiral shock wave in the outer regions of a large accretion disk. The asymmetric arcs are also seen in the map of the steady light aside from the broad brightness distribution of a roughly steady-state disk. The arcs account for 25% of the steady-light flux and are a long-lasting feature in the accretion disk of UU Aqr. We infer an opening angle of 10 degrees +/- 3 degrees for the spiral arcs. The results suggest that the flickering in UU Aqr is caused by turbulence generated after the collision of disk gas with the density-enhanced spiral wave in the accretion disk.
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Leishmania spp. are the causative agents of leishmaniasis, a complex of diseases with a broad spectrum of clinical manifestations. Leishmania (Leishmania) amazonensis is a main etiological agent of diffuse cutaneous leishmaniasis. Leishmania spp., as other trypanosomatids, possess a metabolism based significantly on the consumption of amino acids. However, the transport of amino acids in these organisms remains poorly understood with few exceptions. Glutamate transport is an important biological process in many organisms. In the present work, the transport of glutamate is characterized. This process is performed by a single kinetic system (K-m=0.59 +/- 0.04 mM, V-max=0.123 +/- 0.003 nmol/min per 20 x 10(6) cells) showing an energy of activation of 52.38 +/- 4.7 kJ/mol and was shown to be partially inhibited by analogues, such as glutamine, aspartate, alpha-ketoglutarate and oxaloacetate, methionine, and alanine. The transport activity was sensitive to the extracellular concentration of H+ but not to Na+ or K+. However, unlike other amino acid transporters presently characterized, the treatment with specific ionophores confirmed the participation of a K+, and not H+ membrane gradient in the transport process.
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Some dosimetric properties of watch glasses were studied applying the thermoluminescence technique. The watch glass samples were powdered, and the selected grains were mixed with Teflon (TM). The mixture was pressed and sintered to produce pellets of watch glass-Teflon (TM) composites. The glow curves of the pellets show two peaks at 130 and 195 degrees C. Reproducibility of TL response was estimated to have a maximum coefficient of variation of 4.0%. The dose-response curve is sublinear between 0.5 and 20.0kGy. The calibration curve is linear between 1.0Gy and 1.0kGy. The minimum detection limits were also determined. The gamma radiation dose response and the thermal stability of the materials were studied with the purpose to establish the best conditions of watch glasses for use in gamma radiation dosimetry. (C) 2007 Elsevier Ltd. All rights reserved.
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The quality control optimization of medical processes that use ionizing radiation in the treatment of diseases like cancer is a key element for patient safety and success of treatment. The major medical application of radiation is radiotherapy, i.e. the delivery of dose levels to well-defined target tissues of a patient with the purpose of eliminating a disease. The need of an accurate tumour-edge definition with the purpose of preserving healthy surrounding tissue demands rigorous radiation treatment planning. Dosimetric methods are used for dose distribution mapping region of interest to assure that the prescribed dose and the irradiated region are correct. The Fricke gel (FXG) is the main dosimeter that supplies visualization of the three-dimensional (3D) dose distribution. In this work the dosimetric characteristics of the modified Fricke dosimeter produced at the Radiation Metrology Centre of the Institute of Energetic and Nuclear Research (IPEN) such as gel concentration dose response dependence, xylenol orange addition influence, dose response between 5 and 50Gy and signal stability were evaluated by magnetic resonance imaging (MRI). Using the same gel solution, breast simulators (phantoms) were shaped and absorbed dose distributions were imaged by MRI at the Nuclear Resonance Laboratory of the Physics Institute of Sao Paulo University. (C) 2007 Elsevier Ltd. All rights reserved.
Resumo:
Samples of natural andalusite (Al(2)SiO(5)) crystal have been investigated in terms of thermoluminescence (TL) and electron paramagnetic resonance (EPR) measurements. The TL glow curves of samples previously annealed at 600 degrees C for 30 min and subsequently gamma-irradiated gave rise to four glow peaks at 150, 210, 280 and 350 degrees C. The EPR spectra of natural samples heat-treated at 600 degrees C for 30 min show signals at g = 5.94 and 2.014 that do not change after gamma irradiation and thermal treatments. However, it was observed that the appearance of a paramagnetic center at g=1.882 for the samples annealed at 600 degrees C for 30 min followed gamma irradiation. This line was attributed to Ti(3+) centers. The EPR signals observed at g=5.94 and 2.014 are due to Fe(3+). Correlations between EPR and TL results of these crystals show that the EPR line at g=1.882 and the TL peak at 280 degrees C can be attributed to the same defect center. (C) 2011 Elsevier B.V. All rights reserved.
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The adsorption kinetics curves of poly(xylylidene tetrahydrothiophenium chloride) (PTHT), a poly-p-phenylenevinylene (PPV) precursor, and the sodium salt of dodecylbenzene sulfonic acid (DBS), onto (PTHT/DBS)(n) layer-by-layer (LBL) films were characterized by means of UV-vis spectroscopy. The amount of PTHT/DBS and PTHT adsorbed on each layer was shown to be practically independent of adsorption time. A Langmuir-type metastable equilibrium model was used to adjust the adsorption isotherms data and to estimate adsorption/desorption coefficients ratios, k = k(ads)/k(des), values of 2 x 10(5) and 4 x 10(6) for PTHT and PTHT/DBS layers, respectively. The desorption coefficient has been estimated, using literature values for poly(o-methoxyaniline) desorption coefficient, as was found to be in the range of 10(-9) to 10(-6) s(-1), indicating that quasi equilibrium is rapidly attained.
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The thermoluminescence (TL) characteristics of quartz are highly dependent of its thermal history. Based on the enhancement of quartz luminescence occurred after heating, some authors proposed to use quartz TL to recover thermal events that affected quartz crystals. However, little is know about the influence of the temperature of quartz crystallization on its TL characteristics. In the present study, we evaluate the TL sensitivity and dose response curves of hydrothermal and metamorphic quartz with crystallization temperatures from 209 +/- 15 to 633 +/- 27 degrees C determined through fluid inclusion and mineral chemistry analysis. The studied crystals present a cooling thermal history, which allow the acquiring of their natural TL without influence of heating after crystallization. The TL curves of the studied samples present two main components formed by different peaks overlapped around 110 C and 200-400 degrees C. The TL sensitivity in the 200-400 degrees C region increases linearly with the temperature of quartz crystallization. No relationship was observed between temperatures of quartz crystallization and saturation doses (<100 Gy). The elevated TL sensitivity of the high temperature quartz is attributed to the control exerted by the temperature of crystallization on the substitution of Si(4+) by ions such as Al(3+) and Ti(4+), which produce defects responsible for luminescence phenomena. The linear relationship observed between TL in the 200-400 degrees C region and crystallization temperature has potential use as a quartz geothermometer. The relative abundance of quartz in the earth crust and the easiness to measure TL are advantageous in relation to geothermometry methods based on chemistry of other minerals. (C) 2010 Elsevier Ltd. All rights reserved.
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This paper is concerned with the existence and nonlinear stability of periodic travelling-wave solutions for a nonlinear Schrodinger-type system arising in nonlinear optics. We show the existence of smooth curves of periodic solutions depending on the dnoidal-type functions. We prove stability results by perturbations having the same minimal wavelength, and instability behaviour by perturbations of two or more times the minima period. We also establish global well posedness for our system by using Bourgain`s approach.