970 resultados para POPULATION PROBLEMS


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Background: There is a paucity of information describing the real-time 3-dimensional echocardiography (RT3DE) and dyssynchrony indexes (DIs) of a normal population. We evaluate the RT3DE DIs in a population with normal electrocardiograms and 2- and 3-dimensional echocardiographic analyses. This information is relevant for cardiac resynchronization therapy. Methods: We evaluated 131 healthy volunteers (73 were male, aged 46 +/- 14 years) who were referred for routine echocardiography; who presented normal cardiac structure on electrocardiography, 2-dimensional echocardiography, and RT3DE; and who had no history of cardiac diseases. We analyzed 3-dimensional left ventricular ejection fraction, left ventricle end-diastolic volume, left ventricle end-systolic volume, and left ventricular systolic DI% (6-, 12-, and 16-segment models). RT3DE data were analyzed by quantifying the statistical distribution (mean, median, standard deviation [SD], relative SD, coefficient of skewness, coefficient of kurtosis, Kolmogorov-Smirnov test, D`Agostino-Pearson test, percentiles, and 95% confidence interval). Results: Left ventricular ejection fraction ranged from 50% to 80% (66.1% +/- 7.1%); left ventricle end-diastolic volume ranged from 39.8 to 145 mL (79.1 +/- 24.9 mL); left ventricle end-systolic volume ranged from 12.9 to 66 mL (27 +/- 12.1 mL); 6-segment DI% ranged from 0.20% to 3.80% (1.21% +/- 0.66%), median: 1.06, relative SD: 0.5482, coefficient of skewness: 1.2620 (P < .0001), coefficient of Kurtosis: 1.9956 (P = .0039); percentile 2.5%: 0.2900, percentile 97.5%: 2.8300; 12-segment DI% ranged from 0.22% to 4.01% (1.29% +/- 0.71%), median: 1.14, relative SD: 0.95, coefficient of skewness: 1.1089 (P < .0001), coefficient of Kurtosis: 1.6372 (P = .0100), percentile 2.5%: 0.2850, percentile 97.5%: 3.0700; and 16-segment DI% ranged from 0.29% to 4.88% (1.59 +/- 0.99), median: 1.39, relative SD: 0.56, coefficient of skewness: 1.0792 (P < .0001), coefficient of Kurtosis: 0.9248 (P = .07), percentile 2.5%: 0.3750, percentile 97.5%: 3.750. Conclusion: This study allows for the quantification of RT3DE DIs in normal subjects, providing a comparison for patients with heart failure who may be candidates for cardiac resynchronization therapy. (J Am Soc Echocardiogr 2008; 21: 1229-1235)

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Objective: To investigate: 1) the impact of clinical varicocele on reactive oxygen species (ROS) levels in neat and washed semen in a proven fertile population; and 2) the correlation between ROS levels, testicular volume, and varicocele grade in the same population of fertile men. Design: Prospective controlled clinical study. Setting: Andrology laboratory at tertiary-care hospital. Patient(s): One hundred fourteen healthy fertile men (81 normal fertile and 33 fertile with clinical varicocele) and 30 infertile patients (control subjects). Intervention(s): Standard semen analysis and measurement of sperm ROS production. Main Outcome Measure(s): Seminal parameters, seminal ROS levels, seminal leukocyte levels, clinical varicocele, and testis size. Result(s): Thirty-three of the 11.4 (29%) fertile men had clinical varicocele (grade 1, n = 14; grade 2, n = 11; and grade 3, n = 8), and the remaining 81 (71%) had a normal physical examination. Levels of ROS and semen quality did not differ significantly between the fertile men with or without varicocele. No significant differences in ROS levels in neat and washed semen were observed compared with fertile men with grades 2 and 3 varicocele and with fertile men with varicocele grade 1. The ROS levels in neat and washed semen were not significantly correlated with varicocele grade in fertile men. No significant correlations between ROS levels and testis volume were observed between the fertile groups. Conclusion(s): The presence of clinical varicocele in fertile men is not associated with higher seminal ROS levels or abnormal semen parameters. Levels of ROS are not correlated with varicocele grade or testis volume in the same population of fertile men.

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Problem We evaluated associations between a length polymorphism in intron 2 of the gene coding for IL-1ra (gene symbol IL1RN) and pregnancy outcome in a population with a high rate of preterm birth. Method of study Subjects were pregnant women in Maceio, Brazil and their newborns. DNA was tested for IL1RN genotypes and alleles by gene amplification using primer pairs that spanned the polymorphic region. Every subject completed a detailed questionnaire. Results The frequency of allele 2 (IL1RN*2) carriage was elevated in mothers with a spontaneous preterm birth (SPTB) in the current pregnancy (P = 0.02) and also with a prior preterm delivery (P = .01). Both SPTB with intact membranes (P = 0.01) and SPTB preceded by pre-term pre-mature rupture of membranes (P = .03) were associated with IL1RN*2 carriage. A previous fetal demise was more than twice as prevalent in mothers positive for two copies of IL1RN*2. Conclusion Maternal carriage of IL1RN*2 increases susceptibility to inflammation-triggered spontaneous pre-term birth.

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Background In the World Health Organization book by Murray and Lopez (The Global Burden of Disease), the authors make the point that there are major regional differences across the world for death from injury. In the European market economies, injuries accounted for 6% of all deaths, of which the majority were the result of road traffic accidents. In stark contrast, in Latin America and the Caribbean, injuries account for 12-13% of all deaths, and most of these are the result of violence. An estimated 30% of all male deaths are from external causes, and road traffic accidents are the number two cause of death. Within South American countries, trauma is the second most common cause of death in Columbia, Venezuela, Ecuador, and Brazil. In other South American countries, it is the third or fourth most common cause of death. If one examines the Disability Adjusted Life Years, South America is the third highest in the world. Death from injury primarily affects people in the middle- and low-income group. Traffic accidents and suicide are the main causes of trauma in the high-income population. South America is made up of developing and poor countries that have trauma as a very important cause of death and disability. Methods The author has reviewed information on injury from the World Health Organization, Pan American Health Organization, and Brazilian Health Ministry. In addition, a search of injury was performed through MEDLINE. Results and Conclusions The results of this review show that trauma is a major public health problem in South America. At the present time, there is a lack of statewide system development. In addition, there are difficulties in training surgeons to cope with these problems.

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Stickiness is a major reason that limits the spray drying of various sugar-rich food products. Higher hygroscopicity of amorphous powder, increase in solubility of sugars with temperature, and lower melting point and glass transition temperature, contribute to the stickiness problem. So far, the glass transition temperature has been widely accepted as a best indicator for stickiness. There are various manoeuvres that have been applied to spray dry such products. Some of them are the addition of drying aids, modification of drier design and use of mild drying temperature conditions. This review paper highlights the major research works that deal with the stickiness property of sugar-rich foods.

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Neutron activation analysis was applied to assess trace elements concentrations in head hair from healthy elderly people living in the Sao Paulo metropolitan area. Concentrations of As, Br, Ca, Cl, Co, Cr, Cu, Fe, K, La, Mn, Na, Sb, Se and, Zn were determined. Comparisons were made between the results obtained for dyed and non-dyed hair as well as for hair from females and males of two different age groups. The results were also compared with range values established by clinical laboratories and published data.

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Genetic population structure in the catadromous Australian bass Macquaria novemaculeata was investigated using samples from four locations spanning 600 km along the eastern Australian coastline. Both allozymes and mtDNA control region sequences were examined. Population subdivision estimates based on allozymes revealed low levels of population structuring (G(st)=0.043, P<0.05). However, mtDNA indicated moderate levels of geographic population structure (G(st)=0.146, P<0.01). Phylogenetic analysis of mtDNA control region sequences (mean sequence divergence 1.9%) indicated little phylogeographic structuring. Results suggested that genotypic variation within each river population, while bring affected primarily by genetic drift, was also prevented from more significant divergence by homogenizing levels of gene flow-synonymous with a one-dimensional stepping-stone model of population structure. The catadromous life history of Macquaria novemaculeata was considered to br influential on the pattern of population structure displayed. Results were compared to the few population genetic studies involving catadromous fishes, indicating that catadromy alone is unlikely to be a good predictor of population structure. A more comprehensive suite of biological characteristics than simple life-history traits must be considered fully to allow reliable predictive models of population structure to be formulated. (C) 1997 The Fisheries Society of the British Isles.

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Social surveys have established dose-response relationships between aircraft noise and annoyance, with a number of psychological symptoms being positively related to annoyance. Evidence that exposure to aircraft noise is associated with higher psychiatric hospital admission rates is mixed. Some evidence exists of an association between aircraft noise exposure and use of psychotropic medications. People with a pre-existing psychological or psychiatric condition may be more susceptible to the effects of exposure to aircraft noise. Aircraft noise can produce effects on electroencephalogram sleep patterns and cause wakefulness and difficulty in sleeping. Attendances at general practitioners, self-reported health problems and use of medications, have been associated with exposure to aircraft noise, but some findings are inconsistent. Some association between aircraft noise exposure and elevated mean blood pressure has been observed in cross-sectional studies of schoolchildren, but with little confirmation from cohort studies. There is no convincing evidence to suggest that all-cause or cause-specific mortality is increased by exposure to aircraft noise. There is no strong evidence that aircraft noise has significant perinatal effects. Using the World Health Organization definition of health, which includes positive mental and social wellbeing, aircraft noise is responsible for considerable ill-health. However, population-based studies have not found strong evidence that people living near or under aircraft flight paths suffer higher rates of clinical morbidity or mortality as a consequence of exposure to aircraft noise. A dearth of high quality studies in this area precludes drawing substantive conclusions.

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The fluorescence spectrum of a strongly driven two-level atom located inside an optical cavity damped by a narrow-bandwidth squeezed vacuum is studied. We use a dressed atom model approach, first applied to squeezed vacuum problems by Yeoman and Barnett, to derive the master equation of the system and discuss the role of the cavity and the squeezed vacuum in the narrowing of the spectral lines and the population trapping effect. We find that in the presence of a single-mode cavity the effect of squeezing on the fluorescence spectrum is more evident in the linewidths of the Rabi sidebands rather than in the linewidth of the central component. Even in the absence of squeezing, the cavity can reduce the linewidth of the central component almost to zero, whereas the Rabi sidebands can be narrowed only to some finite value. In the presence of a two-mode cavity and a two-mode squeezed vacuum the signature of squeezing is evident in the linewidths of all spectral lines. We also establish that the narrowing of the spectral lines is very sensitive to the detuning of the driving field from the atomic resonance. Moreover, we find that the population trapping effect, predicted for the broadband squeezed vacuum case, may appear in a narrow-bandwidth case only if the input squeezed modes are perfectly matched to the cavity modes and if there is non-zero squeezing at the Rabi sidebands.

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Plant transformation is now a core research tool in plant biology and a practical tool for cultivar improvement. There are verified methods for stable introduction of novel genes into the nuclear genomes of over 120 diverse plant species. This review examines the criteria to verify plant transformation; the biological and practical requirements for transformation systems; the integration of tissue culture, gene transfer, selection, and transgene expression strategies to achieve transformation in recalcitrant species; and other constraints to plant transformation including regulatory environment, public perceptions, intellectual property, and economics. Because the costs of screening populations showing diverse genetic changes can far exceed the costs of transformation, it is important to distinguish absolute and useful transformation efficiencies. The major technical challenge facing plant transformation biology is the development of methods and constructs to produce a high proportion of plants showing predictable transgene expression without collateral genetic damage. This will require answers to a series of biological and technical questions, some of which are defined.

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A risk score model was developed based in a population of 1,224 individuals from the general population without known diabetes aging 35 years or more from an urban Brazilian population sample in order to select individuals who should be screened in subsequent testing and improve the efficacy of public health assurance. External validation was performed in a second, independent, population from a different city ascertained through a similar epidemiological protocol. The risk score was developed by multiple logistic regression and model performance and cutoff values were derived from a receiver operating characteristic curve. Model`s capacity of predicting fasting blood glucose levels was tested analyzing data from a 5-year follow-up protocol conducted in the general population. Items independently and significantly associated with diabetes were age, BMI and known hypertension. Sensitivity, specificity and proportion of further testing necessary for the best cutoff value were 75.9, 66.9 and 37.2%, respectively. External validation confirmed the model`s adequacy (AUC equal to 0.72). Finally, model score was also capable of predicting fasting blood glucose progression in non-diabetic individuals in a 5-year follow-up period. In conclusion, this simple diabetes risk score was able to identify individuals with an increased likelihood of having diabetes and it can be used to stratify subpopulations in which performing of subsequent tests is necessary and probably cost-effective.

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Introduction: The metabolic syndrome (MS) is characterized by multiple cardiovascular risk factors such as central obesity, arterial hypertension, dislipidemia and hyperinsulinemia and is associated with a higher incidence of cardiovascular events and mortality. The aim of the present work is to describe the prevalence of MS in an urban population from a highly admixed developing country and to characterize the different correlations between this diagnosis, cardiovascular risk factors and demographic variables distributed in this population. Materials and methods: A cross-sectional study of risk factors for cardiovascular diseases was performed in the urban population of Vitoria, Brazil (n= 1507). Major cardiovascular risk factors such as smoking habits, alcohol intake, amount of physical activity, diabetes and hypertension were inquired. Blood biochemical assays were performed by standard techniques in 12 h fasting blood sample and Metabolic Syndrome (MS) was characterizes following the ATP III criteria. Results: The analysis of 1507 individuals showed a 25.43% general prevalence of MS without any significant difference between sexes, but a clear relation of the prevalence with progressing age (p=<0.0001). Even though both sexes showed similar prevalence rates, distribution of risk factors that defined MS was different between men and women, with the prevalence of hypertension, fasting hyperglycemia and hypertriglyceridemia being higher in men. Race was not an important risk factor for MS in this population as opposed to social economic class that was highly associated with the risk of MS in women as their social class was lower, but not in men. Conclusion: This cross-sectional study from a large urban population in Brazil showed a high general prevalence of MS (25.4%), which is increased as the population becomes older (especially in women) and poorer. Although prevalence was very similar in both genders, the frequency of components defining the syndrome varied greatly amongst them. In particular, a significant interaction between gender and social class was observed and may shed light in our understanding of the complex interplay between demographic and biological risk factors for metabolic syndrome. (C) 2007 Elsevier Ireland Ltd. All rights reserved.