775 resultados para low risk population
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We propose first, a simple task for the eliciting attitudes toward risky choice, the SGG lottery-panel task, which consists in a series of lotteries constructed to compensate riskier options with higher risk-return trade-offs. Using Principal Component Analysis technique, we show that the SGG lottery-panel task is capable of capturing two dimensions of individual risky decision making i.e. subjects’ average risk taking and their sensitivity towards variations in risk-return. From the results of a large experimental dataset, we confirm that the task systematically captures a number of regularities such as: A tendency to risk averse behavior (only around 10% of choices are compatible with risk neutrality); An attraction to certain payoffs compared to low risk lotteries, compatible with over-(under-) weighting of small (large) probabilities predicted in PT and; Gender differences, i.e. males being consistently less risk averse than females but both genders being similarly responsive to the increases in risk-premium. Another interesting result is that in hypothetical choices most individuals increase their risk taking responding to the increase in return to risk, as predicted by PT, while across panels with real rewards we see even more changes, but opposite to the expected pattern of riskier choices for higher risk-returns. Therefore, we conclude from our data that an “economic anomaly” emerges in the real reward choices opposite to the hypothetical choices. These findings are in line with Camerer's (1995) view that although in many domains, paid subjects probably do exert extra mental effort which improves their performance, choice over money gambles is not likely to be a domain in which effort will improve adherence to rational axioms (p. 635). Finally, we demonstrate that both dimensions of risk attitudes, average risk taking and sensitivity towards variations in the return to risk, are desirable not only to describe behavior under risk but also to explain behavior in other contexts, as illustrated by an example. In the second study, we propose three additional treatments intended to elicit risk attitudes under high stakes and mixed outcome (gains and losses) lotteries. Using a dataset obtained from a hypothetical implementation of the tasks we show that the new treatments are able to capture both dimensions of risk attitudes. This new dataset allows us to describe several regularities, both at the aggregate and within-subjects level. We find that in every treatment over 70% of choices show some degree of risk aversion and only between 0.6% and 15.3% of individuals are consistently risk neutral within the same treatment. We also confirm the existence of gender differences in the degree of risk taking, that is, in all treatments females prefer safer lotteries compared to males. Regarding our second dimension of risk attitudes we observe, in all treatments, an increase in risk taking in response to risk premium increases. Treatment comparisons reveal other regularities, such as a lower degree of risk taking in large stake treatments compared to low stake treatments and a lower degree of risk taking when losses are incorporated into the large stake lotteries. Results that are compatible with previous findings in the literature, for stake size effects (e.g., Binswanger, 1980; Antoni Bosch-Domènech & Silvestre, 1999; Hogarth & Einhorn, 1990; Holt & Laury, 2002; Kachelmeier & Shehata, 1992; Kühberger et al., 1999; B. J. Weber & Chapman, 2005; Wik et al., 2007) and domain effect (e.g., Brooks and Zank, 2005, Schoemaker, 1990, Wik et al., 2007). Whereas for small stake treatments, we find that the effect of incorporating losses into the outcomes is not so clear. At the aggregate level an increase in risk taking is observed, but also more dispersion in the choices, whilst at the within-subjects level the effect weakens. Finally, regarding responses to risk premium, we find that compared to only gains treatments sensitivity is lower in the mixed lotteries treatments (SL and LL). In general sensitivity to risk-return is more affected by the domain than the stake size. After having described the properties of risk attitudes as captured by the SGG risk elicitation task and its three new versions, it is important to recall that the danger of using unidimensional descriptions of risk attitudes goes beyond the incompatibility with modern economic theories like PT, CPT etc., all of which call for tests with multiple degrees of freedom. Being faithful to this recommendation, the contribution of this essay is an empirically and endogenously determined bi-dimensional specification of risk attitudes, useful to describe behavior under uncertainty and to explain behavior in other contexts. Hopefully, this will contribute to create large datasets containing a multidimensional description of individual risk attitudes, while at the same time allowing for a robust context, compatible with present and even future more complex descriptions of human attitudes towards risk.
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Cocoa flavanol (CF) intake improves endothelial function in patients with cardiovascular risk factors and disease. We investigated the effects of CF on surrogate markers of cardiovascular health in low risk, healthy, middle-aged individuals without history, signs or symptoms of CVD. In a 1-month, open-label, one-armed pilot study, bi-daily ingestion of 450 mg of CF led to a time-dependent increase in endothelial function (measured as flow-mediated vasodilation (FMD)) that plateaued after 2 weeks. Subsequently, in a randomised, controlled, double-masked, parallel-group dietary intervention trial (Clinicaltrials.gov: NCT01799005), 100 healthy, middle-aged (35–60 years) men and women consumed either the CF-containing drink (450 mg) or a nutrient-matched CF-free control bi-daily for 1 month. The primary end point was FMD. Secondary end points included plasma lipids and blood pressure, thus enabling the calculation of Framingham Risk Scores and pulse wave velocity. At 1 month, CF increased FMD over control by 1·2 % (95 % CI 1·0, 1·4 %). CF decreased systolic and diastolic blood pressure by 4·4 mmHg (95 % CI 7·9, 0·9 mmHg) and 3·9 mmHg (95 % CI 6·7, 0·9 mmHg), pulse wave velocity by 0·4 m/s (95 % CI 0·8, 0·04 m/s), total cholesterol by 0·20 mmol/l (95 % CI 0·39, 0·01 mmol/l) and LDL-cholesterol by 0·17 mmol/l (95 % CI 0·32, 0·02 mmol/l), whereas HDL-cholesterol increased by 0·10 mmol/l (95 % CI 0·04, 0·17 mmol/l). By applying the Framingham Risk Score, CF predicted a significant lowering of 10-year risk for CHD, myocardial infarction, CVD, death from CHD and CVD. In healthy individuals, regular CF intake improved accredited cardiovascular surrogates of cardiovascular risk, demonstrating that dietary flavanols have the potential to maintain cardiovascular health even in low-risk subjects.
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Dystrophin, the product of the Duchenne muscular dystrophy (DMD) gene, was studied in muscle from 16 human fetuses at risk for the disease. Eleven high risk (greater than 95% probability) and 5 low-risk (less than 25% probability) fetuses were studied with antibodies raised to different regions of the protein. All low-risk fetuses showed a similar pattern to that of normal fetuses of a comparable age: using Western blot analysis, a protein was detected of similar size and abundance to that of normal fetuses (i.e. smaller molecular weight than that of adult muscle); immunocytochemistry showed uniform sarcolemmal staining in fetuses older than 18 weeks gestation and differential staining of myotubes at different stages of development (distinguished by size) in younger fetuses (less than 15 weeks gestation). In contrast, Western blot analysis of high-risk fetuses detected low levels of dystrophin in 4 cases; 7 fetuses had no detectable protein. Immunocytochemistry with some dystrophin antibodies showed weak staining of the sarcolemma and around central nuclei in younger fetuses; in older fetuses there was little sarcolemmal staining with any antibody other than occasional positive fibres. These results indicate that careful study of dystrophin in fetuses at risk for DMD can be used to establish the clinical phenotype and provide additional information for future family counselling.
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The potential impact of the abrupt 8.2 ka cold event on human demography, settlement patterns and culture in Europe and the Near East has emerged as a key theme in current discussion and debate. We test whether this event had an impact on the Mesolithic population of western Scotland, a case study located within the North Atlantic region where the environmental impact of the 8.2 ka event is likely to have been the most severe. By undertaking a Bayesian analysis of the radiocarbon record and using the number of activity events as a proxy for the size of the human population, we find evidence for a dramatic reduction in the Mesolithic population synchronous with the 8.2 ka event. We interpret this as reflecting the demographic collapse of a low density population that lacked the capability to adapt to the rapid onset of new environmental conditions. This impact of the 8.2 ka event in the North Atlantic region lends credence to the possibility of a similar impact on populations in Continental Europe and the Near East.
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Aim: The objective of this study is to assess the contribution of ADIPOQ variants to type 2 diabetes in Japanese Brazilians. Methods: We genotyped 200 patients with diabetes mellitus (100 male and 100 female, aged 55.0 years [47.5-64.0 years]) and 200 control subjects with normal glucose tolerant (NGT) (72 male and 128 female, aged 52.0 years [43.5-64.5 years]). Results: Whereas each polymorphism studied (T45G, G276T, and A349G) was not significantly associated with type 2 diabetes mellitus, the haplotype GGA was overrepresented in our diabetic population (9.3% against 3.1% in NGT individuals, P=.0003). Also, this haplotype was associated with decreased levels of adiponectin. We also identified three mutations in exon 3: I164T, R221S, and H241P, but, owing to the low frequencies of them, associations with type 2 diabetes could not be evaluated. The subjects carrying the R221S mutation had plasma adiponectin levels lower than those without the mutation (2.10 mu g/ml [1.35-2.55 mu g/ml] vs. 6.68 mu g/ml [3.90-11.23 mu g/ml], P=.015). Similarly, the I164T mutation carriers had mean plasma adiponectin levels lower than those noncarriers (3.73 mu g/ml [3.10-4.35 mu g/ml] vs. 6.68 mu g/ml [3.90-11.23 mu g/ml]), but this difference was not significant (P=.17). Conclusions: We identified in the ADIPOQ gene a risk haplotype for type 2 diabetes in the Japanese Brazilian population. (C) 2010 Elsevier Inc. All rights reserved.
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EMOND, Alan et al. The effectiveness of community-based interventions to improve maternal and infant health in the Northeast of Brazil. Revista Panamericana de Salud Pública/ Pan American Journal of Public Health , v.12, n.2, p.101-110, 2002
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We evaluated insulin release and insulin sensitivity in women with basal and/or postprandial hyperglycemia but normal oral glucose tolerance test (OGTT) in previous pregnancy (GHG). These women were individually matched with females without previous hyperglycemia (NGT). Both groups consisted of normal glucose-tolerant women at the time of this study. They underwent OGTT (75g; n= 32 pairs) and hyperglycemic clamp experiments (10mmoll-1; n=27 pairs) with plasma glucose, insulin, and C-peptide measurements and calculation of insulinogenic index, first- and second-phase insulin release, and insulin sensitivity index (ISI). The GHG group showed higher glycosylated hemoglobin levels (6.2±0.6% versus 5.8±0.8%; P<0.05); lower insulinogenic index at 30min (134.03±62.69pmolmmol-1 versus 181.59±70.26pmolmmoll-1; P<0.05) and diminished C-peptide response in relation to glucose (4.05±0.36nmolmmol-1 versus 4.23±0.36nmolmmol-1; P<0.05) at OGTT. Both groups did not show difference in insulin secretion and ISI by hyperglycemic clamp technique. We concluded that in up to 12 years from index pregnancy, women with previous GHG, presenting normal glucose tolerance and well-matched with their controls, showed β-cell dysfunction without change in ISI. As women with previous GHG are at risk of type 2 diabetes, β-cell dysfunction may be its primary defect. © 2003 Elsevier B.V. All rights reserved.
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Doppler echocardiography has been used for the diagnosis of anthracycline-induced cardiotoxicity. However, few data are available that include asymptomatic children previously treated with a low cumulative dose of this drug and therefore have a low risk of cardiac dysfunction. The aim of this study was to evaluate after-exercise cardiac function in asymptomatic children previously treated with a low cumulative dose of anthracycline and no clinical or laboratory evidence of cardiotoxicity. Doppler echocardiography was performed before and immediately after physical exercise in 29 children aged 5 to 17 years (anthracycline [ADRIA] group). All had finished cancer treatment with anthracycline derivatives for ≥1 year (cumulative dose 100 mg/m2). Results were compared with those from age- and gender-matched healthy children (control group; n = 26) using the Mann-Whitney rank test. Exercise-induced cardiac function changes within groups were analyzed using Wilcoxon's signed-rank test. Exercise induced significant increases in left ventricular systolic function indexes in both groups. However, the ADRIA group had significantly lower changes in left ventricular ejection fraction (ADRIA group 0.71 ± 0.02 vs 0.80 ± 0.04 and control group 0.71 ± 0.02 vs 0.89 ± 0.05, p = 0.0017) and end-systolic stress-volume index (ADRIA group 4.59 ± 0.69 vs 6.4 ± 2.0 g.cm-2/ml.m-2 and control group 5.49 ± 0.98 vs 11.54 ± 2.86 g.cm-2/ml.m-2; p <0.0001), indicating decreased functional systolic reserve. In conclusion, asymptomatic children previously treated with low cumulative doses of anthracycline had decreased functional systolic reserve evidenced by exercise, suggesting a nonclinically manifested cardiotoxicity. © 2007 Elsevier Inc. All rights reserved.
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The incidence of penile cancer varies between populations but is rare in developed nations. Penile cancer is associated with a number of established risk factors and associated diseases including phimosis with chronic inflammation, human papillomavirus (HPV) infection, poor hygiene and smoking. The objective of this study was to identify genes related to this type of cancer. The detection of HPV was analyzed in 47 penile squamous cell carcinoma samples. HPV DNA was detected in 48.9% of penile squamous cell carcinoma cases. High-risk HPV were present in 42.5% of cases and low-risk HPV were detected in 10.6% of penile squamous cell carcinomas. The RaSH approach identified differential expression of Annexin A1 (ANXA1), p16, RPL6, PBEF1 and KIAA1033 in high-risk HPV positive penile carcinoma; ANXA1 and p16 were overexpressed in penile squamous cells positive for high-risk HPVs compared to normal penile samples by qPCR. ANXA1 and p16 proteins were significantly more expressed in the cells from high-risk HPV-positive penile carcinoma as compared to HPV-negative tumors (p<0.0001) independently of the subtype of the carcinoma. Overexpression of ANXA1 might be mediated by HPV E6 in penile squamous cell carcinoma of patients with high-risk HPVs, suggesting that this gene plays an important role in penile cancer. © 2013 Calmon et al.
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Abstract. Background: This study investigated the hypothesis that long-term orange juice consumption (≥ 12 months) was associated with low risk factors for cardiovascular disease in adult men and women with normal and moderately high cholesterol blood levels. Methods. The sample consisted of 103 men (18-66 y) and 26 women (18-65 y); all were employees of an orange juice factory with daily access to free orange juice. The results showed that 41% of the individuals consumed 2 cups (480 mL) of orange juice per day for at least twelve months, while 59% of the volunteers are non-consumers of orange juice. Results: Orange juice consumers with normal serum lipid levels had significantly lower total cholesterol (-11%, p <0.001), LDL-cholesterol (-18%, p < 0.001), apolipoprotein B (apo B) (-12%, p < 0.01) and LDL/HDL ratio (-12%, p < 0.04) in comparison to non-consumers, as did the consumers with moderate hypercholesterolemia: lower total cholesterol (-5%, p <0.02), LDL-cholesterol (-12%, p <0.03), apolipoprotein B (-12%, p <0.01) and LDL/HDL ratio (-16%, p <0.05) in comparison the non-consumers counterparts. Serum levels of homocysteine, HDL- cholesterol and apolipoprotein A-1, body composition and the dietary intake of food energy and macronutrients did not differ among orange juice consumers and non-consumers, but vitamin C and folate intake was higher in orange juice consumers. Conclusion: Long-term orange juice consumers had lower levels of total cholesterol, LDL-cholesterol, apo B and LDL/HDL ratio and an improvement of folate and vitamin C in their diet. © 2013 Aptekmann and Cesar; licensee BioMed Central Ltd.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Pós-graduação em Pediatria - FMB
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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The presence of human papillomavirus (HPV) was evaluated in 65 samples of prostate tumours and six samples of prostates with benign prostatic hyperplasia from individuals from Northern Brazil. We used a highly sensitive test, the Linear Array HPV Genotyping Test, to detect 37 high and low-risk HPV types. In this study, only 3% of tumour samples showed HPV infection. Our findings support the conclusion that, despite the high incidence of HPV infection in the geographic regions studied, HPV was not associated with a higher risk of prostate cancer. To our knowledge, this is the first study evaluating the frequency of HPV detection in prostatic tissue of individuals from Brazil.