Comparison of cardiorespiratory responses between constant and incremental load exercises below, above and at the ventilatory anaerobic threshold

OBJECTIVE: To apply different analytical methodologies to data from continuous ramp tests (CRT) and discontinuous step tests (DST), and compare responses from cardiorespiratory parameters. METHOD: Eight men performed spirometric tests on an electrically braked cycle ergometer: CRT increasing from 20 to 25 W.min-1 and DST in 15-min steps, each based on the ventilatory anaerobic threshold (VAT) for CRT. Step 1 was 70% VAT; step 2, 100% VAT; and step 3, 130% VAT. VAT was determined as loss of parallelism between O2 uptake (VO2) and CO2 output (VCO2). Heart rate (HR, bpm), VCO2, VO2 (ml.min-1), VO2 (ml.kg.min-1) and ventilation (VE L.min-1) values for CRT were obtained as moving averages of eight breath-to-breath respiratory cycles, using linear regression. For DST, means were applied from the third to fifteenth minute of the steps. Statistical comparisons utilized the Kolmogorov-Smirnov test, ANOVA, post-hoc Tukey-Kramer test and linear regression, with significance limit of p0.05), but VO2 was different between VAT and all steps (p0,05), porém VO2 relativo foi diferente (p<0,05) entre LAV e todos os degraus; a FC mostrou diferença (p<0,05) entre LAV e degrau 3, e na análise entre os três degraus houve diferença (p<0,05). CONCLUSÃO: Os resultados indicam que a regressão linear foi eficaz para estimar as variáveis cardiorrespiratórias. Em relação aos protocolos, verificou-se que para a obtenção no TDD de valores cardiorrespiratórios similares ao LAV do TCR foi necessário diminuir a potência em 30%.16316

A amplitude de distribuição dos glóbulos vermelhos (rdw) pode ser considerado como um marcador da atividade da doença de Crohn?

Introduction: Recently, it has been suggested an association between red cell distribution width (RDW) and Crohn’s disease activity index (CDAI), but its use is not yet performed in daily clinical practice. Objectives: To determine whether RDW can be used as a marker of Crohn’s disease (CD) activity. Methods: This was a cross-sectional study including patients with CD, observed consecutively in an outpatient setting between January 1st and September 30th 2013. Blood cell indices, erythrocyte sedimentation rate (ESR), and C-reactive protein were measured. CD activity was determined by CDAI (active disease if CDAI ≥ 150). Associations were analyzed using logistic regression (SPSS version 20). Results: 119 patients (56% female) were included in the study with a mean age of 47 years (SD 15.2). Twenty patients (17%) had active disease. The median RDW was 14.0 (13---15). There was an association between RDW and disease activity (p = 0.044). After adjustment for age and gender, this association remained consistent (OR 1.20, 95% CI 1.03---1.39, p = 0.016). It was also found that the association between RDW and disease activity was independent of hemoglobin and ESR (OR 1.36, 95% CI 1.08---1.72, p = 0.01) and of biologic therapy (OR 1.19, 95% CI 1.03---1.37, p = 0.017). A RDW cutoff of 16% had a specificity and negative predictive value for CDAI ≥ 150 of 88% and 86%, respectively. Conclusion: In this study, RDW proved to be an independent and relatively specific marker of CD activity. These results may contribute to the implementation of this simple parameter, in clinical practice, aiming to help therapeutic decisions.Introduc¸ão: Recentemente, tem vindo a ser sugerida uma associac¸ão entre o valor de RDW e a atividade da doença de Crohn (DC), mas a sua utilização não está ainda implementada na prática clínica diária. Objetivos: Determinar se o RDW pode ser utilizado como marcador de atividade da DC. Métodos: Estudo transversal, em doentes com DC, observados consecutivamente em consulta de Doença Inflamatória Intestinal, entre 1 de janeiro e 30 de setembro de 2013. Analisaram-se índices do hemograma, proteína C reativa e velocidade de sedimentação. A gravidade da doença foi avaliada pelo Crohn’s disease activity index (doença ativa se CDAI≥150). As associações foram estudadas usando a regressão logística (SPSS Statistics V20). Resultados: Incluídos 119 doentes (56% do sexo feminino), com idade média de 47 anos (DP 15,2 anos). Vinte doentes (17%) tinham doença ativa. O valor do RDW mediano foi 14,0% (13-15). Verificou-se uma associação entre RDW e atividade da doença (p = 0,044). Após ajuste para a idade e o sexo, esta associação manteve-se consistente (OR 1,20; 95% CI 1,03-1,39; p = 0,016). Verificou-se ainda que a associação do valor do RDW com a atividade da doença foi independente do valor da hemoglobina e da velocidade de sedimentação (OR 1,36; 95% CI 1,08-1,72; p = 0,01) e da terapêutica biológica (OR 1,19; 95% CI 1,03-1,37; p = 0,017). Para um valor de corte de RDW de 16%, a especificidade e o valor preditivo negativo de CDAI≥ 150 foram de 88% e 86%, respetivamente. Conclusão: Neste estudo, o valor do RDW demonstrou ser um marcador independente e relativamente específico da atividade da doenc¸a de Crohn. Estes resultados poderão contribuir para a aplicação deste parâmetro simples, na prática clinica diária, visando auxiliar decisões terapêuticas

Pseudomyxoma peritonei: a clinical case of this poorly understood condition

BACKGROUND: Pseudomyxoma peritonei is an uncommon condition with an estimated incidence of one to two per million (worldwide) per year. It is characterized by the peritoneal deposition of mucinous tumors, most commonly of the appendix, and occasionally from the ovary, coupled by mucinous ascites. CASE PRESENTATION: We report the case of a 76-year-old woman who presented with increased abdominal girth and dyspnea for 2 weeks. She was diagnosed as a case of pseudomyxoma peritonei. She was submitted to right oophorectomy, omentectomy, and pseudomyxoma debulking. The histology was compatible with a mucinous tumor of colorectal/appendicular origin. Chemotherapy was not administered because of her functional status. Two years and 8 months later, she refers with postprandial fullness and has moderate ascites

Is there a proximal shift in the distribution of colorectal adenomas?

INTRODUCTION: Several studies have shown a proximal shift of colorectal cancer (CRC) during the last decades. However, few have analyzed the changing distribution of adenomas over time. AIM: The aim of this study was to compare the site and the characteristics of colorectal adenomas, in a single center, during two periods. METHODS: We conducted a retrospective, observational study in a single hospital of adenomas removed during a total colonoscopy in two one-year periods: 2003 (period 1) and 2012 (period 2). Patients with inflammatory bowel disease, familial adenomatous polyposis, hereditary non-polyposis colorectal cancer syndrome, or history of CRC were excluded from the study. The χ(2) statistical test was performed. P values less than 0.05 were considered statistically significant. RESULTS: During the two considered periods, a total of 864 adenomas from 2394 complete colonoscopies were analyzed: 333 adenomas from 998 colonoscopies during period 1 and 531 adenomas from 1396 colonoscopies during period 2. There was a significant increase in the proportion of adenomatous polyps in the proximal colon from period 1 to 2 (30.6% to 38.8% (p = 0.015)). Comparing the advanced features of adenomas between the two periods, it was noted that in period 2, the number of adenomas with size ≥1 cm (p = 0.001), high-grade dysplasia (p = 0.001), and villous features (p < 0.0001) had a significant increase compared to period 1. CONCLUSION: Incidence of adenomatous polyps in the proximal colon as well as adenomas with advanced features has increased in the last years. This finding may have important implications regarding methods of CRC screening

Analysis of spectral indexes for heart rate variability in middle-aged men and postmenopausal women

OBJECTIVE: To analyze and compare heart rate variability (HRV) in middle-aged men and women under resting conditions. METHOD: Ten men (54 &plusmn; 3.2 years) and fourteen postmenopausal women (56 &plusmn; 2.6 years) who were not using hormonal therapy were studied. Heart rates (HR) and R-R intervals (iR-R) on a beat-to-beat basis were obtained from electrocardiograms over an eight-minute period under resting conditions, in the supine and sitting positions. The HRV was analyzed in the frequency domain by means of fast Fourier transforms and the low (LF) and high (HF) frequency bands were obtained and presented as normalized units (LFnu and HFnu) and the LF/HF ratio. Wilcoxon and Mann-Whitney non-parametric statistical tests were used, with the significance level set at 5%. RESULTS: Comparing between the groups, the women presented significantly higher HFnu and lower LFnu and LF/HF ratios than did the men (p0.05) were found in the HRV indexes between the supine and sitting positions for either study group. CONCLUSION: Our results show greater vagal modulation and lower sympathetic activity in autonomic heart rate control among women than among men of similar age. This suggests that the gender-related autonomic differences are not solely dependent on estrogen levels, since the women studied were already postmenopausal. Other factors may be contributing towards these differences.OBJETIVO: Analisar e comparar a variabilidade da freqüência cardíaca (VFC), em repouso, de homens e mulheres de meia-idade. MÉTODOS: Foram estudados 10 homens (54 &plusmn; 3,2 anos) e 14 mulheres na pós-menopausa (56 &plusmn; 2,6 anos) que não faziam uso de terapia hormonal. A freqüência cardíaca (FC) e os intervalos R-R foram obtidos a partir do eletrocardiograma, batimento a batimento, durante 8 minutos em repouso, nas posições supina e sentada. A VFC foi analisada no domínio da freqüência, usando a transformada rápida de Fourier, por meio da qual foram obtidas as bandas de baixa (BF) e alta freqüência (AF), as quais foram expressas em unidades normalizadas (AFun) e (BFun) e na razão BF/AF. Foram utilizados os testes estatísticos não-paramétricos de Mann-Whitney e de Wilcoxon, com nível de significância de alfa= 5%. RESULTADOS: Na comparação intergrupo, as mulheres apresentaram maiores valores da banda AFun e menores valores da banda BFun e da razão BF/AF em relação aos homens, diferenças essas significativas (p<0,05). Na comparação intragrupo, não foram observadas diferenças significativas nos índices de VFC entre as posições supina e sentada para os 2 grupos estudados. CONCLUSÃO: Nossos resultados mostram uma maior modulação vagal e menor simpática no controle autonômico da FC para as mulheres em comparação aos homens de mesma idade, o que sugere que as diferenças autonômicas relacionadas ao gênero não se devem unicamente aos níveis hormonais de estrogênio, uma vez que as mulheres estudadas já se encontravam na fase pós-menopausa. Outros fatores podem estar contribuindo para essas diferenças.401406Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Evolution of Chagas’ disease in Brazil. Epidemiological perspective and challenges for the future: a critical review

Aims: This paper aimed to provide a critical review of the evolution of Chagas’ disease in Brazil, its magnitude, historical development and management, and challenges for the future. Methods: A literature search was performed using PubMed, SciELO and Google Scholar and throughout collected articles’ references. Narrative analysis was structured around five main themes identified: vector transmission, control program, and transfusion, oral and congenital transmission. Results: In Brazil, the Chagas’ disease Control Program was fully implemented in the 1980s, when it reached practically all the endemic areas, and in 1991, the Southern Cone Initiative was created, aiming to eliminate the disease transmission through eliminating the Triatoma infestans and controlling blood banks. As a result, the prevalence of chagasic donors in blood banks reduced from 4.4% in the 80s to 0.2% in 2005. In 2006, PAHO certified the interruption of transmission of Chagas’ disease through this vector in Brazil. However, there are still challenges, such as the domiciliation of new vector species, the need for medical care of the infected individuals, the prevention of alternative mechanisms of transmission, the loss of political concern regarding the disease and, the weakening of the control program. Conclusion: Despite the progress towards control, there are still many challenges ahead to maintain and expand such control and minimise the risk of re-emergence

Lepton Acceleration in Pulsar Wind Nebulae

Pulsar Wind Nebulae (PWNe) act as calorimeters for the relativistic pair winds emanating from within the pulsar light cylinder. Their radiative dissipation in various wavebands is significantly different from that of their pulsar central engines: the broadband spectra of PWNe possess characteristics distinct from those of pulsars, thereby demanding a site of lepton acceleration remote from the pulsar magnetosphere. A principal candidate for this locale is the pulsar wind termination shock, a putatively highly-oblique, ultra-relativistic MHD discontinuity. This paper summarizes key characteristics of relativistic shock acceleration germane to PWNe, using predominantly Monte Carlo simulation techniques that compare well with semi-analytic solutions of the diffusion-convection equation. The array of potential spectral indices for the pair distribution function is explored, defining how these depend critically on the parameters of the turbulent plasma in the shock environs. Injection efficiencies into the acceleration process are also addressed. Informative constraints on the frequency of particle scattering and the level of field turbulence are identified using the multiwavelength observations of selected PWNe. These suggest that the termination shock can be comfortably invoked as a principal injector of energetic leptons into PWNe without resorting to unrealistic properties for the shock layer turbulence or MHD structure.Comment: 19 pages, 5 figures, invited review to appear in Proc. of the inaugural ICREA Workshop on "The High-Energy Emission from Pulsars and their Systems" (2010), eds. N. Rea and D. Torres, (Springer Astrophysics and Space Science series

Nutritional status and growth of indigenous Xavante children, Central Brazil

<p>Abstract</p> <p>Background</p> <p>The aim of this study was to characterize the nutritional status of Xavante Indian children less than 10 years of age in Central Brazil and to evaluate the hypothesis of an association between child nutrition and socioeconomic differentiation in this population.</p> <p>Methods</p> <p>A cross-sectional study was conducted in July 2006 that included all children under the age of 10 from the Xavante village Pimentel Barbosa in Mato Grosso, Brazil. The data collected included weight, height, and sociodemographic information. Sociodemographic data were used to generate two indices ("income" and "wealth") and to determine the proportion of adults in each household. Descriptive analyses were performed for weight-for-age (W/A), height-for-age (H/A), and weight-for-height (W/H) using the NCHS and the WHO growth references. Univariate and multivariate analyses were conducted using H/A and W/A as a response variables.</p> <p>Results</p> <p>Of a total of 246 children under the age of ten residing in the village, 232 (94.3%) were evaluated. Following the NCHS reference, 5.6% of children under the age of ten presented low W/A and 14.7% presented low H/A. Among children under the age of five, deficit percentages for weight and height were 4.5% and 29.9%, respectively, following the WHO curves. Among children < 2 years of age, H/A index variability was found to be directly related to child's age and inversely related to the proportion of adults in the household. Maternal BMI was positively associated with growth for children from 2 to 4 years of age, explaining 11.5% of the z-score variability for the H/A index. For children 5 years of age and older, the wealth index and maternal height were positively associated with H/A. No significant associations were found using W/A as the dependent variable.</p> <p>Conclusion</p> <p>This study demonstrated that undernutrition, in particular linear growth deficit, is a notable health issue for Xavante children. These findings contrast with the nutritional profile observed among Brazilian children nationally, which is characterized by a sharp decline in child undernutrition in recent decades, even in the poorest regions of the country. This discrepancy calls attention to the persistent health disparities that exist between indigenous and non-indigenous people in Brazil.</p