Temporal profile and mechanisms of the prompt sympathoexcitation following coronary ligation in Wistar rats

Our aim was to assess the timing and mechanisms of the sympathoexcitation that occurs immediately after coronary ligation. We recorded thoracic sympathetic (tSNA) and phrenic activities, heart rate (HR) and perfusion pressure in Wistar rats subjected to either ligation of the left anterior descending coronary artery (LAD) or Sham operated in the working heart-brainstem preparation. Thirty minutes after LAD ligation, tSNA had increased (basal: 2.5±0.2 µV, 30 min: 3.5±0.3 µV), being even higher at 60 min (5.2±0.5 µV, P<0.01); while no change was observed in Sham animals. HR increased significantly 45 min after LAD (P<0.01). Sixty minutes after LAD ligation, there was: (i) an augmented peripheral chemoreflex - greater sympathoexcitatory response (50, 45 and 27% of increase to 25, 50 and 75 µL injections of NaCN 0.03%, respectively, when compared to Sham, P<0.01); (ii) an elevated pressor response (32±1 versus 23±1 mmHg in Sham, P<0.01) and a reduced baroreflex sympathetic gain (1.3±0.1 versus Sham 2.0±0.1%.mmHg-1, P<0.01) to phenylephrine injection; (iii) an elevated cardiac sympathetic tone (ΔHR after atenolol: -108±8 versus -82±7 bpm in Sham, P<0.05). In contrast, no changes were observed in cardiac vagal tone and bradycardic response to both baroreflex and chemoreflex between LAD and Sham groups. The immediate sympathoexcitatory response in LAD rats was dependent on an excitatory spinal sympathetic cardiocardiac reflex, whereas at 3 h an angiotensin II type 1 receptor mechanism was essential since Losartan curbed the response by 34% relative to LAD rats administered saline (P<0.05). A spinal reflex appears key to the immediate sympathoexcitatory response after coronary ligation. Therefore, the sympathoexcitatory response seems to be maintained by an angiotensinergic mechanism and concomitant augmentation of sympathoexcitatory reflexes

Effects of spironolactone in spontaneously hypertensive adult rats subjected to high salt intake

OBJECTIVE: To evaluate the effect of spironolactone on ventricular stiffness in spontaneously hypertensive adult rats subjected to high salt intake. INTRODUCTION: High salt intake leads to cardiac hypertrophy, collagen accumulation and diastolic dysfunction. These effects are partially mediated by cardiac activation of the renin-angiotensin-aldosterone system. METHODS: Male spontaneously hypertensive rats (SHRs, 32 weeks) received drinking water (SHR), a 1% NaCl solution (SHR-Salt), or a 1% NaCl solution with a daily subcutaneous injection of spironolactone (80 mg.kg-1) (SHRSalt- S). Age-matched normotensive Wistar rats were used as a control. Eight weeks later, the animals were anesthetized and catheterized to evaluate left ventricular and arterial blood pressure. After cardiac arrest, a doublelumen catheter was inserted into the left ventricle through the aorta to obtain in situ left ventricular pressurevolume curves. RESULTS: The blood pressures of all the SHR groups were similar to each other but were different from the normotensive controls (Wistar = 109±2; SHR = 118±2; SHR-Salt = 117±2; SHR-Salt-S = 116±2 mmHg; P<0.05). The cardiac hypertrophy observed in the SHR was enhanced by salt overload and abated by spironolactone (Wistar = 2.90±0.06; SHR = 3.44±0.07; SHR-Salt = 3.68±0.07; SHR-Salt-S = 3.46±0.05 mg/g; P<0.05). Myocardial relaxation, as evaluated by left ventricular dP/dt, was impaired by salt overload and improved by spironolactone (Wistar = -3698±92; SHR = -3729±125; SHR-Salt = -3342±80; SHR-Salt-S = -3647±104 mmHg/s; P<0.05). Ventricular stiffness was not altered by salt overload, but spironolactone treatment reduced the ventricular stiffness to levels observed in the normotensive controls (Wistar = 1.40±0.04; SHR = 1.60±0.05; SHR-Salt = 1.67±0.12; SHR-Salt- S = 1.45±0.03 mmHg/ml; P<0.05). CONCLUSION: Spironolactone reduces left ventricular hypertrophy secondary to high salt intake and ventricular stiffness in adult SHRs

Adherence to physical activity in adults with chronic diseases: ELSA-Brasil

OBJECTIVE: The objective of this study is to investigate the adherence and the factors that influence adherence to physical activity in adults with dyslipidemia, hypertension, or diabetes. METHODS: The analyses were based on data collected at the baseline of the 14,521 participants from the study ELSA-Brasil aged between 35 and 74 years. The level of leisure time physical activity was determined using the International Physical Activity Questionnaire. Logistic regression analyses were performed to examine the influence of the demographic data, socioeconomic conditions, perceived health status, and access to exercise facilities in the neighborhood on adherence to physical activity. RESULTS: Men with hypertension and dyslipidemia were more active than women. The results show that 17.8%, 15.1%, and 13.9% of the subjects who reported dyslipidemia, hypertension, and diabetes, respectively, adhere to the physical activity recommendations. The factors positively associated with adherence were higher education and income. Older individuals who reported poor perceived health, were overweight and obese, regularly smoked, and had fewer opportunities to exercise in the neighborhood presented lower adherence. CONCLUSIONS: The number of adults with dyslipidemia, hypertension, and diabetes who adhere to the physical activity recommendations is very low. Higher education and income are positively associated with adherence, while age, excess body weight, negative perceived health, regular smoking, and lack of opportunity to exercise in the neighborhood were considered barriers to physical activity

Associação entre concentração de partículas finas na atmosfera e doenças respiratórias agudas em crianças

OBJECTIVE To analyze the association between fine particulate matter concentration in the atmosphere and hospital care by acute respiratory diseases in children. METHODS Ecological study, carried out in the region of Grande Vitória, Espírito Santo, in the winter (June 21 to September 21, 2013) and summer (December 21, 2013 to March 19, 2014). We assessed data of daily count for outpatient care and hospitalization by respiratory diseases (ICD-10) in children from zero to 12 years in three hospitals in the Region of Grande Vitória. For collecting fine particulate matter, we used portable samplers of particles installed in six locations in the studied region. The Generalized Additive Model with Poisson distribution, fitted for the effects of predictor covariates, was used to evaluate the relationship between respiratory outcomes and concentration of fine particulate matter. RESULTS The increase of 4.2 µg/m3 (interquartile range) in the concentration of fine particulate matter increased in 3.8% and 5.6% the risk of medical care or hospitalization, respectively, on the same day and with six-day lag from the exposure. CONCLUSIONS We identified positive association between outpatient care and hospitalizations of children under 12 years due to acute respiratory diseases and the concentration of fine particulate matter in the atmosphere.OBJETIVO Analisar a associação entre a concentração de material particulado fino na atmosfera e atendimento hospitalar por doenças respiratórias agudas em crianças. MÉTODOS Estudo ecológico, realizado na Região da Grande Vitória, ES, no inverno (21 de junho a 21 de setembro de 2013) e no verão (21 de dezembro de 2013 a 19 de março de 2014). Foram avaliados dados de contagem diária de atendimentos ambulatoriais e hospitalizações por doenças respiratórias (CID-10) em crianças de zero a 12 anos em três hospitais da Região da Grande Vitoria. Para a coleta de material particulado fino foram utilizados amostradores portáteis de partículas instalados em seis locais na região estudada. O Modelo Aditivo Generalizado com distribuição de Poisson, ajustado para efeitos das covariáveis preditoras, foi utilizado para avaliar a relação entre os desfechos respiratórios e a concentração de material particulado fino. RESULTADOS O incremento de 4,2 µg/m3 (intervalo interquartílico) na concentração de material particulado fino aumentou em 3,8% e 5,6% o risco de atendimento ou internação, respectivamente, no mesmo dia e com seis dias de defasagem da exposição. CONCLUSÕES Foi identificada associação positiva entre atendimentos ambulatoriais e hospitalizações de crianças com até 12 anos devido a doenças respiratórias agudas e a concentração de material particulado fino na atmosfera

Non-HDL cholesterol is a good predictor of the risk of increased arterial stiffness in postmenopausal women in an urban Brazilian population

OBJECTIVES: Increased arterial stiffness is an important determinant of the risk of cardiovascular disease. Lipid profile impairment, especially hypercholesterolemia, is associated with stiffer blood vessels. Thus, the aim of this study was to determine which of the five circulating lipid components (high-density lipoprotein cholesterol (HDL-C), non-high-density lipoprotein cholesterol (non-HDL-C), low-density lipoprotein cholesterol (LDL), total cholesterol (TC) and triglycerides) is the best predictor of increased arterial stiffness in an urban Brazilian population. METHODS: A random sample of 1,662 individuals from the general population of Vitoria, Brazil (25-64 years), was selected, and lipid components were measured using standard methods. Pulse wave velocity was measured using a non-invasive automatic device, and increased arterial stiffness was defined as a pulse wave velocity ≥10 m/s. RESULTS: In men, only total cholesterol (OR=1.59; CI=1.02 to 2.48, p=0.04) was associated with the risk of increased arterial stiffness. In women, HDL-C (OR=1.99; CI=1.18 to 3.35, p=0.01) and non-HDL-C (OR=1.61; CI=1.01 to 2.56, p=0.04) were good predictors of the risk of increased arterial stiffness. However, these associations were only found in postmenopausal women (OR=2.06; CI=1.00 to 4.26, p=0.05 for HDL-C and OR=1.83; CI=1.01 to 3.33, p=0.04 for non-HDL-C). CONCLUSION: Our findings indicate that both HDL-C and non-HDL-C are good predictors of the risk of increased arterial stiffness in postmenopausal women in an urban Brazilian population and may be useful tools for assessing the risk of arterial stiffness

Pressão arterial e indicadores de função vascular de corredores com diferentes níveis de desempenho no teste cardiopulmonar

O objetivo deste estudo foi comparar os valores de pressão arterial sistólica e diastólica periférica (PASp e PADp) e central (PASc e PADc) e o índice de função vascular em corredores de rua de diferentes desempenhos. A amostra foi composta por 48 participantes, 20-40 anos, 32 corredores de rua com diferentes níveis de desempenho, e 16 indivíduos sedentários. Avaliou-se a aptidão cardiorrespiratória e a velocidade máxima de corrida, através do teste cardiopulmonar de exercício (TCPE). A pressão central e periférica foi investigada por tonometria de aplanação e a velocidade da onda de pulso (VOP) pelo equipamento Complior. O ecocardiograma foi usado para avaliar a estrutura cardíaca. ANOVA de uma via foi utilizada considerando p &lt;0,05. A ANCOVA foi usada para ajustar fatores de confusão. Corredores com desempenho superior apresentaram menor PASp que os demais grupos (120±7 vs 127±8 vs 130 ±8 mmHg). A duração da diástole foi maior nos corredores com desempenho superior (845±92 ms) em relação aos corredores com desempenho inferior (786±174 ms e controle (641±128 ms). O índice de amplificação (AI) não foi diferente entre os grupos (109 ± 21%; 109 ± 11%; 110 ± 1%) assim como a VOP (7,1 ± 1ms. 7,6 ± 1.1ms. 8,0 ± 1,1ms). Corredores com desempenho superior apresentaram maior massa do ventrículo esquerdo (MVE g/m²) em relação aos demais (116±12 g/m² vs 100±18 g/m² vs 86±13 g/m²), e menor débito cardíaco em comparação ao grupo controle (4,8±1 l/ min. vs 6,0±1 l/min). Portanto corredores com desempenho superior apresentaram maior MVE g/m², menor débito cardíaco, menor PASc e PASp, e melhor duração da diástole que seus pares sedentários, mas não apresentam melhores indicadores de função vascular na mesma comparação

Hypertension and salt intake in an urban population

OBJECTIVE: To evaluate the salt intake and urinary Na+/K+ ratio in a randomized sample from an ethnically mixed urban population. METHODS: A randomized residential sample of 2,268 individuals aged 25-64 in Vitória, ES, was selected, of whom 1,663 (73.3%) reported to the hospital for standardized tests. Salt, Na+ and K+ intake was estimated from 12-hour urine excretion (7 p.m. to 7 a.m.) and from the monthly salt consumption at home reported in the interview. Clinic arterial pressure was measured twice under standard conditions by two trained investigators, using mercury sphygmomanometry. The Student t and Tukey tests were utilized for statistical analysis. RESULTS: Urinary Na+ excretion was higher in men and individuals of lower socioeconomic level (POBJETIVO: Avaliar o consumo de sal e a relação sódio/potássio urinário em amostra randomizada de população urbana etnicamente miscigenada. MÉTODOS: Foi selecionada uma amostra randômica de 2.268 residentes de Vitória, ES, entre 25 e 64 anos de idade. Os indivíduos foram escolhidos por amostragem domiciliar realizada em 1999/2000, dos quais 1.663 (73,3%) compareceram ao hospital para a realização de exames padronizados. O consumo estimado de sal, Na+ e K+ foi determinado por meio da coleta de urina de 12h no período noturno (19h às 7h) e do gasto mensal de sal domiciliar referido durante a entrevista. A pressão arterial clínica foi medida duas vezes por diferentes pesquisadores treinados em condições padronizadas, usando esfignomamômetro de mercúrio. Para análise estatística foram utilizados o teste de Student e o teste de Tukey. RESULTADOS: A excreção urinária de Na+ foi mais alta em homens e em indivíduos de menores condições socioeconômicas (

Design of a clock and data recovery circuit in 65 nm technology

As semiconductor fabrication technology develops, the demand for higher transmission data rates constantly increases; thus there is an urgent need for a power-efficient, robust and broad bandwidth chip-to-chip communication method. A lot of work has been done to address this issue as researchers strive for more integrated inter-IC communication technology with CMOS. A high-speed serial link (HSSL) can help meet this goal. The clock and data recovery circuit (CDR) is a critical component of the HSSL. CDR is built on the receiver end of the link after proper equalization. Its purpose is to extract clock signal which is not transmitted from the driver end and to use the extracted clock signal to sample the incoming data stream with optimal timing. In this thesis, the working mechanism of the CDR is described. A CDR consists of a phase detector, a charge pump, a loop filter and a voltage-controlled oscillator. This thesis includes an overview of all the building blocks of a PLL-based CDR, derivation of the mathematical formulations of the negative feedback loop, and a report on closed loop behavioral modeling of the entire CDR and implemented CDR building blocks at transistor level with TSMC 65 nm technology PDK with a 6.4 Gbps data rate. Also, this thesis provides a detailed noise analysis of the CDR. Lastly, some future work and possible design improvements are proposed

Lack of association between subclinical hypothyroidism and carotid–femoral pulse wave velocity in a cross-sectional analysis of the ELSA–Brasil

BACKGROUND There is little available data on carotid–femoral pulse wave velocity (cf-PWV) in subjects with subclinical hypothyroidism (SCH). We aimed to analyze the association between SCH and cf-PWV using baseline data from the Brazilian Longitudinal Study of Adult Health (ELSA–Brasil). METHODS We included subjects with normal thyroid function (thyrotropin (TSH): 0.4–4.0 mIU/l, and normal free thyroxine (FT4: 0.8–1.9 ng/dl) and SCH (TSH > 4.0 mIU/l and normal FT4) evaluated for cf-PWV in a crosssectional analysis. We excluded individuals using medications that interfere in thyroid function, antihypertensives, or diuretics, and subjects with chronic kidney disease or previous cardiovascular disease. Generalized linear and logistic regression models evaluated cf-PWV as a dependent variable and SCH as an independent variable, adjusted for cardiovascular risk factors.RESULTS Of 8,341 subjects (52.3% women), 7,878 (94.4%) were euthyroid and 463 (5.6%) showed SCH. The median age was 50 years (interquartile range: 44–56). The groups differed by age, sex, body mass index, glomerular filtration rate, and C-reactive protein. SCH was not associated with cf-PWV in the full-adjusted linear model (β = −0.039; P = 0.562) and with cf-PWV >75th percentile in the full-adjusted logistic model (odds ratio = 0.94; 95% confidence interval = 0.72–1.22). CONCLUSION In a large sample, SCH was not associated with increased cf-PWV

Sensibilidade e especificidade no diagnóstico de hipertensão por diferentes métodos

OBJECTIVE: To evaluate sensitivity and specificity of different protocols for blood pressure measurement for the diagnosis of hypertension in adults. METHODS: Cross-sectional study conducted in a non-probabilistic sample of 250 public servants of both sexes aged 35 to 74 years in Vitória, southeastern Brazil, between 2008 and 2010. The participants had their blood pressure measured using three different methods: clinic measurement, self-measured and 24-hour ambulatory measurement. They were all interviewed to obtain sociodemographic information and had their anthropometric data (weight, height, waist circumference) collected. Clinic measurement and self-measured were analyzed against the gold standard ambulatory measurement. Measures of diagnostic performance (sensitivity, specificity, accuracy and positive and negative predictive values) were calculated. The Bland & Altman method was used to evaluate agreement between ambulatory measurement (standard deviation for daytime measurements) and self-measured (standard deviation of four measurements). A 5% significance level was used for all analyses. RESULTS: Self-measured blood pressure showed higher sensitivity (S=84%, 95%CI 75;93) and overall accuracy (0.817, pOBJETIVO: Evaluar la sensibilidad y la especificidad de diferentes protocolos de medida de la presión arterial para el diagnóstico de la hipertensión en adultos. MÉTODOS: Estudio transversal con muestra no probabilística de 250 funcionarios de ambos sexos de institución pública en el grupo etáreo de 35 a 74 años en Vitoria, Sureste de Brasil, entre 2008 y 2010. Los participantes tuvieron sus presiones arteriales medidas por tres métodos: medida clínica, automedida y medida por ambulatorio por 24 horas. Se colectaron datos antropométricos (peso, estatura y circunferencias) y se realizó entrevista. Los métodos fueron confrontados y analizados con relación a la medida por ambulatorio 24h (patrón-oro). Se calcularon las medidas de desempeño diagnóstico: sensibilidad, especificidad, valores predictivos positivos y negativos y precisión. La metodología de Bland & Altman fue utilizada para verificar la concordancia entre la variable presórica en la automedida (desviación estándar de las cuatro medidas). Se adoptó nivel de 5% de significancia para todas las pruebas. RESULTADOS: La automedida presentó mayor sensibilidad (S=84%; IC95%: 75;93) y precisión global (0,817; pOBJETIVO: Avaliar a sensibilidade e a especificidade de diferentes protocolos de medida da pressão arterial para o diagnóstico da hipertensão em adultos. MÉTODOS: Estudo transversal com amostra não probabilística de 250 funcionários de ambos os sexos de instituição pública na faixa etária de 35 a 74 anos em Vitória, ES, entre 2008 e 2010. Os participantes tiveram suas pressões arteriais aferidas por três métodos: medida clínica, automedida e medida ambulatorial por 24 horas. Foram coletados dados antropométricos (peso, estatura e circunferências) e realizada entrevista. Os métodos foram confrontados e analisados em relação à medida ambulatorial 24 h (padrão-ouro). Foram calculadas as medidas de desempenho diagnóstico: sensibilidade, especificidade, valores preditivos positivos e negativos e acurácia. A metodologia de Bland & Altman foi utilizada para verificar a concordância entre a variabilidade pressórica na medida ambulatorial (desvio-padrão relativo ao período diurno) e a variabilidade pressórica na automedida (desvio-padrão das quatro medidas). Adotou-se nível de significância de 5% para todos os testes. RESULTADOS: A automedida apresentou maior sensibilidade (S = 84%; IC95%: 75;93) e acurácia global (0,817; p < 0,001) no diagnóstico da hipertensão que a medida clínica (S = 79%; IC95%: 73;86 e AG = 0,815; p < 0,001). Apesar da forte correlação com o método de medida ambulatorial durante a vigília (r = 0,843; p = 0,000), a automedida não mostrou boa concordância com o referido método para a medida sistólica (viés = 5,82; IC95%: 4,49;7,15). Foram identificados sete (2,8%) indivíduos com hipertensão do avental branco, 26 (10,4%) com hipertensão mascarada e 46 (18,4%) com efeito do avental branco. CONCLUSÕES: Os resultados sugerem que a automedida apresenta sensibilidade superior à medida clínica para identificar verdadeiros hipertensos na população. Os valores de predição negativa encontrados confirmam a superioridade da automedida em relação à medida clínica no que tange à capacidade do teste em apontar os indivíduos verdadeiramente normotensos. Contudo, não pode substituir a medida clínica, que ainda é o método mais fidedigno