Quantitative analysis of cardiac lesions in chronic canine chagasic cardiomyopathy

Lesions observed in chronic chagasic cardiopathy frequently produce electrocardiographic alterations and affect cardiac function. Through a computerized morphometrical analysis we quantified the areas occupied by cardiac muscle, connective and adipose tissues in the right atrium of dogs experimentally infected with Trypanosoma cruzi. All of the infected dogs showed chronic myocarditis with variable reduction levels of cardiac muscle, fibrosis and adipose tissue replacement. In the atrial myocardium of dogs infected with Be78 and Be62 cardiac muscle represented 34 and 50%, fibrosis 28 and 32% and adipose tissue 38 and 18%, respectively. The fibrosis observed was both diffuse and focal and mostly intrafascicular, either partially or completely interrupting the path of muscle bundles. Such histological alterations probably contributed to the appearance of electrocardiographic disturbances verified in 10 out 11 dogs which are also common in human chronic chagasic cardiopathy. Fibrosis was the most important microscopic occurrence found since it produces rearrangements of collagen fibers in relation to myocardiocytes which causes changes in anatomical physiognomy and mechanical behavior of the myocardium. These abnormalities can contribute to the appearance of cardiac malfunction, arrythmias and congestive cardiac insufficiency as observed in two of the analyzed dogs. Strain Be78 caused destruction of atrial cardiac muscle higher than that induced by strain Be62.

Characterization of Nitric Oxide Reductase (NOR) from pseudomonas nautica, a study on biologic nitric oxide reduction

Dissertation submitted to obtain the phD degree in Biochemistry, specialty in Physical- Biochemistry, by the Faculdade de Ciências e Tecnologia from the Universidade Nova de Lisboa

Microglial clearance function: dependence on phenotypes

Dissertação para obtenção do Grau de Mestre em Genética Molecular e Biomedicina

O controlo da tuberculose em Portugal : uma apreciação crítica epidemiológica gl

RESUMO - Com tanto ruído informativo e peças de informação incompletas e descontextualizadas, relativos ao controlo da tuberculose em Portugal, a chegarem ao cidadão e aos profissionais de saúde, não é fácil que eles disponham do conhecimento necessário ao desempenho dos respectivos papéis nesse controlo. O presente artigo pretende contribuir para um ganho real em conhecimento quanto (1) ao progresso no controlo da tuberculose em Portugal, enquadrado na evolução desse controlo noutras regiões pertinentes, e (2) aos aspectos do conhecimento disponível e da intervenção na população portuguesa que suscitem especial atenção, para melhoria no futuro imediato. Tem como estratégia integrar, e elevar ao nível de conhecimento, a informação disponibilizada nas fontes mais credíveis e pertinentes, valorizada no contexto da validade das mesmas fontes e da coerência dos diversos componentes. Relata o resultado de um exercício independente de apreciação crítica, com uma perspectiva epidemiológica. São observados: a situação actual, sobretudo a relativa aos anos de 2006 e 2007, e o desempenho do Programa Nacional de Controlo da Tuberculose (PNT), ambos relativizados à evolução recente e ao panorama internacional. O exercício de observação e revisão independentes baseia-se numa selecção de informação oficial e segue o mesmo método de abordagem que a O.M.S. faz nos seus relatórios anuais, à semelhança de outros exercícios já antes realizados. O controlo da tuberculose tem prosseguido a sua tímida, mas firme, evolução favorável, aproximando-se do nível já conseguido nos países seus vizinhos da Europa Ocidental. Em 2007, Portugal contribuiu para os 9 milhões de casos novos anuais, estimados no mundo, com 2916 casos notificados. A este número corresponde a taxa de incidência notificada de 25,7 por 100 000 habitantes e uma redução de 14% em relação ao ano anterior. Esta evolução afigura-se animadora, ainda que seja desejável um impacte mais acentuado do PNT, conforme é de esperar considerando o grau de desenvolvimento do País. A taxa de detecção de casos novos estimada é elevada e continua uma das melhores da Europa Ocidental — o que desfavorece artificialmente a imagem notificada do País, relativamente aos países com pior capacidade de detecção. A taxa de sucesso terapêutico melhorou de novo, situando- -se acima da meta de 85% preconizada pela O.M.S, para um bom controlo da tuberculose. Uma das consequências importantes é que se consegue um melhor aproveitamento da detecção habitualmente alcançada. O conhecimento no seu conjunto aponta para que o grau de controlo possa e deva realmente ser melhorado, sendo imperiosa a discriminação positiva das áreas geográficas e dos grupos populacionais em que tende a concentrar-se a emergência de maior número de casos e de resistências aos medicamentos. Deverão assim ser reforçados selectivamente tanto os meios de detecção e de intervenção clínica, como a qualidade da organização local da intervenção, para o cumprimento efectivo da estratégia DOTS. Enquanto programa vertical que atravessa os diversos níveis do sistema de cuidados de saúde, o desempenho do PNT sofre os efeitos das atribulações desses serviços, sobretudo os de cuidados primários, funcionando como uma «situação-marcadora» quanto ao desempenho do sistema de saúde. A evidência é de que é nesta primeira linha de cuidados que se decide o sucesso na detecção e no tratamento dos casos de tuberculose, reflectindo-se também aí o grau de desenvolvimento social e os comportamentos das populações, por sua vez determinantes do risco de doença e do sucesso terapêutico. ------------------- ABSTRACT - It is not easy that both the citizen and health professionals get enabled with the required knowledge, in order do play the corresponding roles in the control of tuberculosis, considering all the information noise and incomplete, out of context information pieces about the subject, that reach them. This paper is envisaging to contribute for a real gain in knowledge, regarding: (1) the progress in tuberculosis control in Portugal, framed by the evolution of such control in other pertinent regions and (2) the available knowledge and intervention aspects in the Portuguese population that require a special attention, for improvement. The article’s strategy is to integrate, and raise to a knowledge level, information provided by the most accredited and pertinent sources, interpreted as a function of the validity context of the same sources and of the coherence of the several components. Two aspects are observed: the current situation, in particular concerning years 2006 and 2007, and the performance of the National Programme for the Tuberculosis Control (PNT), both made relative to the recent evolution and to the international panorama. This independent observation and revision exercise is based on a selection of official information and follows the same approach that the World Health Organization (W.H.O.) uses in its annual reports, like other similar exercises previously undertaken. The control of tuberculosis is evolving in a shy, but firm, fashion, getting closer to the level already attained by the neighbor countries, in Western Europe. Portugal has contributed with 2916 new notified cases, to the 9 million annual cases estimated in the world, in 2007. This number corresponds to an incidence rate, for notified cases, of 25.7 per 100000 population, and to a reduction of 14% in one year. Such evolution seems encouraging, although a greater impact of PNT is desirable, as expected in relation to the degree of the Country development. Estimated new cases detection rate is high and keeps being one of the best in Western Europe — and this artificially disadvantages the notified image of the Country, as compared with other countries having a worst detection capacity. Treatment success rate has improved again and it is above the 85% target proposed by W.H.O., so that a good control of the disease is achieved. One of the important consequences is a better use of the attained detection. Altogether, knowledge suggests that the degree of control can and must be in fact better; and that a positive discrimination of geographic areas and population groups, in which a greater number of new cases and drug resistances tend to concentrate, is mandatory. Therefore, either clinical detection and intervention resources, or the quality of the local intervention organization have to be reinforced, if a total fulfillment of DOTS strategy is to be obtained. As a vertical programme that crosses the several levels of the health care system, PNT performance suffers the effects of services tribulations, mainly primary care, thus acting as a «markersituation » as to this system performance. Evidence shows that it is in this first line of care that success in both detection and treatment of tuberculosis cases is decided; and that this level also reveals the degree of social developmen

RuSe Electrocatalysts and Single Wall Carbon Nanohorns Supports for the Oxygen Reduction Reaction

Selenium modified ruthenium electrocatalysts supported on carbon black were synthesized using NaBH4 reduction of the metal precursor. Prepared Ru/C electrocatalysts showed high dispersion and very small averaged particle size. These Ru/C electrocatalysts were subsequently modified with Se following two procedures: (a) preformed Ru/carbon catalyst was mixed with SeO2 in xylene and reduced in H2 and (b) Ru metal precursor was mixed with SeO2 followed by reduction with NaBH4. The XRD patterns indicate that a pyrite-type structure was obtained at higher annealing temperatures, regardless of the Ru:Se molar ratio used in the preparation step. A pyrite-type structure also emerged in samples that were not calcined; however, in this case, the pyrite-type structure was only prominent for samples with higher Ru:Se ratios. The characterization of the RuSe/C electrocatalysts suggested that the Se in noncalcined samples was present mainly as an amorphous skin. Preliminary study of activity toward oxygen reduction reaction (ORR) using electrocatalysts with a Ru:Se ratio of 1:0.7 indicated that annealing after modification with Se had a detrimental effect on their activity. This result could be related to the increased particle size of crystalline RuSe2 in heat-treated samples. Higher activity of not annealed RuSe/C catalysts could also be a result of the structure containing amorphous Se skin on the Ru crystal. The electrode obtained using not calcined RuSe showed a very promising performance with a slightly lower activity and higher overpotential in comparison with a commercial Pt/C electrode. Single wall carbon nanohorns (SWNH) were considered for application as ORR electrocatalysts' supports. The characterization of SWNH was carried out regarding their tolerance toward strong catalyzed corrosion conditions. Tests indicated that SWNH have a three times higher electrochemical surface area (ESA) loss than carbon black or Pt commercial electrodes.

On the numerical computation of the Mittag-Leffler function

Recently simple limiting functions establishing upper and lower bounds on the Mittag-Leffler function were found. This paper follows those expressions to design an efficient algorithm for the approximate calculation of expressions usual in fractional-order control systems. The numerical experiments demonstrate the superior efficiency of the proposed method.

Molecular modulation of brain development and function: lessons from “old” and “new”

Dissertation presented to obtain the Ph.D degree in Biology

Utilidade do Doppler Tecidular na Predição de Eventos Arrítmicos em Adultos com Tetralogia de Fallot Corrigida

INTRODUCTION: Adults with repaired tetralogy of Fallot (TOF) may be at risk for progressive right ventricular (RV) dilatation and dysfunction, which is commonly associated with arrhythmic events. In frequently volume-overloaded patients with congenital heart disease, tissue Doppler imaging (TDI) is particularly useful for assessing RV function. However, it is not known whether RV TDI can predict outcome in this population. OBJECTIVE: To evaluate whether RV TDI parameters are associated with supraventricular arrhythmic events in adults with repaired TOF. METHODS: We studied 40 consecutive patients with repaired TOF (mean age 35 +/- 11 years, 62% male) referred for routine echocardiographic exam between 2007 and 2008. The following echocardiographic measurements were obtained: left ventricular (LV) ejection fraction, LV end-systolic volume, LV end-diastolic volume, RV fractional area change, RV end-systolic area, RV end-diastolic area, left and right atrial volumes, mitral E and A velocities, RV myocardial performance index (Tei index), tricuspid annular plane systolic excursion (TAPSE), myocardial isovolumic acceleration (IVA), pulmonary regurgitation color flow area, TDI basal lateral, septal and RV lateral peak diastolic and systolic annular velocities (E' 1, A' 1, S' 1, E' s, A' s, S' s, E' rv, A' rv, S' rv), strain, strain rate and tissue tracking of the same segments. QRS duration on resting ECG, total duration of Bruce treadmill exercise stress test and presence of exercise-induced arrhythmias were also analyzed. The patients were subsequently divided into two groups: Group 1--12 patients with previous documented supraventricular arrhythmias (atrial tachycardia, fibrillation or flutter) and Group 2 (control group)--28 patients with no previous arrhythmic events. Univariate and multivariate analysis was used to assess the statistical association between the studied parameters and arrhythmic events. RESULTS: Patients with previous events were older (41 +/- 14 vs. 31 +/- 6 years, p = 0.005), had wider QRS (173 +/- 20 vs. 140 +/- 32 ms, p = 0.01) and lower maximum heart rate on treadmill stress testing (69 +/- 35 vs. 92 +/- 9%, p = 0.03). All patients were in NYHA class I or II. Clinical characteristics including age at corrective surgery, previous palliative surgery and residual defects did not differ significantly between the two groups. Left and right cardiac chamber dimensions and ventricular and valvular function as evaluated by conventional Doppler parameters were also not significantly different. Right ventricular strain and strain rate were similar between the groups. However, right ventricular myocardial TDI systolic (Sa: 5.4+2 vs. 8.5 +/- 3, p = 0.004) and diastolic indices and velocities (Ea, Aa, septal E/Ea, and RV free wall tissue tracking) were significantly reduced in patients with arrhythmias compared to the control group. Multivariate linear regression analysis identified RV early diastolic velocity as the sole variable independently associated with arrhythmic history (RV Ea: 4.5 +/- 1 vs. 6.7 +/- 2 cm/s, p = 0.01). A cut-off for RV Ea of < 6.1 cm/s identified patients in the arrhythmic group with 86% sensitivity and 59% specificity (AUC = 0.8). CONCLUSIONS: Our results suggest that TDI may detect RV dysfunction in patients with apparently normal function as assessed by conventional echocardiographic parameters. Reduction in RV early diastolic velocity appears to be an early abnormality and is associated with occurrence of arrhythmic events. TDI may be useful in risk stratification of patients with repaired tetralogy of Fallot.

Analysis of Systems with Backlash and Impacts through the Describing Function

This paper analyses the dynamical properties of systems with backlash and impact phenomena based on the describing function method. The dynamics is illustrated using the Nyquist and Bode plots and the results are compared with those of standard models.

Adrenal function in 23 children with paracoccidioidomycosis

Adrenal involvement by Paracoccidioides brasiliensis was described at necropsies and in many clinical studies, but only in adults. Therefore, the aim of this study was to evaluate adrenal function in children with paracoccidioidomycosis. Twenty-three children with the systemic form of paracoccidioidomycosis were evaluated and divided in two Groups: Group A (n = 8) included children before treatment and Group B (n = 15) children after the end of treatment. Plasma cortisol (basal and after ACTH test), ACTH, renin activity, aldosterone, sodium and potassium were measured. They were within normal range in all cases, except for renin activity and aldosterone, which were elevated in some cases. Group A patients showed basal and post-ACTH cortisol levels significantly greater than Group B patients. The results showed that adrenal function was not compromised in these children with paracoccidioidomycosis.

Effects of Exercise on Physical and Mental Health, and Cognitive and Brain Functions in Schizophrenia: Clinical and Experimental Evidence

Exercise promotes several health benefits, such as cardiovascular, musculoskeletal and cardiorespiratory improvements. It is believed that the practice of exercise in individuals with psychiatric disorders, e.g. schizophrenia, can cause significant changes. Schizophrenic patients have problematic lifestyle habits compared with general population; this may cause a high mortality rate, mainly caused by cardiovascular and metabolic diseases. Thus, the aim of this study is to investigate changes in physical and mental health, cognitive and brain functioning due to the practice of exercise in patients with schizophrenia. Although still little is known about the benefits of exercise on mental health, cognitive and brain functioning of schizophrenic patients, exercise training has been shown to be a beneficial intervention in the control and reduction of disease severity. Type of training, form of execution, duration and intensity need to be better studied as the effects on physical and mental health, cognition and brain activity depend exclusively of interconnected factors, such as the combination of exercise and medication. However, one should understand that exercise is not only an effective nondrug alternative, but also acts as a supporting linking up interventions to promote improvements in process performance optimization. In general, the positive effects on mental health, cognition and brain activity as a result of an exercise program are quite evident. Few studies have been published correlating effects of exercise in patients with schizophrenia, but there is increasing evidence that positive and negative symptoms can be improved. Therefore, it is important that further studies be undertaken to expand the knowledge of physical exercise on mental health in people with schizophrenia, as well as its dose-response and the most effective type of exercise.

Seroconvertion to hepatitis B vaccine after weight reduction in obese non-responder

Decreased responses to hepatitis B vaccine have been associated with some host conditions including obesity. Susceptible non-responders to a primary three-dose vaccine series should be revaccinated. Those who maintain a non-responder condition after revaccination with three vaccine doses are unlikely to develop protection using more doses. This is a description of an obese woman who received six doses of hepatitis B vaccine and persisted as a non-responder. She was submitted to a vertical banded gastroplasty Roux-en-Y gastric bypass Capellas's technique. After weight reduction, she received three additional doses of vaccine and seroconverted. Further studies should help clarify the need to evaluate antibody levels and eventually revaccinate the increasing population of individuals who undergo weight reduction.

Postaerobic Exercise Blood Pressure Reduction in Very Old Persons With Hypertension.

BACKGROUND AND PURPOSE: A single bout of aerobic exercise acutely decreases blood pressure, even in older adults with hypertension. Nonetheless, blood pressure responses to aerobic exercise in very old adults with hypertension have not yet been documented. Therefore, this study aimed to assess the effect of a single session of aerobic exercise on postexercise blood pressure in very old adults with hypertension. METHODS: Eighteen older adults with essential hypertension were randomized into exercise (N = 9, age: 83.4 ± 3.2 years old) or control (N = 9, age: 82.7 ± 2.5 years old) groups. The exercise group performed a session of aerobic exercise constituting 2 periods of 10 minutes of walking at an intensity of 40% to 60% of the heart rate reserve. The control group rested for the same period of time. Anthropometric variables and medication status were evaluated at baseline. Heart rate and systolic and diastolic blood pressures were measured at baseline, after exercise, and at 20 and 40 minutes postexercise. RESULTS: Systolic blood pressure showed a significant interaction for group × time (F3,24 = 6.698; P = .002; ηp = 0.153). In the exercise group, the systolic blood pressure at 20 (127.3 ± 20.9 mm Hg) and 40 minutes (123.7 ± 21.0 mm Hg) postexercise was significantly lower in comparison with baseline (135.6 ± 20.6 mm Hg). Diastolic blood pressure did not change. Heart rate was significantly higher after the exercise session. In the control group, no significant differences were observed. CONCLUSIONS: A single session of aerobic exercise acutely reduces blood pressure in very old adults with hypertension and may be considered an important nonpharmacological strategy to control hypertension in this age group.

Prostatic Artery Embolization in the Treatment of Benign Prostatic Hyperplasia: Short and Medium Follow-Up

To evaluate the short and mid-term results of prostatic artery embolization in patients with benign prostatic embolization. Retrospective study between March 2009 and June 2011 with 103 patients (mean age 66.8 years, 50-85) that met our inclusion criteria with symptomatic benign prostatic hyperplasia. The clinical outcome was evaluated by the International Prostate Symptom Score (IPSS), quality of life (QoL), International Index of Erectile Function, prostate volume (PV), prostate-specific antigen (PSA), peak urinary flow (Q(max)), and post-void residual volume (PVR) measurements at 3 and 6 months, 1 year, 18 months, and 2 years after PAE and comparison with baseline values was made. Technical and clinical successes, as well as poor clinical outcome definitions, were previously defined. In this review, we evaluate the short and mid-term clinical outcomes and morbidity of patients treated only with non-spherical polyvinyl alcohol. Six months after the procedure, the PV decreased about 23%, IPSS changed to a mean value of 11.95 (almost 50% reduction), the QoL improved slightly more than 2 points, the Q(max) changed to a mean value of 12.63mL/s, the PVR underwent a change of almost half of the baseline value, and the PSA decreased about 2.3ng/mL. In the mid-term follow-up and comparing to the baseline values, we still assisted to a reduction in PV, IPSS, QoL, PVR, and PSA, and an increase in Q(max). Prostatic Artery Embolization is a safe procedure with low morbidity that shows good short- and mid-term clinical outcome in our institution.

Zero-Time Kidney Histology Predicts Early Graft Function

Our purposes are to determine the impact of histological factors observed in zero-time biopsies on early post transplant kidney allograft function. We specifically want to compare the semi-quantitative Banff Classification of zero time biopsies with quantification of % cortical area fibrosis. Sixty three zero-time deceased donor allograft biopsies were retrospectively semiquantitatively scored using Banff classification. By adding the individual chronic parameters a Banff Chronic Sum (BCS) Score was generated. Percentage of cortical area Picro Sirius Red (%PSR) staining was assessed and calculated with a computer program. A negative linear regression between %PSR/ GFR at 3 year post-transplantation was established (Y=62.08 +-4.6412X; p=0.022). A significant negative correlation between arteriolar hyalinosis (rho=-0.375; p=0.005), chronic interstitial (rho=0.296; p=0.02) , chronic tubular ( rho=0.276; p=0.04) , chronic vascular (rho= -0.360;P=0.007), BCS (rho=-0.413; p=0.002) and GFR at 3 years were found. However, no correlation was found between % PSR, Ci, Ct or BCS. In multivariate linear regression the negative predictive factors of 3 years GFR were: BCS in histological model; donor kidney age, recipient age and black race in clinical model. The BCS seems a good and easy to perform tool, available to every pathologist, with significant predictive short-term value. The %PSR predicts short term kidney function in univariate study and involves extra-routine and expensive-time work. We think that %PSR must be regarded as a research instrument.