Schistosomiasis: A neglected cause of pulmonary arterial hypertension in Brazil.

Schistosomiasis is a prevalent disease in Brazil whose etiological agent is Schistosoma mansoni, the main species associated with pulmonary arterial hypertension (PAH), a serious complication. It is estimated that this complication affects up to 15% of patients with the hepatosplenic form of the disease. Despite being an endemic country, Brazil does not have a screening scheme for cases of PAH associated with schistosomiasis (PAH-Sch), nor protocols for notification and treatment of this vascular complication. The objectives of this literature review are to gather knowledge about the pathophysiology, clinical manifestations, diagnosis and treatment of PAH-Sch and to highlight relevant aspects for the Brazilian reality. The pathophysiology, although lacking information, has proliferative vasculopathy as a central element. The clinical presentation of this disease can be asymptomatic or with nonspecific manifestations. Thus, complementary exams are essential for a confirmatory diagnosis, the gold standard being right heart catheterization, a scarce resource in endemic regions of the country. The treatment of PAH-Sch is similar to that performed for other causes of PAH, but the impact of anthelmintic therapy on the evolution of the vascular pathology is unknown. Therefore, Brazil needs to develop a screening plan for early diagnosis of PAH-Sch and new studies should be carried out to determine a more specific treatment.

Sudden cardiac death multiparametric classification system for Chagas heart disease's patients based on clinical data and 24-hours ECG monitoring.

About 6.5 million people are infected with Chagas disease (CD) globally, and WHO estimates that $ > million people worldwide suffer from ChHD. Sudden cardiac death (SCD) represents one of the leading causes of death worldwide and affects approximately 65% of ChHD patients at a rate of 24 per 1000 patient-years, much greater than the SCD rate in the general population. Its occurrence in the specific context of ChHD needs to be better exploited. This paper provides the first evidence supporting the use of machine learning (ML) methods within non-invasive tests: patients' clinical data and cardiac restitution metrics (CRM) features extracted from ECG-Holter recordings as an adjunct in the SCD risk assessment in ChHD. The feature selection (FS) flows evaluated 5 different groups of attributes formed from patients' clinical and physiological data to identify relevant attributes among 57 features reported by 315 patients at HUCFF-UFRJ. The FS flow with FS techniques (variance, ANOVA, and recursive feature elimination) and Naive Bayes (NB) model achieved the best classification performance with 90.63% recall (sensitivity) and 80.55% AUC. The initial feature set is reduced to a subset of 13 features (4 Classification; 1 Treatment; 1 CRM; and 7 Heart Tests). The proposed method represents an intelligent diagnostic support system that predicts the high risk of SCD in ChHD patients and highlights the clinical and CRM data that most strongly impact the final outcome.

Effects of lumbar myelography on subarachnoid pressure and cardiorespiratory parameters in healthy sheep / Efeitos da mielografia lombar na pressão subaracnoidea e nos parâmetros cardiorrespiratórios em ovelhas saudáveis

The purpose of this study was to evaluate the effects of lumbar myelography on subarachnoid pressure, cardiorespiratory parameters and pressure-volume index in sheep. Eight sheep were evaluated. The animals were submitted to puncture of the cisterna magna for monitoring of subarachnoid pressure (SaP). Lumbar myelography was performed through applying Iohexol (0.4mL/kg). ToC, PAS, PAD, MAP, InspISO, FeISO, SaP and CPP were recorded immediately after anesthetic stabilization (M0), during lumbar puncture (M1), and two, four and six minutes after contrast application (M2, M3 and M4, respectively). Blood pressure initially increased, then decreased, returning to basal level, similarly observed for InspISo and FeISo. The SaP rose initially thereafter remaining stable. Despite of the effect on subarachnoid pressure, lumbar myelography can be considered safe in sheep.(AU)

O objetivo foi avaliar os efeitos da mielografia lombar na pressão subaracnóidea, parâmetros cardiorrespiratórios e índice pressão-volume em ovinos. Oito ovelhas foram avaliadas. Os animais foram submetidos à punção da cisterna magna para monitoramento da pressão subaracnoidea (SaP). A mielografia lombar foi realizada com a aplicação de Iohexol (0,4mL/kg). Os momentos estudados foram: imediatamente após a estabilização anestésica (M0), durante a punção lombar (M1), dois, quatro e seis minutos após a aplicação do contraste (M2, M3 e M4, respectivamente), para avaliar as seguintes variáveis: ToC, PAS, PAD, MAP, InspISO, FeISO, Sap e CPP. A pressão arterial aumentou inicialmente, depois diminuiu, retornando aos valores iniciais, padrão também observado para o InspISo e o FeISo. O SaP subiu inicialmente, posteriormente, permanecendo estável. A mielografia lombar, apesar de influenciar a pressão subaracnoidea, pode ser considerada segura em ovinos.(AU)

Effects of lumbar myelography on subarachnoid pressure and cardiorespiratory parameters in healthy sheep

ABSTRACT: The purpose of this study was to evaluate the effects of lumbar myelography on subarachnoid pressure, cardiorespiratory parameters and pressure-volume index in sheep. Eight sheep were evaluated. The animals were submitted to puncture of the cisterna magna for monitoring of subarachnoid pressure (SaP). Lumbar myelography was performed through applying Iohexol (0.4mL/kg). ToC, PAS, PAD, MAP, InspISO, FeISO, SaP and CPP were recorded immediately after anesthetic stabilization (M0), during lumbar puncture (M1), and two, four and six minutes after contrast application (M2, M3 and M4, respectively). Blood pressure initially increased, then decreased, returning to basal level, similarly observed for InspISo and FeISo. The SaP rose initially thereafter remaining stable. Despite of the effect on subarachnoid pressure, lumbar myelography can be considered safe in sheep.

RESUMO: O objetivo foi avaliar os efeitos da mielografia lombar na pressão subaracnóidea, parâmetros cardiorrespiratórios e índice pressão-volume em ovinos. Oito ovelhas foram avaliadas. Os animais foram submetidos à punção da cisterna magna para monitoramento da pressão subaracnoidea (SaP). A mielografia lombar foi realizada com a aplicação de Iohexol (0,4mL/kg). Os momentos estudados foram: imediatamente após a estabilização anestésica (M0), durante a punção lombar (M1), dois, quatro e seis minutos após a aplicação do contraste (M2, M3 e M4, respectivamente), para avaliar as seguintes variáveis: ToC, PAS, PAD, MAP, InspISO, FeISO, Sap e CPP. A pressão arterial aumentou inicialmente, depois diminuiu, retornando aos valores iniciais, padrão também observado para o InspISo e o FeISo. O SaP subiu inicialmente, posteriormente, permanecendo estável. A mielografia lombar, apesar de influenciar a pressão subaracnoidea, pode ser considerada segura em ovinos.

Effects of lumbar myelography on subarachnoid pressure and cardiorespiratory parameters in healthy sheep / Efeitos da mielografia lombar na pressão subaracnoidea e nos parâmetros cardiorrespiratórios em ovelhas saudáveis

The purpose of this study was to evaluate the effects of lumbar myelography on subarachnoid pressure, cardiorespiratory parameters and pressure-volume index in sheep. Eight sheep were evaluated. The animals were submitted to puncture of the cisterna magna for monitoring of subarachnoid pressure (SaP). Lumbar myelography was performed through applying Iohexol (0.4mL/kg). ToC, PAS, PAD, MAP, InspISO, FeISO, SaP and CPP were recorded immediately after anesthetic stabilization (M0), during lumbar puncture (M1), and two, four and six minutes after contrast application (M2, M3 and M4, respectively). Blood pressure initially increased, then decreased, returning to basal level, similarly observed for InspISo and FeISo. The SaP rose initially thereafter remaining stable. Despite of the effect on subarachnoid pressure, lumbar myelography can be considered safe in sheep.(AU)

O objetivo foi avaliar os efeitos da mielografia lombar na pressão subaracnóidea, parâmetros cardiorrespiratórios e índice pressão-volume em ovinos. Oito ovelhas foram avaliadas. Os animais foram submetidos à punção da cisterna magna para monitoramento da pressão subaracnoidea (SaP). A mielografia lombar foi realizada com a aplicação de Iohexol (0,4mL/kg). Os momentos estudados foram: imediatamente após a estabilização anestésica (M0), durante a punção lombar (M1), dois, quatro e seis minutos após a aplicação do contraste (M2, M3 e M4, respectivamente), para avaliar as seguintes variáveis: ToC, PAS, PAD, MAP, InspISO, FeISO, Sap e CPP. A pressão arterial aumentou inicialmente, depois diminuiu, retornando aos valores iniciais, padrão também observado para o InspISo e o FeISo. O SaP subiu inicialmente, posteriormente, permanecendo estável. A mielografia lombar, apesar de influenciar a pressão subaracnoidea, pode ser considerada segura em ovinos.(AU)

New approach for T-wave peak detection and T-wave end location in 12-lead paced ECG signals based on a mathematical model.

This paper presents an innovative approach for T-wave peak detection and subsequent T-wave end location in 12-lead paced ECG signals based on a mathematical model of a skewed Gaussian function. Following the stage of QRS segmentation, we establish search windows using a number of the earliest intervals between each QRS offset and subsequent QRS onset. Then, we compute a template based on a Gaussian-function, modified by a mathematical procedure to insert asymmetry, which models the T-wave. Cross-correlation and an approach based on the computation of Trapezium's area are used to locate, respectively, the peak and end point of each T-wave throughout the whole raw ECG signal. For evaluating purposes, we used a database of high resolution 12-lead paced ECG signals, recorded from patients with ischaemic cardiomyopathy (ICM) in the University Hospitals of Leicester NHS Trust, UK, and the well-known QT database. The average T-wave detection rates, sensitivity and positive predictivity, were both equal to 99.12%, for the first database, and, respectively, equal to 99.32% and 99.47%, for QT database. The average time errors computed for T-wave peak and T-wave end locations were, respectively, -0.38±7.12 ms and -3.70±15.46 ms, for the first database, and 1.40±8.99 ms and 2.83±15.27 ms, for QT database. The results demonstrate the accuracy, consistency and robustness of the proposed method for a wide variety of T-wave morphologies studied.

An innovative approach of QRS segmentation based on first-derivative, Hilbert and Wavelet Transforms.

The QRS detection and segmentation processes constitute the first stages of a greater process, e.g., electrocardiogram (ECG) feature extraction. Their accuracy is a prerequisite to a satisfactory performance of the P and T wave segmentation, and also to the reliability of the heart rate variability analysis. This work presents an innovative approach of QRS detection and segmentation and the detailed results of the proposed algorithm based on First-Derivative, Hilbert and Wavelet Transforms, adaptive threshold and an approach of surface indicator. The method combines the adaptive threshold, Hilbert and Wavelet Transforms techniques, avoiding the whole ECG signal preprocessing. After each QRS detection, the computation of an indicator related to the area covered by the QRS complex envelope provides the detection of the QRS onset and offset. The QRS detection proposed technique is evaluated based on the well-known MIT-BIH Arrhythmia and QT databases, obtaining the average sensitivity of 99.15% and the positive predictability of 99.18% for the first database, and 99.75% and 99.65%, respectively, for the second one. The QRS segmentation approach is evaluated on the annotated QT database with the average segmentation errors of 2.85±9.90ms and 2.83±12.26ms for QRS onset and offset, respectively. Those results demonstrate the accuracy of the developed algorithm for a wide variety of QRS morphology and the adaptation of the algorithm parameters to the existing QRS morphological variations within a single record.

Fluorimetric determination of cyclofenil using photochemical derivatization.

In this work, a fluorimetric approach for the determination of cyclofenil, 4-4'-(cyclohexylidenemethylene)bis(phenylacetate), is presented. The method was based on the intense fluorescence (250/410 nm) observed after a UV photochemical treatment of cyclofenil. The influence of the pH and solvent system and UV exposure time on the fluorescence magnitude was studied. Optimization of parameters was made using experimental design (factorial design and central composite design). Limit of detection (3S(b)/m) were estimated to be 1.1 x 10(-8)mol L(-1) with the linear dynamic range extending up to 8 x 10(-5)mol L(-1). This analytical approach was tested through the analysis of a commercial pharmaceutical formulation. In this case, tests enabled an average recovery of 98.3+/-3.9% (for n=9) using the analytical curve. The identification of the fluorescent derivative is proposed based on results achieved from GC-MS.