Total and segmental colonic transit time in constipated patients with Chagas’ disease without megaesophagus or megacolon

Manometric and pharmacological tests have shown that motor abnormalities may occur in the non-dilated colons of chagasic patients. In order to investigate the presence of abnormalities of colonic function in constipated patients with Chagas’ disease (ChC) without megaesophagus or megacolon, studies of total and segmental colonic transit time with radiopaque markers were performed on 15 ChC patients, 27 healthy volunteers and 17 patients with idiopathic constipation (IC). The values obtained for the control group were similar to those reported in the literature (total colonic time: 34.1 ± 15.6 h; right colon: 9.9 ± 7.3 h; left colon: 10.8 ± 10 h, and rectosigmoid: 12.6 ± 9.9 h). Colonic transit time data permitted us to divide both IC and ChC patients into groups with normal transit and those with slow colonic transit. Colonic inertia was detected in 41% of IC patients and in 13% of ChC patients; left colon isolated stasis (hindgut dysfunction) was detected in 12% of IC patients and 7% of ChC patients, and outlet obstruction was detected in 6% of IC patients and 7% of ChC patients. There were no significant differences in total or segmental colonic transit times between slow transit IC and slow transit ChC patients. In conclusion, an impairment of colonic motility was detected in about 30% of constipated patients with Chagas’ disease without megaesophagus or megacolon. This subgroup of patients presented no distinctive clinical feature or pattern of colonic dysmotility when compared to patients with slow transit idiopathic constipation.

Automated grading of left ventricular segmental wall motion by an artificial neural network using color kinesis images

The present study describes an auxiliary tool in the diagnosis of left ventricular (LV) segmental wall motion (WM) abnormalities based on color-coded echocardiographic WM images. An artificial neural network (ANN) was developed and validated for grading LV segmental WM using data from color kinesis (CK) images, a technique developed to display the timing and magnitude of global and regional WM in real time. We evaluated 21 normal subjects and 20 patients with LVWM abnormalities revealed by two-dimensional echocardiography. CK images were obtained in two sets of viewing planes. A method was developed to analyze CK images, providing quantitation of fractional area change in each of the 16 LV segments. Two experienced observers analyzed LVWM from two-dimensional images and scored them as: 1) normal, 2) mild hypokinesia, 3) moderate hypokinesia, 4) severe hypokinesia, 5) akinesia, and 6) dyskinesia. Based on expert analysis of 10 normal subjects and 10 patients, we trained a multilayer perceptron ANN using a back-propagation algorithm to provide automated grading of LVWM, and this ANN was then tested in the remaining subjects. Excellent concordance between expert and ANN analysis was shown by ROC curve analysis, with measured area under the curve of 0.975. An excellent correlation was also obtained for global LV segmental WM index by expert and ANN analysis (R² = 0.99). In conclusion, ANN showed high accuracy for automated semi-quantitative grading of WM based on CK images. This technique can be an important aid, improving diagnostic accuracy and reducing inter-observer variability in scoring segmental LVWM.

Minor segmental wall motion abnormalities detected in patients with Chagas' disease have adverse prognostic implications

Recent data from our laboratory have shown that patients with the indeterminate form of Chagas' disease can have impairment of left ventricular contractility, as evaluated by the slope of the left ventricle end-systolic pressure-dimension relationship. We also showed that Chagas' disease patients with minimal baseline wall motion abnormalities detected by two-dimensional echocardiography have more intense contractility impairment when compared to patients with the indeterminate form of the disease without this abnormality. The prognostic implications of these findings have not been established. We evaluated 59 patients (37-76 years, mean = 55 years) with different clinical forms of Chagas' disease, who had normal left ventricular global systolic function at baseline (57.6 ± 6.9%) and who had at least one additional echo during clinical follow-up (0.4-17.6; mean 4.6 years). Group 1 consisted of 14 patients with minor baseline left ventricle wall motion abnormalities and group 2 consisted of 45 patients without these abnormalities. During follow-up, global left ventricle systolic function deterioration was observed in 10 group 1 patients (71.4%) and in only 10 group 2 patients (22.2%; P < 0.005). Age and duration of follow-up were not independent determinants of left ventricular function deterioration in these patients. The present data indicate that mild segmental left ventricular wall motion abnormalities are associated with worsening of systolic function in Chagas' disease patients who have normal baseline global systolic performance.

Local Binary Patterns in Focal-Plane Processing. Analysis and Applications

Feature extraction is the part of pattern recognition, where the sensor data is transformed into a more suitable form for the machine to interpret. The purpose of this step is also to reduce the amount of information passed to the next stages of the system, and to preserve the essential information in the view of discriminating the data into different classes. For instance, in the case of image analysis the actual image intensities are vulnerable to various environmental effects, such as lighting changes and the feature extraction can be used as means for detecting features, which are invariant to certain types of illumination changes. Finally, classification tries to make decisions based on the previously transformed data. The main focus of this thesis is on developing new methods for the embedded feature extraction based on local non-parametric image descriptors. Also, feature analysis is carried out for the selected image features. Low-level Local Binary Pattern (LBP) based features are in a main role in the analysis. In the embedded domain, the pattern recognition system must usually meet strict performance constraints, such as high speed, compact size and low power consumption. The characteristics of the final system can be seen as a trade-off between these metrics, which is largely affected by the decisions made during the implementation phase. The implementation alternatives of the LBP based feature extraction are explored in the embedded domain in the context of focal-plane vision processors. In particular, the thesis demonstrates the LBP extraction with MIPA4k massively parallel focal-plane processor IC. Also higher level processing is incorporated to this framework, by means of a framework for implementing a single chip face recognition system. Furthermore, a new method for determining optical flow based on LBPs, designed in particular to the embedded domain is presented. Inspired by some of the principles observed through the feature analysis of the Local Binary Patterns, an extension to the well known non-parametric rank transform is proposed, and its performance is evaluated in face recognition experiments with a standard dataset. Finally, an a priori model where the LBPs are seen as combinations of n-tuples is also presented

The effect of focal point parameters in fiber laser welding of structural steel

In this thesis the effect of focal point parameters in fiber laser welding of structural steel is studied. The goal is to establish relations between laser power, focal point diameter and focal point position with the resulting quality, weld-bead geometry and hardness of the welds. In the laboratory experiments, AB AH36 shipbuilding steel was welded in an I-butt joint configuration using IPG YLS-10000 continuous wave fiber laser. The quality of the welds produced were evaluated based on standard SFS-EN ISO 13919-1. The weld-bead geometry was defined from the weld cross-sections and Vickers hardness test was used to measure hardness's from the middle of the cross-sections. It was shown that all the studied focal point parameters have an effect on the quality, weld-bead geometry and hardness of the welds produced.

Hyperthermia induced after recirculation triggers chronic neurodegeneration in the penumbra zone of focal ischemia in the rat brain

Chronic neurodegenerative processes have been identified in the rat forebrain after prolonged survival following hyperthermia (HT) initiated a few hours after transient global ischemia. Since transient global ischemia and ischemic penumbra share pathophysiological similarities, this study addressed the effects of HT induced after recirculation of focal brain ischemia on infarct size during long survival times. Adult male Wistar rats underwent intra-luminal occlusion of the left middle cerebral artery for 60 min followed by HT (39.0-39.5°C) or normothermia. Control procedures included none and sham surgery with and without HT, and middle cerebral artery occlusion alone. Part I: 6-h HT induced at recirculation. Part II: 2-h HT induced at 2-, 6-, or 24-h recirculation. Part III: 2-h HT initiated at recirculation or 6-h HT initiated at 2-, 6- or 24-h recirculation. Survival periods were 7 days, 2 or 6 months. The effects of post-ischemic HT on cortex and striatum were evaluated histopathologically by measuring the area of remaining tissue in the infarcted hemisphere at -0.30 mm from bregma. Six-hour HT initiated from 6-h recirculation caused a significant decrease in the remaining cortical tissue between 7-day (N = 8) and 2-month (N = 8) survivals (98.46 ± 1.14 to 73.62 ± 8.99%, respectively). When induced from 24-h recirculation, 6-h HT caused a significant reduction of the remaining cortical tissue between 2- (N = 8) and 6-month (N = 9) survivals (94.97 ± 5.02 vs 63.26 ± 11.97%, respectively). These data indicate that post-ischemic HT triggers chronic neurodegenerative processes in ischemic penumbra, suggesting that similar fever-triggered effects may annul the benefit of early recirculation in stroke patients over the long-term.

Focal adhesion kinase signaling in cardiac hypertrophy and failure

Focal adhesion kinase (FAK) is a broadly expressed tyrosine kinase implicated in cellular functions such as migration, growth and survival. Emerging data support a role for FAK in cardiac development, reactive hypertrophy and failure. Data reviewed here indicate that FAK plays a critical role at the cellular level in the responses of cardiomyocytes and cardiac fibroblasts to biomechanical stress and to hypertrophic agonists such as angiotensin II and endothelin. The signaling mechanisms regulated by FAK are discussed to provide insight into its role in the pathophysiology of cardiac hypertrophy and failure.

Variantes histológicas da glomeruloesclerose segmentar e focal primária: casuística e evolução clínica

INTRODUÇÃO: O significado clínico das variantes histológicas da glomeruloesclerose segmentar e focal primária (GESF) ainda é pouco claro. Com o objetivo de determinar a frequência das variantes da GESF e sua evolução clínica em uma população hispânica, analisamos nossos casos desta glomerulopatia. MÉTODOS: Neste estudo retrospectivo, biópsias renais com diagnóstico de GESF (de 1998 a 2009) foram analisadas e classificadas acordo com os critérios da classificação de Columbia. Os dados clínico-evolutivos foram analisados e comparados entre as variantes. RESULTADOS: Do total de 291 casos, 224 (77,0%) corresponderam a variante sem especificação (NOS), 40 casos (13,7%) a forma com lesão no polo urinário (TIP), 14 casos (4,8%) a lesão perihiliar (PH), 10 casos (3,4%) ao tipo colapsante (COLL) e três casos (1,0%) a variante celular (CEL). A idade média de apresentação foi de 26 anos (intervalo de 1 a 79), sendo 74 pacientes (25,4%) com idade inferior a 15 anos. Hipertensão arterial e disfunção renal foram os achados mais frequentes nos casos de PH e COLL. A variante PH apresentou-se, frequentemente, com proteinúria não nefrótica. Notou-se menos lesões histológicas de cronicidade em casos TIP. Houve remissão clínica em 57% dos pacientes com TIP, 23,5% dos pacientes com NOS, 22,2% dos pacientes com COLL e em nenhum paciente com PH (p < 0,01). Doença renal crônica (DRC) foi menos frequente no grupo TIP comparativamente as outras variantes (p = 0,03). Não houve diferença estatística na evolução para estágio final da doença renal entre as variantes. CONCLUSÕES: A aparência histológica não parece ser um bom marcador clínico de prognóstico na GESF. A forma COLL é uma doença com muitas diferenças para as outras variantes e pior prognóstico. A variante PH ocorre principalmente de adultos, com evolução frequente para DRC. A lesão do tipo TIP parece ser menos agressiva que as outras variantes, embora sua evolução não seja benigna.

Glomeruloesclerose segmentar e focal (GESF) colapsante associada ao parvovírus B19: relato de caso

Objetivo: Descrever quadro clínico-laboratorial de glomeruloesclerose segmentar e focal (GESF) subtipo colapsante em associação com infecção por parvovírus B19 (PVB19). Relato do caso: Paciente feminino, 37 anos, parda, iniciou quadro de faringoalgia e febre aferida com melhora parcial após penicilina. Com uma semana, observou redução de débito urinário e edema de membros inferiores. Tabagista, com histórico familiar e pessoal negativos para hipertensão, diabetes ou nefropatias. À admissão, apresentava-se com oliguria, hipertensão e edema, associados à anemia microcítica e hipocrômica hipoproliferativa, proteinúria nefrótica, hematúria microscópica e alteração da função renal. A investigação reumatológica e sorologias para hepatites e HIV foram negativas. Ultrassonografia de rins e vias urinárias sem alterações. PCR foi positivo para PVB19 em aspirado de medula óssea e sangue. A biópsia renal conclusiva de GESF subtipo colapsante. Ocorreu remissão espontânea com duas semanas do quadro. Em retorno ambulatorial, o PCR em sangue periférico foi negativo para PVB19, sugerindo associação de GESF colapsante a fase aguda ou reativação da infecção viral. Conclusão : Este relato registra a associação temporal entre GESF colapsante e viremia pelo PVB19, seja por infecção aguda ou reativação de infecção latente. A associação GESF colapsante e PVB19 é descrita na literatura, com demonstração da presença do vírus em tecido renal, porém, a real relação do vírus na patogênese dessa glomerulopatia permanece indefinida.

Doença de lesões mínimas e glomeruloesclerose segmentar e focal em adultos: resposta a corticoide e risco de insuficiência renal

Resumo Introdução: O perfil clínico de pacientes brasileiros adultos com síndrome nefrótica por doença de lesões mínimas (LM) e glomeruloesclerose segmentar e focal (GESF) é pouco conhecido. Objetivo: Avaliamos as características clínico-laboratoriais e resposta a tratamento em pacientes adultos com síndrome nefrótica e diagnósticos histológicos de LM ou GESF. Métodos: Fez-se a análise retrospectiva de 50 pacientes adultos com LM e 120 com GESF. Todos os pacientes foram inicialmente tratados com corticosteroide. Os desfechos do estudo foram: resposta a corticosteroide, prevalência de remissão total, progressão para doença renal crônica estágio 5 (DRC5) e necessidade de terapia de substituição renal por DRC5. Resultados: Níveis iniciais de creatinina sérica foram 24% mais elevados entre pacientes com GESF (p = 0,02) e os de proteinúria foram 36% mais altos em LM (p < 0,001). Pacientes com LM foram córtico-sensíveis em 80% dos casos, com remissão total em 74%, e os pacientes com GESF em 58% (p = 0,01), com remissão total em 30% (p = 0,002). A prevalência de insuficiência renal aguda em pacientes com GESF foi de 39% (vs. 12%, p = 0,013) e DRC5 de 10% (vs. 0%, p < 0,001). Remissão completa ou parcial com o uso de corticosteroide reduziu em 83% o risco de DRC5 (p < 0,001) e remissão total associou-se a redução no risco de DRC5 de 89% (p < 0,001). Conclusão: A resposta positiva à corticoterapia foi o fator mais importante relacionado à preservação da função renal ao longo de mais de uma década de seguimento, e GESF relacionou-se a menor índice de resposta a corticosteroide.

The effect of a segmental, localized lower limb cooling protocol on muscular strength and balance

The human neuromuscular system is susceptible to changes within the thermal environment. Cold extrinsic temperatures can significantly reduce muscle and nervous system function and communication, which can have consequences for motor performance. A repeated measures design protocol exposed participants to a 12°C cold water immersion (CWI) up to the ankle, knee, and hip to determine the effect that reduced skin and muscle temperature had on balance and strength task execution. Although a linear reduction in the ability to perform balance tasks was seen from the control condition through to the hip CWI, results from the study indicated a significant reduction in dynamic balance (Star Excursion Balance Test reach distance) performance from only the hip CWI (P<0.05). This reduced performance could have been due to an increase in joint stiffness, increased agonist-antagonist co-contraction, and/or reduced isokinetic muscular strength. Reduced physical performance due to cold temperature could negatively impact outdoor recreational athletics.

Planeación punto focal de la auditoría financiera por Manuel Coello Ríos

Tesis [Maestría en Contaduría Pública con Especialidad en Auditoría) U.A.N.L.

fNIRS-EEG study of focal interictal epileptiform discharges

Functional near-infrared spectroscopy (fNIRS) acquired with electroencephalography (EEG) is a relatively new non-invasive neuroimaging technique with potential for long term monitoring of the epileptic brain. Simultaneous EEG-fNIRS recording allows the spatio-temporal reconstruction of the hemodynamic response in terms of the concentration changes in oxy-hemoglobin (HbO) and deoxy-hemoglobin (HbR) associated with recorded epileptic events such as interictal epileptic discharges (IEDs) or seizures. While most previous studies investigating fNIRS in epilepsy had limitations due to restricted spatial coverage and small sample sizes, this work includes a sufficiently large number of channels to provide an extensive bilateral coverage of the surface of the brain for a sample size of 40 patients with focal epilepsies. Topographic maps of significant activations due to each IED type were generated in four different views (dorsal, frontal, left and right) and were compared with the epileptic focus previously identified by an epileptologist. After excluding 5 patients due to the absence of IEDs and 6 more with mesial temporal foci too deep for fNIRS, we report that significant HbR (respectively HbO) concentration changes corresponding to IEDs were observed in 62% (resp. 38%) of patients with neocortical epilepsies. This HbR/HbO response was most significant in the epileptic focus region among all the activations in 28%/21% of patients.

Especificidad de la relación entre la conciencia segmental y el aprendizaje de la lecto-escritura en la dislexia.

Buscar cuál es la importancia del aprendizaje lecto-escritor en la relación establecida por los niños entre el lenguaje escrito y el oral a nivel fonológico, como base de la hipótesis: los problemas lecto-escritores de los niños disléxicos provocados por la falta de desarrollo de la conciencia segmental. Estudiar que muestran una clara oposición a una instrucción que mejore su aprendizaje. Población: tres colegios públicos de Salamanca. Niveles segundo y tercero de EGB. 8 Niños, 4 varones de CI medio-bajo (DX) y 4 disléxicos de CI normal (RT). Estudio teórico sobre el aprendizaje de la lecto-escritura. Destaca la importancia del procesamiento fonológico y la conciencia segmental. Establece un relación bidireccional entre la conciencia segmental y el aprendizaje de la lecto-escritura. Deja teóricamente demostrado que el entrenamiento en tareas que desarrollan la conciencia segmental favorece el aprendizaje de la lectura, siendo de importancia para los niños disléxicos cuya dificultad se debe a la falta de este desarrollo. Hace una detallada fundamentación teórica: Bradley y Brayant (1978) sobre la dislexia proponiendo el modelo de adquisición de la lectura de Uta Frith como soporte teórico de su hipótesis. Utiliza el programa 'Escribir una palabra' (Sánchez, Rueda y Orrantía 1989) como entrenamiento de la conciencia segmental. Programa basado en el concepto de resistencia a la instrucción ligado al concepto de interacción de Vygotski (1979). Selección: WISC. Tale (análisis de la lectura y la escritura). Cuestionario para medir el nivel de metalenguaje (Rueda y Sánchez,1988). Intervención: programa de instrucción, hoja de ayudas y lista de palabras o pseudopalabras. Diseño experimental. ANOVA de un factor. Análisis particular de cada uno de los ocho casos. 'Escribir una palabra'. Los niños DX necesitaron mayor número de ayudas específicas a la conciencia segmental cuando tenían que realizar aquellos pasos del programa que suponen segmentación de los fonos. No aparecen diferencias importantes en cuanto a ayudas necesarias en las categorías de colaboración y uso del código. Los niños del grupo RT no necesitan mayor número de ayudas no específicas que los disléxicos. El problema de los niños disléxicos es que no son capaces de segmentar cuando se les instruye para hacerlo, presentan resistencia a la instrucción por ello, debe insistirse en el desarrollo de la conciencia segmental, pues es la pieza clave para el aprendizaje lectoescritor, de extrema importancia pues es lo que permite acceder al niño al conocimiento.