Lucas Ferrari de Oliveira

Pontine activation during focal status epilepticus secondary to hamartoma of the floor of the fourth ventricle

Epileptic seizures associated with hamartoma of the floor of the fourth ventricle (HFFV) are generally resistant to antiepileptic medication, may evolve into status epilepticus, and can respond favorably to surgical therapy. HFFV are rare, and during the neonatal or infantile period may be associated with repetitive and stereotyped attacks of hemifacial spasm, eye blinking, facial movements, head deviation and dysautonomic manifestations. Similarly, to gelastic seizures provoked by hypothalamic hamartomas, it has been suggested that these spells arise from within the HFFV, thus constituting a type of non-cortical seizure. We report an infant female patient that developed continuous left hemifacial attacks since she was 2-month-old, and that underwent presurgical investigation when she was 18-month-old. MRI disclosed a left sided HFFV, Video-EEG showed non-localizing and non-lateralizing findings, and SPECT aligned with MRI showed marked hyperperfusion within the hamartoma, spreading to ipsilateral cerebellar parenchyma and brainstem nuclei. Patient underwent lesionectomy and became seizure-free. We found two evidences on literature supporting the hypothesis of non-cortical seizures related to HFFV. The first, intra-cerebellar recordings surrounding hamartoma showed electrical activity related to seizures. The second, subtracted SPECT co-registered MRI showed hyperemia within hamartoma. The present report provides the third additional evidence. We found the involvement not only of the hamartoma, and pars of cerebellar hemisphere, but also an intense hyperemia involving brainstem nuclei during seizures. We believe that all these findings suggest a short subcortical network responsible for generating seizures in HFFV patients.

Draft genome sequence of the nitrogen-fixing symbiotic bacterium Bradyrhizobium elkanii 587.

The draft sequence of the genome of Bradyrhizobium elkanii 587 is presented. This was obtained using Illumina Next-Gen DNA sequencing combined with Sanger sequencing. Genes for the pathways involved in biological nitrogen fixation (the nif gene cluster), nod genes including nodABC, and genes for the type III protein secretion system (T3SS) are present.

Interictal hyperemia correlates with epileptogenicity in polymicrogyric cortex

OBJECTIVE To investigate pathophysiological factors underlying the presence of interictal hyperperfusion within the limits of the polymicrogyric (PMG) cortex in epileptic patients. METHODS Retrospective observational study on interictal perfusion by Single Photon Emission Computed Tomography (SPECT) in 16 patients with PMG and its correlations with a number of clinical and neurophysiological variables. Patients underwent video-EEG monitoring, neurological and psychiatric assessments, invasive EEG, and the interictal SPECT coregistered to Magnetic Resonance Imaging (MRI). RESULTS Patients with interictal hyperperfusion within the PMG cortex had a significantly higher spike rate on interictal EEG than patients with normal perfusion. Interictal hyperperfusion was not correlated to sex, age at epilepsy onset, age at evaluation, number of seizures per month, presence of initial precipitating insult (IPI), abnormal neurological examination, EEG findings, ictal semiology, and seizure outcome. The high interictal spike rate did not correlate to a high frequency of seizures per month. CONCLUSIONS Our work provides further evidences for an intrinsic epileptogenesis of the PMG cortex during the interictal state, which accounts for the major role of PMG tissue in seizure generation. These results might help to increase our understanding about epileptogenesis related to the PMG cortex, providing new tools for more tailored epilepsy surgery in PMG patients.

Characterization of the apical aneurysm of chronic chagas' heart disease by scintigraphic image co-registration

.Recent clinical trials have shown that the presence of this cardiac lesion is an independent risk factor for cardioembolic stroke in patients with chronic Chagas’ heart disease 3-5 . Therefore, early detection of the aneurysm using several diagnostic imaging methods is clinically relevant because of its therapeutic implications. ECG-gated SPECT myocardial perfusion imaging has been recently validated for assessing left ventricular function, and is now widely used 6 . Visual analysis of tomographic slices displayed in cine mode allows the identification of dyskinetic areas, including left ventricle aneurysms, associated with ischemic heart disease 7 . Nevertheless, while many Chagasic patients undergo myocardial perfusion imaging due to symptoms suggestive of myocardial ischemia, there is no report on characterization of the apical aneurysm of chronic Chagas’ disease by gated-SPECT. Multi-gated blood pool SPECT (MUGA-SPECT), which produces images of the ventricular cavity, and gated-SPECT (which produces images of the ventricular walls) provide complementary information for better characterization of this form of ventricular lesion in chronic Chagas’ heart disease. Recent computational techniques allow these images to be aligned and co-registered, with simultaneous visualization of these structures. This report describes the anatomical and functional characteristics of apical aneurysms in chronic Chagas’ heart disease patients using different modalities of three-dimensional cardiac image co-registration, most specifically, myocardial perfusion and labeled blood pool images.

Caracterização de lesões intersticiais de pulmão em radiograma de tórax utilizando análise local de textura

OBJECTIVE: To characterize interstitial lesions in anterior-posterior chest X-rays based on the analysis of textural statistical features that allow the detection of abnormalities with diffuse pattern. MATERIALS AND METHODS: Image analysis begins with the semiautomatic segmentation of the lungs, marking the external contour of the lung manually followed by an automatic division of each lung in six regions. The data base of images used in this study consisted of 482 regions obtained from examinations in which lesions were detected and 324 regions from normal examinations. Textural features were automatically extracted from each area and the selection of the best set of features was made based on the Jeffries-Matusita distance. The regions were classified as normal or suspected using the k nearest-neighbor method and half-half, and cross-correlation methodologies were used for training the classifier. RESULTS: Results were assessed based on the value of the area under the ROC (receiver operating characteristic) curve that indicates an ideal response for an area equal to 1. The results showed an area under the ROC curve (AZ) of 0.887, sensitivity of 0.804, and specificity of 0.793. CONCLUSION: These results indicate that the implemented system has a good potential for computer-aided diagnosis of interstitial lung lesions.

Auxílio à detecção de anormalidade perfusional miocárdica utilizando atlas de SPECT e registro de imagens: resultados preliminares

OBJECTIVE: To develop an atlas of myocardial perfusion scintigraphy and evaluating its applicability in computer-aided detection of myocardial perfusion defects in patients with ischemic heart disease. MATERIALS AND METHODS: The atlas was created with rest-stress myocardial perfusion scintigraphic images of 20 patients of both genders with low probability of coronary artery disease and considered as normal by two experienced observers. Techniques of image registration and mathematical operations on images were utilized for obtaining template images depicting mean myocardial uptake and standard deviation for each gender and physiological condition. RESULTS: Myocardial perfusion scintigraphy images of one male and one female patient were aligned with the corresponding atlas template image, and voxels with myocardial uptake rates two standard deviations below the mean voxel value of the respective region in the atlas template image were highlighted on the tomographic sections and confirmed as perfusion defects by both observers. CONCLUSION: The present study demonstrated the creation of an atlas of myocardial perfusion scintigraphy with promising results of this tool as an aid in the detection of myocardial perfusion defects. However, further prospective validation with a more representative sample is recommended.

Coregistration of brain single-positron emission computed tomography and magnetic resonance images using anatomical features.

The present report describes a computer tool for the coregistration of single-positron emission computed tomography (SPECT) and magnetic resonance (MR) images to aid the diagnosis. Two types of images are used for some neurologic diseases: one of them anatomic (magnetic resonance) and the other metabolic (SPECT), with the specialist being required to make a mental integration of the examinations. This procedure can be improved by using a computer tool that might permit the presentation of this information in a single image. The coregistration is performed on the basis of pairs of points positioned by a specialist according to the structures present in the images and the least squares error is calculated between them using Euclidean distance. Coinciding planes and section thickness are selected for the two modalities and the SPECT image is processed so as to have the same spatial resolution as the resonance image.

Software architecture and reference architecture of software-intensive systems and systems-of-systems: contributions to the state of the art

Complex software-intensive systems are more and more required as a solution for diverse critical application domains; at the same time, software architecture and also reference architecture have attracted attention as means to more adequately produce and evolve such systems. The main goal of this paper is to summarize our principal contributions in software architecture and reference architecture of software-intensive systems, including Systems-of-Systems. We intend this work can also inspire the opening of other related research lines towards founding the sustainability of such software-intensive systems.

Epistaxis during a generalized seizure leading to an atypical ictal SPECT finding at the skull base

INTRODUCTION: Generalized tonic-clonic seizures (GTCS) are among the most dramatic types of epileptic seizures and may be accompanied by rising blood pressure and pulse rate, physical injuries from falling, muscular convulsions, tongue biting, or aspiration pneumonia. Epistaxis is an uncommon complication of generalized seizures and investigations should exclude local or systemic disorders. OBJECTIVE: We aim to report a 29-year-old male patient with medically intractable right temporal lobe epilepsy whose ictal SPECT showed a conspicuous high extracerebral accumulation of the tracer at the skull base. METHODS: The tracer 99mTc-ECD was injected during a GTCS complicated by simultaneous epistaxis during a long term video-electroencephalographic monitoring. RESULTS: Initially, SPECT images showed an unexpected hot spot at the skull base suggesting pharyngeal or pituitary tumors. Clinical history disclosed chronic sinusitis and rare episodes of epistaxis. White and red cells blood count, platelet count, serum biochemistry, coagulation tests, and rest arterial blood pressure were normal. Computed tomography and MRI excluded sinusoidal expansive or vascular lesions, head trauma, fractures or acute infections. Subtracted SPECT disclosed a focal high concentration of the radiotracer within the left sphenoid sinus, probably related to the nose bleeding. CONCLUSION: This is a singular case of a brain SPECT artifact secondary to a nasal bleeding during a generalized seizure that was misinterpreted as neoplastic disease. Also, this case raises concerns about the pathophysiological relationship among epileptic seizures, nasal bleedings and chronic sinusitis.

Identificação de amostras de sementes utilizando VisãoComputacional

Diversos sistemas computacionais voltados ao Agronegocio foram desenvolvidos visando melhorar a produtividade, qualidade dos produtos, reduzir desperdicios e auxiliar na tomada de decisoes. Da mesma forma, medidores de umidade estao cada vez mais tecnologicos e, neste caso, automatizacao do processo de medicao auxilia na reducao de erros e aumento de produtividade. Neste contexto, o presente trabalho apresenta uma metodologia para obtencao de imagens de sementes e classificacao utilizando metodos de Visao Computacional. Uma base de imagens com treze tipos de sementes foi criada para avaliacao do metodo de identificacao proposto. Quatro descritores foram extraidos, avaliados individualmente e de forma combinada, sendo utilizados como entrada no classificador SVM. O metodo proposto obteve uma taxa de acerto superior a 85% em 12 dos 13 tipos testados, mostrando a viabilidade da sua utilizacao na identificacao de sementes, para uma posterior analise de umidade.