Knowledge Discovery in Spectral Data by Means of Complex Networks

In the last decade, complex networks have widely been applied to the study of many natural and man-made systems, and to the extraction of meaningful information from the interaction structures created by genes and proteins. Nevertheless, less attention has been devoted to metabonomics, due to the lack of a natural network representation of spectral data. Here we define a technique for reconstructing networks from spectral data sets, where nodes represent spectral bins, and pairs of them are connected when their intensities follow a pattern associated with a disease. The structural analysis of the resulting network can then be used to feed standard data-mining algorithms, for instance for the classification of new (unlabeled) subjects. Furthermore, we show how the structure of the network is resilient to the presence of external additive noise, and how it can be used to extract relevant knowledge about the development of the disease

Axillobifemoral bypass for total abdominal occlusion secondary to Takayasu's arteritis:A case report

INTRODUCTION: Takayasu's arteritis (TA) is a rare disease that mainly affects large arteries. Approximately 20% of TA patients will require surgical intervention secondary to arterial complications such as intermittent claudication, persistent hypertension refractory to treatment, and heart failure. PRESENTATION OF CASE: The case of a 22-year-old female with TA of five years of evolution is presented. The patient deteriorated clinically after five years of corticosteroid and immunosuppressant management requiring surgical intervention with an axillobifemoral bypass for a total abdominal occlusion. Onset, pre-surgical and post-surgical Doppler ultrasonography as well as abdominal angiotomographies document and corroborate the patient's clinical and hemodynamic improvement. DISCUSSION: Very limited literature exists regarding surgical interventions for TA patients. While most reported cases present an endovascular surgical management. Open surgical procedures have lower rates of restenosis than endovascular management. Although endovascular management is less invasive than extra-anatomical axillobifemoral bypass, the patient was not a candidate for endovascular stent graft placement due to the increased risk for vascular injury and subsequent perforation. Approximately a fifth of TA patients are candidates for surgical intervention over time. CONCLUSION: Vascular surgery in TA cases becomes an option when the patient does not improve clinically after administration of medical treatment. Although endovascular management has fewer complications, the rate of restenosis is higher. Patients at risk of restenosis and who have increased perioperative vascular risk can benefit from open surgical procedures. Surgical management should be tailored to the patient's needs

Caracterización eléctrica de tejido sanguíneo mediante función de transferencia Caracterización eléctrica de tejido sanguíneo mediante función de transferencia

This paper presents an analysis and modeling of electrical impedance spectra applied to the study of experimental data of blood tissue and its main components: red cells, white and plasma. Using the electrical circuit theory yields the transfer functions and the graphic representation of Bode and Nyquist. You can see in this work the experimental technique’s potential to differentiate cellular components of blood tissue, and the usefulness of developing accurate models for analysis. En este trabajo se presenta un análisis y modelado de espectros de impedancia eléctrica aplicados al estudio de datos experimentales de tejido sanguíneo y sus principales componentes: glóbulos rojos, blancos y plasma. Usando la teoría de circuitos eléctricos se obtienen las funciones de transferencia y la representación gráfica de Bode y Nyquist. Se puede ver en este trabajo el potencial de la técnica experimental para diferenciar los elementos que forman al tejido sanguíneo, así como la utilidad de desarrollar modelos precisos para su análisis. </span