Computational simulation of chronic persistent virus infection: factors determining differences in clinical outcome of HHV-6, HIV-1 and HTLV-1 infections including aplastic, hyperplastic and neoplastic responses.

A computational model was recently designed to simulate cellular changes in the T cell immune system. The model was validated by simulating cell changes in viral infections which target the same CD4+ T cell, yet cause either hyperplastic, aplastic or neoplastic responses. Respective case material for comparison was available from human infections with human herpesvirus-6 (HHV-6), human immunodeficiency virus (HIV-1) or human T cell leukemia virus (HTLV-1). Starting with cell values for a healthy human individual, factorial changes that influence the individual course of the various infections were determined by an algorithm search procedure. Such factorial differences determining a clinical course with aplasia, hyperplasia or neoplasia are outlined and further discussed in this paper.

Generation of classification criteria for chronic fatigue syndrome using an artificial neural network and traditional criteria set.

OBJECTIVE: The definition of chronic fatigue syndrome (CFS) is still disputed and no validated classification criteria have been published. Artificial neural networks (ANN) are computer-based models that can help to evaluate complex correlations. We examined the utility of ANN and other conventional methods in generating classification criteria for CFS compared to other diseases with prominent fatigue, systemic lupus erythematosus (SLE) and fibromyalgia syndrome (FMA). PATIENTS AND METHODS: Ninety-nine case patients with CFS, 41 patients with SLE and 58 with FMA were recruited from a generalist outpatient population. Clinical symptoms were documented with help of a predefined questionnaire. The patients were randomly divided into two groups. One group (n = 158) served to derive classification criteria sets by two-fold cross-validation, using a) unweighted application of criteria, b) regression coefficients, c) regression tree analysis, and d) artificial neural networks in parallel. These criteria were validated with the second group (n = 40). RESULTS: Classification criteria developed by ANN were found to have a sensitivity of 95% and a specificity of 85%. ANN achieved a higher accuracy than any of the other methods. CONCLUSION: We present validated criteria for the classification of CFS versus SLE and FMA, comparing different classification approaches. The most accurate criteria were derived with the help of ANN. We therefore recommend the use of ANN for the classification of syndromes with complex interrelated symptoms like CFS.

Immunopathology of liver diseases

Esta revisión resume los conocimientos actuales de la copatogénesis inmunopatológica de las principales enfermedades hepáticas, incluyendo la hepatitis viral, hepatitis autoinmune, rechazo de trasplante, reacción del huésped hacia el injerto y otras. El trabajo se refiere principalmente a las implicaciones de los datos para el diagnóstico de la práctica clínica y en menor grado a los datos de las más recientes investigaciones, por lo que está dirigido principalmente al hepatólogo y al patólogo en ejercicio. Los autores desean que la lectura de este trabajo sirva como referencia práctica para el diagnóstico diferencial de las enfermedades hepáticas cada vez más frecuentes

Carcinoma nasofaringeo: actualizacion del tema y frecuencia en nuestro medio / Nasopharingeal carcinoma: update and prevalence in Colombia

El carcinoma Nasofaringeo (CNF) es una neoplasia que se origina en el epitelio que recubre las criptas de la nasofaringe. En el momento actual constituye un modelo unico para investigar la contribucion de factores geneticos, virales y quimicos en la etiologia de un tumor maligno en el hombre. Se sabe que el virus de Epstein Barr, esta implicado en su etiologia pero el mecanismo de su accion no se conoce. En el presente articulo se actualiza la informacion mas reciente relacionada con la neoplasia y se presentan los resultados de un estudio que sobre la frecuencia relativa y la biologia del CNF se ha efectuado en nuestro medio