The iron reabsorption index: a new phenotypic and pathophysiological descriptor in HFE hemochromatosis.

BACKGROUND: The current phenotypic descriptors of high Fe gene hemochromatosis are hardly specific and time dependent in a context of highly variable expressivity. We hypothesized that the rate of iron removed during maintenance therapy and corresponding to the iron reabsorption index (IRI) could be patient specific and may then represent a new useful phenotypic marker. AIM: The present study aimed to describe IRI with respect to its phenotypic specificity and to its potential usefulness. METHODS: We studied a cohort of 316 p.Cys282Tyr homozygous patients with stable low serum ferritin levels on maintenance therapy for at least 12 months. Characteristics at diagnosis, date and volume of phlebotomies, and parameters of iron metabolism throughout maintenance therapy were determined. RESULTS: IRI ranged from 1.3 to 6.1 mg/day (median: 2.44). It was lower in women (difference: 1.26 mg/day), mainly explained by physiological blood loss, weight, and alcohol consumption. IRI was correlated to iron burden and fibrosis stage at diagnosis, was stable over time (variation: 11.5%), and depended on serum ferritin level during therapy. CONCLUSION: Its independence from disease duration, its stability, its wide distribution, and its significant correlation with iron burden markers make IRI a valuable potential phenotypic indicator of the daily iron overabsorption in hemochromatosis. Moreover, IRI provides a conceptual frame for empiric adaptation of maintenance therapy.

An ECG analysis interactive training system for understanding arrhythmias.

The ECG remains a daily diagnostic tool for the detection of numerous cardiovascular diseases. Our goal was to use a computerized qualitative model (QM) of heart in order to build cases of simple arrhythmias dedicated to initial and more advanced medical teaching. The original QM is able to generate videograms of many cardiac disturbances. A Flash player is used to view ECG, synchronous Lewis diagram and chromatic 2D cardiac animation of a specific case. OAAT is a standardized 18 yes/no answers questionnaire which allows the learner to diagnose five main types of arrhythmias that can be compared with normal sinus rhythm (NSR) analysis. This new tool has been recently used by medical students during practical sessions. Based on medical reasoning learning on NSR video and upon trying to recognize an abnormal cardiac rhythm, all users can reach the 100% winning score since they can perform as many attempts as they like. We believe that unlimited case review with questionnaire answering, ECG and Lewis diagram replay and step-by-step visualization of the abnormal propagation of the cardiac impulse on the 2D heart videos are a highly efficient means to help students understand even complex arrhythmic mechanisms.

Multimedia and physiology: a new way to ensure the quality of medical education and medical knowledge.

BACKGROUND: since the eighties and the existence of virtual campuses, the value of computers in distance education has been acknowledged. The development of information and communication technologies is driving at discriminating distance education and on-line education. PURPOSE: the aim of the "Campus Numérique de Physiologie" is not to reproduce an on-line copy of classical textbooks but to put at students' and physicians' disposal the huge possibilities of multimedia resources for an active and easier understanding of complex physiopathological phenomena. METHODS: the on-line course materials were created using both original IBC-made and registered trade-mark software tools. Multiscale modelling and corresponding knowledge bases were implemented by mathematicians, biologists and software engineers from Rennes. The website, which is accessible through a server of the French Virtual Medical University, was developed in the language HTML/PHP connected to a MySQL database. RESULTS: the content managing system is consistent with classical home page facilities and multicriteria browser. Interactive resources are freely available for the site's users. Two- and three-dimensional simulations born out of mathematical qualitative and quantitative models at the molecular, cellular or organic level keep students active with regards to fundamental mechanisms by interactively manipulating the simulation environment. CONCLUSION: authors comment the already available course materials which should stimulate the creation of new documents following a validation by a qualified commission of the "Société de Physiologie". Providing evaluation tests, teachers anticipate that the increasing content of this virtual campus will allow users to gain a complete understanding and an integrative view of many physiopathological mechanisms.