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Mathematical modeling in biomedical sciences is particularly difficult because of the great amount of variables that the biological phenomena imply, the difficulty in observation and experimentation, and the scarceness of mathematical methods suitable for incorporating all of these variables. Even so, many mathematical models can be found in biology which include reduccionist, structural or integrative approaches. Theoretical models in biology are designed upon clearly defined purposes and may extent from the molecular level to the intact organism. For a model to be useful, its variables, levels and links must be very explicit. Observable and measurable aspects of the heart allow a modeling approach of this organ, in normal or in pathological conditions. A few examples are mentioned. Mathematical modeling of the heart may help orient experimental research, join existing data and theories and it may also be of assistance as therapeutic guidance.

The sense of psychopathology is interpreted as the development of a descriptive language, that allowed the approach to the psychiatric disease in the context of natural sciences. The phenomenology was introduced as a methodological tool for the improvement of this language. Since then this topic has been present in the foundations problems of psychiatry. In this paper the discussion is set towards the influence of phenomenology in psychopathology, as a controversy between two opposite points of view. The authors establish their own arguments about the limits of psychopathological knowledge and psychiatric experience.

The aim of the present paper was to study the effects of adenosine (ADO) on automaticity and after potential oscillations on canine cardiac Purkinje fibers. ADO concentrations from 10(-8) to 10(-5) M were used. The intracellular electrical activity was recorded with conventional microelectrodes. ADO increased during the first two minutes the basic cycle length (BLC) with concentrations higher than 10(-8) M, to a value 50% above control, later there is a progression to a steady state. The dose-response curve in the steady state is sigmoidal and resembles those of receptor occupation. The slopes of pacemaker potentials have a tendency to decrease along with the increase in BLC length. After potential oscillations decrease with 10(-8) M of ADO but not with larger concentrations. There results supports the hypothesis that ADO produces an increase in the time independent potassium current similar to the one described for atrial and ventricular myocytes. This effect probably depends on specific receptor stimulation. The biphasic time course suggests the existence of subtypes of A1 receptor with different dissociation constants and affinities but with similar actions. The idea that the ADO effects depend mainly on the potassium currents and not on I(f) is supported by the absence of a dose-dependent effects in the oscillatory after potentials.

Glucose facilitated diffusion into cells depends on concentration gradients between intracellular and extracellular spaces and can be modified by several factors such as insulin and contractions. Calmodulin participates in the insulin induced recruitment of vesicles containing glucose transporter molecules and its inhibition by trifluoperazine blocks insulin increases in glucose uptake. In the present study we tested if calmodulin inhibition with trifluoperazine blocks hindlimb muscle glucose uptake increase induced by contractions. Trifluoperazine does not inhibit exercise induced increases in glucose uptake; therefore, the mechanisms by which insulin and functional activity increase glucose uptake are different.

As much as it strives to be "scientific" psychiatry can not obviate its necessary bonds to the subjectivity of the subject. The attempt has been made to reflect the richness of manifestation of subjectivity by means of a formalization process based on the traditional concept of it. This has led to the concept of disorders of self (Ichstörungen). They are of central importance in clinical psychiatry and psychopathology, as can be seen in the attempts to conceptualize schizophrenia. However, the presumed degree of precisión reached runs parallel to the apartness of the fidelity to the effective vivification of the patient. This discord is interpreted as a fault in the conceptualization of the disorders of self and the possibilities originates by corporality point to the need to redefine, once again and in depth, the concept of subjectivity which is the foundation of psychiatry.

This paper is a revision of the present situation of child psychiatry showing its confluence with general psychiatry through the epistemological unification as a biopsycho-social model. The psychopathological limitations of this process as empiricism are taken into account as well as its identity, which did not really exist till now. At the same time this identity supposes an orientation for the clinical, teaching and research action.

A groupe of 52 patients in long-term lithium treatment were questioned about side effects. The K. Ghose questionnaire was used which contained 36 items. The most frequent complaints were hand-tremor, dry mouth, poor memory, polyuria, diarrhoea, weight gain. We hypothesize that apart from symptoms clearly demonstrated to be caused by lithium treatment (polyuria, hand-tremor, weight gain diarrhoea). Other complaints such as dry mouth, poor memory or skin eruptions occur frequently and they are also related to lithium.

This work pretends to show the necessity of psychiatry of knowing its grounds as medical knowledge in order to do justice to its history and to the concepts that have been traditionally used in the west way of thinking. By the idea of experience it is tried to search in psychopathology the motives of the transformation of psychiatry under the operative concept of 'life world'. The psychiatry tasks shall be those in connection with the development and appropriation of the ontological and methodological implications that the concept of 'life world' involves, always across a psychopathological theory.

Two hundred and twenty four electrophysiologic studies were performed in 194 patients during a two-year period. One hundred and six (54.6%) had tachyarrhythmias: 21 had atrial tachycardia, 28 had the Wolff-Parkinson-White syndrome. Of 51 patients with a normal electrocardiogram a concealed left Kent bundle was observed in 21 cases and only one concealed right Kent bundle; functional James fibers were seen in 7 patients and Mahaim fibers in two. In 15 patients A-V nodal reentry was diagnosed and functional ectopy was observed in 5 patients. The sick-sinus-syndrome was seen in 24 patients and atrial arrest in three. Thirty patients underwent a second electrophysiologic study to evaluate proper antiarrhythmic therapy. Atrioventricular conduction was evaluated in 52 patients. A "suprahisian" delay was found in 34%, troncular lesions were diagnosed in 31%, a distal delay in 25% and mixed conduction disturbances in 10%. We conclude that electrophysiologic studies are a useful procedure to: 1) establish the etiologic diagnosis of tachyarrhythmias; 2) evaluate their potential danger; 3) objectively evaluate antiarrythmic therapy; 4) establish the need for surgical treatment; 5) give the topographic diagnosis and severity of A-V conduction disturbances and 6) indicate the need for definitive pacemaker implant.