[Medical informatics].
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Medical Informatics↗
Biomedical subjects
M I Leão
Publications and source records attributed to M I Leão.
Comparisons of models of cortical necrosis with segmental infarction.
Sodium and water excretion were studied by standard clearance techniques in three experimental models where renal mass was reduced by superficial cortical necrosis (CN) or ischemic segmental infarction (SI). During hydropenia either CN or SI were able to conserve and regulate sodium to a very similar degree. After expansion of extracellular volume, CN reabsorbed less sodium and water than SI. In free-water clearance (CH2O) experiments, the 'apparent distal' sodium delivery was higher in CN than in SI, suggesting a decreased sodium and water reabsorption in the proximal tubules of juxtamedullary nephrons (JM). Both kidneys had similar CH2O when factored for inulin clearance but when CH2O was corrected for 'apparent distal' sodium delivery it was lower in CN than in SI, demonstrating an incapacity of JM to dilute urine. CN also showed less capacity to reabsorb free water than SI. Thus, the use of CN and SI within the same animal was useful to study functional differences between superficial and juxtamedullary nephrons. The present study also suggests that the kidney with superficial CN was unable to perform maximal urine dilution and concentration.
Absorption↗
[Safety rules for patients with artificial cardiac pacemaker].
The recent progress in cardiac pacing increased the usefulness of artificial pacemakers. The initial purpose of avoiding Stokes-Adams attacks, was changed by a complex way to completely give back the physiologic response of cardiac rate and atrioventricular synchronism. However, this process forced the patients to take care of their pacemakers, and to spend more time in follow-up procedures. Additionally, the pacemakers became more vulnerable to environmental and hospital interferences. Basic rules, for all patients, are described in this paper, in order to improve their quality of life. Follow-up procedures are related in detail. It is described how programmed electronic evaluations can contribute to avoid complications, to detect subclinic problems and to improve the patient's haemodynamics and physical capacity. It shows also how to use complementary examinations, like thoracic X-rays, exercise testing and Holter monitoring to optimize the cardiac pacing system. Interferences in pacemakers are focused with special attention to myo-potentials, environmental electromagnetic fields, and damage to system owing to medical procedures, like therapeutic radiation, defibrillation and electrocauterization. The approach to infective processes in pacemakers gives special emphasis to prevention of direct surgical contamination, erosion of the skin, and haematogenic dissemination of distant infective focus.
Cardiac Pacing, Artificial↗