[Catheter ablation of accessory pathways with low energy. Results in 40 consecutive patients]. / Ablação por cateter de vias acessórias com choques de baixa energia. Resultados em 40 pacientes consecutivos.

PURPOSE: To evaluate the results of direct current catheter ablation of accessory pathways by mean of a new low energy power source. METHODS: Catheter ablation was performed in 40 consecutive patients (23 male, mean age 31 +/- 11 years) with accessory atrioventricular pathways (AP) using a low energy DC power source. The electrophysiologic study and AP ablation were performed in the same procedure by endocardial approach using non-deflectable 6F bi, tri, or quadripolar electrodes. RESULTS: AP was located at left free wall (LFW) in 22 patients (55%), posteroseptal (PS) in 11 patients (27.5%), anteroseptal (AS) in 5 patients (12.5%) and right lateral (RL) in 2 patients (5.0%). A mean of 7.7 +/- 7 catodal shocks of 5-75 (20) joules (J) was delivered in 1.45 +/- 7 sessions, with a mean cumulative energy of 178 +/- 213J per patient. The mean values of number of shocks, number of sessions and cumulative energy per patient were lower in LFW AP ablation than in other positions (5 +/- 4 x 11 +/- 8 - p = 0.008; 1.1 +/- 0.3 x 1.8 +/- 0.9 - p = 0.008 and 118 +/- 150 x 260 +/- 245 - p = 0.03). The mean CK-MB rise was 18.5 +/- 7.8U/1. Three patients (7.5%) presented hemopericardium after PS AP ablation and in 1 patient (2.5%), a PS AP (paranodal pathway) ablation resulted in total atrioventricular block. During a follow-up of 9.5 +/- 4 months AP was absent in 28 (70%) patients; 18/22 (82%) with LFW AP, 6/11 (54%) with PS AP, 3/5 (60%) with AS AP and 1/2 (50%) with RL-AP, (p = 0.10). CONCLUSION: Low energy DC ablation is effective for AP ablation. The results are related with AP position.

Lesoes ultra-estruturais do cerebro de camundongos albinos inoculados experimentalmente com o virus Piry (BeAn 24232). / Brain ultraestructural lesions of albino mice experimentally inoculated with Piry virus (BeAn 24232)

A inoculacao experimental do virus Piry (Be An 24232) em camundongos albinos recem-nascidos induz a formacao de uma encefalite com lesoes graves, de celulas isoladas ou focais, que evoluem para necrose e na qual a reacao inflamatoria e discreta e so aparece na fase final da evolucao. A modificacao mais precoce e a diminuicao da eletrondensidade e a marginacao da cromatina nuclear. Seguem-se modificacoes de organelas, mais intensas nas mitocondrias e no Golgi, com reagrupamento delas.Os citolisosomas surgem no citoplasma celular e, em maior quantidade nas celulas produtoras de virions. Os GERL sao muito proeminentes e guardam relacao direta com a presenca de maior numero de particulas. O virion e montado na membrana citoplasmatica de neuronios e acumulado no intersticio, com raras vesiculas virus-similes no citoplasma, vizinhas as areas de sintese virotica