Analysis of the position of the left ventricular apex and base during systole.

The relative positions of the left ventricular apex and base in end-diastole (ED) and end-systole (ES) were determined in a group of normal individuals using cross-sectional echocardiography (group A) and in a group of patients with normal hemodynamics and angiographic parameters using cine-computed tomography (group B). In both groups no change was detected in the position of the epicardial aspect of the apex from ED to ES. The base moved in direction of the apex by 10.2% +/- 1.9% (mean +/- standard deviation) of the longitudinal dimension of the chamber in group A and by 12.9% +/- 5.1% in group B. In both groups the apical cavity was obliterated by the peri-apical walls. Apical obliteration is responsible for the apparent movement of the apical segment seen in cineventriculography.

Infeccao experimental de macacos Cebus apella sp pelo Trypanosoma cruzi.II - Reisolamento de cepas e estudo de suas caracteristicas em camundongos albinos. / Experimental infection of monkeys Cebus apella sp by Trypanosoma cruzi. II - Re-isolation of strains and study of their characteristics in albino mice

De macacos Cebus apella sp. na fase cronica da doenca de Chagas, foram reisoladas as cepas Y, Yr, 200 e 339 por intermedio de xenodiagnostico (Triatoma infestans) e a cepa 245 tambem por inoculo direto de sangue do macaco em camundongos (formas tripomastigotas). Apos o reisolamento, as referidas cepas foram inoculados em camundongos albinos machos (Swiss), e tiveram novamente estudadas suas caracteristicas biologicas. Os Autores concluem que as cepas mantiveram suas caracteristicas, ja anteriormente conhecidas, e discutem ainda o conceito de virulencia de cepa durante sua manutencao em laboratorio atraves de sucessivas passagens por camundongos, sugerindo o macaco Cebus apella sp como um hospedeiro para a manutencao de cepas in vivo, por longo periodo, sem que as mesmas aumentem sua virulencia

Sequence of shortening of the normal human left ventricle.

Left ventricular sequence of shortening was studied through the analysis of cineventriculograms in 30 degree right anterior oblique projection of 11 normal patients. In all patients transverse shortening progressed in base to apex direction, in a concentric fashion. Base descent started simultaneously with the first transverse inward motion and continued throughout systole. There was a slight protrusion of the apex in the beginning of systole, lasting a mean of 115 ms.