[Stem cell perspectives in myocardial infarctions].

Myocardial infarction is the leading cause of congestive heart failure and death in industrializated countries. The cellular cardiomyoplasty has emerged as an alternative treatment in the regeneration of infarted myocardial tissue. In animals' models, different cellular lines such as cardiomyocites, skeletal myoblasts, embryonic stem cells and adult mesenchymal stem cells have been used, resulting in an improvement in ventricular function and decrease in amount of infarcted tissue.

Direct cardiac injection of G-CSF mobilized bone-marrow stem-cells improves ventricular function in old myocardial infarction.

Autologous transplant of bone marrow stem cells (BMSC), although extremely useful after acute myocardial events, has not been evaluated in patients with old (>one-year-old) myocardial infarction. Our aim was to determine if CD34(+)-enriched peripheral-blood cells, obtained by apheresis, injected directly into the severely damaged myocardium of five patients with old myocardial infarction could restore depressed myocardial function. We found that 28 weeks after revascularization and peri-infarction injection of the enriched CD34(+) peripheral mononuclear cells, ventricular hemodynamic parameters that included left ventricular ejection fraction, left ventricular diastolic volume, ventricular systolic volume and left ventricular diastolic diameter approximated normal values and there was no restenosis; two patients have been followed for >52 weeks and their parameters are within normal values.

A subpopulation of large granular von Willebrand Ag negative and CD105 positive endothelial cells, isolated from abdominal aortic aneurysms, overexpress ICAM-1 and Fas antigen.

The aim of this work was to determine whether there is a pre-established basal condition of the endothelial cells isolated from aortic abdominal aneurysm that might augment immune effector mechanisms and thus provide us an insight into the possible causes of aneurysm rupture. Endothelial cells isolated from saccular aortic aneurysm fragments were analyzed by cytofluorometry for the expression of different immune response-related molecules. Our results showed that there is a subpopulation of granule-rich, CD105 positive and von Willebrand antigen negative endothelial cells that have an enhanced basal expression of ICAM-1, and Fas antigen, but, interestingly, no apoptotic bodies were detected.