Autori: Viorel Pais, Leon Danaila
Editorial: Proceedings of the American Association of Neurological Surgeons, 2010.
Introduction. This study is to understand the nature and functional significance of the activated cell death programs during events of the postnatal vasculogenesis and late changes after neurotrauma. Methods. We used light and transmission electron microscopy to describe changes of the cells in vasculogenic focuses and dying cells in the damaged arteries. Results. Vasculogenic focuses were composed of a nondifferentiated cell population including few cells with apoptotic and paraptotic features, approximately in equal percentage. Within tunica media of the posttraumatic arteries, four months after the craniocerebral injury, apoptotic and paraptotic phenotypes were identified, with an increased number of paraptotic cells. Ultrastructurally, most of these dying cells showed typical features of apoptosis (shrinking cell body and nucleus, compact and condensed cytoplasm with intact organelles) or paraptosis (enlarged cell body, vacuolised cytoplasm, with or without chromatin condensation, dilated endoplasmic reticulum). Conclusion. The two groups of suicidal cells – apoptotic and paraptotic cells – were encountered during two different situations: (1) early, in the mass of proliferating vascular cells, and (2) late, within tunica media after neurotrauma. The pathophysiologic significance of the coexisting cell death programs seems to be in relation with the early events that occur in the blood clot when it is necessary to reduce exceedingly proliferated cells, for normal vessel development, and in relation with the late cell survival, after arterial injury.
Cuvinte cheie: Apoptosis, paraptosis, electron microscopy