Stem cells and their physiological effects

Abstract

The characteristic of various populations stem cells is presented. Their physiological features are examined: differentiations, dedifferentiation, transdifferentiation, plasticity, and also the factors promoting their display. The comparative characteristic embryonic and somatic stem cells which are closest to practical application is received broad covarage. It is shown, that embryonic stem cells are differentiated in three various types of tissue: endoderm, giving rise to internal bodies, mesoderm from which develops connecting, muscular and bone tissue, and also the system of blood circulation and ectoderm, a derivative of a skin, sense organs and nervous cells is formed. Because of ability to be differentiated in various types of tissue embryonic stem cells name multipotenteus. Somatic stem cells also are capable to the differentiation however more limited, than embryonic. Somatic cells of one type are capable to give rise to other types of cells. This property makes possible application somatic stem cells for therapy and reparation of the sick and damaged tissues. Use somatic stem cells limits that they give in to differentiation more difficultly and are cultivated in laboratory conditions worse, than embryonic. It is confirmed, that one of the most strongly pronounced attributes of ability of a cell to prolonged proliferative activity is the size cellular telomere, directly connected with activity of enzyme telomerase. The more actively telomerase and is longer telomere, the to longer proliferative activity and to longer self-maintenance the given cell is capable. Advantages, lacks and prospects of various methods of allocation and enrichment hemopoietic stem cells from peripheral blood, a bone brain and umbilical blood of the newborns, being by the most perspective source of reception hemopoietic stem cells are examined and characterized.