Stem cells (stem cell) "dry", which translated from the English "stem", meaning "trunk." In other words, like a tree trunk stem cells, with the trunk can grow tree branches, leaves, and flower and bear fruit. Stem cells have two important characteristics: First, there is a high degree of self-renewal or self the second is the ability to differentiate into various types of mature cells. The so-called self-renewal is defined by a stem cell divides into two cells. One of the cells remain stem cells in all biological characteristics, so as to maintain the number of stem cells in the body is relatively the other cells then further proliferation and differentiation of precursor cells and mature cells.
According to different criteria, divided into many types of stem cells. For example, according to the developmental potential of stem cells into pluripotent stem cells, pluripotent stem cells, single stem cells three categories. Totipotent stem cell is the ability to develop into a complete individual cells have the potential of a variety of tissues and organs, such as the fertilized egg. Pluripotent stem cells differentiate into a variety of cells and tissues of potential, but do not have the ability to develop into a complete individual, developmental potential subject to certain restrictions, such as embryonic stem cells. Single stem cells refer only to a single differentiation, resulting in one or more closely related to the types of cells, such as hematopoietic stem cells, neural stem cells, cardiac stem cells.
According to the developmental stage in which the stem cells, stem cells and embryonic stem cells can be divided into two major categories of stem cells. Embryonic stem cells from the inner cell mass of blastocysts, is a highly undifferentiated cells, with the development of totipotent, capable of differentiating into all the tissues and organs of the animal body. Adult stem cells are fetal, child and adult tissues present in pluripotent stem cells collectively. Compared with embryonic stem cells, adult stem cells wide, relatively easy to from a patient's own adult stem cells in tissue compatibility issues do not exist in the application, you can use to avoid transplant rejection and immune suppression. At the same time, adult stem cells tumorigenic risk is very low, less controversial ethics suffered, so it has broad application prospects.
Stem cells are currently more popular, there are two. First, induced pluripotent stem cells (iPS cells), which refers to the gene transfection techniques by certain transcription factors introduced into the animal or human somatic cells, somatic cells directly reconstructed into embryonic stem cell-like cells pluripotent cells. Second, mesenchymal stem cells (MSCs cells), it exists in the adult body in many tissues, such as bone, cartilage, fat, skin, muscle, nerve, pancreas, etc., with multiple differentiation potential, have low immunogenicity and the lack of blood or tissue damage homing feature, organ repair in regenerative medicine is the ideal seed cells.
Stem cell research since the 1990s in the field of medicine and biology the most striking one of the hotspots. In 1999, the American magazine "Science" will stem cell research as the most important research areas of the first 10 in the 21st Century. Currently, stem cells and regenerative medicine research has become the most striking natural sciences areas and improving the rapid development of the theory of art will have a landmark achievement in the field of bio-medicine and disease treatment, it is the traditional medical means and the concept of a major revolution in healthcare.
In theory, stem cells can be used for clinical cell transplantation in the treatment of various diseases and to build artificial tissues or organs, which are suitable diseases include: tissue diseases such as myocardial necrosis caused by ischemia and necrosis, degenerative diseases such as Parkinson's syndrome, autoimmune diseases such as rheumatoid arthritis, diabetes, bone and joint diseases. However, most of these studies are still in clinical trials, the distance became the standard drugs for the treatment of clinical disease is still some way. It has now become a routine operation, only hematopoietic stem cell transplantation in the treatment of blood diseases.
(Author: Zhao Chinese Academy of Medical Sciences researcher)
Baidu know without a daily newspaper written permission, any units and individuals shall not in any way or reason to know that Baidu content published daily use, copy, modify, copied, transmitted, or bundled with other products use, sale. Where the infringement of intellectual property Baidu know daily, it will pursue its legal responsibility according to the law. Application for authorization and commercial cooperation please contact zhidaoribao@baidu.com
Article Source: Baidu know daily (http://zhidao.baidu.com/daily)
Original link: http: //zhidao.baidu.com/daily/view id = 3685?