Stem cells undifferentiation

Stem cell. Undifferentiated, primitive cells in the bone marrow that have the ability to both multiply and to differentiate into specific blood cells. 

Stem Cell Undifferentiated cell type that gives rise to specialized cells within the body most are derived from embryonic tissues. 

There are undifferentiated stem cells of the blood elements in the bone marrow that differentiate and mature into erythrocytes, (red blood cells), thrombocytes (platelets), and white blood cells (leukocytes and lymphocytes). The production of erythrocytes is regulated by a hormone, erythropoietin (see the section on kidney toxicity), that is synthetized and excreted by the kidney. An increase in the number of premature erythrocytes is an indication of stimulation of erythropoiesis, i.e., increased production of erythrocytes in anemia due to continuous bleeding. 

Encapsulation of Stem Cells and Their Undifferentiated Character. 156... 

Xu C, Inokuma MS, Denham J, Golds K, Kundu P, Gold JD, Carpenter MK (2001) Feeder-free growth of undifferentiated human embryonic stem cells. Nat Biotechnol 19 971-974... 

The therapeutic application of stem cells has long been a dream of medical sciences, but recent discoveries and technical advances have brought this dream somewhat closer to being a reality. Stem cells are usually defined as undifferentiated cells capable of self-renewal that can differentiate into more than one specialized cell type. 

The main focus of stem cell research over the last few decades has been directed to embryonic stem cells. However, more recently, research upon and an understanding of various populations of adult stem cells has gathered pace. Adult stem cells are undifferentiated cells found amongst differentiated cells in a tissue or organ. These cells can renew themselves and can differentiate to yield the major cell types characteristic of the tissue in which they reside. The main physiological role of adult stem cells, therefore, appears to be to maintain and to repair (to a certain extent at least) the tissue in which they reside. 

The neural tube is a pseudostratified epithelium, with cells extending between the apical and basal surfaces of the epithelial wall. The neuroepithelium contains undifferentiated populations of stem cells and radial glia (see Ch. 29). With time, both of these cell types give rise to the three main lineages for neurons, astrocytes and oligodendrocytes. After the final mitotic division, neurons migrate away from the ventricular surface of the neural... 

Central nervous system stem cells maintain an undifferentiated state and the capacity to self-renew in response to epidermal growth factor and fibroblast growth factor 507 Cell lineage studies reveal close associations between distinct neural cell types 508... 

These cells are relatively undifferentiated and have a large nucleus, distinguishable nucleolus but few, if any, cytoplasmic granules. Myeloblasts arise from a precursor pool of stem cells, and both the rough endoplasmic reticulum and the Golgi apparatus stain for peroxidase, indicating that this enzyme is beginning to be synthesised. This cell type is capable of proliferation. 

In the EST, two murine cell lines are used to assess teratogenic potential the embryonic D3 stem cell (ES) which represents the embryonic tissue and the 3T3 fibroblast cell which represents the adult tissue. The D3 cells are maintained in an undifferentiated stage in the presence of leukemia inhibiting factor (LIE), then released from LIE and allowed to form embryo bodies that differentiate into cardiomyocytes. The D3 and 3T3 cells are exposed to a range of concentrations of the test ingredient. After a 10-day... 

Complete medium for culture of the undifferentiated ES-D3 embryonic stem cell line Dulbecco s Modified Eagle s Medium (DMEM), 20% Fetal bovine serum (FBS), 1% Nonessential Amino Acids (NEAA) (Gibco, Gaithersburg, MD), 2 mM L-Glutamine, 1% 5,000 lU/ml Penicillin/5,000 pg/ml Streptomycin, 0.1 mM P-Mercaptoethanol. 

After counting and calculating the cell number, the undifferentiated embryonic stem cell suspension is diluted in complete medium to 15x10 cells/ml. After the proper volume of the cell suspension is added to pre-warmed medium to achieve a concentration of 15 x 10 cells/ml, put the cell suspension on ice, to steadily lower the temperature within a few minutes. The cells can be kept on ice for 2 h. 

For continuing undifferentiated embryonic stem cell cultures, usually different cell densities are plated, and 2 days later select those cultures with optimal morphology and density for subculture. Cultures should not contain cells with differentiated morphology density should be around 70-80% with ample evidence of exponential growth as observed by cell division in culture. This procedure allows that some variation in culture... 

Hematopoiesis, the production from undifferentiated stem cells of circulating erythrocytes, platelets, and leukocytes, is a remarkable process that produces over 200 billion new blood cells per day in the normal person and even greater numbers of cells in people with conditions that cause loss or destruction of blood cells. The hematopoietic machinery resides primarily in the bone marrow in adults and requires a constant supply of three essential nutrients—iron, vitamin B12,... 

Stem cells are undifferentiated cells that have the ability to self-renew and differentiate into other cell types. Stem cells represent a promising model for cell-based therapy [8]. ESCs are self-renewing pluripotent cells derived from the inner cell mass (ICM) of the blastocyst. 

HLA expression and immunologic properties of differentiated and undifferentiated mesenchymal stem cells Le Blanc, K., Tammik, C., Rosendahl, K., Zetterberg, E., Ringden, 0. (2003). Exp Hematol, 31 (10) 890-896. 

The most convincing evidence for the importance of cytoplasm on nuclear development comes from studies on teratoma, a unique type of tumor found in many kinds of mammals. It is composed both of neoplastic cells, like other tumors, and of many kinds of differentiated cells. A typical teratoma may include nerve, muscle, blood, and skin cells, and other differentiated cells all mixed together with undifferentiated neoplastic stem cells. Only the stem cells are neoplastic, producing more stem cells or more differentiated cells, usually both. In many ways the stem cells behave like... 

The innermost layer of the epidermis, the stratum basale, consists of a single layer of columnar-shaped, undifferentiated stem cells. Mitosis of these cells constantly renews the epidermis and this proliferation compensates for the loss of dead stratum corneum cells (corneocytes) from the skin surface. As the cells produced by the basal layer move upward, they alter morphologically as well as histochemically to form the outermost layer, the stratum corneum. Over a 4- to 5-week period the entire epidermis is renewed [5]. 

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