Undifferentiated embryonic stem

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... 

Ouyang, A., Ng, R., and Yang, S.-T. 2007. Long-term culturing of undifferentiated embryonic stem cells in conditioned media and three-dimensional fibrous matrices without extracellular matrix coating. Stem Cells 25(2) 447-54. 

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 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. 

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. 

There are several kinds of plant tissues. Undifferentiated, embryonic cells found in rapidly growing regions of shoots and roots form the meristematic tissue. By differentiation, the latter yields the simple tissues, the parenchyma, collenchyma, and scleren-chyma. Parenchyma cells are among the most abundant and least specialized in plants. They give rise through further differentiation to the cambium layer, the growing layer of roots and stems. They also... 

Embryonic stem cell The embryonic stem cell line is typically derived from a male agouti 129/terSv embryo. The cell line must be maintained with meticulous culture procedures to retain normal karyotype and an undifferentiated state. 

As long as embryonic stem cells in culture are grown under certain conditions, they can remain undifferentiated (unspecialized). But if cells are allowed to clump together to form embryoid bodies they begin to differentiate spontaneously into specific cell types (muscle cells, nerve cells, etc.). To generate cultures of specific types of differentiated cells, various growth factors are used in the culture media [45],... 

Embryonic stem cells (ES cells) and homologous recombination are utilized to inactivate an endogenous gene from a host s genome. ES cell lines are derived from a 3-day embryo (ICM cells) and are undifferentiated but remain totipotent. Mouse... 

Fig. 16.1 Both teratocarcinoma cells and normal embryonal stem cells behave alike. Both types of cells are accepted and incorporated into the inner layer of the blastocyst, when they are injected into the blastocyst cavity. They behave like normal embryonic stem cells, and the progeny of these cells are found in practically every cell and tissue of the chimeric mouse, where they differentiate normally. Moreover, they even form normal germ cells. Thus, teratocarcinoma stem cells, when separated from their undifferentiated cancerous daughter cells and transplanted into a compatible host, not only survive, they also do no harm to the host and do not make him cancerous. Incidentally, the capability of embryonic stem cells to be accepted by a recipient blastocyst is the basis of producing gene knock-out, chimeric mice, where a normal gene is replaced by an altered, engineered version of the gene. These chimeric mice then carry the mutation in their stem cells and transmit them to differentiated cells, where they are expressed. (With permission of Taylor and Francis, Inc. See Rg. 21-32 in ref. 1.)...

Stem cells. Embryonic and adult stem cells are distinguished. Embryonic stem cells are taken from an early stage of the embryo, such as from blastocytes. They are undifferentiated and totipotent. Their potential to differentiate and to form different cell lines is unlimited. Adult stemcells are taken from the blood forming bone marrow, from epithelial cells from the skin and other sources. They are pluripotent. Both, embryonic totipotent and adult pluripotent stem cells can replace functionally differentiated cells and tissues in the body. Stem cells can divide. After division, they may form again a stem cell or proceed to a final, fully differentiated state. 

Stem cells normally are classified, based on their origin and differentiation capacity, as either embryonic or adult stem cells (1). Embryonic stem cells (ESCs) are derived from the inner cell mass of the blastocyst. ESCs can self-renew indefinitely and are pluripotent—(the ability to differentiate into all cell types in the embryo proper). Adult stem cells are undifferentiated (unspecialized) cells that are found in differentiated, or specialized, tissue. They have limited self-renewal capability and generally can only differentiate into the specialized cell types of the tissue in which they reside. These cells function as the reservoir for cell/tissue renewal during normal homeostasis or tissue regeneration. Sources of adult stem cells have been found in most tissues, including bone marrow, blood stream, cornea... 

Human embryonic stem cells were first collected in 1998 by two different research teams. The cells obtained from the inner cell mass of the blastocyst (4- to 5-day embryo) are embryonic stem cells (ESC) in contrast, cells cultured from the primordial germ cells of 5- to 9-week fetuses are embryonic germ cells (EGC). In the laboratory, ES or EG cells can proliferate indefinitely in an undifferentiated state but can also be manipulated to become specialized or partially specialized cell types, a process known as directed differentiation. Both ES and EG cells are pluripotent, meaning they have the potential to develop into more than 200 different known cell types. This class of human stem cells holds the promise of being able to repair or replace cells or tissues that are damaged or destroyed by many of our most devastating diseases and disabilities. 

The EST has been developed with the aim to exploit the characteristics and differentiation potential of mouse embryonic stem cells (ES cells), established from the early embryo in 1981 [4, 5], ES cells are cultured in suspension to induce the formation of embryoid bodies, and afterwards they are transferred in 24-well dishes to allow attachment and differentiation in contracting cardiomyocytes. The toxicological endpoint is the inhibition of cardiac differentiation. In parallel a cytotoxicity test is performed on undifferentiated ES cells and a control somatic (fibroblast) cell line (3T3). The concentrations of testing chemicals that induce 50 % of differentiation inhibition (ID50) and 50 % cytotoxicity (IC50) in ES cells and 3T3 cells are inserted in a validated prediction model to classify the test chemical as non-embryotoxic, moderate, or strong embryotoxic [2, 6, 7], The validation of the method has been... 

Bhattacharya B, Cai J, Luo Y, Miura T, Mejido J, Brimble SN, Zeng X, Schulz TC, Rao MS, Puri RK (2005) Comparison of the gene expression profile of undifferentiated human embryonic stem cell lines and differentiating embryoid bodies. BMC Dev Biol 5 22, doi 1471-213X-5-22... 

The therapeutic application of stem cells has long been a dream of medical sciences, but recent discoveries and technical advances have brought this dream much closer to being a reality. Stem cells are usually defined as undifferentiated cells capable of self-renewal, which can differentiate into more than one specialized cell type. Pluripotent stem cells are capable of essentially differentiating into any cell type, whereas multipotent stem cells, often found (be it in low numbers) within specific organs, give rise to lineage-restricted, tissue-specific cell types (see also Part I, Chapter 13). Human embryonic stem cells, harvested from the inner mass... 

The hES cells were shown to fulfill aU the criteria defining embryonic stem cells [28, 29], namely derivation from the pre-or peri-implantation embryo, prolonged undifferentiated proliferation under special conditions, and the capacity to form deri-... 

Richards, M., Fong, C.Y., Chan, W. K., Wong, P.C. Bongso, A. Human feeders support prolonged undifferentiated growth of human inner cell masses and embryonic stem cells. Nat Biotechnol 20, 933-936 (2002). 

Several actions of CNTF reflect its similarity to LIF and IL-6. In vitro, CNTF maintains embryonic stem cells in an undifferentiated state (Conover et al., 1993) and induces the synthesis of acute phase proteins in hepatocytes or hepatoma cells (Schooltink et al., 1992). In vivo, also, CNTF has some of the same actions as LIF and IL-6. Delivered systemically, it is pyrogenic (Shapiro et al.,... 

Stem cells are the precursors of all the other cell types. They are undifferentiated cells that have the ability to form any cell type as well as to replicate into more stem cells. Stem cells are often called progenitor cells because of their ability to differentiate into many cell types. A pluripotent stem cell is one that can give rise to all cell types in an embryo or in an adult. Some cells are called multipotent because they can differentiate into more than one cell type, but not into all cell types. The further from a zygote a cell is in the course of development, the less the potency of the cell type. The use of stem cells, especially embryonic stem (ES) cells, has been an exciting field of research for several years. 

Xu C, Rosier E, Jiang J, et al. (2005). Basic fibroblast growth factor supports undifferentiated human embryonic stem cell growth without conditioned medium. Stem Cells. 23 315-323. 

Stem cells, whether derived from embryos, fetuses, or adults, can be simply defined as progeny of cells that are capable of differentiating into different lineages [152], Embryonic stem cells (ESCs) are isolated from the inner cell mass of blastocysts and have the ability to be cultured and maintained in an undifferentiated and pluripotent state, and directed to differentiate into all specific cell types [153,154], A variety of adult stem cells (often referred as progenitor or multipotent cells), including bone marrow-derived mesenchymal stem cells (MSCs), hematopoietic stem cells (HSCs), adipose-derived stem cells (ADSCs), and neutral stem cells (NSCs), have been found more committed but less pluripotent than ESCs. 

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