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Glossary

6 May, 2016 - 09:36

adult (somatic) stem cell — rare undifferentiated cell found in many organs or tissues with limited capacity for self renewal and differentiation. Different cells vary in their differentiation capacity and are limited to organ or tissue specific cell types.

bone marrow stromal stem cells (skeletal stem cells) — a multipotent subset of bone marrow stromal cells able to form bone, cartilage, stromal cells that support blood formation, fat and fibrous tissue.

cell-based therapies — cell-based therapies, including the use of blood formation, fat and fibrous tissue formation.

cell culturein vitro cell division and cell growth in an artificial medium for experimental research.

clone — to generate identical copies of a DNA fragment or genetically identical copies of a cell, or organism. The identical molecule, cell, or organism that results from the cloning process.

  1. In respect to DNA: To clone a gene, a region or fragment of DNA, and make copies of that region using laboratory techniques.
  2. In respect to cells grown in a tissue culture dish: a clone is a cell line that is genetically identical to the originating cell, which is produced by cell division (mitosis) of the original cell.
  3. In respect to organisms: an identical individual clone refers to an animal produced by somatic cell nuclear transfer (SCNT) or parthenogenesis.

differentiation — the process of an unspecialized embryonic cell acquires the features of a specialized cell such as a heart, liver, or muscle cell, which is controlled by the interaction of physical and chemical conditions outside the cell, usually through signalling transduction involving proteins on the cell surface.

embryonic stem cell line — embryonic stem cells, which have been cultured under in vitro conditions that allow proliferation without differentiation for a long period of time.

fetus — the developing human from approximately eight weeks after implantation of an embryo to the uterine wall until the time of its birth.

hematopoietic stem cell — a stem cell that gives rise to all red and white blood cells and platelets.

human embryonic stem cell (hESC) — pluripotent stem cell derived from early-stage human embryos, up to and including the blastocyst stage, which are capable of dividing without differentiating for a prolonged period in culture.

in vitro fertilization — fertilization similar to natural embryonic stem cell.

inner cell mass (ICM) — the cluster of cells inside the blastocyst. These cells will develop to the embryo and ultimately the fetus, which may be used to generate embryonic stem cells.

long-term self-renewal — the ICM cells may be used to generate new cells for long period depending on the specific type of stem cell.

mesenchymal stem cells — a term that is currently used to define non-blood adult stem cells from various tissues. Currently there is no clear information whether mesenchymal stem cells from different tissues are the same.

mitosis (cell division) — a type of cell division that allows a population of cells to increase its numbers with same number of chromosomes remaining.

neural stem cell — a stem cell found in adult neural tissue that can give rise to neurons and glial (supporting) cells, including astrocytes and oligodendrocytes.

neurons — principal functional units of the nervous system, which consists of a cell body and dendrite.

preimplantation — preimplantation means that the embryo has not yet implanted in the wall of the uterus.

proliferation — continuous division of single cells into two identical daughter cells.

regenerative medicine — treatments in which stem cells are induced to differentiate into the specific cell type required to repair damaged or destroyed cell populations or tissues.

reproductive cloning — treatments in which stem cells are induced to differentiate into the specific cell type required to repair damaged or destroyed cell, of which the nucleus is replaced by the somatic cell nucleus. In mammals, this would require implanting the resulting embryo with a substituted nucleus in the uterus, where a living organism with identical genetic makeup of the somatic cell donor is developed. The first animal to be created by reproductive cloning was Dolly the sheep.

somatic cell nuclear transfer (SCNT) — can be used for therapeutic or reproductive purposes, but the initial stage that combines an enucleated egg and a somatic cell nucleus is the same as reproductive cloning.

teratoma — a multi-layered benign tumor that grows from pluripotent cells injected into mice with a dysfunctional immune system, which is used to test whether they have established a human embryonic stem cell (hESC) line by injecting stem cells into such mice, hence to verify the resulting teratomas contain cells derived from all three embryonic germ layers.

therapeutic cloning — production of cells that exactly match a patient by combining a patient's somatic cell nucleus and an enucleated egg. A scientist may harvest embryonic stem cells from the resulting embryo that can be used to generate tissues that match a patient's body and are less likely to be rejected by the patient's immune system.