Terminology

  • Adult stem cells : Non-embryonic, undifferentiated stem cells. These cells are found, among other tissues, in bone marrow, adipose tissue, umbilical cord blood, and others. (They are also known by their differentiation capacity as pluripotent, totipotent, and multipotent.) All non-embryonic stem cells are considered adult stem cells.
  • Identical : Refers to a procedure in which the donor is a different individual from the recipient, which is why it is essential to pay attention to tissue compatibility to avoid graft-versus-host disease.
  • Bone marrow stem cells : Adult stem cells obtained from bone marrow.
  • Autologous : Refers to the process in which the donor and recipient are the same person, making them compatible.
  • Cell therapy : Refers to treatments that focus on regenerative medicine to repair damaged or destroyed tissue.
  • Cord blood stem cells : Adult stem cells extracted from umbilical cord blood at birth. These stem cells travel from the liver (where blood is produced during fetal life) to the bone marrow (where blood is produced after birth). They are typically used to treat leukemia and other blood diseases in children, and most cases have been in siblings.
  • Embryonic stem cells : Stem cells extracted from a fertilized egg (blastocyst) two days after fertilization and before cell differentiation. Embryonic stem cells have the ability to differentiate into any type of embryonic tissue.
  • Differentiation : The process by which a stem cell acquires the characteristics of a specialized cell lineage and becomes a specific tissue cell.
  • Good Manufacturing Practices (GMP) : These are quality standards that ensure that products and processes meet the highest quality standards and comply with product or process requirements.
  • Hematopoietic stem cells : Stem cells committed to blood cells (red blood cells, white blood cells, platelets).
  • Human leukocyte antigen (HLA) testing: A human histocompatibility test, which identifies markers of an individual’s immune system. Through this system, the body distinguishes its own cells from foreign cells/tissues. HLA tests aim to determine tissue compatibility between individuals. When six markers match between two individuals, they are considered ideally matched. In transplantation/treatment, a perfect match is essential, but there are exceptions where a 5/6 or even a 4/6 match may be considered satisfactory, depending on the patient, the disease, and the source of the stem cells used.
  • Pluripotent stem cells : Stem cells that can divide into more than one type of cell line.
  • Plasticity : The ability/flexibility of a stem cell to differentiate into other types of cell lines.
  • Pluripotent stem cells : Stem cells that can differentiate into almost any class of cell lines.
  • Potential : The ability to differentiate into specific tissue cells. They are classified as unipotent, multipotent, and totipotent, depending on the number of cells they can differentiate into.
  • Mesenchymal stem cells (also known as stromal cells) : A group of bone marrow stem cells that are not specialized to produce blood cells. Mesenchymal stem cells have the ability to grow and multiply into different cell types.
  • Protocol : A set of procedures, methods, and adherence to specific, planned, and organized traditional rules for a process, intended to regulate behavior in a particular situation.
  • Progenitor stem cells (or unipotent stem cells) : These are stem cells capable of differentiating into a single cell type. At the end of a long series of cell divisions, “fully differentiated” cells emerge, such as liver or lung cells, and are permanently committed to performing specific functions in those tissues. This leads to tissue regeneration and serves as the body’s repair system. These cells persist with the organism throughout its life.
  • Regenerative medicine : A treatment in which stem cells are coaxed to divide into the specific type of cells needed to repair damaged or destroyed tissue.
  • Research protocol : A set of information that defines the objectives, design, methodology, and considerations to be taken into account in conducting and organizing scientific research. This includes examining and interpreting the results, presenting the background and rationale for the research, and defining the criteria by which its results will be measured.
  • Stem cells : progenitor cells capable of growing on their own (indefinitely) and dividing into cells of specific types.
  • Self-renewing : Refers to the ability to reproduce through many cycles of cell division while maintaining its undivided state.
  • CD34 stem cell : A hematopoietic stem cell with a particular molecular structure that displays a characteristic surface marker (CD stands for cluster marker and the number 34 refers to the type of marker displayed by true stem cells).
  • Pluripotent stem cells : These are stem cells capable of dividing into all cell types in the body and of forming an entire organism. The sample is a fresh fertilized egg cell.
  • Unipotent : Stem cells that can divide into one type of cell.
  • Tissue engineering : Refers to the construction of new tissues based on stem cells. Tissues such as skin or cartilage can be produced outside the body and later transplanted into the patient.