Stem Cell Therapy Glossary of Terms

Adult stem cells

Stem cells found in different tissues of the developed, human organism that remain in an undifferentiated, or unspecialized, state. These stem cells can give rise to specialized cell types. Usually derived from adult human blood and re-infused back into the same donor.

Autologous

Derived from the patient’s own body

Bioscience

The science of biology. Human biology and medicine.

Blastocyst

A pre-implantation embryo of about 150 cells. The blastocyst consists of a sphere made up of an outer layer of cells (the trophectoderm), a fluid-filled cavity (the blastocoel), and a cluster of cells on the interior (the inner cell mass). The inner cell mass is where embryonic stem cells are taken from.

Bone Marrow Stromal Cells

A stem cell found in bone marrow that generates bone, cartilage, fat, and fibrous connective tissue.

Brain Natriuretic Peptide

A measurement of this hormone in the blood can determine the presence of and monitor the progress in a patient in cardiac failure.

CD 34 + stem cells

Stem cells found in cord blood that have 10 times the potency of bone marrow stem cells in terms of their proliferation potential. This cell forms the main part of tour treatment regimens. CD stands for “cluster of differentiation” molecule and is the molecule found on the surface of the cell, which enables identification of this cell type.

Cardiac Failure

A condition in which the heart muscle deteriorates progressively until the heart cannot pump effectively and blood collects in the vascular system. Water oozes out of the blood and congests organs. This condition causes breathlessness, fatigue and palpitations and is an extremely unstable cardiac state if not controlled. It cannot be cured and generally deteriorates over time, dependent on the cause.

Cell

The cell is the basic structural and functional unit of all living organisms. Some organisms, such as bacteria, are unicellular (consist of a single cell), humans are multicellular. (Humans have an estimated 100 trillion

cells)

Cell Culture

Growth of cells in a laboratory on an artificial medium for experimental research.

Cell Division

Method by which a single cell divides to create two cells. This continuous process allows a population of cells to increase in number or maintain its numbers. Stem cells which may be few in number on collection may be cultured using this principal to increase their numbers. Also called “expansion”.

Cell Based Therapies

This is the treatment in which stem cells are induced to differentiate into the specific cell type required to repair damaged or depleted adult cell populations or tissues. Many degenerative diseases, as well as damage to organs, may be treated this way.

Cell Type

A specific subset of cells within the body, defined by their appearance, location and function. E.g. heart cells, liver cells, nerve cells etc.

Cerebral Palsy

Is a persistent brain disorder that presents before the age of 3 and is due to brain damage. It is not progressive and has no treatment except for the symptoms. It effects mainly movement and muscle flexibility, but can have cognitive disability and epilepsy. Stem cell therapy seems to elicit a response in more than 90% of these patients under the age of 4. The results in some of these patients have been dramatic.

Culture Medium

The broth that covers cells in a culture dish, in which they may divide and multiply and which contains nutrients to feed the cells as well as other growth factors that may be added to direct desired changes in the cells.

Cytoplasm

The part of the cell surrounding but not including the nucleus. It includes other cell structures called organelles.

 

Degenerative disease

A disease that continuously deteriorates causing increasing disability over time. Diseases like Multiple Sclerosis and Parkinson’s Disease fit this category.

Differentiation

The process whereby an unspecialized early cell acquires the features of a specialized cell, such as a heart, liver, or muscle cell.

Directed differentiation

Whatever processes are needed in manipulating stem cell culture conditions to induce differentiation into a particular cell type. Certain chemicals can force the cells to become pre-defined specialized cells.

DNA

Deoxyribonucleic acid, a chemical found in the nucleus of cells. DNA carries the instructions for making the whole human being. In humans the program is unique to each person.

Echocardiogram

An ultrasound of the heart to determine the ability to pump blood. It is given as a percentage called an ejection fraction. Recent stem cell treatments have significantly improved ejection fraction in cardiac failure patients.

Ectoderm

Upper, outermost layer of a group of cells derived from the inner cell mass of the blastocyst. Ultimately as the foetus develops this layer gives rise to skin, nerves and brain.

Ejection fraction

The measurement of the left ventricle’s ability to pump blood and is a good predictor of longevity in patients. It needs to be above 55% in females and above 63% in males.

Embryo

In humans, the developing organism from the time of fertilization until the end of the eighth week of gestation, when it becomes known as a foetus.

Embryoid bodies

Bundles of cells that form when embryonic stem cells are cultured.

Embryonic Stem Cell lines
Embryonic stem cells, which have been cultured in the laboratory and carry on proliferating without differentiation for long periods, even years.

Embryonic Stem Cells
Undifferentiated cells from the embryo that have the potential to become a variety of specialized cell types. Also called ES cells, embryonic stem cells are cells derived from the inner cell mass of developing blastocysts. An ES cell is self-renewing (can replicate itself) and is pluripotent (can form all cell types found in the body.) They have not been used on patients and are surrounded with controversy.

Endoderm
Lower layer of a group of cells derived from the inner cell mass of the blastocyst; it gives rise to lungs and digestive organs.

Foetus
A developing human baby evolved from the embryo at about two months after conception and continues to birth.

Haematopoietic Stem Cell
A stem cell from which all red and white blood cell develop. The precursors of mature blood cells that are defined by their ability to replace the bone marrow system, following damage or disease, and are able to continue producing mature blood cells. Now commonly recognized as stem cells collected from the peripheral blood.

Haematopoietic Stem Cell Transplantation
The transplantation of haematopoietic stem cells which have the ability to form blood. Haematopoietic stem cells provide rapid and sustained reconstitution of blood formation and are found in adult bone marrow, umbilical cord blood, peripheral blood and in the fetal liver.

Heterologous
Not uniform. In the context of cells, heterologous is a mixed or divergent cell population or cells from diverse sources.

Homologous
Similar or uniform.

Immune system ablation
The destruction of the patient’s immune system by medication, in order to create a “compartment” (blood space) for new cells to fit into and to minimize rejection risk. This carries a significant risk of mortality and is unnecessary in certain conditions. Diseases that were previously treated after ablation, now respond to stem cell therapy without this procedure.

Immune system modulation
The response of the immune system, sometimes to mesenchymal stem cells, that is characterized by reduction of immune system over-activity and significant amelioration of the affected disease state.

Inner cell mass
The cluster of cells inside the blastocyst. This is a small group of cellsattached to the wall of the blastocyst (the embryo at a very early stage of development that looks like a hollow ball). Embryonic stem cells are made by isolating and culturing the cells that make up the inner cell mass. It is the inner cell mass that will eventually give rise to all the organs and tissues of the future embryo and foetus, but do not give rise to the extra-embryonic tissues, such as the placenta.

In Vitro
Literally, in glass; in a laboratory dish or test tube; an artificial environment outside the body.

In Vitro Fertilisation
To assist reproduction in women who are unable to conceive normally, fertilization is accomplished outside the body artificially in a laboratory.The so-called test tube baby.

Mesenchymal stem cells
Mesenchymal stem cells are a type of cell capable of differentiating into various non-haematopoietic tissues. Cord blood-derived mesenchymal stem cells have demonstrated ability to differentiate into a wide variety of tissues in-vitro including neuronal, hepatic, osteoblastic, and cardiac. An important aspect of this cell population is their anti-inflammatory and immunomodulatory activity, which can prove effective in auto-immune disorders.

Mesoderm
Middle layer of a group of cells derived from the inner cell mass of the blastocyst. The middle of three germ layers, it gives rise later in development to such tissues as muscle, bone, and blood.

Mitosis
The process by which a cell duplicates its chromosomes to generate two, identical cells.

Morphology
Study of the shape and visual appearance of cells, tissues and organs.

Multiple Sclerosis
This is a chronic inflammatory autoimmune disease of the central nervous system. It causes plaque-like lesions of the brain and spinal cord, which can occur anywhere. The most common type, relapsing remitting is the only type that can be treated. There is no cure and can be progressively disabling. It has been found that the earlier a patient receives stem cells for this condition, the better the outcome of the treatment, if there is a response. The more disabled patient will have more nerve damage to repair. It seems as if 8 out of 10 MS patients respond to stem cell therapy and booster doses might be necessary.

Multipotent Stem Cells
Stem cells whose progeny are of multiple differentiated cell types, but all within a particular tissue, organ, or physiological system. For example, blood-forming (haematopoietic) stem cells are single multipotent cells that can produce all cell types that are normal components of the blood.

Neural Stem Cell
A stem cell found in adult neural tissue (nerve tissue).

Neurodegenerative Diseases
Diseases of the nervous system characterised by gradual and progressive loss of neural tissue resulting in increasing debility. These are the diseasesmost commonly treated with stem cells.

Oligopotent Progenitor Cells
Progenitor cells that can produce more than one type of mature cell. An example is the myeloid progenitor cell which can give rise to mature blood cells of different types.

Parkinson’s Disease
This disease affects about 1% of all people over 55 years of age and is due to degeneration of a portion of the brain. It is characterised by tremor, slowness of movement, rigidity and a progressive course which can eventually result in dementia and death. There is treatment for the symptoms of the disease, but no cure. It seems as if 7 out of 10 Parkinson’s patients respond to stem cell therapy and booster doses might be necessary.

Placenta
The vascular organ that develops during pregnancy, sticking to the uterine wall and connecting to the fetus by the umbilical cord. Following birth, the placenta is expelled. It contains blood derived from the embryo, i.e. made by the fetus. It is from this blood that umbilical  cord blood cells are taken. The placenta does not allow the mother’s cells to enter its circulation, but allows nutrients and oxygen through.

Plasticity
A phenomenon used to describe a cell that is capable of becoming a specialized cell type of different tissue. For example, when the same stem cell can make both new blood cells and new muscle cells. This is a most important quality of stem cells if they are to be used in therapy.

Pluripotent Stem Cells
Stem cells that can become all the cell types that are found in an implanted embryo, fetus, or developed organism. However these stem cells cannot become extra embryonic cells such as those in the placenta.

Progenitor cell
A progenitor cell, often confused with stem cell, is an early descendant of a stem cell that can only differentiate, but it cannot renew itself anymore. In contrast, a stem cell can renew itself (make more stem cells by cell division) or it can differentiate (divide and with each cell division evolve more and more into different types of cells). A progenitor cell is often more limited in the kinds of cells it can become than a stem cell. In scientific terms, it is said that progenitor cells are more differentiated than stem cells.

Somatic Cells
Another name for adult stem cells and all the cells within the developing, or developed, organism with the exception of germline (egg and sperm) cells.

Somatic Nuclear Transfer
A technique in which the nucleus of a somatic cell (any cell of the body except sperm cells and egg cells) is injected, or transferred, into an egg, that has had its nucleus removed. If the new egg is then implanted into the womb of an animal, an individual will be born that is a clone. The clone has the identical genetic material as the somatic cell, which supplied the nucleus that carries the genetic material.

Regenerative medicine
A new branch of medicine that involves cosmetic, natural, physical and biological methods to fight the effects of aging. This form of medicine often utilizes treatments in which stem cells are induced to differentiate into the specific cell type required for medical interventions that aim to repair damaged organs.

Stromal cells
Non-blood cells derived from blood organs, such as bone marrow or fetal liver, which are capable of supporting growth of blood cells in vitro. Stromal cells that make this matrix within the bone marrow are also derived from mesenchymal stem cells.

Therapeutic cloning
Somatic cell nuclear transfer for the isolation of embryonic stem cells. The embryonic stem cells are derived from the blastocyst (before it becomes a fetus) and can be instructed to form particular cell types (e.g. heart muscle) to be implanted into damaged tissue (e.g. heart) to restore its function. If the stem cells are placed back into the individual who gave the DNA for the somatic cell nuclear transfer, the embryonic stem cells and their derivatives are genetically identical and thus immunocompatible (they will not be rejected).

Totipotent stem cells
Stem cells that can give rise to all cell types that are found in an embryo, fetus, or developed organism, including the embryonic components of the trophoblast and placenta required to support development and birth. The zygote and the cells at the very early stages following fertilization (i.e., the 2-cell stage) are considered totipotent.

Transdifferentiation
The ability of a particular cell of one tissue, organ or system, including stem or progenitor cells, to differentiate into a cell type characteristic of another tissue, organ, or system; e.g., blood stem cells changing to liver cells.

Transplantation biology
Transplantation biologists investigate scientific questions in order to understand why foreign tissues and organs are rejected, the way transplanted organs function in the recipient, how this function can be maintained or improved, and how the organ to be transplanted should be handled to obtain optimal results.

Umbilical cord
The flexible cord-like structure connecting a fetus at the abdomen with the placenta and containing two umbilical arteries and one vein that transport nourishment to the fetus and remove its wastes. It contains blood derived from the embryo, i.e. made by the fetus.

Umbilical Cord Cells
Stem cells are present in the blood of the umbilical cord during and shortly after delivery. These stem cells are in the blood at the time of delivery, because they move from the liver, where blood-formation takes place during fetal life, to the bone marrow, where blood is made after birth. Umbilical cord stem cells are similar to stem cells that reside in bone marrow, and can be used for the treatment of leukemia, and other diseases of the blood. However recent research has shown that umbilical cord blood cells may be proliferated and induced to differentiate into a wider range of cell types thus treating a greater range of diseases which will respond to these umbilical cord cells. The extraction of umbilical cord cells causes no discomfort or change to the mother or baby and the cells are therefore free of any moral restraints.

Unipotent stem cells
Stem cells that self-renew as well as give rise to a single mature cell type; e.g., spermatogenic stem cells. It has now been determined that these cells can also differentiate into other types of cells.

Zygotes
The cell that results from the union of sperm and egg during fertilization. Cell division begins after the zygote forms.