The therapeutic uses of stem

cells

Tiasha TalapatraBelise Umuhoza

Sheila KagajuG11A

Biology HL

WHAT ARE STEM CELLS?

An undifferentiated cell of a multicellular organism which is capable of giving rise to indefinitely more cells of the same type, and from which certain other kinds of cell arise by differentiation.

Human embryos consist entirely of stem cells in their early stages, but, gradually the cells in the embryo commit themselves to a pattern of differentiation.

Once committed, a cell may divide several more times, but all of the cells formed will differentiate in the same way and so they are no longer stem cells.

EMBRYONIC STEM CELLS

These are found in a pre-implantation stage embryo.

They multiply extremely fast.

They are multipotent, i.e.. They can develop into any type of cell, tissue or organ in the human body.

ADULT STEM CELLS

An adult stem cell is thought to be an undifferentiated cell, found among differentiated cells in a tissue or organ that can renew itself and can differentiate to yield some or all of the major specialized cell types of the tissue or organ.

Their primary role is to maintain and repair the tissue in which they are found.

These are found in the umbilical cord, fat, bone marrow, etc.

THEORY OF THERAPY

After the stem cells multiply, the healthy cells are separated from the from the diseased cells and reinserted back into the body of the patient.

Human clinical trials show that these new cells go to the diseased or injured body part and begin to generate healthy cells and tissues.

HEMATOPOIETIC STEM CELL TRANSPLANT (HSCT)

Stem cells that give rise to the lymphocytes and other cells of the immune system, also make blood cells, are called hematopoietic stem cells.

HSC’s are characterized by the presence of CD 34 antigen.

The process of taking stem cells from one person and putting them into another is therefore called “ HCST”.

This is used to treat cancer patients with conditions such as leukemia and lymphoma, and sickle cell anemia.

This is used in Providing a functional immune system in a person with SCID.

This is also used in restoring the hematopoietic system.

LEUKEMIA

Stem cells obtained from the placenta can be used to treat patients, especially children, who have developed certain forms of leukemia.

The patient’s blood type is matched with cord blood in the blood bank and if the suitable type is available, the patient is given chemotherapy drugs that kill all bone marrow cells including the ones causing the leukemia.

The selected cord blood is taken and thawed and introduced to the patient’s blood system. The hematopoietic stem cells establish themselves in the patient’s bone marrow, where they divide repeatedly to build up a population of bone marrow cells to replace those killed by the chemotherapy drugs.

STEM CELLS IN TREATING BALDNESS

As hair follicles contain stem cells – derma papilla, they can be used to erase baldness.

The stem cells can be taken from existing hair follicles and multiplied in cultures.

The new follicles can be implanted in the scalp and this will result in the growth of new hair.

DIABETES

Diabetic patients lose the function of their insulin-producing beta cells of the pancreas.

Human embryonic stem cells may be grown in cell cultures and stimulate to form insulin-producing cells , that can be transplanted into the patient

BLINDNESS

Stem cells are taken from a healthy eye and are developed into contact lens in labs.

The lenses are worn by the patient for 3 weeks. Then the the stem cells migrate from the lens to the eye and begin the repair process.

This heals the damaged cornea and improves vision.

MISSING TEETH

The dental pulp of human contains stem cells. These can be taken and cultured in a lab.

Then, the cultured stem cells can be implanted in a tooth bud in gum which then fuses with jaw bone and release chemicals that encourage nerves & blood vessels to connect with gum.

As a result, it will give rise to a new tooth/ dentin within approximately 2 months.

HEART DAMAGE

ETHICAL ISSUES

Human embryonic stem cell are isolated from few days old blastocyst as well as fetal tissues

Many profilers believe that human life becomes a human person at the time of fertilization

Others disagree : they believe that an embryo has potential to develop into a person, but is not a person itself.

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