Health Care

By John T Jones, Ph.D.

This article discusses the following topics in question format on stem cells:

What are stem cells?

How are stem cells obtained?

What other potential stem cell sources are there?

Why are we and special groups interested in stem cells?

What are the goals of stem cell research?

How will stem cells affect our future?

If you are deeply interested in stem cells for the first time and want to go beyond this article, go to the National Institute site and read their very comprehensive list of frequently answered questions (FAQs). The URL is http://stemcells.nih.gov/info/faqs.asp.

If you are deeply interested in stem cell research, go to: http://stemcells.nih.gov/info/scireport/.

What are stem cells?

The question should be phrased in terms of embryonic stem cells because that is what we are talking about here.

A human embryo is obtained when a woman’s egg is fertilized by a man’s sperm. This occurs in the human body but it can also be done in a laboratory. The procedure is often used in cases of infertility.

I have three grandchildren formed in this way. Their mother donated eggs, their father donated sperm, and the technicians watched the fertilization take place under a microscope. The fertilized eggs were placed in the mother and she gave birth to triplets.

If embryos formed in this way are not placed in the mother they can be and are used for medical research. Often extra fertilized eggs are produced during this process. Scientist would like to harvest these extra eggs rather than discard them. They could then use them to obtain stem cells.

Stem cells are never obtained from fertilized eggs that reside in a woman’s body.

The embryos obtained after they are a few days old are in the form of a mass of cells called a blastocyst; the 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).

How are stem cells obtained?

Cell cultures are grown in the laboratory by transferring the inner cell mass of about 30 cells into a culture dish which has a nutrient broth. The cells quickly multiply and fill the dish. They are then transferred to other culture dishes and the process goes on for months.

Once the cells are obtained they can be frozen and shipped to other laboratories.

What other potential stem cell sources are there?

Adult stem cells are a potential source. They can be used to reproduce cell of their type. That is, while embryonic stem cells can differentiate into any type of cell, adult stem cells can only reproduce cells of their type. If they are muscle cells, they can be used to reproduce only muscle cells. However, recent work has indicated that some adult stem cells may be able to differentiate into other cell types.

Why are we and special groups interested in stem cells?

Because stem cells can differentiate, that is, can be used to reproduce other cell types, they have tremendous potential for solving many human health problems.

Some groups do not want scientist to take human embryos for research in any way whatsoever. Because of this, President Bush restricted stem cell research to existing stem cell sources. Other governments have stayed out of the research arena and stem cells are collected at the whims of the scientist.

Scientists argue that excess stem cells are produced in fertility clinics and that they should be used to benefit mankind.

So, what do you think?

What are the goals of stem cell research?

First, scientists want to understand differentiation. We all know that the human embryo creates all the cell types in the human body. Scientists want to know how and when genes turn on and off to create a particular cell type. Abnormal cell divisions cause birth defects and cancer. Scientists want to know what signals a change in the process of cell development. This could lead to cures for cancer and birth defects.

Stem cells could be used to test new drugs rather than human guinea pigs and animals. Damage to the stem cells would eliminate the drug before it could do damage in the market place, as so many drugs do now.

I would like to quote http://stemcells.nih.gov/info/basics/basics6.asp directly at this point: Perhaps the most important potential application of human stem cells is the generation of cells and tissues that could be used for Cell-based therapies—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.

Today, donated organs and tissues are often used to replace ailing or destroyed tissue, but the need for transplantable tissues and organs far outweighs the available supply. Stem cells, directed to differentiate into specific cell types, offer the possibility of a renewable source of replacement cells and tissues to treat diseases including Parkinson's and Alzheimer's diseases, spinal cord injury, stroke, burns, heart disease, diabetes, osteoarthritis, and rheumatoid arthritis.

How will stem cells affect our future?

Have you heard of the Fountain of Youth?