| This article discusses the following topics in question | | | | cell, adult stem cells can only reproduce cells of their |
| format on stem cells: | | | | type. If they are muscle cells, they can be used to |
| What are stem cells? | | | | reproduce only muscle cells. However, recent work |
| How are stem cells obtained? | | | | has indicated that some adult stem cells may be able |
| What other potential stem cell sources are there? | | | | to differentiate into other cell types. |
| Why are we and special groups interested in stem | | | | Why are we and special groups interested in stem |
| cells? | | | | cells? |
| What are the goals of stem cell research? | | | | Because stem cells can differentiate, that is, can be |
| How will stem cells affect our future? | | | | used to reproduce other cell types, they have |
| If you are deeply interested in stem cells for the first | | | | tremendous potential for solving many human health |
| time and want to go beyond this article, go to the | | | | problems. |
| National Institute site and read their very | | | | Some groups do not want scientist to take human |
| comprehensive list of frequently answered questions | | | | embryos for research in any way whatsoever. |
| (FAQs). The URL is | | | | Because of this, President Bush restricted stem cell |
| If you are deeply interested in stem cell research, go | | | | research to existing stem cell sources. Other |
| to: | | | | governments have stayed out of the research arena |
| What are stem cells? | | | | and stem cells are collected at the whims of the |
| The question should be phrased in terms of embryonic | | | | scientist. |
| stem cells because that is what we are talking about | | | | Scientists argue that excess stem cells are produced |
| here. | | | | in fertility clinics and that they should be used to benefit |
| A human embryo is obtained when a woman's egg is | | | | mankind. |
| fertilized by a man's sperm. This occurs in the human | | | | So, what do you think? |
| body but it can also be done in a laboratory. The | | | | What are the goals of stem cell research? |
| procedure is often used in cases of infertility. | | | | First, scientists want to understand differentiation. We |
| I have three grandchildren formed in this way. Their | | | | all know that the human embryo creates all the cell |
| mother donated eggs, their father donated sperm, and | | | | types in the human body. Scientists want to know how |
| the technicians watched the fertilization take place | | | | and when genes turn on and off to create a particular |
| under a microscope. The fertilized eggs were placed in | | | | cell type. Abnormal cell divisions cause birth defects |
| the mother and she gave birth to triplets. | | | | and cancer. Scientists want to know what signals a |
| If embryos formed in this way are not placed in the | | | | change in the process of cell development. This could |
| mother they can be and are used for medical | | | | lead to cures for cancer and birth defects. |
| research. Often extra fertilized eggs are produced | | | | Stem cells could be used to test new drugs rather |
| during this process. Scientist would like to harvest | | | | than human guinea pigs and animals. Damage to the |
| these extra eggs rather than discard them. They could | | | | stem cells would eliminate the drug before it could do |
| then use them to obtain stem cells. | | | | damage in the market place, as so many drugs do |
| Stem cells are never obtained from fertilized eggs that | | | | now. |
| reside in a woman's body. | | | | I would like to quote directly at this point: Perhaps the |
| The embryos obtained after they are a few days old | | | | most important potential application of human stem |
| are in the form of a mass of cells called a blastocyst; | | | | cells is the generation of cells and tissues that could be |
| the embryo of about 150 cells. The blastocyst consists | | | | used for Cell-based therapies-treatment in which stem |
| of a sphere made up of an outer layer of cells (the | | | | cells are induced to differentiate into the specific cell |
| trophectoderm), a fluid-filled cavity (the blastocoel), and | | | | type required to repair damaged or depleted adult cell |
| a cluster of cells on the interior (the inner cell mass). | | | | populations or tissues. |
| How are stem cells obtained? | | | | Today, donated organs and tissues are often used to |
| Cell cultures are grown in the laboratory by transferring | | | | replace ailing or destroyed tissue, but the need for |
| the inner cell mass of about 30 cells into a culture dish | | | | transplantable tissues and organs far outweighs the |
| which has a nutrient broth. The cells quickly multiply and | | | | available supply. Stem cells, directed to differentiate into |
| fill the dish. They are then transferred to other culture | | | | specific cell types, offer the possibility of a renewable |
| dishes and the process goes on for months. | | | | source of replacement cells and tissues to treat |
| Once the cells are obtained they can be frozen and | | | | diseases including Parkinson's and Alzheimer's |
| shipped to other laboratories. | | | | diseases, spinal cord injury, stroke, burns, heart disease, |
| What other potential stem cell sources are there? | | | | diabetes, osteoarthritis, and rheumatoid arthritis. |
| Adult stem cells are a potential source. They can be | | | | How will stem cells affect our future? |
| used to reproduce cell of their type. That is, while | | | | Have you heard of the Fountain of Youth? |
| embryonic stem cells can differentiate into any type of | | | | |