Jennifer Lewy, Freelance Commercial Writer

Stem Cell Research and Your Health: Current Prospects

One day, stem cell research could treat and prevent an astounding array of ailments—from Parkinson's and Alzheimer's diseases to diabetes and cancer. But because of serious objections to the process of obtaining certain stem cells—a process that involves destroying 5- to 7-day-old human embryos—President Bush halted federal funding of most new stem cell research in 2001. Will treatments based on stem cell research ever make their way into our doctors' offices? And should they?

The Importance of Stem Cells

Stem cells are unspecialized cells that can renew themselves for long periods of time, and when necessary, develop into any kind of cell in the human body. Scientists typically work with two types of stem cells:

• Adult stem cells: In our bodies, adult stem cells stand ready to repair tissue when it is damaged by normal wear and tear or disease.
• Embryonic stem cells: In embryos that are a few days old, embryonic stem cells give rise to all the different cells of the human body.

Why Are Scientists Excited About Embryonic Stem Cells?

Scientists believe that embryonic stem cells offer enormous medical and scientific potential. In the future, embryonic stem cells could be used to replace diseased cells. If scientists can direct stem cells' specialization process, they may be able to use embryonic stem cells to treat a wide range of ailments. For example, Parkinson's disease is a common disorder marked by tremors and loss of muscle control. It is caused by the loss of certain brain cells. Stem cells could be used to replace those lost cells...

Anatomy of the Bones

Bones are made up of three types of tissue: 1) compact tissue, which is the hard outer portion of most bones; 2) cancellous tissue, which is spongy tissue inside the bones that contains bone marrow, which makes blood cells; and 3) subchondral tissue, which is the smooth bone tissue of the joints. A layer of cartilage covers subchondral tissue to cushion the movement of joints.

There are over 200 bones in the human body. They serve several purposes. They support and protect internal organs (for example, the skull protects the brain and the ribs protect the lungs). Muscles, which make the body move, attach to bones. Bone marrow, the soft, spongy tissue in the center of many bones, makes and stores blood cells. Any of these can be affected by bone cancer. However, certain types of bone cancer are more common in specific bones. Osteosarcoma is most commonly found in the bones around the knee. Ewing's sarcoma is more common in the upper leg, pelvis and other bones of the trunk. The pelvis is the most frequent location for chondrosarcoma. Nevertheless, it is possible for these cancers to affect any bone in the body.

I've Just Been Told I Have Bone Cancer

Bone cancer is cancer that begins in your bones. It is also called primary bone cancer. Primary bone cancer is different from secondary bone cancer, which starts in other parts of the body and later spreads to the bones. Virtually all types of cancer can spread to bone. But primary bone cancers are quite rare. They are more common in children and adolescents than in adults.

There are several kinds of cancer that start in the bones. In children and young adults under 30, the most common types are osteosarcoma and Ewing's sarcoma. Osteosarcoma most often develops in the bones around the knees. Ewing's sarcoma usually affects bones in the pelvis and upper leg. In adults, bone cancers include chondrosarcoma which starts in cartilage, chordoma, malignant fibrous histiocytoma of bone and fibrosarcoma of bone. These are all rare in children. There are also a number of other rare types of bone cancer.

Your doctor will use imaging tests and a biopsy to confirm that you have bone cancer, and will recommend additional tests or surgery to help learn how far the cancer has progressed (called the stage).