Multiple Sclerosis: V. What are the similarities and differences between embryonic and adult stem cells?

Current Treatments
BETASERON® (interferon beta-1b) is indicated for the treatment of relapsing forms of multiple sclerosis to reduce the frequency of clinical exacerbations. Patients with multiple sclerosis in whom efficacy has been demonstrated include patients who have experienced a first clinical episode and have MRI features consistent with multiple sclerosis

AVONEX® (Interferon beta-1a) is a 166 amino acid glycoprotein with a predicted molecular weight of approximately 22,500 daltons. It is produced by recombinant DNA technology using genetically engineered Chinese Hamster Ovary cells into which the human interferon beta gene has been introduced. The amino acid sequence of AVONEX® is identical to that of natural human interferon beta.

COPAXONE is the brand name for glatiramer acetate (formerly known as copolymer-1). Glatiramer acetate, the active ingredient of COPAXONE, consists of the acetate salts of synthetic polypeptides, containing four naturally occurring amino acids: L-glutamic acid, L-alanine, L-tyrosine, and L-lysine with an average molar fraction of 0.141, 0.427, 0.095, and 0.338, respectively. The average molecular weight of glatiramer acetate is 5,000 – 9,000 daltons. Glatiramer acetate is identified by specific antibodies.

Rebif® (interferon beta-1a) is a purified 166 amino acid glycoprotein with a molecular weight of approximately 22,500 daltons. It is produced by recombinant DNA technology using genetically engineered Chinese Hamster Ovary cells into which the human interferon beta gene has been introduced. The amino acid sequence of Rebif® is identical to that of natural fibroblast derived human interferon beta. Natural interferon beta and interferon beta-1a (Rebif®) are glycosylated with each containing a single N-linked complex carbohydrate moiety.

Tysabri is a monoclonal antibody that affects the actions of the body's immune system. Monoclonal antibodies are made to target and destroy only certain cells in the body. This may help to protect healthy cells from damage. Tysabri is used to treat relapsing forms of multiple sclerosis.

Gilenya™ is a new class of medication called a phingosine 1-phosphate receptormodulator, which is thought to act by retaining certain white blood cells (lympohcytes) in the lymph nodes, thereby preventing those cells from crossing the blood-brain barrier into the central nervous system (CNS). Preventing the entry of these cells into the CNS reduces inflammatory damage to nerve cells.

Early Symptoms
The most common early symptoms of MS include:
* Tingling * Numbness
* Loss of balance
* Weakness in one or more limbs
* Blurred or double vision

Less common symptoms of MS may include
* Slurred speech
* Sudden onset of paralysis
* Lack of coordination
* Cognitive difficulties

Listed above, the early symptoms. I tend to be a poster child for these. The symptoms that occur later on are too numerous just to list. There will be a link included that will get you to a site where these symptoms are listed and explained. Keep in mind that someone may have some of these or many of these, there is no way to tell.

Multiple sclerosis statistics show that approximately 250,000 to 350,000 people in the United States have been diagnosed with this disease. The life expectancy for people with multiple sclerosis is nearly the same as for those without MS. Because of this, multiple sclerosis statistics place the annual cost of MS in the United States in the billions of dollars. MS is five times more prevalent in temperate climates -- such as those found in the northern United States, Canada, and Europe -- than in tropical regions. Furthermore, the age of 15 seems to be significant in terms of risk for developing the disease. Some studies indicate that a person moving from a high-risk (temperate) to a low-risk (tropical) area before the age of 15 tends to adopt the risk (in this case, low) of the new area and vice versa. Other studies suggest that people moving after age 15 maintain the risk of the area where they grew up.

The National MS Society

Tuesday, October 13, 2009

V. What are the similarities and differences between embryonic and adult stem cells?

Human embryonic and adult stem cells each have advantages and disadvantages regarding potential use for cell-based regenerative therapies. One major difference between adult and embryonic stem cells is their different abilities in the number and type of differentiated cell types they can become. Embryonic stem cells can become all cell types of the body because they are pluripotent. Adult stem cells are thought to be limited to differentiating into different cell types of their tissue of origin.

Embryonic stem cells can be grown relatively easily in culture. Adult stem cells are rare in mature tissues, so isolating these cells from an adult tissue is challenging, and methods to expand their numbers in cell culture have not yet been worked out. This is an important distinction, as large numbers of cells are needed for stem cell replacement therapies.

Scientists believe that tissues derived from embryonic and adult stem cells may differ in the likelihood of being rejected after transplantation. We don't yet know whether tissues derived from embryonic stem cells would cause transplant rejection, since the first phase 1 clinical trial testing the safety of cells derived from hESCS has only recently been approved by the United States Food and Drug Administration (FDA).

Adult stem cells, and tissues derived from them, are currently believed less likely to initiate rejection after transplantation. This is because a patient's own cells could be expanded in culture, coaxed into assuming a specific cell type (differentiation), and then reintroduced into the patient. The use of adult stem cells and tissues derived from the patient's own adult stem cells would mean that the cells are less likely to be rejected by the immune system. This represents a significant advantage, as immune rejection can be circumvented only by continuous administration of immunosuppressive drugs, and the drugs themselves may cause deleterious side effects

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