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Answer to Embryonic Stem Cell Proponents

The Alliance for Medical Research is one of the embryonic stem cell advocacy groups active in my State, Texas. They’re circulating a flyer around Austin titled, “What Makes Early (A.K.A. “Embryonic”) Stem Cells Different From Adult Stem Cells?” Most of the points in the document are pure spin. Some are incomplete. A few are false.

You can read TAMR’s talking points here.

Regenerative Medicine: WHAT MAKES EARLY (A.K.A. “EMBRYONIC”) STEM CELLS DIFFERENT FROM ADULT STEM CELLS?

1. Adult stem cells have been studied for over 40 years and have been successful in treating diseases of the blood and bone marrow, like leukemia, and lymphomas.

“Every type of stem cell may be useful for injuries but are unlikely to cure most diseases, as underlying causes of uncured diseases are often not known. Stem cells may alleviate the symptoms for several years but not affect the disease process.” (“Adult cells are behind much of stem cell success so far” Jean Peduzzi-Nelson Milwaukee Journal Sentinel Online. Posted: Sept. 2, 2006 Accessed September 6, 2006 http://www.jsonline.com/story/index.aspx?id=489953)

70 Plus diseases are being treated and are in early trials and recruitment of human patients in brain trauma (Dr. Baumgartner in Houston), spinal cord trauma (Dr. Carlos Lima in Portugal), genetic defects in metabolism (Phase II and III patient recruiting under Federally funded research on Kostmann’s Syndrome or Congenital neutropenia as in my granddaughter’s case, Batten’s disease, etc.)

More on the success and treatment in Michael Fumento’s July 18, 2006 rebuttal of the Letter to the Editors at Science Magazine in National Review “Science’s Stem-Cell Scam: It should change its name to Pseudoscience.”

“An article from the May 2006 issue of Current Opinion in Hematology notes that “there is presently no curative therapy” for sickle-cell anemia other than allogeneic hematopoietic stem cell transplantation. “Hematopoietic” means from marrow or blood; “allogeneic” means the cells are from another person. Seminars in Hematology (2004) states, “. . . curative allogeneic stem cell transplantation therapy” has “been developed for sickle cell anemia.” Meanwhile, “. . . curative allogeneic stem cell transplantation therapy [has] been developed for” sickle-cell anemia according to Current Opinions in Molecular Therapy (2003), while “hematopoietic stem cells for allogeneic transplantation” are “currently the only curative approach for sickle cell anemia” observes the journal Blood (2002).”

Parkinson’s has been treated with the patient’s own adult brain neural stem cells in at least one human.

Corneal transplants grown from patient’s own stem cells.

“Researchers in the U.S. and Taiwan used corneal adult stem cells to grow new corneas for patients with previously untreatable eye damage. Adult stem cells were taken from the patients themselves in 16 cases, or a family member for 4 other patients. The cells were then grown in culture before transplantation onto the damaged eyes. Sixteen of the 20 patients had improved vision.” Schwab IR et al. “Successful transplantation of bioengineered tissue replacements in patients with ocular surface disease.” Cornea 19 (2000): 421-426.

2. Early, or embryonic, stem cells were discovered in the United States in 1998. In the few short years since that time, animal studies with human embryonic stem cells have demonstrated their potential by reversing diseases and conditions like diabetes, Parkinson’s, and spinal cord injury.

ESC have been known and used in experiments for much longer, but no human embryonic stem cell **lines** were obtained until Thompson’s work in 1998:

“Embryonic stem (ES) cells were first derived from the inner cell masses of mouse blastocysts in the early 1980s (1, 2). More recently, primordial germ cell cultures were found to give rise to cells with characteristics of ES cells and were designated EG (embryonic germ) to distinguish their tissue of origin (3, 4). ES and EG cells have now been derived from embryos of other mammals, including primates (5-10). Now on page 1145 of this issue, Thomson et al. (11) report the derivation of ES cell lines from human blastocysts.” Science 6 November 1998: Vol. 282. no. 5391, pp. 1061 – 1062

Embryonic stem cells have only been used in animal models and have proven difficult to control. Parkinson’s was treated in an animal model – embryonic/fetal stem cells in mice cause teratomas in 1 in 5 of the animals.

3. Beyond therapeutic uses of early, or embryonic, stem cells, these cells also teach researchers:
1) how to make adult stem cells behave in a more useful way, 2) how particular diseases develop and progress and might be reversed, and 3) how drugs work on disease at a cellular level.
Animal models and non-destructive human stem cell techniques are being used in all of these ways.

4. Adult stem cells are found in some – but not all – body tissues. They have not been identified for every organ system and tissue. Adult stem cells can only become cell types from their own particular organ system. Therefore, adult stem cells can be used to cure only some – but not all – degenerative diseases and conditions.

In fact, most tissues have been found to contain stem cells or to be regenerated by stem cells from the bone marrow and other depositories. We are discovering the stimulating and recruiting factors, as well as other conditions that can induce adult and umbilical cord cells to reprogram. See number 5, below.

5. Unlike adult stem cells, early, or embryonic, stem cells have the potential to become any cell type of the human body. They have the potential to replace any cell damaged by disease or injury.
ESC are hard to control, causing teratomas, differentiating into other cell lines, or developing genetic mutations as they divide.

The research on guiding the development of all types of stem cells toward the desired cells requires specific environments, nutrients and stimulating factors. The research and use in therapy is farther along in animal models and human non-embryonic stem cells. Here’s some examples:
a) Texas researchers at the UT Medical Branch at Galveston worked with NASA and British Researchers to turn umbilical cords into “embryonic-like stem cells.”

b) Researchers in Japan have published results showing how to induce adult mouse cells to reprogram into embryonic-like stem cells, without using oocytes or destroying embryos.

6. The term “embryonic” means that the cells are primitive or early.
“Embryonic” describes the fact that these cells have not yet been committed, or programmed, to become a particular type of cell. They have the potential to become any cell type — scientists call this characteristic “pluripotent.”

Embryonic-like stem cells can be derived from non-embryonic sources. See #5 and the “Glossary,” below.

7. Scientists acquire early, or embryonic, stem cells from two sources. They are derived from leftover fertilized eggs at in vitro fertilization clinics — these eggs are either imperfect or excess and will otherwise be discarded. Early, or embryonic, stem cells also come from a laboratory procedure called Somatic Cell Nuclear Transfer (SCNT) — which does not involve a fertilized egg.
There have been no human embryonic stem cell lines derived by SCNT or cloning. There are reports of stem cell lines from parthenogenesis.
See #5
Human embryonic stem cells require the destruction of an embryo, whether that embryo began by in vitro fertilization, parthenogenesis, or SCNT. All will require perpetual donation of endless numbers of oocytes that must be derived from women, with the hazards of superovulation.

Definition of embryo from the International Society for Stem Cell Research Guidelines (Draft, Summer, 2006),

Definition and use of the term “Embryo”
Embryo: The term “embryo” has been defined and used differently in different biological contexts. Classical embryology has used the term embryo to connote different stages of post-implantation stages of development (e.g. the primitive streak and onwards to fetal stages). Dorland’s Illustrated Medical Dictionary (27th edition,1988 edition, W. B. Saunders Company) provides the definition: “in animals, those derivatives of the fertilized ovum that eventually become the offspring, during their period of most rapid development, i.e., after the long axis appears until all major structures are represented. In man, the developing organism is an embryo from about 2 weeks after fertilization to the end of seventh or eighth week.” An entry in Random House Webster’s College Dictionary reads: “in humans, the stage approximately from attachment of the fertilized egg to the uterine wall until about the eighth week of pregnancy.” However, the nomenclature has now been used generically by modern embryologists to also include the stage of first cleavage of the fertilized ovum onwards to nine weeks of gestation in the human and to term in the mouse. Two, four, and eight cell stages, the compacting morula, and the blastocyst are all more precise terms for pre-implantation embryos. Prior to implantation, the embryo represents a simple cellular structure with minimal cellular specialization, but soon after implantation a defined axis of development called the primitive streak begins to form. After this time twinning of the embryo can no longer occur as there is irreversible commitment to the development of more complex and specialized tissues and organs.(Emphasis is mine)

And, actually, there is an axis that tends to be present from the penetration of zona pellucida by the sperm. If one or two cells are removed, as in PGD, the remaining cells reassemble in the same axes if the embryo remains intact and functioning:

“Other researchers suspect that the sperm’s entry on one side triggers a complete re-organization of the egg’s internal skeleton that then makes cells at different positions in the embryo divide at slightly different times.” (“Your Destiny From Day One,” Nature 418, 14-15 (4 July 2002))

About bnuckols

Conservative Christian Family Doctor, promoting conservative news and views. (Hot Air under the right wing!)

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