Monthly Archives: September 2014

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There are about 360 fertility labs in the U.S. that conduct in-vitro fertilization procedures. They typically extract about 24 ova from each woman client, and fertilize them with a male donor's sperm -- typically her husband's. Two to four of the resultant embryos are then selected and implanted in her womb in the hopes that one will develop and continue a pregnancy to term. Some clinics discard the excess embryos or use them for training purposes. Most clinics deep-freeze the other 20 or so embryos in liquid nitrogen. Some may be used in the future if no pregnancy resulted, and a repeated attempt at impregnation is desired. A few are donated by the couple that "owns" them to another infertile couple. But this is rare, because most clients dislike the idea of having what is in effect their child living in another family. Most become spare, permanently unneeded, frozen embryos .

Past estimates of the number of frozen embryos in the U.S. vary from 100,000 to 188,000. However "experts said that was little more than a guess, and even if it was accurate at one time, it is long out of date now. Plans for what would be the first careful national accounting are being prepared now by the reproductive medicine society." 1

Some clinics keep the embryos alive in liquid nitrogen indefinitely -- or at least until an operator error or equipment malfunction kills them. One source says that about 25% of frozen and thawed embryos do not survive between the first and second impregnation procedure. This loss rate appears to be related to the quality of the freezing and thawing processes, not to the length of time they have remained frozen. If an embryo survives the freezing process, it will probably remain viable for decades. Some have speculated a lifetime of hundreds of years if kept frozen. Experiments on mouse embryos showed no loss in their ability to produce pups after having been frozen for 25 years. Human embryos would probably behave similarly. 13

Other clinics simply discard or destroy the spare embryos. Some embryos are simply flushed down a sink drain. Some are transferred to a medical waste bin where they are later incinerated. Some simply expose the embryos to the air and let them die; this normally takes four days or less.

One source speculates that hundreds of thousands of unused embryos have been destroyed in fertility clinics. 1 This compares to the few dozen of embryos which have had their stem cells removed and used to create stem cell lines in the lab. Surprisingly, nobody seems to care or object. Even pro-life groups appear to be silent on this matter.

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Human stem cell research - Religious Tolerance

Vanderbilt-Ingram Cancer Center performs around 215 stem cell and bone marrow transplants each year, providing care leading up to the transplant, through all aspects of the procedure, and indefinitely after the transplant to monitor for complications. To address some common questions about the procedure, we spoke with Madan Jagasia, M.D., director of the Outpatient Transplant Program and section chief for Hematology and Stem Cell Transplant at Vanderbilt-Ingram.

What is a stem cell? (click to enlarge)

Stem cells or more specifically, in this case, hematopoietic stem cells are cells that can give rise to all the different types of mature blood cells the red blood cells that carry oxygen, the platelets involved in blood clotting, and a host of white blood cells, which are part of the bodys immune system and provide defense against infectious agents. Stem cells are self-renewing (i.e., they can produce more of themselves) and reside primarily in the bone marrow but also circulate in the blood.

For a stem cell transplant, the stem cells can come from a related or unrelated donor, from umbilical cord blood, or from the patient him/herself.

No, these are adult stem cells, from the blood or bone marrow. Even when the source of stem cells is umbilical cord blood, these are still adult stem cells and have nothing to do with embryonic stem cells.

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Understanding Stem Cell Transplant VICC Momentum

Age-related macular degeneration (AMD) is a medical condition which usually affects older adults and results in a loss of vision in the center of the visual field (the macula) because of damage to the retina. It occurs in dry and wet forms. It is a major cause of blindness and visual impairment in older adults (>50 years). Macular degeneration can make it difficult or impossible to read or recognize faces, although enough peripheral vision remains to allow other activities of daily life.

Picture of the fundus showing intermediate age-related macular degeneration.

Starting from the inside of the eye and going towards the back, the three main layers at the back of the eye are the retina, which contains the nerves; the choroid, which contains the blood supply; and the sclera, which is the white of the eye.

The macula is the central area of the retina, which provides the most detailed central vision.

In the dry (nonexudative) form, cellular debris called drusen accumulate between the retina and the choroid, and the retina can become detached.

In the wet (exudative) form, which is more severe, blood vessels grow up from the choroid behind the retina, and the retina can also become detached. It can be treated with laser coagulation, and with medication that stops and sometimes reverses the growth of blood vessels. The is a substantial amount of animal model studies showing that stem cells can reverse and or stabilize the vascularization processes, in the retina.

Although some macular dystrophies affecting younger individuals are sometimes referred to as macular degeneration, the term generally refers to age-related macular degeneration (AMD or ARMD).

Age-related macular degeneration begins with characteristic yellow deposits (drusen) in the macula, between the retinal pigment epithelium and the underlying choroid. Most people with these early changes (referred to as age-related maculopathy) have good vision. People with drusen can go on to develop advanced AMD. The risk is considerably higher when the drusen are large and numerous and associated with disturbance in the pigmented cell layer under the macula. Recent research suggests that large and soft drusen are related to elevated cholesterol deposits and may respond to cholesterol-lowering agents.

Dry AMD

Central geographic atrophy, the dry form of advanced AMD, results from atrophy to the retinal pigment epithelial layer below the retina, which causes vision loss through loss of photoreceptors (rods and cones) in the central part of the eye. No medical or surgical treatment is available for this condition, however vitamin supplements with high doses of antioxidants,luteinandzeaxanthin, have been suggested by the National Eye Institute and others to slow the progression of dry macular degeneration and, in some patients, improve visual acuity.

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Stem Cells Macular DegenerationStem Cell Treatments