Why don't you just provide sources so I can see where you're coming from.
As for your argument that embryonic stem cells sometimes don't "take", you're right and you're wrong. While it's true that they can be rejected, they're far more plentiful than adult stem cells and can be faster and cheaper to reproduce. It's also true that there are methods being developed to fix this (see HERE (http://en.wikipedia.org/wiki/Somatic_cell_nuclear_transfer) for example). This is why we need to be researching them, rather than coddling to a minority whose objections aren't based in science, but their personal moral interpretations. If the science says that embryonic stem cells are unnecessary, then we should follow the science, but that doesn't appear to be the case.
Here is a quick run-down of some of the reasons that I have been able to find why embryonic stem cells are preferable in some cases to adult stem cells:
Embryonic stem cells...
...are easier to identify and isolate (adult stem cells from adults have not been isolated for all tissues of the body).
...can be grown indefinitely in the lab, and can turn into most of the tissue types in the body, with the potential to cure many diseases.
...are more common, whereas adult stem cells are often present in only minute quantities (roughly 1 in 1,000 cells in bone marrow).
...grow quicker and easier in the lab than adult cells, which are difficult to isolate and purify, and their numbers may decrease with age.
...can be more easily manipulated (they are more plastic).
...have worked with animals, e.g. they have been successful in repairing heart damage in mice. (i.e. "a case of them doing what they were intended to do")
Any attempt to use adult stem cells from a patient's own body for treatment would require that stem cells would first have to be isolated from the patient and then grown in culture in sufficient numbers to obtain adequate quantities for treatment. For some acute disorders, there may not be enough time to grow enough cells to use for treatment. In other disorders, caused by a genetic defect, the genetic error would likely be present in the patient's stem cells. Cells from such a patient may not be appropriate for transplantation.
Adult stem cells may contain more DNA abnormalities, caused by exposure to daily living, including sunlight, toxins, and by expected errors made in DNA replication during the course of a lifetime. These potential weaknesses could limit the usefulness of adult stem cells.
Now, whatever you think of the results of embryonic stem cell research, you must acknowledge that it is more than enough evidence to justify the research. The fact that adult stem cells have been used in therapies is terrific and research on adult stem cells should continue, but that doesn't mean we shouldn't be researching both.
I see a lot of extraordinary claims and not a lot of extraordinary evidence
As for your argument that embryonic stem cells sometimes don't "take", you're right and you're wrong. While it's true that they can be rejected, they're far more plentiful than adult stem cells and can be faster and cheaper to reproduce. It's also true that there are methods being developed to fix this (see HERE (http://en.wikipedia.org/wiki/Somatic_cell_nuclear_transfer) for example). This is why we need to be researching them, rather than coddling to a minority whose objections aren't based in science, but their personal moral interpretations. If the science says that embryonic stem cells are unnecessary, then we should follow the science, but that doesn't appear to be the case.
Here is a quick run-down of some of the reasons that I have been able to find why embryonic stem cells are preferable in some cases to adult stem cells:
Embryonic stem cells...- ...are easier to identify and isolate (adult stem cells from adults have not been isolated for all tissues of the body).
- ...can be grown indefinitely in the lab, and can turn into most of the tissue types in the body, with the potential to cure many diseases.
- ...are more common, whereas adult stem cells are often present in only minute quantities (roughly 1 in 1,000 cells in bone marrow).
- ...grow quicker and easier in the lab than adult cells, which are difficult to isolate and purify, and their numbers may decrease with age.
- ...can be more easily manipulated (they are more plastic).
- ...have worked with animals, e.g. they have been successful in repairing heart damage in mice. (i.e. "a case of them doing what they were intended to do")
- Any attempt to use adult stem cells from a patient's own body for treatment would require that stem cells would first have to be isolated from the patient and then grown in culture in sufficient numbers to obtain adequate quantities for treatment. For some acute disorders, there may not be enough time to grow enough cells to use for treatment. In other disorders, caused by a genetic defect, the genetic error would likely be present in the patient's stem cells. Cells from such a patient may not be appropriate for transplantation.
- Adult stem cells may contain more DNA abnormalities, caused by exposure to daily living, including sunlight, toxins, and by expected errors made in DNA replication during the course of a lifetime. These potential weaknesses could limit the usefulness of adult stem cells.
Source: http://web.archive.org/web/20080201224807/http://www.spinneypress.com.au/178_book_desc.html
Now, whatever you think of the results of embryonic stem cell research, you must acknowledge that it is more than enough evidence to justify the research. The fact that adult stem cells have been used in therapies is terrific and research on adult stem cells should continue, but that doesn't mean we shouldn't be researching both.