Friday, February 16, 2007

Regenerative Medicine--A New Approach to Embryonic Stem Cell Replacement Tissue

Imagine if you will, being able to grow embryonic stem cells to regenerate your failing cells, tissues, and organs--just from your own sperm or eggs. No need to create a fertilised zygote or mated embryo, so there should be no ethical objections from anti-abortion politicians and their constituents.
In the February 15th issue of G&D, Dr. K. John McLaughlin and colleagues report on their success in using uniparental embryonic stem cells to replace blood stem cells in mice. Uniparental embryonic stem cells are an appealing alternative source of patient-derived embryonic stem cells, as they have several advantages over embryonic stem cell lines generated by somatic cell nuclear transfer (also known as therapeutic cloning).

....This study shows for the first time that parthenogenetic blood cells can replace those of an immunocompromised adult mouse. McLaughlin and colleagues also show that this is also possible using embryonic stem cells where both genomes are solely derived from sperm of one male (androgenetic), adding fertile males to the potential patient pool.

....The researchers took a two-step approach: First they injected uniparental ES cells into wild-type blastocyts to generate chimeric animals; then they harvested these chimeric fetal livers for transplant into lethally irradiated hosts. The scientists found that uniparental ES cells, regardless of parent-of-origin, were able to functionally reconstitute the entire hematopoietic system of adult mice. Furthermore, the scientists were also able to grow progenitor blood cells in culture from uniparental ES cells, and upon transplant into irradiated adult mice, show that these cells contribute, long-term, to the function of their hematopoietic system.

In other words, using either only eggs for a female or only sperm from a male, researchers were able to grow embryonic stem cells as replacement blood cell progenitors. These replacement cells functioned and kept the mice alive.

There are still issues of "imprinting" to be worked out when attempting to regenerate different body tissues from asexually produced ESC's. But at least the cells from this approach would be immunologically compatible with the donor. Immunological compatibility is something that sexually produced ESC's cannot guarantee, for purposes of organ regeneration.

Either way, it will be several years before humans can take advantage of this new opening in regenerative medicine.Some feminists had hoped that only females would be able to produce viable ESCs by the asexual method. They had hoped to use that leverage to force males in the US Congress to vote for unlimited funding for nuclear transfer and cloning technologies to produce new stem cell lines.

My question is--why not do both? I am constantly disgusted by the leftists who try to minimize the importance of non-embryonal approaches to creating stem cells, just as I am disgusted by the religious rightists who try to make every technology that deals with haploid cells into an abortion issue.

Unfortunately both groups of closed minded individuals have their own areas of power--where they work to limit our choices. Too bad.


Sunday, February 11, 2007

Mitochondrial Paradigm for ... Aging and Cancer

In looking at aging, it is not enough to look at the nuclear genome. One must also look at the mitochondrial genome, and how the mitochondria interact with the nuclear genome.

Dr. Wallace looks at the ancient history of mitochondria as a free-living organism, and the subsequent symbiosis of mitochondria living inside eucharyotic cells. Then he looks at the mitochondrial genome and how it might affect a person's prospects for a long healthy life. 58 minutes.

Labels: , ,

Friday, February 09, 2007

Kombucha and Probiotics--Symbiotic Foods

Scientists have recently theorized that the necessary chemical and hormonal treatments for extending human lifespan, could be produced by "artificial cells" created to be implantable chemical/pharmaceutical factories. By programming the artificial cells to produce just the right bio-modifying agents at just the right time for a particular individual's needs--most people could avoid doctor's offices and hospitals for long periods of time. Particularly if biosensors that could be queried over wireless networks by the the person's physicians, were also implanted.

But that type of thing is at least a decade in the future. Why not take advantage of tiny chemical factories that are already available, and that could be more easily genetically modified? I am referring of course to "pro-biotics". The lactobacilli found in yoghurt, and similar bacteria prevalent in the mammalian gut, have been very helpful to humans over the decamillenia.

Kombucha is a particularly interesting form of probiotic tea.
The tea contains a symbiosis of yeast species and acetic acid bacteria, mostly Bacterium xylinum. Species of yeast found in the tea can vary, and may include: Brettanomyces bruxellensis, Candida stellata, Schizosaccharomyces pombe, Torulaspora delbrueckii and Zygosaccharomyces bailii. The culture itself looks somewhat like a large pancake, and is often mistakenly referred to as a mushroom.

I was recently introduced to Kombucha by a colleage. Go here for more interesting articles on kombucha.

Bacteria can be made to produce a lot of useful proteins and enzymes, fairly easily. The same is true for yeast. Many of our necessary vitamins are produced in our guts by bacteria. It is time we humans learned to teach our guests how to serve us even better. At this time, the horizons of symbiosis appear to reach a very long way.

Given that these gut bacteria live in the small intestine, beyond gastric acid and gastric proteolytic enzymes, it seems likely that administering peptides via probiotic organisms could be a useful alternative to parenteral administration.
Newer Posts Older Posts