[Texas_Tryhard]

(09-01-2014 02:27 PM)Thomas the Rhymer Wrote:  

(09-01-2014 01:49 PM)Texas_Tryhard Wrote:  

What you describe is not microchimerism, and this post is full of science words being used to describe things that have no supporting evidence. Research microchimerism a little more before posting about it. Gobblygook.

Wikipedia article on microchimerism, focusing more on fetal-maternal transfer:
http://en.wikipedia.org/wiki/Microchimerism

Science article detecting male DNA in female brains:
http://www.plosone.org/article/info%3Ado...ne.0045592

Science article finding microchimerism in females who have never had kids, which leads to hypothesis that semen is the source of the foreign DNA:
http://www.ncbi.nlm.nih.gov/pubmed/16084184

I always appreciate criticism, but I'd appreciate something more constructive than merely calling it 'gobblygook.'

Although I admit that much of what I've written is speculation. It's an interesting hypothesis to me though.

Although I was quite curt, understand that I could spend all day constructively criticizing ideas with no supporting evidence, and I don't like to waste my time doing that unless the opposing party supplied some themselves. Since you have kindly supplied your sources, I'll give a more constructive reply. For the record, I had in fact read the PLoS paper before replying, although I hadn't bothered to download the Science paper, which I've now read.

"Microchimerism (abbreviated Mc) is the presence of a small number of cells that originate from another individual and are therefore genetically distinct from the cells of the host individual."

In this case, you're making the extraordinary claim that haploid cells (or haploid DNA) are somehow able to find its way into a woman's brain (or brain cells) and induce inflammation. The mechanism of microchimerism in the brain is thought to require the unique circumstances of pregnancy to allow for transfer across the blood-brain barrier.

For this 'hypothesis' to hold any possible chance of being true, you should at least have evidence supporting it. In this case, your evidence consists of (in order of the sources you presented):

1. Microchimerism is a thing.
A: I don't dispute this. Microchimerism is in fact a thing.

2. Microchimerism can be found in female brains.
A: I don't dispute this. Microchimeric cell populations were found in females.

3. Not all microchimerism IN CIRCULATING BLOOD can be explained by full-term pregnancies.
A: Agreed.


However, you used these three pieces of evidence to jump into a fantastical hypothesis that has no supporting evidence. The hypothesis relies on a framework made of multiple points that haven't been shown (three which come to mind presented below):

1. Haploid DNA from sperm cells are capable of being inserted into the genome of a human.

2. These cells are then capable of transferring across the blood-brain barrier in the absence of the pregnancy-mediated changes in its filtering capacity.

3. These chimeric cells cause inflammation.
Additional info: In both of these studies, they tested whether microchimerism was more prolific in study subjects with diseases that are disruptions in either autophagy (Alzheimer's disease, although this is a simplification) or inflammation (Rheumatoid arthritis). Alzheimer's disease patients actually had less chimeric cells and there was no difference between patient populations in the rheumatoid arthritis study. Although this hardly rules out anything, it does make inflammation in the brain more unlikely.

Additionally, you can hardly call the author's claims in the Science paper support, and certainly not some hypothesis, just a 'possibility' (their words). They give multiple potential explanations that are much more probable, with evidence suggesting that they actually take place (below quote). And even if sex was a potential explanation, all three of the above points still hold true, because circulating blood is not the same as the brain.

Quote:

"Among women who only had daughters or were nulligravid, one potential explanation for male microchimerism could be a nonrecognized (male) miscarriage. Fetal traffic into maternal blood has been reported as early as 4 to 5 weeks postconception, and recent studies suggest the incidence of early pregnancy loss is much higher than previously thought. A second potential source is from a “vanished (male) twin.” A vanished twin is thought to be a relatively common phenomena resulting from spontaneous resorption of one sac or embryo in a twin pregnancy. Twin loss occurs most often in the first trimester and is usually completely reabsorbed into the placenta without being noticed at birth. A third possibility is from an older male sibling transferred by the maternal circulation to the fetus of a later pregnancy. Another possibility that has not been investigated is whether male DNA can be detected in a woman’s circulation from sexual intercourse without pregnancy."

I can come up with a ton of interesting hypotheses, but before I'd share them with others, I'd at least give them the scrutiny they deserve. After all, not everyone has the benefit of years of study into scientific fields, so if you endeavor to share your thoughts with the forum, you may be the only one qualified to apply the proper skepticism to them. People are relying on your assumed expertise, at least somewhat, and I hope you agree that this is a burden as well as a blessing.