The ‘folate trap’
The conversion of 5,10-methylen-THF into 5-methyl-THF, which is catalysed by MTHFR, is irreversible. The only way to make further use of 5-methyl-THF and to maintain the folate cycle consists in the vitamin-B12-dependent remethylation of homocysteine to methionine (regenerating THF). The methyl group transfer is therefore greatly dependent on 5-methyl-THF and the availability of vitamin-B12. In humans, this is the only known direct link of the metabolism of two vitamins; folic acid and vitamin-B12 both need each other.
In cases of vitamin-B12 deficiency, it is possible that, in spite of sufficient availability of folates (and 5-methyl-THF), an intracellular deficiency of biologically active THF arises. This situation is called a ‘folate trap’ (or methyl group trap) because, on the one hand, the concentration of 5-methyl-THF continues to rise but, on the other hand, due to it being prevented from releasing methyl groups, a ‘metabolic dead-end situation’ develops, which leads to the inevitable blockage of the methylation cycle. The co-factors for the C1-transfers decrease and replication as well as the cell division rate are reduced. Hence, the principal problem is the decreasing activity of methionine synthase under vitamin-B12 deficiency with secondary disorders affecting the folate metabolism and insufficient de-novo synthesis of purines and pyrimidines. The deficiency in active folic acids first affects the quickly dividing and highly proliferating haematopoiesis cells in the bone marrow and can even lead to pancytopenia.
Clinically, there is now no difference between vitamin-B12 deficiency anaemia and folic acid deficiency anaemia. If such an anaemia is treated with vitamin-B12, the blockage is immediately stopped and the blood count quickly normalises. However, if the anaemia is exclusively treated with folic acid, it is simply converted to dihydrofolate and THF.
Long-term therapy using high doses of folic acid could therefore conceal the real cause i.e. pernicious (vitamin B12-deficiency) anaemia for a long time. The serum folate continues to rise (congestion of non-regenerated 5-methyl-THF) while the intracellular folate concentration (erythrocytes) drops. This situation interrupts the methylation cycle with numerous cell processes, among them the synthesis of myelin, the nerve fibre lining, being blocked due to a deficiency of methyl groups. A long undetected (causal) vitamin-B12-deficiency can therefore result in serious neurological damage.
Exclusive folic acid therapy can lead to damage progression or even damage irreversibility.
@Wolfwood: Stephen Colbert and Jon Stewart in one post? DOUBLE KILL! I love the Doctor Who GIF. I know a few Who fans I'm sending it to.
And I don't really understand the Methyl Trap/Folate Trap myself. Due to my health I've had to research various things including methylation. I stumbled across those "It's a trap" meme pics and tried to figure out a clever way to post them. Any meme involving Star Wars is full of win. Cookies anyone?
@wolfwood: That guy must have found a glitch in the Matrix because there's no other way that that's possible. I see you edited your post and added more. I was referring to the first GIF where the guy was jumping over all those people.
Yea, quickmeme is making my life difficult. I thought the same thing about the first gif, it's quite a "stretch". Awesome Matrix gifs, that movie is one of my all time favorites. Girls with jet black hair and blue eyes that look like the one up there are my all time favorites. I will now make it my mission to find more hot chick gifs. Here's the other two pics I wanted to put but quickmeme was being gay. xD
I've never had a cat or dog, but I still found that amusing.
Theme for this post is WTF Japan
The nurikabe is a Yōkai, or spirit, from Japanese folklore. It manifests as a wall that impedes or misdirects walking travelers at night. Trying to go around is futile as it extends itself forever. Knocking on the lower part of the wall makes it disappear. It has been suggested that the legend was created to explain travelers losing their bearings on long journeys.
some of them are vocaloids, the robot girl is from
infinite stratos i think maybe, two samurais are from
sengoku basara, ranka and sheryl from macross frontier,
and the grey guy looks like snake maybe, and don't
know about the rest, the asain looking dude in the tower
and the guy with the antlers were the best
Lotus97 said: @one2the: Hey, haven't seen you in awhile
Been studying in China for most of the past year-- where the internet is AWFUL.
lol, how was China besides the crappy internet?
It was very enlightening -- I was able to do a bunch of travelling and studying (I was officially there to do research for my master's thesis), and the whole experience helped me figure out what I want to do for a career.
Lotus97 said: @one2the: Hey, haven't seen you in awhile
Been studying in China for most of the past year-- where the internet is AWFUL.
lol, how was China besides the crappy internet?
It was very enlightening -- I was able to do a bunch of travelling and studying (I was officially there to do research for my master's thesis), and the whole experience helped me figure out what I want to do for a career.
Lotus97 said: @one2the: Hey, haven't seen you in awhile
Been studying in China for most of the past year-- where the internet is AWFUL.
lol, how was China besides the crappy internet?
It was very enlightening -- I was able to do a bunch of travelling and studying (I was officially there to do research for my master's thesis), and the whole experience helped me figure out what I want to do for a career.
So what do you want to do as a career then?
Get a PhD in Education and work in either a government, a school district, or a university on developing curriculum and policy towards creating a more international and foreign student-friendly education system.