First aid for step 1 2021 p50 says, "Hydroxyproline is used for lab quantification of collagen. "

Uworld step 1 QID 638 says that elevated urine levels of Hydroxyproline means there is excess osteoclast activity (collagen is broken down).

So my interpretation is that Hydroxyproline is used for lab quantification of osteoclast activity. Is that correct?

Can anyone link the test or tests to look for collagen degeneration? Would it be hydroxyproline? And what lab? Can it be done at quest or labcorp? Thanks

https://www.youtube.com/watch?v=EbuUwQl9vZA

https://link.springer.com/article/10.1007/s00726-020-02823-6

Important roles of dietary taurine, creatine, carnosine, anserine and 4-hydroxyproline in human nutrition and health

• Guoyao Wu

Amino Acids (2020)Cite this article

• 1024 Accesses
• 46 Altmetric
• Metricsdetails

Abstract

Taurine (a sulfur-containing β-amino acid), creatine (a metabolite of arginine, glycine and methionine), carnosine (a dipeptide; β-alanyl-L-histidine), and 4-hydroxyproline (an imino acid; also often referred to as an amino acid) were discovered in cattle, and the discovery of anserine (a methylated product of carnosine; β-alanyl-1-methyl-L-histidine) also originated with cattle. These five nutrients are highly abundant in beef, and have important physiological roles in anti-oxidative and anti-inflammatory reactions, as well as neurological, muscular, retinal, immunological and cardiovascular function. Of particular note, taurine, carnosine, anserine, and creatine are absent from plants, and hydroxyproline is negligible in many plant-source foods. Consumption of 30 g dry beef can fully meet daily physiological needs of the healthy 70-kg adult human for taurine and carnosine, and can also provide large amounts of creatine, anserine and 4-hydroxyproline to improve human nutrition and health, including metabolic, retinal, immunological, muscular, cartilage, neurological, and cardiovascular health. The present review provides the public with the much-needed knowledge of nutritionally and physiologically significant amino acids, dipeptides and creatine in animal-source foods (including beef). Dietary taurine, creatine, carnosine, anserine and 4-hydroxyproline are beneficial for preventing and treating obesity, cardiovascular dysfunction, and ageing-related disorders, as well as inhibiting tumorigenesis, improving skin and bone health, ameliorating neurological abnormalities, and promoting well being in infants, children and adults. Furthermore, these nutrients may promote the immunological defense of humans against infections by bacteria, fungi, parasites,

I was reading the SDS section 15 for dipalmitoyl hydroxyproline (called Sepilift DPHP on Lotioncrafter), and under "Composition/information on ingredients" it lists "trans-1-(1-oxohexadecyl)-4-[ (1-oxohexadecyl)oxy]-L-proline" with Yes in the column "Immediate (acute) health hazard". I've never heard of Dipalmitoyl Hydroxyproline be even a suspected toxin besides in this sheet. And it doesn't give a reason for why they put yes. Thoughts?

I'm asking because those are the two molecules that vitamin c helps create in order to synthesize collagen. I tried finding research online on this topic without success. This is not a homework question, I'm just curious.

Hey labrats,

Having some issues with a hydroxyproline assay (specifically the MAK008 from Sigma-Aldrich). We use BD Microtainer with a gel separator to get the serum from whole blood. I followed the protocol provided by the assay. 12 N HCl @ 120 C for 3 Hours, mix with activated charcoal, centrifuged and aspirated supernatant into a 96 well plate (~50 ul/well with technical duplicates), dried in a 60 degree oven, mixed with the assay reagents (Chloramine/OX Buffer 5 min @RT, Perchloric Acid/DBMA for 90 min @ 60 C). My standard curve is great (R=0.9998) but when I spike the control samples with 0.4 ug hydroxyproline (from the hydroxyproline standard provided by the kit) there's no real increase in the amount of absorbance at the 560 nm wavelength. Since the assay is typically reported as ug/ul Im concerned thats there is some kind of endogenous inhibitor present but I'm not sure how to clean it up. I've reached out to Sigma but chances are they will give me some canned answer about using a different serum collection or something. Hopefully someone here has some experience with it.

http://www.ncbi.nlm.nih.gov/pubmed/21418016

If anyone can please help!?

Thanks

I don't want to step on anybody's toes here, but the amount of non-dad jokes here in this subreddit really annoys me. First of all, dad jokes CAN be NSFW, it clearly says so in the sub rules. Secondly, it doesn't automatically make it a dad joke if it's from a conversation between you and your child. Most importantly, the jokes that your CHILDREN tell YOU are not dad jokes. The point of a dad joke is that it's so cheesy only a dad who's trying to be funny would make such a joke. That's it. They are stupid plays on words, lame puns and so on. There has to be a clever pun or wordplay for it to be considered a dad joke.

Again, to all the fellow dads, I apologise if I'm sounding too harsh. But I just needed to get it off my chest.

Do your worst!

I'm surprised it hasn't decade.

For context I'm a Refuse Driver (Garbage man) & today I was on food waste. After I'd tipped I was checking the wagon for any defects when I spotted a lone pea balanced on the lifts.

I said "hey look, an escaPEA"

No one near me but it didn't half make me laugh for a good hour or so!

Edit: I can't believe how much this has blown up. Thank you everyone I've had a blast reading through the replies 😂

It really does, I swear!

Because she wanted to see the task manager.

Heard they've been doing some shady business.

BamBOO!

They’re on standbi

Pilot on me!!

Christopher Walken

Nothing, he was gladiator.

Dad jokes are supposed to be jokes you can tell a kid and they will understand it and find it funny.

This sub is mostly just NSFW puns now.

If it needs a NSFW tag it's not a dad joke. There should just be a NSFW puns subreddit for that.

Edit* I'm not replying any longer and turning off notifications but to all those that say "no one cares", there sure are a lot of you arguing about it. Maybe I'm wrong but you people don't need to be rude about it. If you really don't care, don't comment.

What did 0 say to 8 ?

" Nice Belt "

So What did 3 say to 8 ?

" Hey, you two stop making out "

When I got home, they were still there.

I won't be doing that today!

Or would that be too forward thinking?

Where ever you left it 🤷‍♀️🤭

This morning, my 4 year old daughter.

Daughter: I'm hungry

Me: nerves building, smile widening

Me: Hi hungry, I'm dad.

She had no idea what was going on but I finally did it.

Thank you all for listening.

[Removed]

There hasn't been a post all year!

https://link.springer.com/article/10.1007/s00726-020-02823-6

Important roles of dietary taurine, creatine, carnosine, anserine and 4-hydroxyproline in human nutrition and health

• Guoyao Wu

Amino Acids (2020)Cite this article

• 1024 Accesses
• 46 Altmetric
• Metricsdetails

Abstract

Taurine (a sulfur-containing β-amino acid), creatine (a metabolite of arginine, glycine and methionine), carnosine (a dipeptide; β-alanyl-L-histidine), and 4-hydroxyproline (an imino acid; also often referred to as an amino acid) were discovered in cattle, and the discovery of anserine (a methylated product of carnosine; β-alanyl-1-methyl-L-histidine) also originated with cattle. These five nutrients are highly abundant in beef, and have important physiological roles in anti-oxidative and anti-inflammatory reactions, as well as neurological, muscular, retinal, immunological and cardiovascular function. Of particular note, taurine, carnosine, anserine, and creatine are absent from plants, and hydroxyproline is negligible in many plant-source foods. Consumption of 30 g dry beef can fully meet daily physiological needs of the healthy 70-kg adult human for taurine and carnosine, and can also provide large amounts of creatine, anserine and 4-hydroxyproline to improve human nutrition and health, including metabolic, retinal, immunological, muscular, cartilage, neurological, and cardiovascular health. The present review provides the public with the much-needed knowledge of nutritionally and physiologically significant amino acids, dipeptides and creatine in animal-source foods (including beef). Dietary taurine, creatine, carnosine, anserine and 4-hydroxyproline are beneficial for preventing and treating obesity, cardiovascular dysfunction, and ageing-related disorders, as well as inhibiting tumorigenesis, improving skin and bone health, ameliorating neurological abnormalities, and promoting well being in infants, children and adults. Furthermore, these nutrients may promote the immunological defense of humans against infections by bacteria, fungi, parasites, and viruses (including coronavirus) through enhancing the metabolism and functions of monocy