Mammals can absorb oxygen through their intestines | Hacker News Reader

Mammals can absorb oxygen through their intestines

sciencemag.org

103 pointsinfodocket119 comments

So if you're performing CPR, could it increase the chance of survival if someone else performed mouth-to-anus on the person? Maybe in the future first aid kits won't just come with CPR masks but also anal dilators and a brush.

Only if the airway is blocked to a degree that ventilation through the anus would be more effective

Now this is a quality comment on the speculation of new and advanced technology for saving peoples lives.

It could be more hygienic than with mouth contact, for example if a bicycle tire pump were used.

Such a kit would probably come with a oxygenated liquid enema if the article is to be believed. Even if this is effective it would probably have some pushback from CPR instructors.

I'm thinking it would probably be more of a first responder tool. Something in the ambulance.

There are so many futurama jokes that this article would make possible.

Perhaps some nose clips or a HAZMAT suit?

I wonder how effective this is in humans? Could someone with e.g. burned lungs be saved using this technique?

If so, it sounds like a much cheaper alternative to ECMO in some cases.

It's only a matter of time before this is used as a standard performance enhancement trick for endurance sports. Only saying this half-jokingly.

„It was found that John Doe took liquid-oxygen enema before run, unfairly improving his performance.”

Given that liquid oxygen boils at about -300 F, if John Doe can finish a race after a liquid oxygen enema he deserves first prize for something!

Perhaps a Nobel prize?

With an exploratory spirit and a bit of ambition, all records are beatable if you have LOx and a matchbox

I'm stuck between "RocketMan" and a drunken Joe Mulroy lighting a fart in his dormitory room to escape a dead poker hand. Of course, everyone scattered, to avoid the persistent flame hanging onto Mulroy's shorts, if not the fart itself.

Now you can pant both ways when you run

But the no-pant strategy would be more effective.

Tom Brady secretly discovered this years ago. Deflategate was a distraction from the real scandal: Inflategate.

"Only saying this half-assedly."

FTFY

Scuba diving just became more interesting

brb submitting the "Diving Suppository" to YC

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

I was thinking of the old aspiration of filling up the lungs of divers with the oxygen carrying fluorocarbon fluid (like in Abyss). It was deemed apparently impractical because it's too hard to breath. Well... you don't need to breathe with this.

I imagine a butt plug with two hoses, one for oxygenated fluorocarbon input, the other for output, and a cycle where fluid coming out from the butt will needed to be cleaned and re-oxygenated. The input hose could be long enough to reach the cecum (the end of the colon) and perhaps have additional holes to distribute the oxygenated fluid to the whole colon.

TMI?

I wonder if this causes blooms of facultative anaerobes in the gut (they can use oxygen https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4832419/)

Am I weird for thinking this is a cruel experiment?

I was thinking the same, asphyxiating pigs and mice to time how long until they die is just cruel.

I don't understand how suffocating animals to prove they will die can pass an ethics review.

Not to mention "intestinal scrubbing".

I guess "blowing smoke up your ass" will no longer have a negative connotation

It started off as an allegedly positive thing.

https://en.wikipedia.org/wiki/Tobacco_smoke_enema

I might get downvoted for this, but here it goes:

Lets say that your life depends on intestinal ventilation, and you've got a steady flow of oxygenated fluids going into the uh... places... and you need to go number 2? Is it a race to see how quick you can "go" before you get hypoxic and die? Does the constant flow of oxygenated material flush out any waste? It's like wondering "how does Cat Dog go #2" I suppose. But... really. How does it?

I suspect you're fed intravenously while sitting on your air

Would this somehow be more protective during suspended animation (e.g. during the re-warming stage) than providing a person oxygen via the lungs?

This article is like reading Gulliver's Travels Part III: A Voyage to Laputa, but as a real-life thing. Can't stop laughing!

Don’t know why you were downvoted; there’s a very similar part to this article in the book, except instead of pigs and mice, it’s dogs.

Other parts of that book mention machine-generated texts (with hilarious results). Almost 300 years later, it’s remarkable how relevant much of the lampooning of the sciences (broadly considered) in this book remains!

Can't wait to see this in effect during the next Tour de France.

Seems like "exhalation" would become a problem for riders other than the race leader (at the head of the peloton), although perhaps that is already an unaddressed problem.

but where does the CO2 go? normally it's exhaled via the lungs

Good question. From the original Cell paper at https://www.cell.com/med/fulltext/S2666-6340(21)00153-7

Interestingly, the arterial pressure of CO2 tended to be decreased in the l-EVA group, presumably due to the excellent O2 - and CO2-carrying capacity of perfluorochemicals (50 mL O2/dL and 160–210 mL CO2/dL, respectively), while the arterial pH did not change in our experiment. These results indicate that perfluorochemicals also act as an adsorbent for elevated CO2, indicating a need for future follow-up studies of gas exchange mechanisms.

So, they speculate that some of it is absorbed by the perflourodecalin.

In Russia there is a kid's joke about hedgehog who learned how to breathe with it's ass, then it sat down on a stump and suffocated. I think, kids knew something.

In the UK we say I was so tired I was breathing out my arse. Maybe phrases come from a deeper understanding of ourselves than we imagine. Or Maybe not :-)

I wonder if a surgeon could bypass and isolate from the digestive tract a sufficiently large section of the upper intestine to allow for a person to 'breathe' synthetically for a period of time. Ideally without overly disrupting the digestive process. Could be useful for people waiting for lung transplants or who otherwise can't breath conventionally for an extended period.

I'm curious which PFC they are using. A cursory search indicates that PFCs are hazardous to our health. Benzene in particular.

Benzene is not a PFC as it only contains carbon and hydrogen, not the fluorine that puts the F in PFC. According to Wikipedia [1], "fluoroalkanes are generally inert and non-toxic" and "do not bioaccumulate." That was surprising to me too, but apparently they have many established medical uses, including liquid breathing, which makes this application seem more reasonable.

[1] https://en.wikipedia.org/wiki/Fluorocarbon

Thanks! I misread the chart in the wiki, not realizing benzene was there as a comparison to hexaflourobenzene.

Who new the next-gen oxygen bars would be more akin to fecal transplants?

I'm a mammal.

Not sure if this passes the sniff test.

I only exhale with my intestines.

Two things really stood out in this article. One is how brutal animal experimentation can be. The other is the opening line.

It was the picture that really stood out to me.

I read a lot of medical research papers, and I've been thinking about this recently. Every time I read about a rat being "euthanized" or "sacrificed", when they have neuropathy induced by toxins, when they have limbs amputated, when they have their spine severed... I can't help but pause for a moment and think about that animal.

I wonder if there are any good estimates of how many rats, rabbits, dogs and otherwise are maimed and killed each year for medical (or cosmetic) research. Is there, realistically, anything that would change this?

> It is estimated that the annual use of vertebrate animals—from zebrafish to non-human primates—ranges from tens to more than 100 million.[2] In the European Union, vertebrate species represent 93% of animals used in research, and 11.5 million animals were used there in 2011. By one estimate the number of mice and rats used in the United States alone in 2001 was 80 million.[3] Mice, rats, fish, amphibians and reptiles together account for over 85% of research animals.[4]

https://en.m.wikipedia.org/wiki/Animal_testing

After all this time, I still have no idea how I feel about tortuous animal testing for medical breakthroughs.

It's a trolley problem with an unknown number of people on Track A and an unknown number of animals on Track B.

I don't even know how I feel about replacing animals in these experiments with human violent offenders.

Can we justify experimenting on a known serial killer if the experiment will save a million children's lives in the next 10 years? I don't know.

If an alien species were using us for their medical experiments, under the same circumstances and conditions, then what would I say?

https://en.wikipedia.org/wiki/Trolley_problem

Having read a bit about it, my position is something like:

- Experiments are way too common and mostly have useless/unusable outcomes.

- Ethical standards are basically nonexistent.

- Limited animal testing for serious human conditions (cancer, disease, etc.) is justifiable if great care is taken to maximize the benefits and minimize animal suffering.

In the cases where animal testing is justifiable, I would love to see us start funding care for the remainder of the animal's natural life as part of the grant that funds the original research (at least in the cases where the research itself doesn't cause irreparable suffering or risk exposure of some novel pathogen).

At the height of covid, there were a few pigs that were test subjects for ventilators who, after the experiments ended, were sent to an animal sanctuary. I wish we could cut down on animal research by, say, 90% and the remaining 10% could have similar outcomes as those pigs.

I am also all for protecting animals... until grandma is sick and could be cured only if we experiment a little more on rats. When that happens the life of a rat or a million looks disposable.

The thing is, the overwhelming majority of animal testing is not for saving grandma. It's for testing a new brand of makeup.

I'd rather a thousand cute bunnies go blind (or worse) than one woman's eyesight be harmed by dangerous makeup.

On that I can easily disagree. I'd rather we all say: "this makeup cannot be guaranteed to be safe- either outlaw it, skip it, or take your chances" and keep the bunnies alive and unharmed.

It's the medical breakthroughs where I get uncertain. Cosmetics be damned.

> keep the bunnies alive

Sounds nice, but in the real life those lab bunnies wouldn't even have been breed so they aren't alive in fact

Is it okay to not get everything we want? We have limited resources, especially if your care about humanity (or life in general) continuing on for awhile. I for one enjoy thinking about life thousands, millions of years hence, understanding and accepting that this book will probably close.

> Animal testing is bad and must be stopped

>> Here is some animal testing that is good. Could save lives.

> This is not true animal testing. Most animal testing is for lipsticks. I read it in a pamphlet.

If this sounds familiar to you is because is a classic Not true scotsman's fallacy.

> we justify experimenting on a known serial killer if the experiment will save a million children's lives in the next 10 years?

Without hesitation. A serial killer is someone who believes murder is acceptable and turnabout is fair play. Provided they are actually guilty there is little that is unjustified when dealing with willfully violent actors such as that. Add in now this person who has harmed society can be used to repair it and I can't think of anything more fair in a cosmic sense.

"Don't worry, that willcipriano guy we experimented on and murdered was a known serial killer. Never mind that he was a political dissident or whatever."

This is a thought experiment in the real world you wouldn't know for a fact that ten million children would be saved or if the person is actually guilty but if you did the choice is unambiguous.

> Can we justify experimenting on a known serial killer if the experiment will save a million children's lives in the next 10 years?

Not in a civilized society with a rule of law

Any functioning society would gladly sacrifice a serial killer to save millions of innocent children.

Some closely related cases for thought:

How about experimenting on cell cultures harvested from an adult who was executed by the state?

How about experimenting on cell cultures harvested from an aborted human fetus?

In both cases, the source of the cells doesn't give consent, but their designated caretaker does.

> How about experimenting on cell cultures harvested from an adult who was executed by the state?

Like many, I'm against capital punishment and wouldn't live in a jurisdiction that applies it so this is hard for me to even imagine.

I hope though that the philosophical aspect of the question doesn't distract us from the clear practical differences between killing a human being and using cells harvested in a questionable way.

Look up "Henrietta Lacks"

This is a terminological problem then, because many, many people argue "we" are neither civilized nor ruled by law. Furthermore, you could just write a law that says experimenting on serial killers is legal. You'd have to explain how that suddenly makes such a society uncivil, so either civility is the requirement or the law is the requirement, but not both.

So really, you're saying, "not according to our laws" which wasn't the question. It was a moral philosophical question, so your answer doesn't really address the question. It's not even on the same plane. Your answer is just a glib dismissal of the question's philosophical merit.

Sure, so we can't justify it based on our current laws. To change those laws is indirectly up to the people electing lawmakers. So it's up to people's opinion and how they view people who are convicted of serious serious crimes such as murder. Luckily, at least in the countries that I'm familiar with, people still mostly believe in rehabilitation and do not believe in any kind of eye for an eye punishment so I think we're good there. At least for a while.

I don't know how to bridge the gap here. I think I understand what you're saying. You're saying it's not okay because society has said it isn't. You agree with that.

The question is, why do you agree with that? Is it because society says so, or are you deriving that belief based on some principles. If so, what?

What is the underlying fundamental reason you believe it's not okay. I get the sense you think it's not okay to experiment on them, but I don't understand why you believe that. I don't believe you think that because other people think that in a democratic society. I get the sense that if society changed its mind and legalized it, I think you would still say it's not right. You'd go along with it, but you'd believe it is wrong.

Fair disclosure: I think it's wrong too. I am not disagreeing with your opinion, but I'm digging for the explanation you believe it. I think I know why I also believe it, but I don't want to explain why I do, because I think you're on to something, but you have to discover it within yourself.

Maybe you find a society where they are fine to do human experiments. If the tide turns though when you were doing your experiments make sure you still can escape to Argentina to avoid trial. (although after the fall of junta nowadays Argentina might not be safe anymore). Seems like you are just 80 years to late with that idea.

>Can we justify experimenting on a known serial killer if the experiment will save a million children's lives in the next 10 years? I don't know.

How is that a question? Of course it's justifiable. Valuing the life of someone who only sees humans as play things rather than a collective is silly. Remove them for the greater good.

>If an alien species were using us for their medical experiments, under the same circumstances and conditions, then what would I say?

This can be answered with the same logic. I say this with all seriousness, if you are not a speciesist with a heavy bent towards humanity and our continued survival as a group you should really consider scaling back your empathy for the sake of practicality.

Being found guilty of serial murder implies neither actual guilt nor, if actually guilty, that the murderer views other humans as playthings. A murderer may, in fact, believe they themselves are removing such people from the world.

It’s probably also better if potential jurors don’t have the thought, “Well, I have some doubt but if this guy dies and I’m wrong, at least it’ll do a lot of good.”

The parent comment said "known serial killer". There was no discussion of guilt. I may be wrong about the play thing bit so to revise and be more specific in my stance;

1. If they have no issue with killing people.

2. have killed people

3. will continue to kill people

If all or even most of those victims being people who do not harm others then I'm alright with the murderers being used in experiments or killed themselves.

I don't care about them being found guilty or not, this is hypothetical and there are a number of ways that they could be found guilty when they haven't done it or not guilty when they have. Getting to the point where you can know without a single doubt that they in fact are serial killers is a different matter.

I did not get the sense @newsbinator was trying to remove the question to an entirely hypothetical realm, but stipulating that we somehow have this knowledge with hypothetical 100% certainty is fair enough.

(1) is unknowable. (2) and (3) describe many, many people that are not generally considered to be serial killers (e.g., a soldier). If a 'known serial killer' were experimented on and died, (2) and (3) could also describe the researchers doing the experimentation.

We could modify (1) to say, "...and we have 100% certainty of this." But I guess really not certain what value the question has if we basically require 100% certain knowledge of the events and the internal state of the perpetrator. A 'no' answer would mean 'no' in the real world, too, but a 'yes' answer doesn't really tell us anything about the real world.

For the sake of simplicity, I used "known serial killer" to mean somebody we are certain is a serial killer for whatever reason. Let's say they were at a parade, in front of 100 eye-witnesses, and live tv cameras, going around killing people, and then confessed to it to arresting officers and in court.

Somebody who is doubtlessly (and perhaps unrealistically) guilty of committing one of our highest crimes, for the sake of simplifying the question.

> Can we justify experimenting on a known serial killer if the experiment will save a million children's lives in the next 10 years?

I mean, for one thing you can’t breed transgenic killers with a desired genotype by the millions.

> If an alien species were using us for their medical experiments, under the same circumstances and conditions, then what would I say?

That’s too hypothetical. Aliens will be more similar to their native fauna genetically then to us.

Instead of punishing people for crimes they may have not committed (mistakes happen and innocent people go to jail way too often), why not allow altruistic people come forward as volunteers?

I would like to understand downvotes for what seemed like relevant, thoughtful questions posed in this comment.

I had the same thought! Dang repeats the mantra, "bring curiosity" and here is a very curious post being downvoted. Also, the whole point of the downvote is to "disagree" but it doesn't seem to be used that way. Also, down voting limits the ability of the person "disagreed with" to communicate and share their position, which empowers the mob.

And furthermore, even talking about this topic is "meta discussion" which is discouraged here.

What does that say here? Disagreement is suppressed and self-reflection is not appreciated.

Let's just really think about that philosophy. It's an algorithm destined to echo chamber. A lack of diversity of thought.

I would say in the event of experimenting on non-voluntary humans, specifically prisoners, the issue is mostly about the fallibility of the law and setting a dangerous precedent. It's the same reason why the death penalty either needs to be highly restricted or not used altogether. It's too dangerous a power to give to the government lightly due to it's ability to be easily misused or used preemptively.

Other than a solid majority of people being aware of and actively against such practices, I don't see it.

That would cripple science for good and stop the progress. It’s either cancer patients or lab mice.

Yea, every time I receive medical care for some amazing drug or whatever, it crosses my mind of how many animals probably suffered getting it to that point.

And I think maybe we should just call it good right now and stop the experimentation. But that's not really realistic either.

I don't know if there is a good solution :(

That’s why there’s a monument to a mouse [0].

> Is there, realistically, anything that would change this?

In all confidence, nothing is going to replace animal models in science for decades to come(at least when we talk about biology). Yes, you can study development and disease in cell culture or organoids to some extent. But those don’t match the dynamics of a fully-functioning organism. Even though findings from mouse experiments often don’t translate well to humans, it’s our best bet. Computational biology can reduce the amount of experiments you need to do. For example, you can try to predict drug toxicity or identify key regulators of a certain cell type. But there’re always false positives(gene-regulatory networks are like 90% FP) and you always need to go back to the lab.

If anything, I hope for more in-vivo experiments with the developments in CRISPR.

[0] https://en.wikipedia.org/wiki/Monument_to_the_laboratory_mou...

In one group of 11 mice, four had their intestines scrubbed to thin the mucosal lining and improve oxygen absorption. Next, the researchers injected pure, pressurized oxygen into the rectums of the scrubbed mice and four of the seven unscrubbed ones.

I don't even want to know how they do this and whose terrible job this is.

Yea... poor mice.. hopefully they weren't awake.

I have a hunch future generations will look back on our animal experimentation similar to how we look back on human experimentation, horrified but with a silver lining (and most people just prefer not to think about it much at all). I'm very much against both, but I recognize the important advances they've made for medicine. I also recognize that most of the advances for animals don't translate to humans, and some even argue it's slowing progress overall.

https://www.npr.org/sections/health-shots/2017/04/10/5227754...

https://en.wikipedia.org/wiki/Nazi_human_experimentation

Nazi human experimentation was torture done under the auspices of junk-science. It was recognized as such even by the people of that time period.

Nothing that they studied is taught in science programs anywhere today.

My point is many will say the same thing about animal experimentation today. And there are doctors that reference the Nazi experiments, even if most refuse to ever look at the data.

http://www.bu.edu/articles/2019/learn-from-nazi-medical-rese...

While the theories they developed were junk, both Nazi and Imperial Japanese torture experiments play a big role in our modern safety standards and guidelines.

E.g. modern guidelines on how long a human can be safely exposed to cold, or how much blood they can lose were founded on data the USA took from Japanese researches in exchange for pardons.

The japanese experiments on human beings were just as bad or worse: body part swaps, person merging, survival time studies for various death scenarios, there was a lot of extremely messed up stuff.

Yep. I'm not sure how pervasive it is, but there are leaks of medical experiments being done on Uighurs today in China (including experimental coronavirus vaccines).

https://www.independent.co.uk/news/world/asia/china-xinjiang...

https://www.thedailybeast.com/china-forcing-experimental-cor...

I recently read about Shirō Ishii, a Japaneese microbiologist (https://en.wikipedia.org/wiki/Shirō_Ishii) who conducted human experiments during World War-II which resulted in death of close to 10000 humans. More interestingly he was given immunity from war crimes in exchange for full disclosure about his experiments. And the information he provided was deemed invaluable. From the wiki

  it (experiment information) "could never have been 
  obtained in the United States because of scruples 
  attached to experiments on humans," and "the information 
  was obtained fairly cheaply."

Yeah, the animals were put under anesthesia.

> One is how brutal animal experimentation can be

If you think that is brutal you didn't see anything in animal experimentation.

Back when I was a pre-med, my first summer research internship was in a cancer lab. After a couple of weeks of cell culture and autoclaving stuff, they let me start working with the mice. They were inducing lung cancer in them to test some novel compound that was supposed to cure the cancer. Every day, I'd have to go to the mice room, swap in fresh water and food, and then bag all the dead mice individually in rubber gloves, and leave them on my supervisor's desk. Really opened my eyes.

I've always found some solace in not being wasteful. In theory we're working towards a better future - harming animals now will result in world with no harm for an infinite number of descendants later.

This is more or less "do the ends justify the means", but we live in a zero sum universe, so every action we take has to answer this question (if I eat this food, somebody else can't eat it). It's a matter of determining what we think justifies the cost.

I was originally a biology in major in college. In Cell Bio, we had a lab that involved attempting to examine one of the circulatory subsystems of a limpet, but in vivo, so the idea was to chemically paralyze it and then dissect while it was still alive. I am certain to this day that I jacked it up somehow, because that poor limpet was absolutely not paralyzed and was squirming the entire time I was trying to cut it open. This will be seared into my memory for the rest of my life and I never took another biology class after that, only completing a minor instead.

That sounds horrible. :(

> how brutal animal experimentation can be.

Mark Twain expressed it rather succinctly[1]:

"I believe I am not interested to know whether Vivisection produces results that are profitable to the human race or doesn't. To know that the results are profitable to the race would not remove my hostility to it. The pains which it inflicts upon unconsenting animals is the basis of my enmity towards it, and it is to me sufficient justification of the enmity without looking further."

[1] https://books.google.com/books?id=-cq4AQAAQBAJ&pg=PA238

When can we reasonably expect the “cyclist gets banned from tour de france after committee finds athlete installed enteric oxygenation device in the saddle” headline?

Just wait until genetic modification becomes available on the black market. Then things will get really interesting.

Maybe we'll finally start addressing real unearned privilege: genetic. Pro sports players didn't do anything to earn the genetic makeup which accounts for a significant portion of their ability, yet they aren't asked to acknowledge it and take steps to reduce its impact.

>Pro sports players didn't do anything to earn the genetic makeup which accounts for a significant portion of their ability, yet they aren't asked to acknowledge it and take steps to reduce its impact.

Big Harrison Bergeron vibes here.

"In the year 2081, the 211th, 212th, and 213th amendments to the Constitution dictate that all Americans are fully equal and not allowed to be smarter, better-looking, or more physically able than anyone else. The Handicapper General's agents enforce the equality laws, forcing citizens to wear "handicaps": masks for those who are too beautiful, loud radios that disrupt thoughts inside the ears of intelligent people, and heavy weights for the strong or athletic."

In the equality utopia the beautiful ones would have to wear masks, and the strong ones would have to wear weights. So everyone would be equal

This sounds like the opening intro to a dystopian movie.

Thinking of the film "Gattaca" (albeit it was about the opposite of reducing the impact of genetics).

Isn't the point of pro sports to find and admire those incredibly genetically-gifted people? I think trying to inject some kind of pure meritocratic framework into it fundamentally misunderstands the point of sports. To me in a way it's like appreciating a beautiful landscape.

I agree! That's why I watch sports too. But the same arguments you're seeing about X privilege today will come into discussion once genetic editing is more advanced. Instead of rich parents paying for SAT prep, they'll be paying for brain power, height, etc.

Whether your parents paid for it you were born with it, you didn't earn it. We need to re assess why privilege is a bad thing or we need to get ready for an interesting future.

Yet another reason to give up bicycle racing. Back to swimming for me!

So this explains how my scrum master was able to speak about the Agile Manifesto without taking a breath.

>> So this explains how my scrum master was able to speak about the Agile Manifesto without taking a breath.

Well no because to breath the intestines would need air and not be full of $4|7 ;-)

I read it as “scrotum master” at first. Then realized there was no change in meaning.

"My scrum master was just talking out of his ass"

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