Old Spleens Suck (2021)
sarahconstantin.substack.com
sarahconstantin.substack.com
Anyway, I got to the emergency room that evening and there was much debate whether to remove my spleen. They decided not to and instead kept me hospitalized for 10 days and then out of school for 3 more weeks after that waiting for it to heal on its own.
Probably because otherwise the impact causes a rupture and you bleed out too quickly to survive.
Whoever was maintaining that gear failed miserably.
This factoid sounds very suspect. Doesn’t most people who need to activate an ejection seat survive spleen or no spleen? Deaths may occur of course, an ejection is not without risks, but if everyone or nearly everyone with a spleen dies then my understanding of the risk associated with an ejection is seriously miscalibrated.
Also the group of “active military pilots who had their spleen removed” must be a small group, likewise “military pilot who needed to activate an ejection seat” is a small group (but probably a bigger one than the spleenless group). So one would expect that there is almost nobody in the intersection of these two rarefied sets.
Obviously this is all very handwavy reasoning, so who knows. But if you have a source that would be highly appreciated.
It is not uncommon for an ejection to end a pilot’s tactical jet flying days for medical reasons.
This exact thing happened to a friend of mine. Combat-rated Harrier pilot in the RAF. Had to punch out after a bird strike. Came out of the infirmary 4 months later, 1/2 inch shorter, flying career over.
I agree with you on that. But the question here is risk of death, not risk of injury.
I don’t have reliable statistics but found this[1] article which says about ejections: “If you look at statistics around the world, the survival rate is greater than 92 per cent.”
1: https://amp.smh.com.au/education/how-dangerous-is-it-to-ejec...
It seems like a majority of ejections shouldn't be benefited by half a second less time to achieve clearance (or the jet itself could detect altitude and adjust the speed to increase survivability).
I'm guessing this is also a function of trying to achieve lateral separation from the ensuing fireball in a crash but it surprises me rates are so high for injury.
Then you don't have to use enough force to avoid the tail in every case, but merely enough force to avoid the tail in this case, which will normally be far less.
The big benefit of solid fueled rockets is that they are very reliable, and require no maintenance. They are basically a big “candle” composed of a mix of fuel and oxidizer. You can lit it a day after it was made or twenty years later it will work the same.
The liquid fueled options have valves and other moving parts which can jam, corrode and degrade with time. So it would require frequent maintenance and would still be likely less reliable than the solid fueled variety.
Devs, you have to think like the 90s. You are shipping software on a CD or floppy l, with no updates ever. Ever.
You get it right, or you may bankrupt the company.
That is an ejection seat, and the simplier the design, less to QA! And on top of this?
The hardware under your software is possibly decaying, and your software still must work.
Sort of like designing software for an apollo mission.
Spinal injuries are likely and ejections frequently end the flying career of pilots for medical reasons.
What does this have to do with the claim in question?
They claimed “people who survive flight ejections and hitting water at high speed tend to have had their spleens removed”
This implies that if you look at the group of people who survived a flight ejection (over water and hit the water at high speed) you would find that most have no spleen. Do you find this plausible?
Instead it’s genuinely interesting information about how an organ changes over time.
TIL; and of course it is derived from Hippocrates’ theory of humors…it all makes sense in retrospect!
Immune: A Journey into the Mysterious System That Keeps You Alive
by Philipp Dettmer
Also, splenectomy led to some fun times during the pandemic because it was and is somewhat unclear whether being permanently immune-compromised due to a splenectomy applied really only to bacteria and sepsis risk, or possibly to virii like coronovairus too, since antibodies and the things that help you “clear” an infection (including a viral infection?) are also produced in your spleen. In the UK, having had a splenectomy was explicitly listed as a condition for what they called “shielding” during the worst of the pandemic, but in the US it was not considered to be a condition named for early access to a full third dose (rather than a booster) of the vaccine.
Other side effects, not mentioned in this article:
- I now have enormous tonsils, to the point where my uvula hangs at a 45 degree angle, probably because the tonsils are making up for the spleen loss, since they serve a somewhat similar function.
- As another commenter here notes, we basically only have long-term data on splenectomized people’s outcomes because of WWII. The small risk of quick sepsis is always going to be there, and did impact their lifespan. But we don’t have enough recent data, in an age of more available antibiotics, to say if there are other potential problems to look for.
- As for histamine/allergy or autoimmune issues being lessened in mice without spleens —- well, I have the same annoying allergies as everyone else in my family, take Claritin daily, and developed auto-immune antibodies due to celiac and then got the oft-associated thyroid problems. So, a sample size of one here, but a splenectomy didn’t seem to be protective against either of those immune-related outcomes here.
All that being said, I don’t miss having a spleen. It was breaking down my entire (congenitally somewhat mishapen) red blood cell supply as a kid, like a swimming pool filter run amuck, leading to anemia and exhaustion and pallor. And while removing it did not make my blood cells gain a normal shape and size, it completely changed my quality of life.
If true, it would likely be very easy to stop aging (there would likely be some mechanism in cells causing aging that could simply be switched off), but this has not been borne out by research so far, and this is despite the fact that much anti-aging researching assumes it to be true.
The preponderance of the evidence currently seems to support the theory that aging is caused by damage building up over a lifetime.
If aging is caused by built-up damage, how would babies ever come to exist and live normal lifespans? The cell lines that produce new human embryos are millions of years old, yet each newly born human doesn’t face the problems of old age until they are 40+ years old.
When genomic damage gets too significant, and damage occurs to critical genes, individuals do not survive to reproductive age, fetuses are miscarried and aren't born, or embryonic development breaks and it might not even be known that fertilization occurred.
Aren't there also mechanisms that reduce accumulation of genetic damage in gametes compared to the rest of the body? That helps too.
Evolutionary pressure can result in traits being selected over others because the individuals with the un-selected traits frequently fail to pass them on. But the cause and effect isn't so much "we need to survive this, let's devise an adaptation," it's "a certain trait happened to end up providing an advantage." There isn't an intentional aspect to the randomness of genetics.
Why and how would evolution - random mutation and selection pressures - penalize the long-lived? Many past cultures actually did the opposite, and elevated and respected elders, for their roles as knowledge holders and such. So how would being longer lived cause your progeny - who at that point would already be born - to be less prolific?
FWIW my guess is it just didn't matter much. Surviving to 50 was plenty enough to have offspring yet not so long you compete with you grandkids for resources or become too much of a burden. That's already much much longer than most species so if anything evolution has already optimized humans to live fairly long lives. Once that got to be "long enough" there just wasn't enough selective pressure to matter.
The human genome is clearly extremely well preserved and is has not changed all that much in hundreds of thousands of years.
However for an individual human, damage to tissues occurs.
For example, if you lose a tooth, it is not going to grow back even though you still have "tooth genes". And this damage is happening to every system of the body e.g. pretty much everybody has atherosclerosis and eventually all humans will die from it if they live long enough.
To increase human lifespan we have to fix all of this entropic damage, which is not impossible but requires advances in medical technology, such as growing new tissue to replace damaged tissue.
To my knowledge, it's all implicit, resulting from wear and tear, the gradual degradation of DNA because of the nature of chemistry on the surface of the planet, and not because any gene or biological mechanism moves an organism through some programmatic notion of mortality.
This seems true to the extent that given molecular level control of an organism, current knowledge would be sufficient to maintain lifespan to an arbitrary degree. Barring sci-fi nanotechnology, genetics and anti-aging have to figure out more robust repair and damage prevention to extend lifespan.
Yes, telomeres.
Telomeres set a count on how many times a cell can divide before it ceases to divide and becoming old and useless; in humans, the count is 40-60 divisions and then the cell essentially dies.
There may be other timing mechanisms that haven't been discovered as well.
They seem to be quite specifically an anti-cancer measure.
For example, with modern society food availability is high. For example we could eat kale every day. Starving is optional. yet I've read that fasting is the way to metabolize senescent cells, but maybe nobody does it anymore.
As an individual it honestly doesn’t matter that much to me if my cell line continues on. I will still be dead.
Humans, being a social species, might have pushed evolution towards trying to repair a bit more than it should. Older humans can still contribute - sometimes a lot - to the group. Older males can still reproduce in many cases.
With that said, it's possible that long life might have negative effect on resource availability which might affect procreation and child rearing, and might find shorter life-span more advantageous to survival of species.
I think this is a fair point. We're multicellular life forms. We're not 1 living thing, but rather a collection of many living things working together. It could be that some of those living things start to betray each other (for personal gain) which aids in our demise. Just as individual humans can do the same to each other, leading to society's demise. But I'm not sure that means we were designed to self-destruct.
I’m not an expert on such subjects but it seems more closely related to the concepts of evolution to say natural selection does not show preference for abnormally long lived individuals because it is unknown or unimportant at time of procreation which traits lead towards lifetime longevity beyond short term hunter gatherer traits.
This way of thinking is dangerous. This is like saying that there is "planned obsolescence" when in reality products are designed to last a certain period. They are not designed to fail after that period but they are also not designed to last longer than that period. The end result is similar but the intention is totally different.