What is the evolutionary reason for the blood brain barrier? It’s absolutely fascinating. No other organ has this, but you would expect through randomness that it would exist outside of the brain.
Many potential neurotoxins are circulating in our blood, including those from endogenous sources such as metabolites or proteins, or exogenous ones such as xenobiotics ingested in the diet or otherwise acquired from the environment.
I would speculate that other areas of the body haven't developed similar protections because their structures are not as vulnerable to stuff that's floating around in your bloodstream.
The eyes have a similar barrier. I think the current belief is that your body wants to make sure that your T-Cells cannot accidentally nuke your brain and eyes. Those don't grow back and are vitally important, so they have to be protected from the "Nuke it from space" approach of the immune system.
Nit: I’d rephrase to say that your body has no opinions about T-cells. But people who had proto-BBBs survived better than those who didn’t, AND T-cells would nuke the central nervous system from space.
The central nervous system has an extremely delicate chemical environment where routine disturbances like inflammation would induce swelling and destruction of delicate neural pathways. In fact one of the primary roles of the blood-brain barrier is to ensure that any type of “growth” or “organ repair” is extremely retarded - any changes to cells happen very slowly compared to the rest of the body. This is one of the reasons brain damage is so slow to repair, the whole nervous system has a very prescribed way that it grows as a fetus and childhood/youth and then it puts the brakes on everything and only allows very small changes from then on.
They are running a phase 2 trial for this right now (https://clinicaltrials.gov/ct2/show/NCT04528680?term=Sonaben...). It's scheduled to complete in late 2025. Phase 3 will probably be a few years past that, and then probably at least a year or two for approval.
That said, the clinical trial is for the combination of a drug treatment + implantable device. The implantable device itself (Sonocloud 9) has been granted fast track status by the FDA (https://www.fusfoundation.org/posts/cartheras-sonocloud-9-sy...). The fast track status should help speed up how quickly the FDA authorizes the overall treatment once clinical trials are complete.
So... completely pulling a number out of my butt, probably 5-7 years.
It will take 2 of those 5 years just to ascertain at what levels it is safe, and then another two years to determine whether it is better than the current standard-of-care.
While we're all desperate (some more than others) for a break-through in cancer treatment, it seems perfectly reasonable to demonstrate that something is both safe and better than the current standard-of-care before physicians start rolling this out to everyone affected by the brain tumours this therapy would help.
I sympathize with the sentiment that delaying rolling out a therapy like this seems inhumane, it would be no less (and arguably more) inhumane to roll out a therapy where we didn't establish safe doses and effectiveness to the best of our ability. Both potentially result in deaths.
Maybe there are some efficiencies to be found, but we are talking about experimental treatments where the efficacy takes weeks to years to measure. You can't run an overnight benchmarking test.
But in saying that, if a trial is showing very positive results then it can be fast tracked, as it is unethical to withhold that kind of treatment. Conversely, plenty of trials that look good in phase I/II fail in phase III and are terminated early.
To your point, as soon as enough evidence is obtained in Phase III that the drug is better than standard of care, the trial ends early and patients in the trial get switched to it. At least, that was the case in the case studies we looked at in my lectures.
I often see this on news items, but at some point I realized that these names could have been semi-jokingly made up by the video editors who simply didn't have a name to put in the clip (or perhaps they used a placeholder name that never got fixed).
Yes? There are lots of variations of cancer, but it seems to be a well defined set of conditions. I don't think I've ever seen an argument over whether something is or is not cancer, or suggestion that such an argument could be made.
Our current methods of treating it treat it in a piecemeal fashion, targeting one variation or another, but I don't think it's unthinkable that you could managed to target and fix the entire set.
Set is an understatement here, there are about ~200 types (as of now), and within a numerous amount of mutations per person. This is why one person could have been treated effectively with early enough detection, and others it just keeps spreading despite treatment. What's even worse, even if treatment does work, it can eventually stop working due to these mutations.
This is why we deal with it piecemeal, because it's the only way we can actually detect it. This isn't a current technical limitation, this is a "we can't solve something before we know the problem" issue due to how cells work. Even in the very long term future where we have bio implants, the best solution we would have are implants being able to seek cancer cells instantly and remove them.
Humour me for a second and think about this in a "sci-fi we have whatever theoretically possible technology we want" fashion.
Suppose scanning technology progresses to the point where we can quickly resolve every cell in the human body. Suppose computing technology progresses to the point where we can quickly interpret that scan data and identify which areas are normal and which areas are tumorous growths that shouldn't exist. Suppose surgical(/point application of energy) technology progresses to the point where we can destroy any individual cell without collateral damage.
I believe at that point we could solve the entire set of conditions called cancer (but maybe not all disease, maybe some forms of dementia still evade us for instance).
I'm not criticizing the current approach by calling it piecemeal. It's what we know how to do, doing it saves lives, of course we should do it. I'm just saying that cancer is a meaningfully label, and it's conceivable that at some point we can solve it, all of it.
It seems we use ultrasound, for example on every baby, and don't have good data to prove that there are no side effects.
Yet research like this shows that there clearly are biological effects of sufficiently powerful ultrasound.
What if societies lack of future Einstein's is down to blasting the brains of all of them with ultrasound pre-birth?