Dear Harold and all,
Interesting paper with which I agree largely though I do feel that some elements of aging are caused by accumulated damage as well as programmed changes. Aging crosslinks, Plaques and other accumulated junk may not be mitigated totally (or at all) even if rejuvenation to a youthful state happens. That said it would go a long way towards health if rejuvenation works as i suspect it may in humans.
A few thoughts:
1: Supply and demmand: How can we create enough supply of Plasma to meet demmand? Identifying, creating and trying to balance all the factors in blood, taking into account their half lives etc… would be very complex compared to using Plasma so what is the alternative? I have seen a proposal for a dialysis type arrangement but again this means blood factors would need to be filtered and balanced. The ideal would be using your own blood rather than relying on others but how realistic is that?
2: Mixed results: I believe an experiment with Plasma in mice yielded inconclusive results not long ago http://ift.tt/1yz01KJ. Admittedly the researchers said it could have been due to the type of Plasma technique used, mouse strain etc… I note they recorded no increase in T-Cell presence which one would expect if the immune system was rejuvenated. Perhaps the frequency of treatment was insufficient or not long enough to create a stable phenotype/environment?
Edouard Debonneuil I believe was involved in the study and I am sure I have seen him active on GRG, perhaps he could comment further?
In contrast other studies showed robust rejuvenation in mice such as shown by Conboy, Wyrss-Corey etc… I believe the Thymus in one study was also rejuvenated though the paper eludes me.
3: Further study: Definately needs further study ideally in Humans plus Plasma is already a safe and approved medical procedure. I would be interested to hear your plan of action Harold and how you think work in this area could move forward.
From: Dr. Harold Katcher To: steve hill ; Gerontology Research Group ; Gerontology Research Group Sent: Wednesday, 25 February 2015, 18:54Subject: Re: [GRG] Newest member Harold Katcher PhD
Hi Steve and all,
Yes there’s no doubt that there are substances that increase and those that decrease during aging in mammals (at least). Both lists of chemicals are however incomplete as we don’t know all of the substances in the blood and have no way of knowing whether they increased or decreased. So for example – membrane-bound ‘exosomes’ – packages of miRNA (important in controlling the extent of translation of messengers) are released into the blood and and taken up by other cells. Those other cells have their behaviors (in terms of translation) changed by the exosomes taken up. So two years ago you might never have heard of miRNA containing exosomes. Do they increase or decrease during aging? That is not even an ask-able question as the contents of those exosomes undoubtedly change during aging – as the miRNA populations are known to change during aging (and in other circumstances as well – like cancer). Are there other things apart from miRNA-containing exosomes that we don’t know about? Who knows (and anyone that assumes they do is making an assumption that many others have made throughout the years and have been shown wrong based on later discoveries of new blood-borne factors). So I wouldn’t presume…. On the other hand there is a way to change old blood so that it exactly mirrors young blood – and preliminary experiments shows that it works to produce rejuvenation. If anyone is interested – and I think this is the real beginning of our ability to control aging – please read my paper, “Studies that shed a new light on aging” at http://ift.tt/1EfWK85 or if that’s no good just do what I did and Google, “Harold Katcher studies that shed a new light on aging” – it comes right up.