[ExI] Subject: [New_Cryonet] Fw: [cryo] Fwd: Steve Van Sickle's presentation a

m2darwin at aol.com m2darwin at aol.com
Sat Sep 7 05:12:51 UTC 2013


 
 
-----Original  Message----- 
From: Alejandro Dubrovsky 
Sent: Friday, September 6, 2013  9:53 AM 
To: cryo at postbiota.org 
Subject: [cryo] Fwd: [ExI] Steve Van  Sickle's presentation at SENS6 

-------- Original Message  --------
Subject: [ExI] Steve Van Sickle's presentation at SENS6
Date:  Fri, 6 Sep 2013 01:40:34 -0400
From: Rafal Smigrodzki  <rafal.smigrodzki at gmail.com>
Reply-To: rafal at smigrodzki.org, ExI chat  list
<extropy-chat at lists.extropy.org>
To: ExI chat list  <extropy-chat at lists.extropy.org>

Yesterday I had the pleasure of  attending Steve Van Sickle's
presentation at SENS6, reporting his results  with cryonic preservation
of kidneys. Steve developed a technique for  persufflation of organs
perfused with cryoprotectants using cold helium. He  was able to cool
pig kidneys to liquid nitrogen temperature, achieving  total
vitrification while *avoiding* fractures! I was absolutely floored  by
his work, easily the most important presentation at SENS6 so far.
Steve  also described calculations for hyperbaric persufflation, which
might allow  vitrifying a human body in *a few minutes*! 
There's  only one small problem (at least for me) with this "remarkable 
breakthrough", or  more particularly, with the crediting of it. 
When  Steve Van Sickle was President of Alcor, and Tanya Jones was in 
charge of acute  patient care, I engaged in an extended and frustrating series of 
emails with Van  Sickle, copied to Tanya and to Alcor Director Dr. Brian 
Wowk. The subject of  this correspondence was my urging Alcor to switch to 
using gas perfusion  following cryoprotective perfusion of patients, in order 
to achieve both more  uniform cooling, as well as much faster cooling and 
very possibly the reduction  or elimination of fracturing injury in patients. 
The  reasons I suggested this were not merely theoretical. When I was 
working as a  researcher for Manrise Corporation (Fred and Linda Chamberlain)  in 
the  mid-1970s I had conducted gas perfusion experiments on rabbit kidneys 
and heads  following the work of Schimmel, et al. with gas perfusion of rat 
kidneys; http://www.ncbi.nlm.nih.gov/pubmed/5872343 ,  that of of Hamilton 
and Lehr with gas peerfusion of canine small bowel 
http://www.ncbi.nlm.nih.gov/pubmed/4702169 and  of the work of Guttmann, et al., using hedlium 
perfusion in canine kidneys: http://www.ncbi.nlm.nih.gov/pubmed/1259562 and  
http://jama.jamanetwork.com/article.aspx?articleid=661256 . 
This  work demonstrated that uniform cooling rates on the order of 2-3 deg 
C min were  achievable and, as I noted in my correspondence with van Sickle 
at that time,  there was no evidence of fracturing, even in kidneys loaded 
with 25% w/v  cryoprotectant. 
I  would also point out my extensive discussion of the idea of gas 
perfusion in  cryonics in this post on Cryonet during the "cooling fluids debate" 
that took  place there on 12/17/92: 
http://www.cryonet.org/cgi-bin/dsp.cgi?msg=1465 
I  pointed out that this technique was far easier to implement than was  
perflurochemical (PFC) perfusion and that it had the advantage of having 
already  been proven out from a practical standpoint not only by my work in the  
mid-1970s, but by work done by Pegg, et al., in the in 1978; 
http://www.sciencedirect.com/science/article/pii/001122407890086X .  What's more, 
experiments conducted in recent years using oxygen persufflation of  hypothermically 
(non-frozen) stored organs had demonstrated that putative  problems with gas 
emboli, or endothelial cell dehydration, were, in fact NOT  problems and 
that organs perfused with gas could be transplanted with the  long term 
support and survival of the animals being a uniform  outcome: 

1:  Srinivasan PK, Yagi S, Doorschodt B, Nagai K, Afify M, Uemoto S, Tolba  
R.
Impact of venous systemic oxygen persufflation supplemented with nitric  
oxide gas
on cold-stored, warm ischemia-damaged experimental liver grafts.  Liver 
Transpl.
2012 Feb;18(2):219-25. doi: 10.1002/lt.22442. PubMed PMID:  21987402. 

2:  Minor T, Akbar S, Tolba R, Dombrowski F. Cold preservation of fatty  
liver
grafts: prevention of functional and ultrastructural impairments by  venous 
oxygen
persufflation. J Hepatol. 2000 Jan;32(1):105-11. PubMed PMID:  10673074. 

3:  Stegemann J, Hirner A, Rauen U, Minor T. Gaseous oxygen persufflation  
or
oxygenated machine perfusion with Custodiol-N for long-term preservation  of
ischemic rat livers? Cryobiology. 2009 Feb;58(1):45-51.  doi:
10.1016/j.cryobiol.2008.10.127. Epub 2008 Oct 17. PubMed PMID:  18977213. 

4:  Minor T, Olschewski P, Tolba RH, Akbar S, Kocálková M, Dombrowski F.  
Liver
preservation with HTK: salutary effect of hypothermic aerobiosis by  either
gaseous oxygen or machine perfusion. Clin Transplant. 2002  
Jun;16(3):206-11.
PubMed PMID: 12010145. 

5:  Lauschke H, Olschewski P, Tolba R, Schulz S, Minor T. Oxygenated  
machine
perfusion mitigates surface antigen expression and improves  preservation of
predamaged donor livers. Cryobiology. 2003 Feb;46(1):53-60.  PubMed PMID:
12623028. 

6:  Gong J, Lao XJ, Zhang SJ, Chen S. Protective effects of L-arginine  
against
ischemia-reperfusion injury in non-heart beating rat liver graft.  
Hepatobiliary
Pancreat Dis Int. 2008 Oct;7(5):481-4. PubMed PMID:  18842493. 

7:  Nagai K, Yagi S, Afify M, Bleilevens C, Uemoto S, Tolba RH. Impact  of
venous-systemic oxygen persufflation with nitric oxide gas on steatotic  
grafts
after partial orthotopic liver transplantation in rats.  Transplantation. 
2013 Jan
15;95(1):78-84. doi: 10.1097/TP.0b013e318277e2d1.  PubMed PMID: 23263502. 

8:  Minor T, Isselhard W, Klauke H. Reduction in nonparenchymal cell injury 
 and
vascular endothelial dysfunction after cold preservation of the liver by  
gaseous 
oxygen. Transpl Int. 1996;9 Suppl 1:S425-8. PubMed PMID:  8959878. 

9:  Saad S, Minor T, Nagelschmidt M, Fu ZX, Kötting I, Paul A, Troidl H,  
Isselhard
W. [Revitalizing donor livers after cardiovascular arrest with  venous 
oxygen
persufflation]. Langenbecks Arch Chir Suppl Kongressbd.  1998;115(Suppl 
I):705-8. 
German. PubMed PMID:  14518345. 

10:  Tolba RH, Schildberg FA, Schnurr C, Glatzel U, Decker D, Minor T.  
Reduced
liver apoptosis after venous systemic oxygen persufflation in  
non-heart-beating
donors. J Invest Surg. 2006 Jul-Aug;19(4):219-27. PubMed  PMID: 16835136. 

11:  Sun HW, Shen F, Zhou YM. Influence of perfusion by gaseous  oxygen
persufflation on rat donor liver. Hepatobiliary Pancreat Dis Int.  2006
May;5(2):195-8. PubMed PMID: 16698574. 
Van  Sickle's response was, essentially, to argue that gas perfusion simply 
could not  compete with the exchange capability of a liquid - even a liquid 
with relatively  poor heat carrying capacity, such as a perflurochemical 
(PFC), or a mixture of  PFCs. These remarks were presumably made on the basis 
of a patent by Brian Wowk  and demonstrating the utility  of PFC for 
improving heat exchange during  cooling of organs and whole animals.  
My  efforts to point out to Steve that this technique was severely limited  
because: 
*  Because of the increasing viscosity, and ultimately the solidification 
of the  PFCs at temperatures right around the critical glass transition point 
for M-22,  the ability to remove heat from the patient is lost at precisely 
the point  during cooling when it was most needed. 
*  Perfusion of PFCs was incredibly uneven in the tissues due to a short 
circuiting  effect that occurred when very low viscosity PFC first opened a 
channel of flow  between the arterial and venous circulations. These "first 
opened" channels  effectively "stole" much of the flow from the capillary  
beds. 
*  The PFC proved virtually impossible to remove, proved obstructive to 
subsequent  perfusion and precluded any access to the circulation at storage  
temperatures. 
*  PFC perfusion was logistically very difficult and there were many 
problems with  cryoprotective perfusate continuing to stream out of the animals'  
circulatory systems requiring extensive filtration and multiple trap 
placement  in the PFC perfusion circuit (on both the venous and the arterial  
side). 
Perfusion  circuit of a dog undergoing subzero PFC perfusion cooling  to ~  
-70 deg C in 1995: 
 
Prototype PFC  perfusion cooling and re-warming machine developed at 21CM 
circa  1996: 
 
And lastly, that  pumping PFC through Silastic (silicone rubber) tubing caus
ed the build-up of  dangerous electrostatic charges which, on two 
occasions, resulted in fires in  the operating room and the destruction of the costly 
centrifugal pumps  being used to pump the PFC. One fire had  to be 
extinguished with a CO2 fire extinguished and it caused nearly $2,500  worth of 
damage - not to mention ruining the experiment! These problems were  never 
definitively solved... 
Still, I could not  get through to Van Sickle and I did not receive any  
response from Tanya Jones regarding this matter. 
Shortly  after Peter Thiel funded Van Sickle and Jones' Argo Biomedical in 
February,  2012, I received an email (anonymous) informing me that the 
technology Argos was  developing was being kept "top secret" in large measure to 
avoid a response from  me, like this one. I was informed that the basis for 
Argos' research venture was  the communications from me to Van  Sickle and 
Jones in the mid-2000s. This prompted me to place a call to  Dr. Greg Fahy 
and to ask him if he knew what Argos' research platform was?  His response was 
that he had agreed to keep the matter confidential and that he  intended to 
honor that agreement. 
The  idea of using helium (or other) gas perfusion to increase both the 
rate and  the homogeneity of cooling in organs is not a new one and it did not  
originate with me. While I can fairly take credit for being the first to 
propose  this for use in cryonics, and to be the first to actually apply the  
technique to isolated heads, I have always been careful to credit the  
researchers who originated and first validated the utility of this idea. To  
those who would say that this idea is both obvious and compelling for  
application in cryonics, I would point to the correspondence reproduced below,  
wherein as recently as 2008, I am arguing for adoption of this approach - to no  
avail. 
Reaching  the minimum concentration of cryoprotectants needed to achieve 
vitrification  (CNV) uniformly in human cryonics patients is very difficult 
due to peri- and  post-cardiac arrest ischemia. The result is that substantial 
freezing occurs in  areas of the brain that are not quite at CNV. The 
obvious way to solve this  problem is to eliminate ischemia. But, alas, this is 
not now possible. However  CNV is a function of not just the CPA 
concentration, but also of the cooling rate. Currently, Alcor is  limited to a cooling 
rate of ~ -3 deg C per  hour  for brain and this means that the CNV must be 
very high - well over 60% (v/v).  If that cooling rate could be increased to 
even 0.5 deg C/min, the CNV would be  lower and more of the brain in 
ischemic patients would thus likely undergone  vitrification, as opposed to 
freezing. 
This  is what I argued be done for Alcor patients many years ago. I 
subsequently  repeated this argument to people at CI in 2007-8 - again to no  
avail. 
In  closing I would like to quote Isaac Newton in a letter to Robert Hooke 
on 15  February 1676: 
"If  I have seen further it is by standing on ye sholders of  Giants." 
For  the context of this quote see:  
http://www.newtonproject.sussex.ac.uk/view/texts/normalized/OTHE00101 
Generally,  (but sadly, not always) it is in the character of innovators 
and academics to  generously acknowledge the intellectual lineage of their 
work. Indeed, one of  the reasons that Newton is, to this day, so much more 
beloved and respected than  Robert Hooke, is because he had both the wisdom and 
the personal integrity to  acknowledge that his efforts, Herculean though 
they were, were possible only  because he himself had stood upon the 
shoulders of  giants. 
Mike  Darwin 
  
____________________________________

From:  M2darwin
To: REDACTED
CC: wowk at 21CM.com, gfahy at 21CM.com,  aschwin.de.wolf at gmail.com, 
chana.de.wolf at gmail.com,  m2darwin at googlemail.com
BCC: danila.medvedev at gmail.com
Sent: 10/4/2008  4:29:55 A.M. Pacific Daylight Time
Subj: Cold Gas  Perfusion 
Hello  All, 
After  much effort I retrieved my 1970s photocopy of Pegg's paper wherein 
he fails  to reduplicate Guttman's work. The useful thing about this paper 
and the  Schimmel paper on ultra cold gas perfusion of dog and rat kidneys is 
that they  show what kind of cooling rates are possible and what the range 
of gas flows  through dog kidneys was in Pegg's hands (i.e., a credible, 
solid researcher  whose work is reproducible). 
Schimmel  http://www.ncbi.nlm.nih.gov/pubmed/5872343: 
 
Pegg 
 
I've  attached both papers plus a bit of history from Greg circa 1978 when 
he was very  hot to trot for cold gas cooling . I've also extracted and  
relabeled the cooling curve graph from the Pegg paper. The principal problem  
with Pegg's paper is that the kidneys were in a cold air bath; in fact her 
had  to wrap them in a rubber glove to SLOW the rate of cooling of the cortex. 
 Schimmel et al., cooled their kidneys in an insulated container with the 
only  source of cooling being the intra-arterial helium they used.  
Helium  flow rates through dog kidneys were 750 ml/min = or - 140 ml/min 
and cooling  rate to -80 deg C using gas chilled to -90 deg C was 2.8 deg 
C/min! This is in  close agreement with Schimmel et al's data also copied below. 
 I've marked  up the Pegg data showing very conservative estimates for 
cooling and they come  out where Pegg said they do: it is important to realize 
that the OVERALL rate of  cooling is probably much slower than would be the 
case with a kidney or a  patient loaded with a vitrifiable mixture because: 
1)  There is a huge 'loss' of efficiency in cooling rate in kidneys that 
freeze  because the latent heat of fusion must be dissipated. This is not a 
problem in  systems to be vitrified. 
2)  The delta decay is enormous in Pegg's study because he held his cold 
gas  temperature to no lower than around -80 deg C and kept his delta of  gas 
to organ at around -40 to -50 deg C for the first part of the procedure  
(less later on). If the delta T were TWICE this from the start the cooling rate 
 would be a lot faster. In fact his peak rates were in the range of 4.5 deg 
C min  according to the text in his paper. 
3)  He used helium which as he notes is particularly bad at heat transfer. 
To what  extent this made up by better flow (he reports helium literally 
pouring out of  the uninjured surface of the kidney!!!!! is unknown. However, 
if nitrogen is as  much better you guys say, then cooling rates of ~3 deg 
C/min should be easily  achievable for the kidney and presumably for the brain 
in patients without bad  vascular obstruction. 
If  you eliminate the problem Pegg had with the superficial cortex cooling  
faster than the  deep cortex and medulla by insulating the patient/organ  
from the cold bath gas then you would see a virtual abolition of any 
significant  difference between surface and core cooling - presumably eliminating  
viscoeslastic injury. 
4)  Finally, unlike the case with PFCs the vasculature will be open so that 
 nanomachines or worst case, fixatives, can be introduced later at subzero  
temperatures. It will also be far cheaper than using PFCs if N2 works  OK. 
Mike  Darwin 

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