Slide film of May 11, 1989 developed by Audio Visual Center Leiden University.
Purified islets after using UW solution as the isolation medium, immuno-stained for insulin.
Citation info : Pure Islets • Michel van der Burg • Miracles.Media • @1MEMO 20250111 • URL michelvanderburg.com/2025/01/11/
Poster (1) presented at the 5th Congress European Society for Organ Transplantation, Maastricht (The Netherlands) October 7–10, 1991. The poster was originally created on a Macintosh computer Oct 6, 1991, using the MacDraw II application, with graphs from Cricket Graph. That 1991 poster was remastered today in LibreOffice.
We presented 2 posters at the 5th ESOT, this poster (1), and another one on the effects of denervation with pancreas transplantation (2).
Two years after the 4th ESOT (in Barcelona, Nov 1989) where we introduced the UW-Solution as an islet isolation solution before density gradient purification, we now had a talk at this 5th ESOT on the use of the UW-Solution as the islet isolation solution, both before purification, and also during the purification in an innovative density gradient (3) — the foundation for current clinical purification methods. The talk was recorded on tape (except for the intro), and will be posted here soon too.
1) Van der Burg MPM, Guicherit OR, Ebert R, Jansen JBMJ, Creutzfeld W, Lamers CBHW, Frölich M, Gooszen HG. Postprandial performance after canine islet transplantation: the importance of gut factors. 5th Congress European Society for Organ Transplantation, Maastricht (The Netherlands) October 7–10, 1991.
2) Guicherit OR, Van der Burg MPM, Lemkes HHPJ, Frölich M, Gooszen HG. Pancreatic
denervation causes reduced insulin sensitivity. 5 th Congress European Society for Organ Transplantation, Maastricht (The Netherlands) Oct 7–10 1991.
3) Van der Burg MPM, Guicherit OR, Prins FA, Scherft JP, Frölich M, Gooszen HG. Percoll in UW: efficient iso-osmotic canine and human islet purification. 5th Congress European Society for Organ Transplantation, Maastricht (The Netherlands) October 7–10, 1991.
Citation info : Islet Transplant Performance 5th ESOT 1991 • Michel van der Burg • Miracles.Media • @1MEMO 20250109 • URL michelvanderburg.com/2025/01/09/
Team up with researchers at the Diabetes Research Institute in Miami , working on human islet transplantation (1).
“For National Geographic” announced Camillo Ricordi for fun, that Monday , April 27th in 1998 at the Diabetes Research Institute, when the DRI islet isolation team posed in GMP outfit for this picture (2) — with Elina Linetsky on the left , and me standing second from right — taken after finishing our human islet isolation work, including islet purification in the iodixanol gradient in UW-Solution (3).
1) Working visit April – May 1998 at the “fast track” center of the Diabetes Research Institute (Scientific director Prof. C. Ricordi, MD) of the University of Miami (Miami, FL, USA)
2) Blown up image (from small GIF online in the early DRInet days), taken through a reflecting window.
3) Human Islet Purification Miami 1998 • Michel van der Burg • Miracles.Media • 20181102 • URL michelvanderburg.com/2018/11/02/
Citation info : DRI Dream Team • Michel van der Burg • Miracles.Media • @1MEMO 20250105 • URL michelvanderburg.com/2025/01/05/
Poster (remastered edition, 2025) presented at the 3rd IPITA Congress, June 1991, in Lyon, France (1). One of three posters presented at this congress on purification during the isolation of pancreatic islets (1,2,3,4).
Purification during the isolation of pancreatic islets was greatly improved in 1989 by replacing the conventional islet isolation solutions with the UW organ preservation solution.
The UW-Solution was used as the isolation solution both before , and after the purification of islets — but not yet during the purification step, during centrifugation of the pancreatic tissue in a density gradient.
A conventional (Hanks’ balanced salts) solution was used for preparing density gradients with dextran, the Minneapolis method introduced in 1988 in our laboratory (5).
We had demonstrated previously, that the use of the UW organ preservation solution for isolation of canine pancreatic islets prior to dextran gradient purification, consistently results in >90% purified islets. Further 4 out of 5 islet transplants purified using this gradient had been successful.
Following our islet transplants series June-August 1989 , next a working visit in Minneapolis Sep-Oct ’89, and presentations at the Nov ’89 ESOT congress in Barcelona , we had started a new series of islet isolation experiments from December 1989.
During the first two isolations, Dec 1989, of this new series, I wondered whether the dextran gradient could be optimized , for example by layering the islet suspension in UW-Solution (the pancreatic digest suspension) on top of the dextran bottom layer, or perhaps layering the digest on top of a bottom layer of dextran dissolved in UW-Solution…
The new , much shorter, Labcraft density hydrometers, I had purchased during the Minneapolis visit Nov. 1989 , would greatly facilitate designing new density gradients.
The same lot of dextran (Sigma’s industrial-grade dextran) had been used for all these studies. That stock ran out, so a switch was made Jan 2, 1990 to using a new batch of that dextran powder, resulting however in a significantly impaired recovery of islets during purification , as shown in the poster shown here.
Thus, designing a new density gradient became urgent January 1990.
March 6, 1990 , new density gradient research was started during islet isolation , splitting the suspension of digested pancreatic tissue (‘digest’) for comparison of either dextran of Ficoll (a similar product) in Hanks’ solution , and also a dextran gradient in UW-Solution – the first ‘UW gradient’…
Later that month, purification research was started with a different, essentially pure, dextran product : ‘dextran T70′ from Pharmacia, in Hanks’ solution — with results reported in the poster here.
From April 1990, dextran T70 was used also in dextran-UW gradients, and islet purification research was further extended that month, by designing a density gradient of Percoll in UW Solution (3), and from May 1990, designing a Pentastarch-UW gradient (4).
1) Van der Burg MPM, Guicherit OR, Scherft JP, Frölich M, Gooszen HG. Sigma’s industrial grade dextran is not suitable for islet isolation. 3rd International Congress on Pancreatic and Islet Transplantation, Symposium on Artificial Insulin Delivery System, Lyon (France) June 6–8, 1991.
2) Dextran UWS Pancreatic Islet Purification • 20250104 • Michel van der Burg • michelvanderburg•com
3) Percoll UWS Pancreatic Islet Purification • 20240731 • Michel van der Burg • michelvanderburg•com
4) PentaStarch UWS Pancreatic Islet Purification • 20240802 • Michel van der Burg • michelvanderburg•com
5) Pancreas & Islet Transplantation Program • 20240912 • Michel van der Burg • michelvanderburg•com
Citation info : Dextran UWS Pancreatic Islet Purification • Michel van der Burg • Miracles.Media • @1MEMO 20250104 • URL michelvanderburg.com/2025/01/04/
Slide #19 of talk by Michel van der Burg at the 4th ESOT congress in Barcelona (Spain) Nov 1989 on the paper ‘Pancreatic Islet Isolation With UW Solution • A New Concept’ (1,2). Details of this talk were posted recently (2) with a scan of a paper print of slide #19 – slighly cropped with printing.
Here the full image of the original slide, scanned by Kodak PhotoCD in 1994, with minor color correction added (20250103_1) in this post.
This ‘Slide #19’ shows the final dithizone stained sample of the UW-isolated islets after dextran density gradient purification — a micrograph made April 18, 1989 , the second islet isolation experiment performed using the UW-Solution as the isolation solution.
In the lab journal of the first isolation experiment with UW-Solution, Wednesday April 12th 1989, I noted on the final purified islet preparation : ‘handpicking for encapsulation was not necessary: preparation more than 90% pure ( translated from dutch : “handpicken voor inkapseling was niet nodig: preparaat meer dan 90% zuiver”)’.
‘Handpicking’ of islets had been done at the start of our islet lab in 1985-1987 for counting rodent islets in cell culture dishes, and monitoring islet insulin secretion in tubes (3). Soon, ‘handpicking’ was no longer needed , when monitoring the insulin secretion of isolated islets in perifusion chambers (4,5). However, the handpicking method was used again in a pilot study on encapsulation of islets in 1989 by medical student Joost Clemens (6). Joost had just started on this research project, and was assisting me with islet ‘counting’ (yield and purity assessment) in the ‘duplo’ samples from this first series of UWS isolations.
Macro photography (Photo paper print, September 1987, AVC, Leiden University) of the aspiration of isolated canine pancreatic islets, in a suspension still contaminated with exocrine pancreatic fragments, at the tip of a hand blown glass handpicking pipette (custom made at the Leiden University) collected and transferred into tubes for monitoring insulin secretion the first year of pilot work in the Leiden islet laboratory (4).
1) Pancreatic Islet Isolation With UW Solution • A New Concept • Michel van der Burg • Miracles.Media • @1MEMO 20241224 • URL https://michelvanderburg.com/2024/12/24/pancreatic-islet-isolation-with-uw-solution-a-new-concept-20241224/
2) Pancreatic Islet Isolation in UW Solution & Transplantation • ESOT 1989 Talk • Michel van der Burg • Miracles.Media • @1MEMO 20241229 • URL michelvanderburg.com/2024/12/29/
3) Lucky #1 Islet • 20240811 • Michel van der Burg • michelvanderburg•com
4) Cradle of Islet Transplants • 20240829 • Michel van der Burg • michelvanderburg•com
5) Monitoring pancreatic islets in perifusion • 20240911 | Michel van der Burg | michelvanderburg•com
6) Joost A.M. Clemens (MSc student in Medicine) at the Department of Biomaterials (Prof. dr K. de Groot) and Department of Surgery of the Leiden University (Michel van der Burg , Hein Gooszen). Pilot study of the encapsulation of dog islets using the alginate polylysine and poly-HEMA-phospate method (1989).
At that time , both the Biomaterials department and the Islet Lab of the Surgery department were housed in the building of the Cell Biology department of the Leiden University Hospital (AZL, now LUMC). Below a portrait snapshot I took of Klaas de Groot at a Garden party organized in 1989 by the Department of Cell Biology, Leiden University.
Citation info : Pancreatic Islets UWS Series 1989 • Kodak PhotoCD • Michel van der Burg • Miracles.Media • @1MEMO 20250103 • URL michelvanderburg.com/2025/01/03/
In November 1989, I had my first chance for a presentation at a major international conference, the 4th ESOT meeting in Barcelona, of a paper centered on the rationale for employing the University of Wisconsin (UW) organ preservation solution in pancreatic islet isolation.
This innovative islet isolation work with the UW-Solution had been accepted as a poster presentation for the 4th ESOT meeting (1).
I also took the opportunity to present this new work during a talk on previous isolation work (2,3) at this conference.
‘Behind the scenes’ I had first remade my lost poster at the congress venue (1), and then I rewrote my speech in the hotel room on the older research (2) updated with the more recent work with the UW-Solution, and including the outcome of our first islet transplantations.
Below a scan of that handout of the final speech, written out at full lenght in a notepad from a recent working visit in Minneapolis (4).
Barcelona 89 • Handout 4th ESOT Talk • Michel van der Burg • Miracles.Media • 20241229_3 • TakeNode f8595a82-fba5-4a89-a01f-4c37976d06d7 • PDF FILE 20241229_3 copy is available here
…
( finishing speech first part on our previous islet isolation methods using the conventional RPMI solution – a solution originally designed for tissue culture, not for cold storage of organs )
This slide shows one of the purest preparations obtained, with an estimated purity of 65% islets.
• On the average however a purity of only 30% was obtained.Recently we adopted an entirely new approach to islet isolation.
• Since UW, the new organ cold storage solution has been shown to allow long-term cold storage of the canine pancreas;
• and, since islet isolation too is largely performed in the cold;
• we tested this preservation solution as the isolation medium, throughout the isolation procedure in another 6 dogs;
• as compared to the commonly used solutions like RPMI tissue culture medium.
This slide shows the final dithizone stained preparation after dextran purification of UW-isolated islets.
• UW did not affect islet yield
• however, UW markedly improved purity :
• acinar tissue is virtually absent.
…
1) Pancreatic Islet Isolation With UW Solution • A New Concept • Michel van der Burg • Miracles.Media • @1MEMO 20241224 • URL https://michelvanderburg.com/2024/12/24/pancreatic-islet-isolation-with-uw-solution-a-new-concept-20241224/
2) Van der Burg MPM, Gooszen HG, Field MJ, Scherft JP, Terpstra JL, Van de Woude FT, Guicherit OR, Frölich M, Bruijn JA. Comparison of current islet isolation techniques in dogs. 4th Congress of the European Society for Organ Transplantation, Barcelona (Spain) November 1–4, 1989. Oral presentation. (1)
3) Van der Burg MPM, Gooszen HG, Field MJ, Scherft JP, Terpstra JL, van de Woude FJ, Guicherit OR, Frölich M, Bruijn JA. Comparison of current islet isolation techniques in dogs. Transplant Proc. 1990 Aug;22(4):2044-5. PMID: 1697121.
This paper appears to be not readily available online – a reprint copy is available at this site (1)
4) Working visit Sep – Oct 1989, joining the pancreatic islet isolation team of the pioneer transplant surgeon David Sutherland at the University of Minnesota in Minneapolis.
Citation info : Pancreatic Islet Isolation in UW Solution & Transplantation • ESOT 1989 Talk • Michel van der Burg • Miracles.Media • @1MEMO 20241229 • URL michelvanderburg.com/2024/12/29/
Author Proof Edition • Miracles.Media • 20241228_1 • TakeNode 7118abf6-259c-494c-8445-879afc6d862c
Below the update today added in the 20241224 post : Pancreatic Islet Isolation With UW Solution • A New Concept • Michel van der Burg • Miracles.Media • @1MEMO 20241224 • URL https://michelvanderburg.com/2024/12/24/pancreatic-islet-isolation-with-uw-solution-a-new-concept-20241224/
As reported in our poster and the manuscript delivered in Barcelona of our paper ‘Pancreatic Islet Isolation With UW Solution: A New Concept’ we had been using collagenase in UW solution in this first short (n=4) series of experiments.
Please note, that I changed the description of the collagenase solution to Hanks’ solution (HBBS) when editing the author proof edition shortly before publication of the final paper August 1990 (PMID_2202137 ; 14) — to best convey our current insights and practice.
For hypothetical reasons only — because the UWS was expected to be detrimental perhaps to cell viablity at the higher temperatures during collagenase digestion of the pancreas (the first stage of islet isolation) — I decided to change the collagenase solution in June 1989 when I began a new series of islet isolations for our first canine islet transplants. From that point on, a modified Hanks’ solution was used for collagenase (17).
We did not observe a difference at the time , whether using one or the other solution for collagenase digestion , with respect to either islet purity, recovery, or viability at islet isolation and days later in culture.
Years later , again tor hypothetical reasons , collagenase in UWS was chosen for the isolation of pig islets, in experiments with a long cold ischemia time of the pancreas during transport with distant pancreas procurement from sows in a slaugtherhouse — Ballering (distant family) in Son — near the south border of The Netherlands, with injection of cold collagenase solution before transport, with the aim of better preservation of the islets (18).
Notes
17) Michael P.M. van der Burg. Pancreatic islet transplantation: studies on the technique and efficacy of islet isolation and transplantation. (Doctoral Thesis, Faculty of Medicine, Leiden University Medical Center (LUMC) , Leiden University), Boskoop: M.P.M. van der Burg | Miracles.Media (ISBN electronic, pdf, 9789080216402 ; ISBN print 9789080216419, 9080216410), 1994: 192 p. Leiden University https://catalogue.leidenuniv.nl/permalink/31UKB_LEU/18s393l/alma9940161419602711
18) Van der Burg MPM, Graham JM. Iodixanol density gradient preparation in University of Wisconsin solution for porcine islet purification. ScientificWorldJournal. 2003 Dec 1;3:1154-9. doi: 10.1100/tsw.2003.107. PMID: 14646009; PMCID: PMC5974767.
Citation info : Author Proof Edition • Michel van der Burg • Miracles.Media • @1MEMO 20241228 • URL michelvanderburg.com/2024/12/28/
