Summer 1997, Onno Terpstra, the head of our Surgery Department, asked me to explore our options for starting clinical islet isolation and transplantation in our center – the Leiden University Medical Center (LUMC), and prepare a roadmap.
September 1997, at the IPITA congress in Milan (1) , I learned from Camillo Ricordi, the scientific director of the Diabetes Research Institute (DRI) in Miami – where many guest collaborators work – that visiting the DRI some weeks might be a good option to gain sufficient first work experience in his clinical islet transplantation group.
December 1997, with a ‘Roadmap’, I got the green light to start the operationalization of clinical islet transplantation in the LUMC, first with a working visit to Miami to study the state of the art ‘Ricordi’ method of human islet isolation, and then start the human islet isolation work in our Surgery lab in Leiden.
In 1990 I had already gained some initial research experience in our Leiden Islet Laboratory with a small number of isolations of islets from human donor organs, using our innovative method of density gradient purification based on the UW solution (2).
During the first three months of 1998 I worked intensively with my student colleague Josephine Rijkelijkhuizen so that she would be able to continue our xenotransplantation research project as independently as possible in our Surgery research team.
April 1998, after participating in the 1st Workshop on Clinical Islet Transplantation in New Orleans (3) – the ideal introduction – a fruitful working visit to the DRI in Miami followed (4,5), with intensive collaboration with the DRI team on, among other things, six human islet isolations, and also the simultaneously (parallel) conducted research into the purification of the human islets in our Iodixanol gradient in UW-Solution (6).
Here a slideshow illustrating this team up with the DRI team in Miami , working on human islet isolation and purification in the innovative Iodixanol-UWS gradient, April-May 1998.
Notes
1) Innovative Islet Purification in Iodixanol-UWS • IPITA 97 • Michel van der Burg • Miracles.Media • @1MEMO 20250128 • TakeNode • URL michelvanderburg.com/2025/01/28/
2) Percoll UWS Purification Pancreatic Islets • ESOT 1991 Talk • Michel van der Burg • Miracles.Media • @1MEMO 20250114 • URL michelvanderburg.com/2025/01/14/
3) Invited participant 1st Workshop on Clinical Islet Transplantation, New Orleans (LA, USA) April 17–19, 1998
4) 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)
5) DRI Dream Team • Michel van der Burg • Miracles.Media • @1MEMO 20250105 • URL michelvanderburg.com/2025/01/05/
6) Human Islet Purification Miami 1998 • Michel van der Burg • Miracles.Media • 20181102 • URL michelvanderburg.com/2018/11/02/
Citation info : Human Islet Isolation • DRI Miami 1998 • Michel van der Burg • Miracles.Media • @1MEMO 20250204 • TakeNode 86e4a319-a769-44d5-8fa5-de2ca90ab63c • URL michelvanderburg.com/2025/02/04/
Optiprep For Human Islet Purification • Cell Transplant Society 1999 • Michel van der Burg • Miracles.Media • @1MEMO 20250203 • TakeNode bad757b8-674c-4371-938c-ac73287bc457
Poster (#57) presentation Michel van der Burg, Cell Transplant Society congress 1999 in Montreux, Switzerland (1,2)
Outcome of the first series of human islet purifications with the novel Iodixanol -UWS density gradient — developed in the Leiden Islet Laboratory of the LUMC — performed during my 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).
Notes
1) Van der Burg MPM, Ranuncoli A, Molano R, Kirlew T, Ringers J, Bouwman E, Terpstra OT, Ricordi C. Optiprep for human islet purification. 4th International congress of the Cell Transplant Society, Montreux (Switzerland) March 21–24, 1999 .
Citation info : Optiprep For Human Islet Purification • Cell Transplant Society 1999 • Michel van der Burg • Miracles.Media • @1MEMO 20250203 • URL michelvanderburg.com/2025/02/03/
Montage of 100 years diabetes discoveries in educational wall display (created in 1998) from the Joslin Diabetes Center and Roche Diagnostics.
Music : Someday, Maybe by Maya Belsitzman & Matan Ephrat | Artlist
Citation info : Diabetes Discoveries Display • Michel van der Burg • Miracles.Media • @1MEMO 20250117 • TakeNode 00ff4392-ea87-40fb-90a2-ada2cbb77efb • URL michelvanderburg.com/2025/01/17/
Leiden Islet Isolation Chamber • Michel van der Burg • Miracles.Media • @1MEMO 20250116 • TakeNode 398303fe-928a-4c53-839e-9dde0e7d8ec6
Following a working visit February ’92 studying pig islet isolation at the ‘Fondation Transplantation’ in Strasbourg -Hautepierre, France (1) , I designed this islet isolation chamber March 1992 for use in our Leiden Islet Laboratory , together with Gerard Verschagen , head of the precision mechanics workshop of the Laboratory of Physiology of the University Hospital Leiden (AZL , now LUMC), who manufactured this and other of our islet isolation devices.
The chamber was designed with support for use together with the Retsch Vibro Sieving Machine , purchased earlier for our Leiden Islet Laboratory, a vibrating sieving machine I had used in the 70s for isolation cell nuclei (2). The design was based on the Ricordi chamber published 4 years earlier (3).
The drawing was originally designed and produced on a Macintosh computer March 1992, using the MacDraw II application. That Mac file was remastered today in LibreOffice Vanilla, by straightening most of the lines that are slanted after opening in LibreOffice and correcting the font changes. So , not accurate now probably … just for illustration the history of progress in our Leiden Islet Laboratory, and love for art ;)
Notes
1) Xeno Islets • Michel van der Burg • Miracles.Media • @1MEMO 20250113 • URL michelvanderburg.com/2025/01/13/
2) Mennes AM, Bouman H, Van der Burg MPM, Libbenga KR. RNA synthesis in isolated tobacco callus nuclei, and the influence of phytohormones. Plant Sci Lett 1978; 13: 329– 339, ISSN 0304-4211, https://doi.org/10.1016/0304-4211(78)90210-9.
3) Piemonti L, Pileggi A. 25 Years Of The Ricordi Automated Method For Islet Isolation. CellR4 Repair Replace Regen Reprogram. 2013;1(1):e128. PMID: 30505878; PMCID: PMC6267808. URL https://www.cellr4.org/article/128
Citation info : Leiden Islet Isolation Chamber • Michel van der Burg • Miracles.Media • @1MEMO 20250116 • URL michelvanderburg.com/2025/01/16/
Front Page • 20250115_1 • Miracles.Media • Link to full text paper PMID_1465965 🔗
Yesterday, Jan 14th 2025, I posted a video of the slideshow and audio track of my talk on the innovative Percoll-UWS density gradient for the purification of canine and human pancreatic islets, at the 5th Congres European Society for Organ Transplantation, Maastricht (The Netherlands) October 7–10, 1991 (1,2).
That paper was presented the next year , in a poster discussion I co-chaired at the 1st International Congress of the Cell Transplant Society in Pittsburgh (USA) May 31–June 3, 1992 (3,4). The conference proceedings paper of that meeting has been published in Transplantation Proceedings in 1992 (5).
The dutch publisher Elsevier, is publishing Transplantation Proceedings from 1997, and provides (restricted) access to full text online.
Science in print is out of date ?
Previous editions (before 1997) of the journal Transplantation Proceedings , were published by Appleton & Lange, like this 1992 paper (5), and full text is not found online. Also, I am afraid, many libraries have thrown away their stocks of print editions. I, myself, have not kept the bulky Transplantation Proceedings volumes I once bought … thrown away for lack of space , and what I kept is not within reach in practice, piled up in the attic, like the many hundreds of scientific slides…
A pdf copy of that 1992 paper is now available below (5) ;) And copies will be added in upcoming updates of those previous posts.
Notes
1) 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 Congres European Society for Organ Transplantation, Maastricht (The Netherlands) October 7–10, 1991.
2) Percoll UWS Purification Pancreatic Islets • ESOT 1991 Talk • Michel van der Burg • Miracles.Media • @1MEMO 20250114 • URL michelvanderburg.com/2025/10/14/
3) Van der Burg MPM, Guicherit OR, Scherft JP, Bruijn JA, Frölich M, Gooszen HG. Islet preservation during isolation: a new concept in cell transplantation. First International Congress of the Cell Transplant Society, Pittsburgh (USA) May 31 – June 3, 1992.
5) Van der Burg MPM, Guicherit OR, Frölich M, Bruijn JA, Gooszen HG. Islet preservation during isolation: a new concept in cell transplantation. Transplant Proc. 1992 Dec;24(6):2840-1. PMID: 1465965.
Percoll UWS Purification Pancreatic Islets • ESOT 1991 Talk • Michel van der Burg • Miracles.Media • @1MEMO 20250114 • TakeNode 459d71fd-069f-4f6d-9c8f-924ebf132222
Two years, after we introduced the UW-Solution ( UWS ) as the islet isolation solution at the 4th ESOT meeting (1,2) , this talk on the innovative Percoll-UWS density gradient for the purification of canine and human pancreatic islets, was presented at the 5th ESOT — Wednesday Oct 9 , 1991, at 2 PM at the 5th ESOT meeting in Maastricht, Netherlands (3) .
That 5th ESOT meeting was recorded on tape by Audio Archives Int. I purchased some tapes, including the tape of that afternoon session that had started with my talk — and found that the taping of this session had started a few minutes too late … during my talk, the moment I started presenting the Results.
That original tape is now included in this remastered slideshow of my talk presented in this video (20250114) here , starting at 2 min 51 sec. Audio of the first part of my speech , missing in the original 5th ESOT tape, I have recorded this week (from the handout of the speech, written out at full lenght) and added as a voice over at the start of this remastered slideshow.
Cassette Tapes , Audio Archives Int, 5th ESOT • Michel van der Burg • Miracles.Media • @1MEMO 20250114_2 • TakeNode 97730a39-b3db-4f56-a08a-77c4d0406be0
Background
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.
We demonstrated in 1989, that the use of the UW-Solution ( UWS ) for isolation of canine pancreatic islets prior to ‘conventional’ dextran gradient purification, consistently results in a greatly improved purification outcome, of >90% purified islets, and successful transplantation of the canine islets.
Thus , the UWS 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 still being used for preparing density gradients with dextran in our laboratory.
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 UWS (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 UWS…
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 (4).
Thus, designing a new density gradient became urgent January 1990.
Dextran-UWS Gradient • First density gradient in UW-Solution
March 1990 , new density gradient research was started during islet isolation , splitting the suspension of digested pancreatic tissue (‘digest’) for comparison of different density gradients, of either Sigma’s dextran, and Pharmacia’s essentially pure dextran T70 product in Hanks’ solution … and also the first ‘UW gradient’ tested : a dextran gradient in UW-Solution (4).
Percoll-UWS • Successful density gradient in UW-Solution
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, and from May 1990, designing a Pentastarch-UW gradient. Posters on these new density gradients in UWS were presented June 1991 at the 3rd IPITA Congress in Lyon, France (4,5,6).
The paper presented in this 5th ESOT talk, was presented the next year (1992) again in full detail in a poster at the 1st meeting of the Cell Transplant Society in Pittsburgh , and a remastered edition was posted online recently (7).
Proceedings paper below (8).
Slides originally created on a Macintosh computer October 1991, using the MacDraw II application, with graphs from Cricket Graph. Those 1991 files were remastered this month using LibreOffice, as well as the likewise produced Pittsburgh poster for this video of the 5th ESOT talk. Handout speech and report files originally created in the Mac Desk Accessory ‘Acta’, currently accessed by Opal.
Notes
1) Pancreatic Islet Isolation With UW Solution • A New Concept • Michel van der Burg • Miracles.Media • @1MEMO 20241224 • URL michelvanderburg.com/2024/12/24/
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) 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 Congres European Society for Organ Transplantation, Maastricht (The Netherlands) October 7–10, 1991.
4) Dextran UWS Pancreatic Islet Purification • Michel van der Burg • Miracles.Media • @1MEMO 20250104 • URL michelvanderburg.com/2025/01/04/
5) Percoll UWS Pancreatic Islet Purification • 20240731 • Michel van der Burg • michelvanderburg•com
6) PentaStarch UWS Pancreatic Islet Purification • 20240802 • Michel van der Burg • michelvanderburg•com
7) Pittsburgh 1992 Cell Transplant Society • 20240812 • Michel van der Burg • michelvanderburg•com
8) Van der Burg MPM, Guicherit OR, Frölich M, Bruijn JA, Gooszen HG. Islet preservation during isolation: a new concept in cell transplantation. Transplant Proc. 1992 Dec;24(6):2840-1. PMID: 1465965. PDF available below PMID_1465965 🔗
End Card
5th Congres European Society for Organ Transplantation, Maastricht (The Netherlands) October 9, 1991 14:00
0:07 Photo taken at 4th ESOT in Barcelona, 1989 (two years earlier)
0:06-2:51 Voice Over Michel van der Burg • Recorded Jan 11th, 2025 • Substitute for audio missing in original tape recording
2:51 Start Original Audio Tape 5th ESOT session by Audio Archives Int
6:52 Start Discussion • Chair : Reinout van Schilfgaarde (Groningen, Netherlands) • With contributions by Bernhard Hering (Giessen, Germany), R. Seelis (Edmonton, Canada), Derek Gray (Oxford, UK), and Reinout van Schilfgaarde (Groningen, Netherlands).
Citation info : Percoll UWS Purification Pancreatic Islets • ESOT 1991 Talk • Michel van der Burg • Miracles.Media • @1MEMO 20250114 • URL michelvanderburg.com/2025/01/14/
DRI Dream Team • Miami 1998 • Michel van der Burg • Miracles.Media • 20250105_1 • TakeNode e6258505-55a8-4365-bb70-7a1dcd7b5426
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).
Notes
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/
