Assessment of isolated islet equivalents • Cell Transplant Society 1996 • Michel van der Burg • Miracles.Media • 1MEMO_20251205_1 • Poster 3rd International Congress Cell Transplant Society, Miami (USA) Sep 29 – Oct 2, 1996
Assessment of isolated islet equivalents • Cell Transplant Society 1996 • Michel van der Burg • Miracles.Media • 1MEMO_20251205_1 • Poster 3rd International Congress Cell Transplant Society, Miami (USA) Sep 29 – Oct 2, 1996 • TakeNode 1300e7cd-85a4-4cd0-9cbc-a88746e625ab • #IEQ #diabetes #islets #transplant #methods #CTRMS
IEQ – Islet Equivalent
IEQ islet stands for Islet Equivalent, a standard unit used to measure the total volume of islets (clusters of insulin cells and other hormone-producing cells in the pancreas). It is defined as a single spherical islet with a diameter of 150 µm. The IEQ is a crucial parameter for assessing the quantity of islets for procedures like clinical islet transplantation, which is a treatment for type 1 diabetes.
Modified international procedure
Following a consensus report in 1989 – 1990 by Ricordi et al (1a, 1b) on islet isolation assessment, the total volume of isolated islets is generally expressed in the number of islet equivalents (IEQs) — defined as islets of 150 µm diameter— and many centers use the advocated now classic international procedure (CIP) of sizing all islets in classes with 50-µm increments (i.e., 50–100, 100–150, etc.) for calculation of the number of IEQs. For each class the number of IEQs are calculated by multiplying the islet counts with a conversion factor — based on the mean volume of that class.
A modified international procedure — based on our conventional Leiden procedure (2,3) with islet sizing in classes with 25-µm increments — is suggested for accurate assessment of the IEQs especially when isolation yields mostly smaller islets, in our paper ‘Assessment of isolated islet equivalents’ presented at the 3rd International Congress Cell Transplant Society, Miami (USA) Sep 29 – Oct 2, 1996, in both a poster (4) , and proceedings paper (5). A photo of the original poster , (retrieved somewhat wrinkled 30 years later from my archive), is posted here, as well as a pdf from the (corrected proof) manuscript of the proceedings paper below (6).
The Cell Transplant Society was founded in 1991, and has been renamed the Cell Transplant and Regenerative Medicine Society (CTRMS).
Notes
1a. Ricordi C, Gray DW, Hering BJ, Kaufman DB, Warnock GL, Kneteman NM, Lake SP, London NJ, Socci C, Alejandro R, et al. Islet isolation assessment in man and large animals. Acta Diabetol Lat. 1990 Jul-Sep;27(3):185-95. doi: 10.1007/BF02581331. PMID: 2075782.
1b. Quantitative And Qualitative Standards For Islet Isolation Assessment In Man And Large Mammals. International Workshop during the 2nd Congress on Pancreas and Islet Transplantation (1989). Camillo Ricordi. Archive Michel van der Burg • Miracles•Media • 1MEMO_20251206_07 . Available from Dec 6, 2025 URL https://michelvanderburg.com/2025/12/06/
2. Van der Burg MPM, Guicherit OR, Frölich M, Scherft JP, Prins FA, Bruijn JA, Gooszen HG. Assessment of islet isolation efficacy in dogs. Cell Transplant. 1994 Jan-Feb;3(1):91-101. doi: 10.1177/096368979400300113. PMID: 8162296.
3. Paper (Notes 2) included as Chapter 3 in my doctoral thesis (Leiden University, November 1994) : Assessment of islet isolation efficacy in dogs. In : Van der Burg MPM. Pancreatic islet transplantation: studies on the technique and efficacy of islet isolation and transplantation ( Chapter 3). (Doctoral Thesis, Leiden University, 1994), Paperback (1994, Nov 9) Boskoop: Van der Burg (ISBN 9080216410); E-book (2022, Oct 25) Boskoop: Michel van der Burg | Miracles•Media ( ISBN 9789080216402). Retrieved (Nov 24th, 2025) from Leiden University Scholarly Publications, Persistent URL https://hdl.handle.net/1887/3486604 . Direct link to file Chapter 3 , URL https://scholarlypublications.universiteitleiden.nl/access/item%3A3486610/view
4. Van der Burg MPM, Scheringa M, Basir I, Bouwman E. Assessment of isolated islet equivalents. Poster presented at the Third Int. Congress Cell Transplant Soc., Miami (USA) Sept. 29 – Oct. 2, 1996. In : Assessment of isolated islet equivalents • Cell Transplant Society 1996 • Michel van der Burg • Miracles.Media • @1MEMO 20251205 • URL https://michelvanderburg.com/2025/12/05 • File 1MEMO_20251205_1 • TakeNode 1300e7cd-85a4-4cd0-9cbc-a88746e625ab
5. Van der Burg MPM, Scheringa M, Basir I, Bouwman E. Assessment of isolated islet equivalents. Transplant Proc. 1997 Jun;29(4):1971-1973. doi: 10.1016/s0041-1345(97)00188-7. PMID: 9193483.
6. Manuscript (corrected proof for Transplant Proc paper PMID: 9193483). Van der Burg MPM, Scheringa M, Basir I, Bouwman E. Assessment of isolated islet equivalents • 1MEMO_20251205_2 • TakeNode 48380f3c-b3f7-416e-90bb-ad6c53129e46 • PDF available below , File 1MEMO_20251205_2
Citation info : Assessment of isolated islet equivalents • Cell Transplant Society 1996 • Michel van der Burg • Miracles.Media • @1MEMO 20251205 • TakeNode 1300e7cd-85a4-4cd0-9cbc-a88746e625ab / 48380f3c-b3f7-416e-90bb-ad6c53129e46 • URL https://michelvanderburg.com/2025/12/05
Manuscripts (Preprints) and Abstracts copies of the presentations at the IPITA 1997 meeting in Milan (Italy).
1) Van der Burg MPM, Basir I, Zwaan RP, Bouwman E. Porcine islet preservation during isolation in University of Wisconsin solution. Transplant Proc. 1998 Mar;30(2):360-1. doi: 10.1016/s0041-1345(97)01307-9. PMID: 9532079.
PMID_9532079_20250205_1 • Michel van der Burg • Miracles.Media • @1MEMO 20250205_1 • CC BY-NC-ND • TakeNode 406dbe1e-66e3-4edc-acb8-83fdc8ddc5c8
2) Van der Burg MPM, Basir I, Bouwman E. No porcine islet loss during density gradient purification in a novel iodixanol in University of Wisconsin solution. Transplant Proc. 1998 Mar;30(2):362-3. doi: 10.1016/s0041-1345(97)01308-0. PMID: 9532080.
PMID_9532080_20250205_2 • Michel van der Burg • Miracles.Media • @1MEMO 20250205_2 • CC BY-NC-ND • TakeNode c60e0743-946a-4950-b156-7e671593e482
Van der Burg MPM, Basir I, Bouwman E. No porcine islet loss during density gradient purification in a novel iodixanol in University of Wisconsin solution (Abstract). Acta Diabetol 1997; 34: 101.
Van der Burg MPM, Basir I, Zwaan RP, Bouwman E. Porcine islet preservation during isolation in University of Wisconsin solution (Abstract). Acta Diabetol 1997; 34: 136.
1MEMO_ 20250205_3 • Michel van der Burg • Miracles.Media • @1MEMO 20250205_3 • CC BY-NC-ND • TakeNode e5b1c598-fc48-4f2a-93ae-526cd4be082e
Islets isolated April 18, 1989 using the UW-Solution • Miracles.Media • 20250103_1 • TakeNode eeb55729-c02b-4f73-ab0e-9f71b65bf85e
Rightaway, April 1989, when we obtained these highly purified canine islets of Langerhans by introducing the UW-Solution for isolating the islets from pancreases (1,2,3), we started using these islets to study the importance of gut factors for islet transplants — the capacity of the isolated islets to secrete insulin during stimulation with glucose, other nutrients, and potentially gut hormones ( ‘incretins’).
Isolated islets in perifusion chambers
Isolated islets, not transplanted, were examined in the Leiden Islet Laboratory. The insulin secretion of these islets was measured, while the islets were housed in plastic micro-chambers , that were flushed with solutions containing various levels of glucose and gut hormones , mimicking the blood levels as found following meals in islet transplants (4).
Monitoring pancreatic islets in perifusion • Michel van der Burg • Miracles.Media • @1MEMO 20240911
Autotransplantation of islets
A few months later , Summer 1989, we performed a series of transplants of isolated canine islets (5) , we likewise focussed our research on the importance of gut factors in metabolic control by the islet grafts, and therefore introduced meal tests — apart from a series of intravenous tests. Both simple and convenient, such meal tests proofed to be also an excellent way to study both the capacity of the transplanted islets to secrete insulin, as well as the contribution of gut hormones – in the so-called ‘entero-insular axis’ (6).
Autotransplantation of islets in the spleen • Michel van der Burg • Miracles.Media • @1MEMO 20250125_1 • Left : Canine pancreas with two cannulas in the pancreatic ducts (for infusion of collagenase solution) , with the blood vessels clamped at the time of removal of the gland. Not shown here: After removal of the gland the collagenase solution is infused , and the pancreatic islets are isolated within a few hours. Right : Next the purified islets are returned by infusion in the spleen of the same animal (auto-transplantation). Drawings by medical artist J. Wetselaar-Whittaker — with my hand posing for the injection drawing ;)
Contribution of gut factors to canine isolated islet function ?
Spring 1990 our first results could be presented of these sophisticated islet function tests upto 3 months after islet transplantation, together with our first findings of the direct effects of the gut hormones CCK and GIP on the isolated islets in the perifusion system in the Leiden Islet Lab.
Spring meeting 1990 of the Dutch Society for Gastroenterology, Veldhoven, Netherlands • Michel van der Burg • Miracles.Media • @1MEMO 20250125_2
Here the proceedings presented at the 1990 spring meeting of the Dutch Society for Gastroenterology (7).
Dutch Islets Transplant Team
October 8, 1990, Paul van Suylichem, from the Groningen islet research group, visited his alma mater again, the Leiden University on the occasion of the 3rd Symposium Experimental Surgical Research (SEOHS). I was presenting results at the symposium on metabolic control upto 3 mo after the succesful canine islet transplants – islets isolated using the UW-Solution – known as Viaspan for the cold storage of donor organs (8,9). Paul had started together with me in 1985 building the Leiden Islet Lab (10), that I continued from 1986 after Paul left together with project leader Reinout van Schilfgaarde starting the Groningen islet group (11). I took the chance to invite Paul for a visit together that day in the nearby Leiden Islet Lab , for a closer look at our latest work on canine islet isolation, transplantation, and the new Percoll-UWS purification gradients (12) — and took this picture of Paul examining an islet prep at the microscope in the lab , with the Acusyst perifusion system in the background. In late 1990, the Groningen islet team with Paul would also start this preclinical model of canine islet isolation and transplantation.
Paul van Suylichem (Groningen Islet Team) in Leiden Islet Laboratory, October 8, 1990 • Photo by Michel van der Burg • Miracles.Media • @1MEMO 20250125_3
A year later, Oct 1991, during the 5th Congress of the European Society for Organ Transplantation Congress (5th ESOT) in Maastricht (12), I learned from Paul’s co-worker Jan-Erik van Deijnen that the Groningen team, after initially several failed transplant attempts, had finally succeeded in the last 5 transplants in a row. They had mastered the technique and had started to complete this work with histology of the transplants.
We, in Leiden, had made plans earlier that summer to expand our small group of islet transplants, with a second series of transplants with a view to expanding our research on metabolic control in islet transplantation, with new sophisticated research on the effect on insulin secretion of the newly discovered gut hormone GLP-1. At the same time we would also be able to test our efficient new technique of isolation and purification of the islets in that transplantation setting.
A few days after this 5th ESOT congress it seemed better to me to refrain from new transplants in more animals, and I proposed to expand our sophisticated, functional research with research on the Groningen canine islet transplants.
Later that month, Oct 1991, islet perifusion experiments with the gut hormone GLP-1 were started (13,14,15).
And… November 1991, Paul van Suylichem’s research associate Annemiek Weemaes brought the Groningen canine transplants to Leiden, for our very successful collaborative project , with the planned additional studies in the combined Leiden and Groningen group of transplants, examining additionally insulin action (sensitivity) and the ‘incretin’ effect (stimulation of insulin secretion) of the gut hormone GLP-1. Experiments we completed in 1992 (14,16,17,18).
Notes
IMAGE 20250103_1 Islets isolated April 18, 1989 using the UW-Solution • Miracles.Media • 20250103_1 • TakeNode eeb55729-c02b-4f73-ab0e-9f71b65bf85e
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) Pancreatic Islets UWS Series 1989 • Kodak PhotoCD • Michel van der Burg • Miracles.Media • @1MEMO 20250103 • URL michelvanderburg.com/2025/01/03/
4) Monitoring pancreatic islets in perifusion • Michel van der Burg • Miracles.Media • @1MEMO 20240911 • TakeNode fdf6f65c-28b7-4936-8c23-83225e6f2ff0 • URL https://michelvanderburg.com/2024/09/11/
IMAGE 20240911 Monitoring pancreatic islets in perifusion • Michel van der Burg • Miracles.Media • @1MEMO 20240911 • TakeNode fdf6f65c-28b7-4936-8c23-83225e6f2ff0
5) Islet Transplantation Breakthrough in Leiden University Hospital • 20240830 • Michel van der Burg • michelvanderburg•com • URL https://michelvanderburg.com/2024/08/30/
6) Entero Insular Axis • Michel van der Burg • Miracles.Media • @1MEMO 20250123 • URL michelvanderburg.com/2025/01/23/
IMAGE 20250125_1 Autotransplantation of islets in the spleen • Michel van der Burg • Miracles.Media • @1MEMO 20250125_1 • Left : Canine pancreas with two cannulas in the pancreatic ducts (for infusion of collagenase solution) , with the blood vessels clamped at the time of removal of the gland. Not shown here : After removal of the gland the collagenase solution is infused , and the pancreatic islets are isolated within a few hours. Right : Next the purified islets are returned by infusion in the spleen of the same animal (auto-transplantation). Drawings by medical artist J. Wetselaar-Whittaker — with my hand posing for the injection drawing ;) • TakeNode da74e6a2-e21d-4690-afe5-356949221658
IMAGE 20250125_2 Spring meeting 1990 of the Dutch Society for Gastroenterology, Veldhoven, Netherlands • Michel van der Burg • Miracles.Media • @1MEMO 20250125_2 • TakeNode 65cb9de6-a111-4636-8766-d586b001d73e
7) Van der Burg MPM, Guicherit OR, Jansen JBMJ, Lamers CBHW, Scherft JP, Gooszen HG. Contribution of gut factors to canine isolated islet function? Spring meeting of the Dutch Society for Gastroenterology (NVGE), Veldhoven (The Netherlands) March 23–24, 1990. The proceedings pdf (1MEMO_20250125_2) is available for download below.
Five years later the Dutch Society for Gastroenterology awarded the Glaxo Wellcome Gastrointestinal Research Award for this research (Ph.D. thesis “Pancreatic islet transplantation”) at the Fall meeting of the Dutch Society for Gastroenterology (NVGE), Veldhoven, The Netherlands, October 5, 1995).
Glaxo Wellcome Gastroenterology Research Award, Oct 5, 1995, Dutch Society for Gastroenterology, Veldhoven, Netherlands • Michel van der Burg • Miracles.Media • @1MEMO 20250125_4 • TakeNode 3152bca6-c98e-4900-89bf-d3e241f14405
8) Van der Burg MPM, Guicherit OR, Ploeg RJ, Scherft JP, Bruijn JA, Frölich M, Prins FA, Gooszen HG. Successful canine pancreatic islet transplantation using ViaSpan. 3rd Symposium Experimental Surgical Research (SEOHS), Leiden (The Netherlands) October 8, 1990.
9) Van der Burg MPM, Gooszen HG, Ploeg RJ, Guicherit OR, Scherft JP, Terpstra JL, Frölich M. Over 90% purified canine isolated pancreatic islets using UW solution (Abstract). Neth J Surg 1990; 42: 30. Pdf abstract (1MEMO_20250125_5) is available for download below.
12) Percoll UWS Purification Pancreatic Islets • ESOT 1991 Talk • Michel van der Burg • Miracles.Media • @1MEMO 20250114 • URL michelvanderburg.com/2025/01/14/
IMAGE 20250125_3 Paul van Suylichem (Groningen Islet Team) in Leiden Islet Laboratory, October 8, 1990 • Photo by Michel van der Burg • Miracles.Media • @1MEMO 20250125_3 • TakeNode e8ce7630-4e75-402b-a4c2-9b007a8dd61b
13) Van der Burg MPM, Guicherit OR, Scherft JP, Frölich M, Terpstra JL, Gooszen HG. Functie na intralienale transplantatie van eilandjes van Langerhans in de hond ( Function after intrasplenic transplantation of islets of Langerhans in dogs ). Surgeon days ’92 of the Dutch Surgery Society, Rotterdam (The Netherlands) May 21–22, 1992. In : Gut factors controlling pancreatic islets • 20240910 | Michel van der Burg | michelvanderburg•com
14) 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. URL Thesis Repository Leiden University https://hdl.handle.net/1887/3486604
15) van der Burg MPM, Guicherit OR, Frölich M, Gooszen HG. Insulinotropic effects of cholecystokinin, gastric inhibitory polypeptide and glucagon-like peptide-1 during perifusion of short-term cultured canine isolated islets. Regul Pept. 1995 Dec 7;60(1):61-7. doi: 10.1016/0167-0115(95)00122-4. PMID: 8747785.
16) Van der Burg MPM, Van Suylichem PTR, Guicherit OR, Frölich M, Lemkes HHPJ, Gooszen HG. Glycemic control mechanisms after canine islet autografting. 5th International Congress on Pancreas and Islet Transplantation (IPITA), Miami Beach (USA) June 18–22, 1995.
17) van der Burg MPM, van Suylichem PTR, Guicherit OR, Frölich M, Lemkes HHPJ, Gooszen HG. Glycemic control mechanisms after canine islet autografting. Transplant Proc. 1995 Dec;27(6):3187-8. PMID: 8539903. Download (PMID_8539903) below .
18) van der Burg MPM, van Suylichem PTR, Guicherit OR, Frölich M, Lemkes HHPJ, Gooszen HG. Glucoregulation after canine islet transplantation: contribution of insulin secretory capacity, insulin action, and the entero-insular axis. Cell Transplant. 1997 Sep-Oct;6(5):497-503. doi: 10.1177/096368979700600509. PMID: 9331501. Download Free PDF https://hdl.handle.net/11370/59231eab-6091-415d-8b2b-4e5e6508a978
Citation info : Dutch Islet Transplants Team • Michel van der Burg • Miracles.Media • @1MEMO 20250125 • URL michelvanderburg.com/2025/01/25/
Congress of The Transplantation Society, Lobby of the Fairmont Hotel, San Francisco, California, USA, August 1990 • Michel van der Burg • Miracles.Media • @1MEMO 20250118_1 • TakeNode 4af71bca-edaa-4adb-9dce-556534844f5b
Following papers presented in 1989 demonstrating that over 90% pure islets are isolated from pancreases when using the UW organ preservation solution (1), the outcome of transplantation of highly purified UW-isolated islets was reported in a proceedings paper presented August 1990 at the XIII International Congress of The Transplantation Society in San Francisco, USA (2,3). The Transplantation Proceedings paper, published Feb 1991 is now available online below (3).
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) Van der Burg MPM, Guicherit OR, Ploeg RJ, Frölich M, Bruijn JA, Scherft JP, Gooszen HG. Metabolic control after autotransplantation of highly purified canine pancreatic islets isolated in UW-solution. XIII International Congress of The Transplantation Society, San Francisco (USA) August 19–24, 1990.
3) van der Burg MPM, Guicherit OR, Ploeg RJ, Frölich M, Bruijn JA, Scherft JP, Gooszen HG. Metabolic control after autotransplantation of highly purified canine pancreatic islets isolated in UW solution. Transplant Proc. 1991 Feb;23(1 Pt 1):785-6. PMID: 1990691. PDF available below
Citation info : Transplants of UW-Isolated Islets • Transplantation Society 1990 Paper • Michel van der Burg • Miracles.Media • @1MEMO 20250118 • URL michelvanderburg.com/2025/01/18/
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.
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/
Pancreatic Islet Isolation With UW Solution • A New Concept • 20241224
Michel van der Burg • 20241224 • Last update 20241228-1614
In November 1989 in Barcelona, I had my first opportunity to present a paper at a major international organ transplantation meeting — the 4th ESOT — focusing on the rationale for using the UW organ preservation solution during pancreatic islet isolation.
Poster lost
Excited about giving a talk and poster presentation at this 4th ESOT congress in Barcelona, I forgot to take my poster from the overhead compartment of the plane upon arrival in Barcelona. A new poster was made on the spot at the Sandoz booth in the congress venue, by cut and paste work using the manuscript of the congress proceedings paper (PMID 2202137) and enlargement with a Sandoz A3 photocopier. Due to design constraints, the author affiliation info was omitted, and the Du Pont logo was added (image 20241025_1).
Scan of the slide picture taken at the 4th Congress of the European Society for Organ Transplantation, Barcelona (Spain) November 1–4, 1989 • Michel van der Burg • Miracles.Media • 20241025_1 • TakeNode 054301b6-0b6e-458c-84f6-0b76e25092d5
Barcelona ’89 poster remastered
That photo of the poster board in Barcelona (20241025_1) was used for creating this digitally remastered poster presented here (20241025_2) — which now includes the complete manuscript, as well as the Du Pont logo ;)
Poster 4th Congress of the European Society for Organ Transplantation, Barcelona (Spain) November 1–4, 1989 • Digitally remastered from original manuscript of article PMID 2202137 by author, publisher, M.P.M. van der Burg • Miracles.Media • 20241025_2 • TakeNode 124e20db-758a-4bdb-b854-c6cefdb7cc3c
The Nov ’89 Barcelona publications, were the first ones dedicated to presenting the concept , the rationale, for using the UW organ preservation solution during pancreatic islet isolation.
Venue 4th Congress of the European Society for Organ Transplantation, Barcelona (Spain) November 1–4, 1989 • Michel van der Burg • Miracles.Media • 20241224 • TakeNode 103c4c3c-5d36-4111-a5f8-f60e81c5db4d
This wasn’t the first time we reported the news of our results with this new, innovative, method developed in our pre-clinical model for the isolation and purification of pancreatic islets of Langerhans for transplantation in diabetic patients. Below that background, publications, and papers available for download.
Background
I was well aware of the development in the late 80s by Belzer’s team at the University of Wisconsin in Madison (USA) of the new solution to preserve pancreas donor organs during cold storage for transplantation :
In 1986 the Belzer team had reported on the newly developed cold storage solution for pancreas preservation, the University of Wisconsin (UW) Solution (1).
From 1986 our colleague Rutger Ploeg (from the Department of Surgery of Leiden University) had been doing PhD research in Belzer’s organ preservation laboratory in Madison. He introduced the ‘…new cold storage solution, the “UW-Solution” in a letter Dec. 10th, 1987 to all Eurotransplant centres (2), and I had assisted during Rutger Ploeg’s preservation research in Madison on the UW solution in pancreas transplantation in dogs, by calculating the k-values of glucose tolerance (3,4).
1) Wahlberg JA, Southard JH, Belzer FO. Development of a cold storage solution for pancreas preservation. Cryobiology. 1986;23(6):477–482.
2) Alexandre G, Margreiter R, Persijn GG, Pichlmayr R, Terpstra JL, Ploeg RJ. To all Eurotransplant centres : Introduction new cold storage solution, the “UW-Solution”. Letter Dec 10, 1987 , Ploeg RJ, Department of Surgery, University Hospital Leiden (AZL , now LUMC).
3) Ploeg RJ, Goossens D, Sollinger HW, Southard JH, Belzer FO. Efficacy of 48-hour pancreas preservation with UW solution in the dog allograft model. Transplant Proc. 1988 Oct;20(5):1026-8. PMID: 3055478.
4) Ploeg RJ. Preservation of kidney and pancreas with the UW solution : experimental and clinical studies. (Thesis, Leiden University), ‘s-Gravenhage : Pasmans (ISBN 9090042490), 1991: 231 p. URL https://search.worldcat.org/en/title/65672513
First thought
In early 1989, I wondered how our research, into improving the technique of pancreatic islet isolation, could benefit from the great interest in this new organ preservation solution, and the contacts through Ploeg with both the Belzer laboratory and Du Pont (Du Pont Critical Care, Waukegan, USA), the manufacturer of the commercial UW Solution.
Radical choice
The most logical , traditional, choice would be, to investigate organ preservation of the pancreas prior to pancreatic islet isolation. However, logistically, this seemed to be too much of a change in our research. Therefore, in February 1989, I made the radical choice of testing the UW Solution as a replacement for conventional isolation solutions in our preclinical transplantation model of canine islet isolation.
Start
A research plan was drawn up for Du Pont (Robert Carter, Clinical Research Project Coordinator, DuPont, UK), and we started our work March 1989. At first — the first two islet isolation experiments — the UW Solution was only used at the first stage of the isolation procedure, as the collagenase solution for pancreatic injection, transport, and digestion in the laboratory. From April 1989 on, the UW-Solution was used in all our isolation steps, both before density gradient purification, and also for washing the purified islets.
Rationale
The research started in April 1989 with the rationale , that : because the UW-Solution (UWS) protects the viability of the pancreas during cold storage, the UWS can also improve the yield of viable isolated islets, because islet isolation also takes place mainly at low temperature.
Discovery
However, from the first time in April 1989 that the UW-Solution was used during all isolation steps, the tissue immediately appeared different, with almost complete islet purification due to a clear difference in islet density and the darker and more compact looking exocrine pancreatic tissue, compared to the previous conventional isolations.
I did not expect this… but I understood it immediately, even during that first isolation: the effect of UWS during the isolation, the effect on the density, by counteracting cell swelling of especially the other, exocrine, pancreatic tissue, resulting in that tremendous improvement in the purification of islets.
News
The news of the exciting finding of over 90% purity of these UWS-isolated islets was brought first that month, April 1989, during my oral presentation (5) at the General Surgery Science Days, the yearly meeting on the current scientific research taking place at the Department of Surgery of the Leiden University Hospital (now LUMC) in Leiden , Holland .
5) Van der Burg MPM. New methods of islet isolation – a comparative study (dutch : ‘Nieuwe methoden van eilandisolatie – een vergelijkend onderzoek). General Surgery Science Days 1989, Leiden University Hospital (dutch : Wetenschapsdagen Algemene Heelkunde 1989, AZL), Leiden, (The Netherlands) April 28, 1989. Yearly meeting on current research at the Department of Surgery of the Leiden University Hospital (now LUMC) in Leiden , Holland .
Next, a manuscript was submitted June or July 1989 for publication of a Letter in The Lancet (6)… but was rejected.
6) Van der Burg MPM, Gooszen HG, Ploeg RJ, Guicherit OR, Scherft JP, Terpstra JL, Bruijn JA, Frölich M. Pancreatic islet isolation with UW solution: a new concept. Manuscript submitted June/July 1989 for publication as Letter in The Lancet. (rejected). Report online in : Lancet Letter 1989 UW Solution Islet Isolation | 20220823 | Michel van der Burg | michelvanderburg•com
Islet transplantation
Internationally , the news of both our first pre-clinical islet transpant, and the islet purification success when using UWS during islet isolation, was first reported July 8, 1989 at the Anglo Danish Dutch Diabetes Group meeting in Oxford, UK (7). National news reports appeared first September ’89 in the Cicero magazine (8) , and Oct ’89 in the Dutch newspaper Leidsch Dagblad (9).
7). Van der Burg MPM, Gooszen HG, Scherft JP, Terpstra JL, Frölich M, Guicherit OR, Lemkes HHPJ, Bruijn JA. The isolation of canine pancreatic islets for transplantation. Seventh Annual Meeting Anglo Danish Dutch Diabetes Group, Oxford (UK) July 5–9, 1989. Report online in : ADD Diabetes Group 1989, St Edmund Hall, Oxford • Michel van der Burg • Miracles•Media • 20241019 • michelvanderburg•com
8), ‘Eilandjes’ getransplanteerd | by Sylvia van Leeuwen in Cicero, Sep. 15th, 1989 (ISSN 0920-2900), the biweekly publication of the Academic Hospital and Leiden Medical Faculty | 20240830_3 • michelvanderburg•com Report online : Islet Transplantation Breakthrough in Leiden University Hospital • 20240830 • Michel van der Burg • michelvanderburg•com
9). Doorbraak in onderzoek naar behandeling suikerpatiënten. Ontdekking door artsen Leids Academisch Ziekenhuis. (EN tr. “Breakthrough in research into treatment of diabetics. Discovery by doctors of Leiden University Hospital”) | by Gert Visser, in Leidsch Dagblad, Oct 24, 1989 | Dutch newspaper. Report online : Islet Transplantation Breakthrough in Leiden University Hospital • 20240830 • Michel van der Burg • michelvanderburg•com
Internationally at a major meeting, the UWS news was first presented in a poster presentation September 1989 in Minneapolis (10). The UWS data had been added ad hoc in the poster – that is , it wasn’t part of the accepted abstract. The first proceedings paper on our UWS work was also submitted at that meeting , and was published April ’90 (11).
10). Van der Burg MPM, Gooszen HG, Ploeg RJ, Scherft JP, Field MJ, Guicherit OR, Terpstra JL, Van de Woude FT, Frölich M, Bruijn JA. Comparison of islet isolation techniques in dogs: Over 90% purified islets using UW solution. 4th International Symposium on Organ Procurement and Preservation and 2nd International Congress on Pancreatic and Islet Transplantation, Minneapolis (USA) September 17–22, 1989 Report online in : Minneapolis 1989 Poster | 20240804 | Michel van der Burg | michelvanderburg•com
11). Van der Burg MPM, Gooszen HG, Ploeg RJ, Scherft JP, Field MJ, Guicherit OR, Terpstra JL, Van de Woude FJ, Frölich M, Bruijn JA. Comparison of islet isolation techniques in dogs: Over 90% purified islets using UW solution. Transplant Proc. 1990 Apr;22(2):795-6. PMID: 2158174. This paper appears to be not readily available online – a reprint copy is available here PMID_2158174 🔗
A new concept – Nov 1989 , Barcelona, Spain – 4th ESOT
Finally , November 1989 in Barcelona, Spain – at the 4th ESOT meeting – the first presentations followed, focussing on the concept — the rationale — for using the UW organ preservation solution during pancreatic islet isolation — in the book of abstracts (12), the poster shown above (13) that was created from the proceedings paper submitted at this meeting (14), and , I included this UWS work also ad hoc in the talk delivered at this meeting on comparison of islet isolation techniques (12, 15, 16). I plan to post on that talk soon.
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 , 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).
12) Excerpt from book of abstracts 4th Congress of the European Society for Organ Transplantation, Barcelona (Spain) November 1–4, 1989 , including the abstracts : – Van der Burg MPM, Gooszen HG, Guicherit OR, Ploeg RJ, Scherft JP, Terpstra JL, Bruijn JA, Frölich M. UW solution as the isolation medium markedly improves canine islet isolation (abstract). – 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 (abstract). Excerpt ESOT abstracts book available here 19891101_ESOT 🔗
13) Van der Burg MPM, Gooszen HG, Ploeg RJ, Guicherit OR, Scherft JP, Terpstra JL, Bruijn JA, Frölich M. Pancreatic islet isolation with UW solution: a new concept. 4th Congress of the European Society for Organ Transplantation, Barcelona (Spain) November 1–4, 1989. Poster presentation. Report online (here) : Pancreatic Islet Isolation With UW Solution – A New Concept • 20241224 • Michel van der Burg • michelvanderburg•com PDF poster — M.P.M. van der Burg • Miracles.Media • 20241025_2 • TakeNode 661fade9-51a7-42b1-a7e1-1e281f74ad6d — available here 20241025_2 🔗
14) Van der Burg MPM, Gooszen HG, Ploeg RJ, Guicherit OR, Scherft JP, Terpstra JL, Bruijn JA, Frölich M. Pancreatic islet isolation with UW solution: a new concept. Transplant Proc. 1990 Aug;22(4):2050-1. PMID: 2202137. This paper appears to be not readily available online – a reprint copy is available here PMID_2202137 🔗
15) 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.
16) 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 here PMID_1697121 🔗
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.
*Audio of data discussion posted in : Percoll UWS Purification Pancreatic Islets • ESOT 1991 Talk • Michel van der Burg • Miracles.Media • @1MEMO 20250114 • URL michelvanderburg.com/2025/01/14/
Updates
20241227-1329 Better copy of Minneapolis proceedings paper replaces PMID_2158174
20241228-1614 Author Proof section on the collagenase solution changes
*20250124-0244 Added reference to audio of data discussion posted in : Percoll UWS Purification Pancreatic Islets • ESOT 1991 Talk • Michel van der Burg • Miracles.Media • @1MEMO 20250114 • URL michelvanderburg.com/2025/01/14/
Citation info : Pancreatic Islet Isolation With UW Solution • A New Concept • Michel van der Burg • Miracles.Media • @1MEMO 20241224 • URL michelvanderburg.com/2024/12/24/