7th IPITA World Congress 1999 • 1MEMO_20260325_1 • Michel van der Burg • Miracles•Media • TakeNode 770715b8-ca68-4c00-8a24-24fe0d216c10
Poster presentation (#P298) Michel van der Burg, 7th World Congress of the International Pancreas & Islet Transplant Association, Sydney (Australia) August 22–25, 1999 (1).
Outcome of the first series of human islet purifications with the novel Iodixanol -UWS density gradient — developed originally in the difficult model of pig islet isolation in our Leiden Islet Laboratory of the LUMC (2) — and, performed in 1998 during my working visit at the “fast track” center of the Diabetes Research Institute (Scientific director Prof. C. Ricordi, MD) of the University of Miami , in Miami, Florida, USA .
Notes
1) Van der Burg MPM, Ranuncoli A, Molano R, Kirlew T, Ringers J, Bouwman E, Terpstra OT, Ricordi C. New powerful tool for human islet purification: OptiPrep-UWS? 7th World Congress of the International Pancreas & Islet Transplant Association, Sydney (Australia) August 22–25, 1999. Abstract in Programme and Abstract Book, page 169, P298 .
Abstracts of previous IPITA meetings had been published in print in scientific journals (2), however, at the turn of the millennium in 1999, with the rise of the internet , the 7th IPITA congress abstracts were published online only at the official website of the IPITA, in Oxford at the time (www.jr2.ox.ac.uk/ipita), and cannot be retrieved now (3). I kept an archive with photocopies of our abstracts published in print in the Abstract Book of the 7th IPITA. Below that abstract of poster presentation P298 at page 169 in the Programme and Abstract Book.
7th IPITA World Congress 1999 • 1MEMO_20260325_2 • Michel van der Burg • Miracles•Media • TakeNode 9a8affeb-120a-4484-a390-fe058ac64af4
A previous poster on this human islet work had been presented at the 4th International congress of the Cell Transplant Society, Montreux (Switzerland) March 21–24, 1999. See:
Optiprep For Human Islet Purification • Cell Transplant Society 1999 • Michel van der Burg • Miracles.Media • @1MEMO 20250203 • URL michelvanderburg.com/2025/02/03/
A previous talk on this human islet work had been presented Monday, 25 January 1999, at the 18th Workshop of the AIDSPIT Study Group in Igls , Austria. See :
Efficacy of the novel iodixanol-UWS density gradient for human islet purification • Igls Aidspit 1999 • Michel van der Burg • Miracles.Media • 20241202 • URL michelvanderburg.com/2024/12/02/
2) Innovative Islet Purification in Iodixanol-UWS • IPITA 97 • Michel van der Burg • Miracles.Media • @1MEMO 20250128 • TakeNode • URL michelvanderburg.com/2025/01/28/
Citation info : New Powerful Tool For Human Islet Purification • OptiPrep-UWS ? • IPITA 1999 Sydney • @1MEMO 20260325 • Michel van der Burg • Miracles.Media • URL michelvanderburg.com/2026/03/25/
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
Glycemic control mechanisms after canine islet autografting • IPITA 1995 • Michel van der Burg • Miracles.Media • @1MEMO 20251204_1 • Talk, Tuesday June 20, 1995 at 10:30, 5th IPITA, Eden Roc Resort Hotel, Miami Beach, FL (USA) • Digitally remastered by author, publisher, Michel van der Burg • TakeNode 5227c200-e029-4406-b344-15350fe3b93d • #GLP1 #GIP #diabetes #islets #transplant
Pioneer work on GLP-1 and GIP incretin hormones
Slideshow (digitally remastered) of my talk Tuesday June 20, 1995 at 10:30, at the 5th International Congress on Pancreas and Islet Transplantation (IPITA), in Miami Beach, FL (USA). My first talk at a world congress presenting the outcome of all our detailed metabolic studies in our preclinical model of canine islet autotransplantation , including our pioneer work on the incretin effects of the gut hormones GLP-1 (glucagon-like peptide-1) and GIP (Glucose-dependent Insulinotropic Polypeptide) — now, in 2025, well-known from the drugs that mimic the action of these natural hormones, to treat type 2 diabetes and obesity, by stimulating insulin release, improving blood sugar control, and reducing appetite.
May 1992 we were the first to show direct potentiation of the insulin response from isolated islets by (near-)physiological doses of both the gut hormones GLP-1 and GIP during perifusion (in vitro) of canine islets at 7.5-10 mM glucose levels (1,2), and January 1994 we next confirmed the incretin effect of a (near-)physiological dose of GLP-1 after canine islet transplantation , in a poster presented at the 13th Workshop of the AIDSPIT (aka AIDPIT) Study Group , Igls, Austria, January 23–25, 1994 (3).
Background of the work was posted earlier this year (4) and the work was published Nov 1994 in my PhD thesis Pancreatic islet transplantation , available online (5).
Welcome Reception 5th IPITA on Sunday 18 June 1995, at the congress venue , the Eden Roc Resort Hotel, in Miami Beach, FL (USA) • Michel van der Burg • Miracles.Media • @1MEMO 20251204_2 • TakeNode 8eb04df1-8280-4de3-a206-4b63413c3025
June 1995, 5th IPITA Talk
Tuesday June 20, 1995 at 10:30, at the 5th International Congress on Pancreas and Islet Transplantation (IPITA), in Miami Beach, FL (USA), was my first talk at a world congress presenting the outcome of all our detailed metabolic studies in the canine islet transplants , including the incretin effect of GLP-1, and also our findings with isolated canine islets during perifusion, in vitro, of the direct insulinotropic effects of the gut hormones GIP and GLP-1 (6) . That slideshow presentation (digitally remastered*) is posted here (1MEMO 20251204_1).
The proceedings paper delivered at the 5th IPITA is included in the Notes (7) , as well as the referenced previous papers (8,9)
Notes
1. 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 • URL https://michelvanderburg.com/2024/09/10/gut-factors-controlling-pancreatic-islets-20240910/
2. 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.
3. Metabolic control after canine islet transplantation. M.P.M. van der Burg, P.T.R. van Suylichem, O.R. Guicherit, J.H.M. van Deijnen, M. Frölich, and H.G. Gooszen (Universities of Leiden & Groningen, The Netherlands). Poster presented at the 13th Workshop of the AIDSPIT Study Group , Igls, Austria, January 23–25, 1994 • In : GLP-1 blood sugar regulation in islet transplants • AIDSPIT 1994 • Michel van der Burg • Miracles.Media • @1MEMO 20251114 • TakeNode 810cc881-d084-4d2e-b252-d432918b1946 • URL https://michelvanderburg.com/2025/11/14
5. Van der Burg MPM. Pancreatic islet transplantation: studies on the technique and efficacy of islet isolation and transplantation. (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 (Dec 4th, 2025) from Leiden University Scholarly Publications, Persistent URL https://hdl.handle.net/1887/3486604 .
6. Oral presentation : 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 20, 1995.
7. 5th IPITA Proceedings publication : 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. PDF available below PMID_8539903
8. Van der Burg MPM, Gooszen HG. The metabolic efficiency of islet grafts: an overview. In: Islet transplantation — current status of clinical application and experimental results. Hesse UJ , Pichlmaier H, Eds., Lengerich Germany, Wolfgang Pabst Verlag, 1992, p.93–99. Pabst hash code 0383b3abad3ae774b146ea0425c2227a PDF available below 1MEMO_20251204_4
9. Van der Burg MPM, Guicherit OR, Scherft JP, Lemkes HHPJ, Frölich M, Gooszen HG. Postprandial performance after canine islet transplantation: the importance of gut factors (Abstract). Neth J Med 1992; 41: A25. PDF available below 1MEMO_20251204_3
10. Van der Burg MPM, Guicherit OR, Van Suylichem PTR, Frölich M, Van Deijnen JHM, Gooszen HG. Importance of the entero-insular axis for islet graft function (Abstract). Cell Transplant 1994; 3: 257. Abstract – Second International Congress of the Cell Transplant Society May 1–4, 1994 Hyatt Regency Hotel • Minneapolis, Minnesota . https://doi.org/10.1177/096368979400300302 (Abstracts published , posters not presented). PDF available below 10.1177_096368979400300302
11. Chapter 8, Doctoral Thesis, Leiden University, November 1994 : Metabolic control after intrasplenic islet autotransplantation in dogs: ß-cell secretory capacity, insulin action, and the enteroinsular axis. Michael P.M. van der Burg, Paul T.R. van Suylichem, Onna R. Guicherit, Marijke Frölich, Herman H.P.J. Lemkes, and Hein G. Gooszen. In : Van der Burg MPM. Pancreatic islet transplantation: studies on the technique and efficacy of islet isolation and transplantation ( Chapter 8). (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 8 , URL https://scholarlypublications.universiteitleiden.nl/access/item%3A3486615/view .
12. Doctoral Thesis, Leiden University, November 1994 (Chapter 6) : lnsulinotropic properties of cholecystokinin, gastric inhibitory polypeptide, and glucagon-like peptide-1 during perifusion of short-term cultured canine isolated islets. Michael P.M. van der Burg, Onna R. Guicherit, Marijke Frölich and Hein G. Gooszen. In : Van der Burg MPM. Pancreatic islet transplantation: studies on the technique and efficacy of islet isolation and transplantation ( Chapter 6). (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 6 , URL https://scholarlypublications.universiteitleiden.nl/access/item%3A3486613/view
Full papers
13. 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.
14. 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. PDF link https://pure.rug.nl/ws/portalfiles/portal/58359942/096368979700600509.pdf
* 1MEMO 20251204_1 . Digitally remastered presentation, using the images from the original slides handout, and the handout of the text spoken during the original presentation , now read using my personal synthesized voice.
#GLP1 #GIP #diabetes #islets #transplant
Updates
Update 20260203 – added ResearchGate link ref 14
Citation info : Glycemic control mechanisms after canine islet autografting • IPITA 1995 • Michel van der Burg • Miracles.Media • @1MEMO 20251204 • URL https://michelvanderburg.com/2025/12/04
Front page Acta Diabetologica • Download Abstract Below
Abstract published in Acta Diabetologica 1998 of Iodixanol-UWS Human Islet Purification in 1998 at the Diabetes Research Institute in Miami. Abstracts book of the 18th Workshop of the AIDSPIT Study Group in Igls, Austria, Jan 1999.
Van der Burg MPM, Ranuncoli A, Molano R, Kirlew T, Ringers J, Bouwman E, Ricordi C. Efficacy of the novel iodixanol-UWS density gradient for human islet purification (Abstract). Acta Diabetol 1998; 35: 247. View / Download abstract (file 1MEMO_20251102_1.pdf) below .
Abstract added in full post : Efficacy of the novel iodixanol-UWS density gradient for human islet purification • Igls Aidspit 1999 • 20241202 • URL michelvanderburg.com/2024/12/02 •
Citation info : Iodixanol-UWS Human Islet Purification 1998 Abstract • Michel van der Burg • Miracles.Media • @1MEMO 20251102 • URL michelvanderburg.com/2025/11/02/
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)
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 .
2) Van der Burg MPM, Ranuncoli A, Molano R, Kirlew T, Ringers J, Bouwman E, Terpstra OT, Ricordi C. Optiprep for human islet purification (Abstract). Cell Transplant 1999; 8: 184. Download abstract below 1MEMO_20250202_3
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/
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/
