Quantification of canine pancreatic islet isolation • 1st IPITA 1988 • @1MEMO 20251206


Quantification of canine pancreatic islet isolation • 1st IPITA , Stockholm (Sweden) March 27–29 1988 • Digitally remastered by author, publisher, Michel van der Burg • Miracles•Media • 1MEMO_20251206_01 • TakeNode 430989b2-52f0-4e36-8dbd-cf7bf030668c • #IEQ #diabetes #islets #transplant #methods #LUMC #IPITA

After founding the Leiden Islet Laboratory (1) in the University Hospital Leiden in Holland (later known as LUMC), and reporting the outcome of our first year of canine islet research at a national meeting November 1987 (2), next, this first poster ‘Quantification of canine pancreatic islet isolation’ for a world congress was presented March 1988 at the First International Congress on Pancreatic and Islet Transplantation (IPITA)* in Stockholm, Sweden (3,4).

This pilot work introduced our novel approach of volume quantification of islet isolation outcome by measuring the volume of the isolated islets . In addition we compared the outcome with the total volume of islets measured in the canine pancreas.
Note, that a similar approach, using islet volume measurements for the quantification in islet isolation assessment in man and large animals, was proposed the next year in an International Workshop during the 2nd Congress on Pancreas and Islet Transplantation, Sep. 1989, in Minneapolis, by Camillo Ricordi and some 150 participants from 30 institutes actively involved in islet isolation and transplantation — proposing a procedure for standardized islet volume measurements (based on the number of islets in diameter classes incrementing 50 µm) and reporting outcome in Equivalent Islet Numbers (total volume expressed in the equivalent number of spheres with a 150 µm diameter; abbreviated as EIN, currently known as the number of IEQs (Islet EQuivalents), which greatly enhanced islet research (5).

Unfortunately back problems prevented me to attend that 1st IPITA congress, I was looking forward to, but, fortunately, the poster was presented by my colleagues Hein Gooszen (Surgery Department) and Marijke Frölich (Chemical Pathology Department) of the University Hospital Leiden. Ms. Marijke Frölich also presented a nice poster (7,8) on our quantification of the islets cells , the hormones, in the right lobe (aka , the duodenal segment , the ventral lobe) and left lobe of the canine pancreas (aka, the body and distal tail , the dorsal lobe) of the beagle pancreas , showing the diversity of the islets in these two segments of the pancreas — corresponding to the head and tail of the human pancreas, respectively.
Below the excellent airbrush work by an artist from the Audiovisual Services of Leiden University, for our poster ‘Distribution of insulin, glucagon, pancreatic polypeptide and somatostatin in the canine pancreas’.

Airbrush art on poster board created by the Audiovisual Services of Leiden University. Showing the location of pancreatic tissue sampled from the proximal and distal part of the right and left lobe of the beagle pancreas. The hormone values did not differ significantly between the proximal and distal parts of each lobe. Michel van der Burg • Miracles•Media • 1MEMO_20251206_02 • TakeNode 10b1d696-9d7f-4fa3-a8f9-7a3211546f24


Poster board showing the distribution of the four different types of islet cells by assessment of the hormones insulin, glucagon, pancreatic polypeptide, and somatostatin between the right lobe (RL) and left lobe (LL) of the canine pancreas. The number of insulin, glucagon, and PP producing islet cells differs considerably between both lobes. Michel van der Burg • Miracles•Media • 1MEMO_20251206_03 • TakeNode 47333616-b85d-404e-b103-2ccb3b86d406

I created the original 1988 poster ‘Quantification of canine pancreatic islet isolation’ on March 9-10, 1988 using MacDraw on a personal Macintosh ED , using the bold Chicago font, and the Imagewriter-II matrix printer , except for the header provided by my colleagues , which was together with my colleagues’ posters designed and produced as usual at the time on rigid foam boards by the Audiovisual Services department of the Leiden University. Also the original photo print was pinned on the mounted poster (thus, not digitally processed at the time).
This digital remastered 2025 edition (1MEMO_20251206_1) was produced in LibreOffice Vanilla with conversion of the original 1988 MacDraw file, correcting the disrupted formatting, replacing the non-available Chicago font with the font ‘Chalkboard’ , adding a scan of the Figure 1 photo print , plus a recent photo taken of the original poster board, archived, header. Figure 1 uses a copy of that original photo print , with the addition now, in this remastered edition, of arrows helping identifying the islets , and addition of the text ‘(arrrows)’ in the figure legend.

Other papers presented at the 1st IPITA congress from our research group, on pancreas transplantation, are listed below (9,10,11,12).

David Sutherland

Several other centers reported at this 1st IPITA on succesful islet autotransplantation in large animals, including a series of presentations on canine islet transplantation from David Sutherland’s islet research group in Minneapolis.

We had already started collaborating, by the end of 1987, with David Sutherland and Ms. Jane Field , the head of Sutherland’s islet research laboratory in Minneapolis , planning Jane’s working visit for June 1988 in our Leiden Islet Laboratory, in order to help me set up in Leiden, the current Minneapolis procedure for canine islet isolation and transplantation (13,14).

The next year, Sep-Oct 1989, I worked again with Jane Field and David Sutherland, now in Minneapolis (14,15,16) in the islet research laboratory mostly, and also observing David Sutherland at work during clinical segmental pancreas autotransplantaton, where I made this portrait photograph (1MEMO_20251206_06).

David Sutherland • Clinical Pancreas Transplant, Minneapolis, 1989 • Michel van der Burg • Miracles.Media • 1MEMO_20251206_06 • TakeNode f4769bdf-c7a8-436a-bc5c-2d1505226c05 • David Sutherland performing a clinical segmental pancreas autotransplantation, Minneapolis, 1989. Photo by Michel van der Burg . URL https://michelvanderburg.com/2025/12/06

David Sutherland, the ‘father’ of pancreas and islet transplantation, passed away March 25, 2025.

David jokingly called the pancreas the “Big Dirty Island”.

Notes

* The founding meeting of the IPITA was being held actually at the 4th IPITA meeting — the 4th International Congress on Pancreas and Islet Transplantation — June 27–30, 1993 in Amsterdam (The Netherlands) hosted by Dr. Reinout van Schilfgaarde.

1. Leiden Islet Laboratory History • 20240803 • Michel van der Burg • michelvanderburg•com • URL https://michelvanderburg.com/2024/08/03/leiden-islet-laboratory-history-20240803/

2. Cradle of Islet Transplants • 20240829 • Michel van der Burg • michelvanderburg•com • https://michelvanderburg.com/2024/08/29/cradle-of-islet-transplants-20240829/

3. Van der Burg MPM, Gooszen HG, Terpstra JL, Frölich M, Scherft JP, Lemkes HHPJ. Quantification of canine pancreatic islet isolation. First International Congress on Pancreatic and Islet Transplantation, Stockholm (Sweden) March 27–29, 1988. (Poster). Remastered 2025 poster edition : 1MEMO_20251206_01.

4. Van der Burg MPM, Gooszen HG, Terpstra JL, Frölich M, Scherft JP, Lemkes HHPJ. Quantification of canine pancreatic islet isolation (Abstract). Diabetes 1989; 38 (Suppl. 1): 274. (Abstract). View/Download file 1MEMO_20251206_04

5. Quantitative And Qualitative Standards For Islet Isolation Assessment In Man And Large Mammals. International Workshop during the 2nd Congress on Pancreas and Islet Transplantation. Camillo Ricordi. Archive Michel van der Burg • Miracles•Media • 1MEMO_20251206_07 • TakeNode 3d90aa54-9fe1-4b29-8161-aa6c4fda6652 • View/Download file 1MEMO_20251206_07

6. 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.

7. Frölich M, Van der Burg MPM, Gooszen HG, Jansen JBMJ, Lamers CBHW. Distribution of insulin, glucagon, pancreatic polypeptide and somatostatin in the canine pancreas. First International Congress on Pancreatic and Islet Transplantation, Stockholm, Sweden, March 27–29 1988. (Poster).

8. Frölich M, Van der Burg MPM, Gooszen HG, Jansen JBMJ, Lamers CBHW. Distribution of insulin, glucagon, pancreatic polypeptide, and somatostatin in canine pancreas (Abstract). Diabetes 1989; 38 (Suppl. 1): 257. (Abstract) . Download file 1MEMO_20251206_04

9. Gooszen HG, Van der Burg MPM, Guicherit OR, Jansen JBMJ, Van Schilfgaarde R, Lamers CBHW, Frölich M. A crossover study on the effects of duct obliteration, coeliac denervation and autotransplantation on glucose and meal stimulated insulin, glucagon and pancreatic polypeptide levels. First International Congress on Pancreatic and Islet Transplantation, Stockholm, Sweden, March 27–29 1988. (Talk).

10. Gooszen HG, van der Burg MP, Guicherit OR, Jansen JB, Frölich M, van Schilfgaarde R, Lamers CB. Crossover study on effects of duct obliteration, celiac denervation, and autotransplantation on glucose- and meal-stimulated insulin, glucagon, and pancreatic polypeptide levels. Diabetes. 1989 Jan;38 Suppl 1:114-6. doi: 10.2337/diab.38.1.s114. PMID: 2642831. (Proceedings paper).

11. Gooszen HG, Van Schilfgaarde R, Van der Burg MPM, van Lawick van Pabst WP, Frölich M, Bosman FT. Quantitative assessment of changes in insulin secretion after canine ductobliterated segmental pancreatic autotransplantation in relation to the histological background. First International Congress on Pancreatic and Islet Transplantation, Stockholm, Sweden, March 27–29 1988. (Poster).

12. Gooszen HG, Van Schilfgaarde R, Van der Burg MPM, Van Lawick van Pabst WP, Frölich M, Bosman FT. Quantitative assessment of changes in insulin secretion after canine duct-obliterated segmental-pancreas autotransplantation in relation to histological background (Abstract). Diabetes 1989; 38 (Suppl. 1): 255–256. (Abstract). View/Download file 1MEMO_20251206_05

13. December 1987 , we started planning together Jane Field’s working visit thanks to our nephrologist Fokko van der Woude who after post doc research in Minneapolis had just started as an associate Professor at the Leiden University , working in our Leiden University Hospital (LUMC). Fokko J. van der Woude (1953-2006) passed away too soon after a long battle with cancer.

14. Pancreas & Islet Transplantation Program • 20240912 • Michel van der Burg • michelvanderburg•com • URL https://michelvanderburg.com/2024/09/12/pancreas-islet-transplantation-program-20240912/

15. Visiting research fellow in the Department of Surgery at the University of Minnesota (DER Sutherland, MD PhD) & Department of Cell Biology (OD Hegre, MD PhD), University of Minnesota, Minneapolis Minnesota (USA) , September 14-October 6 1989

16. 2nd International Congress on Pancreatic and Islet Transplantation, and 4th International Symposium on Organ Procurement and Preservation. Minneapolis (USA) September 17–22, 1989.

Citation info : Quantification of canine pancreatic islet isolation • 1st IPITA 1988 • Michel van der Burg • Miracles.Media • @1MEMO 20251206 • URL https://michelvanderburg.com/2025/12/06

Glycemic control mechanisms after canine islet autografting • IPITA 1995• @1MEMO 20251204

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

4. Background of this work was posted in Dutch Islets Transplant Team • @1MEMO 20250125 • URL https://michelvanderburg.com/2025/01/25/dutch-islets-transplant-team-1memo-20250125/

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

Referenced previous publications :

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

Other previous publications :

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

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

Milan Papers • @1MEMO 20250205

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

3) Abstracts

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

Citation info : Milan Papers • Michel van der Burg • Miracles.Media • @1MEMO 20250205 • URL michelvanderburg.com/2025/02/05/

Innovative Islet Purification in Iodixanol-UWS • IPITA 97 • @1MEMO 20250128

No porcine islet loss during density gradient purification in a novel iodixanol in University of Wisconsin solution. First talk on our introduction of the innovative Iodixanol-UWS density gradients for islet purification , showing no islet loss in the difficult model of pig islet isolation — presented at the 6th IPITA congress in Milan (Italy) , Thursday, 25th september 1997 (1).

Background

In 1995 the Leiden Islet Lab had moved into the Surgery Lab in the new LUMC building, and the islet team had grown, focussing on xenotransplantation. With more people isolating pig islets, more convenient islet isolation solutions were tried.

Both Percoll-UWS (2) and Histopaque-UWS (3) were being used from 1992 in first series of islet isolations from juvenile pig pancreases.

August 1995, I started designing the clinical promising islet purification solution of Iodixanal in UW-Solution (UWS). I mixed Optiprep – a 60 % solution of iodixanol in water – with a 2-times concentrated UWS, to prepare this density gradient solution. The first standard operation procedure of this Iodixanol-UWS gradient for our pig islet isolation research was completed November 1995.

This purification solution was a logical follow-up of our highly succesful Percoll-UWS density gradient (2) — a similar solution of impermeants (that do not readily enter cells) with similar osmolarity (close to that of the tissue) , more practical though, and with the important advantage that iodixanol is clinical tested.

July 1996, I introduced the Iodixanol-UWS gradient to replace the Percoll-UWS gradient for large scale pancreatic islet research in this difficult model of islet isolation from juvenile pig pancreases.

The work was presented September 1997. First a poster was presented that month at the Xenotransplantation Congress in Nantes , France (4). Next, two talks followed at the 6th Congress of the International Pancreas and Islet Transplant Association (IPITA) in Milan (Italy).

Here the (remastered) slideshow of that first talk at the 6th IPITA Congress in Milan, presented Thursday, 25th september 1997 (1) . The slideshow of the 2nd talk , presented at the last day of that congress, was posted yesterday (5).

Notes

1) 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. Sixth Congress of the Int. Pancreas and Islet Transplant Association (IPITA), Milan (Italy) Sept. 24–27, 1997.

2) Percoll UWS Purification Pancreatic Islets • ESOT 1991 Talk • Michel van der Burg • Miracles.Media • @1MEMO 20250114 • URL michelvanderburg.com/2025/01/14/

3) Basir I, van der Burg MPM, Scheringa M, Töns A, Bouwman E. Improved outcome of pig islet isolation by Pefabloc inhibition of trypsin. Transplant Proc. 1997 Jun;29(4):1939-41. doi: 10.1016/s0041-1345(97)00168-1. PMID: 9193462

4) Van der Burg MPM, Basir I, Bouwman E. Non-traumatic porcine islet density gradient purification in a novel iodixanol in University of Wisconsin solution. The 4th Int. Congress for Xenotransplantation, Nantes (France) Sept. 7–11, 1997. Online in : Purification Islets in Iodixanol-UWS • Leiden Start 1996 • Michel van der Burg • Miracles.Media • @1MEMO 20250126 • URL michelvanderburg.com/2025/01/26/

5) Van der Burg MPM, Basir I, Zwaan RP, Bouwman E. Porcine islet preservation during isolation in University of Wisconsin solution. Sixth Congress of the Int. Pancreas and Islet Transplant Association (IPITA), Milan (Italy) Sept. 24–27, 1997. Online in : Porcine Islet Preservation In UWS • IPITA 97 • Michel van der Burg • Miracles.Media • @1MEMO 20250127• URL michelvanderburg.com/2025/01/27/

Milan Papers • @1MEMO 20250205 • Manuscripts (Preprints) and Abstracts copies of the presentations at the IPITA 1997 meeting in Milan (Italy). PDF downloads at michelvanderburg•com/2025/02/05/

Citation info : Innovative Islet Purification in Iodixanol-UWS • IPITA 97 • Michel van der Burg • Miracles.Media • @1MEMO 20250128 • TakeNode • URL michelvanderburg.com/2025/01/28/

Porcine Islet Preservation In UWS • IPITA 97 • @1MEMO 20250127

August 1995, I started designing the clinical promising islet purification solution of Iodixanal in UW-Solution (UWS). I mixed Optiprep – a 60 % solution of iodixanol in water – with a 2-times concentrated UWS, to prepare this density gradient solution. The first standard operation procedure of this Iodixanol-UWS gradient for our pig islet isolation research was completed November 1995.

This purification solution was a logical follow-up of our highly succesful Percoll-UWS density gradient — a similar solution of impermeants (that do not readily enter cells) with similar osmolarity (close to that of the tissue) , more practical though, and with the important advantage that iodixanol is clinical tested.

The Leiden Islet Lab had just moved into the Surgery Lab in the new LUMC building, and the islet team had grown, focussing on xenotransplantation. With more people isolating pig islets, more convenient solutions were tried.

Both Percoll-UWS and Histopaque-UWS were being used from 1992 for small scale islet isolations from juvenile pig pancreases.

July 1996, I introduced the Optiprep-UWS gradient to replace our Percoll-UWS gradient for larger scale porcine islet isolations.

The work was first presented September 1997, both in a poster presented at the Xenotransplantation Congress in Nantes , France (1), and later that month in two talks at the 6th Congress of the International Pancreas and Islet Transplant Association (IPITA) in Milan (Italy). The slideshow of the first talk (2) will be online at this site soon.
Here the remastered slideshow of the 2nd talk at the 6th IPITA Congress in Milan, presented Saturday, 27th September, 1997 (3).

Notes

1) Van der Burg MPM, Basir I, Bouwman E. Non-traumatic porcine islet density gradient purification in a novel iodixanol in University of Wisconsin solution. The 4th Int. Congress for Xenotransplantation, Nantes (France) Sept. 7–11, 1997. Online in : Purification Islets in Iodixanol-UWS • Leiden Start 1996 • Michel van der Burg • Miracles.Media • @1MEMO 20250126 • URL michelvanderburg.com/2025/01/26/

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. Sixth Congress of the Int. Pancreas and Islet Transplant Association (IPITA), Milan (Italy) Sept. 24–27, 1997.

3) Van der Burg MPM, Basir I, Zwaan RP, Bouwman E. Porcine islet preservation during isolation in University of Wisconsin solution. Sixth Congress of the Int. Pancreas and Islet Transplant Association (IPITA), Milan (Italy) Sept. 24–27, 1997.

Milan Papers • @1MEMO 20250205 • Manuscripts (Preprints) and Abstracts copies of the presentations at the IPITA 1997 meeting in Milan (Italy). PDF downloads at michelvanderburg•com/2025/02/05/

Updates

Update 20250128 – update intro design timeline

Update 20250205 – added link to manuscripts and abstracts

Citation info : Porcine Islet Preservation In UWS • IPITA 97 • Michel van der Burg • Miracles.Media • @1MEMO 20250127 • TakeNode 6d6fca2e-014c-40cf-8110-725b267c0b0e • URL michelvanderburg.com/2025/01/27/

Dextran Density Purification Of Pancreatic Islets • @1MEMO 20250104

Dextran Poster 3rd IPITA 1991 • Michel van der Burg • Miracles.Media • 20250104_1 • TakeNode 1c05b2a5-de41-4185-b304-fee2335100f3

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).

Background

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.

Dextran UW Gradient • First density gradient in UW-Solution

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).

Notes

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/

Iodixanol Purification of Porcine Islets • Sydney IPITA 1999 • 20241203

Slides oral presentation Michel van der Burg, IPITA congress 1999 in Sydney, Australia

A novel iodixanol density gradient for purification of pancreatic islets was developed in the difficult pig model. The pig islets restored normal blood sugar levels after xeno transplantation in diabetic mice.


Slideshow (pdf) oral presentation Michel van der Burg, IPITA congress 1999 in Sydney, Australia

Recovery of adult pig islets during isolation using Liberase vs collagenase-P, purification in OptiPrep-UWS, and culture for transplantation in nude mice • Sydney IPITA 1999 • Michel van der Burg • Miracles.Media • @1MEMO 20241203_2 • TakeNode 5f53ae49-6fb8-4bef-a434-ac2ce8151c2a • File 1MEMO_20241203_2

Van der Burg MPM, Rijkelijkhuizen JKRA, Zwaan RP, Bouwman E. Recovery of adult pig islets during isolation using Liberase vs collagenase-P, purification in OptiPrep-UWS, and culture for transplantation in nude mice. 7th World congress of the International Pancreas & Islet Transplant Association, Sydney (Australia) August 22–25, 1999

Citation info : Iodixanol Purification of Porcine Islets • Sydney IPITA 1999 • Michel van der Burg • Miracles.Media • 1MEMO 20241203 • TakeNode ea1f1abd-6227-4ae6-985b-f8188310cd24 • URL michelvanderburg.com/2024/12/03/