338.1: Islet isolation after normothermic ex vivo machine perfusion of 2 discarded human pancreas allografts: A proof of concept study
Bibliographic record
Abstract
Background: Pancreas and islet transplantation are both therapeutic options for patients with complicated diabetes. Unfortunately, the availability of pancreas allografts is inadequate to cover the increasing recipient demand. Strategies to expand the number of available grafts are needed. Normothermic ex vivo perfusion (NEVP) is a method that has to potential to assess and repair organs. Our group has already successfully established a perfusion model of both porcine and human pancreas. This study aimed to assess the feasibility of islet isolation after NEVP of the pancreas. Methods: Two discarded human pancreas grafts were received by our team for perfusion. Backtable preparation was done in the usual manner with the additional cannulation of the aorta and portal vein, as well as the placement of a Malecot catheter on the distal side of the duodenum. Grafts were then placed on the machine and perfused for 4 hours on a NEVP circuit, previously developed, and described by our group. After the perfusion, biopsies were taken for H&E and insulin staining, and the organs were immediately processed for islet isolation using the Edmonton Isolation Protocol. Results: Both organs were successfully perfused for the established 4 hours with posterior islet isolation. Table 1 shows the donor, graft, and isolation characteristics. The pancreas morphological integrity was assessed by H&E staining and the islets’ integrity was evidenced by insulin staining. A glucose-stimulated insulin secretion test was performed on both cases (figure 1). Islets from both grafts responded appropriately, secreting insulin at high glucose concentrations. However, case #1 appeared to demonstrate a more robust response than case #2.Conclusions: Islet isolation after NEVP is feasible using the standard human isolation protocol and could be used to assess and improve the grafts destined for islet isolation. For this study, only the feasibility of the procedure after perfusion was assessed. To our knowledge, this is the first study reporting islet isolation after NEVP in human pancreas. Future studies will focus on improving the perfusion and thoroughly assessing the islets. References: 1. Shapiro J. Islet Transplantation in Seven Patients with Type 1 Diabetes Mellitus using a Glucocorticoid-Free Immunosuppresive Regimen. NEJM.2000; 343:230. 2. Ricordi C. Automated Method for Isolation of Human Pancreatic Islets. Diabetes.1988; 37:413-20 3. Mazilescu L. Normothermic Ex Situ Pancreas Perfusion for the Preservation of Porcine Pancreas Grafts. Am J Transplant. 2022 4. Parmentier C. Normothermic Ex Vivo Pancreas Perfusion for the Preservation of Pancreas Allografts before Transplantation. J Vis Exp.2022
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".