Experience with 450 adult porcine islet isolation procedures

Wennberg, Lars; Song, Z; Rydgård, K.J; Bennet, William; Nava, S; Lundgren, T; Sundberg, B; Groth, Carl‐Gustav; Korsgren, Olle

doi:10.1016/s0041-1345(01)02091-7

Cited by 5 publications

(10 citation statements)

References 1 publication

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“…with earlier reports (29,32), and led to our standard dose of 15,000-30,000 IE/kg. However, transplanting an ex- One recipient had returned to hyperglycemia on day 8 after two consecutive blood glucose measurements of ≥20 mM/L (dotted line).…”

Section: Immunosuppression Recipient Ratssupporting

confidence: 88%

“…Recalculated on a per day ba-a good quality graft, especially of porcine islets, have in many instances contributed substantially. Apart from a sis, rats in the present study received ±6.5 mg/kg/day, which is less than half of the dose in the Swedish studies series of sparsely documented studies (13,20,30), two recent articles reported successful transplantation of (15 mg/kg/day) in which additionally substantial dosages of MMF and leflunomide (32) or FTY720 (21) adult porcine islets in the rat (21,32). In both studies the graft survivals were alike and remarkably similar to the were given daily.…”

Section: Immunosuppression Recipient Ratsmentioning

confidence: 77%

“…Culture was only for 1 day and there were ma- tion of the graft. In the reported studies, islets were cultured for only 1 day and it was indicated in one of these studies that in vitro function was not optimal at that moment and clearly better on day 8 (29,32), suggesting that It was also assessed if the size of the graft was of group b, which received the standard starting dose of CsA on day 0 (40 mg/kg). Animals were sacrificed for histology at days 1, 3, and importance for the survival time.…”

Section: Immunosuppression Recipient Ratsmentioning

confidence: 99%

“…The aim of the present study was to evaluate the directly after isolation (7,21,30) or after a few days of culturing (29,32).…”

Section: Introductionmentioning

confidence: 99%

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Transplantation of Long-term Cultured Porcine Islets in the Rat: Prolonged Graft Survival and Recipient Growth on Reduced Immunosuppression

et al. 2010

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To evaluate whether further improvement in porcine islet xenotransplantation is feasible, a number of questions were addressed. Earlier we showed significant improvement in the nude mouse of the porcine islets by selection through long-term culture. Now these islets were tested in the stringent pig-to-rat model. Islets were isolated from adult pigs, cultured for 1.5-3 weeks and transplanted to rats. Possible rejection mechanisms were assessed by interference of the cellular response with cyclosporine A (CsA), blocking macrophages with gadolinium chloride (GdCl), and suppressing the humoral response with cyclophosphamide. Modifications in graft size and condition were analyzed. Untreated control recipients showed primary nonfunction (PNF). CsA treatment could fully overcome PNF and resulted in graft survival from 10 to over 134 days. Rejection was the main cause of function loss. Although rejection could not be prevented by intensifying the induction therapy, increased maintenance immunosuppression effectively blocked rejection, albeit at the expense of toxicity. Blocking the humoral response was ineffective; all grafts showed PNF. In contrast, depletion of macrophages fully prevented PNF. Combination of GdCl and CsA gave no additional effect, and grafts were rejected between 57 and 162 days. Generally, graft survivals were similar to those reported in the literature; however, long-term cultured islets required much less maintenance immunosuppression. Cessation of graft function was not always due to rejection; in some cases "islet exhaustion" was found, possibly caused by discrepancy between the graft size and the rapidly growing recipient. Neither the presence of damaged islet tissue in the graft nor the size of the graft exerted any influence on graft survival. On rejection, no real infiltration of the graft was seen; destruction gradually processed from the outside. The good functional capability of the cultured islets was illustrated by disappearance of the clinical symptoms and increase in body weight, which almost doubled in the long-term survivors.

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Section: Immunosuppression Recipient Ratssupporting

confidence: 88%

Section: Immunosuppression Recipient Ratsmentioning

confidence: 77%

Section: Immunosuppression Recipient Ratsmentioning

confidence: 99%

“…The aim of the present study was to evaluate the directly after isolation (7,21,30) or after a few days of culturing (29,32).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Transplantation of Long-term Cultured Porcine Islets in the Rat: Prolonged Graft Survival and Recipient Growth on Reduced Immunosuppression

et al. 2010

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“…Isolation of adult pig islets has also experienced significant improvements [5–10]. The development of superior enzymes for pancreatic dissociation, such as liberase, and the demonstration that transplantation of large numbers of adult pig islets can control blood glucose in diabetic baboons (albeit for short periods) adds further support to adult porcine islets as a viable tissue source.…”

Section: Which Type Of Islet Tissue?mentioning

confidence: 99%

Pancreatic islet xenotransplantation

O’Connell

2002

Xenotransplantation

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Prevention of oxidative stress in porcine islet isolation

et al. 2010

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High yields of pure and viable porcine islet cells (PICs) to be used for microencapsulation are crucial for successful xenotransplantation. Mechanical disruption of the pancreas, enzymes used for digestion, digestion temperature and time are among the factors known to cause oxidative stress and to impact on the yield, purity and viability of PICs. The aim of our study was to optimize conventional procedures in order to minimize the oxidative stress that occurs during the isolation and purification of PICs. Porcine pancreatic tissue was harvested at a local slaughterhouse, and 15 consecutive isolations of PICs were performed with a modified automated Ricordi method (Graz method) using a shorter digestion time, a lower digestion temperature and minimal mechanical stress. PICs were purified with the Lymphoprep density gradient medium. Purity and viability were assessed immediately after the isolation process and after overnight culture. PIC function was tested in glucose stimulation experiments and insulin concentration was determined by ELISA. Oxidative stress was assessed by measuring isoprostanes (IP), malondialdehyde (MDA) and lipase levels using a HPLC-based, colorimetric liquid assay or ELISA, respectively. The mean yield of PICs was 3479 +/- 542 IEQs/g pancreas, with 96.4% viability and 97.7% purity. There was no significant loss in PIC viability after overnight culture. Insulin secretion in response to glucose was not impaired after isolation and purification. IP, MDA and lipase levels did not change significantly during the isolation procedure. With our new Graz method we seem to have succeeded in preventing oxidative stress and achieving high yields of pure and viable PICs.

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Experience with 450 adult porcine islet isolation procedures

Cited by 5 publications

References 1 publication

Transplantation of Long-term Cultured Porcine Islets in the Rat: Prolonged Graft Survival and Recipient Growth on Reduced Immunosuppression

Transplantation of Long-term Cultured Porcine Islets in the Rat: Prolonged Graft Survival and Recipient Growth on Reduced Immunosuppression

Pancreatic islet xenotransplantation

Prevention of oxidative stress in porcine islet isolation

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