Manuel Chee

Hypothermic Pulsatile Perfusion: Its Use in the Preservation of Pancreases for 24 to 48 Hours Before Islet Cell Transplantation

Canine pancreases underwent hypothermic pulsatile perfusion for 24 or 48 hours before islet cell collagenase digestion and intrasplenic autotransplantation. The numbers of dogs surviving longer than two months are as follows: dogs receiving pancreatectomies, 0/10; dogs receiving 24-hour-perfused islet cells, 6/10, dogs receiving 48-hour-perfused islet cells, 4/10; and dogs receiving fresh islet cells, 7/10. Islet cells from 48-hour-perfused pancreases were not as good in reversing hyperglycemia as the islet cells from 24-hour-perfused pancreases. Histologically, the islet cells appeared to be normal in the fresh and 24-hour-perfused pancreases. Thus, hypothermic pulsatile perfusion of pancreas autografts for 24 hours appears to be a safe and reliable method. When this technique is used clinically, special attention should be given to 48-hour-perfused pancreases because the reversal of hyperglycemia sometime is not complete.

Forty-eight hours hypothermic storage of whole canine pancreas allografts. Improved preservation with a colloid hyperosmolar solution.

Abstract This study indicates that crystalloid (Sacks) and colloid (modified silica gel fraction of plasma, MSGF) hyperosmolar solutions are edequate means to preserve whole pancreas allografts under hypothermia (4 to 7 °C) for 24 hr. These groups of preserved canine pancreas allografts survived as long as the fresh transplanted pancreas. However, when the preservation was extended to 48 hr, the crystalloid hyperosmolar solution did not protect the pancreas allografts, but the colloid hyperosmolar solution gave similar results to fresh pancreas allografts.

Effects of pulsatile perfusion pressure and storage on hearts preserved for 24 hours under hypothermia, for transplantation.

Canine hearts preserved for 24 hours under hypothermic pulsatile perfusion at a systolic pressure of 25 mm Hg had better perfusion and transplantation survival results than hearts perfused at 50 or 80 mm Hg. Also, hearts perfused at a systolic pressure of 25 mm Hg did better than simple hypothermically stored hearts or fresh allografts. These findings indicate that hearts are adequately perfused for 24 hours under hypothermia for transplantation at a systolic pressure of 25 mm Hg.

Liver preservation by cold storage with hyperosmolar solutions for twenty-four hours☆

Abstract Canine livers were successfully preserved in an ischemic state for 24 hr under hypothermic storage with hyperosmolar colloid or crystalloid solutions. Livers preserved with a colloid hyperosmolar solution (MSGF) showed slightly better survival results than the ones preserved with a crystalloid hyperosmolar solution. It is possible that hyperosmolarity associated with hyperkalemia is an important factor for liver preservation for transplantation.

Improvement of pancreas allograft survival after perfusion with concanavalin A

Abstract Perfusion with Con A significantly improved the survival of canine pancreas allografts minimally immunosuppressed. Control dogs and those that received no Con A survived for only short periods of time. When the immunosuppression to the recipient animals was increased by adding methylprednisolone, the prolonging effect of Con A was even more significant.

Effect of temperature upon heart preservation for transplantation

Abstract In this work we studied the effect of three different temperatures (7 °, 15 °, and 30 °C) on heart preservation. The best temperature for 24 hr pulsatile perfusion of canine hearts was 7 °C. Hearts perfused at this temperature showed no evidence of abnormal preservation changes nor of histological damage immediately upon transplantation. If the temperature was increased to 15 ° or 30 °C, moderate to severe preservation and histological damage were observed, and only three out of 10 dogs survived upon heart implantation.

Lung Transplantation: Better Survival Results after Graft Pretreatment with Concanavalin A or Chondroitin Sulfate

Pretreatment of the lung graft with concanavalin A (Con A) or chondroitin sulfate (CIS) was used to modify the lung allograft response after transplantation into moderately immunosuppressed (low doses of azathioprine and prednisone) recipients. Significant (p less than 0.05) prolongation of survival was observed after graft pretreatment. Pneumonia and rejection were the most frequent causes of death for all groups of dogs. However, only 3 out of 6 animals from each of the groups with pretreated grafts died of pneumonia or rejection, whereas 5 of the 6 animals in the control group died of these causes. Furthermore, when rejection occurred in the dogs with lung grafts pretreated with Con A or CIS, it was considerably delayed compared with the controls. Partial pressure of arterial oxygen, chest roentgenograms, and lung histology were good indicators of lung viability after transplantation.

Concanavalin A: Modification of Kidney Graft Immunogenicity in a Double Transplant Model

This study determines the effectiveness of flush graft pretreatment with concanavalin A (Con A) in minimally immunosuppressed recipients receiving double kidney transplantation. Significant prolongation of survival was seen when both kidneys from the same unrelated donor were treated with Con A, when both kidneys from different unrelated donors were treated with Con A, or when the allogeneic kidney was treated with Con A, and the syngeneic kidney was untreated. There was no significant prolongation in kidney allograft survival when one of the two allogeneic kidneys was treated with Con A, whether they came from the same, or different donors. If only the syngeneic kidney was treated with Con A and no treatment was given to the allogeneic kidney, also no prolongation of survival was observed. Thus, this study fully agrees with previous data indicating that Con A is not acting by systemic immunosuppression, but by local changes that modify the kidney immunogenicity. The theoretical implications associated with the prolongation of graft survival after flush pretreatment with Con A are activation of suppressor T cells, enhancement, physico-chemical modifications of the cell membrane and/or others.