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S R Munn

Publications and source records attributed to S R Munn.

At least 37 records · Page 2Linked to original sources
PubMed1991

The effect of somatostatin 201-995 on the early course of porcine pancreaticoduodenal allotransplantation.

This study was undertaken to determine the effects of somatostatin 201-995 (SMS) on the maintenance dose of intravenous cyclosporine and on graft blood flow, exocrine secretion, and rejection after porcine pancreaticoduodenal allotransplantation (PDA). For seven days, 12 pigs (6 control, 6 SMS-treated) were studied to determine the effects of SMS on serum CsA concentrations. Twenty-six pigs (14 control, 12 SMS) with streptozocin-induced diabetes underwent PDA. Blood flow was measured through graft celiac and superior mesenteric arteries 15 and 60 min after reperfusion. SMS (75 micrograms s.c.) was given after the 15-min blood-flow measurement in the SMS group. Sixteen pigs (8 control, 8 SMS) were followed postoperatively with daily measurements of serum glucose and amylase concentrations, and urine amylase and trypsin activities. All pigs were immunosuppressed with azathioprine, prednisone, and i.v. CsA. SMS pigs also received SMS (75 micrograms s.c.) every 8 hr. SMS had no effect on maintenance dose of CsA or on serum amylase, urine amylase, or urine trypsin activities. Mean days to rejection were also not affected. Intraoperative graft blood flow was significantly decreased by SMS, but incidence of graft thrombosis was unchanged. These results suggest that in the porcine PDA model, SMS does not appear to inhibit exocrine secretion and potentially may adversely affect the early course of PDA by decreasing graft blood flow.

Animals↗
PubMed1990

Pancreas transplantation at Mayo: II. Operative and perioperative management.

Better perioperative and operative management techniques have contributed to an improvement in the success rate of pancreas transplantation. Because of a shortage of donor organs, the criteria for acceptability of the allograft have been liberalized, and the development of techniques such as combined liver and pancreas procurement has increased allograft availability. Major advances have been made in organ preservation. Currently, pancreas allografts can routinely be stored for 18 to 24 hours. The technique of pancreaticoduodenal transplantation with a duodenocystostomy for the exocrine drainage is widely used. Experience with anesthetic and intensive-care unit management of these patients is accumulating. With the evolution of pancreas transplantation and with the help of the excellent transplant centers in our area, we developed a pancreas transplantation protocol and performed transplantation based on this protocol in 16 recipients at the Mayo Clinic from October 1987 through December 1988.

Adult↗
PubMed1990

Pancreas transplantation at Mayo: III. Multidisciplinary management.

Although pancreas transplantation is a complicated procedure, a good level of success has been achieved because of the introduction of cyclosporine for immunosuppression, improved methods for diagnosing rejection, and a multidisciplinary approach to management. Our immunosuppressive regimen was quadruple therapy with induction by using Minnesota antilymphoblastic globulin. A biopsy technique was instituted in which the pancreas specimens were obtained under cystoscopic direction during episodes of hypoamylasuria. The criteria for rejection episodes were not only biochemical abnormalities but also histologic confirmation and a follow-up to exclude other causes of graft dysfunction. Infectious disease management included use of oral selective bowel decontamination for 3 weeks after transplantation. At the Mayo Clinic between October 1987 and December 1988, 16 patients received pancreaticoduodenal allografts (both kidney and pancreas in 13 and pancreas only in 3 after a prior successful kidney transplantation). In two pancreas and one kidney allograft, function was lost. One patient died of multiorgan failure. The cystoscopically directed biopsy technique was performed 23 times with minimal complications and a 93% success rate. The metabolic results have been excellent; the glycosylated hemoglobulin level was normal 3 to 6 months after transplantation. The quality of life was significantly improved in almost all patients. Nutritional assessment revealed little deterioration after transplantation. With a multidisciplinary approach, the needed answers about the effect of pancreas transplantation on the degenerative complications of diabetes should be forthcoming.

Adult↗
PubMed1990

Differential diagnosis of hypoamylasuria in pancreas allograft recipients with urinary exocrine drainage.

We have studied the histopathologic correlates of a significantly decreased urinary amylase excretion rate (UAER) to determine its reliability in predicting the presence of cellular rejection within pancreas allografts drained via a duodenocystostomy. Significant hypoamylasuria in pancreas allograft recipients was defined as a diminution of greater than 50% in UAER sustained for greater than 36 hr and not associated with a decrease in serum amylase activity. We observed 18 such episodes of hypoamylasuria in 13 of 18 patients receiving pancreas allografts. Pancreaticoduodenal material was obtained during 11 of these episodes, one attempt failed, and for the remaining 6 episodes we obtained 3 renal allograft biopsy specimens. Histopathologic examination of the 14 specimens revealed cellular rejection in 9 (64%), fibrosis in 2 (14%), enzymatic necrosis in 1 (7%), cytomegaloviral pancreatitis in 1 (7%), and no abnormal features in 1 (7%). During these 14 episodes, a genetically identical renal allograft was present for 11 and showed signs of dysfunction in 9; however, the pancreatic histologic features suggested rejection in only 7 of the 9. Thus even the combination of hypoamylasuria and renal dysfunction in recipients of genetically identical organs was not fully reliable in predicting pancreas allograft rejection. In addition, the interval between organ implantation and onset of hypoamylasuria did not predict the histologic diagnosis. As with other solid-organ allografts, biopsy is a useful adjuvant for determining patient management in the presence of organ dysfunction.

Amylases↗
PubMed1990

Evidence that the soluble interleukin 2 receptor level may determine the optimal time for cystoscopically-directed biopsy in pancreaticoduodenal allograft recipients.

In 18 consecutive pancreaticoduodenal allograft recipients (15 combined kidney/pancreas and 3 pancreas only after a prior successful kidney transplantation) operated on between December 1987 and February 1989, we studied the soluble interleukin 2 receptor (SIL-2R) level over time. All pancreaticoduodenal allografts were transplanted with exocrine drainage via a duodenocystostomy that allowed for cystoscopically directed needle biopsies of the pancreas. Of these 18 recipients, at 6 weeks after transplantation, 6 had had no rejection episodes or cytomegalovirus disease (control group), an acute allograft rejection had developed in 7, CMV disease developed in 4, and both rejection and CMV disease developed in 1 by 12 days after transplantation. SIL-2R level increased in all patients during immunosuppressive induction therapy (preoperative mean +/- SE, 1637 +/- 284 U/mL; maximum, 4367 +/- 687 U/mL). After induction therapy, the mean was 2768 +/- 432 U/mL. In all 6 recipients in the control group, SIL-2R level continued to decrease. However, SIL-2R level was significantly higher compared with controls, in those who had CMV disease (levels were increased at a mean of 7 days before diagnosis of CMV disease) and in those who had acute rejection episodes (levels were increased a mean of 7 days before the clinical diagnosis of rejection). Factors that did not cause an increase in SIL-2R level included acute pancreatitis, wound infection, operative procedures, and CsA nephrotoxicity. SIL-2R level can be useful for monitoring pancreaticoduodenal allograft recipients. Increases predict impending rejection or CMV disease, prior to the onset of organ dysfunction. When SIL-2R level increases, we recommend cultures of blood and urine to exclude CMV and pancreaticoduodenal allograft biopsy to confirm early rejection prior to the initiation of potentially dangerous antirejection therapy.

Biopsy↗
PubMed1990

Purified canine islet autografts. Functional outcome as influenced by islet number and implantation site.

Using a modification of the basic principles of pancreatic intraductal collagenase digestion and density gradient purification to isolate canine islets, in conjunction with simultaneous fluorogenic and dithizone islet staining, we quantified the yield, purity, and viability of the isolated islets. We then determined the combined influences of total and weight-corrected islet counts and implantation site on immediate and long-term functional outcome of purified canine islet autografts. Weight-corrected islet counts were 100% sensitive and specific in differentiating successful and unsuccessful islet autografts implanted to the liver (n = 10) and spleen (n = 10) of pancreatectomized dogs. The threshold number of islets required to achieve normoglycemia in the liver (4400 islets/kg) and spleen (4650 islets/kg) were nearly identical. Islet autografts failed to ameliorate hyperglycemia when implanted to the renal subcapsular space (n = 5) at counts of 4400 to 5500 islets/kg. The mean one- and three-month intravenous glucose tolerance test K-values of dogs with purified islet autografts to the liver (-1.43 +/- 0.27 and -1.69 +/- 0.27, respectively) and spleen (-1.78 +/- 0.36 and -1.64 +/- 0.3, respectively) were also similar. Time needed to achieve normoglycemia , however, was significantly (P less than 0.02) shorter for intrahepatic islets (1.0 +/- 0.0 days posttransplant) than intrasplenic islets (6.8 +/- 2.3 days posttransplant). The long-term durability of islet autograft function was not unlimited. Overall, thirteen canine islet autograft recipients have been followed for greater than or equal to 12 months posttransplant (range 12-18 months), seven canine islet autograft recipients (five intrahepatic and two intrasplenic) have had spontaneous recurrence of hyperglycemia at 2, 6, 11, 13, 14, 8, and 16 months, respectively. The phenomenon depended only on the number of islets implanted. The data underscore the significance of quantitatively defined islet preparations and the importance of islet number and implantation site on immediate and long-term functional outcome of canine islet autografts.

Animals↗