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Biomedical subjects

R J Corry

Publications and source records attributed to R J Corry.

At least 55 records · Page 3Linked to original sources
PubMed1991

Successful combined hepatic and pancreatic allograft retrieval in donors with a replaced right hepatic artery.

The parallel development of reconstructive techniques used to retrieve and transplant organs with vascular anomalies, and of techniques used in the multiple organ retrieval process, have facilitated the recovery of the maximal number of transplantable organs from a limited supply of donors. Recent contributions to this effort are descriptions of combined retrieval of both liver and whole organ pancreaticoduodenal allografts from the same multiple organ donor. Suggested contraindications for the retrieval of the latter allograft have included the presence of a replaced right hepatic artery originating from the superior mesenteric artery. We describe herein the techniques used in retrieving both the liver and the whole pancreas from donors with this vascular anomaly.

Adolescent↗
PubMed1990

Vascular response to cyclosporine and verapamil in the rat pancreas.

Marked elevation of vascular resistance in the rat pancreas is shown after systemic infusion of cyclosporine. Verapamil administration after cyclosporine reversed this effect and allowed maintenance of baseline vascular resistance and blood flow to the pancreas despite additional infusions of cyclosporine. Cyclosporine toxicity in rat pancreas may be directly related to increased vascular resistance. Verapamil might offer protection from this effect.

Animals↗
PubMed1990

Physiologic studies of urinary drained pancreaticoduodenal grafts in humans.

Exocrine function of urinary drained pancreas transplants (UDP) as determined by measurements of urinary pancreatic metabolites was assessed in 15 recipients. Normal UDP showed significantly higher levels (P less than 0.05) of urinary amylase, (42,931 +/- 5135 U/liter), HCO3 (27.12 +/- 3.18 meq/liter), and pH 7.83 +/- 0.15) than nine other recipients of enteric drained pancreas transplants with corresponding values of 168.00 +/- 2.00 U/liter, 3.20 +/- 0.20 meq/liter, and 6.08 +/- 0.27. These urinary metabolites dropped significantly (P less than 0.02) during rejection to 13,576 +/- 3446 U/liter, 19.22 +/- 5.74 meq/liter, and 7.06 +/- 0.14, respectively. These changes preceded elevation of blood sugar levels by 2-3 days. During rejection episodes, pancreatic grafts failed also to excrete bicarbonate and amylase significantly in response to secretion stimulation (P less than 0.05) contrary to nonrejecting pancreata. It is concluded that decreases in urinary amylase, HCO3, and pH observed with and without secretin stimulation are simple markers of pancreatic rejection.

Amylases↗
PubMed1990

Elimination of acute GVHD and prolongation of rat pancreas allograft survival with DST cyclosporine, and spleen transplantation.

Allogeneic spleen transplantation has been shown to have a tolerizing effect on pancreas allograft survival in rats. In this study we examined the effect of blood transfusions and cyclosporine administration on both rat pancreas allograft survival and acute graft-versus-host disease in BN recipients of Lewis pancreas-spleen allografts. We found that in this strain combination significant pancreas allograft prolongation occurred when the spleen was included en bloc with the pancreas graft. However, 50% of these recipients developed GVHD and died. A single donor-specific transfusion delivered to BN recipients of Lewis pancreas and pancreas-spleen allografts did not extend graft survival, but precluded the development of GVHD. A short, 6-day, and long, 26-day, course of CsA to recipients of pancreas and pancreas-spleen allografts extended graft and animal survival times, although not indefinitely. All pancreas-spleen recipients of both CsA protocols died following acute GVHD. Combined DST and CsA (short and long-course) administration in pancreas-only allograft recipients was deleterious to graft survival, compared with CsA administration alone. However, in pancreas-spleen recipients, combined DST and CsA had an additive effect. Moreover, in DST and long-course CsA-treated pancreas-spleen recipients, indefinite graft survival occurred with no signs of acute GVHD. The beneficial effect of the spleen allograft on pancreas graft survival was not dependent upon GVHD, since splenic-induced prolongation of pancreas graft survival was observed in the F1-donor to parent-recipient combination.

Acute Disease↗
PubMed1990

Quality of life in diabetic recipients of kidney transplants is better with the addition of the pancreas.

The present study is an evaluation of the quality of life of 32 patients following successful pancreatic transplantation. These patients were studied at from 6 months to 5 years post-transplantation. Over one-half of them were beyond the 21/2-yr mark. A questionnaire was developed that focused on symptoms of neuropathy, enteropathy, and retinopathy. All of the patients evaluated had completely normal carbohydrate metabolism, as evidenced by normal fasting blood sugars and hemoglobin A1C levels. Twenty-one of the 32 patients had symptomatic neuropathy pre-operatively, and 11 of these reported substantial subjective improvement. Eight remained unchanged and 2 became worse. Twenty-four patients had symptoms of enteropathy and 23 noted improvement post-transplantation. Retinopathy symptoms were not improved, but there was a suggestion that after 3 or 31/2 yr progression did not occur as rapidly as earlier. Virtually all of the patients had mood improvements and considerably less fatigue. We have determined that the risk of the procedure when receiving simultaneous renal and pancreas grafts is not significantly greater than that associated with a kidney transplant alone. Patients who are not uremic, either those with a successful kidney graft or those preuremic patients, are better candidates if symptoms are present. The risk of immunosuppression is insignificant in those patients who already have a successful renal transplant and are already on immunosuppressant drugs. Pancreatic transplantation can substantially improve the quality of life in diabetic patients, and should be considered as a therapeutic measure.

Diabetes Mellitus, Type 1↗
PubMed1990

Thrombosis in human pancreatic transplantation associated with elevated cyclosporine levels and possible protection by antihypertensive agents.

Acute thrombosis in human pancreatic transplantation (HPT) remains a serious problem occurring in 10% to 30% of many reported series. Thrombosis may result from a number of causes including technical error, acute rejection, or low-flow states secondary to conditions within the host or in the transplanted organ. Evidence accumulates suggesting cyclosporine (CSA) acts as a potent vasoconstricting agent and that antihypertensive medications such as calcium channel blocking agents may offer protection from this effect. We have reviewed 68 consecutive human pancreatic transplants at the University of Iowa, specifically evaluating CSA levels, and the use or nonuse of antihypertensive medications. We found CSA levels in patients with transplant thrombosis to be elevated above the mean in 80% of patients with levels available 24 hours prior to thrombosis. Fifty percent of these (CSA) levels were well above one standard deviation. In addition, those patients receiving routine antihypertensive medication (most commonly calcium channel blocking agents) were statistically less likely to have thrombosis of the pancreatic transplant. We suggest that elevated levels of CSA may play at least a partial role in thrombosis of HPT and antihypertensive agents may offer protection from this effect.

Adult↗
PubMed1989

Function of pancreas allografts more than 1 year following transplantation.

At the University of Iowa, Iowa City, 75 pancreas transplant procedures were performed for type I diabetes mellitus from March 1984 to September 1988. Forty-seven of these transplants were performed simultaneously with kidney transplants from the same donor; 23 followed previous kidney transplants, and 5 were preuremic pancreas-only transplants. The 1-year patient survival rate is 85% and pancreas graft survival rate is 54%. The simultaneous kidney and pancrease group had a 1-year patient survival rate of 82%, a pancreas graft survival rate of 59%, and a renal graft survival rate of 73%. Thirty-one of 70 kidney and pancreas recipients had a functioning pancreas 1 year post transplantation and 26 of 31 currently have a functioning pancreas and are insulin free. Patient symptoms of neuropathy and gastroenteropathy are improved with long-term graft function. Some patients may develop type II diabetes post transplantation with impaired glucose tolerance despite high insulin production by the graft. Pancreas transplantation is the only therapy that achieves a euglycemic state as indicated by glycosylated hemoglobin and glucose tolerance testing. Centers must continue to follow up patients on a long-term basis to determine the final effects on the secondary complications of diabetes.

Diabetes Mellitus, Type 1↗
PubMed1989

Increased frequency of posttransplant lymphomas in patients treated with cyclosporine, azathioprine, and prednisone.

We have documented seven B cell lymphomas over a six-month period in 132 (5.3%) kidney and heart allograft recipients immunosuppressed with cyclosporine, azathioprine, and prednisone (triple therapy). This is a significant increase (P less than 0.0001) over the number of such tumors seen by us previously. Only 2 lymphomas had occurred in 669 cadaver and 29 living-related kidney allografts treated with azathioprine and prednisone alone (0.3%). In 160 cadaver kidney recipients treated with cyclosporine and prednisone there have been no lymphomas. Similarly in 14 living-related kidney recipients who were transplanted since the introduction of triple therapy for cadaver grafts, but continued to receive only azathioprine and prednisone, no lymphomas occurred. There seemed to be a clear relationship between this increase and the use of triple therapy. This led us to examine other possible contributing factors. A case control study has not shown any other factor that differs in patients in whom lymphomas developed. We have only been able to demonstrate Epstein Barr virus nuclear antigen in the cells of one tumor. Four of these 7 tumors were monoclonal, one polyclonal, and two indeterminate. All patients had their immunosuppression withdrawn and six received intravenous acyclovir. Three patients have shown some response but four patients died. Triple therapy is being used by many centers to reduce the level of cyclosporine toxicity. We wish to sound a note of caution that this may result in an increased incidence of posttransplant lymphomas.

Adult↗
PubMed1989

Appearance of type II diabetes mellitus in type I diabetic recipients of pancreas allografts.

To determine the cause of hyperglycemia appearing after pancreas transplantation in type I diabetic recipients, we performed 65 oral glucose tolerance tests with serum insulin and C-peptide determinations in 32 patients with pancreas grafts functioning two or more months following transplantation. We correlated these results with estimates of graft size obtained by magnetic resonance imaging (MRI) and values of urinary amylase as a measure of pancreatic exocrine function. A total of 33 studies were obtained in 20 patients at times of normal glucose tolerance, and normal ranges for serum insulin and C-peptide levels were established; 32 studies in 17 patients during periods of glucose intolerance revealed values of serum insulin and C-peptide that were within the normal range, though the time to peak values was delayed to 2 hr, characteristic of type II diabetes. Only 3 of 17 patients examined by MRI had significant pancreatic allograft atrophy. These patients also had low urinary amylase excretion, and the only values for serum C-peptide that were below the normal range. The other 14 hyperglycemic patients had normalized pancreas grafts, normal urinary amylase excretion, and normal values for serum insulin and C-peptide. In our experience, then, in 76% of patients with hyperglycemia more than 2 months following pancreas transplantation, the cause was appearance of type II diabetes rather than destruction of the allograft with recurrence of type I diabetes. This observation has important implications for the definition of pancreas allograft failure and for the management of pancreas allograft recipients with hyperglycemia.

Amylases↗
PubMed1989

Pancreatic transplants: evaluation with MR imaging.

Eighty-eight magnetic resonance (MR) imaging studies of 31 pancreas transplants in 30 patients were performed. The postoperative graft usually appears enlarged and inhomogeneous, with patchy areas of increased signal intensity on T2-weighted images that may last 3-4 weeks. During acute rejection, T1-weighted images of graft abnormalities show a decrease in signal intensity, similar to that of muscle, and T2-weighted images show an increase in signal intensity, equal to or higher than that of the bladder. The pattern of abnormal signal is most frequently multifocal but can be diffuse, and the graft may be enlarged. During recovery from rejection, the graft parenchyma shows a decrease in signal intensity (less than that of the bladder) on T2-weighted images when compared with that of acute rejection. During chronic rejection the graft is small and shows low signal intensity, slightly higher than or similar to that of muscle, on both T1- and T2-weighted images. MR imaging appears to be useful for detection of early pancreas allograft rejection and complications in conjunction with clinical findings, laboratory data, and other radiologic procedures.

Acute Disease↗
PubMed1989

Application of magnetic resonance imaging in pancreas transplant.

Various imaging methods have been used in the differential diagnosis of pancreas-transplant dysfunction. As early as 1977, angiography and radionuclide studies ([75Se]seleno-DL-methionine) were used to evaluate pancreas allografts. More recently, the use of 99mTc-labeled DTPA, computed tomography, and ultrasonography has been described, and abnormal findings associated with rejection have been reported with these imaging methods. However, no attempt has been made to determine the ability of each method to detect rejection and to differentiate graft dysfunction caused by rejection from dysfunction by other causes. We summarize our experience with the application of magnetic resonance imaging (MRI) in pancreas transplantation and a comparative study of radionuclide 99mTc-DTPA scans, ultrasonography, and MRI in the detection and differentiation of pancreas-graft dysfunction.

Adult↗