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Biomedical subjects

F H Wright

Publications and source records attributed to F H Wright.

At least 19 recordsLinked to original sources
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↗
PubMed1985

Immunoreactive luteinizing hormone, estradiol, progesterone, testosterone, and androstenedione levels during the breeding season and anestrus in Siberian tigers.

Seasonal analysis of 1239 captive births of Siberian tigers (Panthera tigris altaica) indicated a peak in April to June (P less than 0.001). Studies on seven animals in Minnesota indicated that behavioral heat cycles and ovarian follicular phase cycles began in late January and ceased in early June. Behavioral observation of 12 heat cycles in four tigers yielded an estrous length of 5.3 +/- 0.2 days and an interestrous interval of 25.0 +/- 1.3 days. Hormone assays on weekly blood samples (N = 180) from three female tigers indicated 16 cycles in two breeding seasons. Peak estradiol-17 beta levels were 46.7 +/- 6.0 pg/ml (N = 17) and interestrous concentrations were 8.7 +/- 0.66 pg/ml (N = 28) during the breeding season. Anestrous estradiol levels were 4.2 +/- 0.5 pg/ml (N = 70). The interestrous interval between estradiol peaks was 24.9 +/- 1.3 days (N = 9) with two outliers of 42 days. Serum progesterone concentrations from February to June were 1.2 +/- 0.15 ng/ml (N = 32), providing no evidence for ovulation or corpus luteum formation. Luteinizing hormone (LH) levels were 0.56 +/- 0.04 ng/ml (N = 180). Serum testosterone (r=0.71, P less than 0.001) and androstenedione levels (r=0.75, P less than 0.001) were correlated with estradiol during the breeding season. The duration of anestrus was 8 mo in two of these tigers. The interval was shortened in one tiger by exposure to a 16L:8D photoperiod. The Siberian tiger appears to be a polyestrous seasonal breeder and an induced ovulator whose breeding season may be synchronized by photoperiod.

Androstenedione↗
PubMed1976

A method for defining competency in Pediatrics.

In 1972 the American Board of Pediatrics (ABP) initiated studies leading to a report which identifies the important components of competency needed in the practice of pediatrics. The development of the report involved a group process engaging ABP board members and examiners. The outcome has been (a) the delineation of a process for establishing definitions of competency in a medical discipline; (b) the development of a framework for specifying the abilities needed to perform the tasks required of pediatricians; (c) an elaboration of samples of pediatric subjects to which these abilities and tasks are relevant; and (d) the development of a basis for choice of methods to use for purposes of certification.

Certification↗