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Biomedical subjects

D F Du Toit

Publications and source records attributed to D F Du Toit.

At least 37 records · Page 2Linked to original sources

Early postoperative pancreatic endocrine function after segmental and pancreaticoduodenal allotransplantation in nonimmunosuppressed primates.

In this study we evaluated the short-term hormonal effects of segmental and whole pancreatic allotransplantation on the glucose intolerance produced by hemipancreatectomy in the primate. In hemipancreatectomized animals without grafts the K-values were reduced to 0.6 +/- 0.05, plasma insulin increased from 27.5 +/- 2.5 to 63.5 +/- 6.3 microU/ml, and glucagon levels declined from 252 +/- 29.9 to 216.5 +/- 33.0 pg/ml. Hemipancreatectomized segmental allograft recipients rendered K-values of 0.79 +/- 0.05, plasma insulin increased from 19.98 +/- 3.43 to 66.0 +/- 17.03 microU/ml, and glucagon release declined from 395.6 +/- 63.0 to 226.2 +/- 37.6 pg/ml during IVGTT postoperatively. Hemipancreatectomized, pancreaticoduodenal allograft recipients rendered K-values of 0.82 +/- 0.1, results not significantly different from hemipancreatectomized or segmental allograft recipients. Plasma insulin increased from 29.5 +/- 4.0 to 186.0 +/- 25.0 microU/ml, and glucagon release declined from 1,087.0 +/- 31.6 to 656.0 +/- 12.7 pg/ml. In summary, segmental pancreatic allotransplantation could not, in the short-term, restore the reduced K-values and hypoinsulinaemia in hemipancreatectomized primates to that of normal, unstressed controls. Although K-values of hemipancreatectomized recipients were not significantly improved, whole pancreas transplantation resulted in improved insulin release and hyperglucagonaemia during IVGTT when compared to segmental allograft recipients. The unexpected findings of hypoinsulinaemia and hyperglucagonaemia in both transplant groups may only reflect a function of the stressed state of the animals in the immediate postoperative phase.

Animals↗

Diabetes in pancreatectomized baboons: a model for pancreatic transplantation studies.

This study was designed to assess plasma glucose levels (PLG) and insulin release in totally pancreatectomized baboons when challenged with intravenous glucose administration (IVGTT). Ten animals (Papio ursinus) were used and duodenectomy was intentionally avoided. The PLG at death was 18.0 +/- mmol/L, and the mean K-value within 3 days after pancreatectomy was 0.4% +/- 0.2%, indicating a significant impairment of glucose disappearance from the blood when compared to the control animals (P less than 0.01). Plasma insulin levels before and after stimulation with glucose were below the lowest level of insulin assay sensitivity. We conclude that in the primate, as in the dog, surgical pancreatectomy produced a reliable diabetic model, which is uniformly lethal if left untreated.

Animals↗

Primate endocrine function after pancreatico-duodenal-splenic allotransplantation.

In this study the endocrine function following intraperitoneal hetero- and orthotopic pancreatico-duodenal-splenic allotransplantation (PDS) in hemipancreatectomized, non-immune-suppressed chacma baboons was assessed. Significantly reduced K-values and insulin release together with glucose intolerance during IVGTT were observed in hemipancreatectomized recipients (HPS) without grafts. Orthotopic and heterotopic PDS transplantation improved the glucose intolerance of HPS recipients; orthotopically sited grafts rendering the best curves. Normal glucose tolerance was not achieved. Both orthotopic and heterotopic PDS transplantation rendered suboptimal insulin release during IVGTT; heterotopically draining grafts released significantly more insulin than orthotopic grafts. Hyperglucagonaemia during IVGTT was a constant feature in both groups, heterotopic grafts releasing the most glucagon during stimulation. C-peptide release was significantly lower in orthotopic grafts compared to normal animals or heterotopically drained insulin. It is concluded that glucose tolerance was not directly related to insulin or glucagon release in this study as orthotopic grafts rendered near-normal IVGTT curves in the presence of hypoinsulinaemia, hyperglucagonaemia, and reduced C-peptide values. The hormonal response after PDS transplantation was variable and the advantages of portal vs systemic insulin drainage remain to be defined.

Animals↗

Prolongation of segmental and pancreaticoduodenal allografts in the primate with total-lymphoid irradiation and cyclosporine.

The prolongation of segmental and pancreaticoduodenal allografts (PDA) by total lymphoid irradiation (TLI) and in combination with cyclosporine (CsA) was assessed in a well established total pancreatectomy, diabetic, primate transplantation model. Pancreatic transplantation was performed in 119 pancreatectomized baboons (Papio ursinus). Of a total of 109 allografts performed, 71 were segmental allografts (open duct drainage) and 38 PDA. Of 119 graft recipients, 10 received segmental pancreatic autografts. TLI and CsA administered separately to segmental allograft recipients resulted in modest allograft survival and indefinite graft survival was not observed. 8 of 17 (47%) segmental allograft recipients that received TLI and CsA had graft survival beyond 100 days, indicating highly significant pancreatic allograft survival. All long-term segmental allograft recipients were rendered normoglycemic (plasma glucose less than 8 mmol/L) by this immunosuppressive regimen. In contrast, poor results were observed in PDA recipients treated with TLI and CsA. Mean survival in 18 treated PDA recipients was 23.8 days, 8 survived longer than 20 days (44.4%), and 1 greater than 100 days (5.5%). Despite treatment, early rejection of the duodenum in PDA recipients frequently resulted in necrosis and perforation and contributed to a high morbidity and mortality. This study indicates that, in contrast to the significant prolongation of segmental allografts by TLI and CsA, poor immunosuppression was achieved by this regimen in PDA recipients and was associated with a high morbidity and mortality caused by early rejection of the duodenum.

Animals↗

Left paraduodenal hernia with acute abdominal symptoms. A case report.

A 22-year-old man with an incarcerated left paraduodenal hernia is described. Symptoms included nausea, vomiting, cramp-like abdominal pain and obstipation. A clinical diagnosis of mechanical small-intestinal obstruction was made on the history, examination, and abdominal radiographic findings. At laparotomy successful manual reduction was achieved, resection was not required and the patient made an uneventful recovery.

Adult↗

Endocrine function after immunosuppression of pancreatic allograft by ionizing irradiation in the primate.

The object of this preliminary study was to evaluate the endocrine function after heterotopic intraperitoneal segmental pancreatic allotransplantation with unligated duct in irradiated, totally pancreatectomized primates. All allograft recipients received, pre- and peroperative donor-specific blood transfusions and peroperative external irradiation from a linear accelerator; 200 rads was administered weekly and increased to a total dose of 1,500 rads. Pancreatic transplantation was performed between 2 and 6 weeks after completion of irradiation and preoperative blood transfusions. As previously reported, only minimal pancreatic allograft survival was achieved following preoperative irradiation. One recipient remained normoglycaemic for greater than 100 days after transplantation, the longest surviving pancreatic allograft recipient reported from this laboratory. Intravenous glucose tolerance test results in this recipient revealed normoglycaemia, reduced K-value, hypoinsulinaemia, normal glucagon response, reduced C-peptide values, and moderate glucose intolerance. Aortography and electron-microscopic examination of allograft biopsy tissue confirmed the presence of a functioning allograft.

Animals↗

Organ allotransplantation since the advent of cyclosporin.

Successful long-term organ transplantation has been made possible by the use of conventional immunosuppression. In contrast with transplantation of other organs, transplantation of the kidney has become an accepted successful form of therapy, 80% of patients being fully rehabilitated. However, complications of therapy are frequent and severe and include bone necrosis, cataract formation, infections and stunted growth in children. The discovery of the immunosuppressive properties of cyclosporin A (CYA) by Borel in 1976 offered new hope to recipients of hepatic, cardiac, pancreatic and heart-lung transplants, since rejection frequently resulted in death. Although the use of CYA has led to significant accomplishments, subsequent studies have documented deleterious side-effects including nephrotoxicity, hepatotoxicity, hirsutism, gingival hyperplasia, tremors and tumours. Yet despite the side-effects, CYA has proved to be a promising immunosuppressive agent for use in human organ transplantation and is at present being evaluated in transplant centres throughout the world.

Azathioprine↗

Recurrent pancreatitis after partial ileal bypass for hyperlipidaemia. A case report.

The case of a 28-year-old man with alcohol-induced bouts of recurrent acute pancreatitis after a partial ileal bypass performed for hyperlipidaemia is presented. Serial computed tomography proved valuable for assessing the resolution of the pancreatic mass. Peripheral parenteral hyperalimentation for 6 weeks had a beneficial effect on the course of the pancreatitis and proved to be useful for nutritional support.

Acute Disease↗

Gangrene of the hand and forearm after inadvertent intra-arterial injection of pyrazole. A case report.

A case of gangrene of the hand following inadvertent intra-arterial injection of a pyrazole derivative (Tomanol) is presented. Gangrene of the hand and superficial sloughing of the distal arm necessitated a forearm amputation. Because of the serious sequelae, precautions must be taken to avoid inadvertent intra-arterial injections and due consideration must be given to the anatomical variation of the brachial artery and its branches in the cubital fossa.

Adult↗

Prolongation of intraperitoneal segmental pancreatic allografts in primates receiving cyclosporin A.

In this study the efficacy of the new immunosuppressive agent, cyclosporin A (CYA), was examined in a model of segmental, intraperitoneal pancreatic allotransplantation with free duct drainage in totally pancreatectomized, outbred Chacma baboons. CYA, in doses of 25 to 50 mg/kg/day administered to recipients of heterotopic segmental (tail) allografts, produced a slight but significant prolongation of graft survival. CYA (25 to 85 mg/kg/day), administered orally after pancreatic transplantation gave daily serum trough levels of CYA that ranged from 300 to 600 ng/ml. Mean serum trough levels on the first postoperative day in recipients of 50 mg/kg/day were 121.1 +/- 61.6 ng/ml. There was a wide variation in daily serum trough levels exhibited between primates on the same daily oral dose, and there was no correlation between absolute serum trough levels of CYA and rejection. It is postulated that adequate serum CYA levels were not achieved by the oral administration of the drug to ensure allograft survival beyond 60 days in pancreatectomized recipients. Adverse effects occurred frequently and included anorexia, diarrhea, and tremors and were in direct proportion to the quantity of CYA required to prolong graft survival. Free duct drainage into the abdominal cavity frequently resulted in pancreatic ascites, which necessitated paracentesis, indicating that this method of duct drainage has limited clinical application. Although heterotopic autotransplantation or allotransplantation of the tail of the pancreas in the baboon was capable of maintaining normoglycemia in pancreatectomized baboons, glucose intolerance, reduced K values, and hypoinsulinemia were consistent findings during glucose tolerance tests, suggesting that an insufficient islet cell mass had been transplanted.

Animals↗

Ruptured abdominal aortic aneurysm and horseshoe kidney. A case report.

A patient with a ruptured abdominal aortic aneurysm associated with a horseshoe kidney is reported on. The treatment included aneurysmectomy and insertion of an aortic Dacron prosthesis without division of the isthmus of the kidney. The postoperative course was complicated by a stroke and mild renal failure, but the patient made excellent progress and was discharged from hospital 1 month after admission.

Aorta, Abdominal↗

Ruptured abdominal aortic aneurysm associated with an aorto-enteric fistula. A case report.

A patient with a ruptured abdominal aortic aneurysm and a primary aortoduodenal fistula is reported on. Treatment included aneurysmectomy, suture of the duodenal fistula, closure of the proximal and distal abdominal aortic stumps, and construction of an axillobifemoral bypass. The postoperative course was complicated by spinal cord ischaemia and pataplegia, Gram-negative septicaemia, secondary intra-abdominal haemorrhage and multiple abscess formation.

Aorta, Abdominal↗

High-output cardiac failure associated with an iliac artery aneurysm and arteriovenous fistula. A case report.

Rupture of an aneurysm into a major vein is an uncommon complication, and the resulting arteriovenous fistula frequently causes high-output cardiac failure as a presenting symptom. A patient with high-output cardiac failure refractory to conservative treatment and an aortic and left iliac artery aneurysm and associated arteriovenous fistula between the left common iliac artery and vein is presented. The fistula was confirmed by transfemoral arteriography. Successful resection of the aneurysm and closure of the fistula resulted in dramatic clinical improvement. Careful monitoring of cardiovascular function with a Swan-Ganz catheter, before, during and after operation contributed to a satisfactory result.

Aneurysm↗

Aneurysm of the splenic artery--a controversial entity.

The case of an asymptomatic, calcified, arteriosclerotic, intact splenic artery aneurysm in a 60-year-old woman is presented. The diagnosis was confirmed by selective coeliac arteriography and the aneurysm was successfully resected with preservation of the spleen.

Aneurysm↗

Intraperitoneal transplantation of vascularized segmental pancreatic autografts without duct ligation in the primate.

The aim of this study was to determine whether diabetes could be ameliorated in totally pancreatectomized baboons by heterotopic intraperitoneal autotransplantation of the tail of the pancreas with the duct unligated. Twenty-five baboons were made diabetic by total pancreatectomy. Six untreated pancreatectomized animals survived a median of 5 days with mean (+/- SE) plasma glucose levels of 18 +/- 1.37 mmol/L and mean (+/- SE) potassium (K) values of 0.36 +/- 0.02% before death. Successful autotransplantation of the tail of the pancreas rendered pancreatectomized baboons consistently normoglycemic. Intravenous glucose tolerance tests performed 6 weeks after transplantation in 12 autograft recipients showed glucose intolerance in 12 of 14 recipients, and K values were significantly reduced to 1.03 +/- 0.015% (P less than 0.05). The K value of 40 normal baboons was 2.18 +/- 0.15. Histologic examination of successfully transplanted autografts of 12 animals at 6 weeks showed islets with intact beta and alpha cells, atrophy of the exocrine pancreas, graft fibrosis, and a cellular infiltration of the mononuclear type. The addition of a distal arteriovenous fistula to the graft did not reduce the incidence of graft vessel thrombosis, and all five animals died of hemorrhagic pancreatitis and venous thrombosis within 24 hours of transplantation.

Animals↗

Unusual presentations of acute appendicitis in the neonate. A report of 2 cases.

Two neonates with acute appendicitis have been treated at the Paediatric Surgery Clinic, Tygerberg Hospital, during the past 6 months. One presented with red blood in the stool and had had persistent anorexia for 1 week. The second baby presented with a large tender swelling of the scrotum which was indistinguishable from a torsion of the testis or strangulation of an inguinal hernia. Both babies made an uneventful recovery.

Acute Disease↗