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Biomedical subjects

R M Ferguson

Publications and source records attributed to R M Ferguson.

At least 109 records · Page 6Linked to original sources

Orthotopic liver transplantation with abdominal situs inversus and dextrocardia.

Anatomic anomalies may present technical difficulties during orthotopic liver transplantation. Abdominal situs inversus was considered a contraindication to liver transplantation. A successful liver transplant in a patient with both situs inversus and dextrocardia is described, along with a technical review.

Abnormalities, Multiple↗

Safety of simultaneous aortic reconstruction and renal transplantation.

Patients with aortic disease and end-stage renal failure who require both aortic reconstruction and renal transplantation (simultaneously or staged) pose a formidable clinical challenge. Traditionally, the performance of either one of these procedures has been viewed as a relative contraindication to the performance of the other. From 1978 to 1989, eight patients were referred to us with the combination of aortic disease and end-stage renal failure. Seven had aneurysmal disease and one had aorto-iliac occlusive disease. Five patients presented with their diseases sequentially and had two sequential operations, with a mean interval of 4 years between procedures. Three patients presented with their diseases simultaneously and underwent simultaneous aortic reconstruction and living related renal transplantation. All patients were followed up for a mean interval of 4.5 years. By life-table analysis, the 5-year renal graft survival was 100%, the primary aortic graft patency was 82%, and the secondary aortic graft patency was 100%. The only death in this series occurred 11 years after aortic reconstruction and 4 months after a renal transplantation and was due to overwhelming cytomegalovirus sepsis. There were no significant differences between the simultaneous and staged groups in terms of operative mortality, postoperative complications, transplant function, or aortic graft patency. From this experience, we conclude that: (1) patients who present simultaneously with aortic disease and end-stage renal failure can safely undergo simultaneous aortic reconstruction and renal transplantation; (2) patients who present with these two diseases sequentially can undergo a second reconstructive procedure with very low operative morbidity and mortality rates; (3) when these two procedures have been performed sequentially, the second procedure has not significantly altered the 30-day or 5-year results of the first procedure; and (4) the 30-day and 5-year results of each procedure have been excellent regardless of the temporal sequence in which they were performed.

Adult↗

Differential distribution of antigen-specific helper T cells and cytotoxic T cells after antigenic stimulation in vivo. A functional study using limiting dilution analysis.

We have developed modified limiting dilution analysis (LDA) techniques that distinguish in vivo Ag-stimulated murine helper T lymphocytes (HTL) and CTL from unstimulated precursor T cells, even those with the same Ag specificity. We refer to these cells that are detectable in the modified LDA as "Ag-conditioned" T cells (cHTL and cCTL). We have used the modified LDA techniques in conjunction with conventional LDA techniques (which enumerate all Ag-specific T cells) to evaluate the in vivo distribution of Ag-conditioned cHTL and cCTL following in vivo sensitization to alloantigens via sponge matrix or skin allografts. In general, we observed the following regarding the distribution of cHTL and cCTL: 1) Ag-conditioned HTL and CTL were detectable only after in vivo sensitization with alloantigen: 2) not all Ag-reactive T cells became conditioned T cells after in vivo Ag deposition; 3) the percentage of Ag-reactive T cells that converted to conditioned T cells after Ag deposition varied among different lymphoid compartments; 4) a high percentage of cHTL, but a low percentage of cCTL, accumulated in regional lymph nodes and spleen; 5) cHTL accumulated in peripheral blood, whereas cCTL did not; 6) Ag-conditioned cHTL were detectable in various lymphoid tissues for greater than 60 days following Ag deposition, whereas cCTL were detectable for only 14 to 20 days; and 7) unlike the other lymphoid sites, the site of Ag deposition accumulated a high percentage of both Ag-stimulated cHTL and cCTL. Furthermore, cHTL and cCTL appeared to reside in phenotypically distinct T cell subsets in that in vivo treatment with anti-L3T4 mAb abrogated the accumulation of HTL, but not CTL, at the site of Ag deposition. These data demonstrate differential compartmentalization of Ag-conditioned cHTL and cCTL subsequent to in vivo Ag deposition. The implications of these findings regarding the monitoring of in vivo immune responses are discussed.

Animals↗

Physiological and pharmacological stimulation of pancreatic islet hormone secretion in type I diabetic pancreas allograft recipients.

Successful heterotopic and denervated pancreas allograft transplantation (PAT) often results in normoglycemia and peripheral hyperinsulinemia in insulin-dependent (type I) diabetic recipients. The contribution of altered hepatic insulin extraction (HIE) to the resulting hyperinsulinemia in such patients remains uncertain. Furthermore, whether the denervated pancreas allografts exhibit beta-cell hyperresponsiveness to physiological and pharmacological stimulation is controversial. We evaluated beta-cell function and HIE after successful whole cadaveric PAT with systemic venous drainage in 13 type I diabetic patients before and after mixed-meal and intravenous glucose and glucagon administration. The results were compared with those of 5 nondiabetic patients with kidney transplantation only, who had native innervated pancreases with portal insulin delivery and were receiving an equivalent triple immunosuppressive therapy (cyclosporin, azathioprine, and prednisone), and 7 healthy control subjects with no family history of diabetes. After PAT, fasting and poststimulation serum glucose concentrations were normalized. PAT was associated with marked basal hyperinsulinemia (3- to 8-fold) as assessed by immunoreactive insulin (IRI) levels in type I diabetic patients (mean +/- SE 345 +/- 43 pM) compared with control subjects (43 +/- 14 pM) and nondiabetic kidney-transplantation patients (129 +/- 38 pM). After mixed-meal ingestion, the mean incremental integrated insulin area was similar in PAT patients (18 +/- 3 nM.min) compared with kidney-transplantation patients (20 +/- 4 nM.min) and healthy control subjects (21 +/- 3 nM.min). Basal serum C-peptide levels were significantly greater in PAT (1.72 +/- 0.13 nM) and kidney-transplantation (2.15 +/- 0.33 nM) patients than in healthy control subjects (0.50 +/- 0.10 nM; P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

The role of transplantation in diabetics with end-stage renal disease.

At our center, KPT is the treatment of choice for diabetics with ESRD who are not irreversibly disabled by their secondary complications of diabetes. Mortality, as a result of cardiovascular complications, has a significant impact on the outcome of patients in both the KPT and KTA groups. Metabolic complications are problematic in the early posttransplant period. Infectious complications are frequent but not life threatening in the combined recipients. Excellent graft outcome (pancreas and kidney) can be achieved in those patients selected to undergo the KPT procedure.

Adult↗