Biomedical subjects

Norman M Kenyon

Publications and source records attributed to Norman M Kenyon.

3 recordsLinked to original sources

PubMed2005

Omental anatomy of non-human primates.

The anatomy and physiology of the omentum provide optimum reconstructive characteristics and the omentum may be used as a free or pedicled autograft, but also as the receptor site for engraftment of glandular islets. Our purpose was the study of the omental anatomy of non-human primate (NHP), in order to determine an experimental model for pancreatic islets transplantation. Seventeen cadavers NHP (age range 4 years to 23 years) were utilised in this anatomical study. Both cynomolgus monkeys (macaca fascicularis) and baboons (papio hamadryas) were analysed. The animals were without known medical or anatomical abnormalities. We studied the morphology of the omentum, with an emphasis on arterial vascularisation. The omental anatomy of the NHP is very similar to that of humans. The main difference lies in the shape of the lesser sac, which has a complete caudal recess. The arterial vascularisation has a double origin. Based on the anastomosis between them and on the vascular density, the NHP omentum can be divided into four vascular areas. Our results demonstrate that one or two long pedicled flaps can be constructed from the omentum.

Animals↗

PubMed2004

Selective venous sampling in recurrent and persistent hyperparathyroidism: indication, technique, and results.

Between 1992 and 2002, 542 patients underwent a surgical treatment for hyperparathyroidism in our department. Twenty-three selective venous sampling procedures (SVS) were performed because of the failure of the other methods of diagnosis. These patients have recurrent or persistent hyperparathyroidism. Noninvasive methods of topographical diagnosis have failed or they have given contradictory results. In our experience, the surgeon needs a precise localization of the pathological glands in these difficult cases. In our series of SVS, specificity was 85.7% and sensitivity was 94.7%. Our results show that a high postoperative gradient of parathyroid hormone in the internal thoracic veins indicates an ectopic pathological gland in the thymus. A high gradient in a vertebral vein indicates a pathological superior parathyroid gland, usually in a retro-esophageal position.

Adult↗

PubMed2004

Islet allograft survival in nonhuman primates immunosuppressed with basiliximab, RAD, and FTY720.

OBJECTIVE: In a preclinical, nonhuman primate islet allotransplant model, the authors evaluated a novel immunosuppressive combination of basiliximab for induction and of RAD and FTY720 for maintenance. METHODS: Five ABO-compatible and mixed lymphocyte reactivity-mismatched streptozotocin-induced diabetic juvenile cynomolgus monkeys underwent transplantation intraportally with 48-hr cultured 10,000 islet equivalents per kilogram. Induction immunosuppression was with intravenous basiliximab (10 mg on postoperative days 0 and 4). Maintenance immunosuppression was with RAD (everolimus) (0.075 mg/kg per day administered subcutaneously) and FTY720 (0.3 mg/kg per day administered orally), both administered on day -2 through day 180 posttransplant. RESULTS: All five recipients tolerated their transplants and immunosuppressive therapy well, without adverse events or infectious complications. Insulin requirements pretransplant were 2.6 to 4.0 U/kg per day. All recipients became normoglycemic and insulin-independent posttransplant. Posttransplant serum C-peptide levels averaged 2.7 ng/mL (range, 0.6-6.2 ng/mL). Morning blood glucose levels ranged from less than 100 mg/dL to 150 mg/dL. Posttransplant acute C-peptide response to intravenous arginine averaged 1.3 ng/mL (range, 0.23-2.72 ng/mL). In one recipient with subtherapeutic RAD blood levels on day 7 posttransplant, exogenous insulin was resumed 100 days posttransplant; basal C-peptide levels remained positive in this recipient and averaged 2.6 ng/mL. The other four recipients remained insulin-independent for more than 6 months. CONCLUSIONS: This study provides preliminary evidence of the safety and efficacy of corticosteroid- and calcineurin inhibitor-free immunosuppression in a relevant preclinical transplant model. These findings provide a strong rationale for evaluating this nondiabetogenic regimen in a clinical trial of islet transplants in type 1 diabetic recipients.

Animals↗