An Uncommon Case of Ectopic Adrenocorticotropic Hormone Syndrome from a Pancreatic Neuroendocrine Tumor.

Ectopic adrenocorticotropic hormone (ACTH) syndrome is a rare form of Cushing disease (CD) with over-secretion of ACTH from nonpituitary tumor outside the adrenal or pituitary glands. Its diagnosis relies on both biochemical tests (high-dose dexamethasone suppression test, ACTH level, corticotropin-releasing hormone test) to confirm ACTH-dependent CD and image studies (CT or MRI of chest, abdomen, and/or pelvis) for source localization. We present a rare case of ectopic ACTH syndrome from a pancreatic neuroendocrine tumor (NET).

Effect of Repeated Glucagon Doses on Hepatic Glycogen in Type 1 Diabetes: Implications for a Bihormonal Closed-Loop System.

Objective: To evaluate subjects with type 1 diabetes for hepatic glycogen depletion after repeated doses of glucagon, simulating delivery in a bihormonal closed-loop system.

Research Design And Methods: Eleven adult subjects with type 1 diabetes participated. Subjects underwent estimation of hepatic glycogen using (13)C MRS.

Impact of hyperbaric oxygen on diabetic ulcers is unaffected by glycemic control.

Hyperbaric oxygen (HBO2) therapy is an established intervention for treating chronic diabetic lower extremity ulcers, but the impact of glycemic control on its efficacy has not been determined. The purpose of this study was to evaluate the impact of blood glucose control at initiation of HBO2 treatment on wound healing. Hemoglobin A1c (HbA1c) was measured at start of HBO2 therapy for 22 patients undergoing treatment of chronic lower extremity ulcers at two regional wound care centers.

A novel, stable, aqueous glucagon formulation using ferulic acid as an excipient.

Commercial glucagon is unstable due to aggregation and degradation. In closed-loop studies, it must be reconstituted frequently. For use in a portable pump for 3 days, a more stable preparation is required.

Quantification of the glycemic response to microdoses of subcutaneous glucagon at varying insulin levels.

Objective: Glucagon delivery in closed-loop control of type 1 diabetes is effective in minimizing hypoglycemia. However, high insulin concentration lowers the hyperglycemic effect of glucagon, and small doses of glucagon in this setting are ineffective. There are no studies clearly defining the relationship between insulin levels, subcutaneous glucagon, and blood glucose.

Biochemical stabilization of glucagon at alkaline pH.

Background: For patients with type 1 diabetes mellitus, a bihormonal artificial endocrine pancreas system utilizing glucagon and insulin has been found to stabilize glycemic control. However, commercially available formulations of glucagon cannot currently be used in such systems because of physical instability characterized by aggregation and chemical degradation. Storing glucagon at pH 10 blocks protein aggregation but results in chemical degradation.

Automated control of an adaptive bihormonal, dual-sensor artificial pancreas and evaluation during inpatient studies.

Automated control of blood glucose in patients with type-1 diabetes has not yet been fully implemented. The aim of this study was to design and clinically evaluate a system that integrates a control algorithm with off-the-shelf subcutaneous sensors and pumps to automate the delivery of the hormones glucagon and insulin in response to continuous glucose sensor measurements. The automated component of the system runs an adaptive proportional derivative control algorithm which determines hormone delivery rates based on the sensed glucose measurements and the meal announcements by the patient.

Mechanisms of glucagon degradation at alkaline pH.

Glucagon is unstable and undergoes degradation and aggregation in aqueous solution. For this reason, its use in portable pumps for closed loop management of diabetes is limited to very short periods. In this study, we sought to identify the degradation mechanisms and the bioactivity of specific degradation products.