Glycemic thresholds for activation of counterregulatory hormone and symptom responses in islet transplant recipients.

Context: In patients with type 1 diabetes and reduced awareness of hypoglycemia, the glycemic thresholds for activation of counterregulatory hormone and symptom responses to hypoglycemia are impaired, in part due to recurrent episodes of hypoglycemia. Islet transplantation can ameliorate occurrences of hypoglycemia in these patients.

Objective: The objective of the study was to determine whether the avoidance of hypoglycemia achieved through islet transplantation results in improved glycemic thresholds for counterregulatory responses.

Insulin sensitivity, glucose effectiveness, and free fatty acid dynamics after human islet transplantation for type 1 diabetes.

Context: Islet transplantation results in impaired insulin secretion, but whether defects in insulin sensitivity contribute to impaired glucose disposal after islet transplantation under modern immunosuppression is not known.

Objective: Our objective was to evaluate insulin sensitivity after islet transplantation performed under tacrolimus-based immunosuppression that used minimal steroids.

Setting: This study was conducted at the University of Pennsylvania General Clinical Research Center.

{beta}-Cell function following human islet transplantation for type 1 diabetes.

Islet transplantation can provide metabolic stability for patients with type 1 diabetes; however, more than one donor pancreas is usually required to achieve insulin independence. To evaluate possible mechanistic defects underlying impaired graft function, we studied five subjects at 3 months and four subjects at 12 months following intraportal islet transplantation who had received comparable islet equivalents per kilogram (12,601 +/- 1,732 vs. 14,384 +/- 2,379, respectively).

The multifunctional properties and characteristics of vitamin D-binding protein.

In recent years, our understanding of the many physiological, biochemical, and molecular functions and attributes of vitamin D-binding protein (DBP) has seen exciting and significant advances. Since its identification in 1959, many important functions of this abundant serum protein have been discovered. These range from the transport of vitamin D metabolites to possible roles in the immune system and host defense.

Transplacental drug delivery: gene and virus delivery to the trophoblast.

The development of successful strategies for delivering genes to the placenta may provide new opportunities for modifying trophoblast function in order to learn more about trophoblast physiology and to offer novel therapeutic options for complications of pregnancy that result from placental dysfunction. Replication-deficient recombinant viral vectors are useful vehicles for introducing genes into cells in vitro and in vivo. Recombinant adenovirus and herpes simplex virus vectors are unable to efficiently infect and transduce terminally differentiated trophoblastic cells.