Artificial Synapse: Spatiotemporal Heterogeneities in Dopamine Electrochemistry at a Carbon Fiber Ultramicroelectrode.

An artificial synapse is developed that mimics ultramicroelectrode (UME) amperometric detection of single cell exocytosis. It comprises the nanopipette of a scanning ion conductance microscope (SICM), which delivers rapid pulses of neurotransmitter (dopamine) locally and on demand at >1000 defined locations of a carbon fiber (CF) UME in each experiment. Analysis of the resulting UME current-space-time data reveals spatiotemporal heterogeneous electrode activity on the nanoscale and submillisecond time scale for dopamine electrooxidation at typical UME detection potentials.

Maximal venous outflow velocity: an index for iliac vein obstruction.

Leg swelling is a common cause for vascular surgical evaluation, and iliocaval obstruction due to May-Thurner syndrome (MTS) can be difficult to diagnose. Physical examination and planar radiographic imaging give anatomic information but may miss the fundamental pathophysiology of MTS. Similarly, duplex ultrasonographic examination of the legs gives little information about central impedance of venous return above the inguinal ligament.

Endocrine response after gamma knife-based stereotactic radiosurgery for secretory pituitary adenoma.

Purpose: To examine treatment outcomes of Gamma Knife-based stereotactic radiosurgery (GK-based SRS) for secretory pituitary adenomas.

Materials And Methods: 25 patients were treated with GK-based SRS for secretory pituitary adenomas with >or=12 months of follow-up.

Results: For prolactinomas, 2 of 4 patients (50%) showed normalization of serum prolactin at a mean time of 18 months.

Acromegaly caused by a growth hormone-releasing hormone-secreting carcinoid tumor: case report.

Objective And Importance: We describe a patient with acromegaly and pituitary hyperplasia secondary to a growth hormone-releasing hormone-secreting gastrointestinal carcinoid tumor. This case report illustrates the importance of including this rare clinical syndrome in the differential diagnosis of acromegaly for patients with suspected or known neuroendocrine tumors.

Clinical Presentation: A 19-year-old, Asian-American, male patient with a 2-year history of a nonresectable, metastatic, intestinal carcinoid tumor presented with complaints of headaches, arthralgias, sweats, and changing features.