Percutaneous Aspiration and Sclerotherapy as Primary Management for a Symptomatic Benign Adrenal Cyst.

Adrenal cysts are a rare benign adrenal pathology. Although the majority of adrenal cysts are asymptomatic, large cysts may present with debilitating symptoms of mass effect. Surgical adrenalectomy or cyst fenestration has been the primary mode of management for such symptomatic cysts, but these interventions can be associated with excessive morbidity, particularly when considered in the context of benign disease.

Impact on AChR open channel noise by pore-peripheral salt bridge depends on voltage and divalent cations.

Mechanisms behind the fluctuations in the ionic current through single acetylcholine receptor (AChR) channels have remained elusive. In a recent study of muscle AChR we showed that mutation of a conserved intramembrane salt bridge in the β- and δ-subunits markedly increased fluctuations in the open channel current that extended from low to high frequency. Here, we show that extracellular divalent cations reduce the high-frequency fluctuations and increase the low-frequency fluctuations.

Stoichiometry-selective modulation of α4β2 nicotinic ACh receptors by divalent cations.

Background And Purpose: α4β2 nicotinic ACh receptors (nAChRs) comprise the most abundant class of nAChRs in the nervous system. They assemble in two stoichiometric forms, each exhibiting distinct functional and pharmacological signatures. However, whether one or both forms are modulated by calcium or magnesium has not been established.

Unmasking coupling between channel gating and ion permeation in the muscle nicotinic receptor.

Whether ion channel gating is independent of ion permeation has been an enduring, unresolved question. Here, applying single channel recording to the archetypal muscle nicotinic receptor, we unmask coupling between channel gating and ion permeation by structural perturbation of a conserved intramembrane salt bridge. A charge-neutralizing mutation suppresses channel gating, reduces unitary current amplitude, and increases fluctuations of the open channel current.

Structural basis for α-bungarotoxin insensitivity of neuronal nicotinic acetylcholine receptors.

The ten types of nicotinic acetylcholine receptor α-subunits show substantial sequence homology, yet some types confer high affinity for α-bungarotoxin, whereas others confer negligible affinity. Combining sequence alignments with structural data reveals three residues unique to α-toxin-refractory α-subunits that coalesce within the 3D structure of the α4β2 receptor and are predicted to fit between loops I and II of α-bungarotoxin. Mutating any one of these residues, Lys189, Ile196 or Lys153, to the α-toxin-permissive counterpart fails to confer α-bungarotoxin binding.