Novel Single-Staged Posterior Retropleural Approach with Thoracoscopic Guidance for Resection of a Thoracic Dumbbell Schwannoma.

Dumbbell spinal cord tumors are infrequent pathologic entities. The optimal approach to safe surgical resection is ill-defined and must often be individualized. This is assisted with multiple tumor classification systems.

SAP97 regulates Kir2.3 channels by multiple mechanisms.

We examined the impact of coexpressing the inwardly rectifying potassium channel, Kir2.3, with the scaffolding protein, synapse-associated protein (SAP) 97, and determined that coexpression of these proteins caused an approximately twofold increase in current density. A combination of techniques was used to determine if the SAP97-induced increase in Kir2.

Amino terminal glutamate residues confer spermine sensitivity and affect voltage gating and channel conductance of rat connexin40 gap junctions.

Connexin40 (Cx40) contains a specific binding site for spermine (affinity approximately 100 microm) whereas connexin43 (Cx43) is unaffected by identical concentrations of intracellular spermine. Replacement of two unique glutamate residues, E9 and E13, from the cytoplasmic amino terminal domain of Cx40 with the corresponding lysine residues from Cx43 eliminated the block by 2 mm spermine, reduced the transjunctional voltage (V(j)) gating sensitivity, and reduced the unitary conductance of this Cx40E9,13K gap junction channel protein. The single point mutations, Cx40E9K and Cx40E13K, predominantly affected the residual conductance state (G(min)) and V(j) gating properties, respectively.

Regulation of connexin43 gap junctional conductance by ventricular action potentials.

Transjunctional voltage regulates cardiac gap junctional conductance, but the kinetics of inactivation were considered too slow to affect cardiac action potential propagation. Connexin43 (Cx43) is abundantly expressed in the atrial and ventricular myocardium and the rapid ventricular conduction tissues (ie, His-Purkinje system) of the mammalian heart and is important to conduction through these cardiac tissues. The kinetics of Cx43 voltage gating were examined at peak action potential voltages using simulated ventricular myocardial action potential waveforms or pulse protocols exceeding 100-mV transjunctional potentials.