Retreatability of a bioceramic root canal sealing material.

Introduction: The efficacy of retreatment techniques for BC Sealer (BCS) (Brasseler USA, Savannah, GA) removal has not yet been assessed. The purpose of this study was to evaluate the efficacy of solvent and rotary instrumentation in the removal of BCS when used in combination with gutta-percha (GP) as compared with AH Plus sealer (Dentsply, Tulsa, OK).

Methods: The mesiobuccal canals of 40 mandibular molars were instrumented and obturated with either GP/AH Plus with warm vertical compaction or GP/BCS using a single cone.

Localization of TrkC to Schwann cells and effects of neurotrophin-3 signaling at neuromuscular synapses.

Neurotrophins and their receptors, the Trks, are differentially expressed among the cell types that make up neuromuscular and other synapses, but the function and directionality of neurotrophin signaling at synapses are poorly understood. Here we demonstrate, via immunostaining, Western blotting, and RT-PCR analyses, that TrkC, the receptor for neurotrophin-3 (NT3), is expressed by mouse perisynaptic and myelinating Schwann cells from birth through adulthood and is unaltered after denervation. Analyses of transgenic mice in which the NT3 coding sequence is replaced by lacZ showed that NT3 is expressed in motor neurons and Schwann cells during perinatal development, but not in adult mice.

Neurobeachin is essential for neuromuscular synaptic transmission.

We report a random disruption in the mouse genome that resulted in lethal paralysis in homozygous newborns. The disruption blocked expression of neurobeachin, a protein containing a BEACH (beige and Chediak-Higashi) domain implicated in synaptic vesicle trafficking and an AKAP (A-kinase anchor protein) domain linked to localization of cAMP-dependent protein kinase activity. nbea-null mice demonstrated a complete block of evoked synaptic transmission at neuromuscular junctions, whereas nerve conduction, synaptic structure, and spontaneous synaptic vesicle release were completely normal.