Modified Ca(v)1.4 expression in the Cacna1f(nob2) mouse due to alternative splicing of an ETn inserted in exon 2.

The Cacna1f(nob2) mouse is reported to be a naturally occurring null mutation for the Ca(v)1.4 calcium channel gene and the phenotype of this mouse is not identical to that of the targeted gene knockout model. We found two mRNA species in the Cacna1f(nob2) mouse: approximately 90% of the mRNA represents a transcript with an in-frame stop codon within exon 2 of CACNA1F, while approximately 10% of the mRNA represents a transcript in which alternative splicing within the ETn element has removed the stop codon.

The Ca(v)1.4 calcium channel: more than meets the eye.

Ca(v)1.4 channels are the latest calcium channels to be described in the literature. Originally identified in 1997 from the human genome project, several reports have since been published describing mutations in the CACNA1F gene encoding Ca(v)1.

Scanning mutagenesis reveals a role for serine 189 of the heterotrimeric G-protein beta 1 subunit in the inhibition of N-type calcium channels.

Direct interactions between the presynaptic N-type calcium channel and the beta subunit of the heterotrimeric G-protein complex cause voltage-dependent inhibition of N-type channel activity, crucially influencing neurotransmitter release and contributing to analgesia caused by opioid drugs. Previous work using chimeras of the G-protein beta subtypes Gbeta1 and Gbeta5 identified two 20-amino acid stretches of structurally contiguous residues on the Gbeta1 subunit as critical for inhibition of the N-type channel. To identify key modulation determinants within these two structural regions, we performed scanning mutagenesis in which individual residues of the Gbeta1 subunit were replaced by corresponding Gbeta5 residues.

Functional analysis of Ca3.2 T-type calcium channel mutations linked to childhood absence epilepsy.

Purpose: Childhood absence epilepsy (CAE) is an idiopathic form of seizure disorder that is believed to have a genetic basis.

Methods: We examined the biophysical consequences of seven mutations in the Ca(v)3.2 T-type calcium channel gene linked to CAE.

ORL1 receptor-mediated internalization of N-type calcium channels.

The inhibition of N-type calcium channels by opioid receptor like receptor 1 (ORL1) is a key mechanism for controlling the transmission of nociceptive signals. We recently reported that signaling complexes consisting of ORL1 receptors and N-type channels mediate a tonic inhibition of calcium entry. Here we show that prolonged ( approximately 30 min) exposure of ORL1 receptors to their agonist nociceptin triggers an internalization of these signaling complexes into vesicular compartments.

Hereditary multiple intestinal atresia: thirty years later.

Background: Hereditary multiple intestinal atresia (HMIA) is an unusual form of intestinal atresia with a presumed autosomal recessive mode of inheritance. The aim of this study was to review the authors' experience with this disease, 30 years after its first description.

Methods: All cases of HMIA treated at the authors' institution were reviewed with a particular focus on presence of close consanguinity in the families, prenatal diagnosis, radiologic and surgical findings, pathology report, and outcome.

A single Gbeta subunit locus controls cross-talk between protein kinase C and G protein regulation of N-type calcium channels.

The modulation of N-type calcium channels is a key factor in the control of neurotransmitter release. Whereas N-type channels are inhibited by Gbetagamma subunits in a G protein beta-isoform-dependent manner, channel activity is typically stimulated by activation of protein kinase C (PKC). In addition, there is cross-talk among these pathways, such that PKC-dependent phosphorylation of the Gbetagamma target site on the N-type channel antagonizes subsequent G protein inhibition, albeit only for Gbeta(1)-mediated responses.

Laparoscopic appendectomy in children: A favorable alternative in simple and complicated appendicitis.

Background/purpose: The laparoscopic treatment of pediatric appendicitis remains controversial, particularly in complicated cases (gangrene and perforation). This study evaluates outcomes of open (OA) and laparoscopic appendectomy (LA).

Methods: The 391 cases of pediatric appendectomy performed between January 1998 and January 2001 were reviewed for age, sex, weight, type and length of intervention, operative description, antimicrobial therapy, analgesia, complications, length of hospitalization, and histopathology.