[Possibilities for residual hearing preservation with Nucleus CI532 Slim Modiolar electrode array. Case report].

During the rehabilitation of hearing-impaired patients, the preservation of residual acoustic hearing following cochlear implantation by minimizing the implantation trauma allows for improved hearing performance. To achieve this, minimally invasive, soft surgery methods and thinner, atraumatic electrodes were required. In our present study, we reported a case where Cochlear® Nucleus CI532 Slim Modiolar electrode was implanted in a patient with residual hearing.

Altered expression of genes for Kir ion channels in dilated cardiomyopathy.

Dilated cardiomyopathy (DCM) is a multifactorial disease characterized by left ventricular dilation that is associated with systolic dysfunction and increased action potential duration. The Kir2.x K⁺ channels (encoded by KCNJ genes) regulate the inward rectifier current (IK1) contributing to the final repolarization in cardiac muscle.

Ionic mechanisms limiting cardiac repolarization reserve in humans compared to dogs.

The species-specific determinants of repolarization are poorly understood. This study compared the contribution of various currents to cardiac repolarization in canine and human ventricle. Conventional microelectrode, whole-cell patch-clamp, molecular biological and mathematical modelling techniques were used.

Structure, function and clinical relevance of the cardiac conduction system, including the atrioventricular ring and outflow tract tissues.

It is now over 100years since the discovery of the cardiac conduction system, consisting of three main parts, the sinus node, the atrioventricular node and the His-Purkinje system. The system is vital for the initiation and coordination of the heartbeat. Over the last decade, immense strides have been made in our understanding of the cardiac conduction system and these recent developments are reviewed here.

Gender-related differences in ion-channel and transporter subunit expression in non-diseased human hearts.

Gender-related differences in ventricular electrophysiology are known to be important determinants of human arrhythmic risk, but the underlying molecular basis is poorly understood. The present work aims to provide the first detailed analysis of gender-related cardiac ion-channel gene-distribution, based on samples from non-diseased human hearts. By using a high-throughput quantitative approach, we investigated at a genome-scale the expression of 79 genes encoding ion-channel and transporter subunits in epicardial and endocardial tissue samples from non-diseased transplant donors (10 males, 10 females).

Does small-conductance calcium-activated potassium channel contribute to cardiac repolarization?

Small-conductance calcium-activated potassium channels (SK channels) have a significant role in neurons. Since they directly integrate calcium handling with repolarization, in heart their role would be particularly important. However, their contribution to cardiac repolarization is still unclear.

Transcriptional profiling of ion channel genes in Brugada syndrome and other right ventricular arrhythmogenic diseases.

Aims: Brugada syndrome is an inherited sudden-death arrhythmia syndrome. Na(+)-current dysfunction is central, but mutations in the SCN5A gene (encoding the cardiac Na(+)-channel Nav1.5) are present in only 20% of probands.

Zerumbone exerts a beneficial effect on inflammatory parameters of cholecystokinin octapeptide-induced experimental pancreatitis but fails to improve histology.

Objective: Our experiments were designed to investigate the effects of zerumbone pretreatment on cholecystokinin octapeptide (CCK-8)-induced acute pancreatitis in rats.

Methods: Male Wistar rats weighing 240 to 280 g were divided into a control group, a group treated with CCK-8, a group receiving 20 mg/kg zerumbone before CCK-8 administration, and a group treated with zerumbone only.

Results: The serum amylase and lipase activities and the pancreatic weight-body weight ratio were significantly reduced by zerumbone pretreatment, but the drug failed to influence the histological parameters of pancreatitis.

Regional and tissue specific transcript signatures of ion channel genes in the non-diseased human heart.

The various cardiac regions have specific action potential properties appropriate to their electrical specialization, resulting from a specific pattern of ion-channel functional expression. The present study addressed regionally defined differential ion-channel expression in the non-diseased human heart with a genomic approach. High-throughput real-time RT-PCR was used to quantify the expression patterns of 79 ion-channel subunit transcripts and related genes in atria, ventricular epicardium and endocardium, and Purkinje fibres isolated from 15 non-diseased human donor hearts.

Activation of the poly(ADP-ribose) polymerase pathway in human heart failure.

Poly(ADP-ribose) polymerase (PARP) activation has been implicated in the pathogenesis of acute and chronic myocardial dysfunction and heart failure. The goal of the present study was to investigate PARP activation in human heart failure, and to correlate PARP activation with various indices of apoptosis and oxidative and nitrosative stress in healthy (donor) and failing (NYHA class III-IV) human heart tissue samples. Higher levels of oxidized protein end-products were found in failing hearts compared with donor heart samples.

In vitro molecular interactions and distribution of KCNE family with KCNQ1 in the human heart.

Objective: The voltage-gated K+ channel KCNQ1 associates with the small KCNE1 beta subunit to underlie the IKs repolarizing current in the heart. Based on sequence homology, the KCNE family is recognized to comprise five members. Controversial data have indicated their participation in several K+ channel protein complexes, including KCNQ1.