Clinical and genetic diversity of nemaline myopathy from a single neuromuscular center in Korea.

Nemaline myopathy (NM), the most common of the congenital myopathies, is caused by various genetic mutations. In this study, we attempted to identify the causative mutations of NM and to reveal any specific genotype-phenotype relationship in Korean patients with this disease. We investigated the clinical features and genotypes in 15 pathologically diagnosed NM patients, using whole exome sequencing (WES) combined with targeted sequencing and array-based comparative genomic hybridization.

Identification of lysosomotropic compounds based on the distribution and size of lysosomes.

Lysosomal accumulation of drugs with their specific physicochemical properties is of key importance to drug distribution in the body. Several attempts have been made to treat various human diseases by employing the accumulation of lysosomal drugs, and many methods to identify lysosomal accumulation of drugs have been proposed. Among those, the use of high-content screening has increased tremendously because of improved efficiency and accuracy as well as the development of automatic image acquisition and analytical techniques.

Prevalence of anti-ganglioside antibodies and their clinical correlates with guillain-barré syndrome in Korea: a nationwide multicenter study.

Background And Purpose: No previous studies have investigated the relationship between various anti-ganglioside antibodies and the clinical characteristics of Guillain-Barré syndrome (GBS) in Korea. The aim of this study was to determine the prevalence and types of anti-ganglioside antibodies in Korean GBS patients, and to identify their clinical significance.

Methods: Serum was collected from patients during the acute phase of GBS at 20 university-based hospitals in Korea.

Prevalence and clinical characteristics of restless legs syndrome in diabetic peripheral neuropathy: comparison with chronic osteoarthritis.

Background: The prevalence of restless legs syndrome (RLS) in patients with peripheral neuropathy has been reported to be higher than that of the general population in some studies, which suggests an association between neuropathy and RLS, but not all studies show increased RLS with neuropathy. These differences may reflect adequacy of the diagnosis, effects of chronic pain complicating the diagnosis, or population differences. Moreover, if there is increased risk for RLS with neuropathy, it may reflect consequences of the chronic pain rather than other aspects of diabetes mellitus (DM).

Autonomic dysfunction in patients with orthostatic dizziness: validation of orthostatic grading scale and comparison of Valsalva maneuver and head-up tilt testing results.

Objectives: To investigate whether the Korean version of the Orthostatic Grading Scale (KOGS) is a reliable and valid measure for evaluating the severity of symptoms of orthostatic intolerance (OI) and to compare the diagnostic accuracy of Valsalva maneuver (VM) and head-up tilt test (HUTT) in identifying sympathetic adrenergic failure (SF).

Methods: A back-translation approach was used to develop the KOGS. One hundred seventy two patients with orthostatic dizziness (OD) as a presenting symptom of OI and 133 healthy controls were enrolled.

Comparison between clinical disabilities and electrophysiological values in Charcot-Marie-Tooth 1A patients with PMP22 duplication.

Background And Purpose: Charcot-Marie-Tooth disease (CMT) type 1A (CMT1A) is the demyelinating form of CMT that is significantly associated with PMP22 duplication. Some studies have found that the disease-related disabilities of these patients are correlated with their compound muscle action potentials (CMAPs), while others have suggested that they are related to the nerve conduction velocities. In the present study, we investigated the correlations between the disease-related disabilities and the electrophysiological values in a large cohort of Korean CMT1A patients.

Autosomal dominant nocturnal frontal lobe epilepsy and mild memory impairment associated with CHRNB2 mutation I312M in the neuronal nicotinic acetylcholine receptor.

Certain paroxysmal nocturnal behaviors have been established as features of nocturnal frontal lobe epilepsy (NFLE). Despite insight into its genetics, the majority of patients with NFLE are not linked to a known mutation and clinical diagnosis remains a challenge. We describe a family presenting with stereotyped nocturnal arousals from non-rapid eye movement sleep, bilateral hand posturing, and pelvic thrusting in the mother, but subtle motor activity in the daughter, and minimal or no epileptiform EEG discharges.

Uncoupling by (--)-epigallocatechin-3-gallate of ATP-sensitive potassium channels from phosphatidylinositol polyphosphates and ATP.

Of green tea catechins, (--)-epigallocatechin-3-gallate (EGCG) and (--)-epicatechin-3-gallate (ECG), but not (--)-epicatechin and (--)-epigallocatechin, inhibit the activity of ATP-sensitive potassium (K(ATP)) channels at tens of micromolar concentrations, ECG being three times more effective than EGCG. Further, we found that by using cloned beta cell-type K(ATP) channels, only EGCG at 1 microM, a readily achievable plasma concentration by oral intake in humans, but not other epicatechins, significantly blocked channel reactivation after ATP wash-out, suggesting that interaction of phosphatidylinositol polyphosphates (PIP) with the channel was impaired by EGCG. In addition, a 10-fold higher concentration of EGCG reduced the channel sensitivity to ATP, but not AMP and ADP.

Predicting a successful treatment in posterior canal benign paroxysmal positional vertigo.

Objective: To elucidate the characteristics and prognostic value of positioning nystagmus during the second position of the Epley maneuver (90 degrees contralateral head turn from the initial Hallpike maneuver).

Method: The Epley maneuver was performed in 126 patients with confirmed posterior canal benign paroxysmal positional vertigo (PC-BPPV). The characteristics of positioning nystagmus were investigated using video Frenzel goggles.

Muscular cell proliferative and protective effects of N-acetylcysteine by modulating activity of extracellular signal-regulated protein kinase.

N-acetylcysteine (NAC), an antioxidant and a precursor of glutathione, is currently in clinical use for various pathological conditions. No data is available as to the relationship between NAC and muscular cell proliferation or muscular degenerative disease. In this study, we assessed the effect of NAC on growth of L6 myoblasts, a rat skeletal muscle cell line, under normal or bupivacaine-treated condition.

Inhibitory modulation of ATP-sensitive potassium channels by gallate-ester moiety of (-)-epigallocatechin-3-gallate.

(-)-Epigallocatechin-3-gallate (EGCG), a major polyphenolic substance found in green tea, is well recognized to be beneficial for human health. However, it is still controversial as to what dose of this compound is indeed good for human health. Though some recent studies have interestingly reported various beneficial effects of EGCG in cell culture system, however, plasma levels of EGCG attainable by oral regular intake in humans are normally in nanomolar range.

Phenotypic variability in Kennedy's disease: implication of the early diagnostic features.

Objectives: The clinical diagnosis of Kennedy's disease (KD) is not easy when the typical manifestations are lacking, especially in early stage of the disease. In our study, we tried to identify the relative frequency of common clinical features and early symptoms in KD.

Method: Eighteen Korean patients with KD were included.

Taurine block of cloned ATP-sensitive K+ channels with different sulfonylurea receptor subunits expressed in Xenopus laevis oocytes.

Taurine has been found to inhibit ATP-sensitive K+ (KATP) channels in rat pancreatic beta-cells [Park et al., Biochem Pharmacol 2004;67:1089-1096] which could be due to its interaction with a benzamido-binding site on SUR1. In present study, we further evaluated the mechanism of taurine action on the KATP-channel inhibition, using cloned KATP-channels with different types of SUR subunit expressed in Xenopus laevis oocytes.

Taurine increases glucose sensitivity of UCP2-overexpressing beta-cells by ameliorating mitochondrial metabolism.

A low-taurine diet during fetal or early postnatal life causes abnormal pancreatic beta-cell development. Tissue and plasma taurine concentrations can also be low in diabetic patients. We examined the effect of taurine on impaired glucose responses in diabetic rat beta-cells adenovirally overexpressing uncoupling protein (UCP)2, which is upregulated in obesity-related type 2 diabetes.

Inhibition of ATP-sensitive K+ channels by taurine through a benzamido-binding site on sulfonylurea receptor 1.

ATP-sensitive potassium (K(ATP)) channels in pancreatic beta-cells comprise sulfonylurea receptor (SUR) 1 and inwardly-rectifying potassium channel (Kir) 6.2 subunits. We have evaluated the effect of intracellular taurine on K(ATP) channel activity in rat pancreatic beta-cells using the patch-clamp technique.

A Korean kindred with autosomal dominant nocturnal frontal lobe epilepsy and mental retardation.

Background: A Korean family had distinctive clinical and neuroimaging features and carried the same genetic mutation that was found in a previously described Japanese kindred with autosomal dominant nocturnal frontal lobe epilepsy.

Objective: To describe the first Korean family with autosomal dominant nocturnal frontal lobe epilepsy.

Methods: Members of a large family, including 9 affected individuals from 3 generations, underwent a comprehensive genetic, clinical, electroencephalographic, neuropsychological, and neuroimaging evaluation.

Giant intracranial varix arising from an arteriovenous fistula.

A case of a giant intracranial varix arising from an arteriovenous (AV) fistula is reported. This 16 year old boy presented with a sudden onset of headache and dizziness. The patient had suffered from intermittent seizure attacks since the age of 4.