Homogeneous human complex-type oligosaccharides in correctly folded intact glycoproteins: evaluation of oligosaccharide influence on protein folding, stability, and conformational properties.

The N-glycosylation of proteins is generated at the consensus sequence NXS/T (where X is any amino acid except proline) by the biosynthetic process, and occurs in the endoplasmic reticulum and Golgi apparatus. In order to investigate the influence of human complex-type oligosaccharides on counterpart protein conformation, crambin and ovomucoide, which consist of 46 and 56 amino acid residues, respectively, were selected for synthesis of model glycoproteins. These small glycoproteins were intentionally designed to be glycosylated at the α-helix (crambin: 8 position), β-sheet (crambin: 2 position) and loop position between the antiparallel β-sheets (ovomucoide: 28 position), and were synthesized by using a peptide-segment coupling strategy.

Molecular characterization and gene disruption of a novel zinc-finger protein, HIT-4, expressed in rodent brain.

To identify a novel regulatory factor involved in brain development or synaptic plasticity, we applied the differential display PCR method to mRNA samples from NMDA-stimulated and un-stimulated neocortical cultures. Among 64 cDNA clones isolated, eight clones were novel genes and one of them encodes a novel zinc-finger protein, HIT-4, which is 317 amino acid residues (36-38 kDa) in length and contains seven C2H2 zinc-finger motifs. Rat HIT-4 cDNA exhibits strong homology to human ZNF597 (57% amino acid identity and 72% homology) and identity to rat ZNF597 at the carboxyl region.

Preservation of renal function in response to cardiac resynchronization therapy.

Background: Cardiac resynchronization therapy (CRT) has recently been introduced as a new option for patients with severe heart failure, but its effect on renal function remains unclear.

Methods And Results: Twenty-three patients receiving CRT were studied. Responders were those who showed >0% increase in left ventricular ejection fraction after CRT by echocardiography.

Clinical characteristics, treatment, and outcome of tachycardia induced cardiomyopathy.

Tachycardia-induced cardiomyopathy is characterized by ventricular systolic dysfunction and congestive heart failure resulting from persistent or highly frequent tachyarrhythmias with uncontrolled heart rate. While reversible and often considered benign, few studies have examined the outcome of the disorder. The clinical characteristics, treatment, and long-term outcomes of 12 consecutive patients with tachycardia-induced cardiomyopathy (9 men, age, 51.

Chemical synthesis of a glycoprotein having an intact human complex-type sialyloligosaccharide under the Boc and Fmoc synthetic strategies.

The chemical synthesis of complex glycoproteins is an ongoing challenge in protein chemistry. We have examined the synthesis of a single glycoform of monocyte chemotactic protein-3 (MCP-3), a CC-chemokine that consists of 76 amino acids and one N-glycosylation site. A three-segment native chemical ligation strategy was employed using unprotected peptides and glycopeptide.

Effect of dl-sotalol on mortality and recurrence of ventricular tachyarrhythmias: ischemic compared to nonischemic cardiomyopathy.

Objective: We compared the effectiveness of sotalol on mortality and the recurrence of ventricular tachyarrhythmia (VTA) between idiopathic dilated cardiomyopathy (IDCM) and coronary artery disease (CAD).

Patients: Forty patients with spontaneous VTA and induced VTA associated with CAD (n = 23) and IDCM (n = 17) were studied. In all patients, sotalol was prescribed and an electrophysiologic study (EPS) was performed to evaluate its effect on the induction of VTA.

Comparison of conduction delay in the right ventricular outflow tract between Brugada syndrome and right ventricular cardiomyopathy: investigation of signal average ECG in the precordial leads.

Background: In both Brugada syndrome (BS) and arrhythmogenic right ventricular cardiomyopathy (ARVC), electrical abnormalities in the right ventricular outflow tract (RVOT) are important for arrhythmogenesis.

Objectives: The aim of this study was to compare conduction delay in the right ventricular in BS with that in ARVC using the signal-averaged electrocardiogram.

Methods: Twenty patients with BS (18 men and 2 women; 55 +/- 12 years old; 9 symptomatic and 11 asymptomatic) and eight patients with ARVC (six men and two women; 53 +/- 16 years old) were included.

Incidence and initial characteristics of pilsicainide-induced ventricular arrhythmias in patients with Brugada syndrome.

Background: In patients with Brugada syndrome, class I antiarrhythmic drugs can trigger ventricular arrhythmias (VA). The incidence and initial characteristics of VA that developed after pilsicainide was examined in 28 patients with Brugada-type electrocardiographic (ECG) abnormalities and with a positive response in the pilsicainide test. The clinical outcome was also compared between patients with and without pilsicainide-induced VA.

Bepridil for drug-refractory ventricular tachyarrhythmias.

Aims: To avoid frequent discharges of implantable cardioverter defibrillators, antiarrhythmic drugs may be needed in some patients with ventricular tachyarrhythmias. For ventricular tachyarrhythmias refractory to conventional antiarrhythmic drugs, we evaluated the efficacy of bepridil, a multiple ion-channel blocker.

Methods And Results: Sixteen patients with structural heart disease and ventricular tachyarrhythmias refractory to multiple antiarrhythmic drugs (4.

Over-expression of Kv1.5 in rat cardiomyocytes extremely shortens the duration of the action potential and causes rapid excitation.

Background: Genetically abnormal action potential duration (APD) can be a cause of arrhythmias that include long and short QT interval syndrome.

Purpose: The aim of this study was to evaluate the arrhythmogenic effect of short QT syndrome induced by the over-expression of Kv1.5 in rat.

Comparison of efficacy of sotalol and nifekalant for ventricular tachyarrhythmias.

Background: Suppression of implantable defibrillator discharges associated with ventricular tachyarrhythmia (VTA) has been reported for sotalol. This study aimed to investigate the efficacy of intravenous nifekalant hydrochloride in predicting the effects of oral sotalol.

Methods And Results: The present study included 14 patients who had sustained VTA associated with structural heart disease.

Ventricular tachycardia late after repair of congenital heart disease: efficacy of combination therapy with radiofrequency catheter ablation and class III antiarrhythmic agents and long-term outcome.

Objective: This study investigated the treatment of ventricular tachycardia (VT) after repair of tetralogy of Fallot or double outlet of the right ventricle.

Background: The ideal antiarrhythmic therapy for VT in patients after repair of congenital heart disease, especially without left ventricular dysfunction, has not yet been established.

Methods: Seven consecutive patients (2 women and 5 men) with stable monomorphic sustained VT were investigated.

Elimination of late potentials by quinidine in a patient with Brugada syndrome.

The beneficial effects of quinidine on ST-segment elevation, inducible ventricular tachyarrhythmias, and episodes of ventricular tachyarrhythmia have been reported in Brugada syndrome. This is the first report describing quinidine-induced elimination of the late potential, which is considered one of the parameters for an arrhythmic event, in a patient with Brugada syndrome.

Nifekalant hydrochloride suppresses severe electrical storm in patients with malignant ventricular tachyarrhythmias.

Background: Some patients with an implantable cardioverter-defibrillator (ICD) suffer from burst of inappropriate multiple discharges (severe electrical storm), and because the current therapeutic options are limited, the effect of nifekalant hydrochloride, a new class III drug, on severe electrical storm was investigated in the present study.

Methods And Results: Ninety-one consecutive patients treated with ICD were included in the study (M 70; mean age 58 years; left ventricular ejection fraction 45+/-15%). Severe electrical storm was defined as more than 10 ICD discharges within 1 h.

Inappropriate discharges of intravenous implantable cardioverter defibrillators owing to lead failure.

We describe here the case of a 58-year-old female patient who experienced inappropriate shocks from her implantable cardioverter-defibrillator (ICD). Stored electrograms from her ICD showed high frequency noise preceding the shock. Although the pacing threshold was normal and lead fracture was not found in chest X-rays, pacing lead impedance decreased to 480 omega.

Similarities between Brugada syndrome and ischemia-induced ST-segment elevation. Clinical correlation and synergy.

Vasospastic angina (VSA) and Brugada syndrome (BS) are classified into different categories of cardiac disease, but both can be causes of sudden cardiac death from ventricular fibrillation (VF). The coexistence of VSA and BS in the same patient is possible, and this raises several questions: (1) what is the incidence of the coexistence of BS and VSA in the same patient? (2) is susceptibility to VF enhanced by the coexistence of the 2 diseases? and (3) is there any possibility of Ca-antagonists being used for the treatment of VSA-aggravated BS? In our institution, VSA coexisted in 5 of the 38 patients with BS (13.1%).

Variable electrocardiographic effects of short-term quinidine sulfate administration in Brugada syndrome.

Quinidine, a class I antiarrhythmic agent with blocking property of transient outward current, is a possible candidate for the suppression of ventricular fibrillation in patients with Brugada syndrome; although there is a concern that its ability to these effects may be proarrhythmic. Therefore, we evaluated the effect of quinidine sulfate on ST-segment elevation in Brugada syndrome. In 8 patients with Brugada syndrome, the magnitude of ST-elevation at the J-point (ST(J)), and the ST-segment configuration in leads V1-V3, were compared before and on day 2 after the initiation of quinidine administration.

Potential candidates for cardiac resynchronization therapy in Japanese patients with idiopathic dilated cardiomyopathy--a Niigata multicenter study of DCM--.

Background: The purpose of this study was to assess the candidates suitable for cardiac resynchronization therapy (CRT) and to examine the significance of the QRS duration in Japanese patients with idiopathic dilated cardiomyopathy (DCM).

Methods And Results: The study population consisted of 357 patients. The selection criteria for candidates suitable for CRT were QRS duration =130 ms, left ventricular ejection fraction (LVEF) =35% and New York Heart Association (NYHA) functional class III or IV by ACC/AHA/NASPE 2002 guidelines.

Postprandial variations in ST-segment in a patient with Brugada syndrome and partial gastrectomy.

A 74-year-old man with a history of partial gastrectomy presented with an electrocardiogram consistent with Brugada syndrome and marked meal related fluctuations in the ST segment. ST-segment elevation was prominently attenuated at 30 minutes and increased at 120 minutes after meals. Analysis of heart rate variability revealed a relationship between postprandial heightened parasympathetic activity and increase in Brugada-type ECG abnormality.

Microdislodgment of ventricular pacing lead undetectable during rapid pacing one year after implantation.

A 71-year-old woman had undergone valvular heart surgery in 1981, and implantation of a permanent ventricular pacemaker for ventricular pauses during atrial fibrillation in 2001. One year after pacemaker implantation, she complained of faintness. When pacing at 100 beats/min the pacemaker functioned properly.

Suppression of electrical storm by biventricular pacing in a patient with idiopathic dilated cardiomyopathy and ventricular tachycardia.

This study presents a patient with idiopathic dilated cardiomyopathy who had suffered from multiple ICD shocks. Amiodarone and a beta-blocker failed to suppress ventricular tachycardia. His ECG showed a very wide QRS complex with an intraventricular conduction delay, so biventricular (BV) pacing was attempted.