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Aims Short-QT syndrome (SQTS) is a recently recognized disorder associated with atrial fibrillation (AF) and sudden death due to ventricular arrhythmias. Mutations in several ion channel genes have been linked to SQTS; however, the mechanism remains unclear. This study describes a novel heterozygous gain-of-function mutation in the inward rectifier potassium channel gene, KCNJ2 , identified in SQTS. Methods and results We studied an 8-year-old girl with a markedly short-QT interval (QT = 172 ms, QTc = 194 ms) who suffered from paroxysmal AF. Mutational analysis identified a novel heterozygous KCNJ2 mutation, M301K. Functional assays displayed no Kir2.1 currents when M301K channels were expressed alone. However, co-expression of wild-type (WT) with M301K resulted in larger outward currents than the WT at more than −30 mV. These results suggest a gain-of-function type modulation due to decreased inward rectification. Furthermore, we analysed the functional significance of the amino acid charge at M301 (neutral) by changing the residue. As with M301K, in M301R (positive), the homozygous channels were non-functional, whereas the heterozygous channels demonstrated decreased inward rectification. Meanwhile, the currents recorded in M301A (neutral) showed normal inward rectification under both homo- and heterozygous conditions. Heterozygous overexpression of WT and M301K in neonatal rat ventricular myocytes exhibited markedly shorter action potential durations than the WT alone. Conclusion In this study, we identified a novel KCNJ2 gain-of-function mutation, M301K, associated with SQTS. Functional assays revealed no functional currents in the homozygous channels, whereas impaired inward rectification demonstrated under the heterozygous condition resulted in larger outward currents, which is a novel mechanism predisposing SQTS.

Background The predictive value of T-wave alternans (TWA) for lethal ventricular tachyarrhythmia in patients with left ventricular (LV) dysfunction is controversial. Also, long-term arrhythmia risk of patients ineligible for the TWA test is unknown. Methods This was a multicenter, prospective observational study of patients with LV ejection fraction ≤40% due to ischemic or non-ischemic cardiomyopathies, designed to evaluate the prognostic value of TWA for lethal ventricular tachyarrhythmia. The primary end point was a composite of sudden cardiac death, sustained rapid ventricular tachycardia (VT) or ventricular fibrillation (VF), and appropriate defibrillator therapy for rapid VT or VF. Results Among 453 patients enrolled in the study, 280 (62%) were eligible for the TWA test. TWA was negative in 82 patients (29%), who accounted for 18% of the total population. The median of follow-up was 36 months. The 3-year event-free rate for the primary end point was significantly higher in TWA-negative patients (97.0%) than in TWA non-negative patients (89.5%, P = 0.037) and those ineligible for the TWA test (84.4%, P = 0.003). Multivariable analysis identified both non-negative TWA [hazard ratio (HR) 4.43; 95% confidence interval (CI) 1.02–19.2; P = 0.047) and ineligibility for the TWA test (HR 6.89; 95% CI 1.59–29.9; P = 0.010) to be independent predictors of the primary end point. Conclusions TWA showed high negative predictive ability for lethal ventricular tachyarrhythmia in patients with LV dysfunction, although the TWA-negative patients accounted for only 18% of the entire population. Those ineligible for the TWA test had the highest risk for lethal ventricular tachyarrhythmia. Electronic supplementary material The online version of this article (doi:10.1007/s00392-011-0368-2) contains supplementary material, which is available to authorized users.

Background: Atrioventricular block (AVB) sometimes complicates QT prolongation and torsades de pointes (TdP). Methods and Results: The clinical and genetic background of 14 AVB patients (57±21 years, 13 females) who developed QT prolongation and TdP was analyzed. Electrophysiological characteristics of mutations were analyzed using heterologous expression in Chinese hamster ovary cells, together with computer simulation models. Every patient received a pacemaker or implantable cardioverter defibrillator; 3 patients had recurrence of TdP during follow-up because of pacing failure. Among the ECG parameters, QTc interval was prolonged to 561±76ms in the presence of AVB, but shortened to 495±42ms in the absence of AVB. Genetic screening for KCNQ1, KCNH2, SCN5A, KCNE1, and KCNE2 revealed four heterozygous missense mutations of KCNQ1 or KCNH2 in 4 patients (28.6%). Functional analyses showed that all mutations had loss of functions and various gating dysfunctions of IKs or IKr. Finally, action potential simulation based on the Luo-Rudy model demonstrated that most mutant channels induced bradycardia-related early afterdepolarizations. Conclusions: Incidental AVB, as a trigger of TdP, can manifest as clinical phenotypes of long QT syndrome (LQTS), and that some patients with AVB-induced TdP share a genetic background with those with congenital LQTS. (Circ J 2010; 74: 2562-2571)

Objectives This study describes a novel heterozygous gain-of-function mutation in the cardiac sodium (Na+) channel gene, SCN5A, identified in a Japanese family with lone atrial fibrillation (AF). Background SCN5A mutations have been associated with a variety of inherited arrhythmias, but the gain-of-function type modulation in SCN5A is associated with only 1 phenotype, long-QT syndrome type 3 (LQTS3). Methods We studied a Japanese family with autosomal dominant hereditary AF, multiple members of which showed an onset of AF or frequent premature atrial contractions at a young age. Results The 31-year-old proband received radiofrequency catheter ablation, during which time numerous ectopic firings and increased excitability throughout the right atrium were documented. Mutational analysis identified a novel missense mutation, M1875T, in SCN5A. Further investigations revealed the familial aggregation of this mutation in all of the affected individuals. Functional assays of the M1875T Na+ channels using a whole-cell patch-clamp demonstrated a distinct gain-of-function type modulation; a pronounced depolarized shift (+16.4 mV) in V1/2 of the voltage dependence of steady-state inactivation; and no persistent Na+ current, which is a defining mechanism of LQTS3. These biophysical features of the mutant channels are potentially associated with increased atrial excitability and normal QT interval in all of the affected individuals. Conclusions We identified a novel SCN5A mutation associated with familial AF. The mutant channels displayed a gain-of-function type modulation of cardiac Na+ channels, which is a novel mechanism predisposing to increased atrial excitability and familial AF. This is a new phenotype resulting from the SCN5A gain-of-function mutations and is distinct from LQTS3.

During the progression of heart failure (HF), phases of chronic compensation and acute decompensation alternate and the clinical status worsens during the acute phase. At the present time, few studies have focused their attention on the cycles of compensated and decompensated phases from the perspective of myocyte injury. We hypothesize that persistently increased serum cTn concentrations during chronic compensated HF identify patients likely to need multiple admissions to the hospital for management of acute cardiac decompensation, worsening their long-term prognosis by causing further myocyte injury during the acute phase. In patients with acute cardiac decompensation, myocyte injury observed within hours or days has a long-term predictive value, and the acute surge of myocyte injury occurring in the acutely decompensated phase might be an important therapeutic target from the perspective of myocyte preservation. Clinical trials that limit myocyte injury during acutely decompensated as well as during chronic compensated HF are warranted.

Since chronic heart failure (CHF) is a complex clinical syndrome, a single biomarker may not reflect all of its characteristics. In this study, the clinical significance of combination and serial measurement of biochemical markers of myocyte injury and myocardial load in patients with CHF from various etiologies was examined. Serum concentrations of cardiac troponin-T (cTnT) and plasma concentrations of brain natriuretic peptide (BNP) were measured simultaneously in 190 patients with CHF, including dilated cardiomyopathy (DCM) (n = 41), ischemic heart disease (n = 40), valvular or congenital disease (n = 53), hypertensive heart disease (n = 16), and hypertrophic cardiomyopathy (HCM) (n = 22). Serum cTnT concentrations ≥0.01 ng/ml were found in 46/190 patients (24%) at baseline (20% in DCM, 42% in ischemic heart disease, 21% in valvular or congenital disease, 43% in hypertensive heart disease, and 9% in HCM). Follow-up samples were obtained in 137 patients after a mean treatment period of 31.8 days. Although BNP decreased significantly in each disease category (P < 0.0001: DCM; P < 0.005: ischemic heart disease; P < 0.05: valvular or congenital disease; P < 0.005: hypertensive heart disease; P < 0.05: HCM), cTnT remained high in 36/137 patients (26%) (19% in DCM, 39% in ischemic heart disease, 25% in valvular or congenital disease, 38% in hypertensive heart disease, and 19% in HCM). The rate of adverse cardiac events was significantly higher in patients with high cTnT than in patients with low cTnT concentrations (P < 0.0001) (P < 0.05: DCM; P < 0.05: ischemic heart disease; P < 0.01: valvular or congenital disease). Multivariate analysis showed that both cTnT and BNP are independent prognostic factors, and patients with elevations of both cTnT and BNP had the poorest prognosis (P < 0.0001). In patients with CHF, the evolution and prognostic value of cTnT and BNP are different. The combined measurements of these markers should refine our understanding of the state and evolution of CHF.

OBJECTIVE: To apply the polymerase chain reaction (PCR) to detect clonality for potentially helping to establish a definitive diagnosis of lymphoma in cytologic material. STUDY DESIGN: In this retrospective study, Papanicolaou-stained cytologic smears and formalin-fixed, paraffin-embedded tissues from 17 cases of B-cell lymphoma were examined to investigate their clonality by a PCR technique using three different approaches (FR3, FR3A and FR2) for amplification of immunoglobulin heavy chain genes. Cytologic smears from 10 cases of non-neoplastic lymphoid tissues and T-cell lymphomas served as negative controls. RESULTS: Monoclonality was detected in 9 of 17 cases (53%) of B-cell lymphoma in cytologic smears as compared with 8 of 16 cases (50%) in tissue sections. Seminested PCRs (FR3A/FR2) were superior to the single PCR (FR3) in the detection rate (41% vs. 18%). Five of seven cases (71%) of marginal zone B-cell lymphomas showed monoclonality, whereas only 4 of 10 cases (40%) of diffuse large B-cell lymphomas did so. Monoclonality was demonstrated in none of the negative controls. CONCLUSIONS: Clonality detection in B-cell lymphomas by PCR using cytologic smears is specific and equal in sensitivity to that using formalin-fixed, paraffin-embedded tissues. The detection rate is especially excellent in marginal zone B-cell lymphoma, in which the cytologic diagnosis is particularly challenging. Combined seminested PCRs for FR3A and FR2 are advocated for a reliable assessment of clonality.

BACKGROUND: There are few descriptions of the cytologic features of subependymoma because this neoplasm is rare and most commonly encountered incidentally at autopsy. Here we report a surgical case of subependymoma occurring in the lateral ventricle and provide the first documentation of the crush cytologic features of this tumor. CASE: A 34-year-old woman was found to have a tumorous lesion in the right lateral ventricle. At surgery, a 2-cm-diameter tumor was detected in the anterior horn. Histologic examination during surgery revealed that the mass was composed of loose, fibrillary networks and clusters of nuclei showing mild pleomorphism. A number of microcystic formations were evident. Histologically, the neoplasm was considered benign-specifically, a subependymoma. Papanicolaou- or Giemsa-stained crush specimens and imprint smears were also prepared. The cytologic morphology was fundamentally the same as the histologic. In the crush specimens, microcystic formations were readily visible. Moreover, details of the cellular morphology were more easily recognized in the cytologic slides than in the frozen sections. CONCLUSION: Cytologic examination, particularly crush cytology, appears to be useful for the rapid diagnosis of subependymoma during surgery in combination with the examination of frozen histologic sections.

Background— Drugs with I Kr -blocking action cause secondary long-QT syndrome. Several cases have been associated with mutations of genes coding cardiac ion channels, but their frequency among patients affected by drug-induced long-QT syndrome (dLQTS) and the resultant molecular effects remain unknown. Methods and Results— Genetic testing was carried out for long-QT syndrome–related genes in 20 subjects with dLQTS and 176 subjects with congenital long-QT syndrome (cLQTS); electrophysiological characteristics of dLQTS-associated mutations were analyzed using a heterologous expression system with Chinese hamster ovary cells together with a computer simulation model. The positive mutation rate in dLQTS was similar to cLQTS (dLQTS versus cLQTS, 8 of 20 [40%] versus 91 of 176 [52%] subjects, P =0.32). The incidence of mutations was higher in patients with torsades de pointes induced by nonantiarrhythmic drugs than by antiarrhythmic drugs (antiarrhythmic versus others, 3 of 14 [21%] versus 5 of 6 [83%] subjects, P KCNQ1 and KCNH2 mutant channels showed complex gating defects without dominant negative effects or a relatively mild decreased current density. Drug sensitivity for mutant channels was similar to that of the wild-type channel. With the Luo-Rudy simulation model of action potentials, action potential durations of most mutant channels were between those of wild-type and cLQTS. Conclusions— dLQTS had a similar positive mutation rate compared with cLQTS, whereas the functional changes of these mutations identified in dLQTS were mild. When I Kr -blocking agents produce excessive QT prolongation (dLQTS), the underlying genetic background of the dLQTS subject should also be taken into consideration, as would be the case with cLQTS; dLQTS can be regarded as a latent form of long-QT syndrome.

Background: Mutations in the cardiac sodium (Na + ) channel gene, SCN5A , have been associated with a variety of inherited arrhythmias, but the gain-of-function type modulation in SCN5A is associated with only one phenotype, long-QT syndrome type3 (LQTS3). Methods and Results: We studied a Japanese family with autosomal dominant hereditary atrial fibrillation (AF), multiple members of which showed onset of AF or frequent premature atrial contractions at a young age. The 31-year-old proband received radio-frequency catheter ablation, during which time numerous ectopic firings and increased excitability throughout the right atrium were documented. Mutational analysis identified a novel missense mutation, M1875T, in SCN5A . Further investigations revealed the aggregation of this mutation in all of the affected individuals (Figure A ). Functional assays of the M1875T Na + channels using whole-cell patch-clamp demonstrated a distinct gain-of-function type modulation; a pronounced depolarized shift (+16.4 mV) in V 1/2 of the voltage dependence of steady-state inactivation (Figure B ), and no late Na + current which is a defining mechanism of LQTS3. These biophysical features of the mutant channels are potentially associated with increased atrial excitability and normal QT interval in all of the affected individuals. Conclusions: We identified a novel SCN5A mutation associated with familial AF. The mutant channels displayed a gain-of-function type modulation of cardiac Na + channels, which is a novel mechanism predisposing increased atrial excitability and familial AF. This is a new phenotype resulting from the SCN5A gain-of-function mutations and is distinct from LQTS3.

ObjectivesThis study aims to address whether D85N, a KCNE1 polymorphism, is a gene variant that causes long QT syndrome (LQTS) phenotype.BackgroundKCNE1 encodes the beta-subunit of cardiac voltage-gated K+channels and causes LQTS, which is characterized by the prolongation of the QT interval and torsades de pointes, a lethal arrhythmia. D85N, a KCNE1 polymorphism, is known to be a functional variant associated with drug-induced LQTS.MethodsIn order to elucidate the prevalence and clinical significance of this polymorphism, we performed genetic screening in 317 LQTS probands. For comparison, we examined its presence in 496 healthy control subjects. We also conducted biophysical assays for the D85N variant in mammalian cells.ResultsThe allele frequency for D85N carriers was 0.81% in healthy people. In contrast, among LQTS probands, there were 1 homozygous and 23 heterozygous carriers (allele frequency 3.9%). Seven of 23 heterozygous carriers had additional mutations in LQTS-related genes, and 3 female subjects had documented factors predisposing to the symptom. After excluding these probands, the D85N prevalence was significantly higher compared with control subjects (allele frequency 2.1%, p < 0.05). In a heterologous expression study with Chinese hamster ovarian cells, KCNE1-D85N was found to exert significant loss-of-function effects on both KCNQ1- and KCNH2-encoded channel currents.ConclusionsThe KCNE1-D85N polymorphism was significantly more frequent in our LQTS probands. The functional variant is a disease-causing gene variant of LQTS phenotype that functions by interacting with KCNH2 and KCNQ1. Since its allele frequency was ∼1% among control individuals, KCNE1-D85N may be a clinically important genetic variant.

眼科臨床上, クラミジア眼感染症は比較的頻度の高い疾患であるが, 細胞材料として提出される機会は多くなく, 細胞学的な報告も少ない. 今回われわれは, 臨床的にクラミジア結膜炎 (成人封入体結膜炎) が疑われ, 擦過細胞診を施行した症例を経験したので報告する. 症例は67歳, 男性. 結膜の充血ならびに分泌物増加を主訴に眼科を受診した. 2ヵ月前より配偶者にも同様の症状を認めている. 結膜擦過標本にて, 上皮細胞の細胞質内に微細な顆粒状あるいは網状小体が比較的高密度に集簇する像とともに, より粗大な顆粒状物質が集簇性に分布する像を認め, 両者ともに細胞学的に本感染細胞を疑った. 簡易固定染色 (Diff-Quik) 標本の脱色標本を用いて行ったクラミジア免疫染色にて, 前者は陰性であったが後者は陽性となり, 本症の確診に至った. クラミジア封入体は今回の症例のように典型的な星雲状封入体とは異なる像を呈する場合もあり, この場合には免疫染色が確定診断の一手法としてきわめて有用になると考えられた. 特に形態像と免疫染色像を対比できる点から, 臨床的に普及している蛍光抗体法や酵素免疫法などの抗原検出法にはない利点があると思われた.

Background Several pathologic processes can cause myocardial injury, which is followed by cardiac remodeling and congestive heart failure (CHF). Cardiac troponin T (cTnT), a specific and sensitive marker of myocardial injury, has been related to long-term outcome in patients with CHF, so the relationship between cTnT and other biochemical markers associated with the pathophysiology of CHF was investigated in the present study. Methods and Results Between February 2004 and December 2005, 145 consecutive hospitalized patients (mean left ventricular ejection fraction (LVEF) 31.6±0.9%) with CHF were divided into low (

Chronic heart failure (CHF) is a major cause of morbidity and mortality in industrialized countries. As societies are aging, efforts are directed toward early interventions to preserve quality of life as well as lower mortality. However, because of the paucity of specific symptoms, an early diagnosis and management of CHF might be challenging. In contrast, biochemical markers, which can be measured easily and without inter-observer variability, are now being carefully examined. Since CHF is a complex syndrome, a single biochemical marker cannot reflect its multiple manifestations. An ideal biochemical marker should 1) be a prognostic indicator, 2) reflect the therapeutic response, 3) be heart specific 4) be independent from other markers 5) reflect the pathophysiology of CHF, 6) assist in the early diagnosis of CHF, and 7) be reliable throughout the various phases of the syndrome, from before the onset of its clinical manifestations through its end-stage. This review summarizes our current understanding of biochemical markers of CHF based on its pathophysiology.

A 62-year-old woman was admitted to our hospital because of fever in August 2002. She had been treated under a diagnosis of Eisenmenger syndrome with ventricular septal defect since 1988. On admission, echocardiography and color Doppler echocardiography revealed a markedly enlarged pulmonary artery with a mobile flap, and dissection of the pulmonary artery. The origin of the fever could not be identified, and the fever subsided spontaneously without specific treatment. She had no chest pain, but fever might have been a sign of dissection in this patient. Longstanding pulmonary hypertension may cause dissection, which may lead to sudden death or pulmonary hemorrhage often seen in patients with Eisenmenger syndrome. Our patient was a rare survivor without serious bleeding complication.

To apply the polymerase chain reaction (PCR) to detect clonality for potentially helping to establish a definitive diagnosis of lymphoma in cytologic material.In this retrospective study, Papanicolaou-stained cytologic smears and formalin-fixed, paraffin-embedded tissues from 17 cases of B-cell lymphoma were examined to investigate their clonality by a PCR technique using three different approaches (FR3, FR3A and FR2) for amplification of immunoglobulin heavy chain genes. Cytologic smears from 10 cases of nonneoplastic lymphoid tissues and T-cell lymphomas served as negative controls.Monoclonality was detected in 9 of 17 cases (53%) of B-cell lymphoma in cytologic smears as compared with 8 of 16 cases (50%) in tissue sections. Semi-nested PCRs (FR3A/FR2) were superior to the single PCR (FR3) in the detection rate (41% vs. 18%). Five of seven cases (71%) of marginal zone B-cell lymphomas showed monoclonality, whereas only 4 of 10 cases (40%) of diffuse large B-cell lymphomas did so. Monoclonality was demonstrated in none of the negative controls.Clonality detection in B-cell lymphomas by PCR using cytologic smears is specific and equal in sensitivity to that using formalin-fixed, paraffin-embedded tissues. The detection rate is especially excellent in marginal zone B-cell lymphoma, in which the cytologic diagnosis is particularly challenging. Combined seminested PCRs for FR3A and FR2 are advocated for a reliable assessment of clonality.

Brugada syndrome is an inherited arrhythmic disorder, and mutations in the SCN5A gene, encoding cardiac sodium channels, are identified in approximately 15% of cases. A novel causative gene (glycerol-3 phosphate dehydrogenase-1 like; GPD1L) has been reported, and in the present study, 80 unrelated Japanese patients were screened for GPD1L mutations: 1 synonymous mutation was identified, as well as 1 intronic variant, both of which were absent in 220 control alleles. Additionally, a single-nucleotide polymorphism was detected in 4 patients. No non-synonymous mutations were found. GPD1L does not appear to be a major cause of Brugada syndrome in the Japanese population.

Andersen-Tawil syndrome (ATS) is a rare inherited disorder characterized by periodic paralysis, mild dysmorphic features, and QT or QU prolongation with ventricular arrhythmias in electrocardiograms (ECGs). Mutations of KCNJ2, encoding the human inward rectifying potassium channel Kir 2.1, have been identified in patients with ATS. We aimed to clarify the genotype-phenotype correlations in ATS patients. We screened 23 clinically diagnosed ATS patients from 13 unrelated Japanese families. Ten different forms of KCNJ2 mutations were identified in the 23 ATS patients included in this study. Their ECGs showed normal QTc intervals and abnormal U waves with QUc prolongation and a variety of ventricular arrhythmias. Especially, bidirectional ventricular tachycardia (VT) was observed in 13 of 23 patients (57%). Periodic paralysis was seen in 13 of 23 carriers (57%), dysmorphic features in 17 (74%), and seizures during infancy in 4 (17%). Functional assays for the two novel KCNJ2 mutations (c. 200G>A (p. R67Q) and c. 436G>A (p. G146S)) displayed no functional inward rectifying currents in a heterologous expression system and showed strong dominant negative effects when co-expressed with wild-type KCNJ2 channels (91% and 84% reduction at -50 mV respectively compared to wild-type alone). Immunocytochemistry and confocal imaging revealed normal trafficking for mutant channels. In our study, all of the clinically diagnosed ATS patients had KCNJ2 mutations and showed a high penetrance with regard to the typical cardiac phenotypes: predominant U wave and ventricular arrhythmias, typically bidirectional VT.

Background: Cardiac resynchronization(CRT) therapy by biventricular pacing(BiV) was reported recently as a therapy for patients with moderate to severe heart failure and ventricular asynchrony. In our country, specialized modality for BiV were available since april, 2004. The aim of our study is to investigate how BiV effects in Japanese patients with severe heart failure. Methods & Results: Fourteen patients (11 males, 3 females, mean age 70.6 +/- 8.8 years), in NYHA class III-IV, underwent CRT by BiV. Three (21.4%) had an ischemic heart disease, four (28.6%) had a previous pacemaker, and six (42.9%) were in chronic atrial fibrillation. One patient (7%) died of severe CHF and VF. One patient (7%) failed CRT because of absence of optimal coronary sinus location. The QRS width, NYHA functional class, left ventricular ejection-fraction (LVEF), left ventricular end-diastolic diameter (LVDd) were measured both before and 1 month after CRT. Comparison of these parameter between before and after CRT, QRS width (180.8 → 144.2 msec, p