Twenty-Four Month Results of Intravitreal Ranibizumab for Macular Edema after Branch Retinal Vein Occlusion: Visual Outcomes and Resolution of Macular Edema.

Purpose: To report 24-month results after one intravitreal ranibizumab (IVR) injection followed by pro re nata (PRN) dosing for macular edema (ME) after branch retinal vein occlusion (BRVO).Methods: Eyes with BRVO met the followings were included: 77 letters or less best-corrected visual acuity (BCVA) (Early Treatment Diabetic Retinopathy Study [ETDRS] score) and central retinal thickness (CRT) of 250 µm or more. IVR injection was performed followed by a PRN regimen. The retreatment criteria included visual loss of five or more ETDRS letters compared with the previous visit, 250 µm or more of CRT, or presence of residual or recurrent ME including the parafoveal lesions. The primary outcome measures were the BCVA changes at month 12 and month 24 from baseline, and the secondary outcomes were changes in CRT, resolution of ME, the number of IVR injections, and changes of nonperfused areas (NPAs).Results: Twenty eyes of 20 patients (5 men, 15 women; mean age, 68.2 years) were enrolled. The mean BCVAs (ETDRS letters) at baseline, month 12, and month 24 were 62.0, 80.2, and 80.9, respectively. The mean ETDRS letters gains were 18.3 and 19.0 at month 12 and month 24, respectively. The percentages of patients with Snellen equivalent BCVAs of 20/20 or better at month 12 and month 24 were 75% and 70%, respectively. The mean CRTs at baseline, month 12, and month 24 were 480, 252, and 272 µm, respectively. Forty percent of all eyes had complete resolution of ME. The mean number of IVR injections was 8.3 times, which gradually decreased over time. The NPA change in either Zone 1 or Zone 2 was not significant during the follow-up. No adverse side effects were observed.Conclusion: IVR injection followed by a PRN regimen provided pretty good visual outcomes at month 24.

Macular hole and serous pigment epithelial detachment in bilateral acquired vitelliform lesions.

PURPOSE: Acquired vitelliform lesions (AVLs) are associated with age-related macular degeneration and other variable macular disorders. AVLs often lead to outer retinal atrophy, sometimes accompanying a macular hole and choroidal neovascularization. The purpose of this study was to report a rare case with bilateral AVLs, in which one eye had accompanied a macular hole and the second eye a serous pigment epithelial detachment (sPED). OBSERVATIONS: A 66-year-old woman complained of bilateral metamorphopsia. AVLs were observed in the right eye and a flat sPED in the left eye. The best-corrected visual acuity (BCVA) was 20/17 in both eyes. Fluorescein angiography revealed local leakage in the right eye and pattern dystrophy-like hypofluorescence in both eyes. The sPED progressed with AVLs in the left eye and was treated with a combination therapy of intravitreal aflibercept, a sub-Tenon's injection of triamcinolone acetonide, and photodynamic therapy (IVA/STTA/PDT), which successfully flattened the sPED and sustained good vision for 4 years. The right eye was treated with intravitreal ranibizumab and tissue plasminogen activator, which enhanced absorption of the vitelliform material. However, 14 months later, a macular hole with typical metamorphopsia formed above a subretinal fibrotic scar at the vitelliruptive stage. Although pars plana vitrectomy closed the macular hole, enlargement of the outer retinal atrophy worsened the BCVA to 20/100. CONCLUSIONS AND IMPORTANCE: We successfully treated one eye with a sPED with AVLs using the combination therapy of IVA/STTA/PDT, while the second eye with a macular hole secondary to AVLs ultimately developed outer retinal atrophy with visual loss.

Six-month results of intravitreal ranibizumab for macular edema after branch retinal vein occlusion in a single-center prospective study: visual outcomes and microaneurysm formation.

PURPOSE: The aim of this study is to report the 6-month results after one intravitreal ranibizumab (IVR) injection followed by pro re nata dosing for macular edema (ME) after branch retinal vein occlusion. PATIENTS AND METHODS: The inclusion criteria included a minimal patient age of 18 years, 20 letters or more best-corrected visual acuity (BCVA) (Early Treatment Diabetic Retinopathy Study [ETDRS] score, 77 letters or less), and central retinal thickness (CRT) of 250 microns or more. The primary outcome measure was the mean BCVA change from baseline at month 6; the secondary outcomes were mean changes in CRT, residual ME, and microaneurysm formation. RESULTS: Twenty patients were enrolled from March 2014 through October 2016 at Nagoya City University Hospital. The baseline mean ETDRS letters and CRT were 63.1 and 500 microns, respectively; mean time from symptom onset to initial therapy was 1.80 months; and mean ETDRS gain and CRT reduction were 15.2 letters and 230 microns, respectively. The percentages of patients with Snellen equivalent BCVAs of 20/40 (70 ETDRS letters) or better and 20/20 (85 ETDRS letters) were 90% and 15%, respectively. Residual ME and microaneurysms were observed in 85% and 35% of patients. Microaneurysm formation was associated with delayed initial therapy. CONCLUSION: Prompt initiation of IVR injection provided a better visual prognosis at month 6 and suppressed the microaneurysm formation.

A Case of Euthyroid Graves' Ophthalmopathy in a Patient Sero-Negative for TSH Receptor Autoantibody.

We report of a case of Graves' ophthalmopathy presented solely with symptoms of the eyes with normal thyroid function tests and negative immunoreactive TSH receptor autoantibody. 40-year-old male was referred to our hospital due to 2-month history of ocular focusing deficit without any signs or symptoms of hyper- or hypothyroidism. Serum thyroid function tests and 99mTc uptake were both within the normal range. Anti-thyroid autoantibodies were all negative except for the cell-based assay for serum TSH receptor stimulating activity. Since orbital CT scan and MRI gave typical results compatible with Graves' ophthalmopathy, we treated the patients with corticosteroid pulse therapy and orbital radiation therapy, leading to a partial improvement of the symptoms. This case gives insights into the potential pathophysiologic mechanism underlying Graves' ophthalmopathy and casts light upon the difficulties of establishing the diagnosis in a euthyroid case with minimal positive results for anti-thyroid autoantibodies.

Patient-Specific Human Induced Pluripotent Stem Cell Model Assessed with Electrical Pacing Validates S107 as a Potential Therapeutic Agent for Catecholaminergic Polymorphic Ventricular Tachycardia.

INTRODUCTION: Human induced pluripotent stem cells (hiPSCs) offer a unique opportunity for disease modeling. However, it is not invariably successful to recapitulate the disease phenotype because of the immaturity of hiPSC-derived cardiomyocytes (hiPSC-CMs). The purpose of this study was to establish and analyze iPSC-based model of catecholaminergic polymorphic ventricular tachycardia (CPVT), which is characterized by adrenergically mediated lethal arrhythmias, more precisely using electrical pacing that could promote the development of new pharmacotherapies. METHOD AND RESULTS: We generated hiPSCs from a 37-year-old CPVT patient and differentiated them into cardiomyocytes. Under spontaneous beating conditions, no significant difference was found in the timing irregularity of spontaneous Ca2+ transients between control- and CPVT-hiPSC-CMs. Using Ca2+ imaging at 1 Hz electrical field stimulation, isoproterenol induced an abnormal diastolic Ca2+ increase more frequently in CPVT- than in control-hiPSC-CMs (control 12% vs. CPVT 43%, p<0.05). Action potential recordings of spontaneous beating hiPSC-CMs revealed no significant difference in the frequency of delayed afterdepolarizations (DADs) between control and CPVT cells. After isoproterenol application with pacing at 1 Hz, 87.5% of CPVT-hiPSC-CMs developed DADs, compared to 30% of control-hiPSC-CMs (p<0.05). Pre-incubation with 10 µM S107, which stabilizes the closed state of the ryanodine receptor 2, significantly decreased the percentage of CPVT-hiPSC-CMs presenting DADs to 25% (p<0.05). CONCLUSIONS: We recapitulated the electrophysiological features of CPVT-derived hiPSC-CMs using electrical pacing. The development of DADs in the presence of isoproterenol was significantly suppressed by S107. Our model provides a promising platform to study disease mechanisms and screen drugs.

Exon 3 deletion of RYR2 encoding cardiac ryanodine receptor is associated with left ventricular non-compaction.

AIMS: Ryanodine receptor gene (RYR2) mutations are well known to cause catecholaminergic polymorphic ventricular tachycardia (CPVT). Recently, RYR2 exon 3 deletion has been identified in patients with dilated cardiomyopathy (DCM) and/or CPVT. This study aimed to screen for the RYR2 exon 3 deletion in CPVT probands, characterize its clinical pathology, and confirm the genomic rearrangement. METHODS AND RESULTS: Our cohort consisted of 24 CPVT probands. Polymerase chain reaction (PCR)-based conventional genetic analysis did not identify any mutations in coding exons of RYR2 in these probands. They were screened using multiplex ligation-dependent probe amplification (MLPA). In probands identified with RYR2 exon 3 deletion, the precise location of the deletion was identified by quantitative PCR and direct sequencing methods. We identified two CPVT probands from unrelated families who harboured a large deletion including exon 3. The probands were 9- and 17-year-old girls. Both probands had a history of syncope related to emotional stress or exercise, exhibited bradycardia, and were diagnosed with left ventricular non-compaction (LVNC). We examined 10 family members and identified six more RYR2 exon 3 deletion carriers. In total, there were eight carriers, of which seven were diagnosed with LVNC (87.5%). Two carriers under the age of 4 years remained asymptomatic, although they were diagnosed with LVNC. Using quantitative PCR and direct sequencing, we confirmed that the deletions were 1.1 and 37.7 kb in length. CONCLUSION: RYR2 exon 3 deletion is frequently associated with LVNC. Therefore, detection of the deletion offers a new modality for predicting the prognosis of patients with LVNC with ventricular/atrial arrhythmias, particularly in children.

Genetic background of catecholaminergic polymorphic ventricular tachycardia in Japan.

BACKGROUND: The genetic background of catecholaminergic polymorphic ventricular tachycardia (CPVT) has been extensively investigated for the last decade in Western countries, but it remains unstudied in the Asian population. METHODS AND RESULTS: In 50 Japanese probands from unrelated families who satisfied clinical criteria for CPVT, genetic testing was conducted in all exons on 3 CPVT-related genes: cardiac ryanodine receptor 2 (RYR2), calsequestrin 2 (CASQ2) and inward rectifier potassium channel 2 (KCNJ2), and the clinical features between RYR2-genotyped and -non-genotyped patient groups were compared. Genetic and clinical evaluation was also done in 46 family members. In the genetic screening, 28 (18 novel) RYR2 (56.0%), 1 compound heterozygous CASQ2 (2.0%) and 1 KCNJ2 (2.0%) mutation carriers were identified. In the RYR2 mutation-positive group, the frequency of bidirectional ventricular tachycardia and the use of ß-blockers were significantly higher than in the mutation-negative group. In contrast, there was no significant difference in supraventricular arrhythmias between the 2 groups. With regard to disease penetrance, the number of family members of RYR2-genotyped probands with a clinical diagnosis of CPVT was high. CONCLUSIONS: Thirty gene mutation carriers were found for 3 genes in 50 probands clinically diagnosed as having CPVT. The penetrance of CPVT phenotype was significantly higher in RYR2 mutation carriers, thus RYR2 gene screening in CPVT patients would be indispensable to prevent unexpected cardiac sudden death of young family members.

Seasonal and circadian distributions of cardiac events in genotyped patients with congenital long QT syndrome.

BACKGROUND: Although the incidence of ventricular tachyarrhythmias associated with structural heart disease is highest in winter and during the daytime, seasonal and circadian variations among cardiac events in patients with congenital long QT syndrome (LQTS) remain unknown. The present study aims to determine seasonal and circadian cardiac events in patients with a congenital LQTS genotype. METHODS AND RESULTS: The medical records of 196 consecutive patients with symptomatic LQTS (age, 32 ± 19 years; female, n=133; LQT1, n=86; LQT2, n=95; LQT3, n=15) who were genotyped between 1979 and 2006 at 2 major Japanese institutions were retrospectively analyzed. The patients with LQT1, LQT2, and LQT3 developed 223,550 and 59 cardiac events during a mean follow-up of 26, 33, and 25 years, respectively. The numbers of cardiac events significantly peaked during the summer among those with LQT1 (P<0.001) and from summer to fall in those with LQT2 (P<0.001), but reached the nadir in winter among those with LQT3 (P=0.003). Cardiac events significantly peaked in the afternoon (12:00-17:59) and morning (06:00-11:59) among those with LQT1 (P<0.001) and LQT2 (P<0.001). CONCLUSIONS: The frequency of cardiac events was specifically seasonal and circadian among patients with the 3 major genotypes of congenital LQTS.

Phenotype variability in patients carrying KCNJ2 mutations.

BACKGROUND: Mutations of KCNJ2, the gene encoding the human inward rectifier potassium channel Kir2.1, cause Andersen-Tawil syndrome (ATS), a disease exhibiting ventricular arrhythmia, periodic paralysis, and dysmorphic features. However, some KCNJ2 mutation carriers lack the ATS triad and sometimes share the phenotype of catecholaminergic polymorphic ventricular tachycardia (CPVT). We investigated clinical and biophysical characteristics of KCNJ2 mutation carriers with "atypical ATS." METHODS AND RESULTS: Mutational analyses of KCNJ2 were performed in 57 unrelated probands showing typical (≥2 ATS features) and atypical (only 1 of the ATS features or CPVT) ATS. We identified 24 mutation carriers. Mutation-positive rates were 75% (15/20) in typical ATS, 71% (5/7) in cardiac phenotype alone, 100% (2/2) in periodic paralysis, and 7% (2/28) in CPVT. We divided all carriers (n=45, including family members) into 2 groups: typical ATS (A) (n=21, 47%) and atypical phenotype (B) (n=24, 53%). Patients in (A) had a longer QUc interval [(A): 695 ± 52 versus (B): 643 ± 35 ms] and higher U-wave amplitude (0.24 ± 0.07 versus 0.18 ± 0.08 mV). C-terminal mutations were more frequent in (A) (85% versus 38%, P<0.05). There were no significant differences in incidences of ventricular tachyarrhythmias. Functional analyses of 4 mutations found in (B) revealed that R82Q, R82W, and G144D exerted strong dominant negative suppression (current reduction by 95%, 97%, and 96%, respectively, versus WT at -50 mV) and T305S moderate suppression (reduction by 89%). CONCLUSIONS: KCNJ2 gene screening in atypical ATS phenotypes is of clinical importance because more than half of mutation carriers express atypical phenotypes, despite their arrhythmia severity.

Atrioventricular block-induced Torsades de Pointes with clinical and molecular backgrounds similar to congenital long QT syndrome.

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 I(Ks) or I(Kr). 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.

Latent genetic backgrounds and molecular pathogenesis in drug-induced long-QT syndrome.

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<0.05). When reconstituted in Chinese hamster ovary cells, 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.

D85N, a KCNE1 polymorphism, is a disease-causing gene variant in long QT syndrome.

OBJECTIVES: This study aims to address whether D85N, a KCNE1 polymorphism, is a gene variant that causes long QT syndrome (LQTS) phenotype. BACKGROUND: KCNE1 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. METHODS: In 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. RESULTS: The 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. CONCLUSIONS: The 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 approximately 1% among control individuals, KCNE1-D85N may be a clinically important genetic variant.

Brain-derived neurotrophic factor enhances the basal rate of protein synthesis by increasing active eukaryotic elongation factor 2 levels and promoting translation elongation in cortical neurons.

The constitutive and activity-dependent components of protein synthesis are both critical for neural function. Although the mechanisms controlling extracellularly induced protein synthesis are becoming clear, less is understood about the molecular networks that regulate the basal translation rate. Here we describe the effects of chronic treatment with various neurotrophic factors and cytokines on the basal rate of protein synthesis in primary cortical neurons. Among the examined factors, brain-derived neurotrophic factor (BDNF) showed the strongest effect. The rate of protein synthesis increased in the cortical tissues of BDNF transgenic mice, whereas it decreased in BDNF knock-out mice. BDNF specifically increased the level of the active, unphosphorylated form of eukaryotic elongation factor 2 (eEF2). The levels of active eEF2 increased and decreased in BDNF transgenic and BDNF knock-out mice, respectively. BDNF decreased kinase activity and increased phosphatase activity against eEF2 in vitro. Additionally, BDNF shortened the ribosomal transit time, an index of translation elongation. In agreement with these results, overexpression of eEF2 enhanced protein synthesis. Taken together, our results demonstrate that the increased level of active eEF2 induced by chronic BDNF stimulation enhances translational elongation processes and increases the total rate of protein synthesis in neurons.

Dynamic change in ST-segment and spontaneous occurrence of ventricular fibrillation in Brugada syndrome with a novel nonsense mutation in the SCN5A gene during long-term follow-up.

A 67-year-old male underwent genetic testing under the diagnosis of Brugada syndrome because of recurrent ventricular fibrillation with coincident ST-segment elevation in either right precordial, inferior leads or both since the age of 55 years. Screening of gene mutations using denaturing high-performance liquid chromatography (DHPLC) and direct sequencing identified a novel nonsense mutation (R179X) of SCN5A in a heterozygous manner. The functional assay for the identified mutation, using a whole-cell patch clamp in the heterologous expression system, revealed that the nonsense mutation, located in the second transmembrane segment of the first domain (DI-S2) of the alpha-subunit, failed to synthesize the complete structure of the cardiac sodium channel, thus causing the non-functional channel. Coding effects by the gene mutation was altered during the 12-year follow-up, which might affect the clinical features of the patient through the ion channel density in the ventricle, dynamics of repolarization abnormality and conduction disturbance.

Brain-derived neurotrophic factor induces mammalian target of rapamycin-dependent local activation of translation machinery and protein synthesis in neuronal dendrites.

In neurons, perisynaptic or dendritic translation is implicated in synapse-wide alterations of function and morphology triggered by neural activity. The molecular mechanisms controlling local translation activation, however, have yet to be elucidated. Here, we show that local protein synthesis and translational activation in neuronal dendrites are upregulated by brain-derived neurotrophic factor (BDNF) in a rapamycin and small interfering RNA specific for mammalian target of rapamycin (mTOR)-sensitive manner. In parallel, BDNF induced the phosphorylation of tuberin and the activation of mTOR in dendrites and the synaptoneurosome fraction. mTOR activation stimulated translation initiation processes involving both eIF4E/4E-binding protein (4EBP) and p70S6 kinase/ribosomal S6 protein. BDNF induced phosphorylation of 4EBP in isolated dendrites. Moreover, local puff application of BDNF to dendrites triggered S6 phosphorylation in a restricted area. Taken together, these data indicate that mTOR-dependent translation activation is essential for the upregulation of local protein synthesis in neuronal dendrites.