Dasatinib can Impair Left Ventricular Mechanical Function But May Lack Proarrhythmic Effect: A Proposal of Non-clinical Guidance for Predicting Clinical Cardiovascular Adverse Events of Tyrosine Kinase Inhibitors

Tyrosine kinase inhibitors are known to clinically induce various types of cardiovascular adverse events; however, it is still difficult to predict them at preclinical stage. In order to explore how to better predict such drug-induced cardiovascular adverse events, we tried to develop a new protocol by assessing acute electrophysiological, cardiohemodynamic, and cytotoxic effects of dasatinib in vivo and in vitro. Dasatinib at 0.03 and 0.3 mg/kg was intravenously administered to the halothane-anesthetized dogs for 10 min with an interval of 20 min between the dosing (n = 4). Meanwhile, that at 0.1, 0.3, and 1 μM was cumulatively applied to the human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) (n = 7). In the dogs, the low and high doses provided peak plasma concentrations of 40 ± 5 (0.08) and 615 ± 38 ng/mL (1.26 μM), respectively. The low dose decreased the heart rate, impaired the left ventricular mechanical function, and prolonged the ventricular effective refractory period. The high dose prolonged the repolarization period, induced hemorrhagic tendency, and increased plasma cardiac troponin I level in addition to enhancement of the changes observed after the low dose, whereas it neither affected the cardiac conduction nor induced ventricular arrhythmias. In the hiPSC-CMs, dasatinib prolonged the repolarization and refractory periods like in dogs, while it did not induce apoptotic or necrotic process, but that it increased the conduction speed. Clinically observed major cardiovascular adverse events of dasatinib were observed qualitatively by currently proposed assay protocol, which may become a useful guide for predicting the cardiotoxicity of new tyrosine kinase inhibitors.

In vivo comparison of dl-sotalol-induced electrocardiographic responses among halothane anesthesia, isoflurane anesthesia with nitrous oxide, and conscious state

We compared dl-sotalol-induced electrocardiographic responses in intact dogs using a repeated-measures design among 1% halothane anesthesia, 1.5% isoflurane anesthesia with nitrous oxide (N₂O), and conscious state to clarify influences of the anesthetics (n = 4). Basal PR interval was longer in halothane than either in isoflurane with N₂O or in conscious state, reflecting sympathetic nerve suppression for the atrioventricular node by halothane. Both anesthetics exhibited longer basal QRS width than conscious state, suggesting their ventricular I_Na inhibition. Also, both anesthetics showed longer basal QT interval, QTcF and T_peak-T_end than conscious state, indicating their ventricular I_Kr inhibition. Meanwhile, dl-sotalol prolonged PR interval similarly in isoflurane with N₂O and in conscious state, which was less great in halothane, suggesting further sympathetic nerve suppression for the atrioventricular node might be limited in halothane. dl-Sotalol prolonged QT interval and QTcF >3 times greater in either of the anesthetics than in conscious state; moreover, dl-sotalol prolonged T_peak-T_end similarly in both anesthetics, but hardly altered it in conscious state; indicating isoflurane with N₂O as well as halothane may have reduced the repolarization reserve to increase the sensitivity of ventricle toward I_Kr suppression. Thus, isoflurane with nitrous oxide could be useful for in vivo I_Kr assay like halothane.

Optimizing the Direction and Order of the Motion Unveiled the Ability of Conventional Monolayers of Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes to Show Frequency-Dependent Enhancement of Contraction and Relaxation Motion

Contractility of the human heart increases as its beating rate is elevated, so-called positive force-frequency relationship; however, human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) have been reported to exert a negative force-frequency relationship. We tested the hypothesis that the regulation of motion directions by electrical pacing and/or oxygen supply may improve the electro-mechanical properties of hiPSC-CMs monolayers. To better evaluate the spatial and temporal relationship between electrical excitation and contractile motion, we simultaneously observed the field potential and motion vector of hiPSC-CMs sheets. Under spontaneous contraction, although an electrical excitation originating from a region propagated unidirectionally over the cell sheet, contraction wave started from multiple sites, and relaxation wave was initiated from a geometric center of hiPSC-CMs sheet. During electrical pacing, contraction and relaxation waves were propagated from the stimulated site. Interestingly, the maximum contraction speed was more increased when the hiPSC-CMs sheet was stimulated at an area relaxation initiated under spontaneous condition. Furthermore, motion vector analysis demonstrated that "positive contraction velocity-frequency relationship" in contraction and "frequency-dependent enhancement of relaxation" were produced in the cell sheet by optimizing the direction and order of the contractile motion with pacing at the relaxation-initiating area. A close analysis of motion vectors along with field potential recording demonstrated that relaxation process consists of fast and slow phases, and suggest that intracellular Ca²⁺ dynamics may be closely related to functions of Ca²⁺-ATPase pump and Na⁺-Ca²⁺ exchangers. Namely, the slow relaxation phase occurred after the second peak of field potential, suggesting that the slow phase may be associated with extrusion of Ca²⁺ by Na⁺-Ca²⁺ exchangers during repolarization. Increase of oxygen concentration from 20 to 95% as well as β-adrenergic stimulation with isoproterenol accelerated the fast relaxation, suggesting that it could depend on Ca²⁺ uptake via Ca²⁺-ATPase during the depolarization phase. The ratio of maximum contraction speed to field potential duration was increased by the β-adrenergic stimulation, indicating the elevated contraction efficiency per Ca²⁺-influx. Thus, these findings revealed potential ability of conventional monolayers of hiPSC-CMs, which will help apply them to translational study filling the gap between physiological as well as pharmacological studies and clinical practice.

Association between Polygenic Risk Score and One-Year Outcomes Following As-Needed Aflibercept Therapy for Exudative Age-Related Macular Degeneration

We investigated whether polygenic risk score (PRS) was associated with one-year outcome of as-needed aflibercept therapy for exudative age-related macular degeneration (AMD), including AMD (n = 129) and polypoidal choroidal vasculopathy (n = 132). A total of 261 patients were treated with as-needed intravitreal aflibercept injection (IAI) after three monthly IAIs and the completion of a one-year follow-up. One hundred and seventy-two healthy volunteers served as controls. Genotyping of ARMS2 A69S (rs10490924), CFH I62V (rs800292), SKIV2L-C2-CFB (rs429608), C3 (rs2241394), ADAMTS-9 (rs6795735) and CETP (rs3764261) was performed for all participants. A total of 63 PRSs were quantified. There was a positive association between the PRS involving ARMS2, CFH, C3, and ADAMTS-9 and best-corrected visual acuity at twelve months (p = 0.046, multiple regression analysis). When comparing PRSs of patients requiring retreatment and of patients without retreatment, 35 PRSs were significantly greater in patients requiring retreatment than in patients without requiring retreatment, with the PRS involving ARMS2 and CFH being most significantly associated (p = 1.6 × 10⁻⁴). The number of additional injections was significantly associated with 40 PRSs and the PRS involving ARMS2 and CFH showed a most significant p-value (p = 2.42 × 10⁻⁶). Constructing a PRS using a combination with high-risk variants might be informative for predicting the response to IAI for exudative AMD.

Characterization of Magnesium Sulfate as an Antiarrhythmic Agent

Background

Recently, intravenous magnesium therapy has been used for the treatment of ventricular arrhythmias, but data to establish a causal link between the electrophysiological properties and the antiarrhythmic actions are lacking.

Methods and Results

The acute antiarrhythmic effect of magnesium sulfate was assessed using epinephrine-, digitalis-, and coronary ligation-induced canine ventricular arrhythmia models. The intravenous administration of magnesium sulfate (100 mg/kg) reduced the incidence of the ventricular arrhythmias of all models. The antiarrhythmic effect on the epinephrine-induced arrhythmia was potent and long-lasting, while those on the other arrhythmia models were weak and transient. The direct cardiovascular effects were assessed using the canine isolated, blood-perfused sinus node, papillary muscle, and atrioventricular node preparations. The intracoronary administration of magnesium sulfate (0.1–30 mg) suppressed sinoatrial automaticity and ventricular contraction, while it increased atrio-His and His-ventricular conduction time, coronary blood flow, and the duration of monophasic action potential in a dose-dependent manner. The effects on His-ventricular conduction and monophasic action potential duration were less potent compared with the other cardiovascular effects.

Conclusion

These results suggest that magnesium sulfate possesses multiple electrophysiological properties and that the effects related to the calcium channel inhibition may be the most relevant for the antiarrhythmic actions.

Response to photodynamic therapy combined with intravitreal aflibercept for polypoidal choroidal vasculopathy depending on fellow-eye condition:2-year results

We investigated whether response to photodynamic therapy (PDT) with intravitreal aflibercept injection (IAI) for polypoidal choroidal vasculopathy (PCV) differs depending on fellow eye condition. A retrospective review was conducted for consecutive 60 eyes with PCV treated with PDT combined with IAI as well as 2-years of follow-up data. Fellow eyes were divided into 4 groups; Group 0: no drusen, Group 1; pachydrusen, Group 2; soft drusen, Group 3: PCV/fibrovascular scarring. Best-corrected visual acuity improved at 24-months irrespective of groups and there were no significant differences in visual improvement among treated eyes among the 4 groups. Within 2-years, 35 (58.3%) required the retreatment. The need for retreatment including additional injection and the combination therapy was significantly less in Group 1(12.5%) compared to the others (P = 0.0038) and mean number of additional IAI was also less in Group 1 compared to the others (P = 0.017). The retreatment-free period from the initial combination therapy was longest in Group 1 (23.6±1.1 months) (P = 0.0055, Group 0: 19.1±6.9, Group 2: 12.8±7.9, Group 3: 11.5±9.9). The need for retreatment was significantly different according to fellow-eye condition. Among PCV patients, pachydrusen in fellow eyes appear to be a predictive characteristic for a decreased treatment burden at 2 years.

Title: Pachydrusen in Fellow Eyes Predict Response to Aflibercept Monotherapy in Patients with Polypoidal Choroidal Vasculopathy

We investigated whether responses to as-needed intravitreal aflibercept injections (IAIs) for polypoidal choroidal vasculopathy (PCV) differed among patients based upon drusen characteristics in fellow eyes. 110 eyes from 110 patients with PCV received 3 monthly IAI and thereafter Pro re nata (PRN) IAI over 12 months. Patients were classified into 4 groups depending on fellow eye findings. Group 1 (n = 16): pachydrusen; Group 2 (n = 45): no drusen; Group 3 (n = 35): soft drusen; Group4 (n = 14) PCV/scarring. Best-corrected visual acuity improved at 12 months in all groups, but not significantly in Group 1 and Group 4; however, visual improvement was similar among the groups after adjusting baseline confounders. Group 1 had a significantly lower percentage of eyes needing retreatment (all p < 0.001; Group 1: 16.7%; Group 2: 50.8%; Group 3: 80%; Group 4: 85.7%). The mean number of retreatments was least in Group 1 among the groups (all p-value < 0.003; Group 1: 0.50 ± 1.32; Group 2: 1.73 ± 2.08; Group 3:2.71 ± 1.99; Group 3: 2.71 ± 2.16). Patients with pachydrusen in fellow eyes were less likely to require additional IAI following the loading dose and may be ideal candidates for aflibercept monotherapy in their first year.

Optimal Combination of Compression Rate and Depth During Cardiopulmonary Resuscitation for Functionally Favorable Survival

Importance

Previous studies of basic cardiopulmonary resuscitation (CPR) indicate that both chest compression rate (CCR) and chest compression depth (CCD) each are associated with survival probability after out-of-hospital cardiac arrest. However, an optimal CCR-CCD combination has yet to be identified, particularly with respect to age, sex, presenting cardiac rhythm, and CPR adjunct use.

Objectives

To identify an ideal CCR-CCD combination associated with the highest probability of functionally favorable survival and to assess whether this combination varies with respect to age, sex, presenting cardiac rhythm, or CPR adjunct use.

Design, Setting, and Participants

This cohort study used data collected between June 2007 and November 2009 from a National Institutes of Health (NIH) clinical trials network registry of out-of-hospital and in-hospital emergency care provided by 9-1-1 system agencies participating in the network across the United States and Canada (n = 150). The study sample included 3643 patients who had out-of-hospital cardiac arrest and for whom CCR and CCD had been simultaneously recorded during an NIH clinical trial of a CPR adjunct. Subgroup analyses included evaluations according to age, sex, presenting cardiac rhythm, and application of a CPR adjunct. Data analysis was performed from September to November 2018.

Interventions

Standard out-of-hospital cardiac arrest interventions compliant with the concurrent American Heart Association guidelines as well as use of the CPR adjunct device in half of the patients.

Main Outcomes and Measures

The optimal combination of CCR-CCD associated with functionally favorable survival (modified Rankin scale ≤3) overall and by age, sex, presenting cardiac rhythm, and CPR adjunct use.

Results

Of 3643 patients, 2346 (64.4%) were men; the mean (SD) age was 67.5 (15.7) years. The identified optimal CCR-CCD for all patients was 107 compressions per minute and a depth of 4.7 cm. When CPR was performed within 20% of this value, survival probability was significantly higher (6.0% vs 4.3% outside that range; odds ratio, 1.44; 95% CI, 1.07-1.94; P = .02). The optimal CCR-CCD combination remained similar regardless of age, sex, presenting cardiac rhythm, or CPR adjunct use. The identified optimal CCR-CCD was associated with significantly higher probabilities of survival when the CPR device was used compared with standard CPR (odds ratio, 1.90; 95% CI, 1.06-3.38; P = .03), and the device's effectiveness was dependent on being near the target CCR-CCD combination.

Conclusions and Relevance

The findings suggest that the combination of 107 compressions per minute and a depth of 4.7 cm is associated with significantly improved outcomes for out-of-hospital cardiac arrest. The results merit further investigation and prospective validation.

A Compact Mid-Infrared Spectroscopy System for Healthcare Applications Based on a Wavelength-Swept, Pulsed Quantum Cascade Laser

A mid-infrared spectroscopic system using a high-speed wavelength-swept and pulsed quantum cascade laser (QCL) for healthcare applications such as blood glucose measurement is proposed. We developed an attenuated total reflection measurement system comprising the QCL with a micro-electromechanical system (MEMS)-scanning grating, hollow optical fibers, and InAsSb detector and tested its feasibility for healthcare applications. A continuous spectrum was obtained by integrating comb-shaped spectra, the timing of which was slightly shifted. As this method does not require complex calculations, absorption spectra are obtained in real-time. We found that the signal-to-noise ratio of the obtained spectrum had been improved by increasing the number of spectra that were integrated into the spectrum calculation. Accordingly, we succeeded in measuring the absorption spectrum of a 0.1% aqueous glucose solution. Furthermore, the absorption spectra of human lips were measured, and it was shown that estimation of blood glucose levels were possible using a model equation derived using a partial least squares regression analysis of the measured absorption spectra. The spectroscopic system based on the QCL with MEMS-scanning grating has the advantages of compactness and low cost over conventional Fourier transform infrared-based systems and common spectroscopic systems with a tunable QCL that has a relatively large, movable grating.

Analysis of electropharmacological effects of AVE0118 on the atria of chronic atrioventricular block dogs: characterization of anti-atrial fibrillatory action by atrial repolarization-delaying agent

AVE0118, an inhibitor of I_Kur, I_to and I_K,ACh, was in the drug pipeline for atrial fibrillation. To investigate the limitation of AVE0118 as an anti-atrial fibrillatory drug, we studied its electropharmacological effects particularly focusing on the anti-atrial fibrillatory action as reverse translational research. We adopted the chronic atrioventricular block beagle dogs (n = 4), having a pathophysiology of bradycardia-associated, volume overload-induced chronic heart failure, in which the atrial fibrillation was induced by 10 s of burst pacing on atrial septum. AVE0118 in doses of 0.24 and 1.2 mg/kg, i.v. over 10 min hardly altered electrophysiological variables. Meanwhile, AVE0118 in a dose of 6 mg/kg, i.v. over 10 min delayed the inter-atrial conduction in a frequency-dependent manner and prolonged the atrial effective refractory period in a reverse frequency-dependent manner, whereas it did not significantly alter the duration of atrial fibrillation or its cycle length. The increment of atrial effective refractory period was 3.3 times greater compared with that of ventricular one at a basic cycle length of 400 ms. Torsade de pointes was not induced during the experimental period. Thus, AVE0118 may possess a favorable cardiac safety pharmacological profile, but its weak anti-atrial fibrillatory effect would indicate the limitation of atrial repolarization-delaying agents for suppressing atrial fibrillation.

Characterization of microminipig as a laboratory animal for pharmacological study by analyzing bepridil-induced cardiovascular responses

Since microminipig is becoming attractive model for various cardiac electropharmacological applications, which may meet consideration of 3Rs. We characterized microminipigs by analyzing how multi-ionic channel inhibitor bepridil may affect their in situ hearts in comparison with dogs. Bepridil in doses of 0.3 and 3.0 mg/kg were intravenously administered over 10 min under halothane anesthesia (n = 4). Microminipigs may be less sensitive for I_CaT inhibition of bepridil, whereas they are more responsive to I_Na, I_Kr and I_Ks suppression than dogs. This information would help predict cardiovascular effects of a drug in patients with the remodeled hearts having similar electrophysiological profile to microminipigs.

Five-year outcomes of photodynamic therapy combined with intravitreal injection of ranibizumab or aflibercept for polypoidal choroidal vasculopathy

We report 5-year visual and anatomical outcomes after combination therapy of photodynamic therapy (PDT) and intravitreal injection of ranibizumab or aflibercept for polypoidal choroidal vasculopathy (PCV) and predictive factors for visual outcomes at 5-year and time to recurrence. Medical charts were retrospectively reviewed for 43 consecutive eyes with PCV treated with combination therapy of PDT and intravitreal injection of ranibizumab(n = 13) or aflibercept(n = 30) and completed 5-year follow-up. The variants of ARMS2 A69S and CFH I62V were genotyped using TaqMan assay. Best corrected visual acuity (BCVA) significantly improved at 5-year (P = 0.01) with 20% reduction of subfoveal choroidal thickness irrespective of presence or absence of recurrence. Visual improvement was associated with baseline shorter greatest linear dimension (GLD) (P = 1.0×10-4). Mean time to recurrence was 28.6±23.1 months (95% CI: 21.5-35.7, Median:18.0) and time to recurrence was associated with G allele (protective allele) of ARMS2 A69S and GLD (P = 4.0×10-4 and 1.0×10-2, respectively). Multiple regression analysis revealed that time to recurrence extended by 15.5 months when the G allele of ARMS2 A69S increased by one allele (TT: 15.7±17.0, TG: 30.8±23.5, GG: 41.1±22.6 months). The combination therapy resulted in a favorable visual outcome for PCV during 5-year follow-up.

Effects of the Fluoroquinolones Moxifloxacin and Levofloxacin on the QT Subintervals: Sex Differences in Ventricular Repolarization

Women are associated with longer electrocardiographic QT intervals and increased proarrhythmic risks of QT‐prolonging drugs. The purpose of this study was to characterize the differences in cardiac electrophysiology between moxifloxacin and levofloxacin in men and women and to assess the balance of inward and outward currents through the analysis of QT subintervals. Data from 2 TQT studies were used to investigate the impact of moxifloxacin (400 mg) and levofloxacin (1000 and 1500 mg) on QT subintervals using algorithms for measurement of J‐T_peak and T_peak‐T_end intervals. Concentration‐effect analyses were performed to establish potential relationships between the ECG effects and the concentrations of the 2 fluoroquinolones. Moxifloxacin was shown to be a more potent prolonger of QT interval corrected by Fredericia (QTcF) and had a pronounced effect on J‐T_peakc. Levofloxacin had little effect on J‐T_peakc. For moxifloxacin, the concentration‐effect modeling showed a greater effect for women on QTcF and J‐T_peakc, whereas for levofloxacin the inverse was true: women had smaller QTcF and J‐T_peakc effects. The different patterns in repolarization after administration of both drugs suggested a sex difference, which may be related to the combined I_Ks and I_Kr inhibitory properties of moxifloxacin versus I_Kr suppression only of levofloxacin. The equipotent inhibition of I_Ks and I_Kr appears to affect women more than men. Sex hormones are known to influence cardiac ion channel expression and differences in QT duration. Differences in I_Kr and I_Ks balances, influenced by sex hormones, may explain the results. These results support the impact of sex differences on the cardiac safety assessment of drugs.

Experimental analysis of the onset mechanism of TdP reported in an LQT3 patient during pharmacological treatment with serotonin-dopamine antagonists against insomnia and nocturnal delirium

Torsade de pointes (TdP) occurred in a long QT syndrome type 3 (LQT3) patient after switching perospirone to blonanserin. We studied how their electropharmacological effects had induced TdP in the LQT3 patient. Perospirone hydrochloride (n = 4) or blonanserin (n = 4) of 0.01, 0.1, and 1 mg/kg, i.v. was cumulatively administered to the halothane-anesthetized dogs over 10 min. The low dose of perospirone decreased total peripheral vascular resistance, but increased heart rate and cardiac output, facilitated atrioventricular conduction, and prolonged J-T_peakc. The middle dose decreased mean blood pressure and prolonged repolarization period, in addition to those observed after the low dose. The high dose further decreased mean blood pressure with the reduction of total peripheral vascular resistance; however, it did not increase heart rate or cardiac output. It tended to delay atrioventricular conduction and further delayed repolarization with the prolongation of T_peak-T_end, whereas J-T_peakc returned to its baseline level. Meanwhile, each dose of blonanserin decreased total peripheral vascular resistance, but increased heart rate, cardiac output and cardiac contractility in a dose-related manner. J-T_peakc was prolonged by each dose, but T_peak-T_end was shortened by the middle and high doses. These results indicate that perospirone and blonanserin may cause the hypotension-induced, reflex-mediated increase of sympathetic tone, leading to the increase of inward Ca²⁺ current in the heart except that the high dose of perospirone reversed them. Thus, blonanserin may have more potential to produce intracellular Ca²⁺ overload triggering early afterdepolarization than perospirone, which might explain the onset of TdP in the LQT3 patient.

In vivo characterization of rate-dependent impact on the QT interval of microminipig assessed by atrial electrical pacing: Development of correction formulae of QT interval

Correction formulae of QT interval were developed for the halothane-anesthetized microminipigs by adopting atrial pacing (n=5), which were compared with Bazett's and Fridericia's formulae for humans, and Van de Water's one for dogs. The correction formulae: QTc=QT-0.2072 (RR-750) as linear and QTc=QT/(RR/750)^0.4007 as non-linear equations, were developed for microminipigs. These formulae can better correct the QT interval of the microminipigs compared with each of the conventional ones for humans and dogs. Moreover, analysis of the slope constant α values indicates that the rate-dependent change in the ventricular repolarization period of microminipig may better mimic that of humans than that of dogs.

P5718Effects of the fluoroquinolones moxifloxacin and levofloxacin on the QT subintervals: sex differences in ventricular repolarization

Background

The effects of medicines affecting cardiac repolarization can be further evaluated by assessing the balance of inward and outward currents. These can be detected in the ECG by analysing the QT subintervals. Pure hERG potassium channel block was shown to prolong both early repolarization (J-Tpeak) and late repolarization (Tpeak-Tend), whereas multichannel blockers may shorten or have no effect on J-Tpeak.

The gender dependency of ventricular repolarization is also well known. Recently, Matsukura indicated that moxifloxacin significantly increased J-Tpeak and Tpeak-Tend and females in their study were more sensitive than males to the drug-induced J-Tpeak prolongation and QTcF.

Purpose

The purpose of the present study is to use data from two Thorough QT (TQT) studies to characterize the differences in depolarization (QRS), early repolarization (J-Tpeak), and late repolarization (Tpeak-Tend) between moxifloxacin and levofloxacin and further define the sex differences in QTc and subintervals.

Methods

Data from two TQT studies were used to further investigate the impact of moxifloxacin (400 mg) and levofloxacin (1000 and 1500 mg) on QT subintervals using validated algorithms for measurement of QRS, J-Tpeak and Tpeak–Tend intervals. Concentration-effect analyses were performed to establish a potential relationship between the ECG effects and the concentrations of the two fluoroquinolones as typically males and females also show differences in plasma concentrations due to differences in body weight.

Results

The relationships between moxifloxacin and levofloxacin plasma concentrations and their respective predicted ΔΔQTcF, ΔΔQRS, ΔΔJ-Tpeakc and ΔΔTpeak-Tend values are shown in Fig 1.

The plasma concentrations were higher for females than males in both drugs.

Moxifloxacin was shown to be a more potent prolonger of QTcF and had a pronounced effect on J-Tpeakc, consistent with its effects on both IKr and IKs channels while levofloxacin had little effect on J-Tpeakc. For moxifloxacin, the concentration-effect modelling showed a greater effect for females on QTcF and J-Tpeakc while for levofloxacin the inverse was true. Based on the assumption that repolarization reserve of females relies to a greater extent on IKs channels it would be reasonable to assume that they are more affected by a medicine that blocks IKs in addition to IKr.

Figure 1

Conclusions

This study showed that levofloxacin elicited a smaller ΔΔQTcF and ΔΔJ-Tpeakc prolongation when compared to moxifloxacin. The results of this study also showed a different pattern of sex difference in repolarization after administration of both drugs. which may suggest a difference in expression of IKs and possibly IKr channels.

Excess Heat Production by the Pair Annihilation of Ionic Vacancies in Copper Redox Reactions

In the pair annihilation of ionic vacancies with opposite charges, a drastic excess heat production up to 410 kJ mol⁻¹ in average at 10 T (i. e., 1.5 times larger than the heat production by the combustion of H₂,  285.8 kJ mol⁻¹) was observed, which was then attributed to the emission of the solvation energy stored in 0.61 nm radius vacancies with two unit charges. Under a high magnetic field, using Lorentz force, we made ionic vacancies created in copper cathodic and anodic reactions collide with each other, and measured the reaction heat by their annihilation. Ionic vacancy is initially created as a byproduct in electrode reaction in keeping the conservation of linear momentum and electric charge during electron transfer. The unstable polarized particle is stabilized by solvation, and the solvation energy is stored in the free space of the order of 0.1 nm surrounded by oppositely charged ionic cloud. The collision of the ionic vacancies was carried out by circulation-type magnetohydrodynamic electrode (c-type MHDE) composed of a rectangular channel with a pair of copper electrodes and a narrow electrolysis cell.

Clinical and genetic characteristics of pachydrusen in patients with exudative age-related macular degeneration

We investigated the clinical and genetic characteristics of patients with unilateral exudative age-related macular degeneration (AMD), including typical AMD, polypoidal choroidal vasculopathy, and retinal angiomatous proliferation, in whom pachydrusen was seen. Patients with unilateral exudative AMD with at least a 12-month follow-up period were included. According to the fellow eye condition, 327 consecutive patients were classified into 4 groups: Group 0: no drusen (42.8%), Group 1: pachydrusen (12.2%), Group 2: soft drusen (30.3%), Group 3: pseudodrusen with or without soft drusen (14.7%). Development of exudative AMD in the fellow eye was retrospectively studied for a 60-month period and this inter-group comparisons were performed. Genotyping was performed for ARMS2 A69S and CFH I62V. The thickness of the choroid in the fellow eyes increased significantly in Group 1 than in other groups (all P < 1.0 × 10⁻⁷). The development of exudative AMD in the fellow eye was significantly less frequent in Group 1 than in Groups 2 or 3 (P = 0.022 and 0.0015, respectively). Risk allele frequency of ARMS2 A69S was significantly lower in Group 1 than in Group 2 and 3 (all P < 1.0 × 10⁻⁴). Patients with pachydrusen have genetic and clinical characteristics distinct from those of soft drusen and pseudodrusen.