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BackgroundDespite the accumulating genetic and molecular investigations into hypertrophic cardiomyopathy (HCM), it remains unclear how this condition develops and worsens pathologically and clinically in terms of the genetic–environmental interactions. Establishing a human disease model for HCM would help to elucidate these disease mechanisms; however, cardiomyocytes from patients are not easily obtained for basic research. Patient‐specific induced pluripotent stem cells (iPSCs) potentially hold much promise for deciphering the pathogenesis of HCM. The purpose of this study is to elucidate the interactions between genetic backgrounds and environmental factors involved in the disease progression of HCM.Methods and ResultsWe generated iPSCs from 3 patients with HCM and 3 healthy control subjects, and cardiomyocytes were differentiated. The HCM pathological phenotypes were characterized based on morphological properties and high‐speed video imaging. The differences between control and HCM iPSC‐derived cardiomyocytes were mild under baseline conditions in pathological features. To identify candidate disease‐promoting environmental factors, the cardiomyocytes were stimulated by several cardiomyocyte hypertrophy‐promoting factors. Interestingly, endothelin‐1 strongly induced pathological phenotypes such as cardiomyocyte hypertrophy and intracellular myofibrillar disarray in the HCM iPSC‐derived cardiomyocytes. We then reproduced these phenotypes in neonatal cardiomyocytes from the heterozygous Mybpc3‐targeted knock in mice. High‐speed video imaging with motion vector prediction depicted physiological contractile dynamics in the iPSC‐derived cardiomyocytes, which revealed that self‐beating HCM iPSC‐derived single cardiomyocytes stimulated by endothelin‐1 showed variable contractile directions.ConclusionsInteractions between the patient's genetic backgrounds and the environmental factor endothelin‐1 promote the HCM pathological phenotype and contractile variability in the HCM iPSC‐derived cardiomyocytes.

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Background Scarce data exist about the outcomes after percutaneous coronary intervention ( PCI ) in old patients. This study sought to provide an overview of PCI in elderly patients, especially nonagenarians, in a Japanese large prospective nationwide registry. Methods and Results We analyzed 562 640 patients undergoing PCI (≥60 years of age) from 1018 Japanese hospitals between 2014 and 2016 in the J‐PCI (Japanese percutaneous coronary intervention) registry. Among them, 10 628 patients (1.9%), including 6780 (1.2%) with acute coronary syndrome ( ACS ) and 3848 (0.7%) with stable coronary artery disease, were ≥90 years of age. We investigated differences in characteristics and in‐hospital outcomes among sexagenarians, septuagenarians, octogenarians, and nonagenarians. Older patients were more frequently women and had a greater frequency of heart failure and chronic kidney disease than younger patients. In addition, older patients had a higher rate of in‐hospital mortality, cardiac tamponade, cardiogenic shock after PCI , and bleeding complications requiring blood transfusion. Nonagenarians had the highest risk of in‐hospital mortality (odds ratio, 3.60; 95% CI , 3.10–4.18 in ACS ; odds ratio , 6.24; 95% CI, 3.82–10.20 in non‐ ACS ) and bleeding complications ( odds ratio, 1.79; 95% CI, 1.35–2.36 in ACS ; odds ratio , 2.70; 95% CI, 1.68–4.35 in non‐ ACS ) when referenced to sexagenarians. More important, transradial intervention was an inverse independent predictor of both in‐hospital mortality and bleeding complications. Conclusions Older patients, especially nonagenarians, carried a greater risk of in‐hospital death and bleeding compared with younger patients after PCI . Transradial intervention might contribute to risk reduction for periprocedural complications in elderly patients undergoing PCI .

BackgroundTo evaluate relationships between traumatic symptoms and environmental damage conditions among children who survived the 2011 Great East Japan Earthquake and Tsunami.MethodsThe subjects were 12,524 children in kindergartens, elementary schools, and junior high schools in Ishinomaki City, Miyagi Prefecture, Japan. The Post Traumatic Stress Symptoms for Children 15 items (PTSSC-15), a self-completion questionnaire on traumatic symptoms, was distributed to the children and a questionnaire regarding environmental damage conditions affecting the children was distributed to their teachers. Of 12,524 questionnaires distributed, an effective response was obtained from 11,692 (93.3%).ResultsThe PTSSC-15 score was significantly higher in females than in males among 4th to 6th grade students in elementary schools and among junior high school students. In terms of traumatic symptoms and environmental damage conditions, with the exception of kindergartners, children who had their houses damaged or experienced separation from family members had a significantly higher PTSSC-15 score than children who did not experience environmental damage. Except for kindergartners and 4th- to 6th-grade elementary school students, children who experienced evacuation had a significantly higher PTSSC-15 score.ConclusionsThis study demonstrated relationships between traumatic symptoms and environmental damage conditions in children who had suffered from the disaster. Factors examined in studying the relationship between environmental damage conditions and traumatic symptoms were gender, age, house damage, evacuation experience, and bereavement experience. It was critical not only to examine the traumatic symptoms of the children but also to collect accurate information about environmental damage conditions.

SCN5A is abundant in heart and has a major role in INa. Loss-of-function mutation in SCN5A results in Brugada syndrome (BrS), which causes sudden death in adults. It remains unclear why disease phenotype does not manifest in the young even though mutated SCN5A is expressed in the young. The aim of the present study is to elucidate the timing of the disease manifestation in BrS. A gain-of-function mutation in SCN5A also results in Long QT syndrome type 3 (LQTS3), leading to sudden death in the young. Induced pluripotent stem cells (iPSCs) were generated from a patient with a mixed phenotype of LQTS3 and BrS with the E1784K SCN5A mutation. Here we show that electrophysiological analysis revealed that LQTS3/BrS iPSC-derived cardiomyocytes recapitulate the phenotype of LQTS3 but not BrS. Each β-subunit of the sodium channel is differentially expressed in embryonic and adult hearts. SCN3B is highly expressed in embryonic hearts and iPSC-derived cardiomyocytes. A heterologous expression system revealed that INa of mutated SCN5A is decreased and SCN3B augmented INa of mutated SCN5A. Knockdown of SCN3B in LQTS3/BrS iPSC-derived cardiomyocytes successfully unmasked the phenotype of BrS. Isogenic control of LQTS3/BrS (corrected-LQTS3/BrS) iPSC-derived cardiomyocytes gained the normal electrophysiological properties.

HighlightsWe modeled the mitochondrial disease MELAS by generating patient-specific iPS cells.MELAS-iPS cells show a wide variety of heteroplasmy levels.MELAS-iPS cells with high heteroplasmy levels showed impaired complex I activity.

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