Viral entry and translation in brain endothelia provoke influenza-associated encephalopathy.

Influenza-associated encephalopathy (IAE) is extremely acute in onset, with high lethality and morbidity within a few days, while the direct pathogenesis by influenza virus in this acute phase in the brain is largely unknown. Here we show that influenza virus enters into the cerebral endothelium and thereby induces IAE. Three-weeks-old young mice were inoculated with influenza A virus (IAV). Physical and neurological scores were recorded and temporal-spatial analyses of histopathology and viral studies were performed up to 72 h post inoculation. Histopathological examinations were also performed using IAE human autopsy brains. Viral infection, proliferation and pathogenesis were analyzed in cell lines of endothelium and astrocyte. The effects of anti-influenza viral drugs were tested in the cell lines and animal models. Upon intravenous inoculation of IAV in mice, the mice developed encephalopathy with brain edema and pathological lesions represented by micro bleeding and injured astrocytic process (clasmatodendrosis) within 72 h. Histologically, massive deposits of viral nucleoprotein were observed as early as 24 h post infection in the brain endothelial cells of mouse models and the IAE patients. IAV inoculated endothelial cell lines showed deposition of viral proteins and provoked cell death, while IAV scarcely amplified. Inhibition of viral transcription and translation suppressed the endothelial cell death and the lethality of mouse models. These data suggest that the onset of encephalopathy should be induced by cerebral endothelial infection with IAV. Thus, IAV entry into the endothelium, and transcription and/or translation of viral RNA, but not viral proliferation, should be the key pathogenesis of IAE.

Outcomes of Restrictive Cardiomyopathy in Japanese Children　- A Retrospective Cohort Study.

BACKGROUND: There has been no nationwide survey on the prognosis of pediatric restrictive cardiomyopathy (RCM) in Japan; therefore, this retrospective multicentered study was designed to investigate the long-term survival rate of pediatric patients with RCM in Japan.Methods and Results: A multicentered, retrospective observational study was performed between 1990 and 2014 and included patients diagnosed with RCM who were aged <18 years from 18 Japanese institutions. A total of 54 patients were diagnosed with RCM. The median age at diagnosis was 4.4 years, and the median duration of observation was 2.2 years at the time of this study. Of these patients, 54% had symptoms, including heart failure. Twelve patients died without heart transplantation, mostly due to heart failure. The median time to death from diagnosis was 2.5 years. Freedom from death at 1, 5, and 10 years was 91%, 68%, and 62%, respectively. Death occurred within 5 years of diagnosis in most patients. Twenty-two patients underwent heart transplantation. Freedom from heart transplantation at 1, 5, and 10 years was 77%, 58%, and 53%, respectively. Freedom from death or heart transplantation at 1, 5, and 10 years was 72%, 40%, and 34%, respectively. The presence of symptoms was a risk factor for death or transplantation. CONCLUSIONS: The prognosis of pediatric RCM is poor, and the heart transplantation rate is low in Japan.

Outcomes of hypertrophic cardiomyopathy in Japanese children: a retrospective cohort study.

There has been no multicenter study on the prognosis of pediatric hypertrophic cardiomyopathy (HCM) in Japan. Therefore, we conducted a retrospective multicenter observational study on the long-term survival rate in patients diagnosed with HCM under the age of 18 between 1990 and 2014. Twenty institutions participated. A total of 180 patients were identified. The median age at diagnosis was 5.8 years old and median duration of observation was 8.3 years. Although six patients (3%) deteriorated into the dilated phase of HCM, no patient received heart transplantation. Freedom from death at 1, 5, 10, and 20 years were 97%, 92%, 84%, and 80%, respectively. There were 26 deaths. Among them, 11 patients died suddenly, presumably due to arrhythmia, and 15 patients died of heart failure. The presence of heart failure symptoms and a greater cardiothoracic ratio were significant risk factors for heart failure-related death. There were no significant risk factors identified for arrhythmia-related death. In conclusion, the prognosis of pediatric HCM in Japan is good and similar to those reported in population-based studies in the United States and Australia. Significant risk factors for heart failure-related death were identified in pediatric patients with HCM in Japan.

Cardiac Fibroblasts Play Pathogenic Roles in Idiopathic Restrictive Cardiomyopathy.

BACKGROUND: Restrictive cardiomyopathy (RCM) is characterized by impaired ventricular relaxation. Although several mutations were reported in some patients, no mutations were identified in cardiomyocyte expressing genes of other patients, indicating that pathological mechanisms underlying RCM could not be determined by cardiomyocytes only. Cardiac fibroblasts (CFs) are a major cell population in the heart; however, the pathological roles of CFs in cardiomyopathy are not fully understood.Methods and Results:This study established 4 primary culture lines of CFs from RCM patients and analyzed their cellular physiology, the effects on the contraction and relaxation ability of healthy cardiomyocytes under co-culture with CFs, and RNA sequencing. Three of four patients hadTNNI3mutations. There were no significant alterations in cell proliferation, apoptosis, migration, activation, and attachment. However, when CFs from RCM patients were co-cultured with healthy cardiomyocytes, the relaxation velocity of cardiomyocytes was significantly impaired both under direct and indirect co-culture conditions. RNA sequencing revealed that gene expression profiles of CFs in RCM were clearly distinct from healthy CFs. The differential expression gene analysis identified that several extracellular matrix components and cytokine expressions were dysregulated in CFs from RCM patients. CONCLUSIONS: The comprehensive gene expression patterns were altered in RCM-derived CFs, which deteriorated the relaxation ability of cardiomyocytes. The specific changes in extracellular matrix composition and cytokine secretion from CFs might affect pathological behavior of cardiomyocytes in RCM.

Electrocardiographic Diagnosis of Hypertrophic Cardiomyopathy in the Pre- and Post-Diagnostic Phases in Children and Adolescents.

BACKGROUND: The usefulness of electrocardiographic (ECG) voltage criteria for diagnosing hypertrophic cardiomyopathy (HCM) in pediatric patients is poorly defined.Methods and Results:ECGs at the 1st grade (mean [±SD] age 6.6±0.3 years) were available for 11 patients diagnosed with HCM at around the 7th grade (13.2±0.3 years). ECGs were available for another 64 patients diagnosed with HCM in the 1st (n=15), 7th (n=32), and 10th (n=17) grades. Fifty-one voltage criteria were developed by grade and sex using 62,841 ECGs from the general population. Voltage criteria were set at the 99.95th percentile (1/2,000) point based on the estimated prevalence of childhood HCM (2.9 per 100,000 [1/34,483]) to decrease false negatives. Conventional criteria were from guidelines for school-aged children in Japan. Of 11 patients before diagnosis, 2 satisfied conventional criteria in 1st grade; 5 (56%) of the remaining 9 patients fulfilled 2 voltage criteria (R wave in limb-lead I [RI]+S wave in lead V3 [SV3] and R wave in lead V3 [RV3]+SV3). Robustness analysis for sensitivity showed RV3+SV3 was superior to RI+SV3. For all patients after diagnosis, RI+SV4 was the main candidate. However, conventional criteria were more useful than voltage criteria. CONCLUSIONS: Early HCM prediction was possible using RV3+SV3 in >50% of patients in 1st grade. Voltage criteria may help diagnose prediagnostic or early HCM, and prevent tragic accidents, although further prospective studies are required.

Riociguat can ameliorate bronchopulmonary dysplasia in the SU5416 induced rat experimental model.

BACKGROUND: Bronchopulmonary dysplasia (BPD) is a chronic lung disease in premature neonates. Classical BPD is caused by hyperoxia and high-pressure mechanical ventilation, whereas BPD in recent era is caused by impaired pulmonary angiogenesis and alveolarization in extreme prematurity. Although sildenafil was reported to be effective in a hyperoxia-induced rat BPD model, several clinical trials could not demonstrate any significant improvement in the respiratory statuses of BPD infants. Riociguat is a soluble guanylate cyclase stimulator that increases cyclic guanosine monophosphate activity in a nitric oxide independent manner. However, a beneficial effect in BPD has not been established yet. METHODS AND RESULTS: We established BPD model in rats by injection of SU5416 on day 1 followed by maintenance under normoxia, which resulted in oversimplified alveoli, sparse pulmonary capillary vessels, severe pulmonary hypertension, and growth retardation, which mimicked the features observed in recent clinical management of BPD. We administered riociguat from day 10, when BPD rats exhibited growth retardation. Histological analyses demonstrated that riociguat treatment significantly but partially ameliorated lung alveolarization, vascularization, and pulmonary hypertension. However, the survival rate was not significantly improved by riociguat treatment. CONCLUSIONS: Riociguat could ameliorate pulmonary alveolarization, vascularization, and hypertension in the SU5416 induced BPD rat model, but could not improve the overall survival.

Diagnostic value of P-waves in children with idiopathic restrictive cardiomyopathy.

Restrictive cardiomyopathy (RCM) is a rare myocardial disease with an impaired diastolic function and poor prognosis. Almost all RCM patients are reported to have abnormal P-waves due to atrial overloading. This study aimed to reveal the characteristics of the P-waves in RCM patients and to suggest the diagnostic index of RCM in children with a 12-lead electrocardiogram (ECG). We retrospectively investigated 17 ECGs of children with idiopathic RCM during the initial visit at 15 institutes in Japan between 1979 and 2013. The RCM group was divided into four groups based on the age (elementary school [ES] and junior high school [JHS] students) and inception of the diagnosis (abnormal ECG on school-heart-screening [e-RCM] and some cardiovascular symptoms [s-RCM]), the ES/e-RCM (n = 5), ES/s-RCM (n = 4), JHS/e-RCM (n = 4), and JHS/s-RCM (n = 4) groups. As an aged-match control group, school-heart-screening ECGs of 1st-grade ES students (16,770 students) and 1st-grade JHS students (18,126 students) from Kagoshima in 2016 were adopted. For a comparison between the groups, we used the effect size "Hedge's g" by calculating the mean and standard deviation of the two groups. An effect size of 0.8 (or above) had an overlap of 53% (or less). The effect sizes of the sum of the absolute values of the forward and backward amplitudes in lead V1 (P1 + P2 V1) was the largest, and the ES/e-RCM, ES/s-RCM, JHS/e-RCM, and JHS/s-RCM were 15.8, 22.1, 9.4, and 10.3, respectively. A P1 + P2 V1 > 200 µV was able to rule in all RCM patients, thus, we proposed 200 µV as the cutoff value for screening purposes. In conclusion, the P1 + P2 V1 in the school-heart-screening may be useful for detecting asymptomatic or early-stage RCM in school-age children.

A significance of school screening electrocardiogram in the patients with ventricular noncompaction.

Left ventricular noncompaction (LVNC) is a hereditary cardiomyopathy and is associated with high morbidity and mortality. However, the role and significance of school screening for LVNC have not been fully elucidated. In this multicenter, retrospective cohort study, a total of 105 children with LVNC were included from 2000 to 2017. At the initial presentation, 44 patients (41.9%) were diagnosed by school screening. One (1.0%) patient underwent heart transplantation and four (3.8%) patients died during the study. Electrocardiogram data showed a high prevalence of fragmented QRS (33.4%) and J wave (15.7%). Treatments were needed in eight (18.2%) patients who were detected by school screening. The multivariable proportional hazards model showed T-wave abnormality on electrocardiogram in first graders was independent risk factors for major adverse cardiac events (odds ratio 4.94, p value = 0.0007). Moreover, dilation of the left atrium on chest X-ray and low ejection fraction on echocardiogram at the initial treatment were independent risk factors for treatment (odds ratio 1.7 × 107 and 22.3, p = 0.0362 and 0.0028, respectively). This study is the first report focusing on school screening in a large pediatric cohort with LVNC. With the use of abnormalities in electrocardiogram, school screening may be a good detector of and predictor for LVNC.

Detection of Pediatric Pulmonary Arterial Hypertension by School Electrocardiography Mass Screening.

Rationale: To detect pulmonary arterial hypertension (PAH) at any early stage is a promising approach to optimize the outcome. Objectives: To investigate the impact of school ECG-based screening on detecting idiopathic or heritable (I/H)-PAH in the general pediatric population. Methods: This was a nationwide survey of patients with I/H-PAH newly diagnosed at 3 months to 18 years of age in Japan during 2005-2012. Measurements and Main Results: Eighty-seven eligible patients (age range, 1-16 yr) were recruited. Among 68 (78%) patients diagnosed at greater than or equal to 6 years of age (the age of the first ECG-based screening), 28 (41%) were detected by the ECG-based screening (screening group) and 40 (59%) were recognized by their symptoms (n = 37) or coincidental occasions (n = 3; nonscreening group). In the screening group, the proportion of patients in World Health Organization functional class I/II at diagnosis was higher (96% vs. 60%; P < 0.001), plasma brain natriuretic peptide level was lower (149 ± 290 vs. 398 ± 559 pg/ml; P = 0.045), and 6-minute-walk distance was longer (420 ± 109 vs. 327 ± 104 m; P < 0.001) than the nonscreening group, despite similar values in mean pulmonary artery pressure (58 ± 17 vs. 61 ± 17 mm Hg; P = 0.42) and pulmonary vascular resistance index (18 ± 8 vs. 21 ± 11 Wood units ⋅ m2; P = 0.24) between groups. The proportion of patients on intravenous epoprostenol at the final visit was lower in the screening group than the nonscreening group (14% vs. 50; P = 0.004). Conclusions: These findings suggest that the ECG-based screening detects a unique subpopulation of pediatric patients with I/H-PAH that is associated with already established pulmonary hypertension but without obvious right heart failure and warrants investigating the prognostic significance of this system.

Prognostic predictive value of gene mutations in Japanese patients with hypertrophic cardiomyopathy.

Although some studies have attempted to find useful prognostic factors in hypertrophic cardiomyopathy (HCM), those results are not fully helpful for use in actual clinical practice. Furthermore, several genetic abnormalities associated with HCM have been identified. However, the genotype-phenotype correlation in HCM remains to be elucidated. Here, we attempted to assess patients with different types of gene mutations causing HCM and investigate the prognosis. A total of 140 patients with HCM underwent a screening test for myofilament gene mutations by direct sequencing of eight sarcomeric genes. Patients with a single mutation in cardiac troponin T, cardiac troponin I, α-tropomyosin, and regulatory and essential light chains were excluded from the study because the number of cases was too small. The clinical presentations and outcomes of the remaining 127 patients with HCM, 31 ß-myosin heavy chain (MYH7) mutation carriers, 19 cardiac myosin-binding protein C (MYBPC3) mutation carriers, and 77 mutation non-carriers were analyzed retrospectively. MYBPC3 mutation carriers had a high frequency of ventricular arrhythmia and syncope. Kaplan-Meier curves revealed no significant difference in prognosis among the three groups, but a lack of family history of sudden death (SD) and a past history of syncope were significantly related to poor prognosis. An absence of family history of SD and past history of syncope are useful prognostic factors in patients with HCM. MYH7 and MYBPC3 mutations did not significantly influence prognosis compared to non-carriers. However, patients with the MYBPC3 mutation should be closely followed for the possibility of SD.

Generation of Induced Pluripotent Stem Cells From Patients With Duchenne Muscular Dystrophy and Their Induction to Cardiomyocytes.

Duchenne muscular dystrophy (DMD) is caused by mutations in the DMD gene which encodes dystrophin protein. Dystrophin defect affects cardiac muscle as well as skeletal muscle. Cardiac dysfunction is observed in all patients with DMD over 18 years of age, but there is no curative treatment for DMD cardiomyopathy. To establish novel experimental platforms which reproduce the cardiac phenotype of DMD patients, here we established iPS cell lines from T lymphocytes donated from two DMD patients, with a protocol using Sendai virus vectors. We successfully conducted the differentiation of the DMD patient-specific iPS cells into beating cardiomyocytes. DMD patient-specific iPS cells and iPS cell-derived cardiomyocytes would be a useful in vitro experimental system with which to investigate DMD cardiomyopathy.

Drastic shift from positive to negative estrogen effect on bone morphogenetic protein signaling in pulmonary arterial endothelial cells under hypoxia.

BACKGROUND: To investigate the possible role of sex hormones in the pathogenesis of pulmonary arterial hypertension (PAH), the effect of ß-estradiol (E2) on bone morphogenetic protein (BMP) signaling, a key signaling pathway involved in PAH, was studied in human pulmonary arterial endothelial cells (HPAEC). METHODS AND RESULTS: BMP signaling molecules, including BMP receptor, Smad1/5/8 and Id1, were studied in HPAEC under 1% O2 (hypoxia) and 21% O2 (normoxia) as well as the effect of hypoxia-inducible factor (HIF)-1α expression in the presence of E2 on BMP signaling. The effects of an estrogen receptor (ER) antagonist (ICI 182,780) and cycloheximide, and the interaction of ER with Smad or HIF-1α were also studied. In the presence of E2, BMP signaling was augmented under normoxia but suppressed under hypoxia. HIF-1α accumulation suppressed BMP signaling, whereas HIF-1α inhibition augmented signaling. These effects were cancelled by ICI 182,780. Moreover, binding between ER, HIF-1α and phosphorylated (p)-Smad1/5/8 proteins occurred only under hypoxia. On inhibition of de novo synthesis with cycloheximide, however, p-Smad1/5/8 expression was suppressed only under normoxia. CONCLUSIONS: The effects of E2 on BMP signaling in HPAEC altered depending on O2 concentration and different mechanisms may be involved. BMP and sex hormones may play an important role in PAH development.

Clinical Outcomes and Genetic Analyses of Restrictive Cardiomyopathy in Children.

BACKGROUND: Restrictive cardiomyopathy in children is rare and outcomes are very poor. However, little information is available concerning genotype-outcome correlations. METHODS: We analyzed the clinical characteristics and genetic testing, including whole exome sequencing, of 28 pediatric restrictive cardiomyopathy patients who were diagnosed from 1998 to 2021 at Osaka University Hospital in Japan. RESULTS: The median age at diagnosis (interquartile range) was 6 (2.25-8.5) years. Eighteen patients received heart transplantations and 5 patients were on the waiting list. One patient died while waiting for transplantation. Pathologic or likely-pathogenic variants were identified in 14 of the 28 (50%) patients, including heterozygous TNNI3 missense variants in 8 patients. TNNT2, MYL2, and FLNC missense variants were also identified. No significant differences in clinical manifestations and hemodynamic parameters between positive and negative pathogenic variants were detected. However, 2- and 5-year survival rates were significantly lower in patients with pathogenic variants (50% and 22%) compared with survival in patients without pathogenic variants (62% and 54%; P=0.0496, log-rank test). No significant differences were detected in the ratio of patients diagnosed at nationwide school heart disease screening program between positive and negative pathogenic variants. Patients diagnosed by school screening showed better transplant-free survival compared with patients diagnosed by heart failure symptoms (P=0.0027 in log-rank test). CONCLUSIONS: In this study, 50% of pediatric restrictive cardiomyopathy patients had pathogenic or likely-pathogenic gene variants, and TNNI3 missense variants were the most frequent. Patients with pathogenic variants showed significantly lower transplant-free survival compared with patients without pathogenic variants.

Pediatric Advance Care Planning for a Patient with a Severe Motor and Intellectual Disorder through Cooperation between an Acute Care Hospital and a Residential Facility.

Background: With the rapid progress of medical technology, the number of children with medical complexities who require advanced medical care, including mechanical ventilators, has been increasing steadily in Japan. Accordingly, the issue of how to provide holistic care and support for the entire life of the children with severe motor and intellectual disabilities (SMID) who live at home has become a new challenge. Case Presentation: We present the case of a three-year-old boy with SMID due to HHV-6B-induced hemorrhagic shock encephalopathy who was cared for at home by the home visit medical team of Osaka Developmental Rehabilitation Center (ODRC; residential facilities with the department of home medical treatment and care). He developed septic shock triggered by an urinary tract infection and was admitted to Osaka General Medical Center (OGMC; acute care facility not directly affiliated with ODRC), where he deteriorated to a terminal stage. After discussing advance care planning (ACP) with his parents, along with the medical team, an ACP document with parental wishes was created through collaboration between the two facilities. The document was approved by the Ethics Committee at OGMC and the parents signed the document. Special end-of-life care planning was given by nurses at OGMC based on the best interests of the patient and the family. The patient passed away peacefully surrounded by his family in a private room of OGMC according to the ACP, despite special limitations caused by the coronavirus disease 2019 (COVID-19) pandemic. Conclusions: ACP provides a good opportunity to think about the best total care for a child with SMID, for whom it is too difficult to express his or her wishes, together with the parents, who are the legal representatives. The collaboration between two institutions with different roles brought out the best of each, and the resulting ACP was beneficial to the patient and their family.