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Pulmonary arterial hypertension (PAH) is a severe disease characterized by sustained vasoconstriction, concentric wall thickening and vascular remodeling leading to increased pulmonary vascular resistance, causing right heart failure and death. Acute alveolar hypoxia causes pulmonary vasoconstriction, while sustained hypoxia causes pulmonary hypertension (PH). Activation of Notch signaling is implicated in the development of PAH and chronic hypoxia induced PH via partially its enhancing effect on Ca

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a rare genetic disease that is characterized by ventricular arrhythmias and sudden death, induced by exogenous and endogenous catecholamine. We performed general anesthesia for dental treatment of multiple teeth in a 7-year-old boy with CPVT. To avoid sympathetic tone, anesthesia was maintained by total intravenous anesthesia, but ventricular bigeminy was induced by stimulation on emergence form general anesthesia. Although bigeminy in the present case might have been less likely to induce a fatal arrhythmia, we should keep in mind that a small amount of sympathetic tone may induce arrhythmias in a patient with CPVT.

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.

Background Abnormal endothelial function in the lungs is implicated in the development of pulmonary hypertension; however, there is little information about the difference of endothelial function between small distal pulmonary artery (PA) and large proximal PA and their contribution to the development of pulmonary hypertension. Herein, we investigate endothelium‐dependent relaxation in different orders of PAs and examine the molecular mechanisms by which chronic hypoxia attenuates endothelium‐dependent pulmonary vasodilation, leading to pulmonary hypertension. Methods and Results Endothelium‐dependent relaxation in large proximal PAs (second order) was primarily caused by releasing NO from the endothelium, whereas endothelium‐dependent hyperpolarization (EDH)–mediated vasodilation was prominent in small distal PAs (fourth–fifth order). Chronic hypoxia abolished EDH‐mediated relaxation in small distal PAs without affecting smooth muscle–dependent relaxation. RNA‐sequencing data revealed that, among genes related to EDH, the levels of Cx37 , Cx40 , Cx43 , and IK were altered in mouse pulmonary endothelial cells isolated from chronically hypoxic mice in comparison to mouse pulmonary endothelial cells from normoxic control mice. The protein levels were significantly lower for connexin 40 (Cx40) and higher for connexin 37 in mouse pulmonary endothelial cells from hypoxic mice than normoxic mice. Cx40 knockout mice exhibited significant attenuation of EDH‐mediated relaxation and marked increase in right ventricular systolic pressure. Interestingly, chronic hypoxia led to a further increase in right ventricular systolic pressure in Cx40 knockout mice without altering EDH‐mediated relaxation. Furthermore, overexpression of Cx40 significantly decreased right ventricular systolic pressure in chronically hypoxic mice. Conclusions These data suggest that chronic hypoxia‐induced downregulation of endothelial Cx40 results in impaired EDH‐mediated relaxation in small distal PAs and contributes to the development of pulmonary hypertension.

Introduction: The abnormal proliferation of pulmonary arterial smooth muscle cells (PASMCs) is one of pathological characteristics of pulmonary arterial hypertension (PAH). Inflammation is thought to play an important role for PASMCs proliferation in PAH. Dexmedetomidine (DEX) is a selective α2-adrenergic receptor agonist that is used as a sedative in clinical settings. It has been reported that DEX regulates certain inflammatory responses. Hypothesis: DEX ameliorates Monocrotaline (MCT)-induced PAH in rats through its anti-inflammatory effect. Methods: In vivo, 6-week-old male Sprague-Dawley rats were injected 60 mg/kg of MCT subcutaneously. At day 14 after MCT injection, continuous infusions of DEX (2μg/kg/hour) by osmotic pumps were started in one group (MCT + DEX group), and not in another group (MCT group). We performed cardiac catheterization to measure right ventricular systolic pressure (RVSP) and prepared rats paraffin embedded lung tissues for Immunohistochemistry at day 23. In vitro, we analyzed the effect of DEX on human PASMCs (hPASMCs) proliferation stimulated with fibroblast growth factor 2 (FGF2). In addition, we examined mRNA levels of proinflammatory cytokines in hPASMCs by FGF2 stimuation with/without DEX. Results: Both RVSP and survival rate markedly improved in MCT + DEX group compared with those in MCT group (RVSP; 34mmHg ± 4mmHg vs. 70mmHg ± 10mmHg, survival rate 42% vs. 0% at day 29). In histological analysis, medial hypertrophy of pulmonary arterioles and phosphorylated-p65 positive PASMCs significantly reduced in MCT + DEX group. DEX also inhibited hPASMCs proliferation dose dependently. Furthermore, IL-6 mRNA expression was suppressed by DEX in hPASMCs stimulated with FGF2. Conclusions: DEX improved MCT-induced PAH in rats by suppressing PASMCs proliferation through the anti-inflammatory effect, which may result from inhibition of NF-κB activation induced by IL-6. DEX can be a new therapeutic tool for PAH.

10q26 deletion syndrome is caused by a rare chromosomal abnormality, and patients with this syndrome present with an extensive and heterogeneous phenotypic spectrum. Several genes, such as EMX2 and FGFR2, were identified as the cause genital anomalies and facial dysmorphism in 10q26 deletion syndrome. However, the critical region for 10q26 deletion syndrome is not determined and the precise relationships between the causative genes and the phenotypes are still controversial. WD repeat domain 11 (WDR11), located at 10q25–26, was recently identified as a causative gene in hypogonadotropic hypogonadism, but other clinical phenotypes caused by WDR11 variants have not been identified. In this study, we have identified a WDR11 missense mutation, NM_018117.11: c.2108G > A; p.(Arg703Gln); ClinVar accession SCV000852064, in a two-year-old boy with severe growth retardation, ventricular septal defect, and coloboma symptoms. The case suggests that WDR11 is partially responsible for the clinical features of 10q26 deletion syndrome and provides novel insights into the pathophysiology of this syndrome.

Aims Proliferation of pulmonary arterial smooth muscle cells (PASMCs) is one histological sign of pulmonary arterial hypertension (PAH). We hypothesized that a signalling cascade from fibroblast growth factor 2 (FGF2) to plasminogen activator inhibitor 1 (PAI-1) and monocyte chemotactic protein-1 (MCP-1) via nuclear transcription factor nuclear factor kappaB (NF-kB) play a critical role in progression of PAH, and tested this hypothesis both in vivo and in vitro using a synthetic selective NF-kB inhibitor, N -(3,5-Bis-trifluoromethyl-phenyl)-5-chloro-2-hydroxy-benzamide (IMD-0354). Methods and results Monocrotaline (MCT) was injected into 75 Sprague–Dawley rats. Starting at day 14 after MCT injection, we administered IMD-0354 (MCT + IMD group) or vehicle (MCT group) daily. At day 32, 65% of the MCT + IMD group were alive compared with 0% of the MCT group. IMD-0354 prevented increase of right ventricular pressure, and suppressed proliferation and induced apoptosis of PASMCs. mRNA transcript levels of FGF2, PAI-1, and tissue plasminogen activator (t-PA) were lower in MCT + IMD compared with MCT. In in vitro experiments, IMD-0354 inhibited p65 translocation to the nucleus promoted by FGF2 in PASMCs. Furthermore, the time courses of extracellular signal-regulated kinase (Erk) 1/2, MCP-1, and PAI-1 stimulated with FGF2 were each markedly shortened by IMD-0354. Conclusions We speculate that the positive-feedback loop (Erk1/2–NF-kB–MCP-1–Erk1/2) is associated with progression of PAH by causing FGF2-induced inflammation in MCT rats. IMD-0354 has potential as a new therapeutic tool for PAH.

We report a case of anomalous origin of the left main coronary artery (LCA) from the noncoronary sinus of valsalva (LCANCS) in a young healthy patient who presented with syncope and cardiopulmonary arrest during exercise. The enhanced computed tomography showed acute angle take-off (AAT) of LCA, and the exercise stress thallium-201 myocardial scintigraphy demonstrated a large defect at the LCA perfusion region. We propose that the coexistence of AAT and resulting ischemia causes sudden cardiac death during exercise in the patients with LCANCS.

To assess the safety and efficacy of infliximab (IFX) for the treatment of patients with Kawasaki disease (KD).This was a nationwide survey of 274 Japanese institutions exploring how IFX was used to treat patients with KD. The patients' sex, age, treatment course, pre- and post-IFX therapy blood test results, coronary artery lesions (CALs), and adverse events (AEs) were evaluated.We analyzed 434 patients with KD who received IFX between March 2005 and November 2014. The median age at onset was 33 months (range 1-138), and 66 patients (15.2%) were under 1 year old. In all cases, IFX was administered as additional treatment. The median days of illness at the initiation of IFX was 9 days. In 275 patients (63.4%), IFX was administered as third-line treatment, and in 106 patients (24.4%), IFX was administered as fourth-line treatment. Single dose IFX 5 mg/kg was administered to 412 patients (94.9%). After IFX, 363 patients (83.6%) became afebrile within 2 days, and the white blood cell count, percentage of neutrophils, and serum C-reactive protein levels significantly decreased (P .001), although 119 patients (27.4%) received additional treatment. Before IFX, 132 patients (30.4%) had already developed CALs. In patients without CALs before IFX, 31 patients (10.3%) newly developed CAL after IFX, whereas 32 patients (24.2%) with CAL before IFX showed increased CAL severity. Eighty AEs were observed in 69 patients (15.9%); however, serious AEs were few and reversible.IFX might be an effective and tolerable treatment for refractory KD.

[Introduction] Pulmonary arterial hypertension (PAH) is characterized by increased proliferation and apoptosis resistance of pulmonary arterial smooth muscle cells (PASMCs). Dexmedetomidine (DEX) is a selective α2-aderenergic receptor agonist that is used for sedation in clinical practice. It has been reported that DEX inhibits inflammatory responses through cytokines, such as TNF-alpha, IL-6. Furthermore other reports show that G-protein-coupled receptors (GPCRs) are regulated by β-arrestins, which are also involved with inflammation. [Hypothesis] DEX ameliorates monocrotaline (MCT)-induced PAH in rats by its anti-inflammatory effect. [Methods] We treated 6 weeks-old male Sprague-Dawley rats with a single 60mg/kg intraperitoneal injection of MCT. After 14 days of injection, one group of rats was started to administer dexmedetomidine (dose: 2μg/kg/hour, MCT+DEX group) continuously using osmotic pumps, the other group was not treated with DEX (MCT group). We performed physiological examination and cardiac catheterization to measure right ventricular systolic pressure (RVSP) at day 23. [Results] Both RVSP and survival rate of rats in MCT+DEX group markedly improved compared with those in MCT group (RVSP; 38mmHg±11mmHg vs 91mmHg±6mmHg, survival rate; 42% vs 0% at day 30). In histological analysis, DEX reduced the medial hypertrophy of pulmonary arterioles, and decreased phosphorylated-NF-kB p65 (p-p65) positive PASMCs in MCT+DEX group compared with those of MCT group. In addition, DEX suppressed PASMCs proliferation with PCNA staining, and induced apoptosis of PASMCs with TUNEL assay. Then we examined the involvement of β-arrestins in PAH. It showed that βarrestin1 expressions reduced in MCT group compared with that of MCT+DEX group with western blotting and immunohistochemistry. However β-arrestin2 expressions had no significant difference between the two groups. [Conclusions] DEX ameliorates MCT-induced PAH in rats, one of the mechanism of which may be NF-kB inhibition through β-arrestin1. DEX can be a new therapeutic tool for PAH.

Introduction: A growing body of evidence suggests that inflammation plays a crucial role in the development of pulmonary arterial hypertension (PAH). Dipeptidyl peptidase-4 (DPP-4; also known as CD26), a protease which degrades incretin hormones such as glucagon-like peptide-1 (GLP-1), modulates inflammatory processes by regulating activity of T cells through co-stimulatory pathway. Hypothesis: Incretin-related drugs, including both DPP-4 inhibitors and GLP-1 receptor agonists, suppress the progression of PAH by attenuating inflammatory response of PA. Methods: Sprague Dawley rats were injected monocrotaline to induce PAH (N=80). After 14 days from PAH induction, these rats were treated with alogliptin, a DPP-4 inhibitor (M+A, N=20), liraglutide, a GLP-1 receptor agonist (M+L, N=20), both of these drugs (M+A+L, N=20), or vehicle (M, N=20). Results: A significant increase of survival was observed on days 30 after PAH induction both in the M+A and M+L compared to the M (M+A: 45%* vs. M+L: 60%* vs. M: 5%, * p vs. M+L: 26±1.9mmHg* vs. M: 85.9±1.2mmHg, * p and the level of caveolin-1 markedly increased in lung tissues of the M+A compared to those in the M. mRNA levels of both Tissue Factor (TF) and PAI-1 significantly decreased in lung tissues of the M+L than those in the M. Consistently, survival of rats in the M+A+L was the highest (65%) among all of the groups of PAH rats. Coimmunoprecipitation assays revealed that CD26 in T cells physically interacted with caveolin-1 in rat pulmonary vascular smooth muscle cells (rPASMCs). Immunoblot analyses showed that alogliptin suppressed caveolin-1 phosphorylation in rPASMCs. Furthermore, reporter gene assays demonstrated that alogliptin significantly inhibited the transcriptional activity of NF-κB. Conclusions: These results suggest that DPP-4 inhibition and stimulation of GLP-1 receptors synergistically mediate salutary effects on monocrotaline-induced PAH by modulating T cell activity and TF-associated signaling pathway. Thus, incretin-related drugs have a potential as a novel therapeutic tool for PAH.