Correction to: Clinical Effects of Syncope on Disease Severity and Adverse Outcomes in Children with Idiopathic and Heritable Pulmonary Arterial Hypertension.

The original version of this article unfortunately contained a mistake in the author name. The co-author name should be Hiroyuki Matsuura instead of Horoyuki Matsuura. The original article has been corrected.

Clinical Effects of Syncope on Disease Severity and Adverse Outcomes in Children with Idiopathic and Heritable Pulmonary Arterial Hypertension.

Syncope is more common in children with idiopathic pulmonary arterial hypertension (PAH) than in adults with PAH. Although syncope is associated with a poor prognosis in adult PAH, the clinical effects of syncopal events on disease severity and outcome in children have not been carefully investigated. This study assessed the prevalence of syncope in pediatric PAH and examined its clinical, hemodynamic, and prognostic importance. This retrospective study assessed clinical data, including syncope status, from 78 children (37 girls) with idiopathic and heritable PAH (median age at diagnosis, 11 years). Patients were classified as syncopal or non-syncopal, and clinical data from the two groups were compared. The primary outcome was a composite of lung transplantation and cardiac mortality. Overall, 31 (38%) children had a history of syncope at presentation. Median age at diagnosis, sex ratio, brain natriuretic peptide level, and 6-min walk distance at diagnosis did not differ between groups. The hemodynamic parameters of initial right heart catheterization were similar between the syncope and non-syncope group (mean pulmonary artery pressure, 67 versus 71 mm Hg; cardiac index, 2.9 versus 2.9 l/min/m2, respectively). There was not significantly difference in event-free survival rate between two groups. Although syncopal events are common in children with PAH, our findings suggest that syncope may not be correlated with disease severity or outcome in pediatric PAH.

Apparent nonlinear damping triggered by quantum fluctuations.

Nonlinear damping, the change in damping rate with the amplitude of oscillations plays an important role in many electrical, mechanical and even biological oscillators. In novel technologies such as carbon nanotubes, graphene membranes or superconducting resonators, the origin of nonlinear damping is sometimes unclear. This presents a problem, as the damping rate is a key figure of merit in the application of these systems to extremely precise sensors or quantum computers. Through measurements of a superconducting resonator, we show that from the interplay of quantum fluctuations and the nonlinearity of a Josephson junction emerges a power-dependence in the resonator response which closely resembles nonlinear damping. The phenomenon can be understood and visualized through the flow of quasi-probability in phase space where it reveals itself as dephasing. Crucially, the effect is not restricted to superconducting circuits: we expect that quantum fluctuations or other sources of noise give rise to apparent nonlinear damping in systems with a similar conservative nonlinearity, such as nano-mechanical oscillators or even macroscopic systems.

Treatment strategy for pediatric giant mucinous cystadenoma: A case report.

Because of their rarity, the treatment strategy for pediatric ovarian epithelial tumors is controversial, especially for a giant cystadenoma. We report the largest mucinous cystadenoma (MCA) case in the pediatric literature thus far. A 12-year-old girl had abdominal distention and visited our hospital. She had a multilocular cyst with some protuberance on the inside and high values of CA 19-9 and CA-125. We diagnosed her with a left MCA and performed a left oophorectomy. The tumor was the stage IA borderline malignant MCA and weighed 11.8 kg. Five years have passed, the patient has not experienced recurrence or metastasis. The resection of giant tumors can affect respiration and circulation. However, pre- or intra-operative drainage may lead to dissemination and adhesion. When we treat pediatric giant ovarian epithelial tumors, we must understand the findings that suggest the possibility of malignancy to decide appropriately as to whether drainage should be performed.

Implication of overexpression of dishevelled-associated activator of morphogenesis 1 (Daam-1) for the pathogenesis of human Idiopathic Pulmonary Arterial Hypertension (IPAH).

BACKGROUND: Idiopathic pulmonary arterial hypertension (IPAH) is a rare, fatal disease of unknown pathogenesis. Evidence from our recent study suggests that IPAH pathogenesis is related to upregulation of the Wnt/planar cell polarity (Wnt/PCP) pathway. We used microscopic observation and immunohistochemical techniques to identify expression patterns of cascading proteins-namely Wnt-11, dishevelled-2 (Dvl-2), and dishevelled-associated activator of morphogenesis 1 (Daam-1)-in pulmonary arteries. METHODS: We analyzed sections of formalin-fixed and paraffin-embedded autopsied lung tissues obtained from 9 IPAH cases, 7 associated pulmonary arterial hypertension cases, and 16 age-matched controls without pulmonary arterial abnormalities. Results of microscopic observation were analyzed in relation to the cellular components and size of pulmonary arteries. RESULTS: Varying rates of positive reactivity to Dvl-2 and Daam-1 were confirmed in all cellular components of pulmonary arteries, namely, endothelial cells, myofibroblasts, and medial smooth muscle cells. In contrast, none of these components was reactive to Wnt-11. No specific expression patterns were observed for endothelial cells or myofibroblasts under any experimental conditions. However, marked expression of Dvl-2 and Daam-1 was confirmed in smooth muscle cells. In addition, Dvl-2 was depleted while Daam-1 expression was elevated in IPAH, in contrast with specimens from associated pulmonary arterial hypertension cases and controls. CONCLUSIONS: High Daam-1 expression may upregulate the Wnt/PCP pathway and cause IPAH.