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Iroquois homeobox (Irx) genes are TALE-class homeobox genes that are evolutionarily conserved across species and have multiple critical cellular functions in fundamental tissue development processes. Previous studies have shown that Irxs genes are expressed during tooth development. However, the precise roles of genes in teeth remain unclear. Here, we demonstrated for the first time that Irx3 is an essential molecule for the proliferation and differentiation of odontoblasts. Using cDNA synthesized from postnatal day 1 (P1) tooth germs, we examined the expression of all Irx genes (Irx1-Irx6) by RT-PCR and found that all genes except Irx4 were expressed in the tooth tissue. Irx1-Irx3 a were expressed in the dental epithelial cell line M3H1 cells, while Irx3 and Irx5 were expressed in the dental mesenchymal cell line mDP cells. Only Irx3 was expressed in both undifferentiated cell lines. Immunostaining also revealed the presence of IRX3 in the dental epithelial cells and mesenchymal condensation. Inhibition of endogenous Irx3 by siRNA blocks the proliferation and differentiation of mDP cells. Wnt3a, Wnt5a, and Bmp4 are factors involved in odontoblast differentiation and were highly expressed in mDP cells by quantitative PCR analysis. Interestingly, the expression of Wnt5a (but not Wnt3a or Bmp4) was suppressed by Irx3 siRNA. These results suggest that Irx3 plays an essential role in part through the regulation of Wnt5a expression during odontoblast proliferation and differentiation.

The prospective Control of HEART rate in inFant and child tachyarrhythmia with reduced cardiac function Using Landiolol (HEARTFUL) study investigated the effectiveness and safety of landiolol, a short-acting βThe HEARTFUL study has demonstrated the efficacy of landiolol, by reducing heart rate or terminating tachycardia, in pediatric patients with supraventricular tachyarrhythmias. Although serious ARs and concerns were not identified in this study, physicians should be always cautious of circulatory collapse due to hypotension.

The left ventricular (LV) apex is recommended as the first choice for positioning the epicardial pacing. We encountered a patient with congenital heart disease (CHD) showing hypokinesis of the LV apical pacing site after implantation of a pacemaker with epicardial leads. This phenomenon was revealed by the early shortening and systolic rebound stretch of the same lesion on two-dimensional speckle tracking echocardiography, which developed in the intraventricular dyssynchrony between the LV apex and base. Cardiac resynchronization therapy provided an excellent result around the hypokinetic lesion. It is wise to arrange detailed evaluations in each patient with complicated CHD, aiming at a successful treatment to enable ventricular synchronicity.

A high prevalence of heavy menstrual bleeding (HMB) has been reported in women with Fontan circulation. Cyanosis has been reported to contribute to HMB, and menstruation has been suggested to affect cardiac status in women with congenital heart disease. This study aimed to evaluate the relationship between the amount of menstrual flow and cardiac status in women with Fontan circulation.Twenty women who had undergone the Fontan procedure were prospectively investigated and the amount of their menstrual flow was evaluated using a questionnaire. Participants were divided into two groups-small and large menstrual bleeding groups-and their clinical data, including the results of hematological tests and echocardiographic findings, were evaluated.One (5%) woman showed primary amenorrhea. Eight of the remaining 19 (42%) women were included in the large menstrual bleeding group. Women with large menstrual bleeding showed a significantly higher hematocrit level (47.1% [36.2%-50.3%] versus 42.1% [35.3%-44.9%], P = 0.006) and longer QRS duration (106 [92-172] ms versus 88 [78-140] ms, P = 0.008), as well as a lower fractional area change (37.4% [35.6%-47.2%] versus 47.0% [38.2%-55.7%], P = 0.010) and global longitudinal strain (-10.5% [-14.9% to -6.6%] versus -13.9% [-20.5% to -7.8%], P = 0.041) of the dominant ventricle on echocardiography, than women with small bleeding.Erythrocytosis, longer QRS duration, and reduced ventricular function were related to increased menstrual bleeding in women with Fontan circulation. These functions may be interrelated with the amount of menstrual flow in such women.

The usefulness of a treadmill exercise test for determining optimal pacemaker settings remains unknown. An 8-year-old boy with Fontan circulation and a dual-chamber pacemaker for a rate-dependent advanced atrioventricular block suffered from dullness and poor school attendance. Although the pacemaker log showed an atrial tachycardia/fibrillation episode, treadmill exercise testing revealed sinus tachycardia, which converted to a 2:1 atrioventricular block. The pacemaker setting was optimized, with improvement in the patient's condition.Treadmill exercise testing helps optimize dual-chamber pacemaker settings in children with complex congenital heart disease involved in energy-consuming physical activities and having a wide working range in sinus rate.

Guidelines for the implantation of cardiac implantable electronic devices (CIEDs) have evolved since publication of the initial ACC/AHA pacemaker guidelines in 1984 [ 1 ]. CIEDs have evolved to include novel forms of cardiac pacing, the development of implantable cardioverter defibrillators (ICDs) and the introduction of devices for long term monitoring of heart rhythm and other physiologic parameters. In view of the increasing complexity of both devices and patients, practice guidelines, by necessity, have become increasingly specific. In 2018, the ACC/AHA/HRS published Guidelines on the Evaluation and Management of Patients with Bradycardia and Cardiac Conduction Delay [ 2 ], which were specific recommendations for patients >18 years of age. This age-specific threshold was established in view of the differing indications for CIEDs in young patients as well as size-specific technology factors. Therefore, the following document was developed to update and further delineate indications for the use and management of CIEDs in pediatric patients, defined as ≤21 years of age, with recognition that there is often overlap in the care of patents between 18 and 21 years of age. This document is an abbreviated expert consensus statement (ECS) intended to focus primarily on the indications for CIEDs in the setting of specific disease/diagnostic categories. This document will also provide guidance regarding the management of lead systems and follow-up evaluation for pediatric patients with CIEDs. The recommendations are presented in an abbreviated modular format, with each section including the complete table of recommendations along with a brief synopsis of supportive text and select references to provide some context for the recommendations. This document is not intended to provide an exhaustive discussion of the basis for each of the recommendations, which are further addressed in the comprehensive PACES-CIED document [ 3 ], with further data easily accessible in electronic searches or textbooks.