Left-right (L-R) asymmetries in neuroanatomy exist throughout the animal kingdom, with implications for function and behavior. The molecular mechanisms that control formation of such asymmetries are beginning to be understood. Significant progress has been made by studying the zebrafish parapineal organ, a group of neurons on the left side of the epithalamus. Parapineal cells arise from the medially located pineal complex anlage and migrate to the left side of the brain. We have found that Fgf8a regulates a fate decision among anterior pineal complex progenitors that occurs just prior to the initiation of leftward migration. Cell fate analysis shows that in the absence of Fgf8a a subset of cells in the anterior pineal complex anlage differentiate as cone photoreceptors rather than parapineal neurons. Fgf8a acts permissively to promote parapineal fate in conjunction with the transcription factor Tbx2b, but might also block cone photoreceptor fate. We conclude that this subset of anterior pineal complex precursors, which normally become parapineal cells, are bipotential and require Fgf8a to maintain parapineal identity and/or prevent cone identity.

Purpose of Review While there have now been a variety of large reviews on adult pericarditis, this detailed review specifically focuses on the epidemiology, clinical presentation, diagnosis, and management of pediatric pericarditis. We have tried to highlight most pediatric studies conducted on this topic, with special inclusion of important adult studies that have shaped our understanding of and management for acute and recurrent pericarditis. Recent Findings We find that the etiology of pediatric pericarditis differs from adult patients with pericarditis and has evolved over the years. Also, with the current COVID-19 pandemic, it is important for pediatric clinicians to be aware of pericardial involvement both due to the infection and from vaccination. Oftentimes, pericarditis maybe the only cardiac involvement in children with COVID-19, and so caregivers should maintain a high index of suspicion when they encounter children with pericarditis. Summary Large-scale contemporary epidemiological data regarding incidence and prevalence of both acute and recurrent pericarditis is lacking in pediatrics, and future studies should focus on highlighting this important research gap. Most of the current management strategies for pediatric pericarditis are from experiences gathered from adult data. Pediatric multicenter trials are warranted to understand the best management strategy for those with acute and recurrent pericarditis. Case Vignette A 6-year-old child with a past history of pericarditis almost 2 months ago comes in with a 2-day history of chest pain and fever. Per mother, he stopped his steroids about 2 weeks ago, and for the last 2 days has had a temperature of 102F and has been complaining of sharp mid-sternal chest pain that gets worse when he lies down and is relieved when he sits up and leans forward. On examination, he is tachycardic (heart rate 160 bpm), with normal blood pressure for age. He appears to be in pain (5/10), and on auscultation has a pericardial friction rub. His lab studies are notable for elevated white blood cell count and inflammatory markers (CRP and ESR). His electrocardiogram reveals sinus tachycardia and diffuse ST-elevation in all precordial leads. His echocardiogram demonstrates normal biventricular function and a trace pericardial effusion. His cardiac MRI confirms recurrent pericarditis. He is started on indomethacin and colchicine. He has complete resolution of his symptoms by day 3 of admission and is discharged with close follow-up.

Heart failure is a life-changing diagnosis for a child and their family. Pediatric patients with heart failure experience significant morbidity and frequent hospitalizations, and many require advanced therapies such as mechanical circulatory support and/or heart transplantation. Pediatric palliative care is an integral resource for the care of patients with heart failure along its continuum. This includes support during the grief of a new diagnosis in a child critically ill with decompensated heart failure, discussion of goals of care and the complexities of mechanical circulatory support, the pensive wait for heart transplantation, and symptom management and psychosocial support throughout the journey. In this article, we discuss the scope of pediatric palliative care in the realm of pediatric heart failure, ventricular assist device (VAD) support, and heart transplantation. We review the limited, albeit growing, literature in this field, with an added focus on difficult conversation and decision support surrounding re-transplantation, HF in young adults with congenital heart disease, the possibility of destination therapy VAD, and the grimmest decision of VAD de-activation.