Congenital Anomalies of the Kidneys and Urinary Tract.

Congenital anomalies of the kidneys and urinary tract encompass the spectrum of disorders that include the kidneys, ureters, bladder, and urethra. These abnormalities often lead to altered renal size and location, dysplastic changes in the kidney parenchyma, and anomalies in the collecting system. Though the etiology of each of these conditions can be variable, it is known that the collection of these defects represent 40% to 50% of all pediatric end-stage renal disease worldwide. The multifaceted management of these conditions is aimed at preserving kidney function and ultimately delaying the need for transplantation. With the advancement of prenatal ultrasonographic techniques, these conditions are more likely to be diagnosed before birth, which often leads to rapid postnatal intervention and better outcomes.

Rest-Based Concussion Management of Pediatric Emergency Medicine Providers.

OBJECTIVES: This study aimed to survey pediatric emergency medicine (PEM) providers on their management of 2 hypothetical acute concussion scenarios. We hypothesized that most providers would recommend a management strategy based on cognitive and physical rest. METHODS: Fifty-nine percent (46/78) of PEM providers that were surveyed completed the study. The survey consisted of 2 clinical scenarios-a female patient with a mild concussion and a male patient with a moderate concussion. Practitioners were asked questions regarding how they would hypothetically manage these patients in terms of recommendations for returning to school and returning to sports. RESULTS: Eighty-six percent of providers recommended moderate time off from school for the moderate concussion scenario compared with 67% of providers in the mild concussion scenario (P = 0.008). In regard to return to sports, all providers recommended moderate time off in both scenarios, including 78% of providers who recommended clearance by a physician in the moderate concussion scenario. CONCLUSIONS: In both of our hypothetical concussion scenarios, including a very mild head injury, most PEM providers surveyed recommended a management strategy that included a moderate degree of a delay of return to school and sports. Given recent evidence suggesting that prolonged rest does not reduce the risk of prolonged concussion symptoms, recommendations of periods of cognitive rest, particularly absences from school, should be approached cautiously. Future studies should examine why providers are recommending rest-based treatment strategies and the potential benefits of active rehabilitation.

Agenesis of the Corpus Callosum Due to Defective Glial Wedge Formation in Lhx2 Mutant Mice.

Establishment of the corpus callosum involves coordination between callosal projection neurons and multiple midline structures, including the glial wedge (GW) rostrally and hippocampal commissure caudally. GW defects have been associated with agenesis of the corpus callosum (ACC). Here we show that conditional Lhx2 inactivation in cortical radial glia using Emx1-Cre or Nestin-Cre drivers results in ACC. The ACC phenotype was characterized by aberrant ventrally projecting callosal axons rather than Probst bundles, and was 100% penetrant on 2 different mouse strain backgrounds. Lhx2 inactivation in postmitotic cortical neurons using Nex-Cre mice did not result in ACC, suggesting that the mutant phenotype was not autonomous to the callosal projection neurons. Instead, ACC was associated with an absent hippocampal commissure and a markedly reduced to absent GW. Expression studies demonstrated strong Lhx2 expression in the normal GW and in its radial glial progenitors, with absence of Lhx2 resulting in normal Emx1 and Sox2 expression, but premature exit from the cell cycle based on EdU-Ki67 double labeling. These studies define essential roles for Lhx2 in GW, hippocampal commissure, and corpus callosum formation, and suggest that defects in radial GW progenitors can give rise to ACC.

Mechanism of reduced lung injury by high-frequency nasal ventilation in a preterm lamb model of neonatal chronic lung disease.

The mechanism underlying the potentially beneficial effects of the "gentler" modes of ventilation on chronic lung disease (CLD) of the premature infant is not known. We have previously demonstrated that alveolar parathyroid hormone-related protein-peroxisome proliferator-activated receptorγ (PTHrP-PPARγ) signaling is critically important in alveolar formation, and this signaling pathway is disrupted in hyperoxia- and/or volutrauma-induced neonatal rat lung injury. Whether the same paradigm is also applicable to CLD, resulting from prolonged intermittent mandatory ventilation (IMV), and whether differential effects of the mode of ventilation on the PTHrP-PPARγ signaling pathway explain the potential benefits of the "gentler" modes of ventilation are not known. Using a well-established preterm lamb model of neonatal CLD, we tested the hypothesis that ventilatory support using high-frequency nasal ventilation (HFNV) promotes alveolar PTHrP-PPARγ signaling, whereas IMV inhibits it. Preterm lambs managed by HFNV or IMV for 21 d following preterm delivery at 132-d gestation were studied by Western hybridization and immunofluorescence labeling for key markers of alveolar homeostasis and injury/repair. In lambs managed by IMV, the abundance of key homeostatic alveolar epithelial-mesenchymal markers was reduced, whereas it was significantly increased in the HFNV group, providing a potential molecular mechanism by which "gentler" modes of ventilation reduce neonatal CLD.