Background Chylothorax following congenital heart surgery is a common complication with associated morbidities, but consensus treatment guidelines are lacking. Variability exists in the duration of medical treatment and timing for surgical intervention. Methods Following institution of a clinical practice guideline for management of post-operative chylothorax at a single center, pediatric cardiothoracic intensive care unit (ICU) in June 2010, we retrospectively analyzed two cohorts of patients: those with chylothorax from 1/2008-5/2010 (early cohort; n = 118) and from 6/2010-8/2011 (late cohort; n = 45). Data collected included demographics, cardiac surgical procedure, treatments for chylothorax, bloodstream infections, hospital mortality, length of hospitalization, duration of mechanical ventilation, and device utilization. Results There were no demographic differences between the cohorts. No differences were found in octreotide use or surgical treatments for chylothorax. Significant differences were found in median times to chylothorax diagnosis (9 in early cohort versus 6 days in late cohort, p = 0.004), ICU length of stay (18 vs. 9 days, p = 0.01), hospital length of stay (30 vs. 23 days, p = 0.005), and total durations of mechanical ventilation (11 vs. 5 days, p = 0.02), chest tube use (20 vs. 14 days, p = 0.01), central venous line use (27 vs. 15 days, p = 0.001), and NPO status (9.5 vs. 6 days, p = 0.04). Conclusions Institution of a clinical practice guideline for treatment of chylothorax following congenital heart surgery was associated with earlier diagnosis, reduced hospital length of stay, mechanical ventilation, and device utilization for these patients.

The ability to lactate is a process restricted to mammals and is necessary for the survival of nonhuman mammals. Female mice carrying a null mutation in the winged helix transcription factor Foxb1 (previously Mf3/Fkh5/TWH) have lactation defects on inbred genetic backgrounds. To determine the cellular basis of the Foxb1 lactation defect we have inserted a tau-lacZ lineage marker into the locus to follow the fate of Foxb1 expressing cells. This approach has revealed that Foxb1 is expressed in epithelial cells of developing and adult mammary glands as well as previously described regions of the central nervous system. Mammary glands from C57BL/6 Foxb1-/- mice have incomplete lobuloalveolar development. In addition, the tau-lacZ lineage label was used to determine that the mammillothalamic tract was lost in all Foxb1-/- mice. Finally, morphological defects in the inferior colliculi of the midbrain in Foxb1-/- mice correlate with the inability to lactate, suggesting that the midbrain defect, but not the loss of the mammillothalamic tract, may be responsible for the lactation defect.

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Three experiments involved extinction of rats in a straight alley following direct placement in the goal box. Placements were given either before or after running trials in Experiments I and n. In Experiment in only placements with no alley running were given. In each case the presence of a FREE indicated the effectiveness of placements. The data are interpreted in terms of the cue effects of placement.