Background-More than 50% of >270 000 childhood cancer survivors in the United States have been treated with anthracyclines and are therefore at risk of developing cardiotoxicity. Cardiac magnetic resonance (CMR) has demonstrated utility to detect diffuse interstitial fibrosis and changes in regional myocardial function. We hypothesized that CMR would identify occult cardiotoxicity characterized by structural and functional myocardial abnormalities in a cohort of asymptomatic pediatric cancer survivors with normal global systolic function. Methods and Results-Forty-six long-term childhood cancer survivors with a cumulative anthracycline dose ≥200 mg/m 2 and normal systolic function were studied 2.5 to 26.9 years after anthracycline exposure. Subjects underwent transthoracic echocardiography, CMR with routine cine acquisition, tissue characterization, and left ventricular strain analysis using a modified 16-segment model. Extracellular volume was measured in 27 subjects, all of whom were late gadolinium enhancement negative. End-systolic fiber stress was elevated in 45 of 46 subjects. Low average circumferential strain magnitude (ε cc ) −14.9±1.4; P<0.001, longitudinal strain magnitude (ε ll ) −13.5±1.9; P<0.001, and regional peak circumferential strain were seen in multiple myocardial segments, despite normal global systolic function by transthoracic echocardiography and CMR. The mean T1 values of the myocardium were significantly lower than that of control subjects at 20 minutes (458±69 versus 487±44 milliseconds; P=0.01). Higher mean extracellular volume was observed in female subjects (0.34 versus 0.22; P=0.01). The purpose of this study was to use CMR T1 mapping techniques and measures of myocardial strain by tagged cine MRI to detect interstitial disease and changes in regional myocardial function in childhood cancer survivors. We tested the hypothesis that individuals with a history of high-dose anthracycline therapy may have occult cardiotoxicity, manifested by a decrease in circumferential ε cc and longitudinal ε ll strain magnitude and changes in myocardial T1 and ECV, despite normal standard measures of global left ventricular (LV) systolic function. Conclusions-Asymptomatic Methods Study PopulationEligible subjects with a cumulative anthracycline dose ≥200 mg/m 2 and normal LV systolic function defined as TTE-based shortening fraction ≥29% were identified and prospectively enrolled through a registry of pediatric cancer survivors treated with anthracyclines between 1985 and January 2011. Inclusion criteria for this study are shown in Figure 1. Subjects with high-dose radiation exposure to the chest (>3000 cGy) were excluded from the study to minimize the known synergistic effect of therapeutic radiation on cardiotoxicity. 5,21This study was approved by the Institutional Review Board at the Connecticut Children's Medical Center. The medical records of all enrolled subjects were reviewed to identify known risk factors associated with cardiotoxicity. Conversions to isotoxic equivalents of anthracycline a...

SMART syndrome (stroke-like migraine attacks after radiation therapy) is a rare condition that involves complex migraines with focal neurologic findings in patients following cranial irradiation for central nervous system malignancies. Little is known about the mechanisms behind the disorder, making successful treatment challenging. We report 2 new cases of SMART syndrome in pediatric patients as well as review all documented cases of the syndrome. Each of our 2 pediatric patients suffered multiple episodes. Attacks were characterized by severe headache, visual disturbance, aphasia, and weakness. Recovery occurred over several days to weeks. The data from all documented reports of SMART syndrome indicate a greater prevalence for male gender. An age-dependent pattern of onset was also observed, with a greater variability of syndrome onset in patients who received cranial irradiation at a younger age. SMART appears to be a reversible, recurrent long-term complication of radiation therapy with possible age- and gender-related influences.

Host defenses in the human neonate are limited by immaturity in phagocytic immunity. Such limitations seem to predispose infected newborns to neutropenia from an exhaustion of the neutrophil reserve. Among the critical defects thus far identified in neonatal phagocytic immunity is a specific reduction in the capacity of mononuclear cells to express granulocyte colony-stimulating factor (G-CSF) after stimulation. However, the safety, pharmacokinetics, and biological efficacy of administration of recombinant human (rh)G-CSF to infected human newborns to compensate for this deficiency is unknown. Forty-two newborn infants (26 to 40 weeks of age) with presumed bacterial sepsis within the first 3 days of life were randomized to receive either placebo or varying doses of rhG-CSF (1.0, 5.0 or 10.0 micrograms/kg every 24 hours [36 patients] or 5.0 or 10.0 micrograms/kg every 12 hours [6 patients]) on days 1, 2, and 3. Complete blood counts with differential and platelet counts were obtained at hours 0, 2, 6, 24, 48, 72, and 96. Circulating G-CSF concentrations were determined at hours 0, 2, 6, 12, 14, 16, 18, 24, and 36. Tibial bone marrow aspirates were obtained after 72 hours for quantification of the bone marrow neutrophil storage pool (NSP), neutrophil proliferative pool, granulocyte progenitors, and pluripotent progenitors. Functional activation of neutrophils (C3bi expression) was determined 24 hours after rhG-CSF or placebo administration. Intravenous rhG-CSF was not associated with any recognized acute toxicity. RhG-CSF induced a significant increase in the blood neutrophil concentration 24 hours after the 5 and 10 micrograms/kg doses every 12 and 24 hours and it was sustained as long as 96 hours. A dose-dependent increase in the NSP was seen following rhG-CSF. Neutrophil C3bi expression was significantly increased at 24 hours after 10 micrograms/kg every 24-hour dose of rhG- CSF. The half-life of rhG-CSF was 4.4 +/- 0.4 hours. The rhG-CSF was well tolerated at all gestational ages treated. The rhG-CSF induced a significant increase in the peripheral blood and bone marrow absolute neutrophil concentration and in C3bi expression. Future clinical trials aimed at improving the outcome of overwhelming bacterial sepsis and neutropenia in newborn infants might include the use of rhG-CSF.

This study demonstrated for the first time that changes in miR expression occurs in pediatric AC patients. These findings suggest that miRs are a potential strategy for early identification of AC patients susceptible to LV dysfunction.