Effect of Poloxamer 188 vs Placebo on Painful Vaso-Occlusive Episodes in Children and Adults With Sickle Cell Disease: A Randomized Clinical Trial.

Importance: Although effective agents are available to prevent painful vaso-occlusive episodes of sickle cell disease (SCD), there are no disease-modifying therapies for ongoing painful vaso-occlusive episodes; treatment remains supportive. A previous phase 3 trial of poloxamer 188 reported shortened duration of painful vaso-occlusive episodes in SCD, particularly in children and participants treated with hydroxyurea. Objective: To reassess the efficacy of poloxamer 188 for vaso-occlusive episodes. Design, Setting, and Participants: Phase 3, randomized, double-blind, placebo-controlled, multicenter, international trial conducted from May 2013 to February 2016 that included 66 hospitals in 12 countries and 60 cities; 388 individuals with SCD (hemoglobin SS, SC, S-ß0 thalassemia, or S-ß+ thalassemia disease) aged 4 to 65 years with acute moderate to severe pain typical of painful vaso-occlusive episodes requiring hospitalization were included. Interventions: A 1-hour 100-mg/kg loading dose of poloxamer 188 intravenously followed by a 12-hour to 48-hour 30-mg/kg/h continuous infusion (n = 194) or placebo (n = 194). Main Outcomes and Measures: Time in hours from randomization to the last dose of parenteral opioids among all participants and among those younger than 16 years as a separate subgroup. Results: Of 437 participants assessed for eligibility, 388 were randomized (mean age, 15.2 years; 176 [45.4%] female), the primary outcome was available for 384 (99.0%), 15-day follow-up contacts were available for 357 (92.0%), and 30-day follow-up contacts were available for 368 (94.8%). There was no significant difference between the groups for the mean time to last dose of parenteral opioids (81.8 h for the poloxamer 188 group vs 77.8 h for the placebo group; difference, 4.0 h [95% CI, -7.8 to 15.7]; geometric mean ratio, 1.2 [95% CI, 1.0-1.5]; P = .09). Based on a significant interaction of age and treatment (P = .01), there was a treatment difference in time from randomization to last administration of parenteral opioids for participants younger than 16 years (88.7 h in the poloxamer 188 group vs 71.9 h in the placebo group; difference, 16.8 h [95% CI, 1.7-32.0]; geometric mean ratio, 1.4 [95% CI, 1.1-1.8]; P = .008). Adverse events that were more common in the poloxamer 188 group than the placebo group included hyperbilirubinemia (12.7% vs 5.2%); those more common in the placebo group included hypoxia (12.0% vs 5.3%). Conclusions and Relevance: Among children and adults with SCD, poloxamer 188 did not significantly shorten time to last dose of parenteral opioids during vaso-occlusive episodes. These findings do not support the use of poloxamer 188 for vaso-occlusive episodes. Trial Registration: ClinicalTrials.gov Identifier: NCT01737814.

Race and Gender Differences in Pediatric Milestone Levels: A Multi-Institutional Study.

The Accreditation Council for Graduate Medical Education milestones assess resident competency in 6 domains. We hypothesized that disparities in milestones exist across race and gender in pediatric residencies. This is a retrospective, cross-sectional, multi-institutional study (3 pediatric residencies, 1446 scores; 316 residents). African American residents received the lowest scores in patient care (PC) (P = .030), medical knowledge (MK) (P = .005), practice-based learning and improvement (PBLI) (P = .003), professionalism (PROF) (P < .001), and interpersonal communication skills (ICS) (P = .005). Differences were most pronounced in PROF (African American mean 3.35 [SD .75], Asian 3.51 (.66), Hispanic 3.58 (.66), white 3.59 (.67)). Female residents received higher scores than male residents in PC (P = .002) and system-based practice (SBP) (P = .049). Female interns received higher MK scores, 2.53 (.44) versus 2.48 (.48), P = .044, but lower scores as third years, 4.00 (.43) versus 4.14 (.45), P = .030. In this study, pediatric milestones differed based on race and gender.

Medulloepithelioma with peculiar clinical presentation, stem cell phenotype and aberrant DNA-methylation profile.

We present a 21-year-old male with a neck mass diagnosed as medulloepithelioma. Despite aggressive chemo- and radio-therapy, the tumor metastasized and proved fatal after seventeen months. The tumor demonstrated robust immunohistochemical expression of multiple markers of embryonic/neural stem cells and embryogenesis from the paraffin embedded tissue. The tumor, expressing LIN28A but negative for the 19q13.42 amplicon, also lacked the characteristic methylation profile for medulloepithelioma and other tumors with similar morphology. The expression of embryonic markers may explain its unresponsiveness to therapy and poor prognosis. Therapies targeted at embryonic cell phenotypes may hold the key for successfully treating cancers with embryonal phenotypes or tumors harboring cells with embryonal phenotypes.

A functional hierarchy for c-Myc target genes? Lessons from MT-MC1.

Deregulation of CMYC is a hallmark of many human cancers. As a general bHLH-ZIP transcription factor, the c-Myc oncoprotein directly regulates the expression of >1500 genes controlled by RNA polymerases I, II and III. This represents a formidable challenge to determining which are the most critical for transformation. Previous work from our laboratory has indicated that MT-MC1, a direct c-Myc target gene, mimics many c-Myc phenotypes. More recently, genome-wide microarray experiments indicate that MT-MC1 itself regulates fewer than 50 downstream target genes, many of which, if not all, are also c-Myc targets. These observations suggest that this small, overlapping subset of target genes plays a particularly important role in c-Myc-mediated transformation. This is supported by the finding that nearly half of MT-MC1-regulated genes have been previously implicated in cancer.

Deregulation of common genes by c-Myc and its direct target, MT-MC1.

In addition to its role in cancer, the c-Myc oncoprotein controls many normal cellular processes as a consequence of its function as a basic helix-loop-helix leucine zipper transcription factor. Determining which of the myriad genes under c-Myc control are relevant for these various roles is thus a major challenge. mt-mc1 is a direct c-Myc target gene whose overexpression recapitulates multiple c-Myc phenotypes, including transformation. Using transcriptional profiling, we now show that MT-MC1-overexpressing myeloid cells misregulate a total of 47 distinct transcripts, a large proportion of which are involved in signal transduction and/or cancer. Analysis of these genes reveals a consensus promoter structure consisting of multiple, often closely spaced c-Myc binding sites and three additional Wilm's tumor and Egr1-like motifs. More than one-third of MT-MC1 target genes are also clustered on six cancer-associated chromosomal loci. Most surprisingly, all of the transcripts examined also are regulated by c-Myc. Finally, an estrogen receptor-MT-MC1 fusion protein was used to establish that all examined transcripts were regulated directly by the chimeric protein. Our results thus indicate that MT-MC1 target genes largely comprise a subset of those regulated by c-Myc. We propose that the properties imparted by MT-MC1 are the result of its control of a small and select c-Myc target gene population.