ABSTRACT
BACKGROUND: Pediatric unintentional falls are the leading cause of injury-related emergency visits for children < 5 years old. The purpose of this study was to identify population characteristics, injury mechanisms, and injury severities and patterns among children < 5 years to better inform age-appropriate falls prevention strategies. METHODS: This retrospective database study used trauma registry data from the lead pediatric trauma system in Georgia. Data were analyzed for all patients < 5 years with an international classification of disease, 9th revision, clinical modification (ICD-9 CM) external cause of injury code (E-code) for unintentional falls between 1/1/2013 and 12/31/2015. Age (months) was compared across categories of demographic variables, injury mechanisms, and emergency department (ED) disposition using Kruskal-Wallis ANOVA and the Mann Whitney U test. The relationships between demographic variables, mechanism of injury (MOI), and Injury Severity Score (ISS) were evaluated using multinomial logistic regression. RESULTS: Inclusion criteria were met by 1086 patients (median age = 28 months; 59.7% male; 53.8% White; 49.1% < 1 m fall height). Younger children, < 1-year-old, primarily fell from caregiver's arms, bed, or furniture, while older children sustained more falls from furniture and playgrounds. Children who fell from playground equipment were older (median = 49 months, p < 0.01) than those who fell from the bed (median = 10 months), stairs (median = 18 months), or furniture (median = 19 months). Children < 1 year had the highest proportion of head injuries including skull fracture (63.1%) and intracranial hemorrhage (65.5%), 2-year-old children had the highest proportion of femur fractures (32.9%), and 4-year-old children had the highest proportion of humerus fractures (41.0%). Medicaid patients were younger (median = 24.5 months, p < 0.01) than private payer (median = 34 months). Black patients were younger (median = 20.5 months, p < 0.001) than White patients (median = 29 months). Results from multinomial logistic regression models suggest that as age increases, odds of a severe ISS (16-25) decreased (OR = 0.95, CI = 0.93-0.97). CONCLUSIONS: Pediatric unintentional falls are a significant burden of injury for children < 5 years. Future work will use these risk and injury profiles to inform current safety recommendations and develop evidence-based interventions for parents/caregivers and pediatric providers.
ABSTRACT
[NiFe]-hydrogenases (Hyd) bind a nickel-iron-based cofactor. The Fe ion of the cofactor is bound by two cyanide ligands and a single carbon monoxide ligand. Minimally six accessory proteins (HypA-HypF) are necessary for NiFe(CN)2CO cofactor biosynthesis in Escherichia coli. It has been shown that the anaerobically purified HypC-HypD-HypE scaffold complex carries the Fe(CN)2CO moiety of this cofactor. In the present study, we have purified the HybG-HypDE complex and used it to successfully reconstitute in vitro active Hyd from E. coli. HybG is a homologue of HypC that is specifically required for the maturation of Hyd-2 and also functions in the maturation of Hyd-1 of E. coli. Maturation of active Hyd-1 and Hyd-2 could be demonstrated in extracts derived from HybG- and HypD-deficient E. coli strains by adding anaerobically purified HybG-HypDE complex. In vitro maturation was dependent on ATP, carbamoylphosphate, nickel and reducing conditions. Hydrogenase maturation was prevented when the purified HybG-HypDE complex used in the maturation assay lacked a bound Fe(CN)2CO moiety. These findings demonstrate that it is possible to isolate incompletely processed intermediates on the maturation pathway and to use these to activate apo-forms of [NiFe]-hydrogenase large subunits.
