Patterns of burns and scalds in children

OBJECTIVE

To describe the characteristics of childhood burns and scalds, mechanisms and agents to inform prevention.

METHODS

Prospective multicentred cross-sectional study of children (<16 years) with unintentional burns/scalds from five Emergency Departments (ED), a burns assessment unit and three regional children's Burns Units.

DATA COLLECTED

site, severity, distribution of the burn/scald, age, motor development of the child, agent and mechanism of the injury. Comparative analysis for children <5 and 5-16 years.

RESULTS

Of 1215 children, 58% (709) had scalds, 32% (390) contact burns and 116 burns from other causes, 17.6% (214/1215) were admitted to hospital and the remaining treated in ED or burns assessment centre. 72% (878) were <5 years, peak prevalence in 1-year-olds. Commonest scald agent (<5 years) was a cup/mug of hot beverage 55% (305/554), and commonest mechanism was a pull-down injury 48% (66/554). In 5-16-year-olds, scalds were from hot water 50% (78/155) and spill injuries 76% (118/155). Scalds affected the front of the body in 96% (680/709): predominantly to the face, arms and upper trunk in <5-year-olds, older children had scalds to the lower trunk, legs and hands. Contact burns (<5 years) were from touching 81% (224/277) hot items in the home, predominant agents: hair straighteners or irons 42% (117/277), oven hobs 27% (76/277), 5-16-year-olds sustained more outdoor injuries 46% (52/113). 67% (262/390) of all contact burns affected the hands.

CONCLUSIONS

Scalds to infants and toddlers who pull hot beverages over themselves or sustain burns from touching irons, hair straighteners or oven hobs are a high priority for targeted prevention.

The presence of radiological features on chest radiographs: how well do clinicians agree?

AIM

To compare levels of agreement amongst paediatric clinicians with those amongst consultant paediatric radiologists when interpreting chest radiographs (CXRs).

MATERIALS AND METHODS

Four paediatric radiologists used picture archiving and communication system (PACS) workstations to evaluate the presence of five radiological features of infection, independently in each of 30 CXRs. The radiographs were obtained over 1 year (2008) from children with fever and signs of respiratory distress, aged 6 months to <16 years. The same CXRs were interpreted a second time by the paediatric radiologists and by 21 clinicians with varying experience levels, using the Web 1000 viewing system and a projector. Intra- and interobserver agreement within groups, split by grade and specialty, were analysed using free-marginal multi-rater kappa.

RESULTS

Normal CXRs were identified consistently amongst all 25 participants. The four paediatric radiologists showed high levels of intraobserver agreement between methods (kappa scores between 0.53 and 1.00) and interobserver agreement for each method (kappa scores between 0.67 and 0.96 for PACS assessment). The 21 clinicians showed varying levels of agreement from 0.21 to 0.89.

CONCLUSION

Paediatric radiologists showed high levels of agreement for all features. In general, the clinicians had lower levels of agreement than the radiologists. This study highlights the need for improved training in interpreting CXRs for clinicians and the timely reporting of CXRs by radiologists to allow appropriate patient management.

Extracellular loops and ligand binding to a subfamily of Family A G-protein-coupled receptors

GPCRs (G-protein-coupled receptors) are a large family of structurally related proteins which mediate their effects by coupling to G-proteins. The V(1a)R (V(1a) vasopressin receptor) is a member of a family of related GPCRs that are activated by vasopressin {AVP ([Arg(8)]vasopressin)}, OT (oxytocin) and related peptides. These receptors are members of a subfamily of Family A GPCRs called the neurohypophysial peptide hormone receptor family. GPCRs exhibit a conserved tertiary structure comprising a bundle of seven TM (transmembrane) helices linked by alternating ECLs (extracellular loops) and ICLs (intracellular loops). The cluster of TM helices is functionally important for ligand binding, and, furthermore, activation of GPCRs involves movement of these TM helices. Consequently, it might be assumed that the extracellular face of GPCRs is composed of peptide linkers that merely connect important TM helices. However, using a systematic mutagenesis approach and focusing on the N-terminus and the second ECL of the V(1a)R, we have established that these extracellular domains fulfil a range of important roles with respect to GPCR signalling, including agonist binding, ligand selectivity and receptor activation.

The third extracellular loop of G-protein-coupled receptors: more than just a linker between two important transmembrane helices

GPCRs (G-protein-coupled receptors) are a large family of structurally related proteins, which mediate their effects by coupling with G-proteins. Despite responding to a range of very diverse stimuli, these receptors exhibit a conserved tertiary structure comprising a bundle of seven TM (transmembrane) helices linked by alternating ECLs (extracellular loops) and ICLs (intracellular loops). The hydrophobic environment formed by the cluster of TM helices is functionally important. For example, the 11-cis retinal chromophore of rhodopsin forms a protonated Schiff base linkage to a lysine in TM7, deep within the helical bundle, and small ligands, such as amine neurotransmitters and non-peptide analogues of peptide hormones, also bind within the corresponding region of their cognate receptors. In addition, activation of GPCRs involves relative movement of TM helices to present G-protein interaction sites across the intracellular face of the receptor. Consequently, it might be assumed that the ECLs of the GPCR are inert peptide linkers that merely connect important TM helices. Focusing on ECL3 (third ECL), it is becoming increasingly apparent that this extracellular domain can fulfil a range of important roles with respect to GPCR signalling, including agonist binding, ligand selectivity and receptor activation.