Background-Existing guidelines for optimal positioning of endotracheal tubes in neonates are based on scanty data and relate to measurements that are either non-linear or poorly reproducible in sick infants. Foot length can be measured simply and rapidly and is related to a number of external body measurements. Objectives-To evaluate the relation of foot length to nasotracheal length in direct measurements at post mortem examinations, and then compare its clinical relevance with traditional weight based estimates in a randomised controlled trial. Methods-The dimensions of the upper airway were measured at autopsy in 39 infants with median (range) postmenstrual age and birth weight of 32 (24-43) weeks and 1630 (640-3530) g. The regression equations with 95% prediction intervals were calculated to estimate the optimal nasotracheal length from foot length. In a randomised trial, 59 neonates were nasally intubated according to foot length and body weight based estimates to assess the achievement of "optimal" and "satisfactory" tube placements. Results-In the direct measurements of the airway at autopsy, foot length was a better predictor of nasotracheal distances (r 2 = 0.79) than body weight, gestational age, and head circumference (r 2 = 0.67, 0.58, and 0.60 respectively). Measurement of foot length was easy and highly reproducible. In the randomised controlled trial, there were no significant diVerences between the foot length and body weight based estimates in the rates of optimal (44% v 56%) and satisfactory (83% v 72%) endotracheal tube placements. Conclusions-Foot length is a reliable and reproducible predictor of nasotracheal tube length and is at least as accurate as the conventional weight based estimation. This method may be particularly valuable in sick unstable infants. (Arch Dis Child Fetal Neonatal Ed 2001;85:F60-F64)

The liver X receptors α and β are orphan nuclear receptors that are key regulators in maintaining cholesterol homeostasis. Originally they were found to play an important role in reverse cholesterol transport, a pathway for the removal of excess cellular cholesterol. However several groups have now shown that the liver X receptors also functions in lipid and carbohydrate metabolism, cellular differentiation, apoptosis and many immune responses. Tissue distribution of the two paralogues differs with liver X receptor β ubiquitously expressed, while liver X receptor α is confined to the liver, kidney, intestine, spleen, adipose tissue, macrophages and skeletal muscle. The endogenous ligands for the liver X receptors are certain oxidized derivatives of cholesterol, the oxysterols. Upon activation by oxysterols, the receptors form obligate heterodimers with retinoid X receptors α, β and γ; and become competent to activate the transcription of target genes.

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Many clinicians intubate newborns using a stylet, but how many always check if the device is intact after use? We describe a case of endobronchial obstruction by a plastic sheath coating the metal stylet, and suggest ways to reduce the incidence of this serious iatrogenic complication.