The adult retina is organized into three cellular layers--an outer photoreceptor, a middle interneuron and an inner retinal ganglion cell (RGC) layer. Although the retinal pigment epithelium (RPE) and Müller cells are important in the establishment and maintenance of this organization, the signals involved are unknown. Here we show that Sonic hedgehog signaling from RGCs is required for the normal laminar organization in the vertebrate retina.

No abstract

Acute fluid requirements in toxic epidermal necrolysis (TEN) have neither been quantified nor reported. The purpose of this study was to examine acute fluid administration in TEN patients. A consecutive series of criteria and biopsy-confirmed cases of TEN admitted to our burn centre were selected for retrospective analysis. Charts were reviewed for demographic and resuscitation variables for the first (D0), second (D1), and third (D2) 24-hour periods after burn center admission. Twenty-one TEN cases were available for study, with a mean epidermal detachment of 53 +/- 24% TBSA. Mortality was 29%, with all deaths occurring after the study period. Average crystalloid volumes decreased from D0 (2.2 +/- 1.5 ml/kg/%TBSA) through D1 (1.6 +/- 1.1 ml/kg/%TBSA) and D2 (1.4 +/- 1.0 ml/kg/%TBSA), whereas urine output increased from D0 (1.3 +/- 0.9 ml/kg/hr) through D1 (1.4 +/- 0.9 ml/kg/hr) and D2 (1.8 +/- 1.1 ml/kg/hr). Worst base deficit (BD) corrected significantly from D0 to D1 (P = .01) and from D1 to D2 (P = .002). There was no correlation between daily crystalloid volumes and %TBSA detachment. Nonsurvivors had significantly higher severity-of-illness score for TEN and 24-hour mean and worst BDs than survivors, but did not require significantly more crystalloid or display lower urine outputs. Initial provision of approximately 2 ml/kg/%TBSA epidermal detachment to patients with TEN resulted in more than adequate urine output and significant correction of the BD. We emphasize that these data do not represent a resuscitation formula but rather a guideline for initial fluid administration, which should then be titrated to the patient's response.

No abstract