Liquid ventilation.

For decades, the fluid-filled lung has been a valuable research model for understanding normal and abnormal pulmonary physiology. It has lagged behind, however, as a useful therapeutic tool. Recently, the potential applications of perflubron's physicochemical and biologic properties have been realized. In animal models of several types of hypoxic respiratory failure, perflubron's efficacy in improving gas exchange and compliance has been demonstrated. Preliminary clinical studies of PLV in neonates who have RDS and CDH, and in children and adults who have ARDS have shown promise. Pivotal prospective, controlled studies have yet to be completed.

Tumor necrosis factor-induced E-selectin expression on vascular endothelial cells.

OBJECTIVE: To determine the tumor necrosis factor (TNF) receptor type involved in induction of E-selectin expression on vascular endothelial cells. DESIGN: Prospective, in vitro repeated-measures analysis of cellular responses. SETTING: Research laboratory in an academic medical center. SUBJECTS: Cultured human umbilical vein endothelial cells. INTERVENTIONS: Human umbilical vein endothelial cells were incubated with recombinant human TNF (rhTNF) to induce the expression of E-selectin on their surfaces. To block rhTNF from binding to receptors, the cells were incubated with monoclonal antibodies against TNF receptors (anti-CD120a and anti-CD120b). TNF-induced E-selectin expression of the endothelial cells, with and without blocking antibodies, was then determined using indirect immunofluorescence and flow cytometry. MEASUREMENTS AND MAIN RESULTS: Blocking of either CD120a or CD120b receptors individually resulted in inhibition of TNF-induced E-selectin expression on human umbilical vein endothelial cells. When both antibodies were added, the inhibition of TNF-induced E-selectin expression was synergistic. Inhibition of E-selectin expression was dependent on both TNF concentrations and antibody concentrations. CONCLUSIONS: Both CD120a and CD120b receptors are involved in TNF-induced E-selectin expression on human umbilical vein endothelial cells. Blocking of both or one receptor type can reduce or totally inhibit expression of E-selectin on human umbilical vein endothelial cells, but the response is dependent on both TNF and antibody concentrations.

The role of MRI in evaluation of an adolescent with a pelvic mass.

Abnormalities of the genital tract are common in adolescent females. Evaluation of pelvic pathology generally involves the use of ultrasonography. Recently, MRI has been shown to be effective in the diagnosis of pelvic pathology in adult females. Here, we present the case of an 11-year-old female with a pelvic mass in whom MRI proved to be an important diagnostic tool.

Control and variability of gastric pH in critically ill children.

OBJECTIVES: To determine the effect of illness severity and acute central nervous system injury on the control and variability of gastric pH in pediatric intensive care unit (ICU) patients receiving ranitidine. DESIGN: Prospective, descriptive study. SETTING: Pediatric ICU of a children's hospital. PATIENTS: Fourteen pediatric ICU patients. INTERVENTIONS: Ranitidine (4 mg/kg/day) was administered to all patients. MEASUREMENTS AND MAIN RESULTS: Patients enrolled in the study were divided into two groups based on illness type and severity. Illness severity was measured by the Pediatric Risk of Mortality (PRISM) score, with a PRISM score of > or = 20 defining severe illness. Illness type was designated as central nervous system or noncentral nervous system. Gastric pH was continuously monitored in all patients using an intragastric, pH-sensitive electrode. Poor control of gastric pH was defined as a pH of < 4.0 for > 20% of the time monitored. The statistical significance of the differences between groups was measured using the Wilcoxon two-sample test or Fisher's exact test. Patients with severe illness or acute central nervous system injury had a lower mean gastric pH than all other patients (4.6 vs. 6.4; p = .008) and spent more time with a gastric pH of < 4.0 than other patients (47.5% of time monitored vs. 12.5% of time monitored; p = .003). Poor control of gastric pH occurred in 100% of patients with severe illness or acute central nervous system injury, while only 20% of the remaining patients had poor control of gastric pH (p = .01). Using power-spectrum analysis to evaluate gastric pH variability, gastric pH in patients receiving bolus ranitidine was more variable than gastric pH in patients receiving ranitidine continuously (p = .045). Illness severity or type had no effect on gastric pH variability (p = .78). CONCLUSIONS: a) Continuous infusion of ranitidine decreases variability of gastric pH in pediatric ICU patients; b) gastric pH variability may make intermittent monitoring of gastric pH inaccurate; c) children with acute central nervous system injury or PRISM scores of > or = 20 have poor control of gastric pH; d) type of injury and PRISM scores predict response to ranitidine therapy.