Characteristics of Pediatric Patients With Retained Bullet Fragments and Need for Follow-Up Blood Lead Monitoring.

OBJECTIVES: Multiple case reports of lead toxicity related to retained bullet fragments in pediatric patients sustaining gunshot wound have been published. The purpose of the present study was to determine whether the demographic and clinical characteristics of gunshot wounds (GSWs) could be classified high/low risk and whether routine blood lead monitoring is necessary in these patients. METHODS: A single-center prospective case series of pediatric GSW patients presenting to the emergency department (ED). The data points that were collected and analyzed included age, sex, race, wound location, disposition, and baseline and follow-up lead levels within 6 months post-injury. RESULTS: Twenty patients were enrolled in the study and the median age was 7.5 years (interquartile range 5.25-10.75); 75% of the patients were African American. A total of 15 patients (75%) had injuries in either a lower or upper extremity, 9 of whom required admission. Almost all of the injuries involving the head, chest, or abdomen required admission. Of the patients, 65% were admitted and 35% were discharged. All of the patients had an initial blood lead level taken, and follow-up lead levels were determined at 6 months post-injury to be <5 µg/dL. Twelve of 20 patients were lost to follow-up. CONCLUSIONS: Pediatric GSW is common in male African Americans and these patients had baseline and follow-up lead levels below the reference level. These patients were difficult to follow up. Based on the available data, follow-up lead monitoring may not be indicated.

Adenosine receptor-mediated adhesion of endothelial progenitors to cardiac microvascular endothelial cells.

Intracoronary delivery of endothelial progenitor cells (EPCs) is an emerging concept for the treatment of cardiovascular disease. Enhancement of EPC adhesion to vascular endothelium could improve cell retention within targeted organs. Because extracellular adenosine is elevated at sites of ischemia and stimulates neovascularization, we examined the potential role of adenosine in augmenting EPC retention to cardiac microvascular endothelium. Stimulation of adenosine receptors in murine embryonic EPCs (eEPCs) and cardiac endothelial cells (cECs) rapidly, within minutes, increased eEPC adhesion to cECs under static and flow conditions. Similarly, adhesion of human adult culture-expanded EPCs to human cECs was increased by stimulation of adenosine receptors. Furthermore, adenosine increased eEPC retention in isolated mouse hearts perfused with eEPCs. We determined that eEPCs and cECs preferentially express functional A1 and A2B adenosine receptor subtypes, respectively, and that both subtypes are involved in the regulation of eEPC adhesion to cECs. We documented that the interaction between P-selectin and its ligand (P-selectin glycoprotein ligand-1) plays a role in adenosine-dependent eEPC adhesion to cECs and that stimulation of adenosine receptors in cECs induces rapid cell surface expression of P-selectin. Our results suggest a role for adenosine in vasculogenesis and its potential use to stimulate engraftment in cell-based therapies.