Internalization of near-infrared fluorescent dyes within isolated macrophage populations.

The development and application of microsensor technology has enhanced the ability of scientists to further understand various biological activities, such as changes in the intracellular environment after injury or toxic exposure. NIR microsensor technology may be useful in detecting the cellular injuries or adverse changes during the early onset period, allowing for the administration of therapies to initiate recovery. The development and use of Infrared (IR) and near infrared (NIR) dyes as biological micro-sensors due to their advanced spectral characteristics may be helpful. Three of the more useful NIR dye characteristics include the ability to minimize background interference by extraneous biological matrices, the ability to exhibit optimal molar absorptivity and quantum yields, and the ability to maintain normal cellular activity. Thus, the current study was designed to investigate the ability of selected NIR micro-sensor dyes to undergo cellular internalization, demonstrate intracellular NIR fluorescent signaling, and maintain normal cellular activity. The results demonstrate that the selected NIR micro-sensor dyes undergo cellular internalization. The presence of the dyes within the cells did not affect cell viability. In addition, these dyes demonstrate changes in absorbance and fluorescence after the immune cells were challenged with a stimulant. Moreover, critical cellular functions, such as tumor necrosis factor release and superoxide production were not compromised by the internalization of the fluorescent dyes. These data suggest that selected NIR micro-sensor dyes can undergo intracellular internalization within isolated macrophages without adversely affecting various parameters of normal cellular activity.

Can standard open pediatric urological procedures be performed on an outpatient basis?

PURPOSE: We questioned whether it is feasible in the current era of cost consciousness to perform standard open pediatric urological procedures on an outpatient basis while maintaining patient safety and satisfaction. MATERIALS AND METHODS: We report on 51 consecutive patients 2 months to 13 years old (mean age 4 years 3 months) who underwent a standard open pediatric urological procedure between August 1999 and June 2000. The procedures included ureteral reimplantation in 22 cases (tapered in 2), pyeloplasty in 20, partial nephrectomy in 2, nephrectomy in 2, complete ureterocele reconstruction in 1 and other in 4. The expectation that the procedure would be performed on an outpatient basis was discussed with parents preoperatively. We excluded only cases requiring bowel for reconstruction. A caudal block was administered at the start of the procedure using 0.25% bupivacaine with 1:200,000 epinephrine at a dose of 1 cc/kg. The wound was infiltrated with 1 cc/kg. 0.25% bupivacaine and 0.5 mg./kg. ketorolac was administered at the end of the procedure. As soon as the child awakened, an age appropriate diet was started and 0.5 to 1 mg./kg. codeine with acetaminophen was given every 4 hours. RESULTS: Of the 51 children 44 (86%) were discharged home the day of surgery. Average postoperative hospitalization was 7 hours. One of the 44 children discharged home required a single catheterization elsewhere. There were no other complications or repeat hospitalizations. CONCLUSIONS: Our experience shows that standard open pediatric urological procedures may be performed safely and comfortably on an outpatient basis.