Cost Comparison of In-Suite Versus Portable Tunneled Femoral Central Line Placements in Children Using Time-Driven Activity-Based Costing.

OBJECTIVE: Compare the cost of placing tunneled femoral central lines in the interventional radiology suite to portable bedside placement using time-driven activity-based costing. METHODS: Detailed process maps were created using information generated from interviews with frontline staff, direct shadowing of patient procedures (19 patients-8 in-suite, 11 portable; patient age 4 days to 37 months; 6 males, 13 females), and electronic medical record review (80 patients-44 in-suite, 36 portable; patient age 1 day to 20 months; 42 males, 38 females) who underwent a tunneled femoral central line placement at a tertiary care pediatric hospital from January 1, 2018, to June 30, 2018. Procedures were conducted in-suite using fluoroscopy guidance or portably at the patient's bedside using ultrasound. Capacity cost rates for each resource in the process maps were calculated for personnel, equipment, facilities, and supply costs. Costs for each process step were then calculated by multiplying the capacity cost rate by the mean duration of each step. Stepwise costs were summed for the entire process to generate a cost for each tunneled femoral central line placement pathway. RESULTS: Total pathway time for tunneled femoral central lines placement in-suite was 123 to 134 min (nonsedated) and 120 to 131 min (sedated) for a cost of $923 to $990 and $1,262 to $1,386, respectively. Total pathway time for tunneled femoral central lines placed portably were 117 to 119 min (nonsedated) and 115 to 147 min (sedated) for a cost of $1,060 to $1,066 and $1,379 to $1,393, respectively. CONCLUSION: Total costs of tunneled femoral central lines placed in-suite were similar to total costs for lines placed portably. Cost should not be a primary consideration when deciding upon tunneled femoral central line approach in these patients.

Characterization and effect of metal ions on the formation of the Thermus thermophilus Sco mixed disulfide intermediate.

The Sco protein from Thermus thermophilus has previously been shown to perform a disulfide bond reduction in the CuA protein from T. thermophilus, which is a soluble protein engineered from subunit II of cytochrome ba 3 oxidase that lacks the transmembrane helix. The native cysteines on TtSco and TtCuA were mutated to serine residues to probe the reactivities of the individual cysteines. Conjugation of TNB to the remaining cysteine in TtCuA and subsequent release upon incubation with the complementary TtSco protein demonstrated the formation of the mixed disulfide intermediate. The cysteine of TtSco that attacks the disulfide bond in the target TtCuA protein was determined to be TtSco Cysteine 49. This cysteine is likely more reactive than Cysteine 53 due to a higher degree of solvent exposure. Removal of the metal binding histidine, His 139, does not change MDI formation. However, altering the arginine adjacent to the reactive cysteine in Sco (Arginine 48) does alter the formation of the MDI. Binding of Cu2+ or Cu+ to TtSco prior to reaction with TtCuA was found to preclude formation of the mixed disulfide intermediate. These results shed light on a mechanism of disulfide bond reduction by the TtSco protein and may point to a possible role of metal binding in regulating the activity. IMPORTANCE: The function of Sco is at the center of many studies. The disulfide bond reduction in CuA by Sco is investigated herein and the effect of metal ions on the ability to reduce and form a mixed disulfide intermediate are also probed.