Prevention of central venous catheter-related coagulase-negative staphylococcal sepsis in neonates

A randomized, double-blind, controlled trial was conducted to determine whether vancomycin added to parenteral alimentation solution given via a central venous catheter would decrease the incidence of catheter-related coagulase-negative staphylococcal sepsis. Seventy infants with a central venous catheter (CVC) in place were randomly selected to receive total parenteral nutrition--either the standard solution or a solution containing 25 micrograms of vancomycin per milliliter. Catheter-related sepsis was defined as the isolation of the same bacterial species from specimens of both peripheral and CVC blood with the concentration of bacteria at least tenfold greater in the specimen obtained from the CVC. Specimens from the CVCs were cultured on removal of the catheters to determine colonization. The colonization of catheters by coagulase-negative staphylococci was reduced from 40% to 22% (p = 0.03) in the vancomycin group; catheter-related sepsis was reduced from 15% to no cases (p = 0.004). Fewer infants required CVC reinsertion in the vancomycin-treated group (p = 0.02), who also regained birth weight earlier (13.4 vs 17.1 days (p = 0.014)). Adverse effects of vancomycin infusion were not observed. We conclude that vancomycin added to the solution used for total parenteral nutrition effectively reduces catheter-related sepsis in the neonatal intensive care unit and offers other potential benefits such as the need for fewer catheters and earlier weight gain. However, we do not recommend widespread implementation of this technique until there are data regarding the emergence of vancomycin-resistant organisms.

Deficits for representational memory induced by septal and cortical lesions (singly and combined) in rats

A differentiation was made between dispositional memory and representational memory. A delayed-nonmatching-to-sample task in a T-maze operationalized this distinction. Experimental brain lesions in posterior septum and in prelimbic cortex resulted in amnesia for representational memories. The amnesia ameliorated as a function of continued reinforced postoperative testing. When lesions were placed in both structures in the same animals, amnesia for representational memories also occurred, and with further testing, the amnesia ameliorated as indicated by group data. However, examination of the behavioral performance and the lesions in individual animals revealed that when both lesions were adequate, choices remained at chance levels, results suggesting permanent amnesia for representational memories. That the lesion-induced amnesia was restricted to representational memory was indicated by the fact that the rats displayed no amnesia for dispositional memories regarding what to do in the maze. They did not act like naive animals, as they should if they had forgotten the dispositional memories necessary for successful T-maze performance.