Dietary fat overcomes the protective activity of thrombospondin-1 signaling in the Apc(Min/+) model of colon cancer.

Thrombospondin 1 is a glycoprotein that regulates cellular phenotype through interactions with its cellular receptors and extracellular matrix-binding partners. Thrombospondin 1 locally regulates angiogenesis and inflammatory responses that contribute to colorectal carcinogenesis in Apc(Min/+) mice. The ability of thrombospondin 1 to regulate responses of cells and tissues to a variety of stresses suggested that loss of thrombospondin 1 may also have broader systemic effects on metabolism to modulate carcinogenesis. Apc(Min/+):Thbs1(-/-) mice exhibited decreased survival and higher tumor multiplicities in the small and large intestine relative to Apc(Min/+) mice when fed a low (5%) fat western diet. However, the protective effect of endogenous thrombospondin 1 was lost when the mice were fed a western diet containing 21% fat. Biochemical profiles of liver tissue identified systemic metabolic changes accompanying the effects of thrombospondin 1 and dietary lipid intake on tumorigenesis. A high-fat western diet differentially regulated elements of amino acid, energy and lipid metabolism in Apc(Min/+):Thbs1(-/-) mice relative to Apc(Min/+):Thbs1(+/+)mice. Metabolic changes in ketone body and tricarboxylic acid cycle intermediates indicate functional interactions between Apc and thrombospondin 1 signaling that control mitochondrial function. The cumulative diet-dependent differential changes observed in Apc(Min/+):Thbs1(-/-) versus Apc(Min/+) mice include altered amino acid and lipid metabolism, mitochondrial dysfunction, eicosanoids and ketone body formation. This metabolic profile suggests that the protective role of thrombospondin 1 to decrease adenoma formation in Apc(Min/+) mice results in part from improved mitochondrial function.

A prospective study of two intravenous catheter securement techniques in a skilled nursing facility.

A prospective, controlled study was undertaken in a skilled nursing facility to determine whether a sterile catheter securement device (StatLock i.v., Venetec International, Mission Viejo, CA) would provide better intravenous therapy outcomes than a standard securement technique. The StatLock-device resulted in significantly longer average catheter dwell times (3.95 days versus 2.45 days) and significantly fewer total complications (65 versus 155). In addition, the securement device reduced the total time spent managing a vascular access device by 13.5 minutes per patient. Thus, the StatLock i.v. device improved overall clinical outcomes of i.v. therapy and the quality of care.

Stability of azacitidine in infusion fluids.

The stability of azacitidine in four infusion fluids was studied. Azacitidine was reconstituted and diluted to final concentrations of 0.2 mg/ml and 2.0 mg/ml in glass bottles and plastic i.v. bags containing 0.9% sodium chloride injection, 5% dextrose injection, lactated Ringer's injection, or Normosol -R. All admixtures containing azacitidine 2.0 mg/ml and both drug concentrations in Normosol -R were prepared in glass bottles only. The pH of each solution was measured before mixing, immediately after mixing, and after six hours. Duplicate samples of each solution were removed for assay by high-performance liquid chromatography at zero time, then at hourly intervals for six hours, and again at 25 hours. Three experimental runs were performed for each combination of drug concentration, infusion fluid, and type of container. The percentage of initial (zero time) concentration remaining was determined and plotted versus time. This plot was used to calculate the t90 (time at which 90% of the initial concentration remained) for each solution. The t90 values did not exceed three hours for any of the solutions studied. At the 0.2 mg/ml concentration, the t90 value in 5% dextrose injection (0.8 hours) was much smaller than that of the other solutions, which had t90 values of about two hours. In plastic bags, the percentage of initial azacitidine concentration remaining after six hours was less in 5% dextrose injection than in any other solution. The t90 values for all solutions containing azacitidine 2.0 mg/ml were similar, ranging from 2.4 to 3.0 hours.(ABSTRACT TRUNCATED AT 250 WORDS)