Oral antibiotic bowel preparation reduces length of stay and readmissions after colorectal surgery.

BACKGROUND: Oral antibiotic bowel preparation (OABP) before colorectal resection has been shown to reduce surgical site infections. We examined whether OABP decreases length of stay (LOS) and readmissions for colorectal surgery. STUDY DESIGN: This retrospective study used national Veterans Affairs Surgical Quality Improvement Program preoperative risk and outcomes data linked to Veterans Affairs Administrative and Pharmacy Benefits Management data on patients undergoing elective colorectal resections from 2005 to 2009. Exclusion criteria were preoperative LOS >2 days, American Society of Anesthesiologists class 5, or death before discharge. Patient and surgery characteristics, bowel preparation use, presence of an ostomy, indication for surgery, and indication for readmission using ICD-9 codes were determined. Negative binomial regression was used to model LOS. Logistic regression analyses modeled 30-day readmission. RESULTS: Of the 8,180 patients, 1,161 (14.2%) were readmitted within 30 days. Length of stay and readmissions varied significantly by bowel preparation, procedure, presence of an ostomy, and American Society of Anesthesiologists class. Oral antibiotic bowel preparation was associated with a below-median postoperative LOS (negative binomial regression estimate = -0.1159; p < 0.0001) and fewer 30-day readmissions (adjusted odds ratio = 0.81; 95% CI, 0.68-0.97). Overall, 4.9% were readmitted for infections (ICD-9 codes) and this varied by bowel preparation (no preparation 6.1%, mechanical 5.4%, OABP 3.9%; p = 0.001). The readmission rate for noninfectious reasons was 9.3% and did not differ significantly by bowel preparation (no preparation 9.9%, mechanical 9.6%, OABP 8.8%; p = 0.38). CONCLUSIONS: Oral antibiotic bowel preparation before elective colorectal surgery is associated with shorter postoperative LOS and lower 30-day readmission rates, primarily due to fewer readmissions for infections. Prospective studies are needed to verify these results.

Inhibition of tau polymerization with a cyanine dye in two distinct model systems.

In a host of neurodegenerative diseases Tau, a microtubule-associated protein, aggregates into insoluble lesions within neurons. Previous studies have utilized cyanine dyes as Tau aggregation inhibitors in vitro. Herein we utilize cyanine dye 3,3'-diethyl-9-methyl-thiacarbocyanine iodide (C11) to modulate Tau polymerization in two model systems, an organotypic slice culture model derived from Tau transgenic mice and a split green fluorescent protein complementation assay in Tau-expressing cells. In slice cultures, submicromolar concentrations (0.001 microm) of C11 produced a significant reduction of aggregated Tau and a corresponding increase in unpolymerized Tau. In contrast, treatment with a 1 microm dose promoted aggregation of Tau. These results were recapitulated in the complementation assay where administration of 1 microm C11 produced a significant increase in polymerized Tau relative to control, whereas treatment of cells with 0.01 microm C11 resulted in a marked reduction of aggregated Tau. In the organotypic slice cultures, modulation of Tau aggregation was independent of changes in phosphorylation at disease and microtubule binding relevant epitopes for both dosing regimes. Furthermore, treatment with 0.001 microm C11 resulted in a decrease in both total filament mass and number. There was no evidence of apoptosis or loss of synaptic integrity at either dose, however, whereas submicromolar concentrations of C11 did not interfere with microtubule binding, higher doses resulted in a decrease in the levels of microtubule-bound Tau. Overall, a cyanine dye can dissociate aggregated Tau in an ex vivo model of tauopathy with little toxicity and exploration of the use of these type of dyes as therapeutic agents is warranted.