Peri-operative epidural may not be the preferred form of analgesia in select patients undergoing pancreaticoduodenectomy.

BACKGROUND AND OBJECTIVES: Epidural analgesia has become the preferred method of pain management for major abdominal surgery. However, the superior form of analgesia for pancreaticoduodenecomy (PD), with regard to non-analgesic outcomes, has been debated. In this study, we compare outcomes of epidural and intravenous analgesia for PD and identify pre-operative factors leading to early epidural discontinuation. METHODS: A retrospective review was performed on 163 patients undergoing PD between 2007 and 2011. We performed regression analyses to measure the predictive success of two groups of analgesia on morbidity and mortality and to identify predictors of epidural failure. RESULTS: Intravenous analgesia alone was given to 14 (9%) patients and 149 patients (91%) received epidural analgesia alone or in conjunction with intravenous analgesia. Morbidity and mortality were not significantly different between the two groups. Early epidural discontinuation was necessary in 22 patients (15%). Those older than 72 and with a BMI < 20 (n = 5) had their epidural discontinued in 80% of cases compared to 12% not meeting these criteria. However, early epidural discontinuation was not associated with increased morbidity and mortality. CONCLUSION: Epidural analgesia may be contraindicated in elderly, underweight patients undergoing PD given their increased risk of epidural-induced hypotension or malfunction.

Capillary electrophoretic development of aptamers for a glycosylated VEGF peptide fragment.

The emergence of functional genomics and proteomics has added to the growing need for improved analysis methods that can detect and distinguish between protein variants resulting from allelic variation, mutation, or post-translational modification. Aptamers, single-stranded DNA or RNA molecules that fold into three-dimensional structures conducive to binding targets, have become an attractive alternative to antibodies for this type of analysis. Although aptamers have been developed for a wide range of target species, very few sequences have been identified that bind selectively to proteins with specific post-translational modifications. Using capillary electrophoresis-based selection, we have developed DNA aptamer sequences that selectively bind an N-glycosylated peptide fragment of vascular endothelial growth factor (VEGF). The selection method incorporates alternating positive- and counter-selection steps in free solution in order to obtain aptamers with both high affinity toward the glycosylated target and high selectivity versus a non-glycosylated variant. Affinity capillary electrophoresis and surface plasmon resonance binding assays indicate these sequences have low-µM dissociation constants and preferentially bind the glycosylated peptide with as much as 50-fold specificity. Such aptamers could serve as tools for rapid and simple monitoring of disease-linked functional changes in proteins, with potential applications in drug screening and disease diagnosis.