ABSTRACT
We demonstrate an enzyme stabilization approach whereby a model enzyme is PEGylated, followed by controlled chemical modification with glutaraldehyde. Using this stabilization strategy, size increases and aggregation due to intermolecular crosslinking are avoided. Immediately following synthesis, the PEGylated enzyme with and without glutaraldehyde modification possessed specific activities of 372.9 ± 20.68 U/mg and 373.9 ± 15.14 U/mg, respectively (vs. 317.7 ± 19.31 U/mg for the native enzyme). The glutaraldehyde-modified PEGylated enzyme retains 73% original activity after 4 weeks at 37 °C (vs. 2% retention for control).
ABSTRACT
BACKGROUND: This is a retrospective review from March 1994 through October 1996 of 78 patients who underwent laparoscopic Nissen fundoplication for gastroesophageal reflux disease (GERD). The purpose of this study was to evaluate the postoperative results and complications. METHODS: The patient profile included 38 men and 40 women with a mean age of 46 years (range 11 to 81). The main preoperative symptoms included heartburn (92%), respiratory problems (42%), and dysphagia (32%). Preoperative assessment included esophagogastroduodenoscopy, upper gastrointestinal series, esophageal manometry, and 24-hour pH monitoring. Essential indications for surgery included esophagitis (83%), Barrett's esophagus without dysplasia (22%), and esophageal stricture (23%). All patients underwent a 360-degree wrap with a Maloney dilator and division of the short gastric vessels. RESULTS: The mean operative time was 206 minutes (range 90 to 455). The average time for patients to tolerate a full liquid diet was 1.2 days, and the mean hospital stay was 2.4 days. Current follow-up, from 3 to 36 months, showed complete resolution of heartburn without medications in 67 patients (86%), occasional heartburn in 8 patients (10%), and slight improvement of heartburn in 3 patients (4%). Five patients with preoperative Barrett's metaplasia showed no evidence of it postoperatively (n = 2) or marked regression (n = 3). CONCLUSION: Laparoscopic Nissen fundoplication is the procedure of choice for patients with complicated GERD.
