ABSTRACT
A lipase gene (lip3) was cloned from the Pseudomonas aeruginosa strain LST-03 (which tolerates organic solvents) and expressed in Escherichia coli. The cloned sequence includes an ORF consisting of 945 nucleotides, encoding a protein of 315 amino acids (Lip3 lipase, 34.8 kDa). The predicted Lip3 lipase belongs to the class of serine hydrolases; the catalytic triad consists of the residues Ser-137, Asp-258, and His-286. The gene cloned in the present study does not encode the LST-03 lipase, a previously isolated solvent-stable lipase secreted by P. aeruginosa LST-03, because the N-terminal amino acid sequence of the Lip3 lipase differs from that of the LST-03 lipase. Although the effects of pH on the activity and stability of the Lip3 lipase, and the temperature optimum of the enzyme, were similar to those of the LST-03 lipase, the relative activity of the Lip3 lipase at lower temperatures (0-35 degrees C) was higher than that of the LST-03 lipase. In the absence of organic solvents, the half-life of the Lip3 lipase was similar to that of the LST-03 lipase. However, in the presence of most of the organic solvents tested in this study (the exceptions were ethylene glycol and glycerol), the stability of the Lip3 lipase was lower than that of the LST-03 lipase.
Subject(s)
Gene Expression , Lipase/genetics , Lipase/isolation & purification , Pseudomonas aeruginosa/genetics , Amino Acid Sequence , Chromatography, Agarose , DNA Primers , Electrophoresis, Agar Gel , Electrophoresis, Polyacrylamide Gel , Gene Library , Hydrogen-Ion Concentration , Lipolysis/genetics , Molecular Sequence Data , Open Reading Frames/genetics , Plasmids/genetics , Pseudomonas aeruginosa/enzymology , Sequence Alignment , Sequence Analysis, DNA , TemperatureABSTRACT
BACKGROUND: Arthroscopic treatment of tibial plateau fractures were compared with open traditional methods retrospectively. METHODS: Twenty-eight patients were included in this comparative study based on fracture patterns and divided into two groups. Using Schatzker's classification system, patients with type II (split depression), type III (isolated depression) fractures, or other fracture types were included. Nineteen of these patients were treated by arthroscopically assisted management (group S), and the remaining 9 underwent the conventional open method (group O). RESULTS: There was no significant difference between both groups in terms of duration of operation, postoperative flexion, and clinical results. In group S, however, the postoperative rehabilitation was easier and faster (the time to obtain 120 degrees of flexion was 4.6+/-3.9 weeks in group S, 9.1+/-8.6 weeks in group O). Furthermore, 16 of 19 patients (84%) in group S obtained an anatomical reduction (defined as <2 mm of residual displacement after surgery), whereas in group O, only 5 of 9 patients (55%) had an anatomical reduction. Also, accurate diagnosis and treatment of any associated joint pathology was possible with arthroscopic management. CONCLUSION: The arthroscopic procedure is recommended in selected tibial plateau fractures.
