A Prospective Randomized Controlled Trial of the Effect of Maintenance of Continuous Cuff Pressures (20 cmH2O vs 30 cmH2O) on Postoperative Airway Symptoms in Laparoscopic Surgeries.

INTRODUCTION: Recently, laparoscopic surgery has been used in many fields of surgery. It has been reported that cuff pressure becomes high during laparoscopic surgery. Increased cuff pressure may cause postoperative sore throat and hoarseness. Considering previous reports, we hypothesized that maintenance of a fixed low cuff pressure during laparoscopic surgery might be associated with low grades of postoperative sore throat and hoarseness. METHODS: The participants were 100 patients between 20 and 80 years of age who were scheduled to undergo laparoscopic surgery lasting over 2 hours. Patients were randomly allocated to two groups with endotracheal tube cuff pressures fixed at 20 cmH2O (low-pressure group; LPG) and 30 cmH2O (high-pressure group; HPG). We evaluated mainly sore throat and hoarseness on postoperative day 1 using a visual analog scale (VAS; 0-10 cm). Statistical comparisons of values were performed using the unpaired t-test, Mann-Whitney U-test, and chi-square test with values of p < 0.05 considered statistically significant. RESULTS: There were no significant differences in background characteristics between the two groups. Median postoperative scores for the LPG and HPG were 1 (interquartile range, 0-3) and 0 (0-2; p = 0.560) for sore throat and 2 (0-4) and 1 (0-3; p = 0.311) for hoarseness, respectively, and the differences were not significant. CONCLUSION: The effects of maintenance of a fixed low cuff pressure and a fixed high cuff pressure on the degrees of postoperative sore throat and hoarseness after laparoscopic surgery were the same and the grades were low.

Recombinant expression, molecular characterization and crystal structure of antitumor enzyme, L-lysine α-oxidase from Trichoderma viride.

L-Lysine α-oxidase (LysOX) from Trichoderma viride is a homodimeric 112 kDa flavoenzyme that catalyzes the oxidative deamination of L-lysine to form α-keto-ε-aminocaproate. LysOX severely inhibited growth of cancer cells but showed relatively low cytotoxicity for normal cells. We have determined the cDNA nucleotide sequence encoding LysOX from T. viride. The full-length cDNA consists of 2,119 bp and encodes a possible signal peptide (Met1-Arg77) and the mature protein (Ala78-Ile617). The LysOX gene have been cloned and heterologously expressed in Streptomyces lividans TK24 with the enzyme activity up to 9.8 U/ml. The enzymatic properties of the purified recombinant LysOX, such as substrate specificity and thermal stability, are same as those of native LysOX. The crystal structure of LysOX at 1.9 Å resolution revealed that the overall structure is similar to that of snake venom L-amino acid oxidase (LAAO), and the residues involved in the interaction with the amino or carboxy group of the substrate are structurally conserved. However, the entrance and the inner surface structures of the funnel to the active site, as well as the residues involved in the substrate side-chain recognition, are distinct from LAAOs. These structural differences well explain the unique substrate specificity of LysOX.