Periaortic Abdominal Fat Area as a Predictor of Surgical Difficulties during Extraperitoneal Laparoscopic Para-aortic Lymphadenectomy.

STUDY OBJECTIVE: To evaluate whether obesity is a marker of surgical difficulty during extraperitoneal para-aortic lymphadenectomy. DESIGN: Retrospective observational cohort study. SETTING: Tertiary medical center in the Kanazawa area of Japan. PATIENTS: Eighty-four patients with primary endometrial cancer who underwent extraperitoneal laparoscopic para-aortic lymphadenectomy (LPAND) between January 2005 and December 2017 were included. INTERVENTIONS: We investigated the correlation between operative times and body mass indexes, visceral fat areas, and periabdominal artery fat areas (PAFAs). The number of lymph nodes harvested was used as an indicator of the degree of surgical completion. MEASUREMENTS AND MAIN RESULTS: There was no correlation between the operative time and body mass index. Significant correlations were observed between operative time and visceral fat area (p = .026; r = 0.243) and between operative time and PAFA (p = .007; r = 0.293). A multivariate analysis showed that PAFA was a significant independent marker that could be used to predict prolonged operative times for extraperitoneal LPAND (p = .045; odds ratio, 3.05). The number of para-aortic lymph nodes harvested was not significant in the high- and low-PAFA groups (22 and 25, respectively; p = .525). CONCLUSION: PAFA is an adequate marker of prolonged operative time for extraperitoneal LPAND among patients with endometrial cancer.

Electrochemical consideration on the optimum pH of bilirubin oxidase.

Steady-state current-potential curves were obtained for the direct electron transfer (DET) of bilirubin oxidase (BOD) at a highly oriented pyrolytic graphite electrode, and the theoretical analysis based on nonlinear regression enabled us to determine the formal redox potential (E degrees') of BOD in a wide pH range of 2.0 to 8.5. Cyclic voltammetric measurements were also performed for substrates, including p-phenylenediamine (PPD), o-aminophenol (OAP), and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and their E degrees ' values or the anodic peak potentials (for OAP) were determined at various pH values. The difference in the redox potentials between BOD and substrates (DeltaE degrees') showed a maximum at pH 6.5 to 8.0, pH 6.5 to 8.0, and pH 3.5 to 4.5 for PPD, OAP, and ABTS, respectively. These pH ranges should be thermodynamically most favorable for the electron transfer between BOD and the respective substrates. In practice, the pH ranges showing a maximum DeltaE degrees' corresponded well with the optimum pH values for the O(2) reduction activity of BOD: pH 6.5 to 7.5, pH 8.0 to 8.5, and pH 4.0 for PPD, OAP, and ABTS, respectively. Thus, it was suggested that DeltaE degrees ' should be one of the primary factors determining the activity of BOD with the substrates.

Preparation of functional single-chain antibodies against bioactive gibberellins by utilizing randomly mutagenized phage-display libraries.

Screening randomly mutagenized proteins displayed on a phage surface by biopanning is a powerful strategy to obtain evolved clones with improved properties such as higher stability and functionality. We utilized this method to overcome the problem that functional single-chain antibodies against active gibberellins, a class of plant hormones, can not be prepared by some of the conventional methods. Single-chain antibody libraries with random mutations were constructed from two independent anti-bioactive gibberellin monoclonal antibody lines in a phagemid vector, so that the mutagenized scFvs were expressed in a phage-displayed form upon helper phage infection. From both libraries, scFv clones with binding activity to GA(4) were successfully obtained by successive rounds of biopanning against BSA-GA(4), the original immunogen. The results are highly suggestive that this approach might be a general solution when a single-chain antibody does not show binding activity. We found further that a ribosomal frameshift to complement a nonsense mutation frequently occurred in an amber suppressor strain of E. coli TG1, resulting in the display of a functional antibody, while such a nonsense mutant failed to produce a soluble antibody in a non-amber suppressor strain. This result explains at least partly why single-chain antibodies are sometimes functional only in a phage-displayed form, not in a soluble form.