Targeted profiling of rodent unconjugated bile acids using GC-MS to determine the influence of high-fat diet.

Unconjugated bile acids (BAs) have gained more attention than conjugated BAs in the association studies among diet, gut microbiota, and diseases. GC-MS is probably a good choice for specialized analysis of unconjugated BAs due to its high separation capacity and identification convenience. However, few reports have focused on the rodent unconjugated BAs using GC-MS, and the main library for identification has not included rodent-specific BAs. We developed a GC-MS method for targeted profiling of eight main unconjugated BAs in rodent models, which showed excellent performance on sensitivity, reproducibility, and accuracy. Quantitative reproducibility in terms of relative standard deviation (RSD) was in the range of 2.05-2.91%, with detection limits of 3-55 ng/mL, quantitation limits of 9-182 ng/mL, and the recovery rate of 72-115%. All the calibration curves displayed good linearity with correlation coefficient values (R2 ) more than 0.99. Using the established method, the influence of high-fat diet on the metabolism of unconjugated BAs was revealed. Significant increase in fecal unconjugated BAs induced by high-fat diet would be a potential risk to gut inflammation and cancer. The study provides a convenient and targeted GC-MS method for specialized profiling of rodent unconjugated BAs in physiological and pathological studies.

Evaluation and analysis of incidence and risk factors of lower extremity venous thrombosis after urologic surgeries: A prospective two-center cohort study using LASSO-logistic regression.

BACKGROUND: Deep vein thrombosis (DVT) is among the most frequent complications of surgery. This study aimed to analyse the incidence and risk factors of lower extremity venous thrombosis after urologic surgery. MATERIALS AND METHODS: This prospective two-centre study was conducted from August 2019 to January 2020. Patients who underwent urological procedures were enrolled. The primary endpoint was the detection of asymptomatic or symptomatic DVT of the lower extremity within 7 days after surgery. Univariate and least absolute shrinkage and selection operator (LASSO) logistic regression analyses were performed. RESULTS: Fifty-six of 1011 patients developed DVT. In the univariate analysis, Barthel Index ≤40, d-dimer level ≥0.5 mg/L and age ≥60 years (p < 0.001) were identified as the most significant risk factors. The LASSO logistic regression model identified nine factors: age, history of DVT, lymph node dissection, perioperative steroid use, Caprini score, Barthel Index, D-dimer level, cystectomy, and prostatectomy. CONCLUSION: Our study used the LASSO logistic regression model to provide reliable data on the risk factors for DVT after comprehensive urologic surgery. The incidence of DVT in this group was 5.54%. This might facilitate individualised anticoagulant management in patients undergoing urological procedures.