ABSTRACT
Objective:To study the influencing factors of postoperative complications in patients with malignant biliary obstruction treated by endoscopic radiofrequency ablation(RFA).Methods:Data of patients with malignant biliary obstruction who underwent endoscopic RFA at the Department of Gastroenterology, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine from January 2010 to June 2021 were retrospectively analyzed. There were 62 males and 48 females, with age (74.1±11.1) years. Based on occurrence of postoperative complications, these patients were divided into the complication group ( n=18) and the control group ( n=92). Univariate and multivariate logistic regression analysis were used to analysis the influencing factors of complications. Results:RFA was successfully performed in 110 patients with malignant biliary obstruction, and the technical success rate was 100.0% (110/110). Postoperative complications occurred in 18 patients (16.4%), including 12 patients with of biliary tract infection (8 patients with acute cholangitis, 4 patients with acute cholecystitis) and 6 patients with acute pancreatitis. All these patients responded well to treatment. The proportion of patients who developed complications having associated diabetes, bile duct stenosis length >2.5 cm, fractional RFA for bile duct stenosis, and single stent drainage were significantly higher than those in the control group (all P<0.05). Multivariate logistic regression analysis showed that the risk of complications after endoscopic RFA was significantly increased in patients with diabetes ( OR=6.967, 95% CI: 1.256-38.658) and fractional RFA of bile duct stenosis ( OR=8.297, 95% CI: 1.526-45.122), while the risk of complications after multiple stents drainage ( OR=0.037, 95% CI: 0.008-0.169) was significantly decreased (all P<0.05). Conclusion:Diabetes and fractional RFA of bile duct stenosis were risk factors for complications after endoscopic RFA of malignant biliary obstruction. Multiple stents drainage was a protective factor. Better clinical attention should be paid to the patients with high risk factors.
ABSTRACT
A novel flow-injection chemiluminescence (FI-CL) method free of CL reagent was developed for the determination of captopril based on its enhancing effect on the CL derived from diperiodatoargentate(III)-sulfuric acid system. Compared with the conventional CL system, the CL system based on trivalent silver was characterized of good selectivity for the absence of CL reagent. The CL mechanism was discussed through CL spectra and UV–vis absorption spectra. The conditions of the FI-CL system were investigated and optimized. Under the optimal conditions, the relative CL intensity was linear with the captopril concentration in the range of 0.3–15.0 μg/mL. The detection limit for captopril was 0.05 μg/mL, and the relative standard deviation (n=11) was 2.0% for 5.0 μg/mL captopril. The proposed method was applied to the analysis of captopril in tablet and human urine with the recoveries of 83.1%–112.5%, and the relative standard deviations of 0.5%–4.4%. The results obtained by the proposed method agreed well with those obtained from HPLC method. The proposed method is fast, convenient, and cost-effective for the determination of captopril in medicine and biological samples.
ABSTRACT
A flow-injection chemiluminescence ( FI-CL ) reaction system with diperiodatoargentateⅢ was developed for the determination of hydrocortisone in human serum. The weak chemiluminescence signal from the reaction between DPA and sulfuric acid system can be greatly enhanced in the presence of hydrocortisone. The optimal conditions of the CL system were 1. 0 mol/L H2SO4, 2. 5×10-4 mol/L diperiodatoargentateⅢ, and flow rate of 4. 20 mL/min. Under the optimal conditions, the CL intensity was linearly to the concentration of hydrocortisone from 3 . 0 × 10-10 g/mL to 1 . 0 × 10-7 g/mL and the detection limit was 2 . 2 × 10-10 g/mL ( 3σ) . The relative standard deviation ( RSD ) was 0 . 6% ( n =11 ) for 5 . 0 × 10-8 g/mL hydrocortisone solution. The proposed method was successfully applied to the direct determination of hydrocortisone in serum samples with the recoveries of 93 . 0%-110 . 0%, and the relative standard deviations were 0 . 3%-3 . 2%. The possible chemiluminescence mechanism was investigated by measuring fluorescence spectra and UV-vis absorption spectra of the system.
ABSTRACT
A novel chemiluminescence (CL) reaction was based on the oxidizing reaction of luminol by the trivalent copper-periodate complex (K5[Cu(HIO6)2], DPC) in alkaline medium. The CL intensity could be enhanced in the presence of amikacin sulfate (AKS). A new CL method was developed for the determination of AKS by coupling with flow injection (FI) technology. Because of the distinctive oxidative effect of DPC, the luminol-based CL reaction could occur at a low concentration of 10à7 M. The relative CL intensity was proportional to the concentration of AKS in the range of 4.0 ? 10à9-4.0 ? 10à6 g/mL with the detection limit of 1.2 ? 10à9 g/mL. The relative standard deviation was 2.1% for 8.0 ? 10à9 g/mL AKS (n?9). The proposed method was successfully applied to the direct determination of AKS at the level of ng/mL in serum samples. The recovery varied from 97.0% to 106.3%. A possible mechanism of the CL reaction was discussed in detail by relating to the CL kinetic characteristics and electrochemical activities of the oxidant DPC.
ABSTRACT
Trimethoprim molecularly imprinted polymer (MIP) was prepared as the coating of stir bar sorptive extraction (SBSE) and applied to the trace analysis of trimethoprim and three sulfonamides in complex samples.The MIP-coating was about 21.5 μm thickness with the relative standard deviations (RSD) of 5.9％ (n=10).It was homogeneous and dense with good thermal and chemical stability.The extraction capability of the MIP-coating was 1.7 times over that of the non imprinted polymer (NIP) coating.The MIP coating exhibited selective adsorption ability to sulfonamides,triazines and methotrexate besides antibacterial synergists.The methods for the determination of trimethoprim and three sulfonamides by MIP-coated stir bar sorptive extraction coupled with HPLC were developed.It was successfully applied to the trace trimethoprim analysis in spiked urine and plasma samples.The linear range was 5 to 200 μg/L and the detection limit was 1.6 μg/L.The recoveries in urine and plasma samples were 84.5％ to 91.7％ with RSDs of 2.9％ -4.4％,71.9％ to 85.1％ with RSDs of 3.0％ -7.3％,respectively.The trimethoprim MIP-coated stir bar was also applied to the trace sulfonamides analysis in spiked milk sample.The linear range was 10-200 μg/L,the detection limit was within the range of 4.5-6.1 μg/L,and the recovery was 83.2％ - 110.2％ with RSDs of 4.1％ -8.0％.