Spectrophotometry is a simple hemolytic evaluation method commonly used in new drugs, biomedical materials and blood products. It is for the quantitative analysis of the characteristic absorption peaks of hemoglobin. Therefore, it is essential to select the correct detection wavelength when the evaluation system has influences on the conformation of hemoglobin. Based on the study of changes in the characteristic peaks over time of the hemolysis supernatant in four systems, namely, cell culture medium, phosphate buffered saline (PBS), physiological saline and banked blood preservation solution, using continuous wavelength scanning, the selections of detection wavelength were proposed as follows. In the cell culture medium system, the wavelength of 415 nm should be selected within 4 h; , near 408 nm should be selected within 4~72 h. In PBS system, within 4 h, 541 nm, 577 nm or 415 nm should be selected; 4~72 h, 541 nm, 577 nm or near 406 nm should be selected. In physiological saline system, within 4 h, 414 nm should be selected; 4~72 h, near 405 nm should be selected; within 12 h, 541 nm or 577 nm could also be selected. In banked blood preservation solution system, within 72 h, 415 nm, 540 nm or 576 nm should be selected.
ObjectiveTo establish a more accurately method to detect the residue of 1,4-butanediol diglycidyl-ether (BDDE) in the cross-linked sodium hyaluronic gel so as to provide a scientific testing method for the quality control. MethodsThe gas chromatography was used to explore the thermal stability of BDDE, and the residues of BDDE in sodium hyaluronic gel was detected by fluorescence spectrophotometry. The hyaluronidase was added to the BDDE standard solution and the improved fluorescence spectrophotometer was used to detect the BDDE residues in the cross-linked hyaluronic sodium gel. ResultsA good linearity was obtained as y=14.102x+1.103 (R2=0.999 8) for BDDE. BDDE was unstable under high temperature and long storage time. The relevant fluorescence intensity was detected with hyaluronidase solution. After adding hyaluronidase into the BDDE standard solutions, the advanced linearity was obtained as y=14.027x+7.062 (R2=0.999 9). ConclusionFluorescent spectrophotometry is a simple, rapid, and accurate method to analyze BDDE residue of cross-linked sodium hyaluronic gel. Due to the poor thermal stability, all the factors related to temperature must be excluded during the process, including the temperature control of every step. Furthermore, the adding of hyaluronidase in the pre-preparation of cross-linked sodium hyaluronic gel can bring interference. So when using fluorescent spectrophotometry, adjustment must be taken before the calibration curve is preparation.
ObjectiveTo analyze the cost and performance of five methods for detection of carbapenemase-producing Enterobacteriaceae (CPE), including PCR (method A), Carba NP test (method B), ultraviolet spectrophotometry (method C), modified carbapenem inactivation method (mCIM, method D), and loop-mediated isothermal amplification (LAMP, method E).MethodsPubMed, EMbase, The Cochrane Library, CNKI, WanFang Data and CBM databases were searched using the computer regarding literature on detection of CPE with the same or similar designs, same objectives, and independent results. The search was limited between May 2009 and May 2019. Data on the cost and detection performance of all five methods were extracted, and the four special indexes for laboratory tests, such as sensitivity, specificity, simplicity, and rapidity in the utility were quantified as specific values; subsequently, the cost-effective analysis (CEA), cost-utility analysis (CUA), and multi-attribute utility theory (MAUT) in the detection economic analysis were used to conduct health economics evaluation of five detection methods for CPE.ResultsThe cost of methods A, B, C, D and E were 210.00 yuan, 22.00 yuan, 10.50 yuan, 6.00 yuan, and 60.00 yuan, respectively. The C/E of CEA for the above five methods were 210.00, 22.96, 10.66, 6.14, and 60.00, respectively. The C/U of CUA for the above five methods were 302.16, 32.13, 19.30, 11.13, and 80.00, respectively. The MAUT value of the above five methods were 42.56, 5.00, 2.54, 1.63, and 12.56, respectively.ConclusionIn terms of CEA, CUA, and MAUT, the method D was the highest in economic value, which usually can be used as a routine method for detecting CPE, but it needs a long procedure time; thus, the method E can be used for rapid detection when clinical severe infection occurred, which is superior in both cost-effectiveness and rapidity.