1.Determination of Aluminum in Natural Waters and Drinking Waters by Alternating Current Oscillopolarography Using Solochrome Violet RS
Ning GAN ; Shuping BI ; Xongbo WEI ; Yongxia TAN
Chinese Journal of Analytical Chemistry 2001;29(2):212-215
A simple and reliable electroanalytical method for the fast determination of aluminum in natural and drinking waters by a. c. oscillopolarography using solochrome violet RS(SVRS) is described. The alkaline buffer solution used was 0.85 mol/L NH3·H2O- NH4 Cl(pH 8.8) containing 5 × 10-5 mol/L SVRS. A sensitive incision due to the redox reaction of Al-SVRS complex adsorption wave on the Hg-film electrode was observed on the dE/dtE oscillogram at - 1.05 V. The incision depth was linearly proportional to the A1 concentration in the range of 1 ×10-7 ~6 × 10-6 mol/L. No serious interference was found. The detection limit of this method was 5 × 10-8 mol/L,and the relative standard deviation was 5.5% for 2 × 10-7 mol/L Al ( n = 10). This method was successfully applied to the determination Al in 22 real samples. The results were found to be in good agreement with those obtained by inductively coupled plasma-atomic emission spectrometry.
2.False-positive HIV-1 nucleic acid testing results in patients with severe thalassemia after receiving cell and gene therapy
Yifan ZHONG ; Jifei NIU ; Yue LI ; Jing LIU ; Xiaohui WANG ; Hao LI ; Yongxia GAN ; Guilian LI ; Chenli ZHENG ; Chenglong LI ; Yifan CAI ; Zijie YANG ; Wei TAN ; Xiaozhen CHEN ; Tiejian FENG ; Cong JIN ; Jin ZHAO
Chinese Journal of Laboratory Medicine 2024;47(4):451-454
A 11-year old female patient with severe thalassemia, receipt a lentivirus-based cell and gene therapy (CGT) therapy in Shenzhen Children′s Hosptial on July 27th, 2021. At the two follow-up visits after discharge, patient were continuously tested positive for HIV screening through HIV Ag/Ab Combo assay (chemiluminescence Immunoassay), and the viral load results of HIV-1 nucleic acid testing (NAT) were both>5 000 copies/ml. The patient can be diagnosed with HIV infection according to the National Guideline for Detection of HIV/AIDS(2020 Revised Edition). The thorough investigation findings and supplementary experiment results indicated that the false-positive HIV-1 NAT results was caused by cross-reactivity between the target sites detected by conventional HIV-1 NAT reagents and the lentiviral vectors fragments integrated into the genome of patient′s hematopoietic stem/progenitor cells. In conclusion, it is important for laboratories to select appropriate HIV-1 NAT testing platforms which won′t cause cross-reactivity for the testing of samples from patients who have been treated with HIV-derived vectors. It is also recommended to design and develop NAT testing platforms with multiple target regions labeled by different fluorescents for HIV NAT supplementation experiment to reduce the risk of false-positive diagnoses of HIV infection.