【Objective】 To analyze the SARS-CoV-2 detection results among blood donors in different periods of COVID-19 pandemic control in Shenzhen and assess the antibody levels and infection status of blood donors in different periods, so as to provide reference for subsequent blood testing strategies. 【Methods】 A total of 4 768 plasma samples of blood donors were subjected to pooled testing by nucleic acid testing(NAT) with 8 samples per pool. Additionally, these samples were subjected to a 1000-fold dilution, and the detection of SARS-CoV-2 total antibody was performed by enzyme-linked immunosorbent assay (ELISA). The 4 768 plasma samples were collected from blood donors at different time points in Shenzhen, with inquiries made to determine whether donors during the COVID-19 pandemic were in the convalescence. The antibody positive rates in blood screening samples during different periods of the pandemic and samples from individuals in the convalescence of COVID-19 infection were analyzed. Furthermore, the antibody levels were examined for differences based on gender, age, and blood type. 【Results】 All 4 768 plasma samples from blood donors were negative by NAT, while 2 342 samples were detected positive by the SARS-CoV-2 total antibody detection, with a positive rate of 49.1%. These samples from four periods (September 30 to October 3, 2022; November 3 to 6, 2022; December 27 to 31, 2022; January 6 to 18, 2023) were subjected to a 1 000-fold dilution for COVID-19 antibody detection, and the positive rates were 21.3%, 15.8%, 65.9%, and 93.9%, respectively. 【Conclusion】 The prevalence of COVID-19 antibodies among blood donors in Shenzhen during different periods of the pandemic varied significantly. There was no difference in antibody prevalence among different genders and blood types, while younger individuals exhibited a higher prevalence of antibodies. The risk of COVID-19 transmission through blood transfusion was found to be extremely low.

[Objective] To conduct a retrospective statistical comparison of alanine aminotransferase (ALT) test values in blood donors prior to blood collection, aiming to analyze the objective characteristics of the population with elevated ALT levels (ALT>50 U/L) and provide reference data for adjusting the screening eligibility threshold for ALT. [Methods] The preliminary ALT screening data of 30 341 blood donor samples collected prior to blood donation from three smart blood donation sites at the Shenzhen Blood Center between 2022 and 2023 were extracted and compared with data from a health examination department of a tertiary hospital in Shenzhen (representing the general population, n=24 906). Both datasets were categorized and statistically described. A retrospective analysis was conducted to examine the associations between ALT test results and factors such as donors' gender, age, ethnicity, donation site, donation season, and frequency of blood donation. [Results] The ALT levels in both blood donors and the general population were non-normally distributed. The 95th percentile of ALT values was calculated as 61.4 U/L (male: 67.8 U/L, female: 39.3 U/L) for blood donors and 58.1 U/L (male: 63.7 U/L, female: 51.2 U/L) for the general population. The non-compliance rates (ALT>50 U/L) were 7.65% (2 321/30 341) in blood donors and 7.08% (1 763/24 906) in the general population. There were significant differences (P<0.05) in the ALT failure rate among blood donors based on gender, age, and donation site, but no significant differences (P>0.05) during the blood donation season. There was no statistically significant difference (P>0.05) in the positive rates of four serological markers (HBsAg, anti HCV, HIV Ag/Ab, anti TP) for blood screening pathogens between ALT unqualified and qualified individuals (2.05% vs 1.5%). If the ALT qualification threshold was raised from 50 U/L to 90 U/L, the non qualification rates of male and female blood donors would decrease from 9.82% (2 074/21 125) to 2.23% (471/21 125) and from 2.70% (249/9 216) to 0.75% (69/9 216), respectively. Among the 154 blood donors who donated blood more than 3 times, 88.31% of the 248 ALT test results were in the range of 50-90 U/L. Among them, 9 cases had ALT>130 U/L, and ALT was converted to qualified in subsequent blood donations. [Conclusion] There are differences in the ALT failure rate among blood donors of different genders and ages, and different blood donation sites and operators can also affect the ALT detection values of blood donors. The vast majority of blood donors with ALT failure are caused by transient and non pathological factors. With the widespread use of blood virus nucleic acid testing, appropriately increasing the ALT qualification threshold for blood donors can expand the qualified population and alleviate the shortage of blood sources, and the risk of blood safety will not increase.

OBJECTIVE: To investigate the effect of β-arrestin1 overexpression on tumor progression in a NCG mouse model bearing T-cell acute lymphocytic leukemia (T-ALL) Molt-4 cell xenograft. METHODS: Molt-4 cells were tagged with firefly-luciferase (F-Luc) by lentiviral infection, and fluorescence intensity of the cells was detected using a luminescence detector. Molt-4 cell lines with β-arrestin1 overexpression or knockdown were constructed by lentivirus infection and injected the tail vein in sub-lethal irradiated NCG mice. Body weight changes and survival time of the xenografted mice were observed, and the progression of T-ALL in the mice was evaluated using an fluorescence imaging system. Sixteen days after xenografting, the mice were euthanatized and tumor cell infiltration was observed in the slices of the liver and spleen. RESULTS: We successfully tagged Molt-4 cells with F-Luc and overexpressed or knocked down β-arrestin1 in the tagged cells. Bioluminescent imaging showed obvious luminescence catalyzed by F-Luc in Molt-4 cells. After injection of Molt-4-Luc cells into irradiated NCG mice, a gradual enhancement of luminescence in the xenografted mice was observed over time, while the body weight of the mice decreased. Compared with the control mice, the mice xenografted with β-arrestin1-overexpressing Molt-4 cells had significantly prolonged survival time ( < 0.001), while the survival time of the mice xenografted with Molt-4 cells with β- arrestin1 knockdown was significantly shortened ( < 0.001). Histological examination revealed fewer infiltrating tumor cells in the liver and spleen of the mice xenografted with β-arrestin1-overexpressing Molt-4 cells in comparison with the mice bearing parental Molt-4 cell xenografts. CONCLUSIONS β-arrestin1 overexpression suppresses tumor progression in mice bearing Molt-4 cell xenograft.
Animals ; Disease Progression ; Heterografts ; Humans ; Mice ; T-Lymphocytes ; Transplantation, Heterologous ; beta-Arrestin 1