The Role of Surveillance Inspections in Reducing False-Positives of SARS-CoV-2 Omicron Variants during the COVID-19 Epidemic.

Objective: This study aims to assess the effectiveness of surveillance inspections conducted by the provincial health committee in Quanzhou city during a COVID-19 outbreak in reducing false-positive results in SARS-CoV-2 RT-PCR assays. Method: The team conducted on-site inspections of laboratories that participated in mass screening, recording any violations of rules. Results: The positive cases in five rounds of mass screening were 23, 173, and 4 in Licheng District, Fengze District, and Luojang District, respectively. The false-positive rates in the five rounds of mass screening were 0.0099%, 0.0063%, 0.0018%, 0.0006%, and 0%, respectively. The study also recorded that the number of violations in the seven selected laboratories was 36, 68, 69, 42, 60, 54 and 47. The corresponding false-positive rates were 0.0012%, 0.0060%, 0.0082%, 0.0032%, 0.0060%, 0.0027%, and 0.0021%, respectively. The study found a positive correlation between false-positive rates and the number of violations (r = 0.905, P=0.005), and an inverse correlation between false-positive rates and the frequency of surveillance inspections (r = -0.950, P < 0.001). Conclusion: Daily surveillance inspection in laboratories can remind laboratories to strictly comply with standard procedures, focus on laboratory quality control, and reduce the occurrence of false-positive cases in SARS-CoV-2 nucleic acid tests to some extent. This study recommends that government decision-making departments establish policies and arrange experts to conduct daily surveillance inspections to improve laboratory quality control.

[Research on monitoring land subsidence in Beijing plain area using PS-InSAR technology].

In the present paper, the authors use permanent scatterers synthetic aperture radar interferometry (PS-InSAR) technique and 29 acquisitions by Envisat during 2003 to 2009 to monitor and analyze the spatial-temporal distribution and mechanism characterize of land subsidence in Beijing plain area. The results show that subsidence bowls have been bounded together in Beijing plain area, which covers Chaoyang, Changping, Shunyi and Tongzhou area, and the range of subsidence has an eastward trend. The most serious regional subsidence is mainly distributed by the quaternary depression in Beijing plain area. PS-Insar results also show a new subsidence bowl in Pinggu. What's more, the spatial and temporal distribution of deformation is controlled mainly by faults, such as Liangxiang-Shunyi fault, Huangzhuang-Gaoliying fault, and Nankou-Sunhe fault. The subsidence and level of groundwater in study area shows a good correlation, and the subsidence shows seasonal ups trend during November to March and seasonal downs trend during March to June along with changes in groundwater levels. The contribution of land subsidence is also influenced by stress-strain behavior of aquitards. The compaction of aquitards shows an elastic, plastic, viscoelastic pattern.

Fuzheng Qingjie granules potentiate the anticancer effect of cyclophosphamide by regulating cellular immune function and inducing apoptosis in Hepatoma 22 tumor-bearing mice.

Fuzheng Qingjie (FZQJ) is a polyherbal Chinese medicine that has previously been implemented as an adjuvant therapy for gastrointestinal cancer. The present study investigated whether FZQJ is able to potentiate the anticancer effect of cyclophosphamide (CTX). Hepatoma 22 tumor-bearing mice were randomly divided into a vehicle group, CTX group, FZQJ group and combination (CTX+FZQJ) group. In addition, untreated mice without H22 cells served as blank controls. Seven days post-treatment, the mice were sacrificed and the tumors were weighed. Blood cells were evaluated using an automatic hemocytometer analyzer and flow cytometer. The expression levels of interleukin (IL)-2 and tumor necrosis factor (TNF)-α were evaluated using a radioimmunoassay. Apoptotic cells were observed using a terminal deoxynucleotidyl transferase dUTP nick-end labeling assay. Alanine transaminase, aspartate aminotransferase, blood urea nitrogen and creatinine were examined using an automatic biochemical analyzer. The results demonstrated that the tumor inhibitory rate and apoptosis index were higher in the combination group, compared with those in the CTX group. Notably, FZQJ was able to alleviate CTX-induced decreases in the numbers of white blood cells and platelets, CD3+ and CD4+ T lymphocyte subsets, and the concentration of hemoglobin, body weight and thymus index, and increase serum TNF-α and IL-2 levels without overt hepatorenal toxicity. These results suggest that FZQJ granules may enhance the anticancer effect of CTX, in addition to alleviating the side effects.

Fuzheng Qingjie recipe induces apoptosis in HepG2 cells via P38 MAPK activation and the mitochondria-dependent apoptotic pathway.

Fuzheng Qingjie (FZQJ) recipe is a polyherbal Chinese medicine capable of suppressing tumor growth and is used as an adjuvant therapy for various types of cancer. However, its anticancer mechanisms are yet to be fully elucidated. In the present study, we explored whether p38 mitogen-activated protein kinase (MAPK) was involved in FZQJ-mediated mitochondria-dependent apoptosis in human hepatocellular carcinoma cells. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays were used to measure the viability of HepG2 cells. 4,6-Diamidino-2-phenylindole (DAPI) and Annexin-V fluorescein isothiocyanate (FITC) were used to analyze the apoptosis of HepG2 cells. The mitochondrial membrane potential (∆ψ) and phosphorylated P38 MAPK protein were examined by a flow cytometer following 5,5',6,6'-tetrachloro­1,1',3,3'-tetraethylbenzimidazolcarbocyanine iodide (JC-1) and Alexa Fluor® 647 mouse anti-phosphorylated P38 MAPK antibody staining, respectively. The activation of caspase-9 and caspase-3 were measured using colorimetric assays. Additionally, Bcl-2 and Bax expression were examined using reverse transcription polymerase chain reaction (RT-PCR) and western blot analysis. The results demonstrated that water extract of FZQJ was able to induce apoptosis of HepG2 cells in vitro. FZQJ-induced apoptosis was accompanied by the loss of ∆ψ, downregulation of Bcl-2 and upregulation of Bax expression, and the activation of caspase-3, -9 and P38 MAPK. These results indicated that FZQJ induced apoptosis in HepG2 cells at least via P38 MAPK activation and the mitochondria-dependent apoptotic pathway.

Ethyl acetate extract from Jiedu Xiaozheng Yin inhibits the proliferation of human hepatocellular carcinoma cells by suppressing polycomb gene product Bmi1 and Wnt/ß-catenin signaling.

Jiedu Xiaozheng Yin (JXY) is a Chinese herbal decoction used to treat hepatocellular carcinoma (HCC). Previous studies have demonstrated that JXY can inhibit HCC cell proliferation via induction of G0/G1 phase arrest. In this study, we investigated whether the inhibitory effect of JXY on HCC cells is associated with the inhibition of the Wnt/ß­catenin pathway and the polycomb gene product Bmi1. Ethyl acetate extract from JXY (EE-JXY) was prepared. Methyl thiazolyl tetrazolium (MTT) and colony formation assays were used to measure cell proliferation. Immunofluorescence was used to analyze the expression and location of ß-catenin and Bmi1. Immunohistochemistry was used to examine the expression of proliferating cell nuclear antigen (PCNA), c-myc and cyclin D1. ß-catenin, Bmi1, c-myc, cyclin D1 and p16INK4A mRNA levels were detected by RT-PCR. The results demonstrated that EE-JXY inhibited the expression of PCNA, c-myc, cyclin D1 and Bmi1, and upregulated the expression of p16INK4A. We also found that EE-JXY could facilitate ß-catenin translocation from the cytoplasm and nuclei to the cytomembrane. Finally, suppression of cell proliferation and expression of Bmi1 and Wnt/ß-catenin by EE-JXY was confirmed in a mouse xenograft model of HCC. Thus, EE-JXY can inhibit the proliferation of HCC partially via suppression of the Bmi1 and Wnt/ß-catenin signaling pathways.

Water extract of Hedyotis Diffusa Willd suppresses proliferation of human HepG2 cells and potentiates the anticancer efficacy of low-dose 5-fluorouracil by inhibiting the CDK2-E2F1 pathway.

Hedyotis Diffusa Willd (HDW), a Chinese herbal medicine, has been widely used as an adjuvant therapy against various cancers, including hepatocellular carcinoma (HCC). However, the underlying anticancer mechanisms are yet to be elucidated. In the present study, the anticancer effects of HDW were evaluated and the efficacy and safety of HDW combined with low-dose 5-fluorouracil (5-FU) were investigated. HepG2 cells were cultured in vitro and nude mouse xenografts were established in vivo. The proliferation of HepG2 cells was measured using the MTT method and flow cytometry. The mRNA and protein expression levels of cyclin-dependent kinase 2 (CDK2), cyclin E and E2F1 were examined using relative quantitative real-time PCR and western blot analysis, respectively. The results showed that water extract of HDW remarkably inhibited HepG2 cell proliferation in a dose-dependent manner via arrest of HepG2 cells at the G0/G1 phase and induction of S phase delay. This suppression was accompanied by a great decrease of E2F1 and CDK2 mRNA expression. In addition, HDW remarkably potentiated the anticancer effect of low-dose 5-FU in the absence of overt toxicity by downregulating the mRNA and protein levels of CDK2, cyclin E and E2F1. Our findings support the use of HDW as adjuvant therapy of chemotherapy and suggest that HDW may potentiate the efficiency of low-dose 5-FU in treating HCC.