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Objective: To explore the epidemiological characteristic of a COVID-19 outbreak caused by 2019-nCoV Omicron variant BF.7 and other provinces imported in Shenzhen and analyze transmission chains and characteristics. Methods: Field epidemiological survey was conducted to identify the transmission chain, analyze the generation relationship among the cases. The 2019-nCoV nucleic acid positive samples were used for gene sequencing. Results: From 8 to 23 October, 2022, a total of 196 cases of COVID-19 were reported in Shenzhen, all the cases had epidemiological links. In the cases, 100 were men and 96 were women, with a median of age, M (Q1, Q3) was 33(25, 46) years. The outbreak was caused by traverlers initial cases infected with 2019-nCoV who returned to Shenzhen after traveling outside of Guangdong Province.There were four transmission chains, including the transmission in place of residence and neighbourhood, affecting 8 persons, transmission in social activity in the evening on 7 October, affecting 65 persons, transmission in work place on 8 October, affecting 48 persons, and transmission in a building near the work place, affecting 74 persons. The median of the incubation period of the infection, M (Q1, Q3) was 1.44 (1.11, 2.17) days. The incubation period of indoor exposure less than that of the outdoor exposure, M (Q1, Q3) was 1.38 (1.06, 1.84) and 1.95 (1.22, 2.99) days, respcetively (Wald χ2=10.27, P=0.001). With the increase of case generation, the number and probability of gene mutation increased. In the same transmission chain, the proportion of having 1-3 mutation sites was high in the cases in the first generation. Conclusions: The transmission chains were clear in this epidemic. The incubation period of Omicron variant BF.7 infection was shorter, the transmission speed was faster, and the gene mutation rate was higher. It is necessary to conduct prompt response and strict disease control when epidemic occurs.
Assuntos
Masculino , Humanos , Feminino , SARS-CoV-2 , COVID-19/epidemiologia , Surtos de Doenças , Epidemias , China/epidemiologiaRESUMO
Objective • To investigate the effect of albendazole (ABZ) on mouse femoral arteries restenosis and explore its possible mechanism. Methods • Vascular smooth muscle cells (VSMCs) were cultured in vitro with 0.5 and 1 μmol/L ABZ, and evaluated for cell proliferation, migration, and apoptosis by MTT, Transwell assay, and Annexin V-PI staining flow cytometry, respectively; and Western blotting was also used for the analysis of phosphorylation mechanism of cytoskeleton proteins cofilin (CFL) and myosin light chain (MLC). Stenosis was established in the unilateral femoral artery of 10-week-old wildtype male C57BL/6 mice by perivascular cuff placement and high fat chow breeding for 4 weeks. After successful modeling, mice were randomly divided into control group (equal volume of solvent) and ABZ group (1.5 mg/d) for gavage, and femoral arteries were collected 4 weeks later for H-E histological analysis of intimal area, medial area, and intima/media (I/M) ratio to clarify the severity of restenosis. Results • Both 0.5 and 1 μmol/L ABZ could significantly inhibit the proliferation and migration of VSMCs (both P<0.05), while 0.5 μmol/L had no significant effect on the apoptosis of VSMCs. ABZ gavage could significantly reduce the neointimal area and I/M ratio in the restenosis mice, while there were no effects on the median area. Both 0.5 and 1 μmol/L ABZ treatment could significantly inhibit CFL dephosphorylation and MLC phosphorylation, which showed a concentration-dependent trend (both P<0.05). Conclusion • ABZ inhibits VSMCs migration and intimal hyperplasia, via affecting the phosphorylation of cytoskeleton protein CFL and MLC, thereby resulting in therapeutic effects on restenosis of mice.
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OBJECTIVE: To determine the sequence of gene for encoding beta-lactamase produced by Klebsiella pneumoniae E3 isolated from Jiaxing Area in Zhejiang Province. METHODS The Klebsiella pneumoniae strain E3 was identified as an ESBLs-producing bacterium by inhibitor-potentiated broth dilution test. The gene encoding gamma-lactamase of the strain was amplified by PCR. The purified PCR product was cloned and sequenced by Sanger's dideoxy chain termination composition method. RESULTS The Klebsiella pneumoniae strain E3 produced both TEM and SHV gamma lactamases. The SHV encoding gene had 812 nucleotide residues responsible for encoding SHV-11 gamma-lactamase and the TEM encoding gene had 973 nucleotide residues responsible for encoding TEM-1 gamma-lactamase. CONCLUSION The Klebsiella pneumoniae strain E3 isolated from a patient in Jiaxing Area in Zhejiang Province is able to produce both TEM-1 and SHV-11 gamma-lactamases.