[Influence of SARS-CoV-2 vaccination on the epidemiological and clinical characteristics of imported COVID-19 cases in Chengdu].

Objective: To analyze the epidemiological and clinical characteristics of imported COVID-19 cases after SARS-CoV-2 vaccination and to provide evidence for the prevention and control of COVID-19. Methods: The imported COVID-19 cases in Chengdu as of April 15, 2021 were divided into the vaccinated group and unvaccinated group according to the history of SARS-CoV-2 vaccination. The epidemiological and clinical data of the cases were collected retrospectively, and the differences in epidemiological and clinical characteristics of the two groups were compared. Laboratory tests consisted of nucleic acid test, clinical index test, serum antibody test and lymphocyte test. Software WPS2019 was used for data management and software R 4.0.3 was used for statistical analysis. Results: A total of 75 COVID-19 cases were included in the analysis, in which 20 had received SARS-CoV-2 vaccination and only 4 with clinical symptoms, 55 patients did not receive SARS-CoV-2 vaccination, and 16 had clinical symptoms. In vaccinated group, the first injection time of vaccination ranged from July to November 2020, and 10 cases received two doses of vaccine simultaneously and 10 cases received two doses of vaccine at intervals of 14-57 days. The intervals between the completion of vaccination and the onset ranged from 87 days to 224 days. The differences in classification and clinical type between the two groups were significant. Significant differences were observed in case classification and clinical type between vaccinated group and unvaccinated group (P<0.05). The vaccinated group had a relatively high proportion of asymptomatic infections (40.00%, 8/20), while mild infections were mainly observed in the unvaccinated group(76.36%,42/55). The differences in Ct values (ORF1ab gene and N gene) at the diagnosis were not significant between vaccinated group and unvaccinated group (P>0.05), similar results were also observed in lymphocyte subtypes, procalcitonin and C-reactive protein level comparisons. Serum amyloid A level was higher in unvaccinated group than in vaccinated group (P<0.05). However, the SARS-CoV-2 related serum antibody of IgM, IgG and total antibody levels were significantly higher in vaccinated group (P<0.05). Conclusions: Risk of infection still exists with SARS-CoV-2 after vaccination, which can facilitate the production of specific serum antibody of IgM and IgG when people are exposed to the virus. It has a certain protective effect on SARS-CoV-2 infected persons. Vaccination can reduce the clinical symptoms and mitigate disease severity.

MiRNA-485-5p, inhibits esophageal cancer cells proliferation and invasion by down-regulating O-linked N-acetylglucosamine transferase.

OBJECTIVE: Previous reports suggest that miRNA-485-5p is dysregulated and contributes to tumorigenesis in some cancer types. Nevertheless, the biological role of miRNA-485-5p in esophageal cancer (EC) is not well understood. Additionally, we found that the expression of miR-485-5p in EC tissues was aberrant. PATIENTS AND METHODS: Quantitative RT-PCR (qRT-PCR) was used to demonstrate the expression of miRNA-485-5p in EC cell lines. Cell counting kit-8 (CCK-8) assay and transwell assay indicated that miRNA-485-5p overexpression inhibited cell proliferation, migration, and invasion in EC cell lines. Additionally, Western blotting, dual-luciferase reporter assay, and rescue assay predicted that O-linked N-acetylglucosamine transferase (OGT) was a direct target of miRNA-485-5p. Moreover, we showed that miRNA-485-5p regulated EC tumorigenesis by down-regulating OGT expression in vitro and in vivo. RESULTS: The upregulation of miR-485-5p (fold change = 44 and 26 in ECA109 and TE-1, respectively; p<0.001) was showed by qRT-PCR. Compared with the control groups, the expression miR-485-5p significantly suppressed the proliferation, migration, and invasion of EC cells. The bioinformatic analysis predicted that the 3' untranslated region (UTR) of OGT contains one miR-485-5p target sequences. Western blotting and dual-luciferase reporter assay showed that activation of OGT 3'UTR was increased by co-transfection with miR-485-5p. Finally, CCK-8 assay predicted that the rescue effects of OGT expression on miR-485-5p induced inhibition of cell growth and tumor weight in Eca109 and TE1 cells. CONCLUSIONS: Our results suggest that miRNA-485-5p is a suppressor of EC tumorigenesis and could serve as a novel candidate for therapeutic applications in EC treatment.

Characterization and Mutational Analysis of Two UDP-Galactose 4-Epimerases in Streptococcus pneumoniae TIGR4.

Current clinical treatments for pneumococcal infections have many limitations and are faced with many challenges. New capsular polysaccharide structures must be explored to cope with diseases caused by different serotypes of Streptococcus pneumoniae. UDP-galactose 4-epimerase (GalE) is an essential enzyme involved in polysaccharide synthesis. It is an important virulence factor in many bacterial pathogens. In this study, we found that two genes (galEsp1 and galEsp2) are responsible for galactose metabolism in pathogenic S. pneumoniae TIGR4. Both GalESp1 and GalESp2 were shown to catalyze the epimerization of UDP-glucose (UDP-Glc)/UDP-galactose (UDP-Gal), but only GalESp2 was shown to catalyze the epimerization of UDP-N-acetylglucosamine (UDP-GlcNAc)/UDP-N-acetylgalactosamine (UDP-GalNAc). Interestingly, GalESp2 had 3-fold higher epimerase activity toward UDP-Glc/UDP-Gal than GalESp1. The biochemical properties of GalESp2 were studied. GalESp2 was stable over a wide range of temperatures, between 30 and 70°C, at pH 8.0. The K86G substitution caused GalESp2 to lose its epimerase activity toward UDP-Glc and UDP-Gal; however, substitution C300Y in GalESp2 resulted in only decreased activity toward UDP-GlcNAc and UDP-GalNAc. These results indicate that the Lys86 residue plays a critical role in the activity and substrate specificity of GalESp2.

Eco-friendly seeded Fe3O4-Ag nanocrystals: a new type of highly efficient and low cost catalyst for methylene blue reduction.

Hybrid Fe3O4-Ag nanocrystals, a new type of highly efficient and reusable catalyst for methylene blue (MB) reduction, are fabricated by a novel seed deposition process. X-ray diffraction and Mössbauer spectroscopy results show that the developed iron oxides are in a pure magnetite Fe3O4 phase. Upon manipulating the amount of Ag seeds capsuled on the modified surfaces of Fe3O4 nanocrystals, the catalytic capacities on the reduction of MB can be precisely adjusted with a tunable fabrication cost control. The linear correlation of the reduced MB concentration versus reaction time catalyzed by our developed hybrid Fe3O4-Ag nanocrystals is coherent with pseudo first order kinetics. Importantly, with remarkable recyclability features, the hybrid Fe3O4-Ag nanocrystals can be easily separated by applying an external magnetic field. The tailored catalytic performances of the hybrid Fe3O4-Ag nanocrystals during MB reduction are attributed to the optimized dynamic electron transfer process, which dominates the electrochemical mechanism wherein the nucleophilic BH4 - ions donate electrons to electrophilic organic MB through Ag seeds in a regulated amount. Such developed hybrid Fe3O4-Ag nanocrystals pave the way towards the mass production of highly efficient and low cost catalysts for methylene blue reduction.

[Clinical value of serum presepsin (SCD14-ST) concentration measurement in patients with pesticide poisoning].

OBJECTIVE: To investigate the value of serum presepsin concentration measurement in the clinical diagnosis and treatment of patients with pesticide poisoning patients. METHODS: A total of 160 patients with pesticide poisoning were enrolled as study subjects and divided into moderate organophosphate pesticide poisoning group (40 patients) , severe organophosphate pesticide poisoning group (40 patients) , abamectin pesticide poisoning group (40 patients) , and paraquat poisoning group (40 patients). A total of 20 healthy volunteers were enrolled as the control group. All the patients with poisoning received conventional treatment of pesticide poisoning immediately after admission, and serum presepsin concentration was measured on days 1 (within 24 hours after poisoning) , 3, and 7 of admission, and biochemical and radiological parameters related to the patient's condition were also examined. The patients with a Presepsin concentration of >800 pg/ml on day 1 of admission were randomly divided into conventional treatment group and ulinastatin treatment group, and the treatment outcome was compared between the two groups. RESULTS: Compared with the healthy control group, the groups with pesticide poisoning showed significant increases in serum Presepsin concentrations, with the highest degree of increase on day 1 (P <0.05). The serum Presepsin concentration was positively correlated with alanine aminotransferase, aspartate aminotransferase, creatine kinase, creatine kinase MB, lactate dehydrogenase, serum creatinine, blood urea nitrogen, interleukin-18, and white blood cell count, but negatively correlated with cholinesterase. In the conventional treatment group and ulinastatin treatment group, the overall response rate was 68% and 78.8%, respectively, with a significant difference between the two groups (P<0.05). In 40 patients with paraquat poisoning, 32 experienced an increase in serum presepsin concentration, and among these 32 patients, 27 (83%) experienced exudation on lung CT. CONCLUSION: Serum Presepsin concentration measurement can assist early diagnosis, evaluation of disease severity, and guidance for clinical medication in patients with pesticide poisoning, especially in those with severe pesticide poisoning and a tendency to multiple organ failure.

Synchrotron photoionization mass spectrometry study of intermediates in fuel-rich 1,2-dimethoxyethane flame.

Intermediates in a fuel-rich premixed laminar 1,2-dimethoxyethane (DME) flame are studied by molecular beam mass spectrometry combined with tunable synchrotron vacuum ultraviolet photoionization. About 30 intermediate species are identified in the present work, and their mole fraction profiles are evaluated. The experimental results show that the formations of intermediates, both hydrocarbons and oxygenated hydrocarbons, are closely linked to the structure of fuel, which is consistent with the previous reports. Species produced from H atom abstraction and beta scission of DME usually have much higher concentrations than others. The oxygen atoms in DME are considered to act as partitions of the primary intermediates; therefore farther reactions among these primary intermediates are difficult to occur, resulting in absence of most large intermediate species.