Establishment and validation of the autophagy-related ceRNA network in irreversible pulpitis.

BACKGROUND: The molecular mechanisms underlying the onset and progression of irreversible pulpitis have been studied for decades. Many studies have indicated a potential correlation between autophagy and this disease. Against the background of the competing endogenous RNA (ceRNA) theory, protein-coding RNA functions are linked with long noncoding RNAs (lncRNAs) and microRNAs (miRNAs). This mechanism has been widely studied in various fields but has rarely been reported in the context of irreversible pulpitis. The hub genes selected under this theory may represent the key to the interaction between autophagy and irreversible pulpitis. RESULTS: Filtering and differential expression analyses of the GSE92681 dataset, which contains data from 7 inflamed and 5 healthy pulp tissue samples, were conducted. The results were intersected with autophagy-related genes (ARGs), and 36 differentially expressed ARGs (DE-ARGs) were identified. Functional enrichment analysis and construction of the protein‒protein interaction (PPI) network of DE-ARGs were performed. Coexpression analysis was conducted between differentially expressed lncRNAs (DElncRNAs) and DE-ARGs, and 151 downregulated and 59 upregulated autophagy-related DElncRNAs (AR-DElncRNAs) were identified. StarBase and multiMiR were then used to predict related microRNAs of AR-DElncRNAs and DE-ARGs, respectively. We established ceRNA networks including 9 hub lncRNAs (HCP5 and AC112496.1 ↑; FENDRR, AC099850.1, ZSWIM8-AS1, DLX6-AS1, LAMTOR5-AS1, TMEM161B-AS1 and AC145207.5 ↓), which were validated by a qRT‒PCR analysis of pulp tissue from patients with irreversible pulpitis. CONCLUSION: We constructed two networks consisting of 9 hub lncRNAs based on the comprehensive identification of autophagy-related ceRNAs. This study may provide novel insights into the interactive relationship between autophagy and irreversible pulpitis and identifies several lncRNAs that may serve as potential biological markers.

Stability of SARS-CoV-2 in cold-chain transportation environments and the efficacy of disinfection measures.

Background: Low temperature is conducive to the survival of COVID-19. Some studies suggest that cold-chain environment may prolong the survival of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and increase the risk of transmission. However, the effect of cold-chain environmental factors and packaging materials on SARS-CoV-2 stability remains unclear. Methods: This study aimed to reveal cold-chain environmental factors that preserve the stability of SARS-CoV-2 and further explore effective disinfection measures for SARS-CoV-2 in the cold-chain environment. The decay rate of SARS-CoV-2 pseudovirus in the cold-chain environment, on various types of packaging material surfaces, i.e., polyethylene plastic, stainless steel, Teflon and cardboard, and in frozen seawater was investigated. The influence of visible light (wavelength 450 nm-780 nm) and airflow on the stability of SARS-CoV-2 pseudovirus at -18°C was subsequently assessed. Results: Experimental data show that SARS-CoV-2 pseudovirus decayed more rapidly on porous cardboard surfaces than on nonporous surfaces, including polyethylene (PE) plastic, stainless steel, and Teflon. Compared with that at 25°C, the decay rate of SARS-CoV-2 pseudovirus was significantly lower at low temperatures. Seawater preserved viral stability both at -18°C and with repeated freeze-thaw cycles compared with that in deionized water. Visible light from light-emitting diode (LED) illumination and airflow at -18°C reduced SARS-CoV-2 pseudovirus stability. Conclusion: Our studies indicate that temperature and seawater in the cold chain are risk factors for SARS-CoV-2 transmission, and LED visible light irradiation and increased airflow may be used as disinfection measures for SARS-CoV-2 in the cold-chain environment.

The analytical strategy of GICA and CLIA combination in SARS-CoV-2 antibodies detection

To evaluate the effect of colloidal gold immunochromatographic assay (GCIA) combined with chemiluminescent immunoassay (CLIA) in reducing the false positive of antibodies against severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2). Thirty-three serum samples from 19 patients with SARS-CoV-2 infection at different times, and 55 serum samples from 55 patients not infected with SARS-CoV-2. but infected instead with other pathogens or suffering from autoimmune diseases were collected from the Affiliated Hospital of North Sichuan Medical College and Nanchong Central Hospital from 22 January to 5 March 2020. Serum IgM and IgG against SARS-CoV-2 were detected by GICA and CLIA respectively, and the results were analyzed. The sensitivity of GCIA for detection of IgM and IgG against SARS - CoV - 2 was 100.0% and 94.74%. respectively, values that were similar with those for CLIA (92.86% and 100.0%) (P = 1.000). The specificity of GCIA for IgM and IgG against SARS-CoV-2 was 70.91% and 74.55% respectively, which was significantly lower than that of CLIA (98.18% and 89.09%) (P < 0.01). The results of IgM and IgG against SARS-CoV-2 detected by the two methods were consistent (P=0.000) . and their Kappa was 0.434 and 0.406. respectively. Analyses of ROC curves showed that the AUC of IgM and IgG against SARS-CoV-2 detected by GCIA was 0.855 and 0.846. respectively, which was significantly lower than that of CLIA (0.955 and 0.945, respectively) (PC0.05). The sensitivity of combined detection of IgM and IgG against SARS -CoV-2 was 92.86% and 94.74%. and the specificity was 100.0% and 100.0%, respectively. Analyses of ROC curves showed that the AUC of combined detection of IgM and IgG against SARS-CoV-2 was 0.964 and 0.974. respectively, which was higher titan that of each method alone. GCIA combined with CLIA can improve the specificity of detection of IgM and IgG against SARS-CoV-2, which may merit clinical application.

Nucleic acid amplification with specific signal filtration and magnification for ultrasensitive colorimetric detection.

Recently, sensitive, fast and low cost nucleic acid isothermal amplification technologies (such as loop-mediated isothermal amplification, LAMP) have attracted great attention in the urgent needs of point-of-care testing (POCT) and regular epidemic prevention and control. However, unlike PCR which usually employs TaqMan probe to report specific signals, specific-signal-output strategies in isothermal amplification are immature and visual detection even rare, which limits their popularity in POCT. We hypothesize to address this issue by designing a visual-signal-report system to both filtrate and magnify the target information in isothermal amplification. In this work, we developed a specific signal filtration and magnification colorimetric isothermal sensing platform (SFMC for short) for ultrasensitive detection of DNA and RNA. SFMC consists of two processes: an isothermal amplification with specific signal filtration and a self-replication catalyzed hairpin assembly (SRCHA) for rapid target-specific signal magnification and outputting. With these unique properties, this biosensing platform could detect target DNA as low as 5 copies per reaction and target RNA as low as 10 copies per reaction by naked eyes. Benefited from the excellent colorimetric detection performance, this biosensing platform has been successfully used for African swine fever virus (ASFV) and SARS-CoV-2 detection.

Effect of urea dissociation on reducing the number of false-positive results of IgM and IgG antibodies against SARS-CoV -2

We wished to explore the interference factors causing false-positive results for immunoglobulin M (IgM) and IgG antibodies in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) detected by the gold immunochromatography assaym (GICA). In this way, we wanted to improve the detection method and scheme of laboratory detection. Seventy-four serum samples from outpatients and inpatients from the Affiliated Hospital of North Sichuan Medical College and Nanchong Central Hospital in China from 2 January 2020 to 5 March 2020 were collected 19 patients with the nucleic acids of SARS-CoV-2;10 cases with IgM antibodies against other respiratory viruses;10 patients with IgM antibodies against hepatitis viruses;20 patients with IgM antibodies against rheumatoid factor (RF);15 patients with antinuclear antibody (ANA). Colloidal GICA (kit A and kit B) was used to detect IgM and IgG antibodies against SARS-CoV-2 in patient sera. Positive results of SARS-CoV-2 IgM or SARS-CoV -2 IgG antibodies were analyzed, and possible factors causing false-positive results were found. Then, the sera of SARS- CoV - 2 IgM/IgG positive and 3 early coronavirus disease 2019 (COVID-19) patients were dissociated with an appropriate concentration of urea, and levels of IgM and IgG antibodies against SARS-CoV-2 were redetermined. SPSS v19.0 was used to analyze data. In the sera of 19 patients with SARS-CoV-2 infection 15 of SARS -CoV-2 IgM antibodies and 18 cases SARS-CoV-2 IgG antibodies were detected in kit A;12 cases of SARS-CoV-2 IgM antibodies and 12 cases of SARS-CoV-2 IgG antibodies were detected in kit B;16 cases of SARS-CoV-2 IgM antibodies and 14 cases of SARS-CoV -2 IgG antibodies were detected in 20 patients who had IgM antibodies against RF. In the sera of 15 patients with high - titer ANA, SARS-CoV- 2 IgG antibodies were detected in four cases using kit B. When the urea dissociation concentration was 2 mol/L, 14 of 16 RF- IgM - positive sera detected using kit A turned negative, 13 of 14 SARS- CoV- 2 IgG antibodies turned negative, but patients with COVID-19 detected by kit A did not show negative conversion of IgM or IgG antibodies. When the urea dissociation concentration was 4 mol/L, ANA -positive serum detected by kit B turned negative in four cases, whereas SARS-CoV-2 IgM and IgG antibodies in patients with COVID-19 did not turn negative. After urea dissociation, the SARS-CoV- 2 IgM antibodies detected by kit A and kit B in the sera of three patients with early COVID- 19 did not turn negative. RF could cause false-positive results for SARS-CoV-2 IgM and IgG antibodies detected by kit A, and a high titer of ANA could cause false-positive results of SARS-CoV-2 IgG antibodies detected by kit B. Urea dissociation could be helpful for reducing the probability of false-positive results of SARS-CoV-2 IgM and IgG antibodies. The effect of urea dissociation on the detection sensitivity of early COVID-19 merits further study.

Prevalence of Smell or Taste Dysfunction Among Children With COVID-19 Infection: A Systematic Review and Meta-Analysis.

Background: Smell and taste dysfunctions are common and have been reported as an early indicator of COVID-19. The prevalence of smell and taste dysfunctions among children with COVID-19 varies greatly across studies, which remains to be summarized quantitatively. This review aimed at examining the pooled prevalence of smell or taste dysfunctions among children with COVID-19, summarizing possible causes of the inconsistencies in the current estimates. Methods: Systematic searches of databases were conducted for literature published until 12 January 2021. Statistical analyses were performed using R software, the pooled prevalence was combined using random effects model. The Loney criteria were used for quality assessment. Results: A total of 18 eligible studies were included. The results showed that the pooled prevalence of smell dysfunction among children with COVID-19 was 15.97% (95% CI: 8.18-23.77%), the pooled prevalence of taste dysfunction among children with COVID-19 was 9.20% (95% CI: 4.25-14.16%), the pooled prevalence of smell or taste dysfunction among children with COVID-19 was 15.50% (95% CI: 10.30-20.70%) and the pooled prevalence of smell and taste dysfunction among children with COVID-19 was 20.21% (95% CI: 14.14-26.28%). Higher smell or taste dysfunction rates were associated with being female, younger age, smaller sample size, patients in Asia, and with comorbidities. Conclusions: Evidence suggests that smell or taste dysfunctions were common among children with COVID-19. Further research is needed to identify effective strategies for preventing and treating smell and taste dysfunctions among children with COVID-19.

The efficacy assessment of convalescent plasma therapy for COVID-19 patients: a multi-center case series.

Convalescent plasma (CP) transfusion has been indicated as a promising therapy in the treatment for other emerging viral infections. However, the quality control of CP and individual variation in patients in different studies make it rather difficult to evaluate the efficacy and risk of CP therapy for coronavirus disease 2019 (COVID-19). We aimed to explore the potential efficacy of CP therapy, and to assess the possible factors associated with its efficacy. We enrolled eight critical or severe COVID-19 patients from four centers. Each patient was transfused with 200-400 mL of CP from seven recovered donors. The primary indicators for clinical efficacy assessment were the changes of clinical symptoms, laboratory parameters, and radiological image after CP transfusion. CP donors had a wide range of antibody levels measured by serology tests which were to some degree correlated with the neutralizing antibody (NAb) level. No adverse events were observed during and after CP transfusion. Following CP transfusion, six out of eight patients showed improved oxygen support status; chest CT indicated varying degrees of absorption of pulmonary lesions in six patients within 8 days; the viral load was decreased to a negative level in five patients who had the previous viremia; other laboratory parameters also tended to improve, including increased lymphocyte counts, decreased C-reactive protein, procalcitonin, and indicators for liver function. The clinical efficacy might be associated with CP transfusion time, transfused dose, and the NAb levels of CP. This study indicated that CP might be a potential therapy for severe patients with COVID-19.

A Method To Prevent SARS-CoV-2 IgM False Positives in Gold Immunochromatography and Enzyme-Linked Immunosorbent Assays.

We set out to investigate the interference factors that led to false-positive novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) IgM detection results using gold immunochromatography assay (GICA) and enzyme-linked immunosorbent assay (ELISA) and the corresponding solutions. GICA and ELISA were used to detect SARS-CoV-2 IgM in 86 serum samples, including 5 influenza A virus (Flu A) IgM-positive sera, 5 influenza B virus (Flu B) IgM-positive sera, 5 Mycoplasma pneumoniae IgM-positive sera, 5 Legionella pneumophila IgM-positive sera, 6 sera of HIV infection patients, 36 rheumatoid factor IgM (RF-IgM)-positive sera, 5 sera from hypertensive patients, 5 sera from diabetes mellitus patients, and 14 sera from novel coronavirus infection disease 19 (COVID-19) patients. The interference factors causing false-positive reactivity with the two methods were analyzed, and the urea dissociation test was employed to dissociate the SARS-CoV-2 IgM-positive serum using the best dissociation concentration. The two methods detected positive SARS-CoV-2 IgM in 22 mid-to-high-level-RF-IgM-positive sera and 14 sera from COVID-19 patients; the other 50 sera were negative. At a urea dissociation concentration of 6 mol/liter, SARS-CoV-2 IgM results were positive in 1 mid-to-high-level-RF-IgM-positive serum and in 14 COVID-19 patient sera detected using GICA. At a urea dissociation concentration of 4 mol/liter and with affinity index (AI) levels lower than 0.371 set to negative, SARS-CoV-2 IgM results were positive in 3 mid-to-high-level-RF-IgM-positive sera and in 14 COVID-19 patient sera detected using ELISA. The presence of RF-IgM at mid-to-high levels could lead to false-positive reactivity of SARS-CoV-2 IgM detected using GICA and ELISA, and urea dissociation tests would be helpful in reducing SARS-CoV-2 IgM false-positive results.