The potential role of the “cold chain” in the spread of SARS-CoV-2

Direct transmission of SARS-CoV-2 involves two main aspects:it can occur by inhaling either droplets or aerosols in the air containing viruses.In addition,viruses can also spread after being deposited on inanimate surfaces.Recently,there were reports suggested that SARS-CoV-2 can be found in frozen products.The cold chain creates opportunities for the spread of SARS-CoV-2.With the advent of winter,the drop in outside temperature makes the“frozen chain”less likely to be destroyed;thus,the virus will survive longer on frozen products.During the transportation of imported food,there is a greater risk of virus infection.Therefore,we should be vigilant and strengthen the quarantine of each type of imported food.

XpertMTB/RIF Assay for the Diagnosis of Pulmonary Tuberculosis Based on Bronchoalveolar Lavage Fluid:A Systematic Review and Meta-analysis

Currently,tuberculosis(TB)is the second most lethal disease in the world caused by a single infectious pathogen.Rapid diagnosis of TB is of great importance for its treatment and management.Xpert MTB/RIF is a novel rapid diagnostic assay for the diagnosis of pulmonary TB(PTB).Use of the Xpert assay based on bronchoalveolar lavage fluid(BALF)samples is indicated when TB is suspected and sputum smears or cultures are negative.The aim of this meta-analysis was to systematically evaluate the diagnostic performance of the Xpert assay based on BALF samples for the diagnosis of PTB.A systematic review of previously published articles was performed,and rel-evant data were extracted.Meta-DiSc 1.4 and Stata 12.0 were used to analyze the data.When Mycobacterium tuberculosis cultures were used as the criterion standard,the combined sensitivity of BALF-based Xpert was 0.89(95%CI,0.87–0.91),the specificity was 0.87(95%CI,0.85-0.88),the positive likelihood ratio was 8.28(95%CI,5.39–12.71),the negative likelihood ratio was 0.14(95%CI,0.10–0.19)and the diagnostic ratio was 84.08(95%CI,42.00–168.31).When composite reference standard was used as the criterion standard,the above observations were 0.69(95%CI,0.67–0.72),0.98(95%CI,0.97–0.98),41.40(95%CI,14.56–117.71),0.28(95%CI,0.21–0.37)and 190.47(95%CI,50.56–717.54),respectively.The area under the summary receiver operating characteristic curve was close to 1 for both.Overall,the Xpert MTB/RIF assay based on BALF samples showed high sensitivity and specificity for the diag-nosis of PTB and seems to be a reliable rapid detection method.

Assessing the Diagnostic Accuracy of SD BIOLINE for Detection of Hepatitis C Virus:A Systematic Review and Meta-analysis

Hepatitis C virus(HCV)is a globally widespread ribonucleic acid virus that transmits through blood and sexual contact.Its morbidity and mortality are particularly higher in economically underdeveloped areas.Therefore,an economical and effective diagnostic method for detection of HCV is urgently needed.In this study,we evaluated the diagnostic accuracy of the SD BIOLINE rapid diagnostic test for HCV detection.We searched for studies related to SD BIOLINE and HCV in PubMed,Embase,Web of Science,and the Cochrane Library and then designed inclusion and exclusion criteria.After extracting valid data,the included literature was evaluated with the quality assessment tool Quality Assessment of Diagnostic Accuracy Studies.After our data analysis,the sensitivity,specificity,positive likelihood ratio,negative likelihood ratio,diagnostic accuracy,summary receiver operating characteristic curve,funnel plot,box plot,and Fagan plot of the diagnosticmethod were determined.Nine articles with nine sets of data were finally included.The sensitivity and specificity were 0.94 and 0.98,respectively,the positive likelihood ratio was 79.53,the negative likelihood ratio was 0.05,the diagnostic odds ratio was 1590.32,and the summary receiver operating characteristic curve was 0.9958.The SD BIOLINE test has the advantages of high sensitivity,high specificity,low cost,and easy operation for diagnosing HCV.Therefore,we recommend using SD BIOLINE for rapid and effective screening of HCV,which is especially applicable for economically underdeveloped areas.

Cancer stem cell-mediated therapeutic resistance in hepatocellular carcinoma

Hepatocellular carcinoma(HCC)is a highly heterogeneous malignancy.In the clinic,therapeutic resistance is largely attributed to tumor heterogeneity.Growing evidence indicates that cancer stem cells(CSCs)are the major source of tumor heterogeneity.Hence,uncovering the resistance mechanisms associated with CSC properties is essential for developing effective therapeutics.CSCs resemble embryonic stem cells.Embryonic developmentrelated genes and signaling pathways are usually abnormally active and function as oncofetal drivers in HCC.Multiple strategies have been applied to identify oncofetal drivers.The mechanisms of CSC resistance could also provide reliable biomarkers to predict treatment failure.Precisely targeting these specific CSC properties may be effective in preventing or annihilating therapy resistance.This review provides an overview of drug resistance mechanisms associated with CSC traits and summarize therapeutic strategies against drug resistance.