Individual bat viromes reveal the co-infection, spillover and emergence risk of potential zoonotic viruses

Bats are reservoir hosts for many zoonotic viruses. Despite this, relatively little is known about the diversity and abundance of viruses within bats at the level of individual animals, and hence the frequency of virus co-infection and inter-species transmission. Using an unbiased meta-transcriptomics approach we characterised the mammalian associated viruses present in 149 individual bats sampled from Yunnan province, China. This revealed a high frequency of virus co-infection and species spillover among the animals studied, with 12 viruses shared among different bat species, which in turn facilitates virus recombination and reassortment. Of note, we identified five viral species that are likely to be pathogenic to humans or livestock, including a novel recombinant SARS-like coronavirus that is closely related to both SARS-CoV-2 and SARS-CoV, with only five amino acid differences between its receptor-binding domain sequence and that of the earliest sequences of SARS-CoV-2. Functional analysis predicts that this recombinant coronavirus can utilize the human ACE2 receptor such that it is likely to be of high zoonotic risk. Our study highlights the common occurrence of inter-species transmission and co-infection of bat viruses, as well as their implications for virus emergence.

Effects of Signaling Activation of Bone Morphogenetic Protein 2 on the Differentiation and Infiltration of Regulatory T Lymphocytes in Tumors / 中国医学科学院学报

Objective To determine whether the signaling activation of bone morphogenetic protein 2(BMP2)can induce myeloid-derived suppressor cells(MDSC)to secret transforming growth factor β(TGF-β),further enhancing the differentiation and infiltration of regulatory T lymphocytes(Treg)into tumor tissue. Methods The BMP2-induced mRNA and protein expression of TGF-β in MDSC was detected by quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay(ELISA),respectively.The effect of BMP2-induced TGF-β secretion by MDSC on Treg differentiation was then determined by flow cytometry.Finally,we implanted the recombined human bone morphogenetic protein 2(rhBMP2)collagen gels into tumor-burdened mice to examine the role of BMP2 in Treg differentiation via MDSC-secreted TGF-β

Broad phenotypic alterations and potential dysfunctions of lymphocytes in COVID-19 recovered individuals

BackgroundLymphopenia is a typical symptom in the COVID-19 patients. While millions of patients are clinical recovered, little is known about the immune status of lymphocytes in these individuals. MethodsA clinical recovered cohort (CR) of 55 COVID-19 individuals (discharged from hospital 4 to 11 weeks), and 55 age and sex matched healthy donors cohort (HD) were recruited. Detailed analysis on phenotype of the lymphocytes in peripheral blood mononuclear cells (PBMCs) was performed by flow cytometry. FindingsCompared with cohort HD, the CD8+ T cells in cohort CR had higher Teff and Tem, but lower Tc1 (IFN-{gamma}+), Tc2 (IL-4+) and Tc17 (IL-17A+) frequencies. The CD4+ T cells of CR had decreased frequency, especially on the Tcm subset. Moreover, CD4+ T cells of CR expressed lower PD-1 and had lower frequencies of Th1 (IFN-{gamma}+), Th2 (IL-4+), Th17 (IL-17A+) as well as circulating Tfh (CXCR5+PD-1+). Accordingly, isotype-switched memory B cell (IgM-CD20hi) in CR had significantly lower proportion in B cells, though level of activation marker CD71 elevated. For CD3-HLA-DRlo lymphocytes of CR, besides levels of IFN-{gamma}, Granzyme B and T-bet were lower, the correlation between T-bet and IFN-{gamma} became irrelevant. In addition, taken into account of discharged days, all the lowered function associated phenotypes showed no recovery tendency within whole observation period. InterpretationThe CR COVID-19 individuals still showed remarkable phenotypic alterations in lymphocytes after clinical recovery 4 to 11 weeks. This suggests SARS-CoV-2 infection imprints profoundly on lymphocytes and results in long-lasting potential dysfunctions. FundingKunming Science and Technology Department (2020-1-N-037)

[PM10 Concentration Forecasting Model Based on Wavelet-SVM].

PM10 is the main air pollutant in Taiyuan, as the city is a heavy industrial center with coal as its main energy source. Therefore, research on the prediction of this pollutant's variation and concentration is of great theoretical significance for air pollution prevention and emergency solutions. The source of PM10 is very complex, as it is affected by industrial emissions, vehicle exhaust, fugitive dust, and many other factors. The emission sources of PM10 are difficult to determine accurately. The goal of our research was to give accurate forecasting results efficiently when only time-series PM10 concentrations, and no other exogenous information, is available. A support vector machine (SVM) enjoys good generalization performance in the PM10 concentration forecasting area. Traditionally, an SVM chooses historical data as the input features in the process of dealing with the time-series data of air pollutant concentrations. However, data with simple structure and incomplete information have become the fetter of generalization ability improvement. In this study, the data for simulation experiments was the PM10 concentration dataset collected from four monitoring stations in Taiyuan. The PM10 concentration time-series one-dimension data was decomposed into high dimension, constructed by low frequency and high frequency series using a wavelet transform. The wavelet-SVM forecasting model can be established by introducing the high-dimension data as the input features. The experiment results indicate that, contrasted with the traditional SVM, the wavelet-SVM model boasts higher accuracy for PM10 concentration prediction. In particular, it captures the concentration mutational points more accurately and provides information support that is more effective for atmospheric pollution warning. In addition, with the wavelet-SVM model, prediction accuracy for the concentration variations was significantly improved and laws that were more inherent in the PM10 concentration time series were revealed.

Particulate matter (PM10) exposure induces endothelial dysfunction and inflammation in rat brain.

Epidemiological studies suggest that particulate matter (PM(10)) inhalation was associated with adverse effects on brain-related health, however, existing experimental data lacked relevant evidences. In this study, we treated Wistar rats with PM(10) at different concentrations (0.3, 1, 3 and 10 mg/kg body weight (bw)), and investigated endothelial dysfunction and inflammatory responses in the brain. The results indicate that mild pathological abnormal occurred after 15-day exposure (five times with 3 days each), followed by the changes of endothelial mediators (ET-1 and eNOS) and inflammatory markers (IL-1ß, TNF-α, COX-2, iNOS and ICAM-1). Also, the sample up-regulated bax/bcl-2 ratio and p53 expression, and induced neuronal apoptosis. It implicates that PM(10) exerted injuries to mammals' brain, and the mechanisms might be involved in endothelial dysfunction and inflammatory responses.

Comparison of mtDNA extracting methods for common sarcosaphagous insects / 法医学杂志

OBJECTIVE@#To compare effects of three different methods for mtDNA extraction from common sarcosaphagous insects including cetyl trimethyl ammonium bromide (CTAB) method, sodium dodecyl sulfate-potassium acetate (SDS-KAc) method and sodium dodecyl sulfate-proteinase K (SDS-PK) method.@*METHODS@#Seventy-two insects from four species [Chrysomya megacephala (Fabricius, 1784), Eusilpha bicolor (Fairmaire, 1896), Paraeutrichopus pecoudi (Mateu, 1954), Vespa velutina (Lepeletier, 1836)] were collected from the corpses of the rabbits in Changsha district. The total DNA of above samples was extracted by CTAB, SDS-Kac and SDS-PK methods. The purity and concentration of DNA were examined by protein-nucleic acid spectrophotometry, and mtDNA were amplified by specific primers and PCR products were detected by agarose gel electrophoresis. Then PCR products were sequenced and subsequently up-loaded to GenBank.@*RESULTS@#mtDNA was successfully extracted with three methods from most of the samples. The SDS-PK method was better in DNA purity compared to other methods and the CTAB method was superior in extracting DNA from old samples, while SDS-KAc method showed no significant difference for extraction effects of different samples.@*CONCLUSION@#The most appropriate method should be chosen depending on different situations. SDS-PK method is expected to obtain high-quality DNA, while CTAB method is preferred in extracting obsolete samples. SDS-KAc method is low cost and can be used in various kinds of preliminary experiments.

Advances in the studies of postmortem interval estimation by the levels of chemical components in human vitreous humor after death / 法医学杂志

Estimation of postmortem interval (PMI) is one of the problems that need to be solved for forensic examination of the dead body. Accurate estimation of PMI has great values to criminal investigation and trial. The levels of chemical components in human vitreous humor are changed with time after death, which can help estimate the PMI. The levels of certain chemical components, such as potassium, magnesium, ammonia, urea, creatinine, uric acid, hypoxanthine, lactic acid and so on, in human vitreous humor will gradually increase with time after death, while others such as calcium, sodium, enzymes, glucose, vitamin C and so on will decrease. The updates and advances in those studies were reviewed in this article.

Advances of forensic entomology in China / 法医学杂志

Forensic entomology is a branch of forensic medicine, which applies studies of insects and arthropods to getting evidence for court and has an analogous advantage in the estimation of the postmortem interval (PMI) and other questions of forensic relevance. The paper expounds its definition and contents and reviews some progress of the studies in some aspects in China such as the constitution and succession of insect community on the different cadavers, the applications of morphological features of insects and the technology of analysis of deoxyribonucleic acid (DNA) in forensic entomology, and forensic entomological toxicology etc.

Relationship between CO II gene of mtDNA of Lucilia sericata and latitude interval / 法医学杂志

OBJECTIVE@#To deduce the region that the geographical species of Lucilia sericata come from and determine the scene of crime (SOC) based on the gene analysis of mtDNA CO II.@*METHODS@#A 635 bp region for CO II of 4 Lucilia sericata (belong to 2 geographical species) were collected and sequenced, compared with the data of GenBank. A neighbour-joining tree with the Tamura and Nei model was constructed by MEGA2.1 package. The number of inherit intervals of inner-species were analyzes by Kimura's two-parameter model and used for construction the relationships between hereditary and latitude interval by SPSS10.5 soft.@*RESULTS@#It showed that they had the relationships between inherit and latitude interval for the 8 geographical species of Lucilia sericata for CO II.@*CONCLUSION@#This method can be the evidence deducing the region that the geographical species of Lucilia sericata come from and further to determine the scene of crime (SOC).