Objective To analyze the dynamic changes to disease activity,colonic inflammation,histopathology,and serum cytokine levels in mice with chronic ulcerative colitis(UC).Methods For UC induction,2.5％dextran sodium sulfate solution was provided ad libitum for 5 days,and to model remission,tap water was supplied for another 5 days in one induction cycle.Disease activity index(DAI),colon length,and pathological changes to colon tissue were determined.The levels of myeloperoxidase(MPO)in colon tissue and of cytokines such as IL-1 β in serum and colon were detected.Results During the three cycles,disease activity was aggravated and colon length shortened in mice during the induction periods,both of which were relieved during the remission periods.The blood appeared was observed in the stool was earlier in cycles 2 and 3.The number of mice with stool blood increased,and their body weight decreased by a small amount briefly,then recovered rapidly.The degree of histopathological damage to the colon and MPO content in cycles 1 and 3 increased in the induction periods and decreased in the remission periods,with the magnitude of change smaller than that of the change in DAI values;and they increased in the remission period of cycle 2.During induction,the spleen index and serum levels of IL-1β,IL-6,and IL-17A increased continuously and were higher than those in the control group at the end of the experiment.Levels of TNF-α were increased in the induction periods and decreased in the remission periods,and the trend in IL-10 change was similar to that of TNF-α.TGF-β content increased and then decreased and was higher than that in the control group at the end of cycle 3.The colon contents of IL-1β,IL-6,and IL-17A showed similar trends of increasing and then decreasing,but there was no significant change in colon TNF-α.The concentration of IL-10 decreased during the induction periods and increased during the remission periods.Conclusions During the induction of chronic UC in mice,the symptoms of hematochezia and systemic inflammatory reactions gradually increased,and the mice showed an increase in tolerance and ability to resist mortality,weight loss,and histopathological injury to the colon.The onset and remission of colonic histopathological damage lags behind symptomatic changes,and there is a gradual shift in colonic inflammation to a pattern dominated by polymorphonuclear neutrophils(PMN)activation.

With the continuous research on nanotechnology, nanosensors for the detection of various biomolecular have emerged one after another. As one of the main nanosensors, quantum dots have unique optical and particle properties, and quantum dot probes for pathogen detection have been widely used. The emerging fluorescent biomarkers, quantum dot probes, have unparalleled advantages over other fluorescent probes, such as strong fluorescence signal, good photostability, long fluorescence lifetime, and large Stokes shift. They can detect the target simply, quickly, sensitively and specifically. This article provides an overview of the basic properties of quantum dots and the application foundation of quantum dot probes as detection sensors. We focus on the types and preparation method of quantum dot probes, as well as their applications in pathogen detection in recent years. Finally, the application precautions of quantum dot probes as detection sensors were summarized, and the application prospects of quantum dot probes in the field of pathogen detection were also discussed.

Objective:To explore the effect of significant variation in non-structural protein 1 (NSP1) of 2019 novel coronavirus (2019-nCoV) on binding to 5′UTR, and to provide clues for the development of antiviral drugs and vaccines.Methods:The bioinformatics analysis of 2019-nCoV genome database was conducted to select the amino acid variation sites (T12A, R124L, N128I, K141A, GHVMV82-86DEL and KSF141-143DEL) that may affect the structure of NSP1 and the ability binding to 5′UTR. PSIPRED online tool was used to analyze the secondary structure of the variants, mCSM-NA was used to predict their binding ability to RNA, and DynaMut webserver was used to analyze the influence of variants on protein stability. The variant plasmids were constructed and transfected into HEK-293T cells. The dual luciferase reporter gene assay and RNA binding protein immunoprecipitation (RIP) assay were used to detect the binding ability of the NSP1 variant for viral 5′UTR.Results:Bioinformatics analysis predicted that except for R124L mutation, the other five variants could change the secondary structure of protein, and the mutations of T12A, R124L, N128I and K141A could reduce the binding ability of RNA, while the mutations of T12A, R124L and N128I reduced the stability of protein. The experimental results showed that R124L, N128I, GHVMV82-86DEL and KSF141-143DEL significantly weakened the binding ability of NSP1 to 5′UTR.Conclusions:Some mutations or deletion of NSP1 amino acids could change the secondary structure and significantly weaken the binding ability of NSP1 to the 5′UTR, suggesting that the pathogenicity of the virus may be changed, which could provide a theoretical basis for the development of antiviral drugs and vaccines.

Objective:To establish a rapid, sensitive and specific detection method for important imported viruses based on the recombinase aided amplification (RAA) method and clustered regularly interspaced short palindromic repeats-associated protein 13a (CRISPR-Cas13a) system.Methods:In this study, we selected Japanese encephalitis virus (JEV), Yellow fever virus (YEV), West Nile virus (WNV), Middle East respiratory syndrome coronavirus (MERS-CoV)、Ebola virus (EBOV), Dengue virus (DENV), Rift Valley fever virus (RVFV), Zika virus (ZIKV) as subjects, and designed specific RAA primers and CRISPR RNA(crRNA). The sensitivity and specificity of the method were evaluated. We detected suspected clinical samples of dengue fever and compared with the fluorescent reverse transcriptase-polymerase chain reaction (RT-PCR) technology. Clinical simulation samples of the remaining seven viruses were also detected.Results:The RAA method combined with CRISPR-Cas13a can detect eight pathogens within 40-52 min at 39 ℃. The sensitivity was 1-10 copies/μl. There was no cross-reaction among eight viruses and all clinical samples could be detected by this method.Conclusions:The established RAA combined with CRISPR-Cas13a detection method can sensitively, specifically and quickly detect eight imported infectious disease pathogens.

COVID-19 ; Coronavirus Nucleocapsid Proteins ; Humans ; Nucleocapsid Proteins ; Phosphoproteins ; SARS-CoV-2

Objective:To establish a rapid method for detecting the activity of 2019-nCoV2.Methods:The reverse transcription-quantitative polymerase chain reaction (RT-qPCR) detection system was screened after propidium monoazide (PMA) treatment and exposure to heat-inactivated 2019-nCoV samples, and the PMA pretreatment conditions were optimized to establish the 2019-nCoV PMA-RT-qPCR detection method . The established method was used to detect virus inactivated by different temperatures and chlorine-containing disinfectant, to evaluate its effect in detecting virus activity.Results:For the PMA-RT-qPCR assay, 200 μmol/L of PMA, 10 min of incubation time, 15 min of exposure time, and the CDC ORF1ab detection system were selected; there was no significant difference in the result of PMA-RT-qPCR and direct RT-qPCR for the active virus; the Ct values of PMA-RT-qPCR for virus inactivated by 95 ℃ and chlorine-containing disinfectant were higher than that of control groups at different dilutions; only partial dilutions of 70 ℃ and 56 ℃ heat-inactivated virus had higher Ct values than control groups. Conclusions:The established PMA-RT-qPCR for 2019-nCoV activity detection method has a good detection effect on the virus inactivated by 95 ℃ heat and chlorine disinfectant, and provides an auxiliary means for judging the infectivity of the virus in the sample.

Breast cancer is a malignant tumor originating from breast epithelial tissue. Ferroptosis is a novel type of programmed cell death which differs from apoptosis and necrosis. Research found that the accumulation of lipid peroxides in cells, a crucial process of ferroptosis, can be induced by multiple mechanisms. The ferroptosis regulation is closely related to the occurrence and development of breast cancer, and it induced by drugs is a potential and valuable research direction in breast cancer.

Objective:The entire genome sequences of 25 novel coronaviruses in Jiangsu province were analyzed and their evolutionary characteristics were studied.Methods:High-throughput sequencing was used to sequence the throat swab samples from confirmed cases. Single nucleotide polymorphisms were analyzed using CLC Genomics Workbench 12.0 software. Evolution characteristics were analyzed by MEGA 5.1.Results:A total of 52 single-base substitution mutations were detected in 25 strains. Phylogenetic analysis showed 25 stains were clustered into two clades. Viruses in clade 1 contain 8 682 and 28 144 CT SNP links. While viruses in clade 2 contain mutations in those two bases, i. e., 8 682 (ORF1ab: C8 517T, synonymous mutation) and 28 144 (ORF8: T251C, L84S). Among clade 2, five stains subclustered into one group based on SNP links in 24 034 (S: C2 472T, synonymous mutation), 26 729 (M: T207C, synonymous mutation), and 28 077 (ORF8: G184C, V62 L). There were no significant differences in the distribution of different clades/subclusters in the population and the disease types.Conclusions:We have found some SNPs occurred in new coronaviruses. The effects of different SNPs on virus transmission and pathogenicity need to be further studied.

Objective: To analyze the clinical manifestations and results of etiological examinations of 17 elderly patients with influenza A (H1N1) viral pneumonia, and to understand the clinical features of pneumonia and molecular characteristics of influenza A (H1N1) virus infection in the elderly. Methods: The elderly patients with pneumonia who were hospitalized in the Department of Respiratory Diseases of Nanjing First Hospital from January 2018 to March were enrolled. The cases were confirmed by nucleic acid examination for influenza virus and the clinical data were collected. After the amplification of the whole genome of influenza virus, the high throughput sequencing and bioinformatics analysis were performed. Results: The mean age of the 17 enrolled patients was 73.8±10.8. All of them had at least 1 underlying disease, and 7 cases had co-infection. Respiratory symptoms and fever were the most prominent clinical manifestations. Lesions in both lungs were found in 76.5% of the patients. The result of high throughput sequencing showed that all the viruses were highly homologous to the vaccine strain, and the HA gene belonged to the 6B.1 subgroup. Furthermore, three variations of antigenic locus (H138Y, S74R and S164T in HA) and a drug-resistant variation (H275Y in NA) were detected in the circulating strains. Conclusions Elderly patients with influenza A (H1N1) virus pneumonia often have underlying diseases and are prone to have co-infection. The molecular characteristics of the virus and the variation of key amino acid loci should be closely monitored in order to provide evidence for epidemic prevention and clinical antiviral treatment.

Adaptor Proteins, Signal Transducing ; chemistry ; genetics ; Crystallography, X-Ray ; Humans ; Nuclear Proteins ; chemistry ; genetics ; Protein Structure, Quaternary ; Protein Structure, Secondary ; Structure-Activity Relationship ; X-linked Nuclear Protein ; chemistry ; genetics