Isolation, characterization, and circulation sphere of a filovirus in fruit bats.

Bats are associated with the circulation of most mammalian filoviruses (FiVs), with pathogenic ones frequently causing deadly hemorrhagic fevers in Africa. Divergent FiVs have been uncovered in Chinese bats, raising concerns about their threat to public health. Here, we describe a long-term surveillance to track bat FiVs at orchards, eventually resulting in the identification and isolation of a FiV, Dehong virus (DEHV), from Rousettus leschenaultii bats. DEHV has a typical filovirus-like morphology with a wide spectrum of cell tropism. Its entry into cells depends on the engagement of Niemann-Pick C1, and its replication is inhibited by remdesivir. DEHV has the largest genome size of filoviruses, with phylogenetic analysis placing it between the genera Dianlovirus and Orthomarburgvirus, suggesting its classification as the prototype of a new genus within the family Filoviridae. The continuous detection of viral RNA in the serological survey, together with the wide host distribution, has revealed that the region covering southern Yunnan, China, and bordering areas is a natural circulation sphere for bat FiVs. These emphasize the need for a better understanding of the pathogenicity and potential risk of FiVs in the region.

Perceived Control, Control Strategies, and Subjective Well-being in the Elderly: A Longitudinal Study of Health Behavior.

Objectives: We analyzed the directional effect of perceived control and control strategies on subjective well-being in middle-aged and elderly people with historical data, and to provide data support for the intervention of well-being in the later years of the elderly group, so as to help them age successfully.Methods: Using data from the CLHLS between 2005 and 2014, we collected demographic and social data of the same elderly population over the decade. We also gathered information on changes in well-being, perceived control, and the use of control strategies. To analyze the longitudinal relationship between subjective well-being and perceived control, including the impact of control strategies on subjective well-being, we used a multilevel growth model with MPLUS. Results: We found that subjective well-being and perceived control were not affected by time. However, changes in perceived control in older adults could predict their level of subjective well-being. Those with higher initial levels of perceived control experienced greater increases in subjective well-being. Additionally, the use of control strategies had a significant influence on changes in subjective well-being, explaining 70.5% of the variance. Conclusion: Combined use of multiple control strategies is a feasible way to improve subjective well-being in later life.

Immunological characteristics of human umbilical cord mesenchymal stem cells after hepatogenic differentiation.

BACKGROUND: Acute liver failure is one of the most intractable clinical problems. The use of bioartificial livers may solve donor shortage problems. Human umbilical cord mesenchymal stem cells (hUCMSCs) are an excellent seed cell choice for artificial livers because they change their characteristics to resemble hepatocyte-like cells (HLCs) following artificial liver transplantation. OBJECTIVE: This study aimed to determine whether the immunological characteristics of hUCMSCs are changed after being transformed into hepatocyte-like cells. METHODS: HUCMSCs were isolated by the adherent method. The following hUCMSC surface markers were detected using flow cytometry: CD45, CD90, CD105, CD34, and octamer-binding transcription factor 4 (OCT-4). Functional detection of adipogenic differentiation was performed. The hUCMSCs were cultured in complete medium (control group) or induction medium (induction group), and flow cytometry was used to detect cell surface markers. Peritoneal lavage fluid was collected after intraperitoneal injection of 1 × 106 cells/mouse over 40 minutes. The leukocyte count, labeled CD45, CD3, CD4 and CD8 antibodies, and flow detection of T lymphocyte subsets were determined using the peritoneal lavage fluid. RESULTS: Using phenotypic and functional identification, hUCMSCs were successfully isolated using a two-step induction method. The surface markers of the hUCMSCs cells changed after HLC induction. In vivo immune results showed that hUCMSCs and HLsC induced leukocyte production. CONCLUSION: Hepatic induction of hUCMSCs changes their cell surface markers. Both HLCs and hUCMSCs cause leukocytosis in vivo, but the immune response induced by HLCs is slightly stronger.

Development and Prospect of Esophageal Tissue Engineering.

Currently, patients with esophageal cancer, especially advanced patients, usually use autologous tissue for esophageal alternative therapy. However, an alternative therapy is often accompanied by serious complications such as ischemia and leakage, which seriously affect the prognosis of patients. Tissue engineering has been widely studied as one of the ideal methods for the treatment of esophageal cancer. In view of the complex multi-layer structure of the natural esophagus, how to use the tissue engineering method to design the scaffold with structure and function matching with the natural tissue is the principle that the tissue engineering method must follow. This article will analyze and summarize the construction methods, with or without cells, and repair effects of single-layer scaffold and multi-layer scaffold. Especially in the repair of full-thickness and circumferential esophageal defects, the flexible design method and the binding force between the layers of the scaffold are very important. In short, esophageal tissue engineering technology has broad prospects and plays a more and more important role in the treatment of esophageal diseases.

Emergent chikungunya fever and vertical transmission in Yunnan Province, China, 2019.

During the dengue epidemic in Yunnan Province, China, during 2019, a concurrent outbreak of chikungunya occurred in the city of Ruili, which is located in the southwest of the province, adjacent to Myanmar. As part of this outbreak, three neonatal cases of infection with indigenous chikungunya virus from mother-to-child (vertical) transmission were observed. Isolates of chikungunya virus were obtained from 37 serum samples of patients with chikungunya during this outbreak, and a phylogenetic analysis of these isolates revealed that they belong to the Indian Ocean subclade of the East/Central/South African genotype. The E1 genes of these viruses did not harbor the A226V mutation.

Transcriptome-wide stability analysis uncovers LARP4-mediated NFκB1 mRNA stabilization during T cell activation.

T cell activation is a well-established model for studying cellular responses to exogenous stimulation. Motivated by our previous finding that intron retention (IR) could lead to transcript instability, in this study, we performed BruChase-Seq to experimentally monitor the expression dynamics of nascent transcripts in resting and activated CD4+ T cells. Computational modeling was then applied to quantify the stability of spliced and intron-retained transcripts on a genome-wide scale. Beyond substantiating that intron-retained transcripts were considerably less stable than spliced transcripts, we found a global stabilization of spliced mRNAs upon T cell activation, although the stability of intron-retained transcripts remained relatively constant. In addition, we identified that La-related protein 4 (LARP4), an RNA-binding protein (RBP) known to enhance mRNA stability, was involved in T cell activation-dependent mRNA stabilization. Knocking out Larp4 in mice destabilized Nfκb1 mRNAs and reduced secretion of interleukin-2 (IL2) and interferon-gamma (IFNγ), two factors critical for T cell proliferation and function. We propose that coordination between splicing regulation and mRNA stability may provide a novel paradigm to control spatiotemporal gene expression during T cell activation.

Underwater Target Localization and Synchronization for a Distributed SIMO Sonar with an Isogradient SSP and Uncertainties in Receiver Locations.

A distributed single-input multiple-output (SIMO) sonar system is composed of a sound source and multiple underwater receivers. It provides an important framework for underwater target localization. However, underwater hostile environments bring more challenges for underwater target localization than terrestrial target localization, such as the difficulties of synchronizing all the underwater receiver clocks, the varying underwater sound speed and the uncertainties of the locations of the underwater receivers. In this paper, we take the sound speed variation, the time synchronization and the uncertainties of the receiver locations into account, and propose the underwater target localization and synchronization (UTLS) algorithm for the distributed SIMO sonar system. In the distributed SIMO sonar system, the receivers are organized in a star topology, where the information fusion is carried out in the central receiver (CR). All the receivers are not synchronized and their positions are known with uncertainties. Moreover, the underwater sound speed is approximately modeled by a depth-dependent sound speed profile (SSP). We evaluate our proposed UTLS algorithm by comparing it with several benchmark algorithms via numerical simulations. The simulation results reveal the superiority of our proposed UTLS algorithm.

Non-small cell lung cancer harboring a rare EGFR L747P mutation showing intrinsic resistance to both gefitinib and osimertinib (AZD9291): A case report.

The most common EGFR mutations in non-small cell lung cancer are exon 19 deletions and exon 21 point mutations, which are both sensitive to EGFR-tyrosine kinase inhibitors. However, rare EGFR mutations do exist and how these mutations respond to tyrosine kinase inhibitors is not well understood. A Chinese woman diagnosed with stage IV lung adenocarcinoma harbored a rare EGFR L747P (2239-2240 TT > CC) mutation, and treatment with gefitinib and osimertinib failed to achieve the desired effect. Herein, possible correlations between gene analysis and the outcomes of subsequent treatment are discussed.

Comparative Evaluation of Three Preprocessing Methods for Extraction and Detection of Influenza A Virus Nucleic Acids from Sputum.

Viscous sputum specimens usually cannot undergo automated extraction, and thus, a pre-homogenization process is desirable before isolating nucleic acids for real-time reverse transcription PCR. In this study, we compared three preprocessing methods [preprocessing with normal saline (NS), dithiothreitol (DTT), and proteinase K (PK)] of sputum specimens on the extraction and detection of influenza A virus (IAV) nucleic acids. Based on the experimental results of 217 specimens, we found that DTT and PK could be used to improve the homogenization effects of sputum and increase the positive rates by 5.53-6.91% higher than that of the NS group. Comparison of 49 positive specimens in all of the three groups demonstrated that the threshold cycle values of the DTT group and PK group were significantly lower and their nucleic acid concentration and A260/A280 ratio within 1.8-2.0 were higher than those of the NS group. Thus, sputum homogenization before nucleic acid extraction is essential for the accurate diagnosis of IAV infection.

Monitoring the efficacy of infant hepatitis B vaccination and revaccination in 0- to 8-year-old children: Protective anti-HBs levels and cellular immune responses.

Vaccination against hepatitis B virus (HBV) is recommended worldwide. The aim of this study was to assess the efficacy of infant hepatitis B vaccination and revaccination in 0- to 8-year-old children in the context of protective anti-HBs levels and cellular immune responses. Using a random questionnaire survey, 1695 pre-school children were recruited as research subjects during January 2015 to June 2017. Blood samples were obtained to measure HBV serological markers as well as peripheral immunocytes. The children were divided into non-, low- and hyper- responsive groups (NR, LR, and HR) based on the vaccination efficacy. Additionally, the effect of revaccination on the NR group was evaluated at 1 month after completion of the vaccination course. Among a total of 1695 children, 1591 (93.86%) were infants who were followed while undergoing their primary course of hepatitis B vaccination at the 0-1-6 month schedule, and 1249 (79.30%) of them developed antibodies against HBsAg (anti-HBs) titers greater than 10 IU/L. The results of immunocyte studies indicated that the CD8+ T cells, CD4+CD45RO+ T cells, CD8+CD45RA+ T cells, and T follicular helper (Tfh) cells increased significantly in NR compared with HR. However, lymphocytes, CD4+ T cells, and CD4+CD45RA+ T cells in NR were lower than that in HR. 96 of the non-response cases showed seroprotection after revaccination among 103 cases. Therefore, most of the preschool children who received hepatitis B vaccine in infancy achieved significant seroprotection. Seroconversion rates of individuals revaccinated after initial vaccination failure were significantly higher than those after primary vaccination. Different vaccination efficacy groups showed significant changes in circulating immunocytes, which might be a factor affecting the recombinant HBV vaccine's immune effectiveness.

Benefit of Early Initiation of Neuraminidase Inhibitor Treatment to Hospitalized Patients With Avian Influenza A(H7N9) Virus.

Background: The significance of early neuraminidase inhibitor (NAI) therapy for treating influenza A(H7N9) is currently unknown. Methods: The duration of viral shedding was monitored by reverse-transcription polymerase chain reaction after patients with confirmed H7N9 infection were admitted to the First Affiliated Hospital, Zhejiang University, during April 2013-April 2017. Indices such as the length of hospitalization and mortality were collected, and the correlation between the time of administration of NAI and the severity of disease was systematically analyzed. Results: One hundred sixty patients with confirmed H7N9 infection were divided into 3 groups according to NAI starting time. Three of 20 (15%) patients for whom NAI was administered within 2 days died compared with 12 of 52 (23.1%) patients who received treatment within 2-5 days and 33 of 88 (37.5%) patients who were treated after 5 days (P < .05). The median durations of viral shedding from NAI therapy initiation was 4.5 days (interquartile range [IQR], 3-9 days) for patients who took antiviral medication within 2 days, which was significantly different from that for patients who took medication within 2-5 days (7.5 days [IQR, 4.25-12.75 days]) or after 5 days (7 days [IQR, 5-10 days]) (P < .05). We found that the duration of viral shedding from NAI therapy was the shortest in spring 2013 (5.5 days) and the longest in winter-spring 2016-2017 (8.5 days) (P < .05), showing a prolonged trend. Conclusions: Early NAI therapy within 2 days of illness shortened the duration of viral shedding and improved survival in patients with H7N9 viral infection.

Prevalence and genetic diversity of human diarrheagenic Escherichia coli isolates by multilocus sequence typing.

BACKGROUND: The population structure of human diarrheagenic Escherichia coli (DEC) isolates derived from worldwide collections remains undefined. METHODS: A total of 1196 clinical isolates were obtained from a multilocus sequence typing (MLST) database. Genetic diversity analysis, MLST analysis, and phylogenetic analysis combined with different pathotypes were performed through a variety of calculation software applications. RESULTS: All isolates were categorized as one of 579 different sequence types (STs). The eBURST algorithm resolved these 579 STs into 27 clonal complexes (CCs), 37 concatemers, and 210 singletons, revealing a high level of genetic diversity in the population structure of DEC. CC10 was the most prevalent CC, comprising 276 (23.08%, 276/1196) isolates with 85 (14.68%, 85/579) STs widely distributed in 20 countries. The population structure of five common pathotypes was highly diversified, and isolates with the same ST or CC were heterogeneous for different pathotypes. Sequence variations were more abundant in fumC and gyrB than in the other five genes, and these exhibited the highest degree of nucleotide diversity (0.03886 and 0.03075, respectively) and the greatest number of polymorphic nucleotide sites (137 and 139, respectively). The dN/dS ratios of seven analyzed loci varied from 0.0083 (recA) to 0.0434 (purA), and the ratio for the concatenated sequence was 0.2518, revealing the effects of purifying selection on housekeeping genes during the evolutionary process. Significant allele linkage disequilibrium was detected when the standardized index of association (ISA) was calculated both for the entire collection of isolates (0.3174, p<0.001) and for the 579 STs (0.1475, p<0.001). CONCLUSIONS: This study facilitated a comprehensive understanding of the genetic diversity of human DEC distributed across the global population. The results provide genetic evidence that will allow us to uncover the microevolutionary relationships among different pathogenic isolates of DEC.

Overexpression of SATB1 Gene Inhibits the Immunosuppressive Function of Regulatory T Cells in Chronic Hepatitis B.

Special AT-rich sequence-binding protein 1 (SATB1) is a class of nuclear matrix binding protein expressed by T cells and plays an important role in regulatory T cells (Tregs) mediated immune regulation. The immunosuppressive function of Tregs in chronic hepatitis B (CHB) being inhibited by SATB1 has been shown in our previous studies. The objective of this study was to learn the impact of SATB1 on the cellular immune function of CHB. SATB1 isolated from human peripheral blood mononuclear cells (PBMCs) was used as a template of PCR and its product was connected to vector PLV-EF1α-EGFP-N. Reconstructed vector PLV-EF1α-SATB1/EGFP was used to create highly infectious virions and then transduced to Tregs isolated from the CHB patients. Cytokine secreted by Tregs with and without SATB1 overexpression were determined. The results showed that there was a significant increase of Th1 (IFN-γ) and Th2 (IL-4 and IL-5) cytokines following SATB1 overexpression in CHB derived Tregs. It means that overexpression of SATB1 can promote the conversion from Tregs to effector T cells (Teffs) that lose suppressive function and stimulate the secretion of effective cytokines. These data provide the basis for further research on the mechanism of SATB1 in regulating specific immune response of CHB patients.

Surgery-induced monocytic myeloid-derived suppressor cells expand regulatory T cells in lung cancer.

While monocytic myeloid-derived suppressor cells (M-MDSCs) have been reported to induce the development of regulatory T cells (Treg), little is known about their correlation with Treg during perioperative period. Here, we demonstrated that the M-MDSCs expressing CD11b+CD33+HLA-DR-CD14+ in lung cancer patients after thoractomy significantly increased in comparison with preoperation, and their accumulation linearly correlated with an increase in Treg. Surgery-induced M-MDSCs, in addition to have high arginase activity, were more efficient in suppressing T-cell proliferation. Furthermore, the surgery-induced Treg expressed high levels of Foxp3, PD-1 and CTLA-4. Surgery-induced M-MDSCs were more potent in expending Treg when cocultured with autologous T cells in vitro. Using a lung metastasis mouse model, we demonstrated that the M-MDSCs at postoperative period were significantly increased and linearly correlated with Treg. We also showed that all-trans retinoic acid significantly inhibited the induction and proliferation of M-MDSCs, suppressed expansion of Treg, and finally prevented tumor metastasis in the mice after tumor resection. Receiver operating characteristic analyses revealed the superiority of surgery-induced M-MDSCs and Treg to those at preoperative period as a prognostic marker for lung cancer patients. Taken together, our results link the presence of surgery-induced M-MDSCs with the emergence of Treg and identify M-MDSCs and Treg derived postoperatively as potential indicators of tumor metastasis.

Increasing LAG-3 expression suppresses T-cell function in chronic hepatitis B: A balance between immunity strength and liver injury extent.

Weak or absent virus-specific CD8 T-cell responses to hepatitis B virus (HBV) infection are thought to be responsible for persistent HBV infection. Previous studies have indicated that multiple inhibitory receptors, including lymphocyte activation gene-3 (LAG-3), can suppress the CD8 T-cell response in chronic viral infection. This study aimed to detect LAG-3 expression and to investigate the manner in which the immune response is regulated to balance the strength of the response with the extent of liver injury in chronic HBV infection. The results showed that LAG-3 expression levels were significantly higher in CD8 T cells from chronic hepatitis B patients in the immune-active phase compared with chronic asymptomatic HBV carriers and healthy controls. CD8 T-cell function was suppressed in cells with high LAG-3 expression, and these cells exhibited reduced interferon-γ (IFN-γ) secretion. Furthermore, IFN-γ secretion was restored in CD8 T cells that were treated with a specific antibody to LAG-3. Taken together, liver injury was prominent in the immune-active phase, but suppressing T-cell function could mitigate this damage. Importantly, the inhibitory function of LAG-3 can be blocked using a LAG-3-specific antibody, and this can restore the activity of non-functional T cells.

Laboratory diagnosis and genetic analysis of a family clustering outbreak of aseptic meningitis due to echovirus 30.

Echovirus 30 (E30) is a major pathogen associated with aseptic meningitis. In the summer of 2014, a family clustering aseptic meningitis outbreak occurred in urban-rural fringe of Ningbo city in Zhejiang Province in China. To identify the etiologic agent, specimens were tested by cell culture and reverse transcriptase-polymerase chain reaction. Pathogenic examination confirmed that the outbreak is caused by E30. The first case is a 6-year-old child, who studied in kindergarten in local, suffered from headache and fever. Same symptoms appeared in his parents, aunts, and other six relatives continuously. Meanwhile, vomiting occurred in majority of the patients and diarrhea in parts of them. White blood cells in cerebrospinal fluid (CSF) exceeded normal range in all patients. Protein levels in CSF were above normal range in half of the patients. Glucose levels in CSF were within normal range in all patients. We isolated six strains E30 in the stool specimens of patients, and carried out sequencing analysis to VP1 region. Sequencing results showed that 100% sequence identity was seen in both nucleotide and amino acid levels. Phylogenetic analysis discovered that isolate in this study was grouped into sublineage D2 together with sequences isolated from other areas of China in the 2000s and 2010s. Our study is the first family clustering outbreak of aseptic meningitis caused by E30 in Zhejiang Province in China. It is essential to establish an enterovirus molecular surveillance system in China to prevent mass outbreaks in Zhejiang.

Enteropathogens in children less than 5 years of age with acute diarrhea: a 5-year surveillance study in the Southeast Coast of China.

BACKGROUND: Diarrhea is the second most common cause of death among children less than 5 years of age worldwide. The etiological agents of diarrhea in the southeast coastal area of China were studied from July 2009 to December 2014. METHODS: A total of the 2318 patients were enrolled in this study and examined for the presence of viruses, bacteria, and parasites. Multiplex real-time PCR was used for the detection of diarrheagenic Escherichia.coli (DEC). DEC strains were tested for susceptibility to a panel of 20 antibiotics using the Kirby-Bauer disc-diffusion method. RESULTS: Of the 2318 children with diarrhea, 962 (41.5 %) were positive for at least one pathogen. Rotavirus, human calicivirus (HucV), and DEC were predominant, with detection rates of 19.1 % (443), 17.7 % (411), and 7.6 % (177), respectively. The prevalences of various pathogens in patients of different ages and in different seasons were not the same. The resistance rates of 177 strains of DEC to ampicillin, tetracycline, and cefazolin were 93.2 %, 60.0 %, and 57.7 %, respectively. CONCLUSIONS: Rotavirus, HucV, and DEC were the main pathogens associated with diarrhea in Zhejiang, China. DEC possessed high levels of antibiotic resistance. Increased monitoring of etiological agents of diarrhea is necessary.

The influence of myeloid-derived suppressor cells on angiogenesis and tumor growth after cancer surgery.

While myeloid-derived suppressor cells (MDSCs) have been reported to participate in the promotion of angiogenesis and tumor growth, little is known about their presence and function during perioperative period. Here, we demonstrated that human MDSCs expressing CD11b(+), CD33(+) and HLA-DR(-) significantly increased in lung cancer patients after thoracotomy. CD11b(+) CD33(+) HLA-DR(-) MDSCs isolated 24 hr after surgery from lung cancer patients were more efficient in promoting angiogenesis and tumor growth than MDSCs isolated before surgical operation in allograft tumor model. In addition, CD11b(+) CD33(+) HLA-DR(-) MDSCs produced high levels of MMP-9. Using an experimental lung metastasis mouse model, we demonstrated that the numbers of metastases on lung surface and Gr-1(+) CD11b(+) MDSCs at postoperative period were enhanced in proportion to the degree of surgical manipulation. We also examined that syngeneic bone marrow mesenchymal stem cells (BMSCs) significantly inhibited the induction and proliferation of Gr-1(+) CD11b(+) MDSCs and further prevented lung metastasis formation in the mice undergoing laparotomy. Taken together, our results suggest that postoperatively induced MDSCs were qualified with potent proangiogenic and tumor-promotive ability and this cell population should be considered as a target for preventing postoperative tumor metastasis.

IL-35 inhibits HBV antigen-specific IFN-γ-producing CTLs in vitro.

Interleukin (IL)-35 is an inhibitory cytokine consisting of IL-12A and Epstein-Barr virus-induced gene 3 (Ebi3) and is required by regulatory T-cells (Tregs) for maximal activity. During chronic hepatitis B virus (HBV) infection, Tregs have immunosuppressive effects on HBV-specific T helper (Th) cells, yet little is known about the complex regulation of Tregs and their contribution to the inadequate immune system response to the virus. In the present study, we investigated whether IL-35 is involved in HBV-related cellular immune responses. Cluster of differentiation (CD)4(+) T-cells from peripheral blood were derived from healthy volunteers, resolved HBV individuals and chronic active hepatitis B patients and stimulated with CD3/28-conjugated beads. We analysed mRNA and protein levels of IL-35 and assessed the inhibitory effect of IL-35 on HBV core antigen-specific cytotoxic T lymphocytes (CTLs), dendritic cells (DCs) and effector T-cells (Teffs). Correlation analyses between liver inflammation and HBV DNA load were conducted. Results show that chronic HBV patients harbour significantly higher levels of Ebi3 mRNA and protein in CD4(+) T-cells compared with healthy volunteers and resolved HBV individuals. IL-35 suppressed the proliferation of HBV antigen-specific CTLs and interferon (IFN)-γ production in vitro. Ex vivo, IL-35 decreased the proliferation of CD4(+)CD45RA(+) naïve T-cells, especially in CD4(+)CD25(-)CD45RA(+) naïve Teffs. IL-35 inhibited the expansion of CD11c(+) DCs. Our data indicate that IL-35 is highly expressed in chronic HBV CD4(+) T-cells and plays an important role in the inhibition of the cellular immune response in chronic HBV.