The effect of influenza A (H1N1) pdm09 virus infection on cytokine production and gene expression in BV2 microglial cells.

Acute influenza infection has been reported to be associated with neurological symptoms such as influenza-associated encephalopathy (IAE). Although the pathophysiology of this condition remain unclear, neuroinflammation and associated alterations in the central nervous system (CNS) are usually induced. Microglia (MGs), CNS-resident macrophages, are generally the first cells to be activated in response to brain infection or damage. We performed reverse transcriptase droplet digital PCR (RT-ddPCR) and luminex assays to investigate virus proliferation and immune reactions in BV2 MGs infected with influenza A(H1N1)pdm09 virus. Furthermore, isobaric tags for relative and absolute quantitation (iTRAQ)-based quantitative proteomics methods were used to investigate the dynamic change in the protein expression profile in BV2 MGs to gain insight into the CNS response to influenza A (H1N1) pdm09 infection. Our results showed that the influenza A(H1N1)pdm09 virus was replicative and productive in BV2 MG cells, which produced cytokines such as interleukin (IL)-1ß, IL-6, tumour necrosis factor (TNF)-α and monocyte chemoattractant protein (MCP)-1. The expression of osteopontin (OPN) in the influenza A (H1N1) pdm09-infected BV2 MGs was upregulated at 16 and 32 h post-infection (hpi) compared to that in the control group, resulting in aggravated brain damage and inflammation. Our study indicates that OPN signalling might provide new insights into the treatment of CNS injury and neurodegenerative diseases in IAE.

Molecular epidemiology of enteroviruses associated with severe hand, foot and mouth disease in Shenzhen, China, 2014-2018.

In this study, we investigated the epidemiology and molecular characteristics of enteroviruses associated with severe hand, foot and mouth disease (HFMD) in Shenzhen, China, during 2014-2018. A total of 137 fecal specimens from patients with severe HFMD were collected. Enterovirus (EV) types were determined using real-time reverse transcription polymerase chain reaction (RT-PCR), RT nested PCR, and sequencing. Sequences were analyzed using bioinformatics programs. Of 137 specimens tested, 97 (70.8%), 12 (8.8%), and 10 (7.3%) were positive for EV-A71, coxsackievirus A6 (CVA6), and CVA16, respectively. Other pathogens detected included CVA2 (2.9%, 4/137), CVA10 (2.9%, 4/137), CVA5 (0.7%, 1/137), echovirus 6 (E6) (0.7%, 1/137) and E18 (0.7%, 1/137). The most frequent complication in patients with proven EV infections was myoclonic jerk, followed by aseptic encephalitis, tachypnea, and vomiting. The frequencies of vomiting and abnormal eye movements were higher in EV-A71-infected patients than that in CVA6-infected or CVA16-infected patients. Molecular phylogeny based on the complete VP1 gene revealed no association between the subgenotype of the virus and disease severity. Nevertheless, 12 significant mutations that were likely to be associated with virulence or the clinical phenotype were observed in the 5'UTR, 2Apro, 2C, 3A, 3Dpol and 3'UTR of CVA6. Eight significant mutations were observed in the 5'UTR, 2B, 3A, 3Dpol and 3'UTR of CVA16, and 10 significant mutations were observed in the 5'UTR, VP1, 3A and 3Cpro of CVA10. In conclusion, EV-A71 is still the main pathogen causing severe HFMD, although other EV types can also cause severe complications. Potential virulence or phenotype-associated sites were identified in the genomes of CVA6, CVA16, and CVA10.

Near-Complete Genome Sequences of 12 Coxsackievirus Group A Strains from Hand, Foot, and Mouth Disease and Herpangina Cases with Different Clinical Symptoms.

Coxsackievirus group A (CV-A) strains are important pathogens of hand, foot, and mouth disease and herpangina. We report here the near-complete genome sequences of 12 CV-A strains isolated from infants and children with different clinical diseases. The presented data will be very useful for future genome-based epidemiological studies.

Molecular surveillance of coxsackievirus A16 reveals the emergence of a new clade in mainland China.

Coxsackievirus A16 (CV-A16) of the genotypes B1a and B1b have co-circulated in mainland China in the past decades. From 2013 to 2017, a total of 3,008 specimens from 3,008 patients with mild hand, foot, and mouth disease were collected in the present study. Viral RNA was tested for CV-A16 by a real-time RT-PCR method, and complete VP1 sequences and full-length genome sequences of CV-A16 strains from this study were determined by RT-PCR and sequencing. Sequences were analyzed using a series of bioinformatics programs. The detection rate for CV-A16 was 4.1%, 25.9%, 10.6%, 28.1% and 12.9% in 2013, 2014, 2015, 2016 and 2017, respectively. Overall, the detection rate for CV-A16 was 16.5% (497/3008) in this 5-year period in Shenzhen, China. One hundred forty-two (142/155, 91.6%) of the 155 genotype B1 strains in the study belonged to subgenotype B1b, and 13 (13/155, 8.4%) strains belonged to subgenotype B1a. Two strains (CVA16/Shenzhen174/CHN/2017 and CVA16/Shenzhen189/CHN/2017) could not be assigned to a known genotype. Phylogenetic analysis of these two strains and other Chinese CV-A16 strains indicated that these two CV-A16 strains clustered independently in a novel clade whose members differed by 8.4%-11.8%, 8.4%-12.1%, and 14.6%-14.8% in their nucleotide sequences from those of Chinese B1a, B1b, and genotype D strains, respectively. Phylogenetic analysis of global CV-A16 strains further indicated that the two novel CV-A16 strains from this study grouped in a previously uncharacterized clade, which was designated as the subgenogroup B3 in present study. Meanwhile, phylogenetic reconstruction revealed two other new genotypes, B1d and B4, which included a Malaysian strain and two American strains, respectively. The complete genome sequences of the two novel CV-A16 strains showed the highest nucleotide sequence identity of 92.3% to the Malaysian strain PM-15765-00 from 2000. Comparative analysis of amino acid sequences of the two novel CV-A16 strains and their relatives suggested that variations in the nonstructural proteins may play an important role in the evolution of modern CV-A16.

Identification and characterization of the causative triatomine bugs of anaphylactic shock in Zhanjiang, China.

BACKGROUND: Two health concerns primarily related to triatomine bugs are transmission of Trypanosoma cruzi through infective feces, and allergic reactions induced by triatomine bites. In the Southwestern United States, reduviid bugs bites commonly cause insect allergy. In South China, four cases of anaphylactic shock have been reported after this bite exposure. To further classify the species of these bugs and confirm the sensitization of the triatomine saliva, we caught triatomine bugs from the region where the bites occurred and performed phylogenetic and immunohistochemical (IHC) analysis. METHODS: Triatomine bugs were collected in Donghai Island of Zhanjiang City in South China. The genomic DNA was extracted from three legs of the bugs. The fragments of mitochondrial 16S rRNA, cytochrome c oxidase subunit I (COI) gene and nuclear ribosomal 18S and 28S rRNA genes were obtained by PCR and sequenced. A phylogenetic tree was constructed based on the sequence of 16S rRNA gene using a maximum likelihood method with MEGA 7.0 software. Trypanosomal specific fragments and vertebrate COI genes were amplified from the fecal DNA to detect the infection of trypanosomes and analyze the blood feeding patterns, respectively. Paraffin-embedded sections were then prepared from adult triatomines and sent for IHC staining. RESULTS: We collected two adult triatomine bugs in Donghai Island. Morphological and molecular analyses indicated that the triatomines were Triatoma rubrofasciata. No fragments of T. cruzi or other trypanosomes were detected from the fecal DNA. Mitochondrial gene segments of Homo sapiens and Mus musculus were successfully amplified. The allergens which induced specific IgE antibodies in human serum were localized in the triatomine saliva by IHC assay. CONCLUSIONS: The two triatomine bugs from Donghai Island were T. rubrofasciata. They had bitten humans and mice. Their saliva should contain the allergens related to the allergic symptoms and even anaphylactic shock of exposed residents. Great consideration should be given to this triatomine bugs due to their considerable distribution and potential threat to public health in South China.

Complete Genome Sequence of an Enterovirus A71 Strain Isolated in 2006 from a Patient in Shenzhen, Southern China, with a Lethal Case of Enterovirus Infection.

The whole-genome sequence of an enterovirus A71 strain (EV71/SHENZHEN001/2006) isolated in 2006 from a patient with a fatal case of enterovirus infection was determined. Phylogenetic analysis based on the complete VP1 gene classified this strain as subgenotype C4a.

Complete Genome Sequences of Four Coxsackievirus A16 Strains Isolated from Four Children with Severe Hand, Foot, and Mouth Disease.

Here, we report the complete genome sequences of four coxsackievirus A16 strains isolated from four children with severe hand, foot, and mouth disease. Three of them were assigned to subgenotype B1b based on phylogenetic analysis of the VP1 gene, and the other one belonged to subgenotype B1a.

In Situ Bioorthogonal Metabolic Labeling for Fluorescence Imaging of Virus Infection In Vivo.

Optical fluorescence imaging is an important strategy to explore the mechanism of virus-host interaction. However, current fluorescent tag labeling strategies often dampen viral infectivity. The present study explores an in situ fluorescent labeling strategy in order to preserve viral infectivity and precisely monitor viral infection in vivo. In contrast to pre-labeling strategy, mice are first intranasally infected with azide-modified H5N1 pseudotype virus (N3 -H5N1p), followed by injection of dibenzocyclooctyl (DBCO)-functionalized fluorescence 6 h later. The results show that DBCO dye directly conjugated to N3 -H5N1p in lung tissues through in vivo bioorthogonal chemistry with high specificity and efficacy. More remarkably, in situ labeling rather than conventional prelabeling strategy effectively preserves viral infectivity and immunogenicity both in vitro and in vivo. Hence, in situ bioorthogonal viral labeling is a promising and reliable strategy for imaging and tracking viral infection in vivo.

Identification and Whole-Genome Sequencing of Four Enterovirus D68 Strains in Southern China in Late 2015.

Four enterovirus D68 (EV-D68) strains from four children with influenza-like illness were identified in Shenzhen, southern China, in late 2015. Here, we announce the availability of these viral genomes in GenBank. The genomic sequences of these EV-D68 strains showed the closest phylogenetic relationship to strains from northern China.

Development of Lateral Flow Immunoassay for Antigen Detection in Human Angiostrongylus cantonensis Infection.

Angiostrongyliasis is difficult to be diagnosed for the reason that no ideal method can be used. Serologic tests require specific equipment and are not always available in poverty-stricken zone and are time-consuming. A lateral flow immunoassay (LFIA) may be useful for angiostrongyliasis control. We established a LFIA for the diagnosis of angiostrongyliasis based on 2 monoclonal antibodies (mAbs) against antigens of Angiostrongylus cantonensis adults. The sensitivity and specificity were 91.1% and 100% in LFIA, while those of commercial ELISA kit was 97.8% and 86.3%, respectively. Youden index was 0.91 in LFIA and 0.84 in commercial ELISA kit. LFIA showed detection limit of 1 ng/ml of A. cantonensis ES antigens. This LFIA was simple, rapid, highly sensitive and specific, which opened an alternative approach for the diagnosis of human angiostrongyliasis.

Full-Genome Sequences of Seven Fatal Enterovirus 71 Strains Isolated in Shenzhen, China, in 2014.

The whole-genome sequences of seven fatal enterovirus 71 (EV71) strains, isolated in southern China, in 2014, were determined. The complete genome sequences of these strains displayed close relationships to native EV71 strains and showed 94.2% to 99.8% identity to each other. All of these strains were assigned to subgenotype C4a based on phylogenetic analysis of the VP1 gene.

Genomic characteristics of coxsackievirus A8 strains associated with hand, foot, and mouth disease and herpangina.

Coxsackievirus A8 (CV-A8), a member of the genus Enterovirus of the family Picornaviridae, can cause a variety of infectious diseases, such as hand, foot and mouth disease (HFMD), herpangina (HA), encephalitis, paralysis, myelitis, and meningitis. This is a first report of complete genome sequences of CV-A8 strains associated with HFMD/HA since the prototype strain Donovan was identified in 1949. The complete genome sequences of eight new CV-A8 strains showed 19.2 %-20.6 % nucleotide differences when compared to the prototype strain Donovan, and 81.5 %-99.9 % similarity to each other. The topology of a polyphyletic tree based on complete capsid protein gene sequences indicated that the new CV-A8 strains and Donovan are monophyletic. However, seven CV-A8 strains clustered with CV-A10 and CV-A2 in the 5'UTR and P2 region, respectively. In the P3 region, three and four CV-A8 strains grouped with CV-A6 and CV-A2, respectively. Seven CV-A8 strains segregated from Donovan and grouped in a separate lineage in the 3'UTR. The strain CVA8/SZ266/CHN/2014 was most similar to EV71 in the nonstructural proteins regions. Phylogenetic analysis classified worldwide CV-A8 isolates into four distinct clusters, and almost all Chinese and Thai CV-A8 strains evolved independently in their respective lineages, which indicated geographical evolution of CV-A8.

Genome-wide screen of promoter methylation analysis of ES cells and ES derived epidermal-like cells.

Embryonic stem cells (ESCs) are a population of pluripotent cells which can differentiate into different cell types. However, there are few reports with regard to differentiate ESCs into epidermal cells in vitro. In this study, we aimed to investigate differentially methylated promoters involved in process of differentiation from ESCs into epidermal-like cells (ELCs) induced by human amnion. We successfully induced ESCs into ELCs, which expressed the surface markers of CK19, CK15 and ß1-integrin. With MeDIP-chip arrays, we identified 3435 gene promoters to be differentially methylated, involving 894 HCP (high CpG-containing promoter), 974 ICP (intermediate CpG-containing promoter) and 1567 LCP (low CpG-containing promoter) among all the 17,500 DNA methylation regions of gene promoters in both ESCs and ELCs. Gene oncology and pathway analysis demonstrated that these genes were involved in all the three categories of GO enrichment analysis, including biological process, molecular function and cellular component. All these data suggested that embryonic stem cells can differentiate into epidermal-like cells and promoter methylation is of great importance in this process.

Whole-Genome Sequences of Two Rare Human Group C Rotavirus Strains Isolated from Two Cases of Acute Gastroenteritis.

This is a report of the complete genomic sequences of two rare group C rotavirus strains RVC/SZ94/CHN/2011 and RVC/SZ272/CHN/2011, isolated from two cases of acute gastroenteritis in Shenzhen, southern China, in 2011. These two strains display a close genetic relationship to 2007 Chinese strain YNR001 and 2008 Japanese strain BK0830.

Complete genome sequence of a coxsackievirus a16 strain, isolated from a fatal case in shenzhen, southern china, in 2014.

We determined the complete genome sequence of a coxsackievirus A16 strain (CVA16/SZ29/CHN/2014) from a fatal case in Shenzhen, southern China, in 2014. The strain was assigned to subgenotype B1b based on phylogenetic analysis of the VP1 gene.

Forecasting influenza epidemics from multi-stream surveillance data in a subtropical city of China.

BACKGROUND: Influenza has been associated with heavy burden of mortality and morbidity in subtropical regions. However, timely forecast of influenza epidemic in these regions has been hindered by unclear seasonality of influenza viruses. In this study, we developed a forecasting model by integrating multiple sentinel surveillance data to predict influenza epidemics in a subtropical city Shenzhen, China. METHODS: Dynamic linear models with the predictors of single or multiple surveillance data for influenza-like illness (ILI) were adopted to forecast influenza epidemics from 2006 to 2012 in Shenzhen. Temporal coherence of these surveillance data with laboratory-confirmed influenza cases was evaluated by wavelet analysis and only the coherent data streams were entered into the model. Timeliness, sensitivity and specificity of these models were also evaluated to compare their performance. RESULTS: Both influenza virology data and ILI consultation rates in Shenzhen demonstrated a significant annual seasonal cycle (p<0.05) during the entire study period, with occasional deviations observed in some data streams. The forecasting models that combined multi-stream ILI surveillance data generally outperformed the models with single-stream ILI data, by providing more timely, sensitive and specific alerts. CONCLUSIONS: Forecasting models that combine multiple sentinel surveillance data can be considered to generate timely alerts for influenza epidemics in subtropical regions like Shenzhen.

Derivation of human embryonic stem cell lines without any exogenous growth factors.

Human embryonic stem cell (hESC) lines are traditionally derived through immunosurgery. Their maintenance in culture requires the presence of mouse embryonic fibroblasts (MEFs) as feeder cells and media supplemented with basic fibroblast growth factor (bFGF) or other growth factors-both of which might introduce animal-derived culture components. The drawbacks associated with immunosurgery, MEF co-culture, and the cost of growth factors necessitate the exploration of a xeno-free method to maintain the self-renewal capacity of hESCs. Here, we describe an isolation method for the human inner cell mass (ICM), which was then cultured in the absence of exogenous growth factors and in the presence of human foreskin fibroblasts (HFFs) as feeder cells. Three hESC lines were obtained from poor-quality embryos by this near-xeno-free protocol. After culturing for more than 10 months, the hESCs retained normal morphology, expressed all expected cell surface markers, could differentiate to embryoid bodies upon culture in vitro, and formed teratomas in vivo. Furthermore, secretion of bFGF by HFFs was observed. In conclusion, this is the first study to describe an inexpensive, xeno-free culture system for the isolation and maintenance of hESCs that does not require bFGF supplementation.

Comparison of serum anti-Mullerian hormone levels following hysterectomy and myomectomy for benign gynaecological conditions.

OBJECTIVE: To compare serum anti-Mullerian hormone (AMH) levels following hysterectomy and myomectomy. STUDY DESIGN: Prospective longitudinal observational study. Serum AMH, follicle stimulating hormone (FSH) and luteinizing hormone (LH) levels were measured pre-operatively (T1) and 2 days (T2) and 3 months (T3) following hysterectomy and myomectomy in 70 women aged 36-45 years. Hysterectomy (laparoscopy-assisted vaginal hysterectomy=10; total abdominal hysterectomy=25) with conservation of both ovaries for benign diseases of the uterus was performed in 35 women, and myomectomy (laparoscopy myomectomy=15; open myomectomy=20) was performed in another 35 women. The follow-up period was 3 months following surgery. The results were analysed using the t-test or one-way analysis of variance by repeated-measures ANOVA. RESULTS: Serum AMH in the hysterectomy group was 1.08±0.77 ng/ml at T1, 0.78±0.58 ng/ml at T2 and 0.81±0.58 ng/ml at T3; the level was significantly lower at T2 and T3 compared with T1. In the myomectomy group, the corresponding values were 1.54±0.95 ng/ml, 1.18±0.77 ng/ml and 1.50±0.58 ng/ml; serum AMH was significantly lower at T2 compared with T1, but the difference between T3 and T1 was not significant. There were no significant differences in serum FSH and LH in either group between these three time points. CONCLUSION: Serum AMH was significantly lower 2 days and 3 months following hysterectomy compared with the pre-operative level. Following myomectomy, serum AMH was significantly lower than the pre-operative level 2 days following the procedure, but was similar to the pre-operative level 3 months after surgery. Therefore, hysterectomy may have a more lasting adverse effect on ovarian reserve than myomectomy. A long-term study of AMH levels is needed.

[Insulin-like growth factor-1 gene therapy improves the levels of mRNA and protein of endothelial nitric oxide synthase in aging related erectile dysfunction in rats].

OBJECTIVE: To explore the effects of gene transfer of insulin like growth factor-1 (IGF-1) on the penis of senile rats and the altered levels of mRNA and protein of endothelial nitric oxide synthase (eNOS). METHODS: Ten young (4 months) and 20 senile (24 months) Sprague-Dawley male rats were selected. The senile rats were divided into 2 groups: phosphate buffer solution (PBS)-only (n = 10) and 100 µg IGF-1 plasmid treatment group (n = 10). After a 4-week injection of IGF-1, the responses of intracavernous pressure (ICP) with electrical stimulation to the cavernous nerve and systemic mean arterial pressure (MAP) were evaluated. In the control and transfected senile rats, the levels of eNOS mRNA and protein were examined by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot respectively. RESULTS: The ICP/MAP and total ICP were significantly higher in the young control group versus the PBS-only group at Week 4 (P < 0.05). The ICP/MAP and total ICP were significantly higher in the young control group and the 100 µg IGF-1 treatment group versus the PBS-only group at Week 4 (P < 0.05). The levels of mRNA and protein of eNOS were higher in the 100 µg IGF-1 treatment group versus the PBS-only group at Week 4 (0.62 ± 0.16 vs 0.25 ± 0.08, 0.71 ± 0.19 vs 0.27 ± 0.09, both P < 0.05, respectively). CONCLUSION: The gene therapy of IGF-1 can ameliorate erectile functions and improve the levels of mRNA and protein of eNOS in senile rats.