634 research outputs found

    Mice as an Animal Model for Japanese Encephalitis Virus Research: Mouse Susceptibility, Infection Route, and Viral Pathogenesis

    Get PDF
    Japanese encephalitis virus (JEV), a zoonotic flavivirus, is principally transmitted by hematophagous mosquitoes, continually between susceptible animals and incidentally from those animals to humans. For almost a century since its discovery, JEV was geographically confined to the Asia-Pacific region with recurrent sizable outbreaks involving wildlife, livestock, and people. However, over the past decade, it has been detected for the first time in Europe (Italy) and Africa (Angola) but has yet to cause any recognizable outbreaks in humans. JEV infection leads to a broad spectrum of clinical outcomes, ranging from asymptomatic conditions to self-limiting febrile illnesses to life-threatening neurological complications, particularly Japanese encephalitis (JE). No clinically proven antiviral drugs are available to treat the development and progression of JE. There are, however, several live and killed vaccines that have been commercialized to prevent the infection and transmission of JEV, yet this virus remains the main cause of acute encephalitis syndrome with high morbidity and mortality among children in the endemic regions. Therefore, significant research efforts have been directed toward understanding the neuropathogenesis of JE to facilitate the development of effective treatments for the disease. Thus far, multiple laboratory animal models have been established for the study of JEV infection. In this review, we focus on mice, the most extensively used animal model for JEV research, and summarize the major findings on mouse susceptibility, infection route, and viral pathogenesis reported in the past and present, and discuss some unanswered key questions for future studies

    Seismic performance of reinforced concrete frames retrofitted with inserted steel frame and adhered waved steel panel

    Get PDF
    In this paper, two types of seismic retrofitting methods for reinforced concrete frames were suggested and examined through the cyclic loading tests: one is to insert a steel frame to existing partially masonry infilled concrete frame of the building after removing masonry from the concrete frame and the other is to adhere waved steel panels to the existing masonry fully infilled concrete frame. In order to evaluate validity of the suggested methods in seismic performance, five specimens were manufactured and tested: a bare concrete frame, a partially masonry infilled concrete frame, a masonry infilled concrete frame, a steel frame inserted concrete frame, and a waved steel panel adhered concrete frame. Compared were crack pattern, failure mode, load-displacement relation, ductility, stiffness and energy dissipation capacity. The specimens retrofitted with the inserted steel frame showed a maximum load approximately twice that of the partially masonry infilled frame, and the specimen retrofitted with the adhered waved steel panel showed a maximum load approximately twice that of the masonry fully infilled frame

    Generation of Polyclonal Rabbit Antisera Specific to the Zika Virus Capsid Protein

    Get PDF
    Zika virus (ZIKV), a mosquito-borne flavivirus, is an emerging zoonotic pathogen closely related to Japanese encephalitis virus, West Nile virus, dengue virus, and yellow fever virus. Although ZIKV infection generally produces only mild symptoms in some infected individuals, it has recently been associated with a growing number of neurological diseases, including Guillain-Barré syndrome in ZIKV-infected adults and microcephaly in infants born to ZIKV-infected women. Like all flaviviruses, ZIKV has a plus-strand RNA genome encoding ten functional proteins (designated C, prM, E, NS1, NS2A, NS2B, NS3, NS4A, NS4B, and NS5). Of these ten, the C (capsid) protein is an essential structural protein required for the formation of infectious viral particles. In order to produce the antiserum specifically recognizing the ZIKV C protein in this study, we expressed and purified the ZIKV C protein as a glutathione-S-transferase (GST) fusion protein in E. coli. The ZIKV C protein-coding region was PCR-amplified using the genomic RNA of ZIKV PRVABC-59, and the amplicons were cloned into the pGEX-4T-1 E. coli expression vector. GST-C fusion proteins were purified using a glutathione sepharose column. Subsequently, the GST-C fusion proteins were used for immunization with rabbits. Western blot analysis using the ZIKV-infected Vero cell lysates were performed to examine the reactivity of the antisera to the ZIKV C protein. Thus, this study provides a useful reagent for the diagnosis and understanding of the viral morphogenesis in the ZIKV-infected cells

    Genetic Elements Involved in Zika Virus Neuropathogenesis

    Get PDF
    Zikavirus (ZIKV) is a mosquito-borne flavivirus(Fig. 1) that is closely related to Japanese encephalitis, West Nile, yellow fever, and dengue viruses. ZIKV was first discovered in Uganda in 1947, but it was not until recent outbreaks, such as through Micronesia in 2007 and through Brazil in 2015 (Fig. 2), that it has been found to be associated with neurological diseases such as Guillain-Barrésyndrome and microcephaly

    A Novel Pinkish-White Flower Color Variant Is Caused by a New Allele of Flower Color Gene W1 in Wild Soybean (Glycine soja)

    Get PDF
    The enzyme flavonoid 3',5'-hydroxylase (F3'5'H) plays an important role in producing anthocyanin pigments in soybean. Loss of function of the W1 locus encoding F3'5'H always produces white flowers. However, few color variations have been reported in wild soybean. In the present study, we isolated a new color variant of wild soybean accession (IT261811) with pinkish-white flowers. We found that the flower's pinkish-white color is caused by w1-s3, a single recessive allele of W1. The SNP detected in the mutant caused amino acid substitution (A(304)S) in a highly conserved SRS4 domain of F3'5'H proteins. On the basis of the results of the protein variation effect analyzer (PROVEAN) tool, we suggest that this mutation may lead to hypofunctional F3'5'H activity rather than non-functional activity, which thereby results in its pinkish-white color

    Genetic and Molecular Characterization of a New EMS-Induced Mutant without the Third Glucose Moiety at the C-3 Sugar Chain of Saponin in Glycine max (L.) Merr.

    Get PDF
    Saponin, a secondary metabolite, is produced by various plant species, including soybean (Glycine max (L.) Merr.). Soybeans synthesize triterpenoid saponins, which are classified by their aglycone structure and sugar chain composition. Here, we characterized an ethyl methanesulfonate-induced mutant, PE1539, without saponin and with a glucose moiety at the third position of the C-3 sugar chain. The saponin phenotype of PE1539 is described by the accumulation of Ab-gamma g saponin and deficiency of Ab-alpha g saponin and DDMP-alpha g saponin, similar to a previously reported sg-3 mutant in soybean. Genetic analysis showed that the saponin phenotype of PE1539 is controlled by a recessive mutation. We mapped the gene responsible for the phenotype of PE1539 and the mapped region included Sg-3 (Glyma.10G104700). Further analysis of Sg-3 in PE1539 using DNA sequencing revealed a single-nucleotide substitution in the exon (G804A), resulting in a premature stop codon; thus, PE1539 produced a PSPG box-truncated protein. Saponin phenotype analysis of the F-2 population-from a cross between wild-type Uram and PE1539-showed that the phenotype of saponin was cosegregated with the genotype of Sg 3. Quantitative real-time PCR showed reduced expression of Sg-3 in PE1539 cells. Together, our data indicate that the saponin phenotype of PE1539 results from a mutation in Sg-3

    Development, Characterization, and Application of Two Reporter-Expressing Recombinant Zika Viruses

    Get PDF
    Zika virus (ZIKV), a mosquito-borne transplacentally transmissible flavivirus, is an enveloped virus with an ~10.8 kb plus-strand RNA genome that can cause neurological disease. To facilitate the identification of potential antivirals, we developed two reporter-expressing ZIKVs, each capable of expressing an enhanced green fluorescent protein or an improved luminescent NanoLuc luciferase. First, a full-length functional ZIKV cDNA clone was engineered as a bacterial artificial chromosome, with each reporter gene under the cap-independent translational control of a cardiovirus-derived internal ribosome entry site inserted downstream of the single open reading frame of the viral genome. Two reporter-expressing ZIKVs were then generated by transfection of ZIKV-susceptible BHK-21 cells with infectious RNAs derived by in vitro run-off transcription from the respective cDNAs. As compared to the parental virus, the two reporter-expressing ZIKVs grew to lower titers with slower growth kinetics and formed smaller foci; however, they displayed a genome-wide viral protein expression profile identical to that of the parental virus, except for two previously unrecognized larger forms of the C and NS1 proteins. We then used the NanoLuc-expressing ZIKV to assess the in vitro antiviral activity of three inhibitors (T-705, NITD-008, and ribavirin). Altogether, our reporter-expressing ZIKVs represent an excellent molecular tool for the discovery of novel antivirals

    Seismic performance of reinforced concrete frames retrofitted with inserted steel frame and adhered waved steel panel

    Get PDF
    In this paper, two types of seismic retrofitting methods for reinforced concrete frames were suggested and examined through the cyclic loading tests: one is to insert a steel frame to existing partially masonry infilled concrete frame of the building after removing masonry from the concrete frame and the other is to adhere waved steel panels to the existing masonry fully infilled concrete frame. In order to evaluate validity of the suggested methods in seismic performance, five specimens were manufactured and tested: a bare concrete frame, a partially masonry infilled concrete frame, a masonry infilled concrete frame, a steel frame inserted concrete frame, and a waved steel panel adhered concrete frame. Compared were crack pattern, failure mode, load-displacement relation, ductility, stiffness and energy dissipation capacity. The specimens retrofitted with the inserted steel frame showed a maximum load approximately twice that of the partially masonry infilled frame, and the specimen retrofitted with the adhered waved steel panel showed a maximum load approximately twice that of the masonry fully infilled frame
    • …
    corecore