1,613 research outputs found

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

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    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

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

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    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

    Induction of inflammatory cytokines and toll-like receptors in chickens infected with avian H9N2 influenza virus

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    H9N2 influenza virus is endemic in many Asian countries and is regarded as a candidate for the next human pandemic. Knowledge of the induction of inflammatory responses and toll-like receptors (TLRs) in chickens infected with H9N2 is limited. Here, we show that H9N2 induces pro-inflammatory cytokines such as transforming growth factor-beta 3; tumor necrosis factor-alpha; interferon-alpha, -beta, and gamma; and TLR 1, 2, 3, 4, 5, 7, and 15 in trachea, lung, and intestine of infected chickens. In the lung, TLR-15 was dominantly induced. Taken together, it seems that H9N2 infections efficiently induce inflammatory cytokines and TLRs in trachea, lung and intestine of chickens

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

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    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

    Comparison of the effects of sugammadex and neostigmine on hospital stayin robot-assisted laparoscopic prostatectomy: a retrospective study

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    Abstract Background Sugammadex reduces postoperative complications. We sought to determine whether it could reduce the length of hospital stay, post-anesthetic recovery time, unplanned readmission, and charges for patients who underwent robot-assisted laparoscopic prostatectomy (RALP) when compared to neostigmine. Methods This was a retrospective observational study of patients who underwent RALP between July 2012 and July 2017, in whom rocuronium was used as a neuromuscular blocker. The primary outcome was the length of hospital stay after surgery in patients who underwent reversal with sugammadex when compared to those who underwent reversal with neostigmine. The secondary outcomes were post-anesthetic recovery time, hospital charges, and unplanned readmission within 30 days after RALP. Results In total, 1430 patients were enrolled. Using a generalized linear model in a propensity score-matched cohort, sugammadex use was associated with a 6% decrease in the length of hospital stay (mean: sugammadex 7.7 days vs. neostigmine 8.2 days; odds ratio [OR] 0.94, 95% confidence interval [CI] [0.89, 0.98], P = 0.008) and an 8% decrease in post-anesthetic recovery time (mean: sugammadex 36.7 min vs. neostigmine 40.2 min; OR 0.92, 95% CI [0.90, 0.94], P < 0.001) as compared to neostigmine use; however, it did not reduce the 30-day unplanned readmission rate (P = 0.288). The anesthesia charges were higher in the sugammadex group than in the neostigmine group (P < 0.001); however, there were no significant differences between the groups in terms of postoperative net charges (P = 0.061) and total charges (P = 0.100). Conclusions Compared to the reversal of rocuronium effects with neostigmine, reversal with sugammadex after RALP was associated with a shorter hospital stay and post-anesthetic recovery time, and was not associated with 30-day unplanned readmission rates and net charges

    Could Fractional Exhaled Nitric Oxide Test be Useful in Predicting Inhaled Corticosteroid Responsiveness in Chronic Cough? A Systematic Review

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    © 2016 Background Fractional exhaled nitric oxide (FENO) is a safe and convenient test for assessing T H 2 airway inflammation, which is potentially useful in the management of patients with chronic cough. Objective To summarize the current evidence on the diagnostic usefulness of FENO for predicting inhaled corticosteroid (ICS) responsiveness in patients with chronic cough. Methods A systematic literature review was conducted to identify articles published in peer-reviewed journals up to February 2015, without language restriction. We included studies that reported the usefulness of FENO (index test) for predicting ICS responsiveness (reference standard) in patients with chronic cough (target condition). The data were extracted to construct a 2 × 2 accuracy table. Study quality was assessed with Quality Assessment of Diagnostic Accuracy Studies 2. Results We identified 5 original studies (2 prospective and 3 retrospective studies). We identified considerable heterogeneities in study design and outcome definitions, and thus were unable to perform a meta-analysis. The proportion of ICS responders ranged from 44% to 59%. Sensitivity and specificity ranged from 53% to 90%, and from 63% to 97%, respectively. The reported area under the curve ranged from abou t 0.60 to 0.87; however, studies with a prospective design and a lower prevalence of asthma had lower area under the curve values. None measured placebo effects or objective cough frequency. Conclusions We did not find strong evidence to support the use of FENO tests for predicting ICS responsiveness in chronic cough. Further studies need to have a randomized, placebo-controlled design, and should use validated measurement tools for cough. Standardization would facilitate the development of clinical evidence

    Necrotizing fasciitis and streptococcal toxic shock syndrome secondary to varicella in a healthy child

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    Varicella is usually considered to be a benign disease in healthy children; however, serious complications can occur such as necrotizing fasciitis and toxic shock syndrome. We describe a 38-month-old girl with necrotizing fasciitis and streptococcal toxic shock syndrome following varicella. She was previously healthy and vaccinated against varicella at 12 months of age. She had been diagnosed with varicella three days prior to presenting at our facility; she developed fever, vomiting, and painful swelling on her left flank. Her skin lesions worsened, she became lethargic, and had episodes of hypotension and coagulopathy. Necrotizing fasciitis on the left abdominal wall, buttocks, and left thigh was diagnosed by magnetic resonance imaging, and group A Streptococcus was isolated from a tissue culture. She was diagnosed as necrotizing fasciitis and streptococcal toxic shock syndrome, and successfully treated with repeated surgical debridement and fasciotomy, in addition to intensive antibiotics. Our experience suggests that necrotizing fasciitis in patients with varicella should be considered to be a rare complication even with widespread vaccine use. Early diagnosis and intensive treatment are required to prevent a fatal outcome

    Pentoxifylline Attenuates Methionine- and Choline-Deficient-Diet-Induced Steatohepatitis by Suppressing TNF- α

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    Background. Pentoxifylline (PTX) anti-TNF properties are known to exert hepatoprotective effects in various liver injury models. The aim of this study was to investigate whether PTX has beneficial roles in the development of methionine- and choline-deficient-(MCD-) diet-induced NAFLD SD rats in vivo and TNF-α-induced Hep3B cells in vitro. Methods. SD Rats were classified according to diet (chow or MCD diet) and treatment (normal saline or PTX injection) over a period of 4 weeks: group I (chow + saline, n=4), group II (chow + PTX), group III (MCD + saline), and group IV (MCD + PTX). Hep3B cells were treated with 100 ng/ml TNF-α (24 h) in the absence or presence of PTX (1 mM). Results. PTX attenuated MCD-diet-induced serum ALT levels and hepatic steatosis. In real-time PCR and western blotting analysis, PTX decreased MCD-diet-induced TNF-alpha mRNA expression and proapoptotic unfolded protein response by ER stress (GRP78, p-eIF2, ATF4, IRE1α, CHOP, and p-JNK activation) in vivo. PTX (1 mM) reduced TNF-α-induced activation of GRP78, p-eIF2, ATF4, IRE1α, and CHOP in vitro. Conclusion. PTX has beneficial roles in the development of MCD-diet-induced steatohepatitis through partial suppression of TNF-α and ER stress
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