scholarly journals The Ablation of Envelope Protein Glycosylation Enhances the Neurovirulence of ZIKV and Cell Apoptosis in Newborn Mice

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Yanqing Guo ◽  
Linlin Bao ◽  
Yanfeng Xu ◽  
Fengdi Li ◽  
Qi Lv ◽  
...  
Keyword(s):  
Cell Apoptosis ◽  
Serial Passage ◽  
Causal Link ◽  
Protein Glycosylation ◽  
Fourth Generation ◽  
Supporting Evidence ◽  
Newborn Mouse ◽  
Newborn Mice ◽  
E Protein ◽  
The Impact

Zika virus (ZIKV) has attracted the wide global attention due to its causal link to microcephaly. In this study, two amino acid (aa) mutation (E143K and R3394K) were identified at the fourth generation (named ZKC2P4) during the serial passage of ZIKV-Asian lineage ZKC2/2016 strain in the newborn mouse brain, while another seven aa deletions in envelope (E) protein were detected in ZKC2P6. ZKC2P6 is a novel nonglycosylated E protein Asian ZIKV we first identified and provides the first direct supporting evidence that glycosylation motif could be lost during the passage in neonatal mice. To study the impact of E protein glycosylation ablation, we compared the pathogenicity of ZKC2P6 with that of ZKC2P4. The results showed that the loss of E protein glycosylation accelerated the disease progression, as evidenced by an earlier weight loss and death, a thinner cerebral cortex, and more serious tissue lesions and inflammation/necrosis. Furthermore, ZKC2P6 exhibited a greater ability to replicate and caused severer cell apoptosis than that of ZKC2P4. Therefore, the ablation of E glycosylation generally enhances the neurovirulence of ZIKV and cell apoptosis in newborn mice.

scholarly journals Site-specific N-glycosylation analysis of animal cell culture-derived Zika virus proteins

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alexander Pralow ◽  
Alexander Nikolay ◽  
Arnaud Leon ◽  
Yvonne Genzel ◽  
Erdmann Rapp ◽  
...  
Keyword(s):  
Zika Virus ◽  
Animal Cell ◽  
Gradient Centrifugation ◽  
Viral Envelope ◽  
Protein Glycosylation ◽  
High Yield ◽  
Structural Protein ◽  
Site Specific ◽  
E Protein ◽  
The Impact

AbstractHere, we present for the first time, a site-specific N-glycosylation analysis of proteins from a Brazilian Zika virus (ZIKV) strain. The virus was propagated with high yield in an embryo-derived stem cell line (EB66, Valneva SE), and concentrated by g-force step-gradient centrifugation. Subsequently, the sample was proteolytically digested with different enzymes, measured via a LC–MS/MS-based workflow, and analyzed in a semi-automated way using the in-house developed glyXtoolMS software. The viral non-structural protein 1 (NS1) was glycosylated exclusively with high-mannose structures on both potential N-glycosylation sites. In case of the viral envelope (E) protein, no specific N-glycans could be identified with this method. Nevertheless, N-glycosylation could be proved by enzymatic de-N-glycosylation with PNGase F, resulting in a strong MS-signal of the former glycopeptide with deamidated asparagine at the potential N-glycosylation site N444. This confirmed that this site of the ZIKV E protein is highly N-glycosylated but with very high micro-heterogeneity. Our study clearly demonstrates the progress made towards site-specific N-glycosylation analysis of viral proteins, i.e. for Brazilian ZIKV. It allows to better characterize viral isolates, and to monitor glycosylation of major antigens. The method established can be applied for detailed studies regarding the impact of protein glycosylation on antigenicity and human pathogenicity of many viruses including influenza virus, HIV and corona virus.

scholarly journals Evidence-Based Use of Cognitive Testing for Academic Interventions: A Critical Appraisal of Meta-Analytic Methodologies

2021 ◽  
Vol 6 ◽  
Author(s):  
Scott L. Decker ◽  
Jessica C. Luedke
Keyword(s):  
Causal Effect ◽  
Causal Link ◽  
Cognitive Testing ◽  
Academic Interventions ◽  
Supporting Evidence ◽  
Neurocognitive Deficits ◽  
Neurocognitive Tests ◽  
Methodological Rigor ◽  
Reporting Discrepancies ◽  
The Impact

Research suggests Specific Learning Disabilities (SLD) are directly linked to specific neurocognitive deficits that result in unexpected learning delays in academic domains for children in schools. However, meta-analytic studies have failed to find supporting evidence for using neurocognitive tests and, consequently, have discouraged their inclusion in SLD identification policies. The current study critically reviews meta-analytic findings and the methodological validity of over 200 research studies used in previous meta-analytic studies to estimate the causal effect of neurocognitive tests on intervention outcomes. Results suggest that only a very small percentage (6–12%) of studies used in previous meta-analytic studies were methodologically valid to estimate a direct effect of cognitive tests on academic intervention outcomes, with the majority of studies having no causal link between neurocognitive tests and intervention outcomes. Additionally, significant reporting discrepancies and inaccurate effect size estimates were found that warranted legitimate concerns for conclusions and policy recommendations provided in several meta-analytic studies. Given the lack of methodological rigor linking cognitive testing to academic interventions in current research, removing neurocognitive testing from learning disability evaluations may be premature. Suggestions for future studies evaluating the impact of neurocognitive tests on intervention outcomes as well as guidelines for synthesizing meta-analytic findings are discussed.

scholarly journals N-Linked Glycosylation of West Nile Virus Envelope Proteins Influences Particle Assembly and Infectivity

2005 ◽  
Vol 79 (21) ◽  
pp. 13262-13274 ◽  
Author(s):  
Sheri L. Hanna ◽  
Theodore C. Pierson ◽  
Melissa D. Sanchez ◽  
Asim A. Ahmed ◽  
Mariam M. Murtadha ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Envelope Proteins ◽  
Glycosylation Site ◽  
Protein Glycosylation ◽  
E Proteins ◽  
Virus Envelope ◽  
West Nile ◽  
Particle Assembly ◽  
E Protein ◽  
The Impact

ABSTRACT West Nile virus (WNV) encodes two envelope proteins, premembrane (prM) and envelope (E). While the prM protein of all WNV strains contains a single N-linked glycosylation site, not all strains contain an N-linked site in the E protein. The presence of N-linked glycosylation on flavivirus E proteins has been linked to virus production, pH sensitivity, and neuroinvasiveness. Therefore, we examined the impact of prM and E glycosylation on WNV assembly and infectivity. Similar to other flaviviruses, expression of WNV prM and E resulted in the release of subviral particles (SVPs). Removing the prM glycosylation site in a lineage I or II strain decreased SVP release, as did removal of the glycosylation site in a lineage I E protein. Addition of the E protein glycosylation site in a lineage II strain that lacked this site increased SVP production. Similar results were obtained in the context of either reporter virus particles (RVPs) or infectious lineage II WNV. RVPs or virions bearing combinations of glycosylated and nonglycosylated forms of prM and E could infect mammalian, avian, and mosquito cells (BHK-21, QT6, and C6/36, respectively). Those particles lacking glycosylation on the E protein were modestly more infectious per genome copy on BHK-21 and QT6 cells, while this absence greatly enhanced the infection of C6/36 cells. Thus, glycosylation of WNV prM and E proteins can affect the efficiency of virus release and infection in a manner that is cell type and perhaps species dependent. This suggests a multifaceted role for envelope N-linked glycosylation in WNV biology and tropism.

scholarly journals N-glycosylation in the Pre-Membrane Protein Is Essential for the Zika Virus Life Cycle

Viruses ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 925
Author(s):  
Yong-Dae Gwon ◽  
Eva Zusinaite ◽  
Andres Merits ◽  
Anna K. Överby ◽  
Magnus Evander
Keyword(s):  
Zika Virus ◽  
Protein Trafficking ◽  
Nuclear Translocation ◽  
Infectious Clone ◽  
Glycosylation Site ◽  
Protein Glycosylation ◽  
Cell Trafficking ◽  
Virion Assembly ◽  
E Protein ◽  
The Impact

Asparagine (N)-linked protein glycosylation plays an important role in protein synthesis and modification. Two Zika virus (ZIKV) structural proteins, the pre-membrane (prM) and envelope (E) protein are N-glycosylated. The prM protein of all ZIKV strains contains a single N-linked glycosylation site, while not all strains contain an N-linked site in the E protein. Our aim was to examine the impact of prM and E N-linked glycosylation on ZIKV infectivity and cell trafficking. Using a ZIKV infectious clone, we found that when the N-glycan sites were removed, the prM- and the prM/E-double mutants did not produce an infectious virus in the supernatant. Further, by using ZIKV prME constructs, we found that N-glycosylation was necessary for effective secretion of ZIKV virions. The absence of the N-glycan on prM or E caused protein aggregation in the rough endoplasmatic reticulum (ER) compartment. The aggregation was more pronounced for the prM-mutation, and the mutant virus lost the ER-Golgi intermediate compartment (ERGIC) localization. In addition, lack of the N-glycan on prM induced nuclear translocation of CCAAT-enhancer-binding protein homologous protein (CHOP), an ER stress marker. To conclude, we show that the prM N-glycan is essential for the ZIKV infectious cycle, and plays an important role in viral protein trafficking, protein folding, and virion assembly.

The Impact of Mobile Gadget in EFL Learning: Perceptions of EFL Undergraduates

2018 ◽  
Vol 7 (1) ◽  
Author(s):  
Imam - Fauzi
Keyword(s):  
Self Report ◽  
Fourth Generation ◽  
Learning Activity ◽  
Advanced Country ◽  
Innovative Methods ◽  
Phone Calls ◽  
Teachers And Students ◽  
Efl Students ◽  
The Impact ◽  
Efl Learning

AbstractMost of young people are enthusiasticin having the most recent mobile gadgets just to boast among their peers. They likely utilize them to make phone calls, take pictures, listen to songs, watch videos, or surf the internet access for learning or just entertainment. In a technologically advanced country like Indonesia, the third and fourth generation (3G, 4G) mobile devices are available at affordable prices, and people of all streams find it necessary to own a mobile gadget for connecting and communicating.  Moreover, it has become a common trend among undergraduates to carry a mobile gadget to the classroom as well.In this paper, the researcher emphasize the potential of mobile gadgets as a learning tool for students and have incorporated them into the learning environment.The present study examines the application of mobile gadgetin EFL learning and investigates the perceptions of EFL students about mobile gadget in learning activity.  A field study was conducted on thirty undergraduatestudents majoring in accounting study Serang Raya University.  The methodology of data collection included a self-report for students and teachers’ and students’ questionnaire. Findings of the research are significant for EFL teachers and researchers for introducing innovative methods and helpful materials for the English classroom.Keywords: Mobile gadget, students’ perception, teachers’ perception..

scholarly journals Influenza With an Infiltrate: Investigating the New Community-Acquired Pneumonia Guidelines

2020 ◽  
Vol 41 (S1) ◽  
pp. s302-s302
Author(s):  
Amanda Barner ◽  
Lou Ann Bruno-Murtha
Keyword(s):  
Demographic Data ◽  
Retrospective Chart Review ◽  
Vaccination Rate ◽  
Community Acquired Pneumonia ◽  
Teaching Hospitals ◽  
Antibiotic Prescribing ◽  
Supporting Evidence ◽  
Radiographic Findings ◽  
Significant Difference ◽  
The Impact

Background: The Infectious Diseases Society of America released updated community-acquired pneumonia (CAP) guidelines in October 2019. One of the recommendations, with a low quality of supporting evidence, is the standard administration of antibiotics in adult patients with influenza and radiographic evidence of pneumonia. Procalcitonin (PCT) is not endorsed as a strategy to withhold antibiotic therapy, but it could be used to de-escalate appropriate patients after 48–72 hours. Radiographic findings are not indicative of the etiology of pneumonia. Prescribing antibiotics for all influenza-positive patients with an infiltrate has significant implications for stewardship. Therefore, we reviewed hospitalized, influenza-positive patients at our institution during the 2018–2019 season, and we sought to assess the impact of an abnormal chest x-ray (CXR) and PCT on antibiotic prescribing and outcomes. Methods: We conducted a retrospective chart review of all influenza-positive admissions at 2 urban, community-based, teaching hospitals. Demographic data, vaccination status, PCT levels, CXR findings, and treatment regimens were reviewed. The primary outcome was the difference in receipt of antibiotics between patients with a negative (<0.25 ng/mL) and positive PCT. Secondary outcomes included the impact of CXR result on antibiotic prescribing, duration, 30-day readmission, and 90-day mortality. Results: We reviewed the medical records of 117 patients; 43 (36.7%) received antibiotics. The vaccination rate was 36.7%. Also, 11% of patients required intensive care unit (ICU) admission and 84% received antibiotics. Moreover, 109 patients had a CXR: 61 (55.9%) were negative, 29 (26.6%) indeterminate, and 19 (17.4%) positive per radiologist interpretation. Patients with a positive PCT (OR, 12.7; 95% CI, 3.43–60.98; P < .0007) and an abnormal CXR (OR, 7.4; 95% CI, 2.9–20.1; P = .000003) were more likely to receive antibiotics. There was no significant difference in 30-day readmission (11.6% vs 13.5%; OR, 0.89; 95% CI, 0.21–3.08; P = 1) and 90-day mortality (11.6% vs 5.4%; OR, 2.37; 95% CI, 0.48–12.75; P = .28) between those that received antibiotics and those that did not, respectively. Furthermore, 30 patients (62.5%) with an abnormal CXR received antibiotics and 21 (43.7%) had negative PCT. There was no difference in 30-day readmission or 90-day mortality between those that did and did not receive antibiotics. Conclusions: Utilization of PCT allowed selective prescribing of antibiotics without impacting readmission or mortality. Antibiotics should be initiated for critically ill patients and based on clinical judgement, rather than for all influenza-positive patients with CXR abnormalities.Funding: NoneDisclosures: None

scholarly journals 1457. Serial Passage of Enterobacteriaceae to Explore Development of Carbapenem Resistance

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S731-S731
Author(s):  
Yosef Nissim ◽  
Douglas Slain ◽  
P Rocco LaSala
Keyword(s):  
Susceptibility Testing ◽  
Klebsiella Oxytoca ◽  
Carbapenem Resistance ◽  
Serial Passage ◽  
Resistant Isolate ◽  
Mueller Hinton ◽  
The Us ◽  
Zones Of Inhibition ◽  
Mueller Hinton Agar ◽  
The Impact

Abstract Background Carbapenems are broad-spectrum antibacterials that have seen increased usage for the Enterobacteriales family in recent years. While carbapenem usage has been associated with increased antibacterial resistance, there is currently a lack of data comparing the risk of reduced susceptibility selection by the two most commonly used carbapenems in the US, ertapenem (ERT) and meropenem (MER). We conducted a novel serial passage experiment with clinical isolates of Enterobacteriales to assess the impact of repeated exposure to ERT or MER on phenotypic susceptibility patterns. Methods Non-duplicate clinical Enterobacteriales isolates were selected randomly for inclusion. Antimicrobial susceptibility testing was performed by CLSI disc diffusion methods. Standardized suspensions of isolates were plated on Mueller-Hinton agar, and ERT (10mcg) and MER (10mcg) discs applied. Zones of inhibition were measured and recorded after 16-18 hours incubation. Growth from the innermost zone of inhibition around each disc was used to prepare subsequent suspensions for serial susceptibility testing. This process would be repeated daily for 10 days. Each subsequent serially-passaged isolated was tested against both ERT and MER. Daily zones of inhibition were measured and interpreted. Baseline & final susceptibilities were determined by automated methods (Vitek 2). Results Seventeen Enterobacteriaceae isolates were selected, including: Klebsiella pneumoniae (n=11), Klebsiella oxytoca (n=2), Escherichia coli (n=1), Morganella morganii (n=1), and Enterobacter cloacae (n=2). Despite a greater degree of reductions in zones of inhibition with repeated ERT exposure (vs MER), the overall 10 day trends were not found to be significant different (P=0.529). Resistance developed to ERT in six isolates compared to one MER-resistant isolate (P = 0.053). E. cloacae was the only species to show a significant change between drugs (P=0.010). Two of three isolates that developed reduced zone changes &gt; 10mm to MER were initially exposed to ERT on an earlier plate. Conclusion This novel experiment identified the development of some nonsignificant reductions in susceptibility with ERT after serial exposure. Results from this pilot study should encourage larger well-designed studies in this area. Disclosures All Authors: No reported disclosures

Impact of linguistic ostracism on knowledge sharing, hiding and hoarding and the moderating role of cultural intelligence

Kybernetes ◽  
2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mohammad Jamal Albana ◽  
Mehmet Yeşiltaş
Keyword(s):  
Knowledge Sharing ◽  
Cultural Intelligence ◽  
Causal Link ◽  
Equation Modeling ◽  
Content Type ◽  
Knowledge Hoarding ◽  
Knowledge Hiding ◽  
The Impact ◽  
Moderating Role

PurposeDrawing on the theory of belongingness, this study scrutinizes the impact of linguistic ostracism on knowledge sharing, knowledge hiding and knowledge hoarding and the moderating role of cultural intelligence (CQ) in a diverse and multi-cultural work setting.Design/methodology/approachA two-phase sampling of judgmental and random sampling techniques was used to recruit local and foreign workers in the Jordanian service industry. The present study empirically analyzes the sample of 394 employees' responses by applying variance-based structural equation modeling (VB-SEM).FindingsVB-SEM results indicate that linguistic ostracism lessens knowledge sharing behavior and heightens knowledge hiding and hoarding. CQ moderates two of the said associations, specifically by buffering the causal link between linguistic ostracism and knowledge hiding, as well as linguistic ostracism and knowledge hoarding. Consequently, CQ did not moderate the causal link between linguistic ostracism and knowledge sharing.Practical implicationsThe study's findings can help managers and decision-makers in such workplaces better understand the deleterious effects of linguistic ostracism and how CQ functions as a buffer. The study concludes with theoretical and managerial implications.Originality/valueVery few investigations have been conducted to determine the consequences of linguistic ostracism in today's multi-cultural and diverse work environment. This paper is among the first to unveil the association of linguistic ostracism and CQ with various knowledge management (KM) concepts.

scholarly journals Passive Immunity to Vibrio cholerae O1 Afforded by a Human Monoclonal IgA1 Antibody Expressed in Milk

2020 ◽  
Vol 5 (1) ◽  
pp. 89 ◽  
Author(s):  
Danielle E. Baranova ◽  
Lihow Chen ◽  
Margaret Destrempes ◽  
Harry Meade ◽  
Nicholas J. Mantis
Keyword(s):  
Vibrio Cholerae ◽  
Bacterial Colonization ◽  
Transgenic Animals ◽  
Control Measures ◽  
Newborn Mouse ◽  
Newborn Mice ◽  
Variable Regions ◽  
Transgenic Mouse Line ◽  
Experimental Cholera

Background: In cholera epidemics, the spread of disease can easily outpace vaccine control measures. The advent of technologies enabling the expression of recombinant proteins, including antibodies, in the milk of transgenic animals raises the prospect of developing a self-administered and cost-effective monoclonal antibody (MAb)-based prophylactic to reduce the incidence of Vibrio cholerae infection.Methods: We generated a transgenic mouse line in which the heavy and light chain variable regions (Fv) specific for a conserved epitope in the core/lipid A of V. cholerae O1 lipopolysaccharide were expressed as a full-length human dimeric IgA1 (ZAC-3) and secreted into the milk of lactating dams. Milk containing ZAC-3 IgA1 was assessed for the ability to passively protect against experimental cholera infection in a newborn mouse model and to impact bacterial swimming behavior.Results: Newborn mice that were passively administered ZAC-3 IgA1 containing milk, or that suckled on dams expressing ZAC-3 IgA1, were immune to experimental cholera infection, as measured by a reduction of V. cholerae O1 colony forming units recovered from intestinal lysates 12 hours after oral challenge. In vitro analysis revealed that ZAC-3 hIgA1-containing milk arrested V. cholerae motility in soft agar and liquid media and was effective at promoting bacterial agglutination, possibly accounting for the observed reduction in bacterial colonization in vivo.Conclusions: These results demonstrate that consumption of milk-derived antibodies may serve as a strategy to passively protect against cholera and possibly other enteric pathogens.

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